JP4724593B2 - Vehicle motion control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motion controller of a vehicle clearly guides specific control timing of accelerating, steering and braking operations, and performs the motion control based thereon. <P>SOLUTION: An ideal motion control section 42 of a central controller 40 controls the steering of the vehicle using the applied acceleration information in the longitudinal direction of the vehicle. An HVI (Human Vehicle Interface) 55 presents information for timing determination for starting the steering to the driver. The driver controls the steering starting timing based on the information presented by the HVI (Human Vehicle Interface) 55. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a vehicle motion control device that integrally controls steering, deceleration, and acceleration, and more particularly to a vehicle motion control device that controls vehicle motion using vehicle jerk information.

  In conventional vehicles, the steering wheel to the steering device that actually cuts the tire, the accelerator pedal to the engine throttle opening, and the brake pedal to the brake hydraulic device are directly connected by mechanical coupling including hydraulic pressure. On the other hand, various by-wire systems have been proposed in which the mechanical coupling is eliminated by detecting the input level of the driver to each operation unit with a sensor, converting it to an electrical signal, and transmitting it. Yes. In the by-wire system, not only the driver's input, but also the control command for the excess and deficiency is given, and it is transmitted to the steering device, engine, brake hydraulic system, and appropriate vehicle motion control is performed without being controlled by the driver's input. Can be done. These systems can be controlled independently for steering (steering), acceleration (driving), and deceleration (braking), and there is a possibility that higher functions can be realized by integrating the respective functions.

  As such an integrated control system for a vehicle, the processing unit calculates information related to a control target for operating an actuator associated with each control unit based on environmental information and operation requests around the vehicle, Information that is based on information about a calculated control target and that calculates information for sharing driving force and braking force in a control unit is known (see, for example, Patent Document 1).

JP 2005-186831 A

  The vehicle integrated control system disclosed in Patent Document 1 discloses a “framework” such as a software configuration for performing integrated control. However, it cannot be said that the advantage of the by-wire system that “appropriate vehicle motion control can be performed without being controlled by the input of the driver” is utilized.

On the other hand, the driver's intention and request are ideal vehicle movements such as “I want to run smoothly in a corner” or “I want to avoid a car in front of a sudden stop”. It is only the means and process, and the amount of operation is not the driver's intention. Further, even if the required vehicle motion, which is the driver's intention itself, is the same, the operation is naturally different depending on the driver's merits and demerits, and what is realized as a result differs. In extreme cases such as danger avoidance, even if the system is prepared to move faithfully to the input driving operation group on the vehicle side, the operation input is combined at any timing for a driver who is immature in driving operation You may not know what to do. In such a case, the driving operation may be an inappropriate input group, and the requested vehicle motion (eg avoidance) may not be realized.
In addition, when automatic driving is assumed, the driver's intention is no longer limited to the moving point information, and autonomous driving is performed using information such as a navigation system. At this time, for example, when turning a corner, there arises a problem of when to start braking and steering and at what timing to accelerate.

The purpose of the present invention, an accelerator, steer, clarified guidelines specific control timing for the brake operation is to provide a vehicle motion control system capable of performing motion control based on this.

(1) To achieve the above Symbol purpose, the present invention provides a vehicle motion control apparatus having a device for controlling the steering of the vehicle, with the longitudinal jerk information of at least a vehicle, the steering of the vehicle e Bei control means for controlling, wherein, during the period in which the value of the longitudinal jerk is near zero, but which is adapted to control so as to start the steering.
With this configuration, specific control timing guidelines for the accelerator, steer, and brake operations are clarified, and motion control based on the guideline can be performed.

  According to the present invention, specific control timing guidelines for accelerator, steer, and brake operations are clarified, and motion control based on the guideline can be performed.

  First, the concept of vehicle motion control, which is the basis of the present invention, will be described through theoretical examination and experimental results using FIGS. 1 to 13, and specific control timings for accelerator, steer, and brake operations will be described. Clarify the guidelines.

  As described above, the automobile receives a force generated only when it moves with respect to the road surface. By using this force, the automobile can freely move in the plane with the intention of the driver on the vehicle. What is important here is that the motion to be realized by the driver's intention depends not only on the amount of driving operation input by the driver but also on the motion state such as vehicle speed, vehicle longitudinal acceleration, lateral acceleration, skid angle, tire contact load, etc. That's what it means. For example, even if the rudder angle is input at a timing when no load is applied to the tire (when the tire is floating in an extreme example), a large lateral force is not generated, and even if a brake is input, it is naturally large No deceleration force is generated. In addition, in a state where a so-called counter steer is applied, the car may drift to the left side even though the steering angle is given to the right side. As described above, if the vehicle motion state, the timing of the driving operation, and the operation amount are not appropriate, the motion may be different from the intention of the driver.

Now, it is difficult to handle the movement intended by the driver quantitatively because the ratio of surrounding environmental factors is large. However, it is possible to grasp qualitatively if it is limited to a normal situation except for a state in which the position control accuracy is particularly high such as a parking operation. For example, there is an example of “smooth motion” with little acceleration / deceleration. It can also be expressed as “use tire power efficiently” or “driving operation without waste” (in the present invention, this motion and driving are called “ideal motion” and “ideal driving”).
First, the driving operation and the vehicle motion studied in the present invention will be described with reference to FIG.
FIG. 1 is an explanatory diagram of driving operation and vehicle motion studied in the present invention.

As shown in FIG. 1, the driving operation and vehicle motion considered in the present invention are basically “entering a turn while decelerating, accelerating during a turn after a constant speed turn, and exiting on a straight line”. This section describes the guidelines for brake, steer, and accelerator control operations that realize this situation. Hereinafter, in order to make the above-mentioned index concrete, examination from the viewpoint of tire characteristics, load movement physical model, vehicle kinematics, and supported experimental results will be sequentially described.
<Efficient use of tire force according to exercise conditions (vehicle kinematic approach)>
The generated force of the tire can be classified into a tire deformation force generated in the adhesive region and a friction force in the slip region. Efficient use of tires means that the lateral force with respect to the unit slip angle or slip ratio, the longitudinal force (gain) is large, the responsiveness of the generated force is high (the phase lag is small), and the tire wear is also reduced. You can think of it as less. A high gain indicates that the amount of operation such as rudder angle and brake pedaling force may be small in order to generate the same tire force, which is directly linked to "no waste driving operation". Become.

  FIG. 2 is an explanatory diagram of the relationship between the side slip angle (deg) and the cornering force (kN) for each different vertical load.

  As shown in FIG. 2, in order to increase the gain of the tire, it is important to increase the contact pressure on the contact surface, and it is necessary to increase the vertical load applied to the tire.

  In addition, the responsiveness is considered to be the arrival time from the current deformation of the tread rubber to the deformation that becomes a desired steady value. For this reason, it is important to form a history that goes straight to a desired steady deformation value without causing unnecessary deformation (no detour). For example, if the load is removed while the tread is deformed in a desired direction under a certain vertical load, the tread returns to the original state again, and the generation of force is delayed. Therefore, it is necessary to reduce a change in force such as noise until a steady generated force is obtained. In particular, the change point from the adhesive region to the slip region described above changes depending on the contact pressure of the contact surface, and the deformation form of the tire tread rubber also changes greatly. Therefore, it is necessary to reduce the rate of change of the vertical load.

In view of reducing tire resistance and tire wear, it is desirable to expand the adhesion region. It is also desirable to use tires in a range where the vertical load is large and the side slip angle and slip rate are small.
In summary, it can be seen that in order to generate tire force efficiently, it is necessary to increase the ground contact load and decrease the rate of change.

