JP6647681B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control device, and more particularly to a vehicle control device suitable for avoiding danger during traveling.

  Technology to select either braking avoidance (brake operation only) or steering avoidance (only steering operation) according to the vehicle speed at the time of emergency avoidance of an obstacle, and calculate the target traveling route using optimization processing Has been proposed (for example, see Patent Document 1). In this technique, when the braking avoidance is selected, the calculation condition is simplified to only the movement in the vertical direction (vehicle longitudinal direction). When the steering avoidance is selected, the calculation condition is simplified only for the movement in the lateral direction (the vehicle width direction). As described above, in this technique, the calculation load is reduced in an emergency, so that the calculation time can be shortened while ensuring high calculation accuracy.

JP 2010-155545 A

  In a vehicle in which the automatic collision prevention control is executed, an automatic brake is automatically activated after a warning to a driver. However, even though the vehicle is traveling along the target traveling route that can avoid obstacles, the automatic collision prevention control may determine that the possibility of a collision is high. Alarm is generated.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a vehicle control device capable of generating an alarm at an appropriate time.

In order to achieve the above object, the present invention relates to a vehicle control device, which includes a traveling route control unit that repeatedly updates a target traveling route of a vehicle, and a collision that generates an alarm to avoid a collision with an obstacle. And a travel route control unit, wherein, when an obstacle is detected, the travel route control unit executes a travel route correction process of calculating a target travel route so as to avoid the obstacle. In the travel route correction process, at least from the obstacle to the vehicle, a speed distribution area that defines the distribution of the allowable upper limit value of the relative speed of the vehicle to the obstacle is set, and the allowable upper limit value in this speed distribution area is The target travel route is corrected so that the relative speed of the vehicle with respect to the obstacle does not exceed the allowable upper limit in the speed distribution area. A plurality of corrected travel routes for the vehicle to travel are calculated, the plurality of corrected travel routes corrected for these target travel routes are evaluated by a predetermined evaluation function, and one corrected travel route is determined according to the evaluation. The collision prevention control unit executes a collision prevention control process independently of the traveling route control unit, and in the collision prevention control process , the collision prevention control unit determines a current traveling behavior of the vehicle. Calculating a predicted travel route based on the estimated travel route, calculating a margin time for collision with an obstacle existing on the predicted travel route, and generating an alarm when the margin time reaches a predetermined time. The control unit changes an alarm generation time according to a difference between the target travel route and the predicted travel route, and the collision prevention control unit delays the alarm generation time when the difference is less than a predetermined first threshold. .

According to the present invention thus configured, when an obstacle (preceding vehicle) is detected, the traveling route control unit calculates the target traveling route so as to avoid the obstacle, and the collision prevention control unit Based on the predicted traveling route, a warning is issued when the collision margin time reaches a predetermined time. Even if the vehicle is traveling on the target traveling route so as not to collide with the obstacle, the collision prevention control unit may determine that the vehicle collides with the obstacle after the collision allowance time TTC based on the predicted traveling route. . In this case, an alarm is generated when the TTC reaches a predetermined time even though the vehicle does not actually collide with an obstacle. Therefore, in the present invention, the collision prevention control unit is configured to change the alarm generation timing to an appropriate timing according to the difference between the target travel route and the predicted travel route.
Further, according to the present invention, the collision prevention control unit delays the generation time of the alarm when the difference is smaller than the first threshold value, so that when the possibility of collision with the obstacle is low, an unnecessary alarm is generated. Can be suppressed.

  Further, in the present invention, preferably, the collision prevention control unit advances the warning generation timing when the difference exceeds the second threshold. According to the present invention configured as described above, when the possibility of collision with an obstacle is high, it is possible to generate an alarm at an early stage and to reliably avoid the collision.

  Further, specifically, in the present invention, the difference is a distance between a target position of the vehicle at a predetermined time ahead on the target travel route and a predicted position of the vehicle at a predetermined time ahead on the predicted travel route.

  According to the present invention, it is possible to provide a vehicle control device capable of generating an alarm at an appropriate time.

It is a lineblock diagram of a vehicle control system in an embodiment of the present invention. It is a control block diagram of a vehicle control system in an embodiment of the present invention. FIG. 3 is an explanatory diagram of a first traveling route according to the embodiment of the present invention. It is an explanatory view of the 2nd run course in an embodiment of the present invention. It is explanatory drawing of the 3rd driving | running route in embodiment of this invention. It is an explanatory view of obstacle avoidance control in an embodiment of the present invention. FIG. 4 is an explanatory diagram illustrating a relationship between an allowable upper limit value of a passing speed between an obstacle and a vehicle and a clearance in the obstacle avoidance control according to the embodiment of the present invention. FIG. 4 is an explanatory diagram of a traveling route correction process according to the embodiment of the present invention. It is an explanatory view of a vehicle model of an embodiment of the present invention. It is a processing flow of driving support control in an embodiment of the present invention. It is a processing flow of a run route calculation processing in an embodiment of the present invention. 4 is a processing flow of a traveling route correction process according to the embodiment of the present invention. It is a processing flow of automatic collision prevention control processing in an embodiment of the present invention. 5 is a process flow of a system control process according to the embodiment of the present invention. FIG. 9 is an explanatory diagram of an alarm occurrence timing change process according to the embodiment of the present invention. It is a processing flow of alarm occurrence time change processing in an embodiment of the present invention.

  Hereinafter, a vehicle control system according to an embodiment of the present invention will be described with reference to the accompanying drawings. First, the configuration of the vehicle control system will be described with reference to FIGS. FIG. 1 is a configuration diagram of a vehicle control system, and FIG. 2 is a control block diagram of the vehicle control system.

  The vehicle control system 100 of the present embodiment is configured to provide different driving support control to the vehicle 1 (see FIG. 3 and the like) in a plurality of driving support modes. The driver can select a desired driving support mode from a plurality of driving support modes.

  As shown in FIG. 1, a vehicle control system 100 is mounted on a vehicle 1, and has a vehicle control device (ECU) 10, a plurality of sensors and switches, a plurality of control systems, and user inputs for a driving support mode. Is provided with a driver operation unit 35 for performing the operation. The plurality of sensors and switches include an on-board camera 21, a millimeter wave radar 22, a plurality of behavior sensors (vehicle speed sensor 23, acceleration sensor 24, yaw rate sensor 25) for detecting the behavior of the vehicle, and a plurality of behavior switches (steering angle sensor 26). , Accelerator sensor 27, brake sensor 28), positioning system 29, and navigation system 30. The plurality of control systems include an engine control system 31, a brake control system 32, and a steering control system 33.

  The driver operation unit 35 is provided in the passenger compartment of the vehicle 1 so as to be operable by the driver, and includes a mode selection switch 36 for selecting a desired driving support mode from a plurality of driving support modes. A set vehicle speed input unit 37 for inputting a set vehicle speed in accordance with the driving assistance mode. When the driver operates the mode selection switch 36, a driving support mode selection signal corresponding to the selected driving support mode is output. When the driver operates the set vehicle speed input unit 37, a set vehicle speed signal is output.

  The ECU 10 is configured by a computer including a CPU, a memory for storing various programs, an input / output device, and the like. The ECU 10 provides the engine control system 31, the brake control system 32, and the steering control system 33 based on the driving support mode selection signal and the set vehicle speed signal received from the driver operation unit 35 and the signals received from the plurality of sensors and switches. On the other hand, a request signal for appropriately operating the engine system, the brake system, and the steering system can be output.

  The on-vehicle camera 21 captures an image of the periphery of the vehicle 1 and outputs data of the captured image. The ECU 10 specifies an object (for example, a vehicle, a pedestrian, a road, a lane marking (lane boundary line, white line, yellow line), a traffic signal, a traffic sign, a stop line, an intersection, an obstacle, etc.) based on the image data. I do. Note that the ECU 10 may acquire information on the target from outside via a vehicle-mounted communication device, such as through a traffic infrastructure or vehicle-to-vehicle communication.

