JP5374959B2 - Vehicle travel support device - Google Patents

Description

  The present invention relates to a vehicle travel support technology that avoids contact between an own vehicle and an obstacle.

Conventionally, as this type of technology, for example, there is a technology described in Patent Document 1. In this prior art, when an obstacle that hinders the traveling of the host vehicle is detected, the host vehicle is turned in the lateral direction of the obstacle by steering control, and then the host vehicle is moved from the lateral direction of the obstacle. By turning the vehicle in the direction of travel, the vehicle passes through the side of the obstacle.
JP-A-2005-173663

By the way, in the technique for avoiding the contact with the obstacle by the steering control as described above, the steering control is generally completed before the own vehicle overlaps the obstacle in the vehicle width direction.
Therefore, when turning the own vehicle from the side direction of the obstacle to the original traveling direction, the driver may feel a sense of incongruity as if the own vehicle is heading toward the obstacle.
This invention is made paying attention to the above points, and makes it a subject to suppress a driver | operator's discomfort when performing obstacle avoidance control.

  In order to solve the above-described problem, according to the present invention, when the own vehicle starts to overlap the obstacle in the vehicle width direction, at least one of the yaw angle of the own vehicle and the yaw rate of the own vehicle moves away from the obstacle. The behavior of the vehicle was controlled so as to be in the direction.

According to the present invention, when the own vehicle starts to overlap the obstacle in the vehicle width direction, the own vehicle turns around in a direction away from the obstacle. For this reason, it is possible to prevent the driver from feeling that the host vehicle is heading toward the obstacle.
As a result, when the obstacle avoidance control is performed, the driver's uncomfortable feeling can be suppressed.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In the present embodiment, an example in which the driving support apparatus according to the present invention is applied to a vehicle is shown.
This vehicle detects an obstacle SM that is an obstacle to travel of the host vehicle SW, and performs steering control so as to avoid contact between the host vehicle SW and the obstacle SM.
Hereinafter, this steering control is also referred to as “obstacle avoidance control”.

(Constitution)
First, the structure of the vehicle of this embodiment is demonstrated.
FIG. 1 is a schematic configuration diagram illustrating a vehicle according to the present embodiment.
The vehicle 1 includes a braking unit 2, a steering unit 3, an external environment detection unit 4, a vehicle state detection unit 5, and a main control unit 6.
The braking unit 2 includes a brake pedal 8, a booster 9, a master cylinder 10, and wheel cylinders 11FL to 11RR. And according to the depression amount of the brake pedal 8 by a driver | operator, the braking fluid pressure | voltage-risen with the master cylinder 10 is supplied to each wheel cylinder 11FL-11RR. Thereby, a braking force is generated in each of the wheels 7FL to 7RR.

The braking unit 2 includes a braking fluid pressure control unit 12 interposed in a hydraulic pipe that connects the master cylinder 10 and the wheel cylinders 11FL to 11RR.
The brake fluid pressure control unit 12 controls the brake fluid pressures of the wheel cylinders 11FL to 11RR in accordance with a brake fluid pressure command (described later) output from the main control unit 6. Thereby, the braking force of each wheel 7FL-7RR is controlled.

The steering unit 3 includes a steering wheel 13 and a steering column 14. And the steering column 14 rotates according to the operation amount of the steering wheel 13 by the driver. Thereby, a turning angle is generated in each of the wheels 7FL to 7RR.
In addition, the steering unit 3 includes a steering control unit 15 disposed on the steering column 14.
The steering control unit 15 applies a steering torque to the steering column 14 in accordance with a steering command (described later) output from the main control unit 6. Thereby, the turning angle of each wheel 7FL-7RR is controlled.

The external environment detection unit 4 includes a laser radar 16, a CCD camera 17, and an external environment detection unit 18. The laser radar 16 and the CCD camera 17 output detection result information to the external environment detection unit 18.
The laser radar 16 irradiates laser light in front of the vehicle 1 and receives reflected light reflected by an object in front of the vehicle 1. The CCD camera 17 captures an image of the condition of the traveling road ahead of the vehicle 1.
The external environment detection unit 18 detects the presence / absence and position information of an obstacle SM (for example, another vehicle, a pedestrian, etc.) that obstructs the traveling of the host vehicle SW in front of the host vehicle SW. The presence / absence of the obstacle SM and the detection of the position information are performed based on the result of receiving the reflected light by the laser radar 16 and the result of imaging the condition of the traveling path by the CCD camera 17.