  Now, a method for efficiently using tires in a moving vehicle will be described after understanding the above characteristics of the tire alone.

  The ground load has a fixed part (stationary wheel weight) determined by weight distribution and a part (load movement) proportional to the inertial force when accelerating / decelerating in the front / rear and lateral directions.

Here, an analysis model of load movement will be described with reference to FIG.
FIG. 3 is an explanatory diagram of an analysis model for load movement.

  Fig. 3 shows what Shibabata et al. Published in "Automotive Technology Association, Vol. 47, No. 12 (1993), PP. 54-60" as "Improvement of vehicle motion performance by yaw moment control". 10 is an analysis model of load movement indicated by 10.

Based on this, the basic effect of load transfer is investigated. Loads W1 to W4 of the four wheels when acceleration / deceleration is performed during turning can be expressed by the following equations (1) to (4). (Here, the amount of forward / backward / lateral movement of the center of gravity caused by the sine component of the roll angle / pitch angle is ignored.)

Here, each coefficient KOF, KOR, KH can be expressed by the following formulas (5) to (7).

Here, KF, KR: roll rigidity of front and rear wheels, and K * F, K * R: distribution of roll rigidity of front and rear wheels. The roll rigidity distributions K * F and K * R of the front and rear wheels can be expressed by the following equations (8) and (9).

In Expressions (5) to (7), hG is the height of the center of gravity, and h * G is the distance between the center of gravity and the roll axis. The relationship between the center-of-gravity height hG and the center-to-roll axis distance h * G can be expressed by the following equation (10).

Here, dF, dR: front and rear wheel tread, WF, WR: front and rear wheel load, Gx, Gy: vehicle longitudinal acceleration and lateral acceleration.

Furthermore, when the change rate per unit time of the load of each wheel is considered here, it can be expressed by the following equations (11) to (14).

That is, it can be seen that the load change of each wheel can be expressed by a linear combination of the longitudinal jerk (Jx) and the lateral jerk (Jy) of the vehicle. “Smooth motion” can be rephrased as motion with little jerk, but this smooth motion is highly related to “motion with little load change”.

  Now, the vehicle longitudinal acceleration (jerk acceleration) and lateral acceleration (jerk acceleration) are state quantities indicating vehicle motion generated by tire force. This state quantity determines the tire vertical load and the tire force. Therefore, in order to control the motion, it is necessary to consider both “vertical load generation (W or Fz)” and “tire force (Fx, Fy) that realizes motion”.

  For example, when considering a situation where the vehicle decelerates suddenly, longitudinal forces (-Fxf, -Fxr) in the deceleration direction are generated on the front and rear wheels. Considering the front wheel, the longitudinal force increases and the vertical load increases as the front wheel longitudinal force (-Fxf) increases. On the other hand, in the rear wheel, the longitudinal force increases and the vertical load decreases as the longitudinal force (-Fxr) increases. In the case of a sharp turn, the outer tire generates a lateral force to increase the vertical load, but the inner tire generates more lateral force, and the vertical load decreases.

  When the vertical load increases as the force is applied, the gain increases with the operation. Therefore, the amount of operation is small and the driving operation without waste is possible, and it can be said that the tire is used efficiently. However, since the tires are attached to a single vehicle, it is impossible to always use the four tires efficiently in all movement conditions in a normal two-wheel steering, two-wheel drive vehicle. In the present invention, within a range that can be realized by driving operations such as an accelerator, a brake, and a steer for a normal vehicle, “smooth motion”, “use tire power efficiently”, “driving operation without waste”, That is, “ideal motion” will be described.

In summary, the operations of the driver's deceleration → turn → linear acceleration are as shown in the following (1) to (6).
(1) When entering a certain corner, the approach speed (Vc) is determined from the assumed turning radius in consideration of the centrifugal force during turning.
(2) If the current speed (Vp) is higher than Vc, braking is performed for deceleration.
(3) Steering is started at a certain timing during deceleration.

As a result of the deceleration, a load shift occurs from the rear wheel to the front wheel, the ground load on the front wheel increases, and the load on the rear wheel decreases. When the steering is started, the front wheel lateral force that is a positive yaw moment for turning is efficiently generated. The potential for generating a rear wheel lateral force that has a negative yaw moment (a direction in which yaw is stopped) is reduced.
(4) Increase the steering angle while loosening the brake.

This is considered to be a relaxation operation for switching to steady circle turning while adjusting the yaw moment so as not to become excessive.
(5) Steady circular turning with a constant steering angle This state is the state in which the vehicle behavior is most stable.
(6) Escape from turning to linear motion while accelerating This reduces the lateral force on the front wheel and causes positive load movement on the rear wheel by acceleration, increasing the lateral force on the rear wheel, It is considered that this is a relaxation operation for terminating the turning and switching to the straight running by generating a negative moment as seen from the steady circle turning).

  Among these, (3), (4), and (6) are portions where deceleration, steering, and acceleration are formulated, and the specific timing of this portion is the subject of the present invention.

  Considering the optimal timing with the above-mentioned “generating tire force efficiently” in mind, the steering start timing in (3) has the maximum deceleration after the start of deceleration, the maximum front wheel load, and the rear wheel load. Is considered the lowest. From the formulas (1) to (4) and the formulas (11) to (14), it is optimal to start the steering at the timing when the longitudinal jerk becomes zero. Of course, since there are various disturbance factors such as road surface irregularities, it is difficult to specify this one point, and it can be considered that the jerk in the front-rear direction becomes zero. Further, if the brake is kept at a constant high value, the jerk during that time becomes zero, and the start of steering is equivalent at an arbitrary timing during that period. Thus, in order to determine the steering start timing, jerk information for knowing the maximum value of acceleration in the front-rear direction is necessary.

  In order to examine the relaxation operation of releasing the brake after the start of the steering in (4), the turning operation not accompanied by the deceleration is first described, and then the situation of relaxing the deceleration is added.

Here, a front and rear two-wheel model in which a four-wheel vehicle is considered by plane motion of an equivalent front and rear two-wheel vehicle will be described with reference to FIG.
FIG. 4 is an explanatory diagram of a front and rear two-wheel model in which a four-wheel vehicle is considered by plane motion of an equivalent front and rear two-wheel vehicle.

The motion of the front and rear two-wheel model can be described as the following equations (15) and (16).

Where m is the vehicle mass, Gy is the vehicle lateral acceleration, V is the vehicle speed, β is the vehicle side slip angle, Yf and Yr are the lateral forces per front and rear wheels, Iz is the yawing moment of inertia, and r is Yaw rate, lf, and lr are distances between the center of gravity of the vehicle and the front and rear axles.

  First, when the steering is started, a side slip angle is generated in the front wheel tire, the front wheel tire generates a lateral force, and a rotational motion (yaw response) around the center of gravity of the vehicle is started. As a result, a side slip angle of the vehicle body with respect to the traveling direction is generated, a lateral force is generated in the rear tire, and eventually the front and rear wheels generate a centripetal force and start turning. The state in which the tire lateral forces of the front and rear wheels are steady values and the lateral acceleration is constant is the most stable state referred to as steady circle turning (5). In steady circle turning, there is no change in the side slip angle at the center of gravity, and the yaw rate is also constant. As can be seen from the equation (16), the yawing motion of the rear wheel is stopped by a negative yawing moment expressed by the product of the lateral force of the rear wheel and the distance from the center of gravity to the rear wheel axle.