  The millimeter wave radar 22 is a measuring device that measures the position and speed of an object (particularly, a preceding vehicle, a parked vehicle, a pedestrian, an obstacle, and the like), and transmits a radio wave (transmitted wave) toward the front of the vehicle 1. Then, the reflected wave generated by reflecting the transmitted wave by the object is received. Then, the millimeter-wave radar 22 measures the distance between the vehicle 1 and the target (for example, the inter-vehicle distance) and the relative speed of the target with respect to the vehicle 1 based on the transmission wave and the reception wave. In the present embodiment, a configuration may be adopted in which the distance and the relative speed to the object are measured using a laser radar, an ultrasonic sensor, or the like instead of the millimeter wave radar 22. Further, the position and speed measurement device may be configured using a plurality of sensors.

The vehicle speed sensor 23 detects the absolute speed of the vehicle 1.
The acceleration sensor 24 detects the acceleration of the vehicle 1 (vertical acceleration in the front-rear direction, lateral acceleration in the horizontal direction). The acceleration includes a speed increasing side (positive) and a decelerating side (negative).
Yaw rate sensor 25 detects a yaw rate of vehicle 1.
The steering angle sensor 26 detects a rotation angle (steering angle) of a steering wheel of the vehicle 1.
The accelerator sensor 27 detects the amount of depression of the accelerator pedal.
The brake sensor 28 detects the amount of depression of the brake pedal.

The positioning system 29 is a GPS system and / or a gyro system, and detects the position of the vehicle 1 (current vehicle position information).
The navigation system 30 stores map information inside, and can provide the map information to the ECU 10. The ECU 10 specifies a road, an intersection, a traffic signal, a building, and the like existing around the vehicle 1 (particularly ahead of the traveling direction) based on the map information and the current vehicle position information. The map information may be stored in the ECU 10.

  The engine control system 31 is a controller that controls the engine of the vehicle 1. When it is necessary to accelerate or decelerate the vehicle 1, the ECU 10 outputs an engine output change request signal requesting a change in engine output to the engine control system 31.

  The brake control system 32 is a controller for controlling the brake device of the vehicle 1. When it is necessary to decelerate the vehicle 1, the ECU 10 outputs a brake request signal requesting the brake control system 32 to generate a braking force on the vehicle 1.

  The steering control system 33 is a controller that controls a steering device of the vehicle 1. When it is necessary to change the traveling direction of the vehicle 1, the ECU 10 outputs a steering direction change request signal requesting the steering control system 33 to change the steering direction.

  As shown in FIG. 2, the ECU 10 includes a single CPU that functions as a traveling route control unit 10a, an automatic collision prevention control unit 10b, an input processing unit 10c, and an output control unit 10d. The input processing unit 10c processes input information received from the plurality of sensors / switches and the driver operation unit 35. The traveling route control unit 10a and the automatic collision prevention control unit 10b execute arithmetic processing using the processed input information. In the present embodiment, the automatic collision prevention control, which is the automatic emergency avoidance control with high urgency, is configured to be executed independently of the normal traveling route control. In the present embodiment, a single CPU is configured to execute a plurality of the above functions. However, the present invention is not limited to this, and another CPU may be configured to execute each function.

  In the present embodiment, the automatic emergency avoidance control sends a request signal to at least one or more of the engine control system 31, the brake control system 32, and the steering control system 33 in order to change the behavior of the vehicle 1 in an emergency. This is the control to be generated.

  The travel route control unit 10a calculates a target travel route based on the input information, and performs a first control for the engine control system 31, the brake control system 32, and the steering control system 33 so that the vehicle 1 travels on the target travel route. Generates a request signal. The automatic collision prevention control unit 10b generates a second request signal to the brake control system 32 based on the input information so as to operate the emergency automatic brake for avoiding a collision with an obstacle. The output control unit 10d selectively outputs the request signal received from the control units 10a and 10b to the engine control system 31, the brake control system 32, and the steering control system 33.

  Next, the driving support mode provided in the vehicle control system 100 according to the present embodiment will be described. In the present embodiment, four modes (preceding vehicle following mode, automatic speed control mode, speed limit mode, and basic control mode) are provided as the driving support modes.

<Preceding vehicle following mode>
The preceding vehicle following mode is a mode in which the vehicle 1 follows the preceding vehicle while maintaining a predetermined inter-vehicle distance corresponding to the vehicle speed between the vehicle 1 and the preceding vehicle. It involves automatic steering control, speed control (engine control, brake control), and obstacle avoidance control (speed control and steering control).

  In the preceding vehicle following mode, different steering control and speed control are performed depending on whether or not detection of both ends of the lane is possible and whether or not there is a preceding vehicle. Here, both ends of the lane are both ends of the lane in which the vehicle 1 travels (compartment lines such as white lines, road edges, curbs, median strips, guardrails, etc.), and are boundaries between adjacent lanes and sidewalks. is there. The ECU 10 serving as the traveling road edge detection unit detects the two ends of the lane from the image data captured by the vehicle-mounted camera 21. Alternatively, both end portions of the lane may be detected from the map information of the navigation system 30. However, for example, when the vehicle 1 is traveling on a plain where there is no lane, not on a well-maintained road, or when the image data from the in-vehicle camera 21 is poorly read, the lane ends may not be detected.

  In the above-described embodiment, the ECU 10 is used as the traveling road edge detection unit. However, the present invention is not limited to this. The vehicle-mounted camera 21 as the traveling road edge detection unit may detect both ends of the lane. The in-vehicle camera 21 serving as the unit detection unit and the ECU 10 may cooperate to detect both ends of the lane.

  Further, in the present embodiment, the ECU 10 as the preceding vehicle detecting unit detects the preceding vehicle based on the image data from the onboard camera 21 and the measurement data from the millimeter wave radar 22. Specifically, another vehicle traveling ahead is detected as a traveling vehicle based on the image data from the vehicle-mounted camera 21. Further, in the present embodiment, when the inter-vehicle distance between the vehicle 1 and another vehicle is equal to or less than a predetermined distance (for example, 400 to 500 m), the other vehicle is detected as a preceding vehicle based on the measurement data obtained by the millimeter wave radar 22. You.

  In the above-described embodiment, the ECU 10 is used as the preceding vehicle detecting unit. However, the present invention is not limited to this. The on-board camera 21 as the preceding vehicle detecting unit may detect other vehicles traveling ahead. The camera 21 and the millimeter wave radar 22 may constitute a part of the preceding vehicle detection unit.

(Preceding vehicle following mode: lane detection possible)
First, when both ends of the lane are detected, the vehicle 1 is controlled so as to run near the center of the lane, and is set in advance by the driver using the set vehicle speed input unit 37 or by the system 100 based on predetermined processing. Speed control is performed so as to maintain the set vehicle speed (constant speed). If the set vehicle speed is higher than the limit vehicle speed (the speed limit specified in accordance with the speed sign or the curvature of the curve), the speed limit is prioritized, and the vehicle speed of the vehicle 1 is limited to the speed limit. The speed limit defined in accordance with the curvature of the curve is calculated by a predetermined formula, and is set to a lower speed as the curvature of the curve is larger (the radius of curvature is smaller).

  When the set vehicle speed of the vehicle 1 is higher than the vehicle speed of the preceding vehicle, the speed of the vehicle 1 is controlled so as to follow the preceding vehicle while maintaining the inter-vehicle distance according to the vehicle speed. Further, when the preceding vehicle following the vehicle 1 does not exist in front of the vehicle 1 due to a lane change or the like, the speed of the vehicle 1 is controlled again so as to maintain the set vehicle speed.