Further, when there is an obstacle SM, the external environment detection unit 18 has obstacle coordinates (St, Sy), a distance between the host vehicle SW and the obstacle SM, a lateral speed Sv of the obstacle SM, The travel path environment and travel path area are also detected. The information on the presence / absence of the obstacle SM, the obstacle coordinates (St, Sy), the distance between the host vehicle SW and the obstacle SM, the lateral speed Sv of the obstacle SM, the road environment, and the road area. Output to the main control unit 6.
Here, the obstacle coordinates (St, Sy) are the positions of the obstacle SM expressed in the vehicle coordinate system (x, y) with the own vehicle SW as a reference. The vehicle coordinate system is a coordinate system having an x axis and ay axis that are orthogonal to each other. The center of gravity when the host vehicle SW is viewed in plan is the origin (0.0), the forward direction of the host vehicle SW is the positive direction of the x-axis, and the right direction of the host vehicle SW is the positive direction of the y-axis.

The lateral speed Sv of the obstacle SM is a y-axis direction component of the moving speed of the obstacle SM.
The vehicle state detection unit 5 includes a throttle opening sensor 19, a brake depression amount sensor 20, a brake fluid pressure sensor 21, a steering angle sensor 22, wheel speed sensors 23FL to 23RR, a yaw rate sensor 24, and an acceleration sensor 25. These sensors output detection result information to the main control unit 6.

  The throttle opening sensor 19 detects the throttle opening. The brake depression amount sensor 20 detects the depression amount of the brake pedal 8. The brake fluid pressure sensor 21 detects the brake fluid pressure boosted by the master cylinder 10. The steering angle sensor 22 detects the steering angle of the steering wheel 13. Wheel speed sensors 23FL-23RR detect the rotational speed of each wheel 7FL-7RR. The yaw rate sensor 24 detects the yaw rate Yr of the vehicle 1. The acceleration sensor 25 detects the acceleration in the front-rear direction and the left-right direction of the vehicle 1.

The main control unit 6 is composed of a microprocessor.
The microprocessor includes an integrated circuit including an A / D conversion circuit, a D / A conversion circuit, a central processing unit, and a memory. Then, obstacle avoidance control is executed according to the program stored in the memory. In the obstacle avoidance control, a braking command is output to the braking unit 2 and a steering command is output to the steering unit 3 based on various information output by the external environment detection unit 4 and the vehicle state detection unit 5.

(Main control unit configuration)
Next, the configuration of the main control unit 6 will be described in detail.
FIG. 2 is a block flow diagram showing a functional configuration of the main control unit 6.
As shown in FIG. 2, the main control unit 6 includes an external environment detection means 30, an obstacle position detection means 31, a host vehicle state detection means 32, an obstacle arrival time calculation means 33, an obstacle width calculation means 34, an avoidance margin. A region calculation means 35 is provided. In addition, an avoidance target point calculation means 36, a target point arrival time calculation means 37, a vehicle yaw motion control restriction means 38, an avoidance route calculation means 39, and an actuator control means 40 are provided.

The external environment detection means 30 acquires information on the presence / absence of the obstacle SM and information on the traveling road area output from the external environment detection unit 18.
The obstacle position detection means 31 acquires information on the obstacle coordinates (St, Sy) output from the external environment detection unit 18 and information on the lateral speed Sv of the obstacle SM.
The own vehicle state detection means 32 acquires information on the rotational speeds of the wheels 7FL to 7RR output from the wheel speed sensors 23FL to 23RR and information on the yaw rate Yr output from the yaw rate sensor 24. In addition, the host vehicle state detection means 32 calculates the host vehicle speed Vc based on the acquired information on the rotational speeds of the wheels 7FL to 7RR.

The own vehicle state detection means 32 also includes information on the throttle opening output from the throttle opening sensor 19, information on the depression amount output by the brake depression amount sensor 20, and the braking fluid pressure output by the braking fluid pressure sensor 21. Get information. The own vehicle state detection means 32 calculates the braking / driving force of each of the wheels 7FL to 7RR based on the acquired information on the throttle opening, the information on the amount of depression, and the information on the brake fluid pressure.
The obstacle arrival time calculating means 33 calculates the obstacle arrival time TTC. The obstacle arrival time TTC is the time until the host vehicle SW reaches the position of the obstacle SM in the x-axis direction.
The obstacle arrival time TTC is calculated based on the information on the obstacle coordinates (St, Sy) acquired by the obstacle position detecting unit 31, the own vehicle speed Vc, the braking / driving force, and the yaw rate Yr acquired by the own vehicle state detecting unit 32. Based on information.

For example, the obstacle arrival time TTC [sec.] Is calculated based on the information on the obstacle coordinates (St [m], Sy [m]) and the information on the host vehicle speed Vc [m / sec.] (1) Follow the formula.
TTC = St / Vc (1)
The obstacle width calculation means 34 calculates the obstacle width Sh. The obstacle width Sh is a y-axis direction component of the end of the obstacle moving area P on the obstacle moving direction side.
The obstacle moving area P is an area where the obstacle SM is likely to move.
The obstacle moving region P is a quadrangular region in plan view surrounded by two sides parallel to the x axis and two sides parallel to the y axis.

