JP5024160B2 - vehicle - Google Patents

Description

  The present invention relates to a vehicle using posture control of an inverted pendulum.

  Conventionally, a technique related to a vehicle using posture control of an inverted pendulum has been proposed. For example, a vehicle that has two drive wheels arranged on the same axis, detects a change in the posture of the vehicle body due to the movement of the center of gravity of the driver, and drives the vehicle body attached to a single spherical drive wheel. Techniques for vehicles that move while being controlled have been proposed (see, for example, Patent Document 1).

In this case, the vehicle is stopped or moved by controlling the operation of the rotating body while detecting the balance of the vehicle body and the state of the operation with the sensor.
JP 2007-219986 A

  However, in the conventional vehicle, when the driver gives a command to step up, but the step is too high to go up, or the driver steps up the step while suddenly accelerating or goes down the step while suddenly decelerating. When the driver instructs a correct operation, the vehicle body may be greatly tilted or the vehicle may be accelerated or decelerated so that the driver feels unnatural. At this time, the driver may feel uncomfortable with these movements or feel uneasy about the stability and safety of the vehicle.

  The cause of this phenomenon is that the upper and lower limits of the vehicle acceleration target value are set to constant values that do not depend on the road surface condition, and the effect of the step on the acceleration / deceleration performance of the vehicle is not considered. It is done.

  In addition, as one of means for solving this problem, there is a method of switching from a control method during normal driving to another special control method when, for example, the level difference is high and cannot be climbed, but at the time of switching the control method There are many problems such as a sense of discomfort given to the driver, complicated control algorithm and program, and occurrence of a phenomenon in which switching is repeated intermittently in the vicinity of a threshold value for switching the control method. Therefore, it is desirable to realize stable control of the vehicle body posture and the running state by a simple and stable control method as much as possible.

  The present invention solves the problems of the conventional vehicle, appropriately evaluates the limit value of the vehicle acceleration when raising and lowering the step, and limits the target value of the vehicle acceleration with the limit value, thereby increasing the step difference. It is an object of the present invention to provide a vehicle that can always maintain stable vehicle operation even when entering, and can travel safely and comfortably even in places with high steps.

For this purpose, the vehicle of the present invention has a vehicle body, a drive wheel that is rotatably attached to the vehicle body, and a vehicle control device that controls the posture of the vehicle body by controlling the drive torque applied to the drive wheel. The vehicle control device limits the target value of the vehicle acceleration according to the limit value of the vehicle acceleration that is determined according to the step resistance torque that is the resistance due to the step when moving up and down the step on the road surface.

  In still another vehicle of the present invention, the vehicle control device further determines a limit value of the vehicle acceleration based on a limit of vehicle travel control and a limit of vehicle body posture control when moving up and down the step.

  In another vehicle of the present invention, the vehicle further includes an active weight portion movably attached to the vehicle body, and the vehicle control device includes the vehicle according to a movement limit position of the active weight portion. Determine the limit value of acceleration.

  According to the configuration of the first aspect, by limiting the target value of the vehicle acceleration when moving up and down the level difference, for example, an unrealizable target driving state is set such that the vehicle passes while accelerating a very high level difference. Therefore, stable vehicle operation can be maintained by controlling an appropriate target. For example, stable vehicle operation can be maintained even when the vehicle goes up a step while decelerating, or when it turns back without being able to climb the step.

According to the configuration of the second aspect , by considering the limits of the vehicle travel control and the vehicle body posture control, the vehicle acceleration state and the vehicle body posture are reliably stabilized by determining the vehicle acceleration limit more accurately. In addition, it is possible to maximize the step-up / down performance of the vehicle.

According to the configuration of the third aspect , the necessary movement amount of the center of gravity of the vehicle body can be achieved without accompanying the inclination of the vehicle body.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic diagram showing the configuration of a vehicle in a first embodiment of the present invention, and shows a state in which an occupant is moving forward in an accelerated state, and FIG. 2 is a first embodiment of the present invention. 1 is a block diagram showing a configuration of a vehicle control system in FIG.

  In FIG. 1, reference numeral 10 denotes a vehicle according to the present embodiment, which includes a body portion 11, a drive wheel 12, a support portion 13, and a riding portion 14 on which an occupant 15 rides. Can be tilted. Then, the posture of the vehicle body is controlled similarly to the posture control of the inverted pendulum. In the example shown in FIG. 1, the vehicle 10 is accelerating in the direction indicated by the arrow A, and the vehicle body is tilted in the traveling direction.

  The drive wheel 12 is rotatably supported with respect to a support portion 13 that is a part of the vehicle body, and is driven by a drive motor 52 as a drive actuator. The axis of the drive wheel 12 exists in a direction perpendicular to the plane shown in FIG. 1, and the drive wheel 12 rotates around that axis. The drive wheel 12 may be singular or plural, but in the case of plural, the drive wheels 12 are arranged on the same axis in parallel. In the present embodiment, description will be made assuming that there are two drive wheels 12. In this case, each drive wheel 12 is independently driven by an individual drive motor 52. As the drive actuator, for example, a hydraulic motor, an internal combustion engine, or the like can be used, but here, the description will be made assuming that the drive motor 52 that is an electric motor is used.

  The main body 11 that is a part of the vehicle body is supported from below by the support 13 and is positioned above the drive wheels 12. The main body 11 has a riding section 14 that functions as an active weight section so that it can move relative to the main body 11 in the front-rear direction of the vehicle 10, in other words, relative to the tangential direction of the vehicle body rotation circle. It is attached so as to be movable.

  Here, the active weight part has a certain amount of mass, and actively corrects the position of the center of gravity of the vehicle 10 by moving it back and forth with respect to the main body part 11. The active weight portion does not necessarily need to be the riding portion 14. For example, the active weight portion may be a device in which a heavy peripheral device such as a battery is movably attached to the main body portion 11, a weight, a weight (Weight), a device in which a dedicated weight member such as a balancer is movably attached to the main body 11 may be used. Moreover, you may use together the boarding part 14, a heavy peripheral device, an exclusive weight member, etc.

  Further, in the present embodiment, for convenience of explanation, an example in which the riding part 14 in a state in which the occupant 15 is boarded functions as an active weight part will be described, but the occupant 15 is not necessarily in the riding part 14. For example, when the vehicle 10 is operated by remote control, the occupant 15 may not be on the riding section 14, or cargo may be loaded instead of the occupant 15.

  The riding section 14 is the same as a seat used in automobiles such as passenger cars and buses, and includes a seat surface section 14a, a backrest section 14b, and a headrest 14c, and is attached to the main body section 11 through a moving mechanism (not shown). ing.

  The moving mechanism includes a low-resistance linear moving mechanism such as a linear guide device and an active weight part motor 62 as an active weight part actuator. The active weight part motor 62 drives the riding part 14, and the main body part 11. The vehicle is moved back and forth in the vehicle traveling direction. As the active weight actuator, for example, a hydraulic motor, a linear motor, or the like can be used. However, here, the description will be made assuming that the active weight motor 62 that is a rotary electric motor is used.

  The linear guide device includes, for example, a guide rail attached to the main body 11, a carriage attached to the riding part 14 and sliding along the guide rail, a ball, a roller, and the like interposed between the guide rail and the carriage. Rolling elements. In the guide rail, two track grooves are formed linearly along the longitudinal direction on the left and right side surfaces thereof. Moreover, the cross section of the carriage is formed in a U-shape, and two track grooves are formed on the inner sides of the two opposing side surfaces so as to face the track grooves of the guide rail. The rolling elements are incorporated between the raceway grooves, and roll in the raceway grooves with the relative linear motion of the guide rail and the carriage. The carriage is formed with a return passage that connects both ends of the raceway groove, and the rolling elements circulate through the raceway groove and the return passage.

  The linear guide device includes a brake or a clutch that fastens the movement of the linear guide device. When the operation of the riding section 14 is unnecessary, such as when the vehicle 10 is stopped, the relative positional relationship between the main body section 11 and the riding section 14 is maintained by fixing the carriage to the guide rail with a brake. . When the operation is necessary, the brake is released and the distance between the reference position on the main body 11 side and the reference position on the riding section 14 is controlled to be a predetermined value.

  An input device 30 including a joystick 31 as a target travel state acquisition device is disposed beside the boarding unit 14. The occupant 15 controls the vehicle 10 by operating a joystick 31 as a control device, that is, inputs a travel command such as acceleration, deceleration, turning, in-situ rotation, stop, and braking of the vehicle 10. ing. If the occupant 15 can operate and input a travel command, other devices such as a pedal, a handle, a jog dial, a touch panel, and a push button can be obtained instead of the joystick 31 to obtain a target travel state. It can also be used as a device.

  In addition, when the vehicle 10 is steered by remote control, it can replace with the said joystick 31, and can use the receiver which receives the driving | running | working command from a controller with a wire communication or a radio | wireless as a target driving state acquisition apparatus. Further, when the vehicle 10 automatically travels according to predetermined travel command data, a data reader that reads travel command data stored in a storage medium such as a semiconductor memory or a hard disk is used as a target travel instead of the joystick 31. It can be used as a status acquisition device.

  In addition, the vehicle 10 includes a control ECU (Electronic Control Unit) 20 as a vehicle control device, and the control ECU 20 includes a main control ECU 21, a drive wheel control ECU 22, and an active weight unit control ECU 23. The control ECU 20, main control ECU 21, driving wheel control ECU 22 and active weight unit control ECU 23 include calculation means such as a CPU and MPU, storage means such as a magnetic disk and semiconductor memory, input / output interfaces, and the like. A computer system that controls the operation. For example, the computer system is disposed in the main body 11, but may be disposed in the support portion 13 or the riding portion 14. The main control ECU 21, the drive wheel control ECU 22, and the active weight control ECU 23 may be configured separately or may be configured integrally.