(Preceding vehicle following mode: lane detection not possible, preceding vehicle present)
Also, when both ends of the lane are not detected, and when a preceding vehicle is present, the vehicle 1 is subjected to steering control so as to follow the traveling trajectory of the preceding vehicle, and has a speed on the traveling trajectory of the preceding vehicle. Is controlled to follow the speed.

(Preceding vehicle following mode: no lane detection, no preceding vehicle)
In addition, when both ends of the lane are not detected and there is no preceding vehicle, the traveling position on the traveling path cannot be specified (the lane marking cannot be detected, and the preceding vehicle cannot be followed). In this case, the driver operates the steering wheel, the accelerator pedal, and the brake pedal to maintain or change the current running behavior (steering angle, yaw rate, vehicle speed, acceleration, and the like) according to the driver's intention. And speed control.

  In the preceding vehicle following mode, obstacle avoidance control (speed control and steering control), which will be described later, is further automatically executed irrespective of the presence or absence of the preceding vehicle and whether or not detection of both ends of the lane is possible.

<Automatic speed control mode>
The automatic speed control mode is a mode in which speed control is performed so as to maintain a predetermined vehicle speed (constant speed) preset by the driver or by the system 100, and automatic speed control by the vehicle control system 100 ( Although engine control and brake control) and obstacle avoidance control (speed control) are involved, steering control is not performed. In this automatic speed control mode, the vehicle 1 travels so as to maintain the set vehicle speed, but the speed can be increased beyond the set vehicle speed by the driver depressing the accelerator pedal. When the driver performs the brake operation, the driver's intention is given priority and the vehicle is decelerated from the set vehicle speed. When the vehicle catches up with the preceding vehicle, the speed is controlled so as to follow the preceding vehicle while maintaining the inter-vehicle distance according to the vehicle speed. Is done.

<Speed limit mode>
The speed limit mode is a mode in which the speed of the vehicle 1 is controlled so that the vehicle speed does not exceed the speed limit set by the speed sign or the speed set by the driver. Engine control). The speed limit may be specified by the image recognition processing performed by the ECU 10 on image data of the speed sign or the speed display on the road surface captured by the vehicle-mounted camera 21 or may be received by external wireless communication. In the speed limit mode, even if the driver depresses the accelerator pedal so as to exceed the speed limit, the speed of the vehicle 1 is increased only to the speed limit.

<Basic control mode>
The basic control mode is a mode (off mode) when the driving operation mode is not selected by the driver operation unit 35, and the automatic steering control and the speed control by the vehicle control system 100 are not performed. However, the automatic collision prevention control is configured to be executed. In this control, when the vehicle 1 may collide with a preceding vehicle or the like, the brake control is automatically executed to avoid the collision. You. The automatic collision prevention control is similarly executed in the preceding vehicle following mode, the automatic speed control, and the speed limit mode.

  Also, in the automatic speed control mode, the speed limit mode, and the basic control mode, obstacle avoidance control (only speed control or speed control and steering control) to be described later is further executed.

  Next, a plurality of traveling routes calculated in the vehicle control system 100 according to the present embodiment will be described with reference to FIGS. 3 to 5 are explanatory diagrams of a first traveling route to a third traveling route, respectively. In the present embodiment, the ECU 10 is configured to temporally and repeatedly calculate the following first travel route R1 to third travel route R3 (for example, every 0.1 second). In the present embodiment, the ECU 10 calculates a traveling route from the present time to a predetermined period (for example, 3 seconds) from the present time based on information from a sensor or the like. The travel route Rx (x = 1, 2, 3) is specified by the target position (Px_k) and the target speed (Vx_k) of the vehicle 1 on the travel route (k = 0, 1, 2,..., N). ). Further, at each target position, a target value is specified for a plurality of variables (acceleration, acceleration change amount, yaw rate, steering angle, vehicle angle, etc.) other than the target speed.

  Note that the traveling routes (first traveling route to third traveling route) in FIGS. 3 to 5 are obstacles related to obstacles (including parked vehicles, pedestrians, and the like) on or around the traveling route on which the vehicle 1 travels. The calculation is performed based on the shape of the traveling road, the traveling locus of the preceding vehicle, the traveling behavior of the vehicle 1, and the set vehicle speed without considering the information. As described above, in the present embodiment, since the obstacle information is not considered in the calculation, the overall calculation load of the plurality of traveling routes can be reduced.

In the following, for ease of understanding, each traveling route calculated when the vehicle 1 travels on the road 5 including the straight section 5a, the curved section 5b, and the straight section 5c will be described. Road 5 consists of the left and right lane 5 _L, 5 _R. At present, the vehicle 1 is assumed to be traveling on the lane 5 _L of the straight sections 5a.

(First traveling route)
As shown in FIG. 3, the first travel route R1 is set for a predetermined period as in line with the shape of the road 5 to maintain the travel lane 5 in _L is traveling path of the vehicle 1. Specifically, the first traveling route R1 is straight section 5a, the vehicle 1, 5c is set to maintain a running near the center of the lane 5 _L, the vehicle 1 in the curve section 5b is higher than the center in the width direction of the lane 5 _L Is also set to run on the inside or in side (the center O side of the curvature radius L of the curve section).

The ECU 10 performs image recognition processing of image data around the vehicle 1 captured by the on-board camera 21 and detects both end portions 6 _L and 6 _R of the lane. As described above, the lane ends are lane markings (white lines and the like) and road shoulders. Furthermore, ECU 10 based on the detected lane end portions 6 _L, 6 _R, calculates the radius of curvature L of the lane width W, and the curve section 5b lane 5 _L. Alternatively, the lane width W and the radius of curvature L may be obtained from the map information of the navigation system 30. Further, the ECU 10 reads the speed sign S and the speed limit displayed on the road from the image data. Note that, as described above, the speed limit may be obtained by external wireless communication.

ECU10 is straight section 5a, the 5c, a width direction central portion of the center in the width direction of the lane end portions 6 _L, 6 _R vehicle 1 (e.g., center of gravity position) so as to pass through the first traveling route R1 A plurality of target positions P1_k are set.

Meanwhile, ECU 10 is in the curve section 5b, in the longitudinal direction of the center position P1_c curve section 5b, sets the widthwise center position of the lane 5 _L maximum displacement amount Ws to the in-side. The displacement Ws is calculated based on the radius of curvature L, the lane width W, and the width dimension D of the vehicle 1 (a specified value stored in the memory of the ECU 10). Then, the ECU 10 sets a plurality of target positions P1_k of the first traveling route R1 so as to smoothly connect the center position P1_c of the curve section 5b and the center position in the width direction of the straight sections 5a and 5c. Note that the first travel route R1 may be set on the in side of the straight sections 5a and 5c before and after entering the curved section 5b.

  The target speed V1_k at each target position P1_k of the first travel route R1 is basically determined by the driver at a predetermined set vehicle speed (constant speed) preset by the set vehicle speed input unit 37 of the driver operation unit 35 or by the system 100. ). However, when the set vehicle speed exceeds the speed limit obtained from the speed sign S or the like or the speed limit defined in accordance with the radius of curvature L of the curve section 5b, the target speed of each target position P1_k on the traveling route is determined. V1_k is limited to a lower speed limit among the two speed limits. Further, the ECU 10 appropriately corrects the target position P1_k and the target vehicle speed V1_k according to the current behavior state of the vehicle 1 (that is, vehicle speed, acceleration, yaw rate, steering angle, lateral acceleration, etc.). For example, if the current vehicle speed is significantly different from the set vehicle speed, the target vehicle speed is corrected so that the vehicle speed approaches the set vehicle speed.