As is clear from the equations (1) to (4), the front wheel load is large in the state where deceleration is applied, and the rear wheel load recovers as the deceleration decreases. As the lateral acceleration further increases, the vertical load on the outer tire increases. Combining this situation,
(i) Front wheel load increase due to deceleration (rear wheel load decrease)
(ii) Increase in turning outer wheel load due to lateral acceleration (decrease in inner wheel load)
(iii) Restoring the rear wheel load by reducing the speed (decreasing the front wheel load)
After that, a steady circle turn is reached. At this time, let's consider an ideal movement that is “smooth” and “uses tires efficiently”. Here, attention is paid to the tire on the outside of the turn. To consider (i) and (ii), first consider the front wheel turning outside. Considering the right turn shown in FIG. 1, the outside of the front wheel turn is the left front wheel of index 1 in FIG. Considering the main work that the left front wheel should do during (i) and (ii), it is the start of rotation (yaw response). For this purpose, FY1 is generated efficiently (although in the negative direction of FIG. 3).

Next, the state variables of the vehicle during deceleration → turning will be described with reference to FIG.
FIG. 5 is an explanatory diagram of vehicle state variables during deceleration → turning.

  5, FIG. 5 (A) shows the longitudinal / lateral acceleration during deceleration → turning in FIG. 5, and FIG. 5 (B) shows the longitudinal / lateral jerk. FIG. 5 (C) shows the front wheel outer load W1, FIG. 5 (D) shows the rear wheel outer load W3, and FIG. 5 (E) shows the yaw rate differential value (yaw angular acceleration). The horizontal axis indicates time, and steering is started at the timing of time (t1), and the brake release is completed at the timing of (t2). Further, after the time (t2), a steady circular turn (5) with a constant lateral acceleration is performed.

  As described above, steering is started at the timing (t1) when the longitudinal acceleration is maximum, that is, when the jerk is zero. As shown in FIG. 5A, the lateral acceleration then increases and the longitudinal acceleration decreases. In order to use the tire force efficiently, it is necessary to increase the ground contact load and decrease the rate of change. As a result, as shown in FIG. 5 (C), each direction so that the front wheel outer load increases monotonously. It is optimal to control the acceleration. This is due to the following reasons. The load movement (convergence value) at the time of steady circle turning is determined by the lateral acceleration, and ΔW1 is determined in advance. This is because the connection method for minimizing the rate of change of the ground load within a limited time is a straight line if the discontinuous portion of the connecting portion is ignored.

Now, in such a situation, since the time change rate of the front wheel outer load W1 in the equation (11) is constant, the following equation (17) is shown.

The relationship is established. Here, KOF and KH are determined by vehicle parameters such as vehicle weight, dimension, and center of gravity height. The rate of change K is determined by the time between ΔW1 and (A)-(B). Further, there is naturally a case where ΔW1 is zero, and K is zero at this time. In this control, it is realistic that the course is determined by the steering and fine adjustment is applied by the brake depression force. At this time, it is necessary to detect jerk in the front-rear direction and the lateral direction.

  Here, when the above-mentioned steering start timing is reconsidered with reference to the equation (17), in order to keep the K from the time of deceleration constant, if the lateral jerk is not generated at the point where the longitudinal jerk is zero, the equation The relationship (17) cannot be maintained. Therefore, it can be considered that the steering is started at the moment when Jx is zero and the relationship of Expression (17) is maintained.

  Assuming that the expression (17) is the only constraint condition, for example, an option of quickly releasing the brake, increasing the lateral jerk, and keeping K constant may be considered. However, the brake release is performed over time until (t2) for the reason (iii) described above. Hereinafter, the rear wheel outer side will be described.

  When the brake is released, the load moves to the outside of the rear wheel according to Equation (3). Since the lateral acceleration of the rear wheel is increasing while the load is originally reduced due to braking, when the braking amount suddenly disappears, the transition occurs on the load movement line due to lateral acceleration, and the load of ΔW3 The movement will come abruptly. If it becomes like this, the tire lateral force of a rear wheel will become large rapidly, and will stop a yawing movement rapidly as it exists in Formula (16). Accordingly, the brake release is inevitably smooth and continues until the timing (t2) at which the yaw angular acceleration becomes zero and steady circular turning is reached. The timing (t2) is a timing at which the lateral acceleration becomes constant, that is, a timing at which the lateral jerk becomes zero.

  As described above, in order to control the brake during turning, it is necessary to detect the lateral jerk, and the timing at which the brake is released is the timing at which the lateral jerk becomes zero.

Next, the state variables of the vehicle when escaping from the turning in the state (6) to the linear motion while accelerating will be described with reference to FIG.
FIG. 6 is an explanatory diagram of vehicle state variables when escaping from a turn in the state (6) to a linear motion while accelerating.

  6A to 6E are the same as FIGS. 5A to 5E. Acceleration is started at the timing of time (t3), and the steering of the steering is returned to the zero position at the timing of time (t4). Moreover, after time (t4), it becomes equal acceleration linear motion.

As is clear from the equations (1) to (4), the outer load is large in the turning state, and the inner load recovers as the lateral acceleration decreases to return to linear motion. Further, when the longitudinal acceleration due to the accelerator increases, the vertical load of the rear tire increases. Combining this situation,
(iv) From the increase in outer ring load (decrease in inner ring load) due to lateral acceleration,
(v) Increase in rear wheel load due to acceleration (decrease in front wheel load)
(vi) Decrease in outer ring load due to decrease in lateral acceleration by loosening rudder angle (increase in inner ring load)
After that, the constant acceleration linear motion is reached. At this time, the ideal motion of “smooth” and “use tire efficiently” will be explained.

  In order to escape from steady circular turning to linear motion, the lateral force generated by the tires against the centrifugal force is extinguished and the yawing motion held during steady circular turning is terminated. The clockwise yawing moment that had occurred up to then must be reduced. Specifically, as shown in Equation (16), it is necessary to reduce the lateral force of the four wheels to zero while balancing the lateral force of the front and rear wheels and adjusting the yawing moment.

  Again, pay attention to the tire on the outside of the turn. Considering the escape from right turn as shown in FIG. 1, the outer side of the front wheel turns to the left front wheel of index 1 in FIG.

  As shown above, since it is in a steady circular turning state, as shown in FIG. 6A, the acceleration is started at a timing (t3) when the lateral acceleration is constant, that is, the lateral jerk is zero. Thereafter, the longitudinal acceleration increases and the lateral acceleration decreases. As shown in FIG. 6C, the outer front wheel also has a large ΔW′1 due to a load reduction due to a decrease in lateral acceleration and a load reduction due to acceleration. As a result, the lateral force of the front wheels is reduced as much as possible, and the clockwise yawing moment is also greatly reduced. On the other hand, in the outer rear wheel, as shown in FIG. 6 (D), since the acceleration is increased in weight, ΔW′3 becomes smaller. As a result, the decrease in lateral force of the rear wheel is relatively less than that of the front wheel, and the decrease in the counterclockwise yawing moment is reduced. Thereby, it is possible to escape from a stable turn.

  Here, since the lateral force is reduced, the efficient use of the tire force needs to be reduced while reducing the change rate of the ground load. After all, it is optimal to control the acceleration in each direction so that the front wheel outer load in FIG. 6 decreases monotonously. This is for the same reason as the deceleration → turning in FIG. For this purpose, it is necessary to perform control to make K <0 constant in Equation (17). In this control, it is realistic to make fine adjustments by steering while keeping the accelerator constant (including full opening). At this time, it is necessary to detect jerk in the front-rear direction and the lateral direction.