  The main control ECU 21 functions as a part of the drive wheel control system 50 that controls the operation of the drive wheel 12 together with the drive wheel control ECU 22, the drive wheel sensor 51, and the drive motor 52. The drive wheel sensor 51 includes a resolver, an encoder, and the like, functions as a drive wheel rotation state measuring device, detects a drive wheel rotation angle and / or rotation angular velocity indicating a rotation state of the drive wheel 12, and transmits it to the main control ECU 21. To do. The main control ECU 21 transmits a drive torque command value to the drive wheel control ECU 22, and the drive wheel control ECU 22 supplies an input voltage corresponding to the received drive torque command value to the drive motor 52. The drive motor 52 applies drive torque to the drive wheels 12 in accordance with the input voltage, thereby functioning as a drive actuator.

  The main control ECU 21 functions as a part of the active weight part control system 60 that controls the operation of the riding part 14 that is the active weight part together with the active weight part control ECU 23, the active weight part sensor 61, and the active weight part motor 62. To do. The active weight part sensor 61 is composed of an encoder or the like, functions as an active weight part movement state measuring device, detects the active weight part position and / or movement speed indicating the movement state of the riding part 14, and transmits it to the main control ECU 21. To do. Further, the main control ECU 21 transmits an active weight part thrust command value to the active weight part control ECU 23, and the active weight part control ECU 23 sends an input voltage corresponding to the received active weight part thrust command value to the active weight part motor. 62. The active weight motor 62 applies thrust to the riding section 14 to translate the riding section 14 in accordance with the input voltage, thereby functioning as an active weight actuator.

  Further, the main control ECU 21 functions as a part of the vehicle body control system 40 that controls the posture of the vehicle body together with the drive wheel control ECU 22, the active weight unit control ECU 23, the vehicle body inclination sensor 41, the drive motor 52, and the active weight unit motor 62. . The vehicle body tilt sensor 41 includes an acceleration sensor, a gyro sensor, and the like, and functions as a vehicle body tilt state measuring device. The vehicle body tilt sensor 41 detects a vehicle body tilt angle and / or tilt angular velocity indicating the tilt state of the vehicle body, and transmits the detected vehicle body tilt angle to the main control ECU 21. The main control ECU 21 transmits a drive torque command value to the drive wheel control ECU 22 and transmits an active weight portion thrust command value to the active weight portion control ECU 23.

  The main control ECU 21 receives a travel command from the joystick 31 of the input device 30. Then, the main control ECU 21 transmits a drive torque command value to the drive wheel control ECU 22 and transmits an active weight portion thrust command value to the active weight portion control ECU 23.

  Further, the control ECU 20 functions as a step resistance torque estimating means for estimating the step resistance torque based on the travel state of the vehicle 10 and the time change of the vehicle body posture. Further, it functions as a target vehicle body posture determination means for determining a target vehicle body posture, that is, a vehicle body tilt state and / or an active weight portion movement state, according to the target travel state and the step resistance torque. Furthermore, it functions as an actuator output determining means that determines the output of each actuator according to the traveling state and vehicle body posture of the vehicle 10 acquired by each sensor, and the target traveling state, target vehicle body posture, and step resistance torque. Specifically, it functions as step elevation torque determining means for determining the drive torque to be added according to the step resistance torque, and center of gravity correction amount determining means for determining the center of gravity correction amount of the vehicle body according to the step elevation torque.

  Each sensor may acquire a plurality of state quantities. For example, an acceleration sensor and a gyro sensor may be used together as the vehicle body tilt sensor 41, and the vehicle body tilt angle and the vehicle body tilt angular velocity may be determined from the measured values of both.

  Next, the operation of the vehicle 10 configured as described above will be described. First, an outline of the travel and attitude control process will be described.

  FIG. 3 is a schematic view showing the step-up / down operation of the vehicle in the first embodiment of the present invention, and FIG. 4 is a flowchart showing the operation of the vehicle travel and attitude control processing in the first embodiment of the present invention. . FIG. 3A shows an operation example according to the prior art for comparison, and FIG. 3B shows an operation according to the present embodiment.

  In the case of a conventional vehicle as described in the “Background Art” section, as shown in FIG. 3A, the reaction of the drive torque applied to the drive wheels 12 to climb up the step, that is, the anti-torque is applied to the vehicle body. The vehicle body tilts backward. For this reason, it is not possible to perform stable vehicle body posture and travel control when riding on a step.

  In contrast, in the present embodiment, the riding section 14 functions as an active weight section, and as shown in FIG. 3B, the center of gravity of the vehicle 10 is set by moving the riding section 14 forward. Move forward. As a result, a gravitational torque is applied to tilt the vehicle body forward, so that the reaction when driving torque is applied to the drive wheel 12 for climbing the step, that is, even if the anti-torque acts on the vehicle body, Since the action is canceled out by the torque, the vehicle body does not tilt backward. Therefore, stable vehicle body posture and travel control can be performed even when riding on a step.

  Note that this embodiment is particularly effective when entering a step from a stopped state and a low-speed traveling state, that is, when the inertial force acting on the vehicle body as the vehicle decelerates due to contact with the step is small.

  Further, the driving torque for climbing up the step is estimated in real time during the climbing operation and applied to the drive wheels 12. As a result, stable riding is possible for any step shape and vehicle speed.

  In other words, in the present embodiment, the vehicle 10 can move up and down in a stable manner by executing the travel and posture control processing including the correction of the center of gravity of the vehicle 10 and the application of drive torque.

  In the running and posture control process, the control ECU 20 first executes a state quantity acquisition process (step S1), and the driving wheel is driven by each sensor, that is, the driving wheel sensor 51, the vehicle body tilt sensor 41, and the active weight sensor 61. 12 rotation states, vehicle body inclination states, and riding portion 14 movement states are acquired.

  Next, the control ECU 20 executes a step elevation torque determination process (step S2), and the state quantity acquired by the state quantity acquisition process, that is, the rotational state of the drive wheels 12, the tilt state of the vehicle body, and / or the riding section 14 is obtained. The step resistance torque is estimated by an observer on the basis of the movement state of each and the output value of each actuator, that is, the output value of the drive motor 52 and / or the active weight motor 62, and the step elevation torque is determined. Here, the observer is a method of observing the internal state of the control system based on a dynamic model, and is configured by wired logic or soft logic.

  Next, the control ECU 20 executes a target travel state determination process (step S3), and based on the operation amount of the joystick 31, the target value of the acceleration of the vehicle 10 and the target value of the rotational angular velocity of the drive wheels 12 are obtained. decide.

  Next, the control ECU 20 executes a target body posture determination process (step S4), and the step lift torque determined by the step lift torque determination process and the acceleration of the vehicle 10 determined by the target travel state determination process. Based on the target value, the target value of the vehicle body posture, that is, the target value of the vehicle body inclination angle and the active weight portion position is determined.

  Finally, the control ECU 20 executes an actuator output determination process (step S5), each state quantity acquired by the state quantity acquisition process, the step lift torque determined by the step lift torque determination process, and the target travel state The output of each actuator, that is, the output of the drive motor 52 and the active weight motor 62, is determined based on the target travel state determined by the determination processing of the target vehicle body and the target vehicle body posture determined by the determination processing of the target vehicle body posture. To do.

  Next, details of the traveling and attitude control processing will be described. First, the state quantity acquisition process will be described.

  FIG. 5 is a diagram showing a vehicle dynamic model and its parameters according to the first embodiment of the present invention, and FIG. 6 is a flowchart showing an operation of state quantity acquisition processing according to the first embodiment of the present invention.

In the present embodiment, state quantities and parameters are represented by the following symbols. FIG. 5 shows some of the state quantities and parameters.
θ _W : Drive wheel rotation angle (average of two drive wheels) [rad]
θ ₁ : Body tilt angle (vertical axis reference) [rad]
λ _S : Active weight part position (vehicle center point reference) [m]
τ _W : Driving torque (total of two driving wheels) [Nm]
S _S : Active weight part thrust [N]
g: Gravity acceleration [m / s ² ]
m _W : Drive wheel mass (total of two drive wheels) [kg]
R _W : Driving wheel contact radius [m]
I _W : Moment of inertia of driving wheel (total of two driving wheels) [kgm ² ]
D _W : viscosity damping coefficient [Nms / rad] for driving wheel rotation
m ₁ : Body mass (including active weight) [kg]
l ₁ : Body center-of-gravity distance (from axle) [m]
I ₁ : Body inertia moment (around the center of gravity) [kgm ² ]
D ₁ : Viscous damping coefficient for vehicle body tilt [Nms / rad]
m _S : Active weight part mass [kg]
l _S : Active weight part center of gravity distance (from axle) [m]
I _S : Active weight part inertia moment (around the center of gravity) [kgm ² ]
D _S : Viscosity damping coefficient [Ns / rad] for active weight part translation

  Next, the step elevation torque determination process will be described.

  FIG. 7 is a flowchart showing the operation of the step elevation torque determination process in the first embodiment of the present invention.

In the step elevation torque determination process, the main control ECU 21 first estimates the step resistance torque τ _D (step S2-1). In this case, based on each state quantity acquired in the state quantity acquisition process and the output of each actuator determined in the actuator output determination process in the previous (previous time step) travel and posture control process, The step resistance torque τ _D is estimated from (1).

Subsequently, the main control ECU 21 determines the step elevation torque τ _C (step S2-2). In this case, the estimated value of the step resistance torque τ _D is set as the value of the step lifting torque τ _C. That is, τ _C = τ _D.

