Vehicle control system

Abstract

To provide a vehicle control system which can secure a distance from a vehicle to an obstacle of a vehicle periphery or a road end after the lapse of a prescribed standby time after detecting abnormality of a driver.SOLUTION: A vehicle control system (100) comprises: an EPS (33) which applies steering force to a steering device (5) of a vehicle (1); a steering angle sensor (27); and an ECU (10) which controls, when detecting abnormality of a driver and then the abnormality of the driver continues for a prescribed time, the vehicle to stop the vehicle. The ECU calculates, when the abnormality of the driver is detected, a self-aligning angular rate (ωsa) where the steering angle is decreased by self-aligning torque generated in the steering wheels of the vehicle, and the EPS executes steering angle reduction control that applies the steering force to the steering device until a prescribed time elapses after detecting the abnormality of the driver so that the steering angle is reduced at an angular rate smaller than the self-aligning angular rate.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a vehicle control system.

Background Art

[0002] In recent years, development of a driver abnormality response system that detects an abnormality when a driver falls into a state where they cannot drive safely and automatically stops the vehicle has been underway. For example, when detecting a driver's abnormality by detecting a breakdown in the driver's posture, it is assumed that the vehicle is gradually decelerated while maintaining the lane, and if possible, the vehicle is brought closer to the road shoulder or the like and automatically stopped (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the driver abnormality response system as described above, in consideration of the possibility that the detection of the driver's abnormal state is a false detection, the stop control is started after a predetermined waiting time (for example, 3.2 seconds) has elapsed since the abnormality detection. If the driver's abnormal state is no longer detected during the waiting time, or if the driver himself / herself presses the cancel switch for abnormality detection, the execution of the deceleration control is canceled.

[0005] When an abnormality actually occurs in the driver and the driving operation is impossible, it is desirable to perform steering intervention such as lane keeping control so that the vehicle stays near the center of the driving lane during the waiting time. However, there are cases where it is difficult to perform normal lane keeping control, such as when the vehicle is driving on a road without lane boundary lines such as white lines. Even in such cases, in order to ensure as much distance as possible to the road edge or obstacles when the waiting time has elapsed and the stop control is started, it is desirable to perform some steering intervention.

[0006] The present invention has been made to solve such problems, and an object thereof is to provide a vehicle control system capable of ensuring the distance to obstacles and road edges around the vehicle when a predetermined waiting time has elapsed since the detection of the driver's abnormality.

Means for Solving the Problems

[0007] In order to solve the above-described problems, the present invention is a vehicle control system including a driver abnormality detection device that detects an abnormality of a driver of a vehicle, a power steering device that applies a steering force to a steering device of the vehicle, a steering angle sensor that acquires a steering angle of the steering device, and a controller configured to control the vehicle to stop the vehicle when the abnormality of the driver continues for a predetermined time after the abnormality of the driver is detected by the driver abnormality detection device. The controller calculates a self-aligning angular velocity when the steering angle decreases due to the self-aligning torque generated on the steered wheels of the vehicle when the abnormality of the driver is detected by the driver abnormality detection device, and performs steering angle reduction control to apply a steering force to the steering device by the power steering device so that the steering angle decreases at an angular velocity smaller than the self-aligning angular velocity until a predetermined time elapses since the detection of the driver's abnormality.

[0008] According to the present invention configured as described above, when an abnormality of the driver is detected by the driver abnormality detection device, the controller calculates the self-aligning angular velocity when the steering angle decreases due to the self-aligning torque generated on the steered wheels of the vehicle, and until a predetermined time has elapsed since the detection of the driver's abnormality, the controller executes steering angle reduction control to cause the power steering device to apply a steering force to the steering device so that the steering angle decreases at an angular velocity smaller than the self-aligning angular velocity. Therefore, when an abnormality of the driver is detected during a turning operation of the vehicle, it is possible to suppress a decrease in the steering angle due to the self-aligning torque. As a result, it is possible to ensure a distance from the vehicle to the road edge or an obstacle when a predetermined waiting time has elapsed after the detection of the driver's abnormality.

