Vehicle Control Systems

Abstract

To provide a vehicle control system capable of improving vehicle safety.SOLUTION: A vehicle control system comprises: an on-vehicle sensor that outputs information about a target around the own vehicle and information about a traveling state of the own vehicle; a driving support ECU equipped with a risk reduction function including at least one of a lane departure prevention function that controls at least one of a warning device, a drive device, a braking device, and a steering device so as to prevent the own vehicle from deviating from the lane in which the own vehicle is traveling based on the information obtained from the on-vehicle sensor, and an emergency stop function that stops the own vehicle when a driver is experiencing an abnormality; and a switching device for switching between a state in which the risk reduction function is enabled and a state in which the risk reduction function is disabled. The driving support ECU forcibly enables the risk reduction function when the own vehicle collides with an object while the risk reduction function is disabled by the switching device.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a vehicle control system having a function of improving vehicle safety. [Background technology]

[0002] There is known a vehicle control system (hereinafter referred to as "conventional system") having a function (hereinafter referred to as "risk reduction function") for improving the safety of the vehicle (see, for example, Patent Document 1 below). The risk reduction function of this conventional system includes a function for playing a predetermined warning sound when the vehicle deviates from the center to an end (right or left end) in the width direction of the lane, and a function for controlling (automatic steering, automatic braking) the steering device, drive device, braking device, etc. so that the vehicle returns to the center in the width direction of the lane (hereinafter these functions are referred to as "lane departure suppression function"). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-252500 A Summary of the Invention

[0004] In some vehicle control systems equipped with the risk reduction function, the risk reduction function may be manually switched between an enabled state and a disabled state by the driver. In this case, when the risk reduction function is manually disabled, the playback of warning sounds, automatic steering, automatic braking, and the like are not performed even if the vehicle falls into a safety-unfavorable situation.

[0005] An object of the present invention is to provide a vehicle control system capable of improving the safety of a vehicle.

[0006] In order to solve the above problems, the vehicle control system (1) of the present invention comprises: An on-board sensor (20) that outputs information regarding targets around the vehicle and information regarding the running state of the vehicle; a control device (10) having a risk reduction function including at least one of a lane departure prevention function that controls at least one of a warning device (24), a drive device (30), a braking device (40) and a steering device (60) of the host vehicle so as to prevent the host vehicle from departing from the lane in which the host vehicle is traveling based on information acquired from the on-board sensor, and an emergency stop function that stops the host vehicle when an abnormality occurs in the driver; A switching device (2b) for switching between an enabled state and a disabled state of the risk reduction function; Equipped with. The control device includes: When the magnitude of the acceleration of the host vehicle is within a predetermined range that exceeds the range of acceleration that can occur during normal driving, it is determined that the host vehicle has lightly collided with an object; When the risk reduction function is disabled by the switching device, the host vehicle hits an object. Minor collision If it is determined that the risk reduction function has been enabled, the risk reduction function is forcibly enabled.

[0007] Here, the switching device is, for example, a switch device that can be manually operated by the driver (or passenger). The switching device also includes, for example, a device that automatically disables the lane departure prevention function when it detects that the driver has intentionally changed lanes, and a device that automatically enables the lane departure prevention function when it detects that the driver has an abnormality.

[0008] In a vehicle equipped with the above-mentioned vehicle control system, a switching device switches between an enabled state and a disabled state of the risk reduction function. When the risk reduction function is disabled, for example, if the vehicle deviates from the lane and collides with an object, the risk reduction function is forcibly enabled. As a result, for example, when the risk reduction function includes a lane departure suppression function, the control device assists the driver in driving the vehicle in a situation in which it is difficult for the driver to drive the vehicle. Also, for example, when the risk reduction function includes an emergency stop function, the control device stops the vehicle in a situation in which the driver is unable to drive the vehicle. Therefore, the vehicle control system according to the present invention can improve the safety of the vehicle compared to conventional systems.

[0009] In addition, in a vehicle control system according to an aspect of the present invention, The control device determines that the vehicle has made a minor collision with an object when the magnitude of the vehicle's acceleration (G) is within a predetermined range (GA) that exceeds the range of acceleration that can occur during normal driving, and when the integral value of the magnitude of the acceleration within a predetermined time from the point at which the magnitude of the vehicle's acceleration exceeds the lower limit of the predetermined range exceeds a threshold value.

[0010] This makes it possible to forcibly activate the risk reduction function in a situation where the host vehicle collides relatively lightly with an object (for example, a collision that does not cause the airbag device to deploy).

