JP4543599B2 - Automatic vehicle evacuation device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an automatic vehicle retracting device that stops a vehicle within a predetermined retreat area when a failure occurs in a steering system.
[0002]
[Prior art]
Japanese Patent Application Laid-Open No. 9-161196 discloses an automatic driving control device that performs autonomous running by controlling the speed and steering angle of a vehicle based on information from various sensors. And when a failure occurs in such automatic driving control, it is disclosed that automatic steering control is performed on the traveling vehicle to retract the vehicle from the traveling lane.
[0003]
[Problems to be solved by the invention]
Further, when a failure occurs in the automatic driving control as described above, the automatic driving control is stopped, the steering system between the steering handle and the wheel is mechanically directly connected, and the rotation of the steering handle and the wheel It is also conceivable to switch to normal manual steering where the steering is mechanically linked.
[0004]
However, when a failure occurs in sensors, motors, hydraulic systems, etc. provided in the steering system for some reason during traveling, the above-described automatic steering control effect may not be sufficiently exhibited. In addition to the failure of such sensors, etc., in the case of a failure in the steering mechanism such as the rotation operation of the steering shaft being locked, or in the steering mechanism such that the wheel turning operation is disabled When a failure occurs, it may be difficult to change the course of the vehicle even when switching to manual steering as described above.
[0005]
In addition, when a failure occurs in a series of steering systems composed of a steering mechanism, a steering mechanism, a sensor, a motor, and the like in this way, the vehicle is forcibly decelerated and the vehicle is immediately Although it is conceivable to stop the vehicle, depending on the position where the vehicle finally stops, it may be an obstacle for the vehicle traveling around.
[0006]
The present invention has been made paying attention to such problems, and its purpose is to enable a certain degree of control of the direction of travel of the vehicle even in the event of a failure in the steering system, and to make it more suitable. An object of the present invention is to provide an automatic vehicle evacuation device capable of stopping a vehicle.
[0007]
[Means for Solving the Problems]
Accordingly, the vehicle automatic retraction device according to claim 1 is a vehicle automatic retraction device that stops the vehicle in a predetermined retraction area, and is capable of controlling the magnitude of the brake force applied to the predetermined wheel. And a retraction control means for controlling the operation of the brake control mechanism and stopping the vehicle in a predetermined retraction area when a failure occurs in the steering system that steers the wheels in conjunction with the steering wheel operation. .
[0008]
The braking control mechanism includes a type having a generation source that generates a braking force regardless of the driver's braking operation, and a braking force generated in conjunction with the driver's braking operation without such a generation source. Both types that control the distribution state when distributing to predetermined wheels are included.
[0009]
Assuming that the steering angle of the wheel is fixed while the vehicle is traveling, it is assumed that the steering system has failed. As an example, in this state, if a larger braking force (braking force) is applied to the right wheel than the left wheel, the vehicle will tend to turn clockwise, and the vehicle will move to the right with respect to the previous traveling direction. The course of the vehicle changes. Further, when a greater braking force is applied to the left wheel than to the right wheel, the vehicle tends to turn counterclockwise, and the course of the vehicle changes from the left with respect to the previous traveling direction. By using such an action, the retraction control means controls the operation of the braking control mechanism when a failure occurs in the steering system, controls the traveling direction of the vehicle, and stops the vehicle in a predetermined retraction area. .
[0010]
According to a second aspect of the present invention, there is provided the vehicle automatic evacuation device according to the first aspect, wherein the evacuation control means defines a stop region where the vehicle can be stopped by the operation control of the brake control mechanism. Based on the stop area calculation means that calculates based on, the peripheral information acquisition means for obtaining the situation around the course of the vehicle, the calculation result of the stop area calculation means and the peripheral information obtained by the peripheral information acquisition means, Based on the selection means for selecting the evacuation area as an area for stopping the vehicle in the stop area, and the positional relationship between the evacuation area selected by the selection means and the running vehicle, the operation control of the braking control mechanism is performed. And a control means.
