Vehicle control system

Abstract

The present invention is a vehicle control system that suppresses sudden acceleration of the vehicle caused by a driver's misoperation and avoids accidents to ensure safety even when an obstacle cannot be confirmed in the traveling direction of the vehicle. The vehicle control system includes: a driving assistance unit; a camera unit as a driving environment detection unit; and a driver monitoring system as a driver state monitoring unit. The driving assistance unit includes: an acceleration state detection unit that detects an acceleration state caused by a driver's operation; an expression mutation determination unit that determines a sudden change in the driver's expression; and an acceleration suppression unit that suppresses the acceleration of the vehicle when an object that needs to be avoided from collision is not detected in the traveling direction of the vehicle and it is determined that the driver's expression has suddenly changed immediately after detecting sudden acceleration caused by the driver's operation.

Description

Technical Field

[0001] The present invention relates to a vehicle control system that suppresses acceleration of a vehicle caused by a driver's incorrect operation. Background Art

[0002] In vehicles such as automobiles, various technologies have been proposed to suppress the acceleration of the vehicle and ensure safety when the driver makes an incorrect operation such as stepping on the accelerator pedal and the brake pedal by mistake during the start and / or driving of the vehicle.

[0003] For example, in Patent Document 1 (Japanese Patent No. 5550629), the following technology is proposed: the distance to an obstacle in the traveling direction of the own vehicle is detected, and when the detected distance is within a predetermined distance, if an increase in the acceleration opening is detected, suppression control of the engine output torque is started to prohibit the rapid movement of the own vehicle.

[0004] In addition, in Patent Document 2 (Japanese Patent No. 6075575), the following technology is proposed: on an uphill road, when it is determined that there is an obstacle ahead based on an image captured by a monocular camera, the driving force generated by the power source is suppressed to a driving force that is smaller than the required driving force and does not cause the vehicle to reverse.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Patent No. 5550629

[0008] Patent Document 2: Japanese Patent No. 6075575 Summary of the Invention

[0009] Technical Problem

[0010] However, the prior art as disclosed in Patent Document 1 and / or Patent Document 2 is only premised on the presence of an obstacle ahead, and can also be called the control at the previous stage of collision avoidance control to avoid collision with an obstacle. Therefore, when an obstacle cannot be confirmed in the traveling direction of the vehicle, for example, when the vehicle stops facing the sea or a river, or when the vehicle stops near a cliff, etc., even if the driver makes an incorrect operation and performs an acceleration operation, it is impossible to suppress the sudden acceleration of the vehicle, and it is difficult to ensure safety.

[0011] The present invention has been completed in view of the above circumstances, and an object thereof is to provide a vehicle control system that can suppress the sudden acceleration of the own vehicle caused by a driver's incorrect operation and prevent accidents from occurring to ensure safety even when an obstacle cannot be confirmed in the traveling direction of the own vehicle.

[0012] Technical Solution

[0013] One aspect of the vehicle control system of the present invention includes: a driving environment detection unit that detects the driving environment in the traveling direction of the own vehicle; an acceleration state detection unit that detects the acceleration state caused by the driver's operation; a driver state monitoring unit that monitors the driver's state based on an image of the driver and detects the expression centered on the driver's face; an expression mutation determination unit that determines a sudden change in the driver's expression based on the detection result of the driver state monitoring unit; and an acceleration suppression unit that suppresses the acceleration of the own vehicle when the driving environment detection unit does not detect an object that needs to avoid a collision in the traveling direction of the own vehicle, and when it is determined by the expression mutation determination unit that the driver's expression has suddenly changed immediately after detecting a sudden acceleration caused by the driver's operation through the acceleration state detection unit.

[0014] Technical Effects

[0015] According to the present invention, even when an obstacle cannot be confirmed in the traveling direction of the own vehicle, sudden acceleration of the own vehicle caused by a driver's misoperation can be suppressed, and an accident can be avoided before it occurs, thereby ensuring safety. Brief Description of the Drawings

[0016] Figure 1 It is a schematic configuration diagram of a vehicle control system.

[0017] Figure 2 It is an explanatory diagram showing the configuration of a driver monitoring camera.

[0018] Figure 3 It is an explanatory diagram showing the control timing of acceleration suppression.

[0019] Figure 4 It is a flowchart of an acceleration suppression determination process.

