JPH10258756A - Steering device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly switch to a normal steering mode according to the intention of a driver without being influenced by external disturbances if an emergency situation occur in an automatic steering mode in a vehicular steering device capable of selecting the automatic steering mode and the normal steering mode. SOLUTION: A steering mode is switched between an automatic steering mode for causing an actuator 50 to generate a steering force and a normal steering mode for causing a driver to generate a steering force based on a command signal from a controller. During the automatic steering, a value corresponding to a steering force added other than the steering force generated by the actuator 50 is detected. Then, determination is made as to whether the added steering force is one added by the driver or the outside to a vehicle. If the added steering force is determined to be one added by the driver and a value corresponding to the added steering force exceeds a specified value, the automatic steering mode is switched to the normal steering mode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering device capable of automatically steering a vehicle.

[0002]

2. Description of the Related Art In recent years, a control device generates a command signal based on a guidance signal sent from a road, a detection signal of a road or surrounding conditions, and the like, and a vehicle is automatically controlled by a steering force generated by an actuator based on the command signal. Development of a steering device for steering is in progress.

In such a steering device,
In order to cope with an emergency or the like, it is required that the driver can switch from the automatic steering mode to a normal steering mode in which a driver generates a steering force.

In view of the above, there is provided means for determining a deviation between a command steering angle corresponding to a command signal to the actuator and an actual steering angle. When the difference is equal to or greater than a set value, it is determined that the driver is against automatic steering. It is considered to make a judgment and switch from the automatic steering mode to the normal steering mode.

[0005]

However, when the steering angle is actually changed against the steering force generated by the actuator, a great deal of labor and time is required for the driver. Therefore, there is a problem that an emergency situation cannot be dealt with promptly.

[0006] In addition to the steering force generated by the actuator during the automatic steering, a steering force may be externally applied to the vehicle based on disturbances such as unevenness and a cross wind on a traveling road. In the conventional configuration, there is a problem that the steering force externally applied to such a vehicle is erroneously determined as the steering force by the driver, and the vehicle is erroneously switched from the automatic steering mode to the normal steering mode.

It is an object of the present invention to provide a vehicle steering device that can solve the above-mentioned problem.

[0008]

According to the present invention, a steering mode is set between an automatic steering mode in which an actuator generates a steering force based on a command signal from a control device and a normal steering mode in which a driver generates a steering force. The present invention is applied to a switchable vehicle steering device.

One of the features of the present invention is that, during automatic steering, means for detecting a value corresponding to a steering force applied in addition to the steering force generated by the actuator, and that the additional steering force is added by a driver Means for judging whether the vehicle has been applied or externally added to the vehicle, and when the additional steering force is added by the driver and the value corresponding to the additional steering force is equal to or more than the set value, the automatic steering mode is switched to the normal mode. Means for switching to the steering mode. According to this configuration, it is possible to switch to the normal steering mode without changing the actual steering angle only by the driver applying the steering force during the automatic steering. As a result, it is possible to quickly switch from the automatic steering mode to the normal steering mode in an emergency or the like. Moreover, since it is determined whether the steering force applied during the automatic steering is applied by the driver or externally applied to the vehicle based on disturbance such as unevenness or a cross wind on the traveling path,
It is possible to prevent the vehicle from being erroneously switched from the automatic steering mode to the normal steering mode by the steering force externally applied to the vehicle.

In the steering apparatus according to the present invention, means for determining whether there is a possibility of collision between the vehicle and an obstacle detected in the steering direction by the additional steering force, the additional steering force being added by the driver, and Means for switching from the automatic steering mode to the normal steering mode when a value corresponding to the additional steering force is equal to or greater than the first set value; and a value corresponding to the additional steering force, the additional steering force being added by the driver. Means for switching from the automatic steering mode to the normal steering mode when the value is less than the first set value and is equal to or more than the second set value and there is no possibility of collision between the obstacle and the vehicle. Is preferred. According to this configuration, when the value corresponding to the driver's additional steering force during the automatic steering is equal to or greater than the first set value, even if there is a possibility that the vehicle will collide with the obstacle in the steering direction due to the additional steering force, The mode is switched from the automatic steering mode to the normal steering mode. As a result, when the need for steering by the driver increases during automatic steering, for example, when the driver applies a large steering force to avoid an obstacle in front, another obstacle in the steering direction due to the additional steering force is generated. Even if there is a possibility of collision with an object, a large accident or the like can be prevented by steering the driver to avoid an obstacle ahead. Further, when the value corresponding to the driver's additional steering force during the automatic steering is less than the first set value and equal to or greater than the second set value, the possibility of collision between the obstacle and the vehicle in the steering direction due to the additional steering force is increased. If there is no, the mode is switched from the automatic steering mode to the normal steering mode. This makes it possible to ensure safety when the driver switches to the normal steering mode by applying a steering force during automatic steering.