  Specifically, the obstacle width calculation unit 34 first calculates the obstacle coordinates (St, Sy) acquired by the obstacle position detection unit 31, the information about the horizontal speed Sv of the obstacle SM, and the obstacle arrival time calculation. Based on the obstacle arrival time TTC calculated by the means 33, the obstacle movable position is calculated. The obstacle movable position is a y-axis direction component of a position where the obstacle SM may move after the obstacle arrival time TTC. Next, the obstacle width calculating means 34 calculates the obstacle width Sh by adding the y-axis direction width and the margin of the obstacle SM to the obstacle movable position.

For example, the obstacle width Sh [m] is calculated by calculating the obstacle coordinates (St [m], Sy [m]), the lateral speed Sv [m / sec.] Of the obstacle SM, and the obstacle arrival time TTC [sec. ], According to the following formula (2).
Sh = [Sy + (Sv x TTC)] x Sk (2)
Here, Sk is a coefficient set in accordance with the width in the y-axis direction and the margin of the obstacle SM.
Further, the obstacle width calculating means 34 determines a point (Vx, Vy) where the host vehicle SW reaches after the obstacle arrival time TTC according to the following equation (3) based on the yaw rate Yr, the own vehicle speed Vc, and the obstacle arrival time TTC. calculate.
(Vx, Vy) = TTC × Vc × Yr (3)
The y-axis direction component Vy of the point (Vx, Vy) is hereinafter referred to as “lateral movement amount”.

The avoidance margin area calculation means 35 calculates the avoidance margin area Q. The avoidance margin area Q is an area where traveling is permitted in the traveling road area from the viewpoint of avoiding contact with the obstacle SM.
Specifically, the avoidance margin area calculating unit 35 firstly includes information on the travel road area acquired by the external environment detecting unit 30, the own vehicle speed Vc acquired by the own vehicle state detecting unit 32, the braking / driving force, and the yaw rate Yr. Get information. Next, the avoidance margin calculation means 35 calculates the avoidance allowance based on the acquired travel road area, own vehicle speed Vc, braking / driving force, yaw rate Yr information, and the obstacle width Sh calculated by the obstacle width calculation means 34. Area Q is calculated.
The avoidance margin area calculation means 35 executes calculation processing for confirming that the calculated avoidance margin area Q is an area in which the host vehicle SW can travel appropriately by the obstacle avoidance control.

FIG. 3 is a flowchart of calculation processing for confirming the traveling possibility of the host vehicle.
FIG. 4 is an explanatory diagram for explaining a method for confirming the traveling possibility of the host vehicle.
First, in step S11, as shown in FIGS. 4 (a) and 4 (b), it is determined whether the obstacle moving area P exists on the left or right side of the traveling road area. If it is determined that the obstacle moving area P exists on the left side of the traveling road area (left side), the process proceeds to step S12. On the other hand, if it is determined that the obstacle moving area P exists on the right side of the traveling road area (right side), the process proceeds to step S13.

Next, in step S12, the coordinates (x1, y1) of the corner on the right end of the obstacle moving area P and on the own vehicle SW side are detected. Further, the coordinates (x2, y2) of the point closest to the coordinates (x1, y1) at the right end of the traveling road area are detected. Then, when the detection of the coordinates (x1, y1) (x2, y2) is finished, the process proceeds to step S14.
On the other hand, in step S13, the coordinates (x1, y1) of the corner on the left end of the obstacle moving area P and on the own vehicle SW side are detected. Further, the coordinates (x2, y2) of the point closest to the coordinates (x1, y1) at the left end of the traveling road area are detected. Then, when the detection of the coordinates (x1, y1) (x2, y2) is finished, the process proceeds to step S14.

Next, in step S14, based on the yaw rate Yr, the host vehicle speed Vc, and the obstacle arrival time TTC, a point (Vx, Vy) at which the host vehicle SW reaches after the obstacle arrival time TTC is calculated according to the equation (3).
Next, in step S15, it is determined whether or not the point (Vx, Vy) that the host vehicle SW reaches after the obstacle arrival time TTC is between (x1, y1) and (x2, y2). When it is determined that the point (Vx, Vy) is between (x1, y1) and (x2, y2) (Yes), the process proceeds to step S16. On the other hand, if it is determined that the point (Vx, Vy) is not between (x1, y1) and (x2, y2) (No), the process proceeds to step S17.

Next, in step S16, it is determined that the calculated avoidance margin area Q is an area that can be traveled appropriately by the obstacle avoidance control.
Accordingly, it is determined that there is an area where the host vehicle SW can travel by the obstacle avoidance control on the side of the obstacle SM.
On the other hand, in step S17, it is determined that the calculated avoidance margin area Q is not an area that can be traveled appropriately by the obstacle avoidance control.
The avoidance margin area calculation means 35 prohibits the execution of the obstacle avoidance control when it is determined that the avoidance margin area Q is not an area that can be traveled appropriately by the obstacle avoidance control.
The avoidance target point calculation means 36 calculates avoidance target point coordinates Mp. The avoidance target point coordinate Mp is an x-axis direction component of the final point at which the obstacle avoidance control ends. The avoidance target point coordinates Mp are set ahead of the obstacle moving area P in the traveling direction of the host vehicle SW.