(2nd travel route)
Further, as shown in FIG. 4, the second traveling route R2 is set for a predetermined period so as to follow the traveling locus of the preceding vehicle 3. ECU10, the image data by the in-vehicle camera 21, measured by the millimeter wave radar 22 data, based on the vehicle speed of the vehicle 1 by the vehicle speed sensor 23, continuous position and velocity of the preceding vehicle 3 on lanes 5 _L of travel of the vehicle 1 These are stored as the preceding vehicle locus information, and the traveling locus of the preceding vehicle 3 is set as the second traveling route R2 (target position P2_k, target speed V2_k) based on the preceding vehicle locus information.

(3rd travel route)
Further, as shown in FIG. 5, the third traveling route R3 is set for a predetermined period based on the current driving state of the vehicle 1 by the driver. That is, the third traveling route R3 is set based on the position and the speed estimated from the current traveling behavior of the vehicle 1.

  The ECU 10 calculates a target position P3_k of the third traveling route R3 for a predetermined period based on the steering angle, the yaw rate, and the lateral acceleration of the vehicle 1. However, when both ends of the lane are detected, the ECU 10 corrects the target position P3_k so that the calculated third traveling route R3 does not approach or cross the lane end.

  Further, the ECU 10 calculates a target speed V3_k of the third traveling route R3 for a predetermined period based on the current vehicle speed and acceleration of the vehicle 1. When the target speed V3_k exceeds the speed limit obtained from the speed sign S or the like, the target speed V3_k may be corrected so as not to exceed the speed limit.

  Next, the relationship between the driving support mode and the traveling route in the vehicle control system 100 according to the present embodiment will be described. In the present embodiment, when the driver operates the mode selection switch 36 to select one driving support mode, the ECU 10 selects one of the first travel route R1 to the third travel route R3 according to measurement data obtained by a sensor or the like. , One of which is selected.

  When the preceding vehicle following mode is selected, if both ends of the lane are detected, the first traveling route is applied regardless of the presence or absence of the preceding vehicle. In this case, the set vehicle speed set by the set vehicle speed input unit 37 becomes the target speed.

  On the other hand, when the preceding vehicle following mode is selected, when both ends of the lane are not detected and the preceding vehicle is detected, the second traveling route is applied. In this case, the target speed is set according to the speed of the preceding vehicle. In addition, when the preceding vehicle following mode is selected, if both ends of the lane are not detected and no preceding vehicle is detected, the third travel route is applied.

  When the automatic speed control mode is selected, the third traveling route is applied. The automatic speed control mode is a mode in which the speed control is automatically executed as described above, and the set vehicle speed set by the set vehicle speed input unit 37 becomes the target speed. Further, steering control is executed based on the operation of the steering wheel by the driver.

  The third travel route is also applied when the speed limit mode is selected. The speed limit mode is also a mode in which speed control is automatically executed as described above, and the target speed is set in a range equal to or less than the speed limit according to the amount of depression of the accelerator pedal by the driver. Further, steering control is executed based on the operation of the steering wheel by the driver.

  When the basic control mode (off mode) is selected, the third travel route is applied. The basic control mode is basically the same as the state in which the speed limit is not set in the speed limit mode.

Next, with reference to FIGS. 6 to 9, a description will be given of the obstacle avoidance control executed in the vehicle control system 100 according to the present embodiment and the accompanying traveling route correction processing. 6 is an explanatory diagram of the obstacle avoidance control, FIG. 7 is an explanatory diagram showing a relationship between an allowable upper limit value of a passing speed between the obstacle and the vehicle and a clearance in the obstacle avoidance control, and FIG. 8 is a traveling route correction process. FIG. 9 is an explanatory diagram of a vehicle model.
In FIG. 6, the vehicle 1 is traveling on a traveling path (lane) 7, and is trying to pass the vehicle 3 by passing the traveling or stopped vehicle 3.

  Generally, when passing (or overtaking) an obstacle on the road or near the road (for example, a preceding vehicle, a parked vehicle, a pedestrian, etc.), the driver of the vehicle 1 moves in a lateral direction orthogonal to the traveling direction. A predetermined clearance or interval (lateral distance) is maintained between the vehicle 1 and the obstacle, and the speed is reduced to a speed at which the driver of the vehicle 1 feels safe. Specifically, in order to avoid the danger of the preceding vehicle suddenly changing course, pedestrians coming out of the blind spot of an obstacle, or opening the door of a parked vehicle, the smaller the clearance, the smaller the obstacle The relative speed is reduced.

  Generally, when approaching the preceding vehicle from behind, the driver of the vehicle 1 adjusts the speed (relative speed) according to the inter-vehicle distance (vertical distance) along the traveling direction. Specifically, when the inter-vehicle distance is large, the approach speed (relative speed) is maintained high, but when the inter-vehicle distance is reduced, the approach speed is reduced. Then, the relative speed between the two vehicles becomes zero at a predetermined inter-vehicle distance. This is the same even if the preceding vehicle is a parked vehicle.

  As described above, the driver drives the vehicle 1 so as to avoid danger while considering the relationship between the distance (including the horizontal distance and the vertical distance) between the obstacle and the vehicle 1 and the relative speed. are doing.

Therefore, in the present embodiment, as shown in FIG. 6, the vehicle 1 moves around the obstacle (for example, the parked vehicle 3) around the obstacle (the lateral area, the rear area, And over the front area) or at least between the obstacle and the vehicle 1, a two-dimensional distribution (speed distribution area 40) that defines an allowable upper limit value for the relative speed in the traveling direction of the vehicle 1 is set. I have. In the speed distribution area 40, an allowable upper limit value _Vlim of the relative speed is set at each point around the obstacle. In the present embodiment, in all the driving support modes, the obstacle avoidance control for preventing the relative speed of the vehicle 1 from the obstacle from exceeding the allowable upper limit value V _lim in the speed distribution region 40 is performed.

As can be seen from FIG. 6, the speed distribution region 40 is, in principle, such that the allowable upper limit value of the relative speed decreases as the horizontal distance and the vertical distance from the obstacle decrease (closer to the obstacle). Is set. FIG. 6 shows equi-relative velocity lines connecting points having the same allowable upper limit value for easy understanding. The equal relative velocity lines a, b, c, and d correspond to the allowable upper limit values V _lim of 0 km / h, 20 km / h, 40 km / h, and 60 km / h, respectively. In this example, each equi-relative speed area is set to be substantially rectangular.

  Note that the speed distribution area 40 does not necessarily need to be set over the entire circumference of the obstacle, and at least behind the obstacle and one side in the lateral direction of the obstacle where the vehicle 1 exists (in FIG. May be set to the right side area of

As shown in FIG. 7, when the vehicle 1 runs at a certain absolute speed, the allowable upper limit value V _lim set in the lateral direction of the obstacle is 0 (zero) until the clearance X reaches D ₀ (safety distance). km / h and increases quadratically above D ₀ (V _lim = k (X−D ₀ ) ² , where X ≧ D ₀ ). That is, since the safety clearance X is the vehicle 1 is the relative speed is zero at D ₀ below. On the other hand, the clearance X is D ₀ or more, the clearance is larger, the vehicle 1 makes it possible to pass each other at a large relative speed.

In the example of FIG. 7, the allowable upper limit value of the obstacle in the horizontal direction is _defined as V _lim = f (X) = k (X−D ₀ ) ² . Note that k is a gain coefficient related to the degree of change of V _lim with respect to X, and is set depending on the type of obstacle or the like. D _{0 is} also set depending on the type of the obstacle.

In the present embodiment, V _lim is defined to be a quadratic function of X, but is not limited thereto, and may be defined by another function (for example, a linear function or the like). In addition, the allowable upper limit value V _lim of the obstacle in the horizontal direction has been described with reference to FIG. 7, but can be set similarly in all radial directions including the vertical direction of the obstacle. At that time, the coefficient k, the safety distance D ₀ may be set in accordance with the direction from the obstacle.