[0011] In addition, in a vehicle control system according to another aspect of the present invention, the switching device includes a first operator (2b1) for manually switching between an enabled state and a disabled state of the lane departure prevention function, and a second operator (2b2) ​​for manually switching between an enabled state and a disabled state of the emergency stop function, When the vehicle departs from its lane and collides with an object while at least one of the lane departure prevention function and the emergency stop function has been manually disabled, the control device forcibly enables the function that has been manually disabled.

[0012] This allows the driver to activate some of the risk reduction functions and disable other functions according to his / her preference.

[0013] In addition, in a vehicle control system according to another aspect of the present invention, The risk reduction function includes the emergency stop function, If the speed of the vehicle exceeds a threshold value between the time the risk reduction function is forcibly activated and the time braking of the vehicle is initiated by the emergency stop function, the control device controls the braking device so that the vehicle is stopped immediately, regardless of whether an abnormality is occurring with the driver.

[0014] According to this, for example, when the host vehicle collides with an object at a relatively high speed, the host vehicle can be stopped immediately. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a block diagram of a vehicle control system according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view showing a scene in which a vehicle is slightly offset to the left from the center in the width direction of the lane. [Diagram 3] FIG. 3 is a time chart showing the process of executing various controls when the host vehicle deviates from the lane and hits an object lightly. [Figure 4] FIG. 4 is a flowchart of the first program (lane departure prevention function). [Diagram 5] FIG. 5 is a flowchart of the second program (emergency stop function). [Figure 6] FIG. 6 is a flowchart of the third program (forced activation function). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] (Outline of configuration) As shown in FIG. 1, a vehicle control system 1 according to an embodiment of the present invention is mounted on a vehicle V (hereinafter, sometimes referred to as "host vehicle"). The vehicle control system 1 has a risk reduction function for improving the safety of the host vehicle, as will be described in detail later. The risk reduction function includes a lane departure suppression function similar to that of the conventional system described above, as well as an emergency stop function for immediately stopping the host vehicle when an abnormality occurs in the driver. The driver can manually switch between a state in which the risk reduction function is enabled and a state in which it is disabled. Furthermore, the vehicle control system 1 has a forced activation function forcibly enabling the risk reduction function when a predetermined condition is met.

[0017] (Specific configuration) As shown in FIG. 1, the vehicle control system 1 includes a driving assistance ECU 10, an in-vehicle sensor 20, a drive device 30, a braking device 40, a shift switching device 50, and a steering device 60.

[0018] The driving assistance ECU 10 includes a microcomputer equipped with a CPU 10a, a ROM 10b, a RAM 10c, and the like. In this specification, "ECU" means an electronic control unit, and includes a microcomputer equipped with a CPU, a ROM, a RAM, and the like. The CPU realizes various functions by executing instructions stored in the ROM. Furthermore, the driving assistance ECU 10 includes a communication device 10d that transmits and receives information to and from a server computer via a wireless communication line. In addition, the driving assistance ECU 10 includes a timer 10e that measures time.

[0019] The driving assistance ECU 10 is connected to other ECUs (an engine ECU 31, a brake ECU 41, a SBW·ECU 51, and an EPS·ECU 61, which will be described later) via a CAN (Controller Area Network) so as to be able to transmit and receive information to and from each other.

[0020] The on-board sensor 20 includes a sensor that acquires vehicle surrounding information including information about three-dimensional objects present around the vehicle V and information about road markings around the vehicle V. That is, for example, the on-board sensor 20 includes a sensor that acquires information about moving objects such as automobiles (other vehicles), pedestrians, and bicycles, as well as fixed objects such as white lines on the road, guardrails, and traffic lights.

[0021] Specifically, the on-board sensor 20 includes a radar sensor 21, an ultrasonic sensor 22, a camera 23, and a navigation system 24.

[0022] The radar sensor 21 includes a radar transmitting / receiving unit and a signal processing unit (not shown). The radar transmitting / receiving unit emits millimeter-wave band radio waves (hereinafter referred to as "millimeter waves") to the area around the vehicle, and receives millimeter waves reflected by a three-dimensional object present within the emission range (i.e., reflected waves). The signal processing unit calculates the distance between the vehicle V and the three-dimensional object, the relative speed between the vehicle V and the three-dimensional object, the relative position (direction) of the three-dimensional object with respect to the vehicle V, etc. based on the phase difference between the transmitted millimeter wave and the received reflected wave, the attenuation level of the reflected wave, the time from transmitting the millimeter wave to receiving the reflected wave, etc., and transmits the results to the driving assistance ECU 10.

[0023] The ultrasonic sensor 22 transmits ultrasonic waves in a pulsed manner to a predetermined range around the vehicle and receives the reflected waves reflected by a three-dimensional object. The ultrasonic sensor 22 calculates the "reflection point, which is the point on the three-dimensional object where the transmitted ultrasonic waves are reflected," the "distance between the ultrasonic sensor and the three-dimensional object," and the like based on the time from transmitting the ultrasonic waves to receiving the reflected waves, and transmits the results to the driving assistance ECU 10.