FIG. 5 is a flowchart of a calculation process for calculating the avoidance target point coordinates Mp.
FIG. 6 is an explanatory diagram for explaining a method of calculating the avoidance target point coordinates Mp.
First, in step S21, information on the travel road area acquired by the external environment detection unit 30 and information on the obstacle coordinates (St, Sy) acquired by the obstacle position detection unit 31 are acquired. In addition, the vehicle speed Vc, braking / driving force, yaw rate Yr information acquired by the host vehicle state detection unit 32 and obstacle arrival time TTC calculated by the obstacle arrival time calculation unit 33 are acquired. Next, as shown in FIG. 6, the information such as the acquired obstacle coordinates (St, Sy), the obstacle width Sh detected by the obstacle width calculation means 34, and the avoidance margin area calculated by the avoidance margin area calculation means 35 Based on Q, a temporary avoidance target point coordinate Xa is calculated.

  Next, in step S22, the multiplication result (TTC × Vc) of the own vehicle speed Vc acquired by the own vehicle state detection means 32 and the obstacle arrival time TTC calculated by the obstacle arrival time calculation means 33 is a temporary avoidance target point. It is determined whether or not the coordinate is smaller than Xa. And when it determines with TTC * Vc being smaller than Xa (Yes), it transfers to step S23. On the other hand, if it is determined that TTC × Vc is equal to or greater than Xa (No), the process proceeds to step S24.

Next, in step S23, the avoidance target point coordinates Mp are obtained by multiplying the host vehicle speed Vc and the obstacle arrival time TTC (TTC × Vc).
On the other hand, in step S24, the temporary avoidance target point coordinate Xa is set as the avoidance target point coordinate Mp.
The target point arrival time calculating means 37 calculates the target point arrival time TTCm. The target point arrival time TTCm is the time required for the host vehicle SW to reach the avoidance target point coordinate Mp.

The target point arrival time TTCm is calculated by the target point arrival time calculating unit 37 using the own vehicle speed Vc, braking / driving force, yaw rate Yr information detected by the host vehicle state detecting unit 32, and the avoidance target point calculating unit 36. This is performed based on the avoidance target point coordinates Mp.
For example, the target point arrival time TTCm [sec.] Is calculated according to the following equation (4) based on the host vehicle speed Vc [m / sec.] And the avoidance target point coordinates Mp [m].
TTCm = Mp / Vc (4)

The vehicle yaw motion control limiting means 38 calculates a yaw motion limit value. The yaw motion limit value is an upper limit value of the yaw rate Yr when the vehicle 1 passes through the coordinates (x1, y1) detected by the avoidance margin area calculation means 35, which is used for obstacle avoidance control.
The yaw motion limit value is calculated based on the avoidance margin area Q calculated by the avoidance margin area calculation means 35.
The avoidance route calculation means 39 calculates a target steering angle pattern. The target steering angle pattern is time-series data of target steering angles for obstacle avoidance used for obstacle avoidance control.
Here, with respect to the steering angle, the clockwise direction of the steering wheel 13 is a positive direction and the counterclockwise direction of the steering wheel 13 is a negative direction.

  Specifically, the avoidance route calculation unit 39 firstly includes information on the own vehicle speed Vc, braking / driving force, and yaw rate Yr acquired by the own vehicle state detection unit 32, and the obstacle width Sh calculated by the obstacle width calculation unit 34. To get. Next, a target steering angle pattern is calculated based on the acquired information, the yaw motion limit value calculated by the vehicle yaw motion control limiting means 38, and the avoidance target point coordinates Mp calculated by the avoidance target point calculation means 36.

FIG. 7 is an explanatory diagram for explaining a method of calculating a target steering angle pattern.
For example, the target steering angle pattern is calculated using a vehicle model unit 41, a yaw angle limiting unit 42, and a route calculation unit 43 as shown in FIG.
The vehicle model unit 41 acquires the target steering angle pattern stored in the memory based on the obstacle arrival time TTC calculated by the obstacle arrival time calculation means 33 and the lateral movement amount Vy calculated by the obstacle width calculation means 34.

FIG. 8 is an explanatory diagram for explaining the target steering angle pattern.
In the target steering angle pattern, the host vehicle SW is moved in the y-axis direction by the lateral movement amount Vy after the obstacle arrival time TTC, and the traveling direction of the host vehicle SW is more than the obstacle movement region P after (TTC × 2 + α) time. This is time-series data for causing the host vehicle SW to reach the target arrival point on the front side. It is also information indicating an avoidance route in which the host vehicle SW can travel while avoiding contact with the obstacle SM.