Note that the speed distribution area 40 can be set based on various parameters. As parameters, for example, the relative speed of the vehicle 1 and the obstacle, the type of the obstacle, the traveling direction of the vehicle 1, the moving direction and moving speed of the obstacle, the length of the obstacle, the absolute speed of the vehicle 1, and the like are taken into consideration. Can be. That is, it is possible on the basis of these parameters, to select the coefficient k and the safety distance D _0.

  In the present embodiment, the obstacle includes a vehicle, a pedestrian, a bicycle, a cliff, a groove, a hole, a falling object, and the like. Further, vehicles can be distinguished by automobiles, trucks, and motorcycles. Pedestrians can be distinguished by adults, children and groups.

  As shown in FIG. 6, when the vehicle 1 is traveling on the traveling path 7, the ECU 10 of the vehicle 1 detects an obstacle (vehicle 3) based on image data from the onboard camera 21. At this time, the type of the obstacle (in this case, a vehicle or a pedestrian) is specified.

  Further, the ECU 10 calculates the position, relative speed and absolute speed of the obstacle (vehicle 3) with respect to the vehicle 1 based on the measurement data of the millimeter wave radar 22 and the vehicle speed data of the vehicle speed sensor 23. The position of the obstacle includes an x-direction position (longitudinal distance) along the traveling direction of the vehicle 1 and a y-direction position (lateral distance) along a lateral direction orthogonal to the traveling direction.

The ECU 10 sets the speed distribution area 40 for all the detected obstacles (the vehicle 3 in FIG. 6). Then, the ECU 10 performs the obstacle avoidance control so that the speed of the vehicle 1 does not exceed the allowable upper limit value V _lim of the speed distribution area 40. For this reason, the ECU 10 corrects the target traveling route applied according to the driving support mode selected by the driver in accordance with the obstacle avoidance control.

  That is, when the vehicle 1 travels on the target traveling route, if the target speed exceeds the allowable upper limit value defined by the speed distribution area 40 at a certain target position, the target speed is reduced without changing the target position. Either (route Rc1 in FIG. 6), the target position is changed on the detour route so that the target speed does not exceed the allowable upper limit without changing the target speed (route Rc3 in FIG. 6), the target position and the target speed. Are changed (route Rc2 in FIG. 6).

For example, FIG. 6 illustrates a case where the calculated target travel route R is a route that travels at a center position (target position) in the width direction of the travel path 7 at a speed of 60 km / h (target speed). In this case, the parked vehicle 3 is present as an obstacle in front, but as described above, this obstacle is not considered in the calculation stage of the target travel route R in order to reduce the calculation load.

When traveling on the target traveling route R, the vehicle 1 sequentially crosses the equi-relative velocity lines d, c, c, and d in the velocity distribution area 40. That is, the vehicle 1 traveling at 60 km / h enters the area inside the equi-relative speed line d (allowable upper limit value V _lim = 60 km / h). Therefore, the ECU 10 corrects the target travel route R so as to limit the target speed at each target position on the target travel route R to the allowable upper limit value _Vlim or less, and generates the corrected target travel route Rc1. That is, in the corrected target traveling route Rc1, the target speed gradually decreases to less than 40 km / h as approaching the vehicle 3 so that the target vehicle speed becomes equal to or lower than the allowable upper limit value V _{lim at} each target position. Thereafter, as the vehicle 3 moves away from the vehicle 3, the target speed is gradually increased to the original speed of 60 km / h.

  The target traveling route Rc3 is set so as to travel outside the constant relative speed line d (corresponding to the relative speed of 60 km / h) without changing the target speed (60 km / h) of the target traveling route R. Route. In order to maintain the target speed of the target travel route R, the ECU 10 corrects the target travel route R so as to change the target position so that the target position is on or outside the equi-relative speed line d, and performs the target travel. A route Rc3 is generated. Therefore, the target speed of the target travel route Rc3 is maintained at 60 km / h, which is the target speed of the target travel route R.

  The target travel route Rc2 is a route in which both the target position and the target speed of the target travel route R have been changed. In the target traveling route Rc2, the target speed is not maintained at 60 km / h, but gradually decreases as approaching the vehicle 3 and thereafter gradually increases to the original 60 km / h as moving away from the vehicle 3. Is done.

  The correction for changing only the target speed without changing the target position of the target travel route R like the target travel route Rc1 can be applied to a driving support mode that involves speed control but does not involve steering control ( For example, an automatic speed control mode, a speed limit mode, and a basic control mode).

  Further, the correction for changing only the target position without changing the target speed of the target travel route R as in the case of the target travel route Rc3 can be applied to a driving support mode involving steering control (for example, following a preceding vehicle). mode).

  Further, like the target travel route Rc2, the correction for changing both the target position and the target speed of the target travel route R can be applied to a driving support mode involving speed control and steering control (for example, a preceding vehicle following mode). ).

  Next, as shown in FIG. 8, the ECU 10 (the traveling route control unit 10a) calculates the target traveling route R based on the above-described sensor information and the like. Then, when an obstacle is detected, the ECU 10 calculates the corrected travel routes R1 to R3 according to the driving support mode and the like by the travel route correction process. In the present embodiment, the traveling route correction process is an optimization process using the evaluation function J.

  The ECU 10 stores an evaluation function J, a constraint condition, and a vehicle model in a memory. In the travel route correction process, the ECU 10 calculates a corrected travel route that minimizes the evaluation function J within a range that satisfies the constraint conditions and the vehicle model (optimization process).

  The evaluation function J has a plurality of evaluation factors. The evaluation factors in this example are, for example, speed (vertical and lateral directions), acceleration (vertical and lateral directions), acceleration change amount (vertical and lateral directions), yaw rate, lateral position with respect to lane center, vehicle angle, steering This is a function for evaluating the difference between the target travel route and the corrected travel route for angles and other soft constraints.

  The evaluation factors include an evaluation factor relating to the vertical behavior of the vehicle 1 (vertical evaluation factor: vertical speed, acceleration, acceleration change amount, etc.) and an evaluation factor relating to the lateral behavior of the vehicle 1 (lateral evaluation factor). : Lateral speed, acceleration, acceleration change amount, yaw rate, lateral position with respect to lane center, vehicle angle, steering angle, etc.).

Specifically, the evaluation function J is described by the following equation.

In the formula, Wk (Xk−Xrefk) ² is an evaluation factor, Xk is a physical quantity related to the evaluation factor of the corrected travel route, Xrefk is a physical quantity related to the evaluation factor of the target travel route (before correction), and Wk is a weight value of the evaluation factor (for example, 0 ≦ Wk ≦ 1) (where k = 1 to n). Therefore, the evaluation function J of the present embodiment is, for the physical quantities of the n evaluation factors, the difference between the physical quantity of the corrected travel path and the physical quantity of the target travel path (before correction) calculated assuming that no obstacle exists. The sum of the squares is weighted and corresponds to a value summed over the travel path length for a predetermined period (for example, N = 3 seconds).

  The constraint includes at least one constraint factor that restricts the behavior of the vehicle 1. Each constraint factor is directly or indirectly associated with any evaluation factor. Therefore, the behavior of the vehicle 1 (that is, the physical quantity of the evaluation factor) is restricted by the constraint condition, so that the optimization process using the evaluation function J can be converged at an early stage, and the calculation time can be reduced. Note that the constraint conditions are set differently depending on the driving support mode.