  As described above, in the present embodiment, based on the driving torque output from the driving motor 52, the driving wheel rotation angular acceleration indicating the vehicle translational acceleration as the state quantity, the vehicle body inclination angular acceleration, and the active weight moving acceleration. Estimate the step resistance torque. In this case, not only the driving wheel rotation angular acceleration indicating the rotation state of the driving wheel 12, but also the vehicle body inclination angular acceleration and the active weight portion moving acceleration indicating the change in the vehicle body posture are considered. That is, the change in the vehicle body posture, which is a characteristic element of a vehicle using the posture control of the inverted pendulum, that is, the so-called inverted vehicle is taken into consideration.

  Conventionally, since the step resistance torque is estimated based on the drive torque and the driving wheel rotation angular acceleration, a large error may occur in the estimated value of the step resistance torque especially when the posture of the vehicle body is changing. . However, in the present embodiment, the step resistance torque is estimated in consideration of the vehicle body inclination angle acceleration indicating the change in the posture of the vehicle body and the active weight portion moving acceleration, so that a large error does not occur and the step is highly accurate. The resistance torque can be estimated.

  Generally, in an inverted type vehicle, the center of gravity of the vehicle body moves back and forth relative to the drive wheels, so that the center of gravity of the vehicle may move back and forth even when the drive wheels are stopped. Therefore, in order to estimate the step resistance torque with high accuracy from the acceleration of the center of gravity and the driving force or the driving torque, it is necessary to consider such an influence. In a general inverted type vehicle, the weight ratio of the vehicle body with respect to the entire vehicle is high, and the change in posture during the step-up / down operation is large, so such an effect becomes large.

  In the present embodiment, the step resistance torque that changes during the step-up / down operation is always estimated. For example, if a constant drive torque is applied to the drive wheels 12 during the step-up / down operation, the vehicle 10 may be unnecessarily accelerated / decelerated immediately before the end of the lift. This is because, for example, when riding on a step, the step resistance torque decreases as the vehicle 10 climbs the step. Therefore, in this embodiment, the step resistance torque that changes with the step elevation state is estimated in real time, and the value is constantly updated so that the step elevation torque suitable for the step elevation operation is always applied. It has become.

  Note that the high frequency component of the estimated value can be removed by applying a low pass filter to the estimated value of the step resistance torque. In this case, a time delay occurs in the estimation, but the vibration caused by the high frequency component can be suppressed.

  In the present embodiment, only the driving torque and the inertial force are considered, but the rolling resistance of the driving wheel 12, the viscous resistance due to the friction of the rotating shaft, the air resistance acting on the vehicle 10, etc. are secondary. It may be considered as an effect.

  In the present embodiment, a linear model related to the rotational motion of the drive wheel 12 is used. However, a more accurate nonlinear model may be used, or a model for vehicle body tilting motion or active weight portion translational motion. May be used. For nonlinear models, functions can also be applied in the form of maps.

  Further, in order to simplify the calculation, it is not necessary to consider the change in the body posture.

  Next, the target travel state determination process will be described.

  FIG. 8 is a flowchart showing the operation of the target travel state determination process in the first embodiment of the present invention.

  In the determination process of the target travel state, the main control ECU 21 first acquires a steering operation amount (step S3-1). In this case, the occupant 15 acquires the operation amount of the joystick 31 that is operated to input a travel command such as acceleration, deceleration, turning, on-site rotation, stop, and braking of the vehicle 10.

  Subsequently, the main control ECU 21 determines a target value for vehicle acceleration based on the acquired operation amount of the joystick 31 (step S3-2). For example, a value proportional to the amount of operation of the joystick 31 in the front-rear direction is set as a target value for vehicle acceleration.

Subsequently, the main control ECU 21 calculates the target value of the drive wheel rotational angular velocity from the determined target value of the vehicle acceleration (step S3-3). For example, by integrating the target value of the vehicle acceleration time, a value obtained by dividing the driving wheel contact radius R _W and the target value of the drive wheel rotation angular velocity.

  Next, the target vehicle body posture determination process will be described.

  FIG. 9 is a graph showing changes in the target value of the active weight portion position and the target value of the vehicle body tilt angle in the first embodiment of the present invention, and FIG. 10 shows the target vehicle body posture in the first embodiment of the present invention. It is a flowchart which shows the operation | movement of a determination process.

In the target body posture determination process, the main control ECU 21 first determines the target value of the active weight portion position and the target value of the vehicle body tilt angle (step S4-1). In this case, based on the target value of the vehicle acceleration determined by the target travel state determination process and the step lift torque τ _C acquired by the step lift torque determination process, the following expressions (2) and (3) are used. Then, the target value of the active weight portion position and the target value of the vehicle body inclination angle are determined.

  Subsequently, the main control ECU 21 calculates the remaining target value (step S4-2). That is, the target values of the drive wheel rotation angle, the vehicle body inclination angular velocity, and the active weight portion moving speed are calculated by time differentiation or time integration of each target value.

Thus, in the present embodiment, not only the inertial force and drive motor reaction torque acting on the vehicle body in accordance with the vehicle acceleration, but also acting on the vehicle body with the step lifting torque τ _C corresponding to the step resistance torque τ _D. The target value of the vehicle body posture, that is, the target value of the active weight portion position and the target value of the vehicle body tilt angle are determined in consideration of the counter torque.

  At this time, the center of gravity of the vehicle body is moved so that the torque that acts on the vehicle body to tilt the vehicle body, that is, the vehicle body tilt torque is canceled out by the action of gravity. For example, when the vehicle 10 climbs a step, the riding section 14 is moved forward, or the vehicle body is further tilted forward. Further, when the vehicle 10 moves down the step, the riding section 14 is moved rearward, or the vehicle body is further tilted rearward.

  In the present embodiment, as shown in FIG. 9, first, the riding section 14 is moved without tilting the vehicle body, and when the riding section 14 reaches the active weight movement limit, the tilting of the vehicle body is started. . For this reason, the vehicle body does not tilt forward and backward with respect to fine acceleration / deceleration, so that the ride comfort for the occupant 15 is improved. Further, if the level difference is not particularly high, the vehicle body is kept upright even on the level difference, so that it is easy to secure the field of view for the occupant 15. In addition, if the level difference is not particularly high, the vehicle body does not greatly tilt even on the level difference, so that a part of the vehicle body is prevented from contacting the road surface.

  In the present embodiment, it is assumed that the active weight part movement limit is equal between the front and the rear, but when the front and rear are different, the inclination of the vehicle body is changed according to each limit. The presence or absence may be switched. For example, when the braking performance is set higher than the acceleration performance, it is necessary to set the rear active weight portion movement limit farther than the front limit.

  In this embodiment, when the acceleration is low or the level difference is low, only the movement of the riding section 14 is used, but some or all of the vehicle body tilt torque may be handled by the vehicle body tilt. Good. By tilting the vehicle body, the front-rear inertial force acting on the occupant 15 can be reduced.

  Furthermore, in the present embodiment, an expression based on a linearized dynamic model is used, but an expression based on a more accurate nonlinear model or a model considering viscous resistance may be used. Note that if the equation is nonlinear, the function can be applied in the form of a map.

  Next, the actuator output determination process will be described.

  FIG. 11 is a flowchart showing the operation of the actuator output determination process in the first embodiment of the present invention.

In the actuator output determination process, the main control ECU 21 first determines the feedforward output of each actuator (step S5-1). In this case, the feedforward output of the drive motor 52 is determined by the following equation (4) from each target value and the step lifting torque τ _C, and the feedforward of the active weight motor 62 is determined by the following equation (5). Determine the output.

Thus, by automatically adding the step lifting torque τ _C according to the step resistance torque τ _D , that is, by correcting the driving torque according to the step resistance torque τ _D , when the step is raised or lowered Can also provide the same handling feeling as the flat ground. That is, it is possible to get on and off the level difference by the same steering operation as that on the flat ground. In addition, the vehicle 10 is not unnecessarily accelerated or decelerated when the level difference is raised or lowered with respect to a certain steering operation of the joystick 31.

  Thus, in the present embodiment, more accurate control is realized by theoretically giving a feedforward output.

  Note that the feedforward output can be omitted as necessary. In this case, the feedback control indirectly gives a value close to the feedforward output with a steady deviation. Further, the steady deviation can be reduced by applying an integral gain.

  Subsequently, the main control ECU 21 determines the feedback output of each actuator (step S5-2). In this case, the feedback output of the drive motor 52 is determined by the following equation (6) from the deviation between each target value and the actual state quantity, and the feedback output of the active weight unit motor 62 by the following equation (7). To decide.

Note that nonlinear feedback control such as sliding mode control can also be introduced. As simpler control, some of the feedback gains excluding K _W2 , K _W3, and K _S5 may be set to zero. Further, an integral gain may be introduced in order to eliminate the steady deviation.

  Finally, the main control ECU 21 gives a command value to each element control system (step S5-3). In this case, the main control ECU 21 transmits the sum of the feedforward output and the feedback output determined as described above to the drive wheel control ECU 22 and the active weight part control ECU 23 as the drive torque command value and the active weight part thrust command value. .

As described above, in the present embodiment, the step resistance torque τ _D is estimated by the observer, the step lifting torque τ _C is applied, and the riding section 14 is moved in the upper direction of the step. Therefore, the vehicle body can be held upright even on the level difference, and the level difference can be raised and lowered. In addition, an apparatus for measuring a step is not required, and the system configuration can be simplified and the cost can be reduced.