As a result, when the host vehicle SW and the obstacle SM start to overlap in the vehicle width direction, the yaw rate of the host vehicle SW is generated in a direction in which the host vehicle SW moves away from the obstacle SM.
As shown in FIG. 8, the target steering angle pattern is stored in the memory in the form of a sine function that represents a change in the target steering angle with time as a sine wave, or a polynomial that approximates the sine wave.
Α is a constant set according to the delay of the sensor sampling period. For example, when the maximum delay of the sensor sampling period is 300 [msec.], The α is set to 500 [msec.].
The yaw angle limiting unit 42 executes a calculation process for correcting the target steering angle pattern acquired by the vehicle model unit 41.

FIG. 9 is a flowchart of a calculation process for correcting the target steering angle pattern.
FIG. 10 is an explanatory diagram for explaining a method of correcting the target steering angle pattern.
First, in step S31, it is determined whether the target steering angle pattern, that is, the leading data of the time-series data of the target steering angle is a positive or negative value. If it is determined that the leading data is a positive value (positive value), the process proceeds to step S32. On the other hand, if it is determined that the leading data is a negative value (negative value), the process proceeds to step S33.

Next, in step S32, first, a data string from the top data to the data corresponding to the obstacle arrival time TTC is detected from the time series data. Next, as shown in range A in FIG. 10, the steering angle in the detected data string is decreasing and the steering angle smaller than a predetermined threshold value a (> 0) is replaced with the threshold value a. To do.
By this replacement, the steering angle of the steering wheel 13 exceeds the neutral position until the obstacle arrival time TTC elapses from the start of the obstacle avoidance control, and the host vehicle SW is steered in a direction approaching the obstacle SM. Can be prevented. As a result, the yaw rate can be prevented from occurring in the direction in which the host vehicle SW approaches the obstacle SM.
The threshold value a is set so that the yaw rate Yr of the host vehicle SW is equal to or less than the yaw motion limit value when the obstacle arrival time TTC has elapsed since the start of the obstacle avoidance control.

FIG. 11 is an explanatory diagram for explaining a modification of the method for correcting the target steering angle pattern.
In the present embodiment, an example is shown in which time series data up to the obstacle arrival time TTC is replaced with the threshold value a or less, but other configurations may be adopted. it can. For example, as shown in FIG. 11, the entire target steering angle pattern may be corrected so that each value of the time series data becomes a positive value at least until the obstacle arrival time TTC.

Next, in step S33, first, a data string from the head data to data for the obstacle arrival time TTC is detected from the time series data. Next, in the detected data string, the steering angle which is increasing and is larger than the threshold value -a is replaced with the threshold value -a.
FIG. 12 is an explanatory diagram for describing a method of extracting time-series data of the steering angle.
As shown in FIG. 12, the route calculation unit 43 obtains from the target steering angle pattern corrected by the yaw angle limiting unit 42, that is, from the time series data of the steering angle to the data corresponding to the target point arrival time TTCm. Extract data columns.

When the time (TTC × 2 + α) represented by the time series data of the target steering angle pattern is shorter than the target point arrival time TTCm, the steering angle by the target steering angle pattern is used as a data string extracted from the target steering angle pattern. All of the time series data is used.
The actuator control means 40 outputs a steering command to the steering control unit 15. The steering command is a command for causing the steering angle of the steering wheel 13 to follow the time-series data of the steering angle extracted from the target steering angle pattern by the route calculation unit 43. It is also a command for controlling the behavior of the host vehicle SW so that the host vehicle SW travels along the avoidance route indicated by the time series data.

In the present embodiment, the example in which the obstacle avoidance control is realized by controlling the steering angle of the steering wheel 13 is shown, but other configurations may be adopted. For example, obstacle avoidance control can be realized by performing braking / driving force control instead of steering angle control. Specifically, the actuator control means 40 generates a yaw rate due to a difference in braking force between the left and right wheels, and outputs a braking fluid pressure command to the braking fluid pressure control unit 12 so that obstacle avoidance control is realized.
The actuator control means 40 determines the end of the obstacle avoidance control based on the actual steering angle pattern, information on the vehicle speed Vc, and the obstacle coordinates (St, Sy).

  In this embodiment, the time series data for the target point arrival time TTCm is extracted from the target steering angle pattern, and the example in which all the steering angles of the steering wheel 13 follow the extracted time series data is shown. A configuration can also be adopted. For example, one piece of data at the time of control execution can be extracted from the target steering angle pattern, and the steering angle of the steering wheel 13 can be made to follow the extracted one piece of data. Each time the extraction of one data and the tracking of the steering angle of the steering wheel 13 to the one data is finished, a new target steering angle pattern can be calculated, and the extraction and the tracking of the steering angle can be repeatedly executed. .