[0024] The camera 23 includes an imaging device and an image analysis device. The imaging device is, for example, a digital camera incorporating an imaging element such as a charge coupled device (CCD) or a CMOS image sensor (CIS). The imaging device is disposed on the upper part of the front windshield glass. The imaging device captures an image of the front view of the vehicle at a predetermined frame rate and outputs the image data obtained to the image analysis device. The image analysis device analyzes the acquired image data and obtains information about a target located in front of the vehicle V from the image. The image analysis device recognizes, for example, white lines on the road (such as lane lines and stop lines) and transmits the recognition result to the driving assistance ECU 10.

[0025] The navigation system 24 receives GPS signals from multiple artificial satellites, and detects the current location (latitude and longitude) of the vehicle V based on the received GPS signals. The navigation system 24 also stores map data representing a map. The navigation system 24 transmits vehicle position data representing the detected current location to the driving assistance ECU 10.

[0026] The on-vehicle sensor 20 further includes a sensor for acquiring information regarding the traveling state (speed, acceleration) of the vehicle V, and information regarding the operation mode of an operator provided on the vehicle V.

[0027] Specifically, the on-vehicle sensors 20 include a speed sensor 25, an acceleration sensor 26, an accelerator pedal sensor 27, a brake pedal sensor 28, a shift lever sensor 29, a steering sensor 2a, and a switch 2b.

[0028] The speed sensor 25 includes a wheel speed sensor that generates one pulse signal (wheel pulse signal) every time the wheels of the host vehicle rotate a predetermined angle. The speed sensor 25 measures the number of pulses per unit time of the wheel pulse signal transmitted from the wheel speed sensor, calculates the rotation speed (wheel speed) of each wheel based on the measured number of pulses, and calculates the speed vs (actual vehicle speed) of the host vehicle based on the wheel speed of each wheel. The speed sensor 25 transmits data representing the speed vs to the driving assistance ECU 10.

[0029] The acceleration sensor 26 detects the acceleration G of the vehicle V (for example, the acceleration in the vehicle width direction, the acceleration in the front-rear direction, etc.) of the vehicle V. The acceleration sensor 26 transmits data representing the acceleration G to the driving assistance ECU 10.

[0030] The accelerator pedal sensor 27 detects the depression depth AD of an accelerator pedal (not shown) of the vehicle V. The accelerator pedal sensor 27 transmits to the driving assistance ECU 10 data indicating the depression depth AD of the accelerator pedal.

[0031] The brake pedal sensor 28 detects the depression depth BD of a brake pedal (not shown) of the vehicle V. The brake pedal sensor 28 transmits data indicative of the depression depth BD to the driving assistance ECU 10.

[0032] The shift lever sensor 29 detects the position (shift lever position SP) of a shift lever (not shown) of the vehicle V. The shift lever sensor 29 transmits data indicating the shift lever position SP to the driving assistance ECU 10.

[0033] The steering sensor 2a detects a steering angle (also called a steering angle or a turning angle) θ of a steering wheel. The steering sensor 2a transmits data indicating the detected steering angle θ to the driving assistance ECU 10.

[0034] The switch 2b is an operator (e.g., a push button switch operator) that the driver operates when switching between an enabled state and a disabled state of the risk reduction function. When the driver operates the switch 2b (presses the button) during a period in which the risk reduction function is disabled, the switch 2b transmits an enable signal to the driving assistance ECU 10, indicating that "the driver is requesting to enable the risk reduction function." When the driving assistance ECU 10 receives the enable signal, it sets the flag F to "1." Furthermore, when the driver operates the switch 2b during a period in which the risk reduction function is enabled, the switch 2b transmits a disable signal to the driving assistance ECU 10, indicating that "the driver is requesting to disable the risk reduction function." When the driving assistance ECU 10 receives the disable signal, it sets the flag F to "0."

[0035] The drive device 30 generates a drive force and applies the drive force to drive wheels among the wheels (left front wheel, right front wheel, left rear wheel, and right rear wheel). The drive device 30 includes an engine ECU 31, an engine actuator 32, an internal combustion engine 33, a transmission 34, a drive force transmission mechanism (not shown) that transmits the drive force to the wheels, and the like. The engine ECU 31 is connected to the engine actuator 32. The engine actuator 32 includes a throttle valve actuator that changes the opening degree of the throttle valve of the internal combustion engine 33. The engine ECU 31 acquires the depression depth AD of the accelerator pedal from the driving assistance ECU 10. The driving assistance ECU 10 can appropriately correct the depression depth AD acquired from the accelerator pedal sensor 27 and transmit it to the engine ECU 31. The engine ECU 31 drives the engine actuator 32 according to the depression depth AD acquired from the driving assistance ECU 10. In this manner, the torque generated by the internal combustion engine 33 is controlled. The torque generated by the internal combustion engine 33 is transmitted to drive wheels via a transmission 34 and a driving force transmission mechanism (for example, a drive shaft).