[0011]
When stopping the vehicle by controlling the amount of braking force applied to the wheels, the stop area where the vehicle can be stopped is ascertained based on the running state of the vehicle, such as the immediately preceding vehicle speed and wheel turning angle. can do. Therefore, first, a stop area in which the vehicle can be stopped is calculated by the stop area calculation means based on the traveling state of the vehicle. Then, the situation around the course of the vehicle, such as the road bending state, the width of the road, the size of the shoulder, and the presence or absence of an intersection, is grasped by a peripheral information acquisition means such as an in-vehicle navigation system, road-to-vehicle communication, or vehicle-to-vehicle communication. be able to. Based on the peripheral information and the stop area obtained in this way, the selection means selects the above-described retreat area as an area where the vehicle can be retreated suitably in the stop area. Then, the control means controls the operation of the braking control mechanism at the predetermined wheel according to the positional relationship between the retreat area and the traveling vehicle, and stops the vehicle within the predetermined retreat area.
[0012]
According to a third aspect of the present invention, there is provided the automatic vehicle evacuation device according to the first aspect, wherein the evacuation control means controls the operation of the braking control mechanism in accordance with the steering operation state of the driver. Features.
[0013]
Even if the steering system that steers the wheels fails, if the steering wheel can be rotated, the direction in which the driver wants to change the course of the vehicle is determined based on the steering angle. It is also possible to grasp. Even when the steering wheel is locked, it is possible to know the direction the driver wants to change the course of the vehicle based on the steering torque applied to the steering wheel. It is. Therefore, the evacuation control means detects the direction in which the driver desires to change the course of the vehicle based on the steering operation state of the driver, and based on the detection result, the braking control mechanism. Is controlled to control the traveling direction of the vehicle during the evacuation travel.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.
[0015]
FIG. 1 shows a steering system including a retraction control device according to the first embodiment.
[0016]
One end of a steering shaft 12 is connected to the steering handle 10, and the other end side of the steering shaft 12 is connected to a rack and pinion type gear device 13. In the gear device 13, the rotational movement of the steering shaft 12 is performed. Is converted into a linear motion of the rack shaft 14, and the wheel W is steered by the operation of the rack shaft 14.
[0017]
The rack shaft 14 includes an electric assist device 15 that applies steering assist force, and operation control is performed so as to generate assist force according to the steering torque.
[0018]
Further, the steering shaft 12 has a transmission ratio variable mechanism 16 in the middle, and the input shaft 12A on the steering handle 10 side and the output shaft 12B on the gear device 13 side are connected via the transmission ratio variable mechanism 16. is doing.
[0019]
The transmission ratio variable mechanism 16 includes a predetermined gear mechanism that connects the input shaft 12A and the output shaft 12B in a relatively rotatable state, and a drive motor that drives the gear mechanism, and rotationally drives the drive motor. Thus, the output shaft 2B rotates relative to the input shaft 12A, and the transmission ratio of the rotation amount between the input shaft 12A and the output shaft 12B is changed by controlling the operation of the drive motor. A control system is configured. A steering angle sensor 310 for detecting the steering angle of the steering handle 10 and a torque sensor 311 for detecting a steering torque applied to the steering handle are provided for the input shaft 12A.
[0020]
In addition, in the hydraulic pressure control system that supplies the hydraulic fluid to the brake device of each of the four wheels, separately from the operation of the brake pedal 20 by the driver, the hydraulic pressure of the hydraulic fluid supplied to each wheel cylinder 21 is controlled. A brake actuator 200 is provided, and a hydraulic control system including the brake actuator 200 is schematically shown in FIG. The brake actuator 200 is a mechanism that can control the hydraulic pressure independently for each brake device of each wheel, and FIG. 2 representatively shows the configuration of the brake actuator 200 for one wheel. The same configuration is applied to the wheels.
[0021]
The pipe line 201 connecting the master cylinder 30 and the wheel cylinder 21 is provided with a shut-off valve (non-energized: valve open) 210, which is closed when the hydraulic pressure control of the hydraulic fluid is executed. The pipe line 201 between the cylinder 30 and the wheel cylinder 21 is blocked. Further, the pipe line 201 closer to the wheel cylinder 21 than the shutoff valve 210 is provided with a holding valve (non-energized: valve opening) 220, and the holding valve 220 is closed so that the holding cylinder 220 is connected to the wheel cylinder. The hydraulic system on the 21st side can be closed.