[0011] In the present invention, the additional steering force is added by the driver, and a value corresponding to the additional steering force is less than the first set value and equal to or more than the second set value. It is preferable that a means is provided for switching from the automatic steering mode to the normal steering mode when there is a possibility of collision with the vehicle and suppressing the driver's steering. If the value corresponding to the driver's steering force is less than the first set value and greater than or equal to the second set value, the urgency of the driver's steering is low. Therefore, if there is a possibility that the obstacle will collide with the vehicle in the steering direction due to the additional steering force, the driver switches from the automatic steering mode to the normal steering mode and suppresses the driver's steering, so that the driver recognizes the presence of the obstacle. Can be done.

In the present invention, the steering force generated by the driver is transmitted from the steering wheel to the wheels via the steering shaft, and transmitted as a value corresponding to the additional steering force by the steering shaft based on the additional steering force. Torque is determined, and the steering wheel side and the wheel side of the steering shaft are
Means for obtaining a value corresponding to the rotation angle of the steering shaft on the steering wheel side in a time-series manner, corresponding to the rotation angle of the steering shaft on the steering wheel side, and corresponding to the rotation angle of the steering shaft on the wheel side. Means for obtaining a value in time series is provided, and when the change in the rotation angle of the steering shaft on the steering wheel side precedes the change in the rotation angle on the wheel side, the additional steering force is added by the driver. When it is determined that the change in the rotation angle on the wheel side of the steering shaft precedes the change in the rotation angle on the steering wheel side, it is preferable to determine that the additional steering force is externally applied to the vehicle. According to this configuration, when a steering force other than the steering force generated by the actuator during the automatic steering is added,
A value corresponding to the additional steering force can be determined based on the torque transmitted by the steering shaft. When the change in the torque is based on the steering force applied by the driver, the change in the rotation angle of the steering shaft on the steering wheel side precedes the change in the rotation angle on the wheel side. When the change in the torque is based on a steering force externally applied to the vehicle, the change in the rotation angle of the steering shaft on the wheel side precedes the change in the rotation angle on the steering wheel side. This makes it possible to reliably determine whether the additional steering force is applied by the driver or externally to the vehicle.

[0013] In the present invention, the actuator comprises:
A brushless motor having a rotor concentrically rotating with the steering shaft, a stator surrounding the rotor, and a detector for detecting the rotation angle of the rotor is provided. The value corresponding to the rotation angle on the wheel side is obtained in a time series, and the hydraulic actuator for generating the steering assist force and the torque transmitted from the steering shaft to the hydraulic oil pressure supplied from the pump to the hydraulic actuator are transmitted. A control valve that controls the rotation angle of the steering shaft on the wheel side of the brushless motor, and a second detector of the rotation angle of the steering shaft on the wheel side of the control valve is provided. The value corresponding to the rotation angle of the steering shaft on the wheel side is determined by the second detector. Sought, the rotation angle of the steering shaft obtained by the detector of the rotation angle of the rotor, from the difference between the rotation angle of the steering shaft obtained by the second detector, preferably the torque is determined. According to this configuration, since the rotor of the brushless motor that generates the steering force in the automatic steering mode rotates concentrically with the steering shaft, the structure is compact. Further, since a value corresponding to a change in the rotation angle of the steering shaft on the steering wheel side can be obtained in time series by the detector of the rotation angle of the rotor, a dedicated detector is not required. Also, from the detector of the rotation angle of the rotor and the output of the second detector,
Since a torque corresponding to the additional steering force is obtained, a dedicated torque sensor is not required.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

The rack and pinion type steering apparatus 1 shown in FIG. 1 transmits a steering force generated by a driver from a steering wheel H to a wheel W via a steering shaft.
To communicate. Further, a steering force generated by a brushless motor 50 described later is transmitted to the wheels W via a steering shaft.

The steering shaft has an input shaft 2 connected to the steering wheel H and an output shaft 4 connected to the input shaft 2 via a torsion bar 3. The torsion bar 3 is connected to the input shaft 2 via a pin 5 and to the output shaft 4 via a serration 6. A pinion 7 is formed on the output shaft 4, and wheels W are connected to each end of the rack 8 that meshes with the pinion 7. The input shaft 2 is connected to a motor housing 10c via a sleeve 2a and a bearing 9 integrated on the outer periphery.
And is supported by the output shaft 4 via a bush 11. The output shaft 4 is supported by the rack housing 10b via bearings 12 and 13. The rack housing 10b and the motor housing 10c are integrated via a valve housing 10a.

The input shaft 2 is rotated by a steering torque based on a steering force. The rotation of the input shaft 2 is transmitted to a pinion 7 via a torsion bar 3 and an output shaft 4.
Is transmitted to The rack 8 moves in the axial direction by the rotation of the pinion 7. The wheels are steered by the movement of the rack 8. At this time, the input shaft 2 on the steering wheel side and the output shaft 4 on the wheel W side of the steering shaft are elastically rotated relative to the coaxial center by the torsion bar 3 being elastically twisted according to the steering torque. I do.