[0009] In the present invention, preferably, when an abnormality of the driver is detected by the driver abnormality detection device, the controller is configured to execute the steering angle reduction control when the steering angle has increased or has been constant immediately before the detection of the driver's abnormality.

[0010] According to the present invention configured as described above, when an abnormality of the driver is detected, the controller executes the steering angle reduction control when the steering angle has increased or has been constant immediately before the detection of the driver's abnormality. Therefore, it is considered that the turning state of the vehicle continues even after the detection of the abnormality, and when it is desirable to perform steering intervention, it is possible to suppress a decrease in the steering angle due to the self-aligning torque. As a result, it is possible to reliably ensure a distance from the vehicle to the road edge or an obstacle when a predetermined waiting time has elapsed after the detection of the driver's abnormality.

[0011] In the present invention, preferably, when an abnormality of the driver is detected by the driver abnormality detection device, the controller is configured to execute the steering angle reduction control when the steering angle has decreased at an angular velocity smaller than the self-aligning angular velocity immediately before the detection of the driver's abnormality.

[0012] According to the present invention configured as described above, when an abnormality of the driver is detected, the controller executes steering angle reduction control when the steering angle has been decreasing at an angular velocity smaller than the self-aligning angular velocity immediately before the detection of the driver's abnormality. Therefore, it is considered that the turning state of the vehicle continues even after the abnormality is detected, and when it is desirable to perform steering intervention, it is possible to suppress the decrease in the steering angle due to the self-aligning torque. As a result, after the detection of the driver's abnormality, it is possible to surely secure the distance from the vehicle to the road edge or an obstacle when a predetermined waiting time has elapsed.

[0013] In the present invention, preferably, the vehicle control system includes a travelable area detection device that detects a travelable area in the traveling direction of the vehicle. When executing the steering angle reduction control, the controller detects the travelable area at the time of detecting the driver's abnormality, predicts the predicted travel route of the vehicle when reducing the steering angle at an angular velocity smaller than the self-aligning angular velocity for a plurality of angular velocities, and executes the steering angle reduction control so that the steering angle decreases at the angular velocity when the route length of the predicted travel route within the travelable area becomes the longest.

[0014] According to the present invention configured as described above, when executing the steering angle reduction control, the controller executes the steering angle reduction control so that the steering angle decreases at the angular velocity when the route length of the predicted travel route within the travelable area is the longest among the predicted travel routes of the vehicle when reducing the steering angle at an angular velocity smaller than the self-aligning angular velocity. Therefore, after the detection of the driver's abnormality, it is possible to widely secure the travelable area in the traveling direction of the vehicle when a predetermined waiting time has elapsed, and it is possible to secure the distance to the road edge or an obstacle as large as possible.

Advantages of the Invention

[0015] According to the vehicle control system of the present invention, it is possible to secure the distance to an obstacle or the road edge around the vehicle when a predetermined waiting time has elapsed since the detection of the driver's abnormality.

Brief Description of the Drawings

[0016] Figure 1 It is an explanatory diagram of a vehicle equipped with a vehicle control system according to an embodiment of the present invention. Figure 2 It is a block diagram showing a schematic configuration of a vehicle control system according to an embodiment of the present invention. Figure 3 It is a flowchart of vehicle control processing according to an embodiment of the present invention. Figure 4 It is a diagram showing a change in the steering angle in the steering angle reduction control according to an embodiment of the present invention. Figure 5 It is a diagram showing an example of a travel route when executing the steering angle reduction control according to an embodiment of the present invention. [Embodiments for Carrying Out the Invention]

[0017] Hereinafter, a vehicle control system according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0018] [System Configuration] First, with reference to FIGS. 1 and 2, the configuration of the vehicle control system according to the present embodiment will be described. FIG. 1 is an explanatory diagram of a vehicle equipped with the vehicle control system, and FIG. 2 is a block diagram of the vehicle control system.