Furthermore, since in view of the vehicle body inclination angle theta ₁ and active weight portion position lambda _S indicates the attitude of the vehicle body is estimated the step lifting torque tau _C, without a large error occurs, the step lifting torque tau _C with extremely high precision Can be estimated.

  Note that this embodiment is effective not only when climbing a step, but also when descending a step. The acceleration of the vehicle when the step is lowered is suppressed by applying the step lifting torque, and the vehicle body is held upright by moving the riding portion 14 backward. The same applies to other embodiments described below.

  Next, a second embodiment of the present invention will be described. In addition, about the thing which has the same structure as 1st Embodiment, the description is abbreviate | omitted by providing the same code | symbol. The description of the same operation and the same effect as those of the first embodiment is also omitted.

  FIG. 12 is a block diagram showing the configuration of the vehicle control system in the second embodiment of the present invention, and FIG. 13 is a schematic diagram showing the operation in raising and lowering the step of the vehicle in the second embodiment of the present invention. .

  In the first embodiment, the riding part 14 is attached so as to be able to translate relative to the main body part 11 in the front-rear direction of the vehicle 10 and functions as an active weight part. In this case, a moving mechanism including the active weight motor 62 is disposed, and thereby the riding section 14 is translated, so that the control system is complicated as the structure becomes complicated and the cost and weight increase. Further, the first embodiment cannot be applied to an inverted vehicle that does not have a moving mechanism for moving the riding section 14.

  Therefore, in the present embodiment, a moving mechanism for moving the riding section 14 is omitted. Also, as shown in FIG. 12, the active weight part control system 60 is omitted from the control system, and the active weight part control ECU 23, the active weight part sensor 61, and the active weight part motor 62 are omitted. Since the configuration of other points is the same as that of the first embodiment, description thereof is omitted.

  In the present embodiment, as shown in FIG. 13, when raising and lowering the step, the driving torque applied to the drive wheel 12 for raising and lowering the step, that is, the reaction to the step raising and lowering torque is applied to the vehicle body. By tilting the vehicle body in the upper direction of the step by an angle corresponding to the step lifting torque with respect to the vehicle body tilting torque acting as an anti-torque, the vehicle body tilting torque is canceled by the action of gravity to maintain a balance.

  In addition, as explained in the section of “Background Art”, for example, when a required driving torque is applied to the driving wheel when riding on a step, the reaction acts on the vehicle body, so that the vehicle body is in a direction opposite to the step, that is, It will be greatly inclined in the lower direction of the step. On the other hand, if the posture of the vehicle body is to be maintained upright, the necessary driving torque cannot be applied to the driving wheels, so that it is impossible to ride on the step. In addition, the same phenomenon occurs when getting down the step, and the vehicle body tilts forward.

  In contrast, in the present embodiment, the vehicle body is intentionally tilted in the upper direction of the step by an angle suitable for the height of the step, so that a stable body posture can be maintained even when the step is raised or lowered. It is possible to travel safely and comfortably in places with steps.

  Next, details of the traveling and posture control processing in the present embodiment will be described. The outline of the travel and attitude control process and the determination process of the target travel state are the same as those in the first embodiment, so the description is omitted, the state quantity acquisition process, the step elevation torque determination process, Only the target vehicle body attitude determination process and the actuator output determination process will be described. First, the state quantity acquisition process will be described.

FIG. 14 is a flowchart showing the operation of the state quantity acquisition process in the second embodiment of the present invention.

  Next, the step elevation torque determination process will be described.

  FIG. 15 is a flowchart showing the operation of the step elevation torque determination process in the second embodiment of the present invention.

In the step elevation torque determination process, the main control ECU 21 estimates the step resistance torque τ _D (step S2-11). In this case, based on each state quantity acquired in the state quantity acquisition process and the output of each actuator determined in the actuator output determination process in the previous run (previous time step) travel and posture control process, The step resistance torque τ _D is estimated from equation (8).

Subsequently, the main control ECU 21 determines the step elevation torque τ _C (step S2-12). In this case, the estimated value of the step resistance torque τ _D is set as the value of the step lifting torque τ _C. That is, τ _C = τ _D.

  Thus, in the present embodiment, the step resistance torque is estimated based on the driving torque output from the driving motor 52, the driving wheel rotation angular acceleration and the vehicle body inclination angular acceleration as the state quantities. In this case, not only the driving wheel rotation angular acceleration indicating the rotation state of the driving wheel 12 but also the vehicle body inclination angular acceleration indicating the change in the vehicle body posture is considered. That is, the change in the vehicle body posture, which is a characteristic element of a vehicle using the posture control of the inverted pendulum, that is, the so-called inverted vehicle is taken into consideration.

  Conventionally, since the step resistance torque is estimated based on the driving torque and the driving wheel rotation angular acceleration, a large error may occur in the estimated value of the step resistance torque especially when the posture of the vehicle body changes greatly. However, in the present embodiment, the step resistance torque is estimated in consideration of the vehicle body inclination angle acceleration indicating the change in the posture of the vehicle body, so that a large error does not occur and the step resistance torque can be estimated with high accuracy. it can.

  In the present embodiment, the step resistance torque that changes during the step-up / down operation is always estimated. For example, if a constant drive torque is applied to the drive wheels 12 during the step-up / down operation, the vehicle 10 may be unnecessarily accelerated / decelerated immediately before the end of the lift. This is because, for example, when riding on a step, the step resistance torque decreases as the vehicle 10 climbs the step. Therefore, in this embodiment, the step resistance torque that changes with the step elevation state is estimated in real time, and the value is constantly updated so that the step elevation torque suitable for the step elevation operation is always applied. It has become.

  As in the first embodiment, a high-frequency component of the estimated value can be removed by applying a low-pass filter to the estimated value of the step resistance torque. In this case, a time delay occurs in the estimation, but the vibration caused by the high frequency component can be suppressed.

  In the present embodiment, only the inertial force is considered, but the rolling resistance of the drive wheel 12, the viscous resistance due to the friction of the rotating shaft, the air resistance acting on the vehicle 10, etc. are secondary effects. You may consider it.

  Further, a more accurate nonlinear model may be used, or a model for vehicle body tilt motion may be used. For nonlinear models, functions can also be applied in the form of maps.

  Further, in order to simplify the calculation, it is not necessary to consider the change in the body posture.

  Next, the target vehicle body posture determination process will be described.

  FIG. 16 is a flowchart showing the operation of target body posture determination processing in the second embodiment of the present invention.

In the determination process of the target vehicle body posture, the main control ECU 21 first determines a target value of the vehicle body inclination angle (step S4-11). In this case, based on the target value of the vehicle acceleration determined by the target travel state determination process and the step lift torque τ _C acquired by the step lift torque determination process, the vehicle body inclination angle is expressed by the following equation (9). Determine the target value.

  Subsequently, the main control ECU 21 calculates the remaining target value (step S4-12). That is, the target values of the drive wheel rotation angle and the vehicle body inclination angular velocity are calculated by time differentiation or time integration of each target value.

Thus, in the present embodiment, not only the inertial force and drive motor reaction torque acting on the vehicle body in accordance with the vehicle acceleration, but also acting on the vehicle body with the step lifting torque τ _C corresponding to the step resistance torque τ _D. The target value of the vehicle body posture, that is, the target value of the vehicle body tilt angle is determined in consideration of the counter torque.

  At this time, the center of gravity of the vehicle body is moved so as to cancel the vehicle body tilt torque by the action of gravity. For example, when the vehicle 10 accelerates and climbs a step, the vehicle body is tilted forward. Further, when the vehicle 10 decelerates and descends a step, the vehicle body is tilted backward.

  In the present embodiment, an expression based on a linearized dynamic model is used, but an expression based on a more accurate nonlinear model or a model considering viscous resistance may be used. Note that if the equation is nonlinear, the function can be applied in the form of a map.

  Next, the actuator output determination process will be described.

  FIG. 17 is a flowchart showing the operation of the actuator output determination process in the second embodiment of the present invention.

In the actuator output determination process, the main control ECU 21 first determines the feedforward output of the actuator (step S5-11). In this case, the feedforward output of the drive motor 52 is determined from the target value and the step elevation torque τ _{C according} to the equation (4) described in the first embodiment.

As shown in the above equation (4), by automatically adding a step lifting torque τ _C corresponding to the step resistance torque τ _D , the same control feeling as on the flat ground is provided even when the step is raised or lowered can do. That is, it is possible to get on and off the level difference by the same steering operation as that on the flat ground. In addition, the vehicle 10 is not unnecessarily accelerated or decelerated when the level difference is raised or lowered with respect to a certain steering operation of the joystick 31.

  In the present embodiment, more accurate control is realized by theoretically giving a feedforward output, but the feedforward output can be omitted if necessary. In this case, the feedback control indirectly gives a value close to the feedforward output with a steady deviation. Further, the steady deviation can be reduced by applying an integral gain.

  Subsequently, the main control ECU 21 determines the feedback output of the actuator (step S5-12). In this case, the feedback output of the drive motor 52 is determined by the following equation (10) from the deviation between each target value and the actual state quantity.

Note that nonlinear feedback control such as sliding mode control can also be introduced. As a simpler control, some of the feedback gains excluding K _W2 and K _W3 may be set to zero. Further, an integral gain may be introduced in order to eliminate the steady deviation.

  Finally, the main control ECU 21 gives a command value to the element control system (step S5-13). In this case, the main control ECU 21 transmits the sum of the feedforward output and the feedback output determined as described above to the drive wheel control ECU 22 as a drive torque command value.

