JP2019043195A - Vehicle control device - Google Patents

Abstract

To provide a vehicle control device that can generate an alarm at an appropriate time.SOLUTION: A vehicle control device (an ECU) comprises: a travel route control part that repeatedly updates a target travel route R for a vehicle; and an automatic collision prevention control part that executes automatic collision prevention control processing for avoiding a collision with an obstacle. The travel route control part, when detecting an obstacle, calculates a target travel routes Rc for the vehicle to avoid the obstacle. The automatic collision prevention control part is configured to calculate a predicted travel route Re S42, calculate time TTC allowing the vehicle to avoid a collision with an obstacle existing on the predicted travel route Re S43, and generate an alarm when the TTC reaches an alarm-generation time Ta S45. The automatic collision prevention control part changes timing for generating an alarm according to a difference E between the target travel route Rc and the predicted travel route Re (alarm-generation timing change processing).SELECTED DRAWING: Figure 13

Description

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

  During emergency avoidance of an obstacle, either braking avoidance (only brake operation) or steering avoidance (only steering operation) is selected according to the vehicle speed at that time, and the target travel route is calculated using optimization processing Has been proposed (see, for example, Patent Document 1). In this technique, when the braking avoidance is selected, the calculation conditions are simplified only to the movement in the longitudinal direction (the vehicle longitudinal direction). In addition, when the steering avoidance is selected, the calculation condition is simplified only to the movement in the lateral direction (the vehicle width direction). As described above, in this technology, since the calculation load is reduced in an emergency, it is possible to shorten the calculation time while securing high calculation accuracy.

JP, 2010-155545, A

  In addition, in a vehicle in which automatic collision prevention control is performed, automatic braking is automatically activated after a warning to the driver. However, although the vehicle travels along the obstacle-avoidable target travel route, there is a possibility that 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 is a vehicle control device, and a collision control system that repeatedly updates a target traveling route of a vehicle and generates a warning to avoid a collision with an obstacle. The travel control unit is configured to calculate a target travel route so as to avoid the obstacle when the obstacle is detected, and the collision prevention control unit is configured to The predicted travel route is calculated based on the current travel behavior of the vehicle, the collision margin time with the invitation present on the predicted travel path is calculated, and an alarm is generated when the collision margin time reaches a predetermined time. The collision prevention control unit is configured to change the alarm generation time according to the difference between the target travel route and the predicted travel route.

  According to the present invention configured as described above, when an obstacle (preceding vehicle) is detected, the traveling route control unit calculates a target traveling route so as to avoid the obstacle, and the collision prevention control unit An alarm is generated when the collision margin time reaches a predetermined time based on the predicted travel route. Even if the vehicle travels 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 margin time TTC based on the predicted traveling route. . In this case, although the vehicle does not actually collide with the obstacle, an alarm is generated when the TTC reaches a predetermined time. Therefore, in the present invention, the collision prevention control unit is configured to change the warning occurrence timing to an appropriate timing according to the difference between the target travel route and the predicted travel route.

  Further, in the present invention, preferably, the collision prevention control unit delays an alarm occurrence time when the difference is less than the first threshold. According to the present invention configured