[0019] The vehicle 1 according to the present embodiment includes a driving force source 2 such as an engine or an electric motor that outputs a driving force, a transmission 3 that transmits the driving force output from the driving force source 2 to the driving wheels, a brake 4 that applies a braking force to the vehicle 1, and a steering device 5 for steering the vehicle 1.

[0020] The vehicle control system 100 is configured to be able to control the acceleration, deceleration, and steering of the vehicle 1 (vehicle control). As shown in FIG. 2, the vehicle control system 100 includes an ECU (Electronic Control Unit) 10 as a controller, a plurality of sensors, and a plurality of control systems.

[0021] Specifically, the plurality of sensors include an in-vehicle camera 21, an out-vehicle camera 22, a vehicle speed sensor 23, an acceleration sensor 24, a yaw rate sensor 25, a steering grip sensor 26, a steering angle sensor 27, an accelerator sensor 28, and a brake sensor 29 for detecting the behavior of the vehicle 1 and the driving operations by the occupant. Further, the plurality of sensors include a positioning and navigation system 30 for detecting the position of the vehicle 1. The plurality of control systems include a power train control module (PCM) 31 for controlling the drive power source 2 and the transmission 3, a dynamic stability control system (DSC) 32 for controlling the drive power source 2 and the brake 4, and an electric power steering system (EPS) 33 for controlling the steering device 5.

[0022] Also, as other sensors, a peripheral sonar for measuring the distance and position of peripheral structures with respect to the vehicle 1, a radar for detecting obstacles around the vehicle 1, and the like may be included.

[0023] The ECU 10 executes various calculations based on the signals received from the plurality of sensors, and transmits control signals for appropriately operating the drive power source 2, the transmission 3, the brake 4, and the steering device 5 to the PCM 31, the DSC 32, and the EPS 33. The ECU 10 is composed of a computer including one or more processors (typically a CPU), a memory (such as a ROM and a RAM) for storing various programs, an input / output device, and the like. Note that the ECU 10 corresponds to an example of the "controller" in the present invention. Further, the ECU 10, together with the in-vehicle camera 21, the steering grip sensor 26, the accelerator sensor 28, and the brake sensor 29, constitutes an example of the "driver abnormality detection device" in the present invention. Furthermore, the ECU 10, together with the out-vehicle camera 22, constitutes an example of the "travelable region detection device" in the present invention.

[0024] The in-vehicle camera 21 photographs the driver and outputs image data. The ECU 10 detects the posture of the driver based on the image data received from the in-vehicle camera 21.

[0025] The external camera 22 captures the surroundings of the vehicle 1 and outputs image data. The ECU 10 identifies an object (e.g., a preceding vehicle, a parked vehicle, a pedestrian, a driving lane, a lane dividing line (lane boundary line, white line, yellow line), a traffic signal, a traffic sign, a stop line, an intersection, an obstacle, etc.), the state of the road surface, etc. based on the image data received from the external camera 22. Further, the ECU 10 detects a free space (a drivable area) around the vehicle 1 based on the image data received from the external camera 22. The drivable area includes not only the driving lane defined based on the detected lane dividing line or the like, but also a physically drivable area defined by the boundary between a paved surface and an unpaved surface, the boundary between a gutter and a road, etc., and is an area where there are no obstacles such as other vehicles and pedestrians. A known method can be used for detecting the free space based on the image data.

[0026] The vehicle speed sensor 23 detects the speed of the vehicle 1 based on, for example, the rotational speed of a wheel or a drive shaft. The acceleration sensor 24 detects the acceleration of the vehicle 1. This acceleration includes the acceleration in the longitudinal direction of the vehicle 1 and the acceleration in the lateral direction (i.e., lateral acceleration). Note that in this specification, the acceleration includes not only the rate of change of speed in the direction in which the speed increases, but also the rate of change of speed in the direction in which the speed decreases (i.e., deceleration). The yaw rate sensor 25 detects the yaw rate of the vehicle 1.