  As described above, in the present embodiment, the vehicle body can be tilted in the upper direction of the step to maintain the balance when the step is raised or lowered. Therefore, it can be applied to an inverted vehicle that does not have a moving mechanism for moving the riding section 14, and the structure and the control system are simplified, so that stable and low-level ingress and egress can be achieved even on an inexpensive and lightweight inverted vehicle. Can be realized.

  Next, a third embodiment of the present invention will be described. In addition, about the thing which has the same structure as 1st and 2nd embodiment, the description is abbreviate | omitted by providing the same code | symbol. Also, the description of the same operations and effects as those of the first and second embodiments is omitted.

  FIG. 18 is a schematic diagram showing the configuration of the vehicle according to the third embodiment of the present invention, showing a state where a step is detected before the step, and FIG. 19 is a vehicle according to the third embodiment of the present invention. FIG. 20 is a block diagram showing a configuration of a vehicle control system according to a third embodiment of the present invention. 18, (b) is an enlarged view of the main part of (a), and (a) to (c) in FIG. 19 show a series of operations.

  If a constant driving torque is applied to the drive wheels 12 during the step-up / down operation, the vehicle 10 may unnecessarily accelerate / decelerate immediately before the end of the step-up / down operation. This is because, for example, when riding on a step, the step resistance torque decreases as the vehicle 10 climbs the step.

  Therefore, in the present embodiment, a step in the traveling direction of the vehicle 10 is detected by a sensor, and the position and height of the step measured by the sensor and the rotation angle of the driving wheel corresponding to the raised / lowered state of the step are determined. The step lifting torque is changed.

  Therefore, in the present embodiment, the vehicle 10 includes a distance sensor 71 as a step measurement sensor, as shown in FIG. The distance sensor 71 uses, for example, laser light, but may be any type of sensor. In the example shown in FIG. 18, two distance sensors 71 are disposed on the lower surface of the riding section 14 so as to be separated from each other in the front-rear direction, and each measures the distance from the lower surface to the front and rear road surfaces. And the level | step difference of a road surface can be detected from the change of the measured value of each distance sensor 71, and the position and height of the detected level | step difference can be acquired. Desirably, one distance sensor 71 is disposed in front of a portion of the driving wheel 12 that contacts the road surface, and the other distance sensor 71 is disposed rearward of a portion of the driving wheel 12 that contacts the road surface. Is done. Thus, since the two distance sensors 71 measure the distance to the road surface at a position away from the contact point of the drive wheel 12, the step difference between the front and rear of the vehicle 10 can be detected.

  Moreover, the vehicle 10 has a level difference measurement system 70 including a distance sensor 71 as shown in FIG. Then, the distance sensor 71 detects the ground distance as the distance to the road surface at two points on the front and rear sides, and transmits it to the main control ECU 21.

  Thus, for example, when riding on a step, as shown in FIG. 19, the amount of movement of the riding section 14, the driving torque for riding on the step, etc. are changed as the vehicle 10 rises, thereby stabilizing the vehicle body posture. And travel control can be performed.

  Next, details of the traveling and posture control processing in the present embodiment will be described. The outline of the travel and attitude control process, the state quantity acquisition process, the target travel state determination process, the target vehicle body attitude determination process, and the actuator output determination process are the same as those in the first embodiment. The description will be omitted, and only the process for determining the step lifting torque will be described.

  FIG. 21 is a diagram showing a geometric condition when measuring an ascending step according to the third embodiment of the present invention, and FIG. 22 is a step ascending / descending resistivity of the ascending step according to the third embodiment of the present invention. FIG. 23 is a diagram showing a geometric condition when measuring a down step in the third embodiment of the present invention, and FIG. 24 is a down view in the third embodiment of the present invention. The figure which shows the change of the level | step difference raising / lowering resistivity of a level | step difference, FIG. 25: is a flowchart which shows the operation | movement of the determination process of the level | step difference raising / lowering torque in the 3rd Embodiment of this invention.

  In the step elevation torque determination process, the main control ECU 21 first acquires the measurement value of the distance sensor 71 (step S2-21). In this case, the measured value of the ground distance is acquired from the two front and rear distance sensors 71.

Subsequently, the main control ECU 21 determines the position and height of the step (step S2-22). In this case, determined by the time history of the ground distance obtained from the distance sensors 71, the vehicle body inclination angle theta _1, the position of the riding section 14, i.e., based on the active weight portion position lambda _S, the position and height of the step To do.

Subsequently, the main control ECU 21 determines the step resistance torque τ _D (step S2-23). In this case, the step resistance torque τ _D is calculated by the following equation (11).
τ _D = ξτ _{D, Max} (11)
Here, τ _{D, Max} is the maximum step resistance torque, and ξ is the step elevation resistance.

As shown in FIG. 21, when the step is ascending, that is, ascending, the maximum step resistance torque τ _{D, Max} and the step elevation resistivity ξ are expressed by the following equations (12) and (13). In FIG. 21, X is the distance to the step when the step is detected, and H is the height of the step. In the case of ascending stage, H is zero or more.

In addition, η ₀ is a virtual climbing angle and corresponds to a driving wheel rotation angle necessary for climbing a step. Θ _{W, S} is the driving wheel rotation angle when the driving wheel 12 contacts the step, and θ _{W, 0} is the driving wheel rotation angle when the step is detected. Further, Δθ _W is the driving wheel rotation angle (relative driving wheel rotation angle) after the step contact, and the value becomes zero when the driving wheel 12 contacts the step.

Then, the value of the step resistance torque τ _D changes as shown in FIG. That is, the maximum value τ _{D, Max} is reached when the drive wheel 12 contacts the step, gradually decreases during the ascending step, and reaches the minimum value of zero when the ascending step is finished.

As shown in FIG. 23, when the step is down, that is, when the step is down, the maximum step resistance torque τ _{D, Max} and the step up / down resistivity ξ are expressed by the following equations (14) and (15). Is done. In FIG. 23, X is the distance to the step when the step is detected, and H is the height of the step. In the case of descending, H is less than zero, that is, minus.

Then, the value of the step resistance torque τ _D changes as shown in FIG. That is, the minimum value is zero when the drive wheel 12 contacts the step, gradually decreases during the descending step, and reaches the maximum value τ _{D, Max} immediately before the end of the descending step.

Finally, the main control ECU 21 determines the step elevation torque τ _C (step S2-24). In this case, the estimated value of the step resistance torque τ _D is set as the value of the step lifting torque τ _C. That is, τ _C = τ _D.

In this way, in the step elevation torque determination process, the step resistance torque τ _D is changed in accordance with the step height H. That is, the value of the step resistance torque τ _D is increased as the value of the step height H is increased.

Further, the magnitude of the step resistance torque τ _D is changed in accordance with the step elevation state of the vehicle 10. That is, the elevation state of the vehicle 10 is estimated from the drive wheel rotation angle θ _W and the value of the step elevation resistivity ξ is changed. Thereby, it is possible to cope with a speed change of the vehicle 10.

Specifically, when climbing a step, that is, when the step height H is zero or more, the step resistance torque τ _D (step elevation resistivity ξ) is decreased as the drive wheel rotation angle θ _W increases. This is because the driving torque required to support the vehicle 10 decreases as the level difference is increased.

On the other hand, when descending the step, that is, when the height H of the step is less than zero, the step resistance torque τ _D (step elevation resistivity ξ) is increased as the drive wheel rotation angle θ _W increases. This is because the driving torque required to support the vehicle 10 increases as the level difference is lowered.

  Thereby, the driving | running | working state of the vehicle 10 at the time of level | step difference raising / lowering can be controlled stably.

  In the present embodiment, only the case where the vehicle 10 moves forward and enters the step located in front of the vehicle 10 has been described. However, the same applies to the case where the vehicle 10 moves backward and enters the step located behind the vehicle 10. Control can be implemented.

  In the present embodiment, the case where the distance sensor 71 is not used during the step-up / down operation is described. However, in order to grasp the step-up / down state of the vehicle 10 more accurately, the measurement value of the distance sensor 71 is used. You can also Thereby, stable control can be performed even if the drive wheel 12 slips.

  Further, in the present embodiment, the case where a discontinuous function is used in the determination formula of the step elevation resistivity ξ has been described, but a function in which the discontinuous portion is continuously corrected can also be used. In addition, in order to prevent control chattering or vehicle operation hunting at discontinuous portions, hysteresis control (for example, control in which two threshold values are set and the threshold value is changed according to the rotation direction of the drive wheels 12) is introduced. Also good.

  Furthermore, in the present embodiment, the case of using a determinant based on a non-linear dynamic model has been described. However, for the sake of simplicity, a linear approximation formula may be used. Further, a more advanced determination formula that considers deformation of the drive wheel 12, rolling friction, slip conditions, and the like may be used.

As described above, in the present embodiment, the step in the traveling direction of the vehicle 10 is detected by the distance sensor 71, and according to the position and height H of the step measured by the distance sensor 71 and the driving wheel rotation angle θ _W. The value of the step elevation torque τ _C is changed. Therefore, the inverted posture of the vehicle body can be kept stable even when the step is raised or lowered. Thereby, the vehicle 10 can drive | work safely and comfortably also in the place with a level | step difference.

  In the present embodiment, the case where a step is detected and the position and height H of the step are measured by the two distance sensors 71 has been described. However, other devices and methods can be used. For example, the detection of the step and the position and height H of the step may be measured by acquiring an image of the traveling direction of the vehicle 10 with a camera and analyzing the acquired image. Further, for example, based on a vehicle position acquisition system that acquires the position of the vehicle 10 using GPS (Global Positioning System), and map data that includes information on the road surface and the level difference, the level difference that exists around the vehicle 10 is determined. Information may be acquired.