Incidentally, oil seals 14, 15 are provided between the input / output shafts 2, 4 and the valve housing 10a. Further, a support yoke 16 for supporting the rack 8 is provided, and the support yoke 16 is pressed against the rack 8 by the elastic force of a spring 17.

A hydraulic cylinder (hydraulic actuator) 18 for generating a steering assist force is provided. The hydraulic cylinder 18 has a cylinder tube constituted by a rack housing 10b and a piston 20 integrated with the rack 8, and a first oil chamber 21 and a second oil chamber 22 partitioned by the piston 20. Have.

Each of the oil chambers 21 and 22 is connected to a rotary hydraulic control valve 23 that operates based on a steering force, and the control valve 23 controls the hydraulic pressure of the pressure oil supplied from the pump 37 to the hydraulic cylinder 18. As a result, a steering assist force is generated.

That is, the control valve 23 is a cylindrical first valve.
The first valve member 24 includes a valve member 24 and a second valve member 25 that is coaxially rotatably inserted into the first valve member 24. The first valve member 24 is inserted into the valve housing 10a so as to be relatively rotatable, and is attached to the output shaft 4 via a pin 26 so as to be rotatable therewith. The second
The valve member 25 is integrally formed on the outer periphery of the input shaft 2 and rotates together with the input shaft 2. Thereby, the first valve member 24 and the second valve member 25 are
When the torsion bar 3 is twisted in accordance with the steering torque transmitted by the steering shaft, the torsion bar 3 elastically rotates relatively. Hydraulic cylinder 1 according to the relative rotation amount
The hydraulic pressure of the pressure oil supplied from the pump 37 to 8 is controlled.

That is, as shown in FIG. 2, a plurality of recesses along the axial direction are formed on the inner periphery of the first valve member 24 and the outer periphery of the second valve member 25 at equal intervals in the circumferential direction. The first valve member-side concave portion includes a right steering concave portion 27 and a left steering concave portion 28 which are located at equal intervals in the circumferential direction. The second valve member side recess is composed of a pressure oil supply recess 29 and a pressure oil discharge recess 30 which are located at equal intervals in the circumferential direction. Each right steering recess 27 and each left steering recess 28 are alternately arranged in the circumferential direction, and each pressure oil supply recess 29 and each pressure oil discharge recess 30 are alternately arranged in the circumferential direction.

Each right steering recess 27 is provided with a first valve member 2.
4 and the first flow passage 31 formed in the valve housing 1
0a from the first port 32 formed in the hydraulic cylinder 1
8 to the first oil chamber 21.

Each left steering recess 28 is provided with a first valve member 2.
2 and the second flow path 33 formed in the valve housing 1
0a from the second port 34 formed in the hydraulic cylinder 1
8 to the second oil chamber 22.

Each of the recesses 29 for supplying pressure oil is provided with a third passage 35 formed in the first valve member 24 and the valve housing 1.
It communicates with a pump 37 via an inlet port 36 formed at 0a.

Each of the recesses 30 for discharging pressure oil is provided with a first discharge passage 38 formed in the second valve member 25, a passage 47 between the input shaft 2 and the inner and outer circumferences of the torsion bar 3, and a discharge formed in the valve housing 10a. Tank 4 via port 40
Lead to 1.

Thus, the oil chambers 21 and 22 of the hydraulic cylinder 18 and the pump 37 are connected via the inter-valve oil passage 42 formed between the inner and outer circumferences of the first valve member 24 and the second valve member 25. Connected. The pump 37 is driven by a motor 64, and can be configured by, for example, a vane pump or a gear pump that discharges pressure oil at a flow rate corresponding to the rotation speed of the pump driving motor 64. In the inter-valve oil passage 42, between the first valve member-side concave portion and the second valve member-side concave portion, there are throttle portions A, B, C, and D whose opening degree changes due to the relative rotation of the two valve members 24 and 25. Is done. Each aperture section A,
By changing the opening of B, C, and D according to the steering torque,
The hydraulic pressure acting on the hydraulic cylinder 18 is controlled. FIG.
Shows the hydraulic circuit.

FIG. 2 shows the relative positions of the two valve members 24 and 25 at the straight steering position where steering is not performed. In this state, each pressure oil supply recess 29 and each pressure oil discharge recess 29 are provided. The apertures of the throttle portions A, B, C, and D between 30 and 30 are constant.

When the vehicle is steered rightward from the straight steering position, each right steering recess 27 and each hydraulic oil supply are provided in accordance with the relative rotation of the two valve members 24 and 25 due to the torsion of the torsion bar 3 according to the steering torque. The opening degree of the throttle portion A between the concave portion 29 and the opening degree of the throttle portion B between each left steering concave portion 28 and each pressure oil discharging concave portion 30 are increased, and each left steering concave portion 28 is formed.
The opening degree of the throttle portion C between the pressure oil supply concave portion 29 and the throttle portion D between the right steering concave portion 27 and the pressure oil discharge concave portion 30 becomes smaller. Thereby, pressure oil according to the steering torque is supplied from the pump 37 to the first oil chamber 21,
Oil is recirculated from the second oil chamber 22 to the tank 41, and a steering assisting force to the right of the vehicle acts on the rack 8.