The specific timing and control method of the above-mentioned (3), (4), and (6) have been described so far, and these are summarized as follows.
(3) Timing for starting steering during deceleration This is the timing at which the longitudinal jerk becomes zero.
(4) Increase the steering angle while loosening the brake.

It is necessary to control so that the front wheel outer load increases monotonously. Specifically, it is necessary to control the steering angle and the brake so that Expression (11) (when turning right) or Expression (12) (when turning left) is positive and constant. The timing at which the brake is released is the timing at which the lateral jerk becomes zero.
(6) Return the steering angle while accelerating.
Acceleration is started at the timing (t3) when the lateral jerk is zero. It is necessary to control the front wheel outer load so that it decreases monotonously. Specifically, it is necessary to control the steering angle and the accelerator so that Expression (11) (when turning right) or Expression (12) (when turning left) is negative and constant. Further, the timing at which the braking in (4) is finished is the timing at which the lateral jerk is zero. Therefore, there is a case where the timing of (4) and (6) overlaps by skipping the state of (5) steady circle turning.
<Extraction of driver driving strategy (experimental approach)>
Next, with reference to FIG. 7, the result of an actual vehicle test for verifying the validity of the above-described mechanical examination for the accelerator, the steer, and the brake operation will be described.
FIG. 7 is an explanatory diagram of an actual vehicle test.

  The vehicle used in the experiment is a front-wheel drive two-wheel steering vehicle with a front-wheel drive of 2000 cc engine and front-wheel drive. For this reason, the front wheel load is larger than the rear wheel.

  First, as Experiment I shown in FIG. 7 (A), the speed is reduced from 80 (km / h) to 60 (km / h) at point X, and at a corner of radius 40 (m) at any timing left to the driver. Entering, (1) maintaining the speed as it is and (2) accelerating. In addition, in Experiment II shown in FIG. 7B, it was verified whether the brake, the steering, the timing of the accelerator operation, and the operation strategy were changed when the course after braking → turning was made different.

Next, the result of Experiment I of the actual vehicle test will be described with reference to FIG.
FIG. 8 is an explanatory diagram of the results of Experiment I of the actual vehicle test.

  FIG. 8 is a diagram showing the results of the braking → turn → acceleration of (2) in Experiment I as a time series as in FIGS. 5 and 6 above. FIG. 8A shows the longitudinal acceleration and the lateral acceleration. FIG. 8B is a diagram showing the front and rear, lateral jerk and steering angle. FIG. 8C shows the vertical load of each wheel.

  From FIG. 8 (B), the steering start timing is the timing at which the longitudinal jerk is zero (at a time point of 0.2 (s)). In addition, the timing when the brakes are released (the longitudinal jerk is zero again) is the timing when the lateral jerk is zero (at 1.15 (s)). Furthermore, the timing at which acceleration is started is also the timing at which the lateral jerk is zero (at 1.15 (s)). In this case, there is no steady circle turning period, and the brake is released and accelerated.

  As shown in FIG. 8C, the load on the left front wheel, which is outside the front wheel, increases linearly despite occurrence of longitudinal acceleration and lateral acceleration.

Next, with reference to FIG. 9, the result of taking out the steering start timing as a result of both experiments I and II will be described.
FIG. 9 is an explanatory diagram of the result of taking out the steering start timing as a result of both experiments I and II.

  9A to 9H, the time points indicated by ◯ indicate the steering start timing.

Next, with reference to FIG. 10, the results of extracting the timing at which the brake is released and the timing at which acceleration is started will be described as the results of both experiments I and II.
FIG. 10 is an explanatory diagram of the results of taking out the timing to finish releasing the brake and the timing to start acceleration as a result of both experiments I and II.

  In FIGS. 10A to 10H, the time point indicated by ◯ indicates the timing when the brake is released, and the time point indicated by Δ indicates the timing when acceleration is started.

Next, the vertical load of each wheel will be described as a result of both experiments I and II with reference to FIG.
FIG. 11 is an explanatory diagram of the vertical load of each wheel as a result of both experiments I and II.

  The results shown in FIGS. 9 to 11 are the same as those in FIG.

Next, the results of a vehicle motion simulation using a model in which constants are adjusted in the same manner as the actual vehicle test vehicle will be described with reference to FIG.
FIG. 12 is an explanatory diagram of a result of vehicle motion simulation using a model in which constants are adjusted in the same manner as a vehicle in an actual vehicle test.

  The model uses a 10-degree-of-freedom (tire 4, 4-body-degree-of-freedom) model with constants adjusted to the same level as the actual vehicle test vehicle. Steering angle sterr and yaw rate shown in Fig. 12 (A) when the steering angle is increased at a constant speed of 60 (Km / h) and at a constant speed (1.5 (deg / s) for actual rudder) r, lateral acceleration Gy shown in FIG. 12 (B), skid angle Beta shown in FIG. 12 (C), locus of the center of gravity shown in FIG. 12 (D), and vertical load of each wheel shown in FIG. 12 (E). Fz1, Fz2, Fz3, and Fz4 are shown.

  It is well known that a vehicle that moves like this draws a clothoid curve. The clothoid curve is used as a relaxation curve for maintaining the stability of the vehicle when connecting an arc shape from a straight line on an expressway or the like. In other words, it is considered that the vehicle behavior of tracing the clothoid curve at a constant speed is stable.

  When the vertical load of each wheel shown in FIG. 12 (E) is seen, the rate of change is constant, and the rate of change of the wheel load for “smooth motion” and “use tire force efficiently” that has been disclosed so far. This is consistent with the guidelines for maintaining a constant value. From the above, it can be considered that the guideline of the present invention is a guideline for maintaining the transient stability.

  The inventors of the present invention are to determine the timing of steering, braking, acceleration, and minimize the rate of change of vertical load from the viewpoint of whether the vehicle motion and the generation of tire force are in a suitable relationship. Derived from the idea. And it was confirmed through actual vehicle tests that actual drivers are driving based on similar driving strategies. From these experimental results, the validity of the mechanical examination could be verified.

  As described above, the tire is usually used in a range where the gain increases with respect to the load. However, in a motion situation, the vertical load may reach a range exceeding this limit. In such a case, jerk generated in the opposite direction to the acceleration generated at the steering angle, accelerator, brake, etc., may be detected and controlled so that the steering angle, accelerator, brake is slightly returned. Is. As these control methods, for example, those described in Japanese Patent No. 3733929 can be used.

  Now, based on the knowledge disclosed so far, the configuration of the vehicle motion control device will be considered. It is considered that the driver performs a steering operation according to the target course and performs position feedback control so that the vehicle trajectory matches the target course. Automated driving devices that perform braking and steering in a fully automatic manner are now realized as lane-keeping systems for highways, etc., and in the future a system that automatically avoids when the vehicle ahead stops suddenly has been proposed. It seems to be that.

  These systems are systems that control the position using information from the outside world.

Next, the concept of the vehicle motion control apparatus of the present invention will be described with reference to FIG.
FIG. 13 is a conceptual explanatory diagram of the vehicle motion control apparatus of the present invention.

  The control device of the present invention enters a minor loop in a positioning closed loop composed of a controller such as a driver or a lane keep system, and in addition to steering, braking, and acceleration commands for positioning from the driver or controller, It is configured to add the commands for realizing the “smooth motion” and “ideal motion efficient use of tire power” as described above. Here, the control device of the present invention operates in such a range that the positioning closed loop system does not diverge.