  Next, a fourth embodiment of the present invention will be described. In addition, about the thing which has the same structure as the 1st-3rd embodiment, the description is abbreviate | omitted by providing the same code | symbol. Explanation of the same operations and effects as those of the first to third embodiments is also omitted.

  FIG. 26 is a diagram showing the geometric relationship between the vehicle body and the step when riding on the step in the fourth embodiment of the present invention, and FIG. 27 shows the operation of the target state determination process in the fourth embodiment of the present invention. It is a flowchart to show.

  When the vehicle 10 goes up and down a high step, if the step is too high to go up, the occupant 15 uses the joystick 31 to move up and down the step while rapidly accelerating or down the step while rapidly decelerating. When the command is given, the vehicle body may be greatly inclined, or the vehicle 10 may be accelerated or decelerated so that the occupant 15 feels unnatural.

  Such a phenomenon occurs when the vehicle acceleration target value requested by the occupant 15 with the joystick 31 exceeds a limit, that is, an unrealizable value, and the state of the vehicle 10 assumed and the actual vehicle 10. This occurs when the vehicle running state and the vehicle body posture control suitable for the actual state are not executed.

  Further, the limit value of the vehicle acceleration is determined by the limit of the vehicle running performance and the limit of the vehicle body attitude control, and each limit changes according to the step. The limit of the vehicle running performance corresponds to the limit value of the driving torque necessary for raising or lowering the step or accelerating / decelerating, and the limit value of the vehicle acceleration based on the limit of the vehicle running performance changes according to the step resistance torque. The limit of the vehicle body posture control is that the vehicle body posture is controlled against the counter torque that acts on the vehicle body along with the drive torque required for step up / down or acceleration / deceleration, and the inertial force that acts on the vehicle body along with acceleration / deceleration. It corresponds to the limit of the vehicle body center of gravity movement amount (vehicle body inclination angle and active weight portion movement amount) necessary for holding, and the vehicle acceleration limit value based on the vehicle body attitude control limit depends on the step resistance torque and step height Change.

  For example, when going up a high step, when the maximum torque of the drive motor 52 is lower than the large step resistance torque, the vehicle 10 decelerates even if the drive motor 52 generates the maximum torque. That is, the vehicle acceleration is limited to a certain negative value as the upper limit due to the limit of the vehicle running performance. In addition, when a step lifting torque that opposes a large step resistance torque is generated, it is necessary to largely move the center of gravity of the vehicle body forward in order to counteract the reaction torque that acts on the vehicle body as a reaction, The amount of forward movement has a limit on the vehicle body structure, and the forward inclination of the vehicle body is limited in order to avoid contact with the road surface. In particular, when the level difference is high, it is necessary to avoid contact with the level difference, so that the vehicle body inclination is more severely limited. Therefore, it is necessary to counter the counter-torque not only by the gravity torque due to the movement of the center of gravity of the vehicle body but also by decelerating the vehicle 10 and by the inertial force accompanying the deceleration. That is, the vehicle acceleration is limited to a certain negative value as the upper limit due to the limit of the vehicle body posture control.

  Therefore, in order to realize stable vehicle operation even when moving up and down a high step, the limit value of vehicle acceleration that changes in a complicated manner due to the step is appropriately evaluated, and the target value of vehicle acceleration is appropriately limited by the limit value. There is a need to.

  Therefore, in the present embodiment, during the elevation of the step, the limit of the vehicle running performance and the limit of the vehicle body posture control are evaluated based on the step resistance torque, and the limit value of the vehicle acceleration is determined according to them, and the limit value is determined. To limit the target value of vehicle acceleration. When evaluating the limit of the vehicle body posture control, a change in the vehicle body tilt angle variable region due to the presence of a step is taken into consideration.

  Thereby, even when the vehicle 10 enters a high step, stable vehicle operation can always be maintained, and safe and comfortable travel for the occupant 15 can be realized.

  Next, details of the traveling and posture control processing in the present embodiment will be described. The outline of the travel and posture control processing, the state quantity acquisition processing, the step elevation torque determination processing, the target vehicle body posture determination processing, and the actuator output determination processing are the same as those in the first embodiment. The description will be omitted, and only the target running state determination process will be described.

  First, the main control ECU 21 acquires a steering operation amount (step S3-31). In this case, the occupant 15 acquires the operation amount of the joystick 31 that is operated to input a travel command such as acceleration, deceleration, turning, on-site rotation, stop, and braking of the vehicle 10.

Subsequently, the main control ECU 21 determines a target value of vehicle acceleration based on the obtained operation amount of the joystick 31 and the step resistance torque (step S3-32). In this case, the vehicle acceleration target value α ^* is determined by the following equation (16).

Α _Max and α _Min are the upper limit value and the lower limit value of the vehicle acceleration, respectively, and are determined by the following equations (17) and (18).

  On the other hand, the conditional expressions of the second expression and the third expression in the expressions (17) and (18) are such that there is no overlapping range in the two allowable ranges, that is, the two stable controls cannot be compatible. Means. When this condition is satisfied, the limit of the vehicle body attitude control is emphasized, and the optimum value is within the allowable range based on the limit of the vehicle body attitude control and closest to the allowable range based on the vehicle driving performance limit. And the vehicle acceleration target value is automatically set to the optimum value by setting both the upper limit value and the lower limit value of the vehicle acceleration to their optimum values.

The upper limit value α _{Max, W} and the lower limit value α _{Min, W} of the vehicle acceleration based on the limit of the vehicle running performance are determined by the following equations (19) and (20), respectively.

Note that the second term on the right side in the equations (19) and (20) represents the effect of the step on the vehicle running performance. When the step resistance torque τ _D is positive, that is, when climbing the front step, both the upper limit value α _{Max, W} and the lower limit value α _{Min, W} of the vehicle acceleration are lowered according to the magnitude of the step resistance torque τ _D. When the step resistance torque τ _D is negative, that is, when going down the front step, the upper limit value α _{Max, W} and the lower limit value α _{Min, W} of the vehicle acceleration are set according to the magnitude of the step resistance torque τ _D. Make both high.

Δθ _{1, f} and Δθ _{1, b} are the front vehicle body tilt angle limit amount and the rear vehicle body tilt angle limit amount due to the step, respectively, and the maximum vehicle body tilt angle on the road surface without the step and the upper side when the step is raised and lowered. It is defined as the difference from the vehicle body inclination angle at which the lower end of the vehicle body contacts the surface. That is, how much the vehicle body inclination is suppressed indicates how much the vehicle body does not come into contact with the step, and the reduction amount of the vehicle body inclination angle. These values are determined by geometric conditions, and are expressed as, for example, the following equations (25) and (26).

Here, h is the substantial step height, and represents the distance between the bottom surface of the drive wheel (a plane parallel to the road surface and in contact with the lower side of the drive wheel) and the top surface of the step in the middle of raising or lowering the step. Further, l is the distance from the vehicle body tilt center to the road surface contact point, and the distance from the axle that is the vehicle body tilt center to the point on the vehicle body surface that first contacts the step when the vehicle body actually tilts (parallel to the axle). (Except for components in various directions). In the example shown in FIG. 26, the riding part 14 of the vehicle 10 includes a step part 14d on which the foot of the occupant 15 is placed, and the lower end of the step part 14d corresponds to a road surface contact point. Note that h can be estimated from the value of the step resistance torque and is expressed by the following equation (27).
h = R _W (1−cos η) (27)
Here, η is a virtual uphill angle and is expressed by the following equation (28).

Finally, the main control ECU 21 calculates the target value of the drive wheel rotational angular velocity from the determined target value of the vehicle acceleration (step S3-33). For example, by integrating the target value of the vehicle acceleration time, a value obtained by dividing the driving wheel contact radius R _W and the target value of the drive wheel rotation angular velocity.

  Here, only the case where the vehicle moves forward and enters the step located in front of the vehicle 10 has been described, but the same control is performed also when the vehicle moves backward and enters the step located behind the vehicle 10. be able to.

  In this way, when the target value of the vehicle acceleration and the target value of the drive wheel rotation angular velocity are determined in the target travel state determination process, the target vehicle acceleration target is determined in the target body posture determination process to be executed next. The target value of the vehicle body posture corresponding to the value, that is, the target value of the active weight portion position and the target value of the vehicle body tilt angle are determined. Then, in the actuator output determination process to be executed next, the actuators necessary for realizing each target value determined in the target travel state determination process and the target vehicle body attitude determination process, that is, the drive motor 52 and the active The output of the weight part motor 62 is determined.

  According to the above method, even if the vehicle 10 is in any stepped up / down state, the target value of the vehicle acceleration is appropriately limited by the limit value of the vehicle acceleration considering the effect of the step, so Can be kept stable. For example, even when the occupant 15 instructs to climb a level difference, the level difference is very high and cannot be fully climbed, so that stable vehicle operation can be maintained.

  Hereinafter, as a specific example of vehicle operation according to the present embodiment, a case will be described in which the vehicle 10 enters a high step while gradually accelerating, but cannot reach the step due to a limit of driving torque.

  FIG. 28 is a diagram showing each state quantity during operation in which the step cannot be fully climbed in the fourth embodiment of the present invention. Moreover, FIG. 29 is a figure which shows the level | step difference raising / lowering state and vehicle body attitude | position at the time of the operation | movement which could not go up the level | step difference in the 4th Embodiment of this invention. In FIG. 28, (a) shows the step resistance torque, (b) shows the target value of vehicle acceleration, (c) shows the driving wheel rotation angular velocity, and (d) shows the target value of the active weight part position. In FIG. 29, (a) to (c) show a series of operations.