The constraint factors in this example include, for example, speed (vertical and lateral directions), acceleration (vertical and lateral directions), amount of change in acceleration (vertical and lateral directions), vehicle speed time deviation, lateral position with respect to the center position, headway It includes a distance time deviation, a steering angle, a steering angular velocity, a steering torque, a steering torque rate, a yaw rate, and a vehicle angle. An allowable numerical range is set for each of these constraint factors (for example, -5 m / s ² ≤ longitudinal acceleration ≤ 4 m / s ² , -4 m / s ² ≤ lateral acceleration ≤ 4 m / s ² ). For example, the maximum values of the vertical G and the horizontal G in the corrected traveling route can be limited by restricting the vertical and horizontal accelerations that greatly affect the riding comfort by the constraint condition.

  The vehicle model defines the physical motion of the vehicle 1, and is described by the following equation of motion. This vehicle model is a two-wheel model shown in FIG. 9 in this example. By defining the physical movement of the vehicle 1 by the vehicle model, it is possible to calculate a corrected traveling route with reduced discomfort during traveling, and to quickly converge the optimization processing by the evaluation function J. it can.

9 and wherein, m is the mass of the vehicle 1, I is yawing inertial moment of the vehicle 1, l is a wheel base, l _f is the distance between the vehicle center of gravity and a front axle, l _r is between the vehicle center of gravity and the rear axle , K _f is the tire cornering power per front wheel, K _r is the tire cornering power per rear wheel, V is the vehicle speed of vehicle 1, δ is the actual steering angle of the front wheels, and β is the side slip of the vehicle center of gravity. The angle, r is the yaw angular velocity of the vehicle 1, θ is the yaw angle of the vehicle 1, y is the lateral displacement of the vehicle 1 with respect to the absolute space, and t is the time.

  The ECU 10 calculates a corrected travel route that minimizes the evaluation function J from a number of corrected travel routes based on the target travel route, the constraint condition, the vehicle model, the obstacle information, and the like. That is, in the traveling route correction processing, the ECU 10 functions as a solver that outputs a solution to the optimization problem. Therefore, as the corrected travel route calculated as the optimal solution, the one that is closest (closest) to the target travel route before correction is selected while securing an appropriate distance and relative speed to the obstacle.

  Next, a processing flow of the driving support control in the vehicle control system 100 of the present embodiment will be described with reference to FIGS. 10 is a processing flow of driving support control, FIG. 11 is a processing flow of traveling route calculation processing, FIG. 12 is a processing flow of traveling route correction processing, FIG. 13 is a processing flow of automatic collision prevention control processing, and FIG. 14 is a system control processing. It is a processing flow of.

  The ECU 10 repeatedly executes the processing flow of FIG. 10 every predetermined time (for example, 0.1 second). First, the ECU 10 (input processing unit 10c) executes an information acquisition process (S11). In the information acquisition process, the ECU 10 acquires the current vehicle position information and the map information from the positioning system 29 and the navigation system 30 (S11a), and mounts the vehicle-mounted camera 21, the millimeter wave radar 22, the vehicle speed sensor 23, the acceleration sensor 24, and the yaw rate sensor. 25, sensor information is acquired from the driver operation unit 35 and the like (S11b), and switch information is acquired from the steering angle sensor 26, the accelerator sensor 27, the brake sensor 28, and the like (S11c).

  Next, the ECU 10 (input processing unit 10c) performs a predetermined information detection process using various types of information acquired in the information acquisition process (S11) (S12). In the information detection process, the ECU 10 uses the current vehicle position information, the map information, and the sensor information to determine the travel path information (the presence or absence of a straight section and a curve section, the length of each section, the curve, Curvature radius, lane width, lane end positions, number of lanes, presence or absence of intersection, speed limit specified by curve curvature, etc., travel regulation information (speed limit, red traffic light, etc.), preceding vehicle trajectory information (preceding vehicle) Is detected (S12a).

  Further, the ECU 10 detects vehicle operation information (steering angle, accelerator pedal depression amount, brake pedal depression amount, etc.) relating to vehicle operation by the driver from the switch information (S12b), and further detects the vehicle information from the switch information and the sensor information. The traveling behavior information (vehicle speed, longitudinal acceleration, lateral acceleration, yaw rate, etc.) relating to the behavior of No. 1 is detected (S12c).

Next, the ECU 10 (the traveling route control unit 10a) executes a traveling route control process based on the information obtained by the calculation (S13). The travel route control process includes a travel route calculation process (S13a), a travel route correction process (S13b), and a first request signal generation process (S13c).
In the travel route calculation processing (S13a), the first travel route, the second travel route, or the third travel route is calculated as described above.

  In the travel route correction process (S13b), the ECU 10 corrects the target travel route based on the obstacle information (for example, the parked vehicle 3 shown in FIG. 6). In the travel route correction process, the travel route is corrected so that the vehicle 1 avoids an obstacle by speed control and / or steering control according to the driving assistance mode selected in principle.

  In the first request signal generation process (S13c), the ECU 10 controls the corresponding control system (engine control) so that the vehicle 1 travels on the finally calculated travel route in accordance with the selected driving support mode. System 31, a brake control system 32, and a steering control system 33). Specifically, the ECU 10 responds to a first request signal (engine request signal, brake request signal, (A steering request signal).

  On the other hand, the ECU 10 (automatic collision prevention control unit 10b) executes the automatic collision prevention control process (S14) in parallel with the traveling route control process (S13), and generates a second request signal (brake request signal). .

  Further, the ECU 10 (output control unit 10d) outputs a request signal to the engine control system 31, the brake control system 32, and the steering control system 33 based on the generated first request signal or the second request signal ( System control processing; S15).

Next, a detailed processing flow of the traveling route calculation processing (S13a) of FIG. 10 will be described with reference to FIG.
First, the ECU 10 determines whether or not the driver has selected the preceding vehicle following mode based on the driving support mode selection signal received from the mode selection switch 36 (S21).

  When the preceding vehicle following mode is selected (S21; Yes), the ECU 10 determines whether or not both end positions of the lane are detected based on the sensor information and the like (S22). If both lane end positions are detected (S22; Yes), the first travel route is calculated as the target travel route (S23). When the preceding vehicle is detected, the preceding vehicle speed is used as the target vehicle speed, and when the preceding vehicle is not detected, the set vehicle speed is used as the target vehicle speed.

  In the calculation processing of the first traveling route, the ECU 10 determines a predetermined period (for example, 3 seconds) based on the set vehicle speed, both ends of the lane, the lane width, the speed limit, the vehicle speed, the vertical acceleration, the yaw rate, the steering angle, the lateral acceleration, and the like. ) Is calculated. The target position of the traveling route R1 is set so that the vehicle travels near the center of the lane in a straight section, and travels on the inside of the curve so as to increase the turning radius in a curve section. Further, the target speed of the traveling route R1 is set so that the lowest speed among the set vehicle speed, the vehicle speed limit based on the traffic sign, and the vehicle speed limit defined by the curve curvature is set as the upper limit speed.

If the lane end positions have not been detected (S22; No), the ECU 10 determines whether a preceding vehicle has been detected based on sensor information and the like (S24).
In a case where the lane end positions have not been detected but the preceding vehicle has been detected (S24; Yes), the ECU 10 calculates the second travel route as the target travel route (S25). In the calculation process of the second traveling route, the ECU 10 maintains a predetermined inter-vehicle distance between the preceding vehicle and the vehicle 1 based on the preceding vehicle trajectory information (position and speed) of the preceding vehicle acquired from the sensor information and the like. The traveling route R2 for a predetermined period is calculated so as to follow the behavior (position and speed) of the preceding vehicle with a delay of the traveling time of the inter-vehicle distance.

  Further, when the preceding vehicle following mode is not selected (S21; No), and when the preceding vehicle following mode is selected, neither the end position of the lane nor the preceding vehicle is detected (S24; No), the ECU 10 The third travel route is calculated as the target travel route (S26). In the calculation process of the third traveling route, the ECU 10 calculates the traveling route R3 for a predetermined period estimated from the current behavior of the vehicle 1 based on the vehicle operation information, the traveling behavior information, and the like.