  Specifically, it performs braking / steering and steering in a fully automatic manner, the driver performs some operations, and the control device takes advantage of “by-wire” and supplements it with “direct control” and provides support information to the driver. The “indirect control” that presents and assists the driving operation of the driver can be considered. If the driver in the closed loop is regarded as a controller, the control performance is improved by “information”, and the performance of the entire system is improved.

Next, the configuration and operation of the vehicle motion control apparatus according to the embodiment of the present invention will be described with reference to FIGS.
First, the system configuration of a vehicle system using the vehicle motion control apparatus according to the present embodiment will be described with reference to FIG.
FIG. 14 is a system block diagram showing a system configuration of a vehicle system using the vehicle motion control apparatus according to the embodiment of the present invention.

  The vehicle 0 is a rear wheel drive vehicle (Rear Engine Rear Drive: RR vehicle) in which the engine 1 drives the left front wheel 63 and the right front wheel 64. The driving method may be an FR vehicle or an FF vehicle. The vehicle 0 is configured by a so-called by-wire system, and there is no mechanical coupling between a steering, an accelerator pedal, and a brake pedal operated by a driver and a steering mechanism, an acceleration mechanism, and a deceleration mechanism.

  Each of the left front wheel 61, the right front wheel 62, the left rear wheel 63, and the right rear wheel 64 is equipped with a brake rotor, a wheel speed detection rotor, and a wheel speed pickup on the vehicle side to detect the wheel speed of each wheel. it can.

  The depression amount of the accelerator pedal 10 of the driver is detected by the accelerator position sensor 31 and is processed by the central controller 40 via the pedal controller 48. The powertrain controller 46 controls a throttle, a fuel injection device, and the like (not shown) of the engine 1 according to the depression amount of the accelerator pedal 10. Further, the output of the engine 1 is transmitted to the left rear wheel 63 and the right rear wheel 64 via the electronic control transmission 2 controlled by the power train controller 46. An accelerator reaction force motor 51 is connected to the accelerator pedal 10, and the reaction force is controlled by the pedal controller 48 based on a calculation command from the central controller 40.

  The steering system of the vehicle 0 is a front wheel steering device, and has a steer-by-wire structure in which there is no mechanical connection between the steering angle of the driver and the tire turning angle. The steering system includes a power steering 7 including a steering angle sensor (not shown) therein, a steering 16, a driver steering angle sensor 33, and a steering controller 44. The steering amount of the driver's steering wheel 16 is detected by the driver steering angle sensor 33 and is processed by the central controller 40 via the steering controller 44. The steering controller 44 controls the power steering 7 according to the steering amount of the steering 16. In addition, a steering reaction force motor 53 is connected to the steering 16, and the reaction force is controlled by the steering controller 44 based on a calculation command from the central controller 40.

  The depression amount of the brake pedal 11 of the driver is detected by the brake pedal position sensor 32 and is processed by the central controller 40 via the pedal controller 48.

  Each of the left front wheel 61, the right front wheel 62, the left rear wheel 63, and the right rear wheel 64 is provided with a brake rotor, and a caliper that decelerates the wheel by sandwiching the brake rotor with a pad (not shown) on the vehicle body side. Is installed. The caliper is a hydraulic type or an electric type having an electric motor for each caliper. Each caliper is basically controlled by a brake controller 451 (for front wheels) and 452 (for rear wheels) based on a calculation command from the central controller 40. Further, as described above, the wheel speeds of the respective wheels are input to the brake controllers 451 and 452, and the vehicle speed V is calculated. These signals are constantly monitored as shared information by the central controller 40. A brake reaction force motor 52 is connected to the brake pedal 11, and the reaction force is controlled by the pedal controller 48 based on a calculation command from the central controller 40.

  Next, the motion sensor group of this embodiment will be described. As shown in FIG. 14, the lateral acceleration sensor 21 and the longitudinal acceleration sensor 22 are arranged in the vicinity of the center of gravity. Differentiating circuits 23 and 24 for differentiating the outputs of the respective acceleration sensors 21 and 22 to obtain jerk information are mounted. In the present embodiment, it is illustrated that each sensor is installed in order to clarify the existence of the differentiation circuit. However, in actuality, the acceleration signal is directly input to the central controller 40 to perform various arithmetic processes, and then the differentiation process is performed. It may be.

  In addition, the vehicle 0 is equipped with an HVI (Human Vehicle Interface) 55 that transmits assist information used for “indirect control” transmitted from the ideal motion control unit 42 to the driver.

  The vehicle 0 has a “driver mode” that exercises mainly based on input from the driver, and an “automatic operation mode” that is omitted in detail. The central controller 40 is configured so that the automatic operation control unit 41, the driver operation control unit 43, and the ideal motion control unit 42 of the present embodiment can exchange signals with each other. The automatic driving control unit 41 is active when in the “automatic driving mode”, and includes an absolute position signal from the GPS captured by the external sensor group 39, a ranging signal from the radar, various information from the beacon, a position signal from the thumbnail, and the like. Based on the signals from the in-vehicle yaw rate sensor 38, wheel speed sensor, or acceleration sensor, the position of the vehicle is controlled to be the position of the target route. The ideal motion control unit 42 communicates with the automatic operation control unit 41 and the driver operation control unit 43, and in addition to the positioning operation based on the automatic operation control unit 41 or the driver input, “direct control” or a driver is interposed. Perform “indirect control”.

Next, the relationship of control input / output in the vehicle motion control apparatus according to the present embodiment will be described with reference to FIG.
FIG. 15 is a system block diagram showing the relationship of control input / output in the vehicle motion control apparatus according to the embodiment of the present invention.

  FIG. 15 shows a control input / output relationship between the ideal motion control unit 42 and the positioning control driver or the automatic operation control unit 41 inside the central controller 40.

  In the conventional motion control device, control is performed to follow the side slip angle and yaw rate response obtained by inputting the target course, vehicle speed, driver rudder angle, and the like into the motion reference model.

  On the other hand, in the present embodiment, in addition to this, a portion for causing the change rate K of the vertical load of the tire expressed by the equation (17) to follow the target load movement change rate Kd is added, and the ideal motion control unit 44 performs this control operation. In FIG. 15, only target course following is described, and the yaw rate is omitted in the integral description of the motion.

Depending on the deviation from the target course, the automatic operation control unit 41 and the driver operation control unit 43 set the tire slip ratio s of each wheel and the side slip angle β of each wheel to the brake, accelerator, steering rudder with respect to the vehicle 0. Adjust according to the angle (M _DC (s, β)). Ideal motion control unit 44, the correction operation in the "direct control" _{(M IC (s, β)} ) is added. In “indirect control”, support information is determined based on this amount and presented to the driver.

  This control is not always performed, but only mainly during turning or when a load change occurs due to a disturbance as shown in FIG.

Here, in the present embodiment, the control start time and end time are set as follows. From the concept of motion control mentioned earlier,
At the start of control: When braking or acceleration starts (occurrence of longitudinal jerk)
At the end of control: When turning steady or going straight (zero lateral jerk)
Therefore, each component of jerk is detected in advance, and the control start and end are automatically determined by comparing with any specified value.

  Next, a method for setting the target load movement change rate Kd will be described. The acquisition method differs depending on the “automatic operation mode” and the “driver mode”. The specific contents of each mode will be described below.