[0022]
A pipe line 201 between the holding valve 220 and the wheel cylinder 21 is connected to a reservoir 255 by a pipe line 202, and this pipe line 202 includes a pressure reducing valve (non-energized: valve closed) 230. The communication state of the pipe line 202 can be changed by duty-driving the pressure reducing valve 230 with a binary / state drive control signal in a non-energized state.
[0023]
The hydraulic pump 251 that is rotationally driven by the motor 250 functions as a hydraulic pressure generation source when controlling the braking force separately from the driver's braking operation. The discharge port of the hydraulic pump 251 is connected to the pipe line 203. Through the pipe 201 between the shut-off valve 210 and the holding valve 220. A check valve 252 that prevents the flow of hydraulic fluid in the direction opposite to the discharge direction is provided on the discharge port side of the hydraulic pump 251.
[0024]
On the other hand, the suction port side of the hydraulic pump 251 is connected to the reservoir 255 via the pipe line 204, and a check valve 253 that blocks the flow of hydraulic fluid in the direction opposite to the suction direction is connected to the pipe line 204. 254.
[0025]
The pipe line 204 between the check valves 253 and 254 is connected to the reservoir tank 31 through the pipe line 205, and the hydraulic fluid in the reservoir tank 31 passes through the pipe line 204 to the hydraulic pump 251. Sucked into. In addition, a suction valve (non-energized: valve closed) 240 for opening and closing the pipeline 205 is provided in the middle of the pipeline 205.
[0026]
As described above, the brake actuator 200 including the hydraulic pump 251 and various valve devices is controlled by the retraction control device 100.
[0027]
As shown in FIG. 3, the retraction control device 100 includes the above-described steering angle sensor 310 and torque sensor 311, a wheel speed sensor 312 that detects the rotation state of each wheel W, the current position of the vehicle, and the surrounding roads. It acts on a navigation system 313 for obtaining geographic information, a CCD camera 314 mounted on the front and rear of the vehicle body to obtain the current situation around the vehicle, a stroke sensor 315 for detecting the turning angle of the wheel W as a stroke position of the rack shaft 14, and a wheel cylinder 21. The detection result of each sensor such as a pressure sensor 316, a yaw rate sensor 317, a lateral acceleration sensor 318, and a longitudinal acceleration sensor 319 is detected.
[0028]
The retraction control device 100 is given the determination result of the failure determination unit 320 that determines the failure of the steering system, and the retraction control device 100 determines that the failure has occurred in the steering system. Then, retreat control for stopping the vehicle in a predetermined retreat area is started. The failure determination unit 320 is provided with operation information of each sensor and drive mechanism constituting the steering system such as the various sensors, the transmission ratio variable mechanism 16 and the assist device 15 as described above, and based on these results. Next, a failure of the steering system is determined. As an example of determining that a failure has occurred in the steering system, for example, some failure has occurred in the transmission ratio variable mechanism 16 or the assist device 15, and the operation operation of the steering wheel 10 or the turning operation of the wheel W is in the locked state. The steering wheel state desired by the driver, such as when the steering wheel 10 can be rotated, or when a failure occurs in the steering operation control of the wheel W according to the steering wheel operation. When a situation occurs in which the actual steering state and the actual steering state do not coincide with each other, it is determined that a failure has occurred in the steering system.
[0029]
Note that in what state it is determined that a failure has occurred in the steering system depends on the configuration of the steering system and the design concept, and is not limited to the above-described example.
[0030]
Next, vehicle evacuation control performed by the evacuation control device 100 will be described with reference to the flowchart of FIG. This flowchart is activated by turning on the ignition switch.
[0031]
First, the process proceeds to step 102 (hereinafter, “step” is referred to as “S”) 102, and the vehicle speed V, the steering angle, and the turning angle are read by reading information from each sensor shown in FIG. Various vehicle state quantities indicating the vehicle running state such as the braking state and the turning state are acquired.
[0032]
In subsequent S104, a controllable region (stop region), which is a region where the vehicle can be stopped when the retraction control is started at this time, is calculated based on such a vehicle state quantity. For example, when a larger braking force is applied to the right wheel than to the left wheel, the vehicle tends to turn clockwise, and the course of the vehicle changes from the right with respect to the previous traveling direction. Further, when a greater braking force is applied to the left wheel than to the right wheel, the vehicle tends to turn counterclockwise, and the course of the vehicle changes from the left with respect to the previous traveling direction. Thus, it is possible to control the behavior of the vehicle by applying the braking force control to the predetermined wheel, and the vehicle speed V, the turning angle of the wheel W, the yaw rate, the lateral acceleration, the longitudinal acceleration, etc. at that time can also be controlled. In addition, it is possible to grasp the controllable region by calculation or experimentally.