[0027] The steering grip sensor 26 detects whether the steering wheel is being gripped. The steering angle sensor 27 detects the rotation angle (steering angle) of the steering wheel of the vehicle 1. The accelerator sensor 28 detects the amount of depression of the accelerator pedal. The brake sensor 29 detects the amount of depression of the brake pedal.

[0028] The positioning and navigation system 30 includes a positioning system that detects the position of the vehicle 1 (current vehicle position information) using a GPS system and / or a gyro system, and a navigation system that stores map information internally. The ECU 10 identifies roads, intersections, traffic signals, buildings, etc. existing around the vehicle 1 (particularly in the traveling direction) based on the map information and the current vehicle position information. The map information may be stored in the ECU 10.

[0029] The PCM 31 controls the drive power source 2 of the vehicle 1 to adjust the driving force of the vehicle 1. For example, the PCM 31 controls the ignition plug, fuel injection valve, throttle valve, variable valve mechanism of the engine, the transmission 3, and the inverter that supplies power to the electric motor. When it is necessary to accelerate or decelerate the vehicle 1, the ECU 10 transmits a control signal to the PCM 31 to adjust the driving force.

[0030] The DSC 32 controls the drive power source 2 and the brake 4 of the vehicle 1 to perform deceleration control and attitude control of the vehicle 1. For example, the DSC 32 controls the hydraulic pump and valve unit of the brake 4 and controls the drive power source 2 via the PCM 31. When it is necessary to perform deceleration control or attitude control of the vehicle 1, the ECU 10 transmits a control signal to the DSC 32 to adjust the driving force or generate the braking force.

[0031] The EPS 33 controls the steering device 5 of the vehicle 1. For example, the EPS 33 controls an electric motor that applies torque (steering force) to the steering shaft of the steering device 5. The ECU 10 transmits a control signal to the EPS 33 to apply a steering force to the steering device 5.

[0032] [Vehicle Control Process] Next, with reference to FIGS. 3 to 5, the flow of the vehicle control process of the present embodiment will be described. FIG. 3 is a flowchart of the vehicle control process, FIG. 4 is a diagram showing changes in the steering angle by the steering angle reduction control in the vehicle control process, and FIG. 5 is a diagram showing an example of a traveling route when the steering angle reduction control is executed.

[0033] The vehicle control process in FIG. 3 is a process of causing vehicle 1 to make an emergency stop when an abnormal state of the driver is detected, and is repeatedly executed by ECU 10 at a predetermined cycle (for example, every 0.05 to 0.2 seconds) after the power of vehicle 1 is turned on.

[0034] When the vehicle control process is started, ECU 10 acquires the signals output from each of sensors 21 to 30 (step S1). The acquisition of the signals from each of sensors 21 to 30 is constantly executed in the background also in the processes after step S1.

[0035] Next, ECU 10 determines whether an abnormal state of the driver has been detected based on the signals acquired from in-vehicle camera 21, steering grip sensor 26, accelerator sensor 28, and brake sensor 29 (step S2). For example, based on the signal acquired from in-vehicle camera 21, ECU 10 determines whether the posture of the driver has collapsed (for example, when the entire upper body of the driver has fallen forward and the face has come close to the vicinity of the steering wheel, or when the head or upper body of the driver remains tilted to one side). Also, based on the signal acquired from steering grip sensor 26, ECU 10 determines whether the driver is gripping the steering wheel. Further, based on the signals acquired from accelerator sensor 28 and brake sensor 29, ECU 10 determines whether an operation of the accelerator pedal or the brake pedal is being performed. Then, when the three conditions that the posture of the driver has collapsed, the steering wheel is not being gripped, and neither the accelerator pedal nor the brake pedal is being operated are satisfied, it is determined that an abnormal state of the driver has been detected. On the other hand, when even one of the above three conditions is not satisfied, ECU 10 does not determine that an abnormal state of the driver has been detected.