1) Automatic Driving Mode First, the contents of control in the automatic driving mode in the vehicle motion control apparatus according to the present embodiment will be described with reference to FIG.
FIG. 16 is an explanatory diagram of the control contents in the automatic operation mode in the vehicle motion control apparatus according to the embodiment of the present invention.

In the automatic driving mode, basic positioning control and vehicle attitude control such as the yaw angle of the vehicle are achieved by the automatic driving control unit 41. The current vehicle speed (V ₀ ) can be measured from the wheel speed or GPS information. Further, the distance to the corner (X ₀ ), the radius of the corner (R), and the set vehicle speed (V _R ) in the corner shown in FIG. 16A are known from terrain information obtained from various sensors and maps. With such information, the automatic operation control unit 41 does not know the “integrated control” guidelines for when and how to operate the brake and the steering. FIG. 16 (B) shows the acceleration at this time, FIG. 16 (C) shows the speed (vehicle speed), FIG. 16 (D) shows the position on the target course, and FIG. 16 (E) shows the outside of the front wheel. The load W1 is shown. Here, for the sake of simplification, it is considered that the control method of the tire slip ratio s and the side slip angle β of each wheel so that the jerk generated by the brake and the steering is constant, and the vehicle longitudinal and lateral jerk are considered. Is controlled to be constant during a predetermined period.

As shown in FIGS. 16A and 16B, the _vehicle decelerates at the jerk J _x1 from X0 before the corner advance acquisition, and after time T1, the deceleration is slowed (the longitudinal jerk is zero) and the steering is started at the same time. Thereafter, the lateral acceleration is decreased in jerk J _y, longitudinal acceleration increases at jerk J _x2. And then after a lapse of time T2, the vehicle, the radius R, the steady circular turning velocity V _R. At this time, the lateral jerk becomes zero, the brake loosening operation is completed, and the longitudinal jerk becomes zero. Here, what is desired to be embodied are four variables of jerk J _x1 , J _x2 , times T1 and T2. In addition, _{J y is} determined as (J x1 _{-J x2).} At this time, the following four relational expressions (18), (19), (20), and (21) are established.

Since there are four unknowns and four relational expressions, J _x1 , J _x2 , T1 and T2 are _specified , and the target Kd at this time can be determined as in the following Expression (22).

As described above, in the automatic operation mode, the target _Kd from an arbitrary brake start point can be calculated. Further, when the vehicle speed (V ₀ ) is the set vehicle speed (V _R ) in the corner from the beginning, the jerk in the front-rear direction becomes zero, and a constant turn of the jerk J _y is started from the position X 0, and then a steady circle It will turn. The trajectory until the steady circle turns is a clothoid curve as described in FIG.
2) Driver Mode Next, the control contents in the driver mode in the vehicle motion control apparatus according to the present embodiment will be described with reference to FIG.
FIG. 17 is an explanatory diagram of control contents in the driver mode in the vehicle motion control apparatus according to the embodiment of the present invention.

Here, a method of acquiring the target _Kd for the driver mode will be described. From the equation (22) studied in the previous section, the following can be understood.

  The target Kd is determined by Jx1 (initial acceleration before and after braking).

  When braking is not necessary, Kd is determined by Jy (initial steering lateral jerk).

  Furthermore, the following phenomena can be confirmed by looking at the results shown in FIGS. 11E and 11F showing the experimental results shown above.

  -When braking takes a long time, it is considered separately from linear braking, and this part is regarded as a DC component offset, and Kd is newly determined by Jy by steering.

In this way, in the driver mode, after all, as shown in FIGS. 17 (A) and 17 (B), J _x (initial braking longitudinal jerk) and J _y (initial steering lateral jerk) as shown in (C). The case where it is decided is considered.

Therefore, in any case, the target K _d is _obtained by measuring the _{initial jerks} J _{x_start} and J _{y_start} at the start of the operation as the following equation (23):

Can be obtained.

As described above, the target load movement change rate _Kd can be obtained also in the “automatic operation mode” and the “driver mode”. In particular, in the “automatic operation mode”, since there is no input from the driver, the control unit alone can freely adjust the tire slip ratio s of each wheel and the side slip angle β of each wheel by the brake, accelerator, and steering angle. It is possible to realize a configuration in which the longitudinal jerk and the lateral jerk of the vehicle according to the present invention are detected, the steering is started at the same time as the longitudinal jerk is zero, and the brake releasing operation is terminated when the lateral jerk becomes zero. .

  Although not shown here, the longitudinal and lateral jerk of the vehicle is detected in an equivalent manner as is apparent from the relationship of deceleration → turning, turning → linear acceleration shown in FIGS. It is also possible to realize a configuration in which the lateral jerk starts accelerating at the same time as zero and the operation of returning the steering is terminated when the longitudinal jerk becomes zero.

Next, the control contents in the driver mode in the vehicle motion control apparatus according to the present embodiment will be described with reference to FIG.
FIG. 18 is a flowchart showing the control contents in the driver mode in the vehicle motion control apparatus according to the embodiment of the present invention.

In the case of the driver mode, the correction operation (M _IC (s, β)) by the ideal motion control unit 44 and the driving operation by the driver (M _DC (s, β)) are interactively related. The functional aspects of drivers are not necessarily all described in a uniform and uniform manner. Therefore, there is no corrective operation that is definitely optimal for all drivers, and there is no point in complicating it unnecessarily. Here, FIG. 18 shows a minimum example of the control algorithm.

Step S00) Processing start Step S01) The longitudinal jerk J _x [i] and the lateral jerk J _y [i] of the vehicle are measured. At this time, it is determined whether or not the jerk is approaching zero as compared with the longitudinal jerk J _x [i-1] and the lateral jerk J _y [i-1].
Step S02) A jerk J [i] (i-th jerk vector magnitude) is obtained.
Step S03) The lateral component ratios I _x [i] and I _y [i] are obtained before and after jerk.
Step S04) Compare the jerk J [i] with the threshold level I _gsh ,
If J [i] <I _gsh : steady state → to step S01)
When J [i]> I _gsh : deceleration or steering start → to step S05).

Step S05) The i-th load movement change rate is calculated.
Step S06) It is determined whether the target load movement change rate Kd is set,
If not set → go to step S07)
If already set, go to step S10).
Step S07) Before and after the jerk, the lateral component ratios I _x [i] and I _y [i] are compared,
If I _x [i]> Iy [i] → go to step S08)
If I _x [i] <Iy [i] → to step S09).
Step S08) The target load movement change rate _Kd is determined by the longitudinal jerk.
Step S09) The target load movement change rate _Kd is determined by the lateral jerk.

Step S10) The tire force correction amount is determined and calculated. The force correction amount is calculated according to the difference between the target load movement change rate Kd and the i-th load movement change rate.
Step S11) A tire force correction amount distribution calculation is performed. The tire force correction amount determined in step S010 is distributed to the side slip angle β and the longitudinal slip rate (slip rate) s based on the current configuration ratio of the longitudinal jerk and the lateral jerk. In order to realize the respective correction amounts, the lateral slip angle β is corrected by the steering angle, and the vertical slip rate (slip rate) s is corrected by the brake braking force. With regard to this ratio, for example, when I _x [i] is large, the driver is actively controlling the braking force, and the correction is only the steering angle, or when I _y [i] is large, the driver In a situation where the steering angle is actively controlled, the correction should be only the braking force or change.