[0033]
As an example, as shown in FIG. 5A, when the vehicle A is traveling on a straight road with two lanes on one side, the area between the dotted lines L1 and L2 is calculated as the controllable ranges L1 to L2. The
[0034]
In subsequent S106, the surrounding road shape and the current position N of the vehicle are acquired from the in-vehicle navigation system 313. As is well known, the navigation system 313 uses each of the current position N of the vehicle and the surrounding road shape based on map data prepared in advance and GPS signals received from GPS (Global Positioning System) satellites as needed. Information can be obtained.
[0035]
In subsequent S108, based on the results of S102 and S106, a retreat area candidate suitable as an area for stopping the vehicle is selected within the controllable range L1 to L2. In this embodiment, a technique is employed in which a plurality of evacuation area candidates are always listed as areas in which the vehicle is stopped within the controllable range L1 to L2.
As an example, FIG. 5A shows a case where three evacuation area candidates S1, S2, and S3 are specified. The evacuation area candidates located in the roadside band S0 are S1, and the current driving lane The evacuation area candidate located in front is indicated as S2, and the evacuation area candidate on the overtaking lane side is indicated as S3.
[0036]
In subsequent S110, an image analysis result of the CCD camera 314 mounted on the vehicle is subjected to image analysis, and vehicle peripheral information S4 such as the presence of a vehicle and other obstacles existing in the front, rear, and side of the vehicle is acquired. It is also possible to obtain the peripheral information S4 using road-to-vehicle communication, vehicle-to-vehicle communication, or the like.
[0037]
In subsequent S112, based on the evacuation area candidates S1 to S3 acquired in S108 and the peripheral information S4 acquired in S110, the evacuation area X that is an area in which the traveling vehicle should be stopped is determined. If there is no obstacle or the like in the vicinity as the peripheral information S4 obtained from the imaging result of the CCD camera 314, for example, since the area does not interfere with the following vehicle, the save area candidate S1 is determined as the save area X. Is done. Note that which of the save area candidates S1, S2, and S3 is to be preferentially determined as the save area depends on the design concept and is not particularly limited.
[0038]
In the subsequent S114, after reading the steering system failure determination result obtained from the failure determination unit 320, the process proceeds to S116, where it is determined whether a failure has occurred in the steering system, and the steering system is operating normally. In S116, “No” is determined, and the process returns to S102 described above, and the same processing is performed. Therefore, while the vehicle is running (after the ignition switch is turned on), a process for continuously determining the retreat area X is performed.
[0039]
If a failure actually occurs in the steering system, “Yes” is determined in S116, the process proceeds to S118, and the current position N of the vehicle read in S106 and the retreat area X of the vehicle determined in S112. Based on the position deviation and various vehicle state quantities, the magnitude of the braking force (target hydraulic pressure in the wheel cylinder 21) generated by the brake device of each wheel W is set. As described in S104, in order to stop the running vehicle in the retreat area X, how to distribute the braking force of each wheel depends on the positional deviation between the current position N and the retreat area X, It can be obtained by calculation or experimentally based on various vehicle state quantities. Therefore, for example, the relationship between the position deviation and the braking force of each wheel corresponding to the vehicle state quantity is mapped in advance, and in S118, a map search is performed based on the position deviation and the vehicle state quantity, You may set the braking force generated with a brake device.
[0040]
Then, the process proceeds to S120, and an operation control signal corresponding to the brake force set in S118 is output to the corresponding brake actuator 200 of each wheel. As a result, a predetermined braking force is applied to each wheel, and in this example, the vehicle changes its course in the left direction while decelerating.
[0041]
In the subsequent S122, it is determined whether the vehicle speed V has become V = 0, that is, whether the vehicle has stopped. If “No”, the process returns to S102 and the processes from S102 onward are continued.
[0042]
In this way, the retreat control process for stopping the vehicle A in the retreat area X is continuously executed. During this time, the vehicle A retreats while traveling on the track indicated by the two-dot chain line in FIG. Proceed toward region X. Then, when “Yes” in S122, that is, when the vehicle speed V = 0, the vehicle A is stopped in the retreat area X as shown in FIG.