When the vehicle is steered to the left from the straight steering position, the opening of each of the throttles A, B, C, and D changes in reverse to the case where the vehicle is steered to the right. Acts on the rack 8.

As shown in FIG. 1, a three-phase brushless motor 50 is provided as an actuator for generating a steering force. The brushless motor 50 includes a rotor 51 mounted inside the motor housing 10c so as to rotate concentrically with the input shaft 2 via the sleeve 2a, and a stator mounted on the motor housing 10c so as to surround the rotor 51. 52, and a detector for detecting the rotation angle of the rotor 51. The detector includes a first resolver 53 having a rotor 53a integrated with the input shaft 2 via a sleeve 2a and a stator 53b attached to the motor housing 10c. The control valve 23 is disposed closer to the wheel W than the brushless motor 50 is.

On the wheel W side of the control valve 23,
A second resolver 65 for detecting the rotation angle of the steering shaft is provided. The second resolver 65 has a rotor 65a integrated with the output shaft 4, and a stator 65b attached to the rack housing 10b.

The stator 52 of the brushless motor 50
And the stator 53b of the first resolver 53 are connected to the control device 61. The control device 61 includes a mode changeover switch 62, an input device 63, the pump driving motor 64, and a stator 65b of the second resolver 65.
And a plurality of obstacle detection sensors 6 attached to the vehicle body
6, 67, 68, 69 and a vehicle speed sensor 70 are connected.

By operating the mode changeover switch 62, it is possible to switch the steering mode of the vehicle between the automatic steering mode and the normal steering mode. In the automatic steering mode, the brushless motor 50 generates a steering force based on a command signal from the control device 61,
In the normal steering mode, the driver generates a steering force.

The input device 63 includes, for example, a beacon signal transmitted from a transmitter provided on a traveling road or a guardrail, an alarm signal for notifying a danger of collision transmitted from a transmitter provided in another vehicle, or the like. , A guidance signal such as a detection signal of a traveling line on the road is input. When the guidance signal is input from the input device 63 in the automatic steering mode, the control device 61
Outputs a drive current of the brushless motor 50 as a command signal for eliminating a deviation between a target steering angle necessary for steering the vehicle according to the guidance signal and an actual steering angle input from the first resolver 53. I do. The steering force generated by the brushless motor 50 is transmitted to the wheels W via the steering shaft, similarly to the steering force generated by the driver in the normal steering mode.

In addition, the control device 61 determines the torque transmitted by the steering shaft based on the added steering force as a value corresponding to the added steering force other than the steering force generated by the brushless motor 50 during the automatic steering. Is obtained from the outputs of the first resolver 53 and the second resolver 65.

That is, the input shaft 2 and the output shaft 4 are relatively resiliently rotated about a coaxial center when the torsion bar 3 is elastically twisted according to the steering torque. Therefore, the difference between the rotation angle of the input shaft 2 detected by the first resolver 53 and the rotation angle of the output shaft 4 detected by the second resolver 65 corresponds to the torque transmitted by the steering shaft.

FIG. 4A shows the relationship between the output of the first resolver 53 and the rotation angle of the input shaft 2. The control device 61 stores the output Eao of the first resolver 53 when the torque transmitted by the steering shaft is zero and the steering angle is zero as a reference output at the reference position P of the input shaft 2. The control device 61 controls the first resolver 5
3 and the reference output Eao, the rotor 5
1 and the rotation angle of the steering shaft on the steering wheel H side are obtained in time series.

FIG. 4B shows the relationship between the output of the second resolver 65 and the rotation angle of the output shaft 4. The control device 61 stores the output Ebo of the second resolver 65 when the torque transmitted by the steering shaft is zero and the steering angle is zero as a reference output at the reference position P of the output shaft 4. The control device 61 controls the second resolver 6
From the difference between the actual output of No. 5 and the reference output Ebo, the rotation angle of the steering shaft on the wheel W side is obtained in time series.

Since the outputs of the resolvers 53 and 65 have a sine waveform, the rotation angles may be different even if the outputs are the same. Therefore, the reference output Eao of the first resolver 53
And the reference output Ebo of the second resolver 65 are different from each other. Thus, by comparing the outputs of the resolvers 53 and 65 with each other, the rotation angle can be accurately obtained, and a dedicated detector for obtaining the reference position is not required, so that the cost can be reduced.