Step S12) Judgment of degree of achievement to steady circle turning. Determining the degree to reach steady circle turning from the absolute value of lateral jerk. At this time, the i-th and previous jerk information may be used.
J _y [i]> Jsth: The vehicle is decelerating. (To step S01)
J _y [i] <Jsth: A steady circular turn has been reached. → To step S13).
Step S13) The target load movement change rate _Kd is reset, and the process returns to Step S01.

With the above,
・ Determine whether to set the target load movement change rate from the longitudinal jerk or the lateral jerk by detecting the braking → cornering situation.
・ Determine the amount of tire force correction to correct subsequent vehicle behavior and add correction to vehicle motion.
・ When the mitigation operation at the beginning of the turn is completed and the steady circle turn, the target weight change rate is returned to zero.
Is repeated, and ideal exercise is realized.

Next, the contents of control at the time of driver assist, which is “indirect control” in the vehicle motion control apparatus according to the present embodiment, will be described with reference to FIG.
FIG. 19 is a flowchart showing the control contents during driver assist, which is “indirect control” in the vehicle motion control apparatus according to the embodiment of the present invention.

FIG. 19A shows actual jerk (J _x ) in the front-rear direction and lateral jerk (J _y ). As shown in the figure, the recommended steering start range is a range from about 0.3 (s) to 1.1 (s) where the longitudinal jerk is zero. In this example, the driver starts steering around 0.8 (s) within the recommended steering range. The steady circular turning starts after 1.8 (s) when the lateral jerk becomes zero, but the range from the start of steering to this point is the braking force fine adjustment range. Further, after the lateral jerk becomes zero (after 1.8 (s)), the acceleration start recommended range can be accelerated at any time, but in this example, the acceleration is from 2.5 (s).

  In order to present the recommended range as described above to the driver, the visual information, the auditory information, the reaction force change to the brake pedal, the steering wheel, the accelerator pedal, or some of them are transmitted in combination. There is a need.

  FIG. 19B shows presentation by “color” as an example of display. These “icons” are presented on an HVI (Human Vehicle Interface) 55 that conveys assist information used for “indirect control”, and the color changes or turns off to convey timing. For example, the icon of the brake pedal (the pedal indicated as B in the figure) starts with “blue” which is the normal brake state since the brake has already been depressed from 0 seconds in this example. When the steering is started, it is necessary to finely adjust the braking force, so that the color changes from blue to “yellow”. And after braking is completed, the light is turned off.

  Similarly, regarding the icon display of the steering, initially, the deceleration is increased by braking, and the jerk in the front-rear direction is negative. Therefore, steering is “red” in a prohibited state. From here, the display changes to “blue” when entering the recommended steering start timing range. In this example, since the steering by the driver enters at 0.8 (s), the setting is made to change to “yellow” indicating “cooperation control with brake”. Further, a portion near the steering may be an intermediate color. When the cooperative control is finished and a steady circle turns, the color changes to “blue”, and the display is turned off so that the display gradually fades out from the time when acceleration starts.

  The icon of the accelerator pedal (the pedal indicated as A in the figure) is turned off until 1.8 (s) when the steady circular turning starts. After that, it is lit in blue, and assist information is visually transmitted so that steady circular turning, that is, acceleration can be started in a range where the lateral jerk is zero.

  As described above, the HVI 55 is used to present the icon color to the driver. It is possible to visually provide support information for determining the timing for starting steering, the timing for ending deceleration, and the timing for starting acceleration from “within recommended range”. Thereby, the “indirect control” of the present invention can be realized.

  FIG. 19C shows the concept of presenting support information by reaction force or an alarm issued from the HVI 55. The brake reaction force is constant at the stage of entering the deceleration operation. Now, after the steering is started (around 0.8 (s)), it is necessary to reduce the deceleration. Here, the aim is to increase the reaction force and decrease the pedaling force of the driver (push-back operation).

  Further, the steering reaction force is configured to apply torque so as to encourage steering. Further, a fluctuation component may be superimposed on the torque to generate a “tactile signal”. Further, the start of steering may be urged by changing the frequency and amplitude over time.

  Further, with respect to the accelerator reaction force, a tactile signal may be added at the stage where the steady circular turning state is reached to urge that the accelerator reaction force is within the recommended acceleration start range. Similarly to this reaction force, the HIV 55 decides to “change” the sound volume, frequency, interval as a dial tone, etc., as with the reaction force command. It is possible to visually give support information for determining the timing to start steering, the timing to end deceleration, and the timing to start acceleration from “within recommended range”. Thereby, the “indirect control” of the present embodiment can be realized.

  In the “indirect control” of the present embodiment, the driver can receive timing while feeling the jerk as bodily sensation information. In other words, the driver can obtain “input” of jerk and correct timing, that is, “teacher signal”. This is so-called “supervised learning”, which is discussed as a learning method of a neural network. According to the present invention, it is possible to construct a new system that gives insight and suggestion to a driving operation to a driver and prevents the deterioration of driving ability due to control dependence.

  In the present embodiment, the driver performs optimum control by presenting the driver with a method or apparatus for automatically steering, braking / acceleration control using the longitudinal and lateral jerk information, or by presenting the optimum timing to the driver. Inventions have been disclosed for devices that support this. Actually important information is change rate information of the vertical load of each tire wheel of the equations (11) to (14). This is a linear combination of the longitudinal jerk and the lateral jerk multiplied by a fixed value determined from the vehicle specifications. Therefore, the vertical load of each wheel is directly measured.For example, when the vertical load of the front wheel is maximum, the assist information for starting the steering is presented, and the increase rate of the vertical load of the turning outer wheel is constant. You may control so that it may become. At present, load meters that handle large loads with high accuracy are expensive, and in this embodiment, longitudinal jerk and lateral jerk are detected and used for control and support. Therefore, it is possible to measure the load or physical quantity that reflects the load by some means (for example, the spring displacement of the suspension device, etc.), and support the control or driver according to the same timing as this embodiment or the control target. Such controls and control devices are within the scope of the present invention.

  Moreover, detecting the acceleration and further detecting the maximum value is equivalent to detecting the point in time when the jerk is zero, even though it does not appear explicitly. It is within the scope of the present invention to initiate steering, braking and drive control.

  In the present embodiment, it has been mentioned that the timing of steering, braking, or driving coincides with the timing when the longitudinal jerk or the lateral jerk becomes zero. However, it is inevitable that noise is mixed in not only the jerk signal but also in all signals, and “the vicinity of zero jerk” in the claims of the present invention includes a case where noise is mixed. Is meant to be.

  Finally, the academic position of the present invention will be described. In the present invention, control is performed to keep the vertical load change rate K constant. By the way, making the vertical weight change rate K constant is actually equivalent to the following proposition using the concept of the variational method.

"In FIG. 5, when changing the ΔW1 in period t _f, to achieve a change in acceleration as the integrated value (J) is the minimum of the mean square of the longitudinal jerk and lateral jerk, for a period t _f"

  On the other hand, if the motion trajectory plan of the human hand is designed to have a minimum jerk, “T. Flash, N. Hogan: The Coordination of Arm Movements-An Experimentally Confirmed Mathematical Model, Journal of Neuroscience, Vol.5, No.7, p.1688-1703 (1985) ”.

  It is a new discovery that the jerk of the “vehicle” is controlled to be a minimum even in the “vehicle driven by a human being”.

  Since the mean square sum of the longitudinal jerk and the lateral jerk is controlled to be the minimum, even in the steering control that exclusively controls the lateral direction, the longitudinal jerk information is required, and the longitudinal direction is exclusively controlled. That is, even in the deceleration / acceleration control to be performed, longitudinal acceleration / deceleration information is necessary.