Next, a detailed processing flow of the traveling route correction processing (S13b) of FIG. 10 will be described with reference to FIG.
First, the ECU 10 acquires obstacle information (presence of a preceding vehicle or an obstacle, position, speed, and the like) using various types of information acquired in the information acquisition process (S11) (S31).

  If the ECU 10 determines that no obstacle is detected based on the obstacle information (S32; No), the ECU 10 ends the process, but determines that an obstacle is detected (S32; Yes). A speed distribution area (see FIG. 6) is set based on obstacle information, running behavior information of the vehicle 1, and the like (S33).

  Next, the ECU 10 reads the evaluation function J, the constraint condition, and the vehicle model according to the sensor / switch information (for example, the driving support mode selection signal) (S34). Then, the ECU 10 uses the evaluation function J based on the target travel route, the speed distribution area (S33), the evaluation function J, the constraint condition, the vehicle model, the sensor / switch information, and the like calculated in the travel route calculation process (S13). Then, the process of optimizing the corrected traveling route is executed (S35). In this optimization process, the evaluation value of the evaluation function J is calculated for a plurality of corrected travel route candidates repeatedly until the optimized corrected travel route is calculated. A corrected traveling route that minimizes this evaluation value is output.

Next, a detailed process flow of the automatic collision prevention control process (S14) of FIG. 10 will be described with reference to FIG.
First, the ECU 10 acquires obstacle information (presence of a preceding vehicle or an obstacle, position, speed, and the like) using various types of information acquired in the information acquisition process (S11) (S41).

  Then, the ECU 10 calculates a predicted traveling route for a predetermined period (for example, 3 seconds) of the vehicle 1 predicted from the current behavior state of the vehicle 1 (that is, vehicle speed, acceleration, yaw rate, steering angle, lateral acceleration, and the like). Then, it is determined whether or not an obstacle exists on the predicted traveling route (S42).

  When there is no obstacle on the predicted traveling route (S42; No), the ECU 10 ends the processing. On the other hand, when an obstacle exists on the predicted traveling route (S42; Yes), the ECU 10 calculates a time to collision (TTC = distance / relative speed) until the vehicle 1 collides with the obstacle (S43). Then, the ECU 10 performs a process of determining an alarm generation time based on the TTC (S44). In this process (S44), it is determined whether or not the TTC has matched a predetermined alarm generation time Ta (for example, 2 seconds).

  If the TTC matches Ta (S44; Yes), the ECU 10 executes a warning generation process (S45) and ends the process. In this alarm generation processing, an alarm screen is displayed on a display unit (a navigation screen or the like), and an alarm sound is generated from a speaker. Thereby, the driver can execute the brake operation.

  On the other hand, when the TTC does not match Ta (S44; No), the ECU 10 determines whether the TTC is equal to or shorter than a predetermined automatic brake occurrence time Tth (for example, 1 second) (S46).

  When the TTC exceeds Tth (S46; No), the ECU 10 ends the process because there is no possibility of collision. On the other hand, when the TTC is equal to or smaller than Tth (S46; Yes), the ECU 10 generates a second request signal (S47) because there is a possibility of collision, and ends the processing. The second request signal is a brake request signal set to generate a predetermined large braking force for the brake control system 32 in order to rapidly decelerate the vehicle 1 and avoid a collision with an obstacle.

  The second request signal is generated only when there is a possibility of collision with an obstacle. That is, the second request signal is not necessarily generated every time the driving support control is repeatedly executed (for example, 0.1 second) in FIG. 10, but is generated only in an emergency where a collision may occur. When the obstacle does not exist on the predicted traveling route or when there is no possibility of collision, the ECU 10 may generate a formal second request signal (Null signal) including a Null value.

Next, a detailed processing flow of the system control processing (S15) of FIG. 10 will be described with reference to FIG.
First, among the request signals output from the ECU 10 to the external control system, a brake request signal related to brake control will be described.

  The ECU 10 determines whether or not the second request signal (brake request signal) has been generated by the automatic collision prevention control process (S14) when outputting the request signal to the outside (S51). If a substantial second request signal (not a Null signal) is not generated (S51; No), it is not an emergency, so the ECU 10 generates the first request generated by the traveling route control process (S13). The signal is output to the outside (S52), and the process ends.

  On the other hand, if the second request signal has been generated (S51; Yes), it is an emergency, so the ECU 10 outputs the second request signal (brake request signal) to the outside (the brake control system 32) ( S53), the process ends.

  Note that the ECU 10 outputs the engine request signal and the steering request signal included in the first request signal to the outside (the engine control system 31 and the steering control system 31 regardless of the presence or absence of the second request signal). Output to the control system 33).

  For example, in the preceding vehicle following mode, when the automatic speed / steering control is executed, and when the traveling route control process (S13) is appropriately executed, the obstacle is safely secured by the traveling route correction process (S13b). The corrected travel route is calculated so as to avoid this. Therefore, the second request signal is not generated by the automatic collision prevention control processing (S14). Therefore, the second request signal is generated, for example, when the traveling route control process (S13) is not completely completed within a predetermined calculation time due to a high calculation load (timeout). Therefore, in this case (S51; Yes), the brake request signal is based on the second request signal. On the other hand, since the first request signal may not be updated to the optimum value or the signal itself may not be generated (Null value), the engine request signal and the steering request signal may be set to predetermined values.

Next, with reference to FIG. 15 and FIG. 16, a description will be given of an alarm generation timing change process according to the present embodiment.
FIG. 15 shows a situation where the vehicle (preceding vehicle) 4 has begun to rapidly decelerate while the vehicle 1 is traveling on the traveling path 7. At this time, the ECU 10 (the traveling route control unit 10a) calculates the corrected traveling route Rc. On the other hand, the ECU 10 (automatic collision prevention control unit 10b) calculates the predicted traveling route Re. Since the preceding vehicle 4 is located on the predicted traveling route Re, there is a risk of collision.

  If the vehicle 1 is traveling on the optimized corrected traveling route Rc, there is no collision with the preceding vehicle 4. However, when the vehicle 1 continues to travel on the predicted traveling route Re and the TTC reaches the alarm generation time Ta (for example, 2 seconds), an alarm is generated, and then the TTC becomes the automatic brake generation time Tth (for example, 1 second). When it reaches, the automatic brake is activated.

  In the present embodiment, when there is a possibility of collision, the alarm generation time Ta is changed from the reference value (2 seconds) according to the difference between the corrected travel route and the predicted travel route, and the alarm generation timing is changed. That is, when it is determined that the vehicle 1 is traveling on the corrected traveling route, the alarm generation timing is delayed, and unnecessary alarm generation is suppressed. When it is determined that the vehicle 1 is deviating from the corrected travel route, the warning timing is advanced, so that the driver can execute the collision avoidance operation with a margin by early warning.

  In FIG. 15, the difference E is the target position Pc of the corrected travel route Rc and the predicted position Pe of the predicted travel route Re after a predetermined time Tb (for example, Tb = 1.5 seconds; 0 <Tb <Ta) from the present. Is the distance between In the present embodiment, if the difference E is between the first threshold value Eth1 (for example, 0.2 m) and the second threshold value Eth2 (for example, 0.4 m), the reference value is used as the warning time Ta.

On the other hand, if the difference E is smaller than the first threshold value Eth1 and the difference E does not tend to increase with time, the vehicle 1 is considered to travel along the corrected traveling route Rc. Therefore, in this case, the alarm generation time Ta is changed to a small value according to the magnitude of the difference E (that is, as the difference is closer to zero) (for example, when the difference E is zero, Ta = 1. 6 seconds). The ECU 10 stores the difference E for a predetermined time in a memory in order to calculate the time change of the difference E.