In order to cope with the case where the rotation angle of the steering shaft exceeds one cycle of the sine waveform of the output of each of the resolvers 53 and 65, the control device 61 controls each of the resolvers 5 and 65.
A pulse signal is generated for each cycle of the sine waveform of the output of each of the resolvers 53 and 65, and the actual output of each of the resolvers 53 and 65 and the reference output Ebo. Is added to the rotation angle obtained from the difference between

The controller 61 calculates the total torque transmitted by the steering shaft from the difference between the rotation angle of the steering shaft obtained by the first resolver 53 and the rotation angle of the steering shaft obtained by the second resolver 65. The brushless motor 5 is determined from the total torque transmitted by the steering shaft.
By subtracting the torque due to the steering force generated by 0,
A torque based on the additional steering force is determined. The torque due to the steering force generated by the brushless motor 50 can be obtained from the drive current value of the brushless motor 50.

The controller 61 determines whether the additional steering force is applied by the driver or externally to the vehicle. That is, when the change in the rotation angle of the steering shaft on the steering wheel H side precedes the change in the rotation angle on the wheel W side, it is determined that the additional steering force has been added by the driver. On the other hand, when the change in the rotation angle on the wheel W side of the steering shaft precedes the change in the rotation angle on the steering wheel H side, it is determined that the additional steering force has been externally applied to the vehicle. In the present embodiment, the rotational angular velocity of the steering shaft on the steering wheel H side and the rotational angular velocity on the wheel W side are compared, and it is determined that a change in the rotational angle precedes the larger rotational angular velocity.

The control device 61 determines whether there is a possibility of collision between the vehicle and an obstacle detected in the steering direction by the additional steering force. In the present embodiment, as shown in FIG. 5, the obstacle detection sensors 66, 67, 68, 69
It detects obstacles such as other vehicles and guardrails on the left and right sides and the left and right sides of the vehicle V. A transmitter that emits a radar wave such as a laser or an ultrasonic wave from the vehicle, and a receiver of the radar wave , And an amplifier for the received radar wave. The control device 61 calculates the distance to the obstacle based on the time difference between the transmission and reception of the radar wave, and determines the steering direction of the additional steering force based on the signals from the resolvers 53 and 65. If an obstacle is detected within a predetermined distance in the steering direction, it is determined that there is a possibility of collision.

The control device 61 switches from the automatic steering mode to the normal steering mode when the additional steering force is added by the driver and the value corresponding to the additional steering force is equal to or more than the first set value. Further, the additional steering force is added by the driver, and a value corresponding to the additional steering force is less than the first set value and equal to or more than the second set value, and the obstacle can collide with the vehicle. When there is no such condition, the mode is switched from the automatic steering mode to the normal steering mode.

The flowchart of FIG.
1 shows a control procedure for switching the steering mode according to No. 1. The control device 61 first determines whether or not the current time is in the automatic steering mode (step 1). In the automatic steering mode, the automatic steering is performed by driving the brushless motor 50 (step 2). At the time of the automatic steering, it is determined whether the additional steering force other than the steering force generated by the brushless motor 50 is applied by the driver or a disturbance externally applied to the vehicle (step 3). If the additional steering force is a disturbance, automatic steering is continued. When the additional steering force is added by the driver, the torque T transmitted by the steering shaft based on the additional steering force
Is greater than or equal to the first set value T1 (step 4). If the torque T transmitted by the steering shaft is less than the first set value T1, the second set value T2
It is determined whether or not this is the case (step 5). Second set value T2
If less, automatic steering is continued. If the torque T transmitted by the steering shaft is less than the first set value T1 and not less than the second set value T2, it is determined whether there is a possibility of collision with an obstacle (step 6). If there is a possibility of collision with an obstacle, automatic steering is continued. In step 4, when the torque T transmitted by the steering shaft based on the additional steering force is equal to or larger than the first set value T1, that is, when the driver is exerting a large steering force against the automatic steering, the emergency Since the steering intention is considered to be large, the brushless motor 5
The automatic steering is released by interrupting the drive current of 0 (step 7). If there is no possibility of collision with an obstacle in step 6, the driver's intention for emergency steering is not high, but there is no danger even if automatic steering is canceled.
Release automatic steering. Alternatively, if the automatic steering mode is not set in step 1, the automatic steering is canceled. When the automatic steering is released, the mode is switched to the normal steering mode.
The first set value T1 can be set based on the steering force generated by the driver when the urgency of the steering by the driver is high. The second set value T2 can be set based on a steering force generated by the driver when the driver indicates a steering intention.

The controller 61 sets the rotational speed of the pump drive motor 64 to the steering assist speed when steering assist is required, and to the standby speed when steering assist is not required. That is, if the steering torque is equal to or greater than the set value, the control device 61 outputs an instruction signal for setting the rotation speed of the pump driving motor 64 to the steering assist speed. The steering assist speed is a speed set in advance so that the flow rate of the pressure oil sent from the pump 37 becomes a flow rate necessary for the steering assist. The steering assist speed changes according to the vehicle speed detected by the vehicle speed sensor 70. That is, the steering assist speed is determined so that the steering assist force is increased at a low vehicle speed to improve the turning performance of the vehicle, and at a high vehicle speed, the steering assist force is reduced to improve the running stability of the vehicle. Thus, a steering assist force is generated in both the normal steering mode and the automatic steering mode. If the value of the steering torque is less than the set value, the control device 61 outputs an instruction signal for setting the rotation speed of the pump driving motor 64 to the standby speed. The standby speed is a preset speed smaller than the steering assist speed, and is set to zero in the present embodiment, but may be a value larger than zero. Thereby, energy saving can be achieved.