[0020] Symbol Explanation

[0021] 1 Vehicle control system

[0022] 10 Driving assistance unit

[0023] 11a Acceleration state detection unit

[0024] 11b Expression mutation determination unit

[0025] 11c Acceleration suppression unit

[0026] 12 Driving assistance switch

[0027] 13 Driving state detection sensor

[0028] 14 Acceleration sensor

[0029] 20 Camera unit

[0030] 23 Environment recognition unit

[0031] 30 Driver monitoring system

[0032] 31 Driver monitoring camera

[0033] 33 Expression detection unit

[0034] 40 Brake drive control unit

[0035] 50 Steering control unit

[0036] 60 Information notification unit Detailed implementation manner

[0037] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Figure 1 It is a schematic configuration diagram of a vehicle control system. In the present embodiment, Figure 1 the vehicle control system 1 shown is configured centering on a driving assistance unit 10 that serves as a control system mounted on a vehicle to assist a driver's driving operation.

[0038] Specifically, the vehicle control system 1 is configured to include: a driving assistance unit 10, a camera unit 20 as a driving environment detection unit, a driver monitoring system 30 as a driver state monitoring unit for monitoring the state of the driver, a brake drive control unit 40, a steering control unit 50, and an information notification unit 60. Each unit and system includes a computer system and is connected via an in-vehicle network so as to be able to communicate with each other. The computer system includes a computer having a single or multiple processors and its peripheral devices.

[0039] In addition, a driving assistance switch 12, a driving state detection sensor 13, and an acceleration sensor 14 are connected to the driving assistance unit 10. The driving assistance switch 12 is a switch that the driver turns on when wishing to perform driving assistance driving. The driving state detection sensor 13 is a device that detects the driving state of the vehicle (vehicle speed, longitudinal acceleration, steering angle, yaw rate, etc.), and is a general term for sensors such as a vehicle speed sensor, an acceleration sensor, a steering angle sensor, and a yaw rate sensor that detect the driving state of the vehicle. In addition, the acceleration sensor 14 is a sensor that detects the depression amount of the driver's accelerator pedal P (refer to Figure 2 ) as an acceleration opening.

[0040] The camera unit 20 is fixed to the upper center of the front part inside the cab of the vehicle, and includes an in-vehicle camera (stereo camera) composed of a main camera 21a and a sub-camera 21b disposed symmetrically on the left and right across the center in the vehicle width direction, an image processing unit (IPU) 22, and an environment recognition unit 23.

[0041] Each of the two cameras 21a and 21b is internally provided with an imaging element such as a CCD and / or a CMOS, and captures the driving environment in front of the vehicle in different viewpoints, that is, with parallax. Thus, a reference image (main image) and a comparison image (sub-image) required for stereo image processing are obtained. The image signals of the driving environment in front of the vehicle captured by the two cameras 21a and 21b are transmitted to the IPU 22, and after being subjected to predetermined image processing, are transmitted to the environment recognition unit 23.

[0042] The environment recognition unit 23 performs a matching process on the reference image based on the captured image of the main camera 21a and the comparison image based on the captured image of the sub-camera 21b, obtains the pixel offset (parallax) of the corresponding positions between the two images, and converts the pixel offset into luminance data or the like to generate a distance image. According to the principle of triangulation, the point coordinates on the distance image are converted into points in the actual space centered on the vehicle, and the white lines (lane lines) of the road on which the vehicle travels, the three-dimensional objects existing in the traveling direction of the vehicle, the vehicles traveling in front of the vehicle, etc. are three-dimensionally recognized.

[0043] The driver monitoring system 30 includes a driver monitoring camera 31 that captures the driver, an IPU 32 that performs image processing on the image captured by the driver monitoring camera 31, and an expression detection unit 33 that detects the expression centered on the driver's face for each acquired image based on the image of the driver that has been processed by the IPU 32.

[0044] Figure 2 It is an explanatory diagram showing the configuration of the driver monitoring camera. For example, the driver monitoring camera 31 is provided on the instrument panel in front of the driver's seat of the vehicle M. The driver monitoring camera 31 is set to capture the driver D when operating the accelerator pedal P from the front. The image of the driver D captured by the driver monitoring camera 31 is transmitted to the expression detection unit 33 after being processed by the IPU 32.

[0045] The expression detection unit 33 detects the expression of the driver D centered on the face of the driver D for each acquired image based on the image of the driver D. For example, the expression detection unit 33 detects the state of the driver D's face (the opening state of the pupils, the direction of the line of sight, the state of the nostrils and / or the mouth), the state of the arm and / or shoulder holding the steering wheel H, etc. as the expression of the driver D.