(Operation)
Next, the operation of this embodiment will be described.
First, it is assumed that the driver performs a collision avoidance control start operation on the main control unit 6 while the vehicle 1 is traveling. Then, the main control unit 6 acquires information on the presence / absence of the obstacle SM and information on the travel path area from the external environment detection unit 18. When the acquired information indicates that there is no obstacle SM, the operation of acquiring these information is repeated.
Here, it is assumed that a pedestrian jumps out on the traveling road ahead of the host vehicle SW, and the main control unit 6 detects the pedestrian as an obstacle SM that obstructs the traveling of the host vehicle SW. Then, the main control unit 6 acquires information on the obstacle coordinates (St, Sy) and information on the lateral speed Sv of the obstacle SM from the external environment detection unit 18.

When these pieces of information are acquired, the main control unit 6 subsequently acquires information about the rotational speeds of the wheels 7FL to 7RR, information about braking / driving forces, and information about the yaw rate Yr from the wheel speed sensors 23FL to 23RR. Further, the main control unit 6 calculates the host vehicle speed Vc based on the acquired information on the rotational speeds of the wheels 7FL to 7RR.
When the calculation of the host vehicle speed Vc is finished, the main control unit 6 receives the throttle opening information from the throttle opening sensor 19, the depression amount information from the brake depression amount sensor 20, and the braking fluid pressure information from the braking fluid pressure sensor 21. get. Further, the main control unit 6 calculates the braking / driving force of each of the wheels 7FL to 7RR based on the acquired throttle opening information, the depression amount information, and the braking fluid pressure information.

When the calculation of the braking / driving force is finished, the main control unit 6 until the host vehicle SW reaches the position of the obstacle SM in the x-axis direction based on the information on the obstacle coordinates (St, Sy) and the information on the host vehicle speed Vc. The obstacle arrival time TTC is calculated.
When the calculation of the obstacle arrival time TTC is finished, the main control unit 6 determines that the y of the obstacle movement region P is based on the obstacle coordinates (St, Sy), the lateral speed Sv of the obstacle SM, and the obstacle arrival time TTC. The obstacle width Sh, which is the coordinate of the axial end, is calculated.

When the calculation of the obstacle width Sh is completed, the main control unit 6 is an area within the traveling road area based on the host vehicle speed Vc, the yaw rate Yr, and the obstacle arrival time TTC, and the viewpoint of avoiding contact with the obstacle SM. The avoidance margin area Q where the vehicle is allowed to travel is calculated.
When the calculation of the avoidance margin area Q is completed, the main control unit 6 sets the avoidance target point coordinate Mp, which is the x-axis direction component of the point at which the obstacle avoidance control ends based on the host vehicle speed Vc and the obstacle arrival time TTC. calculate.
Here, the avoidance target point coordinates Mp are set ahead of the obstacle moving area P in the traveling direction of the host vehicle SW.

When the calculation of the avoidance target point coordinates Mp is completed, the main control unit 6 takes the target point arrival time until the own vehicle SW reaches the position of the avoidance target point coordinates Mp based on the own vehicle speed Vc and the avoidance target point coordinates Mp. TTCm is calculated.
When the calculation of the target point arrival time TTCm is completed, the lower limit of the yaw angle of the host vehicle SW at which the main control unit 6 starts passing the obstacle SM laterally based on the avoidance margin area Q. A yaw motion limit value Yra is set to limit.
When the setting of the yaw motion limit value Yra is completed, the main control unit 6 determines that the host vehicle SW and the obstacle are based on the host vehicle speed Vc, the yaw rate Yr, the obstacle width Sh, the yaw motion limit value Yra, and the avoidance target point coordinates Mp. A target steering angle pattern that avoids contact with the SM is calculated.

  In this target steering angle pattern, when obstacle avoidance control is started, first, the steering wheel 13 is steered in a direction in which the host vehicle SW moves away from the obstacle SM. Further, the steering in the direction continues until the own vehicle SW passes the side of the obstacle SM. That is, until the own vehicle SW passes the side of the obstacle SM, the steering angle of the steering wheel 13 exceeds the neutral position, and the steering in the direction in which the own vehicle SW approaches the obstacle SM is prohibited.

When the calculation of the target steering angle pattern is finished, the main control unit 6 outputs a steering command for causing the steering angle of the host vehicle SW to follow the target steering angle pattern to the steering control unit 15.
When the output of the steering command is finished, the steering control unit 15 starts obstacle avoidance control according to the steering command, and applies steering torque to the steering column 14.
When the obstacle avoidance control starts, first, the steering wheel 13 steers in a direction in which the host vehicle SW moves away from the obstacle SM. Further, by steering the steering wheel 13, the steered wheels 7FL and 7FR of the host vehicle SW are steered in a direction in which the host vehicle SW moves away from the obstacle SM. Further, by turning the steered wheels 7FL and 7FR, a yaw rate is generated in the own vehicle SW in a direction in which the own vehicle SW is away from the obstacle SM, and the own vehicle SW is in a direction in which the own vehicle SW is away from the obstacle SM. Turn around and run in that direction as shown in FIG.