In this operation example, the vehicle 10 moves forward and enters the step, starts climbing the step at time t = t ₁ , and reaches the highest point at time t = t ₂ , but further advances due to the limit of the driving torque. The operation from the start of descent without being able to be made until reaching the lower stage again at time t = t ₃ is shown. In this operation example, the influence of the inertial force due to deceleration on the vehicle body is smaller than the influence of the counter torque of the drive torque on the vehicle body, and the required movement amount of the vehicle body center of gravity is The case where it can achieve only by movement of an active weight part, without inclining is assumed.

Before the driving wheel of the vehicle 10 comes into contact with the step (t <t ₁ ), the occupant 15 gives a constant joystick input amount, whereby a constant vehicle acceleration target value α ^* = as shown in FIG. α _d ^* is set. Then, the driving torque is applied so as to realize the target state, and as shown in FIG. 28 (c), the vehicle 10 is accelerated at a constant acceleration. At the same time, as shown in FIG. 28 (d), by appropriately setting the target value of the active weight part position according to the target value of the vehicle acceleration, the active weight part moves forward the inertial force and the counter-torque accompanying acceleration. It can be canceled by the gravitational torque generated by moving to, and a stable vehicle body posture can be maintained.

When the driving wheels of the vehicle 10 come into contact with the step (t = t ₁ ), the step resistance torque increases rapidly as shown in FIG. When the step resistance torque exceeds the maximum driving torque, as shown in FIG. 28 (b), even if the occupant 15 continues to command the vehicle acceleration α _d ^* before the step contact, the vehicle acceleration target value is It is limited by the upper limit α _Max based on the limit of running performance, and α ^* = α _Max <α _d ^* . That is, even if the occupant 15 commands acceleration, the main control ECU 21 sets a negative target value for vehicle acceleration corresponding to deceleration of the vehicle 10. Then, as shown in FIG. 28 (c), the drive torque is generated so as to coincide with the target value of the vehicle acceleration to control the deceleration of the drive wheel, and as shown in FIG. 28 (d), the deceleration is reduced. In accordance with the target vehicle acceleration target value, the target value of the active weight portion position for moving the active weight portion backward is set so as to cancel the inertial force that acts to tilt the vehicle body forward along with the deceleration. . In this way, by setting the realizable vehicle acceleration α _Max instead of the physically unrealizable vehicle acceleration α _d ^* as the target value, it is possible to stabilize the appropriate running state and body posture as in normal running. Control is automatically executed.

After the step contact, as shown in FIGS. 28 (b) and 28 (c), the vehicle 10 decelerates according to the vehicle acceleration target value α ^* = α _Max limited based on the limit of the vehicle running performance. After the vehicle is temporarily stopped (t = t ₂ ), the step is lowered while rotating the driving wheel in the reverse direction. Incidentally, the reason why the step resistance torque gradually decreases immediately after the step contact is that the substantial step height (the remaining height until the vehicle rides) becomes smaller as the vehicle 10 goes up the step.

When the vehicle 10 lands on the lower step of the step again and leaves the step (t = t ₃ ), the vehicle acceleration as shown in FIG. 28 (b) is accompanied by a decrease in the step resistance torque as shown in FIG. 28 (a). The upper limit value α _{Max of} is increased, and the restriction on the target value of vehicle acceleration is relaxed. Then, in accordance with the target value α _d ^* of the positive vehicle acceleration required by the occupant 15 again, the vehicle speed in the backward direction accompanying the descent from the step is reduced, and at the same time, the active weight part is moved forward according to the target value. The target value of the active weight portion position is determined so as to move.

  Thus, even in a complicated step up and down state in which the vehicle 10 goes up the middle of the step and then descends and descends, the traveling state and the vehicle body posture of the vehicle 10 can be stably controlled.

  As another means for realizing such control, for example, there is a means for switching from a control method during normal driving to another special control method when the level difference is high and cannot be ascended. Introduce control means such as misjudgment of availability, uncomfortable feeling given to the driver when switching the control method, complication of the control algorithm and program, occurrence of a phenomenon where switching is repeated intermittently near the threshold for switching the control method There are also many problems caused by the problem.

  On the other hand, in the present embodiment, the traveling state and the vehicle body posture of the vehicle 10 can be stabilized simply by adding an appropriate restriction on the target vehicle acceleration to the control during the normal traveling in any stepped state of the vehicle 10. It is possible to control, and simple and robust control is realized.

  In this way, the main control ECU 21 correctly evaluates the limit value of the vehicle acceleration that changes depending on the step elevation state of the vehicle during the step elevation.

  Specifically, the vehicle acceleration upper limit value and lower limit value are determined based on the step resistance torque. Accordingly, it is possible to set the vehicle acceleration limit value according to the stepped state in consideration of the effect of the step on the vehicle operation.

  Then, the vehicle acceleration limit value is determined in consideration of the vehicle running performance limit and the vehicle body attitude control limit. That is, the vehicle acceleration limit value is obtained for each limit, and the value of the more severe condition among the limit of running performance and the limit of vehicle body posture control is set as the limit value of vehicle acceleration step elevation. Specifically, the vehicle acceleration upper limit value due to the limit of the vehicle running performance is compared with the vehicle acceleration upper limit value due to the limit of the vehicle body posture control, and the lower one is set as the vehicle acceleration upper limit value. Further, the vehicle acceleration lower limit value due to the limit of the vehicle running performance is compared with the vehicle acceleration lower limit value due to the limit of the vehicle body posture control, and the higher one is set as the vehicle acceleration lower limit value. Thereby, the limit value of the vehicle acceleration can be set so that the traveling state and the vehicle body posture during step elevation can be kept stable.

  Furthermore, the vehicle acceleration upper limit value and the lower limit value due to the limit of the vehicle running performance are determined based on the drive torque maximum value and the step resistance torque that are the drive torque limit of the drive motor. Specifically, a value obtained by reducing the vehicle acceleration limit value (reference value) on a level road surface without a step by an amount proportional to the step resistance torque is set as a vehicle acceleration limit value based on the limit of the vehicle running performance. . As a result, it is possible to correctly evaluate the vehicle acceleration limit value when raising or lowering the step, taking into account the change in the travel performance limit due to the step.

  For example, when climbing a step, the higher the step, the more difficult the acceleration and the easier the deceleration. Further, when the height of the step becomes larger than a certain value, the vehicle acceleration upper limit value becomes a negative value. That is, the vehicle decelerates even when the maximum driving torque is applied. And if the vehicle speed at the time of a level | step difference approach is low, a vehicle will start reverse | retreat after stopping as a result of decelerating during climbing on a level | step difference. In this embodiment, by considering such a phenomenon and its mechanism based on the vehicle acceleration and its limit value, it is possible to stably maintain the traveling state and the vehicle body posture in any stepped state. Yes.

  Also, based on the active weight part maximum movement amount and vehicle body inclination angle maximum value that determines the limit of the vehicle body center of gravity movement amount, the step resistance torque related to the vehicle body inclination torque, and the vehicle body inclination angle limit amount due to the step, the vehicle body posture Determine the vehicle acceleration upper and lower limits due to the control limits. Specifically, a value obtained by reducing the vehicle acceleration limit value (reference value) on a horizontal road surface without a step by an amount proportional to the step resistance torque is set as the vehicle acceleration limit value due to the limit of the vehicle body posture control. Accordingly, it is possible to correctly evaluate the vehicle acceleration limit value when raising or lowering the step in consideration of the change in the posture control limit due to the step.

  In addition, the vehicle acceleration limit value due to the limit of the vehicle body posture control is corrected according to the height of the step and the shape of the lower part of the vehicle body. Specifically, when entering a forward ascending step, in order to avoid contact between the step and the vehicle body, the vehicle body inclination angle upper limit value is decreased by the vehicle body inclination angle limit amount, and the vehicle acceleration upper limit value according to the decrease amount. Also reduce. In addition, when entering a forward descending step, in order to avoid contact between the step and the vehicle body, the vehicle body tilt angle lower limit value is decreased by the vehicle body tilt angle limit amount, and the vehicle acceleration lower limit value is also decreased according to the decrease amount. . In the present embodiment, the substantial step height is estimated based on the estimated value of the step resistance torque, and the vehicle body inclination angle reduction amount necessary for avoiding the step contact is obtained based on the estimated step height. Thereby, it can prevent reliably that a vehicle body contacts a level | step difference.

  For example, when climbing a step, if a step lifting torque that counters the step resistance torque is applied, the counter-torque acts on the vehicle body, so it is necessary to move the vehicle body center of gravity forward to cancel it. Since the vehicle body center-of-gravity movement amount is limited by the range of motion of the riding section and the inclination limit where the vehicle body contacts the road surface, the higher the step lift torque, that is, the higher the rising step, the more the vehicle accelerates (acceleration Therefore, the surplus of the allowable amount of movement of the center of gravity of the vehicle body required for canceling the reaction force of the driving torque and the inertial force accompanying the acceleration is reduced. When the height of the step becomes larger than a certain value, the center of gravity of the vehicle body becomes insufficiently moved, and the vehicle body is greatly inclined backward. Therefore, by decelerating the vehicle and applying an inertial force to tilt the vehicle body forward, it is possible to cancel the counter-torque and keep the vehicle body posture stable. That is, when climbing a high step, it is necessary to limit the vehicle acceleration upper limit value with a negative value in order to maintain the vehicle body posture. In this embodiment, by considering such a phenomenon and its mechanism based on the vehicle acceleration and its limit value, the traveling state and the vehicle body posture can be kept stable in any stepped state.

  And main control ECU21 restrict | limits the target value of vehicle acceleration appropriately at the time of level | step difference raising / lowering.