[0036] When the vehicle V to which the vehicle control system 1 is applied is a hybrid vehicle (HEV), the engine ECU 31 can control the driving force of the vehicle generated by either one or both of an "internal combustion engine and an electric motor" as a vehicle driving source. When the vehicle V to which the vehicle control system 1 is applied is an electric vehicle (BEV), instead of the engine ECU 31, an electric motor ECU that controls the driving force of the vehicle generated by an "electric motor" as a vehicle driving source may be used.

[0037] The braking device 40 applies a braking force to the wheels. The braking device 40 includes a brake ECU 41, a hydraulic circuit 42, and a brake caliper 43. The hydraulic circuit 42 includes a reservoir, an oil pump, various valve devices, a hydraulic sensor, and the like, which are not shown. The brake caliper 43 is a hydraulic actuator having a cylinder and a piston. When oil is supplied to the cylinder, the piston is pushed out of the cylinder. A brake pad is provided at the tip of the piston, and this brake pad is pressed against a brake disc. The brake ECU 41 acquires the depression depth BD of the brake pedal from the driving assistance ECU 10. The driving assistance ECU 10 can appropriately correct the depression depth BD acquired from the brake pedal sensor 28 and transmit it to the brake ECU 41. The brake ECU 41 transmits a hydraulic control command to the hydraulic circuit 42 according to the depression depth BD acquired from the driving assistance ECU 10. The hydraulic circuit 42 adjusts the hydraulic pressure in the cylinder of the brake caliper 43 according to the hydraulic control command acquired from the brake ECU 41. In this manner, the braking force of the brake caliper 43 on the wheels (brake discs) is controlled.

[0038] The shift switching device 50 switches the shift position of the transmission 34. The shift switching device 50 includes an SBW (Shift-by-Wire) ECU 51, an SBW actuator 52, a shift switching mechanism 53, and the like. The SBW ECU 51 is connected to the SBW actuator 52. The SBW ECU 51 acquires a shift lever position SP from the driving assistance ECU 10. The driving assistance ECU 10 can appropriately correct the shift lever position SP acquired from the shift lever sensor 29 and transmit it to the SBW ECU 51. The SBW ECU 51 transmits a shift switching command to the SBW actuator 52 in accordance with the shift lever position SP acquired from the driving assistance ECU 10. The SBW actuator 52 controls the shift switching mechanism 53 in accordance with the shift switching command acquired from the SBW ECU 51. In this manner, the shift position of the transmission 34 is switched.

[0039] The steering device 60 controls the steering angle of the steered wheels (left front wheel and right front wheel). The steering device 60 includes an electric power steering ECU (hereinafter referred to as "EPS·ECU") 61, an assist motor 62, and a steering mechanism 63. The EPS·ECU 61 is connected to the assist motor 62 (a drive circuit of the assist motor 62). The assist motor 62 is incorporated in the steering mechanism 63. The steering mechanism 63 is a mechanism for steering the steered wheels. The steering mechanism 63 includes a steering wheel SW, a steering shaft US, and a steering gear mechanism (not shown). The EPS·ECU 61 acquires a steering angle θ from the driving assist ECU 10. The driving assist ECU 10 can appropriately correct the steering angle θ acquired from the steering sensor 2a and transmit it to the EPS·ECU 61. The EPS·ECU 61 can transmit a steering command to the EPS·ECU 61 according to the steering angle θ acquired from the driving assist ECU 10. When the EPS·ECU 61 receives a steering command from the driving assist ECU 10, the EPS·ECU 61 drives the assist motor 62 based on the steering command. In this manner, the steering angle of the steered wheels of the vehicle V (i.e., the steering angle) is controlled.

[0040] (Lane departure prevention function) Next, the lane departure prevention function (LTA) of the vehicle control system 1 will be described. In a situation where the risk reduction function is enabled (F=1), the driving assistance ECU 10 calculates a target driving line Ld based on information acquired from the radar sensor 21, the ultrasonic sensor 22, and the camera 23. As shown in FIG. 2, the target driving line Ld is a line extending approximately parallel to the white line RL (or a curb, a divider, etc.) on the right side of the lane on which the vehicle V is traveling and the white line LL (or a curb, a divider, etc.) on the left side of the lane. Next, the driving assistance ECU 10 calculates the deviation between the front end center position CL of the host vehicle and the target driving line Ld (deviation to the right or left in the width direction of the lane (hereinafter referred to as the "offset value OFS")).