[0043]
Although not shown in the flowchart of FIG. 4, if it is determined in S116 that a failure has occurred in the steering system, for example, a hazard lamp is automatically blinked, or the vehicle changes its course in the evacuation control. Accordingly, it is desirable to perform processing such as blinking the direction indicator.
[0044]
In addition, the selection of the evacuation area candidate as described above employs various methods such as selecting within the area excluding the oncoming lane, the intersection, and the level crossing from the geographical information around the traveling vehicle. Is possible. For example, an area excluding each area such as an oncoming lane side, an intersection, and a railroad crossing may be registered in advance on the map data of the navigation system 313 as an evacuation area candidate. When identifying evacuation area candidates, information such as road shapes such as intersections and railroad crossings, positions of obstacles including pedestrians, and following vehicles are used for road-to-vehicle communication and vehicle-to-vehicle communication. Can also be obtained.
[0045]
Here, FIGS. 6A to 6C illustrate a case where the evacuation area X changes according to a change in the surrounding situation after the evacuation control is started.
[0046]
As shown in FIG. 6A, it is assumed that a failure occurs in the steering system while the vehicle A travels in the overtaking lane. Also in the situation of FIG. 6A, as in the case of FIG. 5A, evacuation area candidates S1 to S3 are selected for the roadside band S0, the left lane, and the overtaking lane, respectively (S108). However, when the situation in which the following vehicle B exists in the left lane is acquired as the peripheral information S4 from the imaging result of the CCD camera 314 mounted on the vehicle (S110), it is desirable to maintain the traveling lane of the vehicle A as it is. Judgment is made and the evacuation area candidate S3 ahead of the vehicle A is selected as the evacuation area X (S112).
[0047]
When the retreat control is started, the vehicle A is gradually and gradually decelerated while maintaining a straight traveling state so as to stop in the front retreat area X. FIG. 6B shows a situation in which the vehicle is automatically decelerated in this way, and as a result, the succeeding vehicle B traveling in the left lane overtakes the vehicle A. As described above, when the situation around the vehicle A changes, there is no following vehicle, no obstacles, and the retreat area candidate S1 of the roadside zone S0 is included in the controllable range L1 to L2 (FIG. 6). In some cases, the save area candidate S1 is newly set as the save area X (see (b)). Subsequent evacuation control is performed with the newly set evacuation area X as the stop target position, and the evacuation control is executed so that the vehicle A finally stops in the evacuation area X of the roadside band S0. (FIG. 6C).
[0048]
FIG. 7 shows an example of selection of save area candidates S1, S2, and S3 near the intersection. The situation shown in FIG. 7 is a situation immediately before the vehicle A reaches the intersection, and the inside of the intersection and the level crossing located ahead are excluded from the save area candidates in advance on the map data. As the evacuation area candidates, the evacuation area candidate S1 in front of the vehicle A, the evacuation area candidate S2 that is an area where the intersection is turned to the left, and the evacuation area candidate S3 that is an area beyond the intersection are listed as the evacuation area candidates. Further, after obtaining peripheral information S4 from the imaging result of the CCD camera 314 and the like and confirming the presence of a right turn vehicle, a pedestrian, etc., the retreat area X is finally determined from the retreat area candidates S1 to S3.
[0049]
Next, a second embodiment will be described.
[0050]
In the above-described embodiment, the evacuation control for automatically stopping the vehicle in a predetermined evacuation area when a failure occurs in the steering system has been described. On the other hand, as described above, even when the steering system fails and steering becomes impossible, the course change direction desired by the driver is detected and the course of the vehicle is changed in that direction. However, the retraction control can be performed to stop the vehicle.
[0051]
As shown in FIG. 1, in a steering system in which a steering shaft 12 connected to a steering handle 10 and a rack shaft 14 connected to left and right wheels W are mechanically connected, gear engagement and a drive motor When the transmission ratio variable mechanism 16 fails due to seizure of the gear, when the assist device 15 of the power steering mechanism fails and the movement of the rack shaft 14 is restrained, or the gear is caught in the gear device 13. When this occurs, there may be a situation in which the steering wheel 10 cannot be rotated and the wheel W cannot be steered and is fixed at a certain steered angle.