  Specifically, the target value of the vehicle acceleration according to the amount of operation of the occupant's control device is limited by the vehicle acceleration limit value determined according to the step resistance torque. That is, when the vehicle acceleration requested by the occupant is higher than the vehicle acceleration upper limit value, the vehicle acceleration target value is set as the vehicle acceleration upper limit value. When the vehicle acceleration requested by the occupant is lower than the vehicle acceleration lower limit value, the vehicle acceleration target value is set as the vehicle acceleration lower limit value. Thus, it is possible to realize a vehicle traveling state that is closest to the occupant's request within a range in which the vehicle body posture can be stably maintained.

  In addition, if either the vehicle acceleration limiting condition due to the vehicle running performance limit or the vehicle acceleration limiting condition due to the vehicle body posture control limit cannot be satisfied, it is determined that complete control is impossible, and the vehicle posture control The target value of vehicle acceleration is determined taking into account only the limiting conditions. That is, when the upper limit value of the vehicle acceleration due to the limit of the vehicle running performance is equal to or lower than the lower limit value of the vehicle acceleration due to the limit of the vehicle body posture control, the target value of the vehicle acceleration is set to the lower limit value of the vehicle acceleration due to the limit of the vehicle body posture control. To do. Further, when the lower limit value of the vehicle acceleration due to the limit of the vehicle running performance is equal to or higher than the upper limit value of the vehicle acceleration due to the limit of the vehicle body posture control, the target value of the vehicle acceleration is set to the upper limit value of the vehicle acceleration due to the limit of the vehicle body posture control. To do. As a result, it is possible to minimize the disturbance of the vehicle body inclination particularly when raising and lowering a high step.

  Here, the state in which the complete control is impossible is a vehicle body center-of-gravity movement amount that can respond to the inertial force accompanying the acceleration by the limit of the active weight portion movement and the vehicle body inclination within the range of the vehicle acceleration that can be adjusted by the driving torque. This corresponds to a state in which the above cannot be achieved. In other words, this corresponds to a state in which vehicle acceleration that can cope with vehicle body posture control (center of gravity position control) cannot be achieved due to the limit of the driving torque. For example, if the vehicle touches a very high step, the vehicle is forced to decelerate suddenly along with the step contact, and if the inertial force that accompanies the sudden deceleration cannot be canceled even if the center of gravity of the vehicle is moved to the limit, Lean on. In this embodiment, in such a state, the limit value of the vehicle acceleration due to the limit of the vehicle body posture control is set as the target value of the vehicle acceleration, so that the ability of the vehicle body posture control is maximized. For example, in the above-described example, the vehicle body tilt forward can be suppressed as much as possible by moving the vehicle body center of gravity backward to the limit.

  In the present embodiment, the target value of the vehicle acceleration required by the occupant is determined based on the joystick operation amount of the occupant, and the relational expression for converting the joystick operation amount into the occupant requested vehicle acceleration target value is Although not depending on the step elevation state, this relational expression itself may be changed depending on the step elevation state or the vehicle acceleration limit value. For example, the maximum input amount to the front of the joystick may be set to the vehicle acceleration upper limit value considering the effect of the step, and the maximum input amount to the rear of the joystick may be set to the same lower limit value. As a result, the vehicle acceleration target value requested by the occupant is always within the allowable range, and at the same time, a greater degree of freedom for the occupant to steer can be ensured.

  Further, in the present embodiment, at the time of complete control impossibility determination, the vehicle body posture disturbance is minimized by determining the target vehicle acceleration that gives priority to the posture control. This control may be executed or added. For example, when the complete control impossibility determination continues for a predetermined time or longer, the vehicle avoidance control between the vehicle body and the road surface may be executed by notifying the passenger of a dangerous state by a warning sound or the like, or by protruding a vehicle body contact prevention stopper.

  Further, in the present embodiment, the vehicle body tilt angle limit amount due to the step is evaluated by the ratio between the substantial step height and the distance from the vehicle body tilt center to the road surface contact point, but a more rigorous method may be used. Good. For example, a vehicle body tilt angle at which a part of the vehicle body actually contacts each step height is actually measured or obtained from a drawing, and a function of the vehicle body tilt angle limit amount obtained thereby is provided as a map in advance. Then, the vehicle body tilt angle limit amount may be determined using this.

  Further, in the present embodiment, the substantial step height necessary for determining the vehicle body tilt angle limit amount by the step is theoretically estimated based on the step resistance torque, but the sensor has a sensor for measuring the step. The measurement value may be used for determination. Moreover, you may estimate the value of level | step difference resistance torque based on the measured value. Further, the vehicle body tilt angle limit amount due to the step may be determined based on the measured value of the sensor before the driving wheel contacts the step when the ascending step is approached. This can prevent the vehicle body from coming into contact with the step before the driving wheel comes into contact with the step when the vehicle body is greatly inclined forward and accelerated while entering the ascending step.

  Furthermore, in the present embodiment, a linear function is used when determining the vehicle acceleration limit value based on each condition, but a more strict nonlinear function may be used. On the other hand, a non-linear function is used when determining the substantial step height, but the calculation may be simplified by using a linear function approximating it. Further, a nonlinear function may be applied in the form of a map.

  In addition, this invention is not limited to the said embodiment, It can change variously based on the meaning of this invention, and does not exclude them from the scope of the present invention.

It is the schematic which shows the structure of the vehicle in the 1st Embodiment of this invention, and is a figure which shows the state which is carrying out acceleration advance in the state which the passenger | crew got on. It is a block diagram which shows the structure of the control system of the vehicle in the 1st Embodiment of this invention. It is the schematic which shows the level | step difference raising / lowering operation | movement of the vehicle in the 1st Embodiment of this invention. It is a flowchart which shows operation | movement of the driving | running | working and attitude | position control processing of the vehicle in the 1st Embodiment of this invention. It is a figure which shows the dynamic model of the vehicle in the 1st Embodiment of this invention, and its parameter. It is a flowchart which shows the operation | movement of the acquisition process of the state quantity in the 1st Embodiment of this invention. It is a flowchart which shows the operation | movement of the determination process of the level | step difference raising / lowering torque in the 1st Embodiment of this invention. It is a flowchart which shows the operation | movement of the determination process of the target driving state in the 1st Embodiment of this invention. It is a graph which shows the change of the target value of the active weight part position in the 1st Embodiment of this invention, and the target value of a vehicle body tilt angle. It is a flowchart which shows the operation | movement of the determination process of the target vehicle body attitude | position in the 1st Embodiment of this invention. It is a flowchart which shows the operation | movement of the determination process of the actuator output in the 1st Embodiment of this invention. It is a block diagram which shows the structure of the control system of the vehicle in the 2nd Embodiment of this invention. It is the schematic which shows the operation | movement in the raising / lowering of the level | step difference of the vehicle in the 2nd Embodiment of this invention. It is a flowchart which shows the operation | movement of the acquisition process of the state quantity in the 2nd Embodiment of this invention. It is a flowchart which shows the operation | movement of the determination process of the level | step difference raising / lowering torque in the 2nd Embodiment of this invention. It is a flowchart which shows the operation | movement of the determination process of the target vehicle body attitude | position in the 2nd Embodiment of this invention. It is a flowchart which shows the operation | movement of the determination process of the actuator output in the 2nd Embodiment of this invention. It is the schematic which shows the structure of the vehicle in the 3rd Embodiment of this invention, and is a figure which shows the state which has detected the level | step difference before the level | step difference. It is the schematic which shows the operation | movement in the raising / lowering of the level | step difference of the vehicle in the 3rd Embodiment of this invention. It is a block diagram which shows the structure of the control system of the vehicle in the 3rd Embodiment of this invention. It is a figure which shows the geometric conditions when measuring the level | step difference of the up in the 3rd Embodiment of this invention. It is a figure which shows the change of the level | step difference raising / lowering resistivity of the uphill level | step difference in the 3rd Embodiment of this invention. It is a figure which shows the geometric conditions when measuring the level | step difference of the down in the 3rd Embodiment of this invention. It is a figure which shows the change of level | step difference raising / lowering resistivity of the level | step difference of the downward in the 3rd Embodiment of this invention. It is a flowchart which shows the operation | movement of the determination process of the level | step difference raising / lowering torque in the 3rd Embodiment of this invention. It is a figure which shows the geometrical relationship of the vehicle body at the time of stepping on the level | step difference in the 4th Embodiment of this invention, and a level | step difference. It is a flowchart which shows the operation | movement of the determination process of the target state in the 4th Embodiment of this invention. It is a figure which shows each state quantity at the time of the operation | movement which could not go up the level | step difference in the 4th Embodiment of this invention. It is a figure which shows the level | step difference raising / lowering state and vehicle body attitude | position at the time of the operation | movement which could not go up the level | step difference in the 4th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Vehicle 12 Drive wheel 14 Boarding part 20 Control ECU

Claims (3)

The car body,
A drive wheel rotatably mounted on the vehicle body;
A vehicle control device for controlling the attitude of the vehicle body by controlling the drive torque applied to the drive wheels,
The vehicle control device restricts the target value of the vehicle acceleration according to a limit value of the vehicle acceleration determined according to the step resistance torque that is a resistance caused by the step when moving up and down the road step. Vehicle. The vehicle according to claim 1 , wherein the vehicle control device determines a limit value of the vehicle acceleration based on a limit of vehicle travel control and a limit of vehicle body posture control when moving up and down the step. An active weight portion movably attached to the vehicle body;
The vehicle control device of the vehicle according to claim 1 or 2 for determining the limit value of the vehicle acceleration in accordance with a movement limit position of the active weight portion.

Images