[0046] The braking drive control unit 40 controls the driving force generated by the electric motor and / or the internal combustion engine. In addition, it controls the vehicle speed, the switching between forward and reverse, braking, etc. of the vehicle. For example, the braking drive control unit 40 controls the operating state of the engine based on signals from various sensor classes that detect the engine operating state and various control information obtained through the in-vehicle network. In addition, based on the brake switch, the wheel speeds of the four wheels, the steering angle, the yaw rate, and other vehicle information, it controls the braking devices (not shown) of the four wheels independently of the driver's braking operation. Further, the braking drive control unit 40 calculates the braking hydraulic pressure of each wheel based on the braking force of each wheel, thereby performing anti-lock braking control and / or anti-skid control, etc.

[0047] The steering control unit 50 controls the steering torque generated by the electric power steering device (EPS) 51 provided in the steering system based on, for example, the vehicle speed, the driver's steering torque, the steering angle, the yaw rate, and other vehicle information. The control of this steering torque is executed as current control of the electric motor of the EPS device 51, and the EPS device 51 realizes the target steering torque for making the actual steering angle coincide with the target steering angle. The EPS device 51 uses the target steering torque from the steering control unit 50 as the indicated torque, and controls the drive current of the electric motor corresponding to this indicated torque through, for example, PID control.

[0048] The information notification unit 60 controls the output of an alarm to attract the driver's attention and various information presented to the driver when an abnormality occurs in various devices of the vehicle. For example, at least one of visual outputs such as a monitor, a display, and an alarm lamp, and auditory outputs such as a speaker and a buzzer are used to present a warning and / or control information. The information notification unit 60 presents the control state during the running of the vehicle to the driver. In addition, when the driving control including driving assistance is aborted due to the driver's operation, the driving state at that time is presented to the driver.

[0049] In the above vehicle control system 1, if the driving assistance switch 12 is turned on during driving, the driving assistance unit 10 executes various driving assistance controls based on the driving environment in the traveling direction of the vehicle detected by the camera unit 20. For example, as driving assistance controls, the driving assistance unit 10 executes lane keeping control for maintaining the driving position of the vehicle within the lane lines, lane departure prevention control for preventing the vehicle from deviating outside the driving lane, pre-crash braking control for predicting the collision risk and avoiding collision or reducing the collision damage, and adaptive cruise control (ACC) for automatically switching between following driving and constant speed driving according to the detection result of the preceding vehicle.

[0050] In addition, the driving assistance unit 10 monitors the driver's acceleration operation when the vehicle starts and / or during driving, and when a sharp acceleration operation that becomes a sudden acceleration is performed, it determines whether the sharp acceleration operation is caused by the driver's misoperation. Then, when the driving assistance unit 10 determines that the driver has erroneously performed a sharp acceleration operation, it suppresses the acceleration of the vehicle to ensure safety and avoids an accident before the accident occurs. Therefore, the driving assistance unit 10 includes an acceleration state detection unit 11a, an expression mutation determination unit 11b, and an acceleration suppression unit 11c.

[0051] The acceleration state detection unit 11a checks the change in the acceleration opening based on the signal from the acceleration sensor 14 and detects the acceleration state. For example, the acceleration state detection unit 11a calculates the change amount Δα of the acceleration opening α every time a predetermined time is reached, and compares the change amount Δα with the set opening αset. Then, when Δα < αset, the acceleration state detection unit 11a detects a normal acceleration state in which the driver gently steps on the acceleration pedal, and when Δα ≥ αset, it detects a sudden acceleration state in which the driver sharply steps on the acceleration pedal.

[0052] The expression mutation determination unit 11b monitors the driver's expression detected by the expression detection unit 33 of the driver monitoring system 30, and determines whether the driver's expression mutates after a sudden acceleration caused by the driver's sharp acceleration operation. For example, the expression mutation determination unit 11b constructs a database that learns the driver's expression by inputting the driving state of the vehicle and the driver's image into a neural network, etc.

[0053] In this database of the driver's expression, the expression such as the muscle state of the driver's face, the pupil area, the change in the line of sight, the body state of the arm and / or shoulder, and the state of the mouth in the normal acceleration state is recorded, and the expression in the sudden acceleration state is recorded, and the expression in the normal acceleration state and the expression in the sudden acceleration state are learned and distinguished.