Further, when the steering is continued and the own vehicle SW passes the side of the obstacle SM, the yaw rate is generated in the direction in which the own vehicle SW moves away from the obstacle SM.
As a result, when the host vehicle SW passes the side of the obstacle SM, it is possible to prevent the driver from feeling that the host vehicle SW is approaching the obstacle SM.
Moreover, after the own vehicle SW passes the side of the obstacle SM, the steering wheel 7FL, 7FR starts to be switched back, and the front-rear direction of the own vehicle SW becomes parallel to the tangential direction of the travel path.

FIG. 13 is an explanatory diagram for explaining a comparative example.
Incidentally, when the avoidance target point coordinate Mp is set to the front side of the traveling direction of the host vehicle SW with respect to the obstacle moving area P, when the steering wheel 7FL, 7FR is switched back, the host vehicle SW is obstructed. The driver feels uncomfortable as if he is heading toward SM.
Here, in this embodiment, the external environment detection unit 4, the main control unit 6, the laser radar 16, the CCD camera 17, and the external environment detection means 30 of FIG. 2 are the road area detection means and the obstacle position detection means. Configure. Similarly, the main control unit 6 in FIG. 1, the wheel speed sensors 23FL to 23RR, and the own vehicle state detection means 33 in FIG. 2 constitute the own vehicle motion state detection means. The main control unit 6 in FIG. 1, the avoidance target point calculation means 36, the target value point arrival time calculation means 37, the vehicle yaw motion control limiting means 38, and the avoidance path calculation means 39 in FIG. 2 constitute an avoidance path information calculation means. The steering unit 3, the main control unit 6, the steering control unit 15, and the actuator control means 40 in FIG. 2 constitute vehicle behavior control means. The main control unit 6 in FIG. 1 and the avoidance margin area calculating means 35 in FIG. 2 constitute a travel enable determination means and a control execution prohibition means.

(Effect of this embodiment)
(1) When the own vehicle and the obstacle start to overlap in the vehicle width direction, the avoidance route information calculation means calculates information on the avoidance route so that the yaw rate of the own vehicle is in a direction away from the obstacle. . Then, the vehicle behavior control means controls the behavior of the host vehicle so that the host vehicle travels along the avoidance route based on the calculated avoidance route information.
For this reason, when the own vehicle begins to overlap the obstacle in the vehicle width direction, the own vehicle can be turned in a direction away from the obstacle. As a result, it is possible to prevent the driver from feeling that the host vehicle is heading toward the obstacle.
As a result, when the obstacle avoidance control is performed, the driver's uncomfortable feeling can be suppressed.

(2) The avoidance route information calculation means sets the target arrival point ahead of the traveling direction of the host vehicle from the position where the host vehicle and the obstacle start to overlap in the vehicle width direction.
For this reason, the host vehicle begins to overlap the obstacle in the vehicle width direction during the control for avoiding contact with the obstacle. Thereby, when the own vehicle starts to overlap the obstacle in the vehicle width direction, the own vehicle can be turned in a direction away from the obstacle.
In addition, after the host vehicle overlaps the obstacle in the vehicle width direction, the host vehicle can be turned in a direction suitable for the target destination point until the host vehicle reaches the target destination point.

(3) The travelability determination means determines whether there is an area where the host vehicle can travel on the side of the obstacle. When the control execution prohibiting unit determines that there is no region where the host vehicle can travel, the control of the behavior of the host vehicle is prohibited.
For this reason, when the own vehicle cannot pass through the side of the obstacle, execution of the behavior control of the own vehicle can be prohibited.

(Modification)
(1) In the present embodiment, when the avoidance route information calculating means starts to overlap the own vehicle and the obstacle in the vehicle width direction, the yaw rate of the own vehicle is directed to move away from the obstacle. Although the example of calculating the avoidance route information is shown in FIG. 5, other configurations may be employed. For example, instead of the yaw rate of the host vehicle, the avoidance route information may be calculated so that the yaw angle of the host vehicle is in a direction in which the host vehicle moves away from the obstacle.

Specifically, the vehicle yaw motion control limiting means 38 first determines that the line segment connecting the coordinates (x1, y1) detected by the avoidance margin area calculating means 35 and the origin (0, 0) of the vehicle coordinate system is the x-axis. The angle between the two is calculated, and the calculation result is used as the yaw motion limit value. Then, the yaw angle limiting unit 42 uses the threshold a as the angle at which the yaw angle of the host vehicle SW with respect to the x axis is equal to or greater than the yaw motion limit value when the obstacle arrival time TTC has elapsed since the start of the obstacle avoidance control Set the value to be.
In this case, the yaw angle of the host vehicle SW with respect to the tangential direction of the travel path can be used instead of the yaw angle of the host vehicle SW with respect to the x-axis.