[0052]
In this way, even when the rotation of the steering shaft 12 is restricted, that is, in a so-called locked state, if the driver operates the steering handle 10 along the direction in which the vehicle's course is desired to be changed, Since the steering shaft 12 is twisted according to the steering torque applied, the twisted amount can be detected by the torque sensor 311. Since the torque sensor 311 can detect the magnitude and direction of the steering torque applied to the steering handle 10, the detection result of the torque sensor 311 can be used to determine how much the driver is in either the left or right direction. You can generally grasp whether you want to change your course.
[0053]
Thus, an embodiment in which the retraction control is performed based on the detection result of the torque sensor 311 will be described with reference to the flowchart of FIG. FIG. 8 schematically illustrates a setting example of the braking force applied to the left and right front wheels, and the flowchart of FIG. 8 determines that a failure has occurred in the steering system in the failure determination unit 320 (see FIG. 3). It starts when it is done.
[0054]
First, in S202, the detection results of the torque sensor 311 and the wheel speed sensor 312 are read. In the subsequent S204, the basic target hydraulic pressure Po corresponding to the read vehicle speed V is set. In the subsequent S206, for example, the graph shown in FIG. And a correction amount α (α> 0) of the target hydraulic pressure corresponding to the detected magnitude of the steering torque T is set.
[0055]
Then, the process proceeds to S208, where it is determined whether the steering direction is the right steering based on the detection result of the torque sensor 311. If “Yes”, the process proceeds to S210, where the target hydraulic pressure P of the wheel cylinder 21 on the right wheel side is set. P = Po + α is set, and the target hydraulic pressure P of the wheel cylinder 21 on the left wheel side is set to P = Po−α. Thus, when the driver operates the steering handle 10 in the right direction, the target hydraulic pressure P is set so that the braking force applied to the right front wheel is relatively greater than that of the left front wheel.
[0056]
If “No” in S208, that is, if left steering, the process proceeds to S212, the target hydraulic pressure P of the wheel cylinder 21 on the right wheel side is set to P = Po−α, and the target of the wheel cylinder 21 on the left wheel side is set. The hydraulic pressure P is set to P = Po + α. Thus, when the driver operates the steering handle 10 in the left direction, the target hydraulic pressure P is set so that the braking force applied to the left front wheel is relatively greater than that of the right front wheel.
[0057]
After setting the target hydraulic pressure P in S210 or S212 as described above, the process proceeds to S214, and an operation control signal corresponding to the set target hydraulic pressure P is output to the brake actuator 200 of each wheel. As a result, a predetermined braking force is applied to each wheel, and the retraction control is executed such that the vehicle is automatically decelerated and the course of the vehicle is changed according to the steering direction.
[0058]
In the subsequent S216, it is determined whether the vehicle speed V has become V = 0, that is, whether the vehicle has stopped. If “No”, the process returns to S202 again and the processes from S202 onward are continued. Then, when “Yes” in S216, that is, when the vehicle stops, the evacuation control ends.
[0059]
In S210 and S212, the case where both the braking forces for the left and right wheels are changed by the correction amount α according to the steering direction is illustrated, but the present invention is not limited to this example, and different corrections are made for the left and right wheels. It is sufficient that the braking force can be adjusted so that the braking force on the steering direction side becomes relatively large, for example, the amount is set.
[0060]
Further, although the case where the brake force is controlled by the brake actuator 200 has been described, it is also possible to use the hydraulic pressure of the master cylinder 30 that generates the hydraulic pressure in conjunction with the driver's brake operation. In this case, as schematically shown in FIG. 10, for example, a hydraulic pressure control valve 260 is used to distribute the hydraulic pressure of the master cylinder 30 to the wheel cylinder 21 for the right front wheel and the wheel cylinder 21 for the left front wheel. Can be adopted. In this configuration, the hydraulic pressure generated according to the pedaling force applied by the driver to the brake pedal is supplied from the master cylinder 30 to the hydraulic pressure control valve 260 and is distributed to the left and right wheel cylinders 21 by the hydraulic pressure control valve 260.