[0041] Then, the driving assistance ECU 10 issues a predetermined warning to the driver in a situation where the offset value OFS (absolute value) exceeds the threshold OFSth. Specifically, the driving assistance ECU 10 causes an audio device of the navigation system 24 to play a predetermined warning sound. Furthermore, the driving assistance ECU 10 controls the steering device 60, the drive device 30, and the braking device 40 so that the offset value OFS coincides with "0". Hereinafter, the control (warning / steering / acceleration / deceleration) for suppressing the host vehicle from deviating from the lane is referred to as "lane departure suppression control."

[0042] (Emergency stop function) Next, the emergency stop function (EDSS) of the vehicle control system 1 will be described. In a situation where the risk reduction function is enabled (F=1), the driving assistance ECU 10 monitors the amount of operation of each operator within a predetermined short period of time (change in the output value of the operator sensor). That is, the driving assistance ECU 10 sequentially acquires the accelerator pedal depression depth AD, the brake pedal depression depth BD, the steering wheel steering angle θ, and the like. When the time during which the operation amounts of all the operators do not change exceeds a threshold value t1, the driving assistance ECU 10 issues a predetermined warning. Furthermore, when the time during which the operation amounts of all the operators do not change exceeds a threshold value t2 from the time when the driving assistance ECU 10 issues the warning, the driving assistance ECU 10 controls the braking device 40, the steering device 60, and the like to stop the vehicle. Furthermore, when the time during which the amount of operation of all the controls does not change from the time the vehicle is stopped exceeds a threshold value t3, the driving assistance ECU 10 reports to a specified server computer (for example, sends the vehicle's position information (latitude and longitude)) via a wireless communication line.

[0043] (Forced activation function) Next, the forced activation function of the vehicle control system 1 will be described. As shown in FIG. 3, when the driving assistance ECU 10 detects that the host vehicle has deviated from the lane in which the host vehicle is traveling (a lane in which the traveling time is equal to or longer than a predetermined time) and has lightly collided with an object such as a guard rail (a light collision that does not activate the airbag device) based on information acquired from the in-vehicle sensor 20 while the risk reduction function is disabled (F=0), the driving assistance ECU 10 forcibly activates the risk reduction function (F=1). That is, even if the switch 2b is not operated, the driving assistance ECU 10 switches the value of the flag F from "0" to "1" (forced activation). Here, the driving assistance ECU 10 determines that the host vehicle has lightly collided with an object when, for example, the following condition X is satisfied: (Condition X) The magnitude of acceleration G is within a specified range GA, and the integral value of the magnitude of acceleration G within a specified time from the point when the magnitude of acceleration G exceeds the lower limit (>0) of the range GA exceeds the threshold value. The range GA is predefined as a range of acceleration that is greater than the acceleration occurring during normal driving conditions (sudden deceleration (front G), sudden acceleration (rear G), sharp turns (lateral G), road vibration (longitudinal G)) and that can be considered as a minor collision.

[0044] Furthermore, when the risk reduction function is forcibly enabled, the driving assistance ECU 10 acquires the speed vs from the speed sensor 25. Then, when the speed vs exceeds the threshold value vsth (i.e., when the host vehicle collides with an object at a relatively high speed), the driving assistance ECU 10 controls the braking device 40, the steering device 60, and the like so that the host vehicle immediately stops. That is, in this case, the driving assistance ECU 10 forcibly stops the host vehicle regardless of whether the driver is operating an operator (forced stop function). The priority of this forced stop function is higher than the lane departure suppression function and the emergency stop function.

[0045] In addition, when the acceleration G exceeds the upper limit value of the range GA (when the impact acting on the vehicle is very large), the driving assistance ECU 10 (or another ECU) controls the braking device 40, steering device 60, etc. so that the vehicle is stopped immediately.

[0046] Next, the operation (programs P1, P2, and P3 that respectively realize the above-mentioned "lane departure prevention function," "emergency stop function," and "forced activation function") of the CPU 10a (hereinafter simply referred to as "CPU") of the driving assistance ECU 10 will be specifically described with reference to Figures 4 to 6. While the engine of the vehicle is operating (when the ignition switch is in the on state), the CPU executes the programs P1, P2, and P3 at a predetermined cycle.

[0047] (Program P1) The CPU starts the execution of the program P1 from step 100 and proceeds to step 101.

[0048] When the CPU proceeds to step 101, it determines whether or not the risk reduction function is enabled (whether or not flag F is "1"). If the risk reduction function is enabled (101: Yes), the CPU proceeds to step 102. On the other hand, if the risk reduction function is disabled (101: No), the CPU proceeds to step 105 and terminates execution of program P1.