[0036] As a result of the determination in step S2, when an abnormal state of the driver is not detected (step S2: NO), since there is no need to cause vehicle 1 to make an emergency stop, ECU 10 ends the vehicle control process.

[0037] On the other hand, when an abnormal state of the driver is detected (step S2: YES), the ECU 10 calculates the self-aligning torque generated on the steered wheels (front wheels of the vehicle 1 in this embodiment) of the vehicle 1 based on the signals acquired from the vehicle speed sensor 23, the acceleration sensor 24, and the yaw rate sensor 25 (step S3). The self-aligning torque refers to the moment (torque) generated in the direction of returning the slip angle of the tire to 0 when the tire has a slip angle and generates a lateral force (i.e., when the tire is skidding). When the vehicle 1 is traveling on a curve, due to the generation of this self-aligning torque, a torque in the direction of decreasing the steering angle of the vehicle 1 is applied from the road surface to the steering device 5 via the tires. The ECU 10 refers to, for example, a map (pre-calculated and stored in the memory) that specifies the relationship between the vehicle speed, the steering angle, the yaw rate, and the self-aligning torque generated on the front wheels, and acquires the self-aligning torque corresponding to the vehicle speed based on the signal acquired from the vehicle speed sensor 23, the steering angle based on the signal acquired from the steering angle sensor 27, and the yaw rate acquired from the yaw rate sensor 25.

[0038] Next, the ECU 10 calculates the angular velocity (hereinafter referred to as "self-aligning angular velocity") ωsa at which the steering angle decreases due to the self-aligning torque generated on the front wheels of the vehicle 1 when no steering force is applied to the steering device 5 from the driver and the EPS 33 (step S4). Here, the self-aligning torque decreases as the steering angle decreases and approaches 0, and the self-aligning angular velocity ωsa decreases as the self-aligning torque decreases. That is, the self-aligning angular velocity ωsa changes according to the steering angle. Therefore, the ECU 10 calculates the time change of the self-aligning angular velocity ωsa after detecting the abnormal state of the driver assuming a constant vehicle speed. For example, referring to a map (pre-calculated and stored in the memory) that specifies the relationship between the self-aligning torque and the steering angle at the time of detecting the abnormal state of the driver and the time change of the self-aligning angular velocity ωsa, the ECU 10 acquires the time change of the self-aligning angular velocity ωsa corresponding to the steering angle acquired in step S1 and the self-aligning torque calculated in step S3.

[0039] Next, based on the signal acquired from the steering angle sensor 27, the ECU 10 determines whether the steering angle was increasing or constant immediately before the detection of the driver's abnormal state (step S5). That is, it determines whether an operation of turning the steering wheel or holding it was being performed when the driver's state was normal.

[0040] As a result, if the steering angle was increasing or constant immediately before the detection of the driver's abnormal state (step S5: YES), it is considered that the turning state of the vehicle 1 continues even after the detection of the abnormal state. In this case, when the steering angle decreases due to the self-aligning torque, the vehicle 1 will approach the road edge on the outside of the curve. Therefore, it is desirable to suppress the decrease in the steering angle.

[0041] Therefore, first, the ECU 10 detects the free space in the traveling direction of the vehicle 1 based on the image data acquired from the outside camera 22 (step S6).

[0042] Next, the ECU 10 predicts the predicted traveling path of the vehicle 1 when the steering angle is decreased at an angular velocity smaller than the self-aligning angular velocity ωsa for a plurality of angular velocities, and sets the angular velocity at which the path length of the predicted traveling path in the free space becomes the longest as the angular velocity ω when performing the steering angle decrease control for decreasing the steering angle of the steering device 5 (step S7).