1 is a schematic configuration diagram illustrating a vehicle according to an embodiment of the present invention. 4 is a block flow diagram showing a functional configuration of a main control unit 6. FIG. It is a flowchart of the arithmetic processing which confirms the driving | running | working possibility of the own vehicle. It is explanatory drawing for demonstrating the confirmation method of the driving | running | working possibility of the own vehicle. It is a flowchart of the arithmetic processing which calculates the avoidance target point coordinate Mp. It is explanatory drawing for demonstrating the calculation method of the avoidance target point coordinate Mp. It is explanatory drawing for demonstrating the calculation method of a target steering angle pattern. It is explanatory drawing for demonstrating a target steering angle pattern. It is a flowchart of the arithmetic processing which correct | amends a target steering angle pattern. It is explanatory drawing for demonstrating the correction method of a target steering angle pattern. It is explanatory drawing for demonstrating the modification of the correction method of a target steering angle pattern. It is explanatory drawing for demonstrating the extraction method of the time series data of a target steering angle. It is explanatory drawing for demonstrating a comparative example.

Explanation of symbols

3 is a steering unit (vehicle behavior control means), 4 is an external environment detection unit (travel road area detection means, obstacle position detection means), 6 is a main control unit (travel road area detection means, obstacle position detection means, self Vehicle motion state detection means, avoidance route information calculation means, vehicle behavior control means, travel capability determination means), 15 a steering control unit (vehicle behavior control means), 16 laser radar (travel road area detection means, obstacle position detection) Means), 17 is a CCD camera (running road area detecting means, obstacle position detecting means), 23FL to 23RR are wheel speed sensors (own vehicle motion state detecting means), and 30 is an external environment detecting means (running road area detecting means, Obstacle position detection means), 33 is an obstacle arrival time calculation means (own vehicle motion state detection means), 35 is an avoidance margin area calculation means (running possibility determination means, control execution prohibition means), 36 is an avoidance target point calculation means (avoidance path information calculation means), 37 is a target point arrival time calculation means (avoidance path information calculation means), 38 is a vehicle yaw motion control restriction means (avoidance path information calculation means), and 39 is avoidance. Route calculation means (avoidance route information calculation means), 40 is an actuator control means (vehicle behavior control means), and Vc is the vehicle speed (the movement state of the vehicle).

Claims (1)

A travel path region detecting means for detecting the front of the road area of the vehicle,
And obstacle position detection means for detecting the position of the obstacle in front of the vehicle,
Own vehicle movement state detection means for detecting the movement state of the own vehicle;
Based on the travel path area detected by the travel path area detection means , the position of the obstacle detected by the obstacle position detection means , and the motion state of the host vehicle detected by the host vehicle motion state detection means , The target arrival point set in front of the traveling direction of the host vehicle from the position where the host vehicle can travel while avoiding contact with the obstacle and where the host vehicle and the obstacle start to overlap in the vehicle width direction. Avoidance route information calculating means for calculating information of the avoidance route representing the route up to,
Vehicle behavior control means for controlling the behavior of the host vehicle so that the host vehicle travels along the avoidance route based on the avoidance route information calculated by the avoidance route information calculation means ;
Based on the travel path area detected by the travel path area detection means, the position of the obstacle detected by the obstacle position detection means, and the motion state of the host vehicle detected by the host vehicle motion state detection means, A travelable region determination means for determining whether or not there is a region where the host vehicle can travel on the side of an obstacle;
Control execution prohibiting means for prohibiting execution of behavior control of the own vehicle when the travelable area determining means determines that there is no area in which the own vehicle can travel on the side of the obstacle; ,
The avoidance route information calculation means is configured to determine whether the own vehicle is the obstacle based on the position of the obstacle detected by the obstacle position detection means and the movement state of the own vehicle detected by the own vehicle movement state detection means. After steering the steering wheel in a direction away from the steering wheel, a steering angle of the steering wheel exceeds a neutral position, and a target steering angle pattern for steering the steering wheel in a direction in which the host vehicle approaches the obstacle is calculated. Until the vehicle starts to overlap the obstacle in the vehicle width direction with respect to the calculated target steering angle pattern, the steering angle of the steering wheel exceeds the neutral position and the vehicle approaches the obstacle. performs correction to prohibit steering direction, the corrected the target steering angle pattern by the information of the avoidance path, wherein When the vehicle starts overlapping with the obstacle and the vehicle width direction, wherein at least one of the yaw rate of the yaw angle and the vehicle of the vehicle, and wherein the orientation and be Rukoto which the own vehicle is away from the obstacle A vehicle travel support device.

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