According to the above configuration, it is possible to switch to the normal steering mode without changing the actual steering angle only by applying the steering force by the driver during the automatic steering.
As a result, it is possible to quickly switch from the automatic steering mode to the normal steering mode in an emergency or the like. In addition, since it is determined whether the steering force applied during the automatic steering is applied by the driver or externally to the vehicle, it is possible to prevent accidental switching from the automatic steering mode to the normal steering mode due to disturbance. Can be prevented. When the value T corresponding to the additional steering force of the driver during the automatic steering is equal to or larger than the first set value T1, even if there is a possibility that the obstacle and the vehicle V may collide in the steering direction due to the additional steering force, the automatic The steering mode is switched to the normal steering mode. As a result, when the need for steering by the driver increases during automatic steering, for example, when the driver applies a large steering force to avoid an obstacle in front, another obstacle in the steering direction due to the additional steering force is generated. Even if there is a possibility of collision with an object, a large accident or the like can be prevented by steering the driver to avoid an obstacle ahead. The value T corresponding to the driver's additional steering force during the automatic steering is the first set value T.
If it is less than 1 and becomes equal to or more than the second set value T2, the automatic steering mode is switched to the normal steering mode if there is no possibility of collision between the vehicle and the obstacle in the steering direction by the additional steering force. This makes it possible to ensure safety when the driver switches to the normal steering mode by applying a steering force during automatic steering. Whether the additional steering force other than the steering force generated by the brushless motor 50 during the automatic steering precedes the change in the rotation angle of the steering shaft on the steering wheel H side or the change in the rotation angle on the wheel W side. , It is possible to reliably determine whether the addition is made by the driver or from outside the vehicle. Since the rotor 51 of the brushless motor 50 that generates a steering force in the automatic steering mode rotates concentrically with the steering shaft, the response to the control by the control device 61 is quick, resulting in a compact and simple structure. In addition, the first resolver 53 of the brushless motor 50 can determine a value corresponding to a change in the rotation angle of the steering shaft on the steering wheel H side in a time series, so that a dedicated detector is not required. In addition, the first resolver 53 and the second resolver 65
Since the torque corresponding to the additional steering force is obtained from the output of (1), a dedicated torque sensor is not required. Thereby, the structure can be made simple and compact, and the manufacturing cost can be reduced. Further, each resolver 53, 65 includes a stator 53b,
Since the output can be adjusted only by rotating the rotors 53a and 65a with respect to the rotor 65b, assembly is easy.

FIG. 7 shows a flowchart of a first modification of the present invention. The difference from the flowchart of the above embodiment is that
When the torque T transmitted by the steering shaft based on the additional steering force of the driver is less than the first set value T1 and is equal to or more than the second set value T2, if there is a possibility of collision with an obstacle, automatic steering is performed. It is canceled and switched to the normal steering mode (step 8), then the steering is suppressed (step 9), and the steering suppression is continued until the possibility of collision disappears. In this case, the steering can be suppressed by using the brushless motor 50 to apply a steering force in a direction opposite to the steering direction by the additional steering force by the driver, or to reduce the rotation speed of the pump drive motor 64. Others are the same as the above embodiment. The value T corresponding to the steering force of the driver is less than the first set value T1 and the second set value T2
In this case, the urgency of steering by the driver is low. Therefore, if there is a possibility that the obstacle will collide with the vehicle in the steering direction due to the additional steering force, the driver switches from the automatic steering mode to the normal steering mode and suppresses the driver's steering, so that the driver recognizes the presence of the obstacle. Can be done.

FIGS. 8 and 9 show a second modification of the present invention.
The difference from the above embodiment is that, instead of the second resolver 65,
The torque sensor 107 is connected to the brushless motor 50 and the control valve 2.
3 is provided.