[0054] For example, the expression mutation determination unit 11b determines that the driver's expression has mutated when the driver's expression meets any of the following conditions. That is, the expression mutation determination unit 11b, based on the database of the driver's expression, when it recognizes that the muscles of the driver's face are stiff, the pupil area suddenly expands, or the line of sight is concentrated at a point; when it recognizes the stiffness of the body based on the state of the driver's arm and / or shoulder; when it recognizes that the driver is panicked due to an increase in the driver's pupil area and the mouth opening wide, etc., it determines that the driver's expression has mutated.

[0055] When the camera unit 20 does not detect an object (obstacle) that needs to be avoided from collision in the traveling direction of the present vehicle, and after detecting a sudden acceleration caused by the driver's acceleration operation through the acceleration state detection unit 11a, immediately, when the expression mutation determination unit 11b determines that the driver's expression has mutated, the acceleration suppression unit 11c determines that the driver has erroneously performed an acceleration operation and executes acceleration suppression control for suppressing the acceleration of the present vehicle. This acceleration suppression control targets the sudden acceleration state when the present vehicle starts from a stop or during traveling, and is executed by the brake drive control unit 40 when it is determined that the driver's expression has mutated after a set time has elapsed immediately after the driver steps on the acceleration pedal and performs a sudden acceleration.

[0056] Figure 3 is an explanatory diagram showing the control timing of acceleration suppression. If a sudden acceleration caused by the driver's acceleration operation is detected by the acceleration state detection unit 11a, then as Figure 3 shown, the sudden acceleration flag Frac is set to ON (Frac = 1). Then, when it is determined that the driver's expression has mutated by the expression mutation determination unit 11b after a set time Tset has elapsed immediately after the sudden acceleration flag Frac is set to ON, the expression mutation flag Fdrv is set to ON (Fdrv = 1).

[0057] Here, based on considering the reaction time of the driver from when the driver performs a rapid acceleration operation until realizing a misoperation or feeling something abnormal, the set time Tset is set to a time for performing acceleration suppression control intervention as early as possible. For example, it is set to Tset = 1 to 2 sec.

[0058] When both the sudden acceleration flag Frac and the expression mutation flag Fdrv are ON in a state where no obstacle is detected in front of the present vehicle, the acceleration suppression unit 11c sets the acceleration suppression flag Fdec to ON (Fdec = 1) and sends information to the brake drive control unit 40. The brake drive control unit 40 controls the driving force of the engine and / or the electric motor with a preset characteristic according to the acceleration opening degree based on the signal from the acceleration sensor 14 in the normal state where the acceleration suppression flag Fdec is OFF (Fdec = 0). On the other hand, if the acceleration suppression flag Fdec is set to ON, the brake drive control unit 40 executes at least one of the driving force suppression control and the brake control and suppresses the excessive acceleration of the present vehicle, and the driving force suppression control controls the driving force for the acceleration opening degree to be less than normal.

[0059] In this case, the degree of acceleration suppression is adjusted depending on the driving environment in the traveling direction of the own vehicle. For example, when there is an object in the distance in the traveling direction of the own vehicle that does not require collision avoidance at the detection moment, the acceleration suppression unit 11c reduces the driving force or increases the braking force compared to the case where there is no object. In addition, the degree of acceleration suppression is also adjusted according to the available driving space in the traveling direction of the own vehicle. The smaller the available driving space, the stronger the degree of acceleration suppression is set. For example, when the own vehicle stops facing the sea and / or a river, when there is a risk of falling due to a cliff in front of the own vehicle, etc., the degree of acceleration suppression is strengthened compared to the case where there is no object becoming an obstacle on the road ahead.

[0060] Next, the operation of the acceleration suppression of the vehicle control system 1 will be described using the flowchart of the acceleration suppression determination process executed by the driving assistance unit 10. Figure 4 It is a flowchart of the acceleration suppression determination process.

[0061] In the first step S1 of the acceleration suppression determination process, the driving assistance unit 10 reads the information from the camera unit 20 and confirms whether there is an object (obstacle) that needs to be avoided from collision in front of the own vehicle. When there is an obstacle in front of the own vehicle, the driving assistance unit 10 proceeds from step S1 to the process of step S6, and instructs the brake drive control unit 40 and the steering control unit 50 to execute the obstacle avoidance control for avoiding the obstacle.