[0043] For example, the ECU 10 calculates the time change of the angular velocity obtained by multiplying the time change of the self-aligning angular velocity ωsa calculated in step S4 by a coefficient less than 1, using different coefficients. Then, the time change of the steering angle is calculated from the time change of the angular velocity in each case of the coefficient, and a predicted travel path is calculated based on the calculated time change of the steering angle and the vehicle speed. Since the angular velocity decreases as the coefficient decreases, the decrease in the steering angle becomes gradual, and the curve radius of the predicted travel path of the vehicle 1 decreases. The ECU 10 identifies the predicted travel path with the longest path length within the free space from among the plurality of acquired predicted travel paths, and sets the angular velocity used for calculating the predicted travel path as the angular velocity ω for executing the steering angle reduction control.

[0044] FIG. 4 is a diagram illustrating the time change of the steering angle when reducing the steering angle by the steering angle reduction control. The horizontal axis represents the elapsed time from the detection of the abnormal state of the driver, and the vertical axis represents the steering angle. In FIG. 4, the dotted line indicates the time change of the steering angle when reducing the steering angle with the self-aligning angular velocity ωsa, and the solid line indicates the time change of the steering angle when reducing the steering angle with an angular velocity smaller than the self-aligning angular velocity ωsa. As shown in FIG. 4, when reducing the steering angle with an angular velocity smaller than the self-aligning angular velocity ωsa, the decrease in the steering angle becomes gentler than when reducing the steering angle with the self-aligning angular velocity ωsa.

[0045] FIG. 5 is a diagram showing an example of a travel path when executing the steering angle reduction control. In FIG. 5, E represents the left and right road edges of the vehicle 1, and the dotted area FS represents the free space detected at the time of detecting the abnormal state of the driver. The dotted line indicates the predicted travel path B when reducing the steering angle with the self-aligning angular velocity ωsa, and the solid line is the predicted travel path A with the longest path length within the free space FS when reducing the steering angle with an angular velocity ω smaller than the self-aligning angular velocity ωsa. The dashed-dotted line is the predicted travel path when reducing the steering angle with an angular velocity ω even smaller than ω A and is the predicted travel path A with the longest path length within the free space FS when reducing the steering angle with an angular velocity ω smaller than the self-aligning angular velocity ωsa. The dash-dotted line is the angular velocity ω A even smaller than ω CIt shows the predicted travel route C when the steering angle is decreased. As shown in FIG. 5, the smaller the angular velocity when the steering angle is decreased, the smaller the curve radius of the predicted travel route of the vehicle 1, and the curve radius of the predicted travel route C is the smallest. In the example of FIG. 5, the angular velocity ω A used for calculating the predicted travel route A with the longest path length within the free space FS is set as the angular velocity ω for executing the steering angle decrease control.

[0046] Next, the ECU 10 starts the steering angle decrease control for applying a steering force to the steering device 5 by the EPS 33 so that the steering angle decreases at the angular velocity ω set in step S7 (step S8). In the example of FIG. 5, by executing the steering angle decrease control, the vehicle 1 comes to travel along the predicted travel route A. That is, compared with the case where the steering angle decreases due to the self-aligning torque without executing the steering angle decrease control, the curve radius of the travel route of the vehicle 1 becomes smaller.

[0047] Also, in step S5, when the steering angle has not increased and is not constant immediately before detecting the abnormal state of the driver (step S5: NO), that is, when the steering angle has been decreasing, the ECU 10 determines whether the angular velocity wn of the steering angle immediately before detecting the abnormal state of the driver is less than the self-aligning angular velocity ωsa (step S9).

[0048] As a result, when the angular velocity wn of the steering angle immediately before detecting the abnormal state of the driver is less than the self-aligning angular velocity ωsa (step S9: YES), that is, when the driver's state was normal and an operation of gradually turning back the steering wheel while resisting the self-aligning torque was being performed, it is considered that the turning state of the vehicle 1 continues. In this case, when the steering angle decreases due to the self-aligning torque, the vehicle 1 will approach the road edge E on the outside of the curve, so it is desirable to suppress the decrease in the steering angle. Therefore, the process proceeds to step S6, and the ECU 10 detects the free space FS. Then, the process of step S7 is executed, and the steering angle decrease control is started in step S8.

[0049] On the other hand, when the angular velocity wn of the steering angle immediately before detecting the abnormal state of the driver is not less than the self-aligning angular velocity ωsa (step S9: NO), that is, when the driver's state was normal and an operation to quickly turn back the steering wheel was being performed, it is considered that the vehicle 1 has already returned from the turning state to a state close to the straight-ahead state. That is, the necessity of suppressing the decrease in the steering angle is small. Therefore, the ECU 10 proceeds to step S10 without starting the steering angle decrease control.

[0050] After starting the steering angle decrease control in step S8, or after it is determined in step S9 that the angular velocity wn of the steering angle immediately before detecting the abnormal state of the driver is not less than the self-aligning angular velocity ωsa (step S9: NO), the ECU 10 determines whether the abnormal state of the driver continues, that is, whether the abnormal state of the driver is still detected (step S10).

[0051] As a result, when the abnormal state of the driver does not continue (step S10: NO), that is, when the abnormal state of the driver is not detected, it is considered that the driver is in a normal state and an emergency stop is unnecessary. Therefore, the ECU 10 ends the steering angle decrease control (step S11) and ends the vehicle control process.

[0052] On the other hand, when the abnormal state of the driver continues (step S10: YES), the ECU 10 determines whether a predetermined waiting time (3.2 seconds in this embodiment) has elapsed since detecting the abnormal state of the driver in step S2 (step S12). As a result, when the waiting time has not elapsed (step S12: NO), the process returns to step S10. Thereafter, the ECU 10 repeats the determinations in steps S10 and S12 until the abnormal state of the driver is no longer detected or the waiting time has elapsed. When the steering angle decrease control is started in step S8, the ECU 10 continues to execute the steering angle decrease control until the waiting time has elapsed.

[0053] When the waiting time has elapsed after detecting an abnormal state of the driver (step S12: YES), since it is considered that the detection of the abnormal state of the driver is not a false detection, the ECU 10 executes emergency stop control (step S13). For example, the ECU 10 causes the PCM 31 and the DSC 32 to control the drive power source 2 and the brake 4 so that a predetermined deceleration (for example, a deceleration of 0.2G or less) is generated until the vehicle speed becomes zero. After the vehicle 1 stops, the ECU 10 ends the vehicle control process.

[0054] In the example of FIG. 5, when the steering angle reduction control is started from the time t0 when an abnormal state of the driver is detected, and if the vehicle 1 travels along the predicted travel route A during the waiting time, at the time t1 when the waiting time has elapsed, a free space FS in front of the vehicle 1 is wider than other predicted travel routes B and C. That is, when the abnormal state of the driver is confirmed due to the elapse of the waiting time and the emergency stop control is started, the distance between the vehicle 1 and an obstacle or the road edge E in front can be ensured as large as possible.

[0055] [Operation and Effect] Next, the operation and effect of the vehicle control system 100 of the present embodiment described above will be described.

[0056] When an abnormal state of the driver is detected, the ECU 10 calculates a self-aligning angular velocity when the steering angle decreases due to the self-aligning torque generated on the steered wheels of the vehicle 1, and until a predetermined time has elapsed since the detection of the abnormal state of the driver, the EPS 33 is used to execute steering angle reduction control to apply a steering force to the steering device 5 so that the steering angle decreases at an angular velocity smaller than the self-aligning angular velocity. Therefore, when an abnormal state of the driver is detected during the turning travel of the vehicle 1, the decrease in the steering angle due to the self-aligning torque can be suppressed. As a result, the distance from the vehicle 1 to the road edge or an obstacle when a predetermined waiting time has elapsed after the detection of the abnormal state of the driver can be ensured.

[0057] Further, when an abnormal state of the driver is detected, the ECU 10 executes steering angle reduction control when the steering angle has been increasing or constant immediately before the detection of the abnormal state of the driver. Therefore, it is considered that the turning state of the vehicle 1 continues even after the detection of the abnormal state, and when it is desirable to perform steering intervention, it is possible to suppress the reduction of the steering angle due to the self-aligning torque. As a result, after the detection of the abnormal state of the driver, it is possible to surely secure the distance from the vehicle 1 to the road edge or an obstacle when a predetermined waiting time has elapsed.

[0058] Further, when an abnormal state of the driver is detected, the ECU 10 executes steering angle reduction control when the steering angle has been decreasing at an angular velocity smaller than the self-aligning angular velocity immediately before the detection of the abnormal state of the driver. Therefore, it is considered that the turning state of the vehicle 1 continues even after the detection of the abnormal state, and when it is desirable to perform steering intervention, it is possible to suppress the reduction of the steering angle due to the self-aligning torque. As a result, after the detection of the abnormal state of the driver, it is possible to surely secure the distance from the vehicle 1 to the road edge or an obstacle when a predetermined waiting time has elapsed.

[0059] Further, when executing the steering angle reduction control, the ECU 10 executes the steering angle reduction control so that the steering angle decreases at the angular velocity at which the path length of the predicted travel path within the travelable region is the longest among the predicted travel paths of the vehicle 1 when the steering angle is decreased at an angular velocity smaller than the self-aligning angular velocity. Therefore, after the detection of the abnormal state of the driver, when a predetermined waiting time has elapsed, it is possible to widely secure the travelable region in the traveling direction of the vehicle 1, and it is possible to secure the distance to the road edge and an obstacle as large as possible.

Explanation of Signs

[0060] 1 Vehicle 2 Driving force source 3 Transmission 4 Brake 5 Steering device 10 ECU 21 In-vehicle camera 22 Out-vehicle camera 23 Vehicle speed sensor 24 Acceleration sensor 25 Yaw rate sensor 26 Steering grip sensor 27 Steering angle sensor 28 Accelerator sensor 29 Brake sensor 30 Positioning and navigation system 31 PCM 32 DSC 33 EPS 100 Vehicle control system A, B, C Predicted driving routes E Road edge FS Free space

Claims

1. A driver abnormality detection device for detecting an abnormality of a driver of a vehicle, a power steering device for applying a steering force to a steering device of the vehicle, a steering angle sensor for acquiring a steering angle of the steering device, and a controller configured to control the vehicle to stop the vehicle when the abnormality of the driver continues for a predetermined time after the abnormality of the driver is detected by the driver abnormality detection device. The controller is when the abnormality of the driver is detected by the driver abnormality detection device, calculate a self-aligning angular velocity when the steering angle decreases due to a self-aligning torque generated on a steered wheel of the vehicle, and execute a steering angle decrease control for applying a steering force to the steering device by the power steering device so that the steering angle decreases at an angular velocity smaller than the self-aligning angular velocity until the predetermined time elapses since the detection of the driver abnormality. It is configured as a vehicle control system.

2. The controller is configured to execute the steering angle decrease control when the abnormality of the driver is detected by the driver abnormality detection device and the steering angle has increased or been constant immediately before the detection of the driver abnormality. The vehicle control system according to claim 1.

3. The controller is configured to execute the steering angle decrease control when the abnormality of the driver is detected by the driver abnormality detection device and the steering angle has decreased at an angular velocity smaller than the self-aligning angular velocity immediately before the detection of the driver abnormality. The vehicle control system according to claim 1 or 2.

4. It includes a travelable area detection device for detecting a travelable area in the traveling direction of the vehicle, The controller is when executing the steering angle decrease control, detect the travelable area at the time of detection of the driver abnormality, predict the predicted travel path of the vehicle when the steering angle is decreased at an angular velocity smaller than the self-aligning angular velocity for a plurality of the angular velocities, and execute the steering angle decrease control so that the steering angle decreases at the angular velocity when the path length of the predicted travel path within the travelable area becomes the longest. It is configured as the vehicle control system according to claim 1 or 2.

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