If the difference E is larger than the second threshold value Eth2 and the difference E tends to increase with time, the vehicle 1 is considered to deviate from the corrected traveling route Rc. Therefore, in this case, the alarm generation time Ta is changed to a large value (for example, Ta = 2.4 seconds at maximum) according to the magnitude of the difference E (that is, the larger the difference).

  In the above embodiment, the difference E is the distance between the target position and the predicted position a predetermined time ahead. However, the present invention is not limited to this. Alternatively, the difference E may be an integrated value of a difference (absolute value) of a predetermined period (for example, 3 seconds) between the corrected traveling route and the predicted traveling route.

Next, a detailed processing flow of the alarm occurrence timing change processing will be described with reference to FIG.
The ECU (automatic collision prevention control unit 10b) repeatedly executes this processing flow every predetermined time (for example, every 0.1 second). First, the ECU 10 uses a variety of information stored in the memory in the information acquisition process (S11) for a predetermined period (for example, 3 seconds) of the vehicle 1 predicted from the current behavior state of the vehicle 1. The predicted travel route is calculated (S61). Then, the ECU 10 determines whether or not an obstacle (for example, a preceding vehicle) exists on the predicted traveling route (S62).

  If there is no obstacle (S62; No), the ECU 10 ends the processing. On the other hand, when there is an obstacle (S62; Yes), the ECU 10 calculates the difference E between the corrected travel route and the predicted travel route at the predetermined time Tb (S63), and determines the magnitude of the difference E (S64). ).

  If the difference E is smaller than the first threshold value Rth1 (S64; E <Eth1), the ECU 10 determines whether the difference E is increasing with time (S65). If the time variation of the difference E does not tend to increase (S65; No), the ECU 10 delays the warning timing according to the magnitude of the difference E (that is, the warning time Ta is set to a small value).

  On the other hand, when the difference E is larger than the second threshold value Rth2 (S64; Eth2 <E), the ECU 10 determines whether the difference E is increasing with time (S67). If the time variation of the difference E is increasing (S67; Yes), the ECU 10 advances the warning timing according to the magnitude of the difference E (that is, the warning time Ta is set to a large value).

  Further, when the difference E is between the first threshold value Eth1 and the second threshold value Eth2 (S64; Yes), when the difference E is smaller than the first threshold value Rth1 but increases with time (S65; Yes), When the difference E is larger than the second threshold value Rth2 but does not increase with time (S67; No), the ECU 10 sets the alarm time Ta to the reference value (2 seconds) (S69), and ends the processing. I do. Note that the processing steps S65 and S67 may be omitted.

Next, the operation of the vehicle control device according to the present embodiment will be described.
The present embodiment is a vehicle control device (ECU) 10 for repeatedly updating a target traveling route R of the vehicle 1 and a traveling route control unit 10a for avoiding collision with an obstacle (for example, a preceding vehicle 4). An automatic collision prevention control unit 10b for executing an automatic collision prevention control process (S14; S41-S47). When an obstacle (preceding vehicle 4) is detected, the traveling route control unit 10a calculates the target traveling route Rc so as to avoid the obstacle (S13). The automatic collision prevention control unit 10b calculates a predicted traveling route Re based on the current traveling behavior of the vehicle 1 (S42), and a time to collision TTC with an obstacle (preceding vehicle 4) existing on the predicted traveling route Re. Is calculated (S43), and when the time to collision TTC reaches a predetermined time (alarm generation time Ta) (S44; Yes), an alarm is generated (S45). The automatic collision prevention control unit 10b changes the alarm generation time (alarm generation time Ta) according to the difference E between the target travel route Rc and the predicted travel route Re (alarm generation time change processing; S61-S69).

  As described above, in the present embodiment, when an obstacle (preceding vehicle 4) is detected, the traveling route control unit 10a calculates the target traveling route (corrected traveling route) Rc so as to avoid the obstacle, and automatically calculates the target traveling route. The collision prevention control unit 10b generates an alarm when the time to collision TTC reaches the alarm generation time Ta based on the predicted traveling route Re (S45). Even if the vehicle 1 is traveling on the target traveling route Rc so as not to collide with the obstacle, the automatic collision prevention control unit 10b determines that the vehicle 1 will collide with the obstacle after the collision allowance time TTC based on the predicted traveling route Re. It may be determined. In this case, an alarm is generated when the TTC reaches a predetermined time even though the vehicle does not actually collide with an obstacle. Therefore, in the present embodiment, the automatic collision prevention control unit 10b is configured to change the alarm generation timing to an appropriate timing according to the difference E between the target traveling route Rc and the predicted traveling route Re.

  Specifically, in the present embodiment, when the difference E is less than the first threshold value Eth1 (S64; E <Eth1), the automatic collision prevention control unit 10b delays the alarm generation timing (S66). As a result, in the present embodiment, when the possibility of collision with an obstacle is low, it is possible to suppress the occurrence of unnecessary alarms.

  On the other hand, in the present embodiment, when the difference E exceeds the second threshold value Eth2 (S64; Eth2 <E), the automatic collision prevention control unit 10b advances the alarm generation timing (S68). Thus, in the present embodiment, when the possibility of collision with an obstacle is high, it is possible to generate an alarm early and avoid collision reliably.

  Further, specifically, in the present embodiment, the difference E is a target position Pc of the vehicle 1 at a predetermined time ahead on the target travel route Rc and a predicted position Pe of the vehicle 1 at a predetermined time ahead on the predicted travel route Re. Is the distance between

1 vehicle 3 vehicle 5 road 5a, 5c straight section 5b curve section 5 _L, 5 _R lane 6 _L, 6 _R lane end portions 7 traveling path 40 velocity distribution region a, b, c, d, etc. the relative velocity V _lim allowable upper the value 100 vehicle control system D the width dimension D ₀ safety distance R target traveling route R1 first travel path R2 second travel path R3 third travel path Rc1, Rc2, Rc3 corrected travel route X clearance

Claims (3)

A vehicle control device,
A traveling route control unit that repeatedly updates a target traveling route of the vehicle;
A collision prevention control unit that issues an alarm to avoid collision with an obstacle,
The traveling route control unit, when an obstacle is detected, executes a traveling route correction process of calculating the target traveling route so as to avoid the obstacle,
The travel route control unit may include, in the travel route correction processing,
At least from the obstacle to the vehicle, a speed distribution region that defines a distribution of an allowable upper limit value of the relative speed of the vehicle with respect to the obstacle is set, and the allowable upper limit value in the speed distribution region is a distance from the obstacle. Is set to increase as the distance increases,
A plurality of corrections for correcting the target travel route and causing the vehicle to travel in the speed distribution area so that the relative speed of the vehicle to the obstacle does not exceed the allowable upper limit value in the speed distribution area. Calculate the driving route,
A plurality of corrected travel routes corrected for these target travel routes are evaluated by a predetermined evaluation function, and one corrected travel route is selected in accordance with the evaluation;
The collision prevention control unit executes a collision prevention control process independently of the traveling route control unit, and in the collision prevention control process, calculates a predicted traveling route based on a current traveling behavior of the vehicle, It is configured to calculate a collision margin time with an obstacle existing on the predicted traveling route, and to generate the warning when the collision margin time reaches a predetermined time,
The collision prevention control unit, according to a difference between the target travel route and the predicted travel route, changes the timing of the warning,
The vehicle control device, wherein the collision prevention control unit delays a timing of generating the warning when the difference is less than a predetermined first threshold.   2. The vehicle control device according to claim 1, wherein the collision prevention control unit advances the alarm generation timing when the difference exceeds a predetermined second threshold. 3.   The said difference is a distance between the target position of the said vehicle of a predetermined time ahead on the said target driving | running route, and the predicted position of the said vehicle of a predetermined time ahead on the said predicted driving | running route, The claim 1 or Claim. 3. The vehicle control device according to 2.

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