[0062] On the other hand, when there is no obstacle in front of the own vehicle, the driving assistance unit 10 proceeds from step S1 to the process of step S2, and checks whether the own vehicle is in a sudden acceleration state with reference to the sudden acceleration flag Frac. As described above, the sudden acceleration flag Frac is a flag that is set to ON when a sudden acceleration state is detected based on the change amount of the acceleration opening calculated each time a predetermined time is reached.

[0063] When not in the sudden acceleration state in step S2 (Frac = 0), the driving assistance unit 10 proceeds to the process of step S5, and instructs the brake drive control unit 40 and the steering control unit 50 to execute normal driving control.

[0064] On the other hand, when in the sudden acceleration state in step S2 (Frac = 1), the driving assistance unit 10 further refers to the facial expression mutation flag Fdrv in step S3 and determines whether the facial expression of the driver has mutated immediately after the sudden acceleration. As described above, the facial expression mutation flag Fdrv is a flag that is set to ON when the driver monitoring system 30 determines that the detected facial expression of the driver has mutated after a set time Tset (for example, Tset = 1 to 2 sec) has elapsed immediately after the sudden acceleration state is determined.

[0065] When there is no change in the driver's expression immediately after a sudden acceleration (Frac = 1, Fdrv = 0), the driving assistance unit 10 proceeds from step S3 to step S5 and performs normal driving control. On the other hand, when there is a sudden change in the driver's expression immediately after a sudden acceleration (Frac = 1 and Fdrv = 1), the driving assistance unit 10 proceeds from step S3 to the process of step S4, and instructs the brake drive control unit 40 to perform acceleration suppression control. This acceleration suppression control is executed as control of at least one of the driving force control and the brake control.

[0066] Thus, in the present embodiment, when no obstacle is detected in the traveling direction of the vehicle and it is determined that there is a sudden change in the driver's expression immediately after detecting a sudden acceleration caused by the driver's operation, the acceleration of the vehicle is suppressed. Therefore, it is possible to prevent the vehicle from being over-accelerated due to the driver's misoperation and to ensure safety and avoid an accident before it occurs.

[0067] In particular, in the case where the vehicle stops facing the sea and / or river where there is no three-dimensional object in front, or in the case where the vehicle stops at a place where there is a space in front of a cliff or the like, it is possible to effectively suppress a sudden acceleration caused by the driver's misoperation. Moreover, when no obstacle is detected in the traveling direction of the vehicle, a sudden acceleration caused by normal driving operation is allowed, and thus, discomfort is not given to the driver.

Claims

1. A vehicle control system, characterized in that, Comprising: A driving environment detection unit that detects the driving environment in the traveling direction of the vehicle; An acceleration state detection unit that detects the acceleration state caused by the driver's operation; A driver state monitoring unit that monitors the driver's state based on an image obtained by photographing the driver and detects the expression centered on the driver's face; An expression mutation determination unit that determines the mutation of the driver's expression based on the detection result of the driver state monitoring unit; And An acceleration suppression unit that suppresses the acceleration of the vehicle when the driving environment detection unit does not detect an object that needs to avoid a collision in the front in the traveling direction of the vehicle, and immediately after detecting a sudden acceleration caused by the driver's operation through the acceleration state detection unit, the expression mutation determination unit determines that the driver's expression has mutated, and when there is an object in the front in the traveling direction of the vehicle that does not need to avoid a collision at the detection moment, enhances the degree of acceleration suppression.

2. The vehicle control system according to claim 1, wherein The expression mutation determination unit determines that the driver's expression has mutated when any one of stiffness of the driver's face, fixation of the line of sight at a point, and stiffness of the body is recognized.

3. The vehicle control system according to claim 1, wherein The acceleration suppression unit targets the sudden acceleration state when the vehicle starts from a stop or during driving.

4. The vehicle control system according to claim 2, wherein The acceleration suppression unit targets the sudden acceleration state when the vehicle starts from a stop or during driving.

5. The vehicle control system according to any one of claims 1 to 4, wherein The acceleration suppression unit enhances the degree of acceleration suppression as the drivable space in the traveling direction of the vehicle becomes smaller.

6. The vehicle control system according to claim 1, wherein The "immediately after" is after a predetermined time, and the predetermined time is a time for controlling the acceleration suppression as early as possible on the basis of considering the driver's reaction time from when the driver realizes a misoperation or feels something abnormal.

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