  As described above, according to the present embodiment, the first object of the present invention is to clarify a specific control timing guideline for accelerator, steer, and brake operations and to provide a motion control device based on the guideline. Is achieved. At the same time, the second object of the present invention of providing a system in which a driver can obtain a guide for his / her driving operation by presenting a specific control guide to the driver is achieved.

  The force governing the motion of the vehicle is the force that the tire receives from the ground due to the relative motion of the tire attached to the vehicle and the ground, except for air resistance. In addition, a coupled phenomenon is formed in which the cause and the result are repeated one after another, such that the vehicle moves by the force and receives a new force.

  In order for the driver on the vehicle to control the movement of the vehicle, the tire is realized by the force that the tire receives from the ground (hereinafter referred to as the tire force), and the tire force generated for the first time by the movement is desired. It must be controlled to be suitable for realizing the movement to be performed. If this relationship is not satisfied, the exercise will fail or the tire will fail. For example, a straight forward state is a state where the front wheels are braked and the rear wheels are driven. Also, if the balance between the forces generated by the front and rear wheels during turning is inadequate due to load movement, an inappropriate motion such as drift-out or spin will occur.

  It is difficult to derive an optimal motion control method for all vehicles. However, if the situation is limited, for example, starting from deceleration to turning, or starting from linear acceleration to turning, an appropriate control method that is valuable in engineering can be found.

  In other words, in order to achieve the first and second objects of the present invention, the vehicle motion control device of the present invention comprises a device for controlling the steering of the vehicle, (at least detecting the longitudinal acceleration of the vehicle). The vehicle steering is controlled using at least jerk information in the longitudinal direction of the vehicle. Specifically, when the vehicle is steered while decelerating, control is performed so that steering is started during a period in which the value of the jerk in the front-rear direction is near zero. The vehicle motion control apparatus of the present invention has an automatic steering mechanism independent of the driver, and controls the steering start timing. In addition, the vehicle motion control apparatus of the present invention includes information presentation means for presenting information for timing determination for starting steering to the driver, and is configured to control the steering start timing by the driver. The presenting means presents at least one of visual information, auditory information, or torque input to the steering device.

  The vehicle motion control apparatus according to the present invention includes a device for controlling acceleration / deceleration of the vehicle, and has at least means for detecting lateral jerk of the vehicle, and at least lateral jerk of the vehicle. Information is used to control the acceleration / deceleration of the vehicle. Specifically, when steering is performed while decelerating, the deceleration is terminated during a period in which the value of the lateral jerk is near zero. In addition, the vehicle motion control apparatus of the present invention has an automatic deceleration mechanism that is independent of the driver, and controls the timing to end deceleration. In addition, the vehicle motion control apparatus of the present invention includes information presenting means for presenting information for timing determination for stopping deceleration to the driver, and is configured to control the timing for stopping deceleration by the driver. The means presents at least one of visual information, auditory information, or reaction force input to a deceleration device such as a brake pedal.

Further, during steering, control is performed so that acceleration is started at least during a period in which the lateral jerk value is near zero. The vehicle motion control device of the present invention has an automatic acceleration mechanism independent of the driver, and controls the timing for starting acceleration. The vehicle motion control apparatus according to the present invention further includes information presenting means for presenting information for timing determination for starting acceleration to the driver, and is configured to control the timing for acceleration by the driver. Presents at least one of visual information, auditory information, or reaction force input to an accelerator such as an accelerator pedal.

It is explanatory drawing of the driving | running operation | movement and vehicle motion which are examined in this invention. It is explanatory drawing of the relationship between the side slip angle (deg) and cornering force (kN) for every different vertical load in this invention. It is explanatory drawing of the analysis model of the load movement in this invention. FIG. 4 is an explanatory diagram of a front-rear two-wheel model in which a four-wheel vehicle according to the present invention is considered by a plane motion of an equivalent front-rear two-wheel vehicle. It is explanatory drawing of the state variable of the vehicle at the time of deceleration-> turning in this invention. It is explanatory drawing of the state variable of the vehicle at the time of escaping from the turning which is the state of (6) in this invention to acceleration while accelerating. It is explanatory drawing of the actual vehicle test in this invention. It is explanatory drawing of the result of experiment I of the actual vehicle test in this invention. It is explanatory drawing of the result which took out the timing of a steering start as a result of both experiment I and II in this invention. It is explanatory drawing of the result which took out the timing which complete | releases a brake, and the timing which starts acceleration as a result of both experiment I and II in this invention. It is explanatory drawing of the vertical load of each wheel as a result of both experiment I and II in this invention. It is explanatory drawing of the result of the vehicle motion simulation using the model by which the constant was adjusted equivalent to the vehicle of the actual vehicle test in this invention. 1 is a conceptual explanatory diagram of a vehicle motion control apparatus according to the present invention. FIG. 1 is a system block diagram showing a system configuration of a vehicle system using a vehicle motion control device according to an embodiment of the present invention. It is a system block diagram which shows the relationship of the control input / output in the movement control apparatus of the vehicle by one Embodiment of this invention. It is explanatory drawing of the control content at the time of the automatic driving mode in the vehicle motion control apparatus by one Embodiment of this invention. It is explanatory drawing of the control content at the time of driver mode in the vehicle motion control apparatus by one Embodiment of this invention. It is a flowchart which shows the control content at the time of driver mode in the vehicle motion control apparatus by one Embodiment of this invention. It is a flowchart which shows the control content at the time of driver assistance which is "indirect control" in the vehicle motion control apparatus by one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 0 ... Vehicle 1 ... Engine 2 ... Electronic control mission 7 ... Power steering 10 ... Accelerator pedal 11 ... Brake pedal 16 ... Steering 21 ... Lateral acceleration sensor 22 ... Longitudinal acceleration sensor 23, 24 ... Differentiation circuit 31 ... Accelerator sensor 32 ... Brake sensor 33 ... Steering angle sensor 38 ... Yaw rate sensor 39 ... External sensor 40 ... Central controller 41 ... Automatic operation controller 42 ... Ideal motion controller 43 ... Driver operation controller 44 ... Steering controller 46 ... Powertrain controllers 451, 452 ... Brake controller 48 ... Pedal controller 51 ... Accelerator reaction force motor 52 ... Brake reaction force motor 53 ... Steering reaction force motor 55 ... HVI (Human Vehicle Interface)
61 ... Left front wheel 62 ... Right front wheel 63 ... Left rear wheel 64 ... Right rear wheel

Claims (4)

In a vehicle motion control device having a device for controlling steering of a vehicle,
Using at least longitudinal jerk information of the vehicle, e Bei control means for controlling the steering of the vehicle,
The vehicle control apparatus according to claim 1, wherein the control means performs control so as to start steering during a period in which a longitudinal jerk value is in the vicinity of zero . The vehicle motion control device according to claim 1 ,
Equipped with an automatic steering mechanism independent of the driver,
The vehicle motion control apparatus, wherein the control means controls a steering start timing of the automatic steering mechanism. The vehicle motion control device according to claim 1 ,
Comprising information presenting means for presenting information for determining timing for starting steering to the driver;
The vehicle motion control apparatus, wherein the steering start timing is controlled by a driver based on information presented by the information presenting means. The motion control apparatus for a vehicle according to claim 3 ,
The vehicle motion control device, wherein the information presenting means presents at least one piece of information of visual information, auditory information, or torque input to a steering device.

Images