[0049] When the CPU proceeds to step 102, it calculates the offset value OFS. Then, the CPU proceeds to step 103.

[0050] When the CPU proceeds to step 103, it determines whether the offset value OFS (absolute value) is equal to or less than the threshold OFSth. If the offset value OFS is equal to or less than the threshold OFSth (103: Yes), the CPU proceeds to step 105. On the other hand, if the offset value OFS exceeds the threshold OFSth (103: No), the CPU proceeds to step 104.

[0051] When the CPU proceeds to step 104, it executes lane departure suppression control (alarm / steering / acceleration / deceleration). Then, the CPU proceeds to step 105.

[0052] (Program P2) The CPU starts the execution of the program P2 from step 200 and proceeds to step 201.

[0053] When the CPU proceeds to step 201, it determines whether or not the risk reduction function is enabled (whether or not flag F is "1"). If the risk reduction function is enabled (201: Yes), the CPU proceeds to step 202. On the other hand, if the risk reduction function is disabled (201: No), the CPU proceeds to step 215 and terminates execution of program P2.

[0054] When the CPU proceeds to step 202, it initializes the measurement time ta (output value) of the timer 10e to "0" and causes the timer 10e to start measuring time. Then, the CPU proceeds to step 203.

[0055] When the CPU proceeds to step 203, it determines whether or not the driver has operated any of the controls (whether or not the operation amounts of all the controls (changes in the output values ​​of each sensor) are "0"). If the driver has not operated any of the controls (if an abnormality has occurred in the driver (203: Yes)), the CPU proceeds to step 204. On the other hand, if the driver has operated any of the controls (203: No), the CPU proceeds to step 215.

[0056] When the CPU proceeds to step 204, it determines whether or not the measured time ta exceeds the threshold value t1. If the measured time ta exceeds the threshold value t1 (204: Yes), the CPU proceeds to step 205. On the other hand, if the measured time ta is equal to or less than the threshold value t1, the CPU returns to step 203.

[0057] When the CPU proceeds to step 205, it causes the navigation system 24 to play a predetermined warning sound. Then, the CPU proceeds to step 206.

[0058] When the CPU proceeds to step 206, it initializes the measurement time ta of the timer 10e to "0" and makes the timer 10e start measuring time again. Then, the CPU proceeds to step 207.

[0059] When the CPU proceeds to step 207, it determines whether or not the driver has operated any of the controls (whether or not the operation amounts of all the controls are "0"). If the driver has not operated any of the controls (207: Yes), the CPU proceeds to step 208. On the other hand, if the driver has operated any of the controls (207: No), the CPU proceeds to step 215.

[0060] When the CPU proceeds to step 208, it determines whether or not the measured time ta exceeds the threshold t2. If the measured time ta exceeds the threshold t2 (208: Yes), the CPU proceeds to step 209. On the other hand, if the measured time ta is equal to or less than the threshold t2, the CPU returns to step 207.

[0061] When the CPU proceeds to step 209, it brakes and stops the host vehicle (emergency stop). That is, the CPU blinks the hazard lights, controls the braking device 40 and the steering device 60, and moves the host vehicle to a safe area (such as a road shoulder or a lane with little traffic) while decelerating the vehicle, and stops the vehicle. Then, the CPU proceeds to step 210. Note that step 209 is executed with priority over program P1.

[0062] When the CPU proceeds to step 210, it initializes the measurement time ta of the timer 10e to "0" and makes the timer 10e start measuring time again. Then, the CPU proceeds to step 211.

[0063] When the CPU proceeds to step 211, it determines whether or not the driver has operated any of the controls (whether or not the operation amounts of all the controls are "0"). If the driver has not operated any of the controls (211: Yes), the CPU proceeds to step 212. On the other hand, if the driver has operated any of the controls (211: No), the CPU proceeds to step 215.

[0064] When the CPU proceeds to step 212, it determines whether or not the measured time ta exceeds the threshold value t3. If the measured time ta exceeds the threshold value t3 (212: Yes), the CPU proceeds to step 213. On the other hand, if the measured time ta is equal to or less than the threshold value t3, the CPU returns to step 211.

[0065] When the CPU proceeds to step 213, it shifts the shift position to the parking position and transmits (reports) predetermined information to the server computer. Then, the CPU proceeds to step 214.

[0066] When the CPU proceeds to step 214, it sets the flag F to "0." This prevents warnings and notifications from being issued frequently. Then, the CPU proceeds to step 215.

[0067] (Program P3) The CPU starts the execution of the program P3 from step 300 and proceeds to step 301.