The torque sensor 107 includes first and second detection coils 13 held by the valve housing 10a.
3, 134, a first detection ring 136 made of a magnetic material, which is rotatably connected to the first valve member 24 of the control valve 23 via a connection member 140, and is rotatably connected to the input shaft 2. And a second detection ring 137 made of a magnetic material. One end face of the first detection ring 136 and one end face of the second detection ring 137 are arranged so as to face each other, and teeth 136a and 137a are respectively provided on the opposing end faces of the detection rings 136 and 137 along the circumferential direction. A plurality is provided. The other end of the second detection ring 137 is a small diameter portion 137b having an outer diameter smaller than the one end. The first detection coil 133 is disposed so as to cover a space between the first detection ring 136 and the second detection ring 137, and the second detection coil 134 is disposed so as to cover the second detection ring 137. , 134 are connected to a signal processing circuit 141 formed on a substrate attached to the valve housing 10a. In the signal processing circuit 141, the first detection coil 133 is connected to the oscillator 146 via the resistor 145, and the second detection coil 134 is connected to the resistor 147.
Is connected to the oscillator 146 via the
3 and 134 are connected to the differential amplifier circuit 148. Thereby, the torsion bar 3 is twisted by the torque transmitted by the steering shaft, and the two detection rings 136, 1
When the relative rotation of 37 is elastic, each detection ring 136,
The facing area of the 137 teeth 136a, 137a changes.
Due to the change in the area, the magnetic resistance of the first detection coil 133 with respect to the magnetic flux generated between the opposing teeth 136a and 137a changes. Therefore, the output of the first detection coil 133 changes according to the change, and the output corresponds. The detected transmission torque is detected. The torque detection signal is transmitted to the controller 61
Is input to Further, the second detection coil 134 faces the small diameter portion 137b of the second detection ring 137. The outer diameter of the small diameter portion 137b is in a state where the steering resistance does not act,
The magnetic resistance to the magnetic flux generated by the second detection coil 134 and the magnetic resistance to the magnetic flux generated by the first detection coil 133 are set to be equal. As a result, the output fluctuation of the first detection coil 133 due to the temperature fluctuation becomes equal to the output fluctuation of the second detection coil 134 due to the temperature fluctuation. Compensated. Also, instead of the oil seal 14 between the input shaft 2 and the valve housing 10a in the above embodiment, an oil seal 114 is provided between the connecting member 140 and the input shaft 2 and between the connecting member 140 and the valve housing 10a. Is arranged.
Other parts are the same as those of the above embodiment, and the same parts are denoted by the same reference numerals.

According to the second modification, during automatic steering,
The torque transmitted from the steering shaft is obtained by the torque sensor 107 as a value corresponding to the steering force applied in addition to the steering force generated by the brushless motor 50. The torque detected by the torque sensor 107 corresponds to the rotation angle of the steering shaft on the wheel W side. The control device 61 obtains the torque detected by the torque sensor 107 in time series. The control device 61
When the change in the rotation angle of the steering shaft on the steering wheel H side obtained by the first resolver 53 precedes the change in the torque detected by the torque sensor 107, it is determined that the additional steering force has been added by the driver. On the other hand, when the change in the torque detected by the torque sensor 107 precedes the change in the rotation angle on the steering wheel H side, it is determined that the additional steering force has been externally applied to the vehicle. In the second modified example, since the control valve 23 and the torque sensor 107 share the torsion bar 3, the rigidity of the torsion bar 3 can be prevented from lowering.

FIG. 10 shows a third modification of the present invention. The difference from the second modification is that a brush-equipped motor 150 is used instead of the brushless motor 50, and the rotation of the motor 150 is transmitted to the input shaft 2 via an electromagnetic clutch 151 and a speed reduction mechanism 152. Further, instead of the first resolver 53, a steering angle sensor 153 is provided between the steering wheel H and the speed reduction mechanism 152. In this case, the automatic steering mode is released by interrupting the rotation transmission by the electromagnetic clutch 151, or by interrupting the rotation transmission by the electromagnetic clutch 151 and stopping the driving of the motor 150. Further, the rotation angle of the steering shaft on the steering wheel H side is obtained in a time series based on the output of the steering angle sensor 153. Others are the same as the second modification.

FIG. 11 shows a fourth modification of the present invention. The difference from the second modification is that the steering assist force is applied using an electric actuator instead of a hydraulic actuator. That is, based on a signal from the control device 61, the output of the motor 160 is output via the electromagnetic clutch 161 and the speed reduction mechanism 162 so that the steering assist force according to the torque detected by the torque sensor 107 can be applied.
To communicate. Others are the same as the second modification.

It should be noted that the present invention is not limited to the above-described embodiment and modifications. For example, the value corresponding to the additional steering force is the torque transmitted by the steering shaft based on the additional steering force in the above embodiment. However, the value is not particularly limited. For example, the change acceleration of the torque or the torque May be used as the time integration value. Further, a torque sensor for detecting torque transmitted by the steering shaft may be provided between the steering wheel and the steering force generating actuator. In this case, the torque transmitted by the steering shaft based on the additional steering force can be directly obtained without subtracting the torque generated by the actuator from the total torque transmitted by the steering shaft as described above.

[0056]

According to the present invention, in a vehicle steering apparatus capable of selecting between an automatic steering mode and a normal steering mode, when an emergency situation occurs in the automatic steering mode, the driver is not affected by disturbance and is not affected by disturbance. You can quickly switch to normal steering mode according to your intentions,
Further, the danger of collision with an obstacle can be avoided, and the structure can be made compact and simple to reduce the cost.

[Brief description of the drawings]

FIG. 1 is a sectional view of a steering device for a vehicle according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a hydraulic circuit diagram of the steering device of the vehicle according to the embodiment of the present invention.