[0061]
The hydraulic pressure control valve 260 is a mechanism capable of adjusting the distribution ratio of hydraulic pressure in accordance with a given control signal, and according to the steering direction and the magnitude of the steering torque detected by the torque sensor 311. By generating this control signal and applying it to the hydraulic pressure control valve 260, the left and right brake force distribution can be adjusted according to the steering direction and the magnitude of the steering torque.
[0062]
Therefore, even when the retraction control device is configured as described above, if a failure occurs in the steering system, the vehicle is applied in accordance with the steering direction while applying the braking force according to the pedal operation of the brake pedal 20 to the wheels. It is possible to carry out evacuation control that changes the course.
[0063]
In each of the embodiments described above, the steering system linked to the steering handle 10 and the steering system linked to the steering operation of the wheel W are described as an example of a mechanically connected steering system. However, it can also be applied to a steering system of the type schematically shown in FIG. This steering system has a structure in which a steering shaft 510 that is interlocked with the steering handle 500 and a steering shaft 520 that is interlocked with the steering operation of the wheel W are mechanically separated. A so-called steer-by-wire system is configured in which the operation of the steering actuator 530 is controlled in accordance with the operation state of 500, and the wheels W are steered in accordance with the operation of the steering handle 500. .
[0064]
In such a type of steering system, even when the steering operation of the wheel W is constrained due to, for example, a failure of the steering actuator 530, there may be a situation where the steering handle 500 can be rotated. In such a case, the driver's steering intention can be detected by detecting the operation state of the steering handle 500 with the steering angle sensor. Therefore, the same retraction control can be performed by executing the same control process based on the steering angle instead of the steering torque T described in the second embodiment.
[0065]
【The invention's effect】
As described above, according to the retraction control device according to each claim, the retraction control means for controlling the operation of the braking control mechanism and stopping the vehicle in a predetermined retraction area when a failure occurs in the steering system. A configuration comprising This makes it possible to control the traveling direction of the vehicle to some extent even when a failure occurs in the steering system that interferes with the steering control of the vehicle, and stops the vehicle at a more suitable position. Is possible.
[Brief description of the drawings]
FIG. 1 is a configuration diagram schematically showing a configuration of a steering system.
FIG. 2 is a hydraulic circuit diagram representatively showing a brake actuator related to one wheel.
FIG. 3 is an overall control system diagram including an evacuation control device.
FIG. 4 is a flowchart showing a save control process according to the first embodiment.
FIG. 5A is an explanatory diagram illustrating an example of setting of evacuation area candidates S1, S2, and S3, and FIG. 5B is a evacuation control process in which vehicle A travels on a two-dot chain line and stops in the evacuation area X. It is explanatory drawing which shows the condition which carried out.
FIGS. 6A, 6B, and 6C are explanatory diagrams sequentially showing the transition of the vehicle A and the subsequent vehicle B in order when the retreat control is performed.
FIG. 7 is an explanatory diagram illustrating an example of selection of save area candidates S1, S2, and S3 in the vicinity of an intersection.
FIG. 8 is a flowchart showing an evacuation control process according to the second embodiment.
FIG. 9 is a graph defining the relationship between the steering torque T (absolute value) and the correction amount α.
FIG. 10 is a hydraulic circuit diagram schematically showing a configuration example of a hydraulic pressure supply system.
FIG. 11 is a configuration diagram schematically showing another steering system.
[Explanation of symbols]
10,500 ... steering handle, 21 ... wheel cylinder,
30 ... Master cylinder, 100 ... Evacuation control device,
200: Brake actuator (braking control mechanism),
260 ... hydraulic pressure control valve (braking control mechanism),
313 ... Navigation system (peripheral information acquisition means),
314: CCD camera (peripheral information acquisition means),
510 ... steering shaft, 520 ... steering shaft, 530 ... steering actuator,
S1, S2, S3 ... save area candidates, X ... save area.

Claims (1)

An automatic vehicle evacuation device for stopping a vehicle in a predetermined evacuation area,
A braking control mechanism capable of controlling the magnitude of the braking force applied to a predetermined wheel;
A retraction control means for controlling the operation of the braking control mechanism and stopping the vehicle in a predetermined retreat area when a failure occurs in a steering system that steers wheels in conjunction with a steering wheel operation ;
The automatic retraction device for a vehicle, wherein the retraction control means controls the operation of the braking control mechanism according to a steering operation state of a driver .

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