[0068] When the CPU proceeds to step 301, it determines whether or not the risk reduction function is disabled (whether or not flag F is "0"). If the risk reduction function is disabled (301: Yes), the CPU proceeds to step 302. On the other hand, if the risk reduction function is enabled (301: No), the CPU proceeds to step 312 and terminates execution of program P3.

[0069] When the CPU proceeds to step 302, it determines whether or not the host vehicle has departed from the lane (whether or not the host vehicle has crossed the lane boundary line) based on the information acquired from the camera 23. If the host vehicle has departed from the lane (302: Yes), the CPU proceeds to step 303. On the other hand, if the host vehicle has not departed from the lane, the CPU proceeds to step 312.

[0070] When the CPU proceeds to step 303, it determines whether or not the host vehicle has lightly collided with an object (whether or not condition X is satisfied). If the host vehicle has lightly collided with an object (303: Yes), the CPU proceeds to step 304. On the other hand, if the host vehicle has not lightly collided with an object (303: No), the CPU proceeds to step 312. Note that if the impact acting on the host vehicle is very large (if the acceleration G exceeds the upper limit value of the range GA), the driving assistance ECU 10 executes a program (not shown) that has a higher priority than programs P1 to P3, and immediately stops the host vehicle.

[0071] When the CPU proceeds to step 304, it sets flag F to “1” (forced activation). Then, the CPU proceeds to step 305.

[0072] When the CPU proceeds to step 305, it determines whether or not the speed vs of the host vehicle exceeds the threshold vsth. If the speed vs exceeds the threshold vsth (305: Yes), the CPU proceeds to step 306. On the other hand, if the speed vs is equal to or less than the threshold vsth (305: No), the CPU proceeds to step 312. In this case, the lane departure suppression function that has been forcibly activated controls the drive device 30, the braking device 40, the steering device 60, and the like so that the host vehicle travels along the lane, and if the driver continues not to operate the operation element thereafter, the emergency stop function stops the host vehicle. Note that step 305 is executed immediately after the risk reduction function is forcibly activated, and therefore braking by the emergency stop function (step 209) has not yet started at this point.

[0073] When the CPU proceeds to step 306, it brakes and stops the host vehicle (forced stop). That is, the CPU blinks the hazard lamps and controls the braking device 40, the steering device 60, etc. to decelerate the host vehicle and move it to a safe area (such as a road shoulder or a lane with little traffic) and stop it. Then, the CPU proceeds to step 307. Note that step 306 is executed with priority over programs P1 and P2.

[0074] When the CPU proceeds to step 307, it initializes the measurement time tb (output value) of the timer 10e to "0" and causes the timer 10e to start measuring time. Then, the CPU proceeds to step 308.

[0075] When the CPU proceeds to step 308, it determines whether or not the driver has operated any of the controls (whether or not the operation amounts of all the controls are "0"). If the driver has not operated any of the controls (308: Yes), the CPU proceeds to step 309. On the other hand, if the driver has operated any of the controls (308: No), the CPU proceeds to step 312.

[0076] When the CPU proceeds to step 309, it determines whether or not the measured time tb exceeds the threshold t3. If the measured time tb exceeds the threshold t3 (309: Yes), the CPU proceeds to step 310. On the other hand, if the measured time tb is equal to or less than the threshold t3, the CPU returns to step 308.

[0077] When the CPU proceeds to step 310, it shifts the shift position to the parking position and transmits (reports) predetermined information to the server computer. Then, the CPU proceeds to step 312.

[0078] When the CPU proceeds to step 311, it sets flag F to “0.” Then, the CPU proceeds to step 312.

[0079] (effect) In a vehicle equipped with the above-described vehicle control system 1, the driver can manually switch between an enabled state and a disabled state of the risk reduction function. When the risk reduction function is manually disabled and the host vehicle deviates from the lane and hits an object lightly, the risk reduction function is forcibly enabled. As a result, for example, in a situation in which it is difficult for the driver to drive the host vehicle, the driving assistance ECU 10 assists the driver in driving the host vehicle (LTA). Also, for example, in a situation in which the driver is unable to drive the host vehicle, the driving assistance ECU 10 stops the host vehicle (EDSS). Therefore, the vehicle control system 1 can improve the safety of the vehicle compared to conventional systems.

[0080] Furthermore, if the host vehicle collides lightly with an object at a relatively high speed, the host vehicle is immediately stopped (steps 305 to 311 in FIG. 6), thereby making it possible to further improve the safety of the vehicle.

[0081] The present invention is not limited to the above-described embodiment, and various modifications can be adopted within the scope of the present invention, as described below.

[0082] <Variation 1> In the above embodiment, when the driver presses the switch 2b, the on / off states (enabled and disabled states) of both the lane departure prevention function and the emergency stop function are switched. Alternatively, the on / off states of the lane departure prevention function and the emergency stop function may be individually switched. For example, a switch 2b1 for switching the on / off state of the lane departure prevention function and a switch 2b2 for switching the on / off state of the emergency stop function may be provided. In this case, flags F1 and F2 are used instead of flag F. When the lane departure prevention function is in the on state, flag F1 is "1", and when the lane departure prevention function is in the off state, flag F1 is "0". Also, when the emergency stop function is in the on state, flag F2 is "1", and when the emergency stop function is in the off state, flag F2 is "0".

[0083] In this case, in step 101 of FIG. 4, if the flag F1 is "1", the CPU proceeds to step 102, and if the flag F1 is "0", the CPU proceeds to step 105. In addition, in step 201 of FIG. 5, if the flag F2 is "1", the CPU proceeds to step 202, and if the flag F2 is "0", the CPU proceeds to step 215. In addition, in step 214 of the same figure, the CPU sets the flag F2 to "0". In addition, in this case, in step 301 of FIG. 6, if at least one of the flag F1 and the flag F2 is "0", the CPU proceeds to step 302, and if the flags F1 and F2 are "1", the CPU proceeds to step 312. In addition, in step 304, the CPU sets the flags F1 and F2 to "1". Furthermore, in step 311, the CPU sets the flags F1 and F2 to "0".

[0084] <Variation 2> In the above embodiment, the CPU judges whether or not the driver is abnormal based on whether or not the driver is operating the operator, and determines whether or not to brake the vehicle and issue a report based on the judgment result. Alternatively or in addition to this, an in-vehicle camera that captures the driver may be provided, and the CPU may judge whether or not the driver is abnormal based on an image acquired from the in-vehicle camera. In this case, the driver is allowed to manually switch between an enabled state and a disabled state of a function that judges the driver's state based on the driver image (hereinafter referred to as the "driver image judgment function"). Then, when the vehicle deviates from the lane and slightly collides with an object while the driver image judgment function is disabled, the CPU forcibly activates the driver image judgment function.

[0085] In addition, the vehicle control system 1 may be equipped with a device that automatically disables the lane departure prevention function when it detects that the driver has intentionally changed lanes, and a device that automatically enables the lane departure prevention function when it detects that an abnormality has occurred in the driver. [Explanation of symbols]

[0086] 1...vehicle control system, 2b...switch, 10...driving assistance ECU, 20...vehicle sensor, 30...driving device, 40...braking device, 50...shift switching device, 60...steering device (steering device), F...flag, G...acceleration, V...vehicle

Claims

1. An on-board sensor that outputs information about targets around the vehicle and information about a traveling state of the vehicle; a control device having a risk reduction function including at least one of a lane departure prevention function that controls at least one of a warning device, a drive device, a braking device, and a steering device of the host vehicle based on information acquired from the on-board sensor so as to prevent the host vehicle from departing from the lane in which the vehicle is traveling, and an emergency stop function that stops the host vehicle when an abnormality occurs in the driver; A switching device that switches between an enabled state and a disabled state of the risk reduction function; A vehicle control system comprising: The control device includes: When the magnitude of the acceleration of the host vehicle is within a predetermined range that exceeds the range of acceleration that can occur during normal driving, it is determined that the host vehicle has lightly collided with an object; A vehicle control system configured to forcibly enable the risk reduction function when it is determined that the vehicle has collided lightly with an object while the risk reduction function is disabled by the switching device.

2. 2. The vehicle control system according to claim 1, The control device determines that the vehicle has collided lightly with an object when the magnitude of the acceleration of the vehicle is within a predetermined range that exceeds the range of acceleration that can occur during normal driving, and when the integral value of the magnitude of the acceleration within a predetermined time from the point at which the magnitude of the acceleration of the vehicle exceeds the lower limit of the predetermined range exceeds a threshold value.

3. 3. The vehicle control system according to claim 1, the switching device includes a first operator for manually switching between an enabled state and a disabled state of the lane departure prevention function, and a second operator for manually switching between an enabled state and a disabled state of the emergency stop function, The control device is a vehicle control system in which, when at least one of the lane departure prevention function and the emergency stop function is manually disabled and the vehicle departs from its lane and collides with an object, the control device forcibly enables the manually disabled function.

4. 4. A vehicle control system according to claim 1, The risk reduction function includes the emergency stop function, The control device controls the braking device so that the vehicle stops immediately if the speed of the vehicle exceeds a threshold value between the time the risk reduction function is forcibly enabled and the time braking of the vehicle is initiated by the emergency stop function, regardless of whether an abnormality is occurring with the driver.

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