FIG. 4 is a diagram showing a relationship between an output of a first resolver and (2) a relationship of an output of a second resolver with respect to a rotation angle of a steering shaft of the steering device of the vehicle according to the embodiment of the present invention.

FIG. 5 is a plan view for explaining the arrangement of an obstacle detection sensor of the vehicle according to the embodiment of the present invention.

FIG. 6 is a flowchart showing a control procedure of the vehicle steering device according to the embodiment of the present invention.

FIG. 7 is a flowchart showing a control procedure of a steering device of a vehicle according to a first modification of the present invention.

FIG. 8 is a sectional view of a steering device for a vehicle according to a second modification of the present invention.

FIG. 9 is an output processing circuit diagram of a torque sensor of a steering device for a vehicle according to a second modification of the present invention.

FIG. 10 is a sectional view of a steering device for a vehicle according to a third modification of the present invention.

FIG. 11 is a configuration explanatory view of a steering device of a vehicle according to a fourth modified example of the present invention.

[Explanation of symbols]

 2 input shaft 4 output shaft 18 hydraulic cylinder 23 control valve 50 brushless motor 51 rotor 52 stator 53 first resolver 61 control device 65 second resolver 66, 67, 68, 69 obstacle detection sensor 107 torque sensor 150 motor 153 steering angle sensor 160 Motor H Steering wheel V Vehicle W Wheel

Continuation of front page (72) Inventor Naoki Maeda Koyo Seiko Co., Ltd., 3-5-8 Minamisenba, Chuo-ku, Osaka-shi, Osaka

Claims (5)

[Claims] A steering apparatus for a vehicle capable of switching a steering mode between an automatic steering mode in which an actuator generates a steering force based on a command signal from a control device and a normal steering mode in which a driver generates a steering force. Means for detecting a value corresponding to a steering force applied in addition to the steering force generated by the actuator during the automatic steering, and whether the additional steering force is applied by a driver or externally to the vehicle. And a means for switching from the automatic steering mode to the normal steering mode when the additional steering force is added by the driver and the value corresponding to the additional steering force is equal to or greater than a set value. A steering device for a vehicle, comprising: 2. A means for determining whether there is a possibility of collision between a vehicle and an obstacle detected in a steering direction based on the additional steering force, the additional steering force being added by a driver, and Means for switching from the automatic steering mode to the normal steering mode when the corresponding value is greater than or equal to the first set value; and the additional steering force is added by the driver, and the value corresponding to the additional steering force is the first setting. The system according to claim 1, further comprising: means for switching from the automatic steering mode to the normal steering mode when the value is less than the value and not less than the second set value and there is no possibility of collision between the obstacle and the vehicle. Vehicle steering device. 3. The vehicle according to claim 1, wherein the additional steering force is added by a driver, and a value corresponding to the additional steering force is less than the first set value and greater than or equal to a second set value. 3. The vehicle steering apparatus according to claim 2, further comprising means for switching from the automatic steering mode to the normal steering mode and suppressing a driver's steering when there is a possibility of collision. 4. A steering force generated by a driver is transmitted from a steering wheel to a wheel via a steering shaft. As a value corresponding to the additional steering force, a torque transmitted by the steering shaft based on the additional steering force is obtained. The steering wheel side and the wheel side of the steering shaft are relatively rotatable elastically according to the torque, and a value corresponding to the rotation angle of the steering shaft on the steering wheel side is obtained in time series. Means, and means for obtaining a value corresponding to the rotation angle of the steering shaft on the wheel side in time series are provided, and a change in the rotation angle of the steering shaft on the steering wheel side is determined by the change of the rotation angle on the wheel side. Prior to the change, it is determined that the additional steering force was added by the driver. When the change in the rotation angle on the wheel side of the steering shaft precedes the change in the rotation angle on the steering wheel side, it is determined that the additional steering force is externally applied to the vehicle. A steering device for a vehicle according to any one of the preceding claims. 5. The actuator according to claim 1, wherein the actuator is a brushless motor having a rotor concentrically rotating with the steering shaft, a stator surrounding the rotor, and a detector for detecting a rotation angle of the rotor. A value corresponding to the rotation angle of the steering shaft on the steering wheel side is obtained in time series by the detector, and the hydraulic actuator for generating the steering assist force and the hydraulic pressure of the hydraulic oil supplied from the pump to the hydraulic actuator are obtained. A control valve for controlling the torque according to the torque transmitted by the steering shaft, the control valve being disposed closer to the wheel than the brushless motor, and having a rotation angle of the steering shaft closer to the wheel than the control valve. A second detector is provided, and the second detector causes the steering shuffle to be provided. A value corresponding to the rotation angle of the steering wheel on the wheel side is obtained in a time series, and the rotation angle of the steering shaft obtained by the detector of the rotation angle of the rotor and the rotation angle of the steering shaft obtained by the second detector are obtained. The vehicle steering apparatus according to claim 4, wherein the torque is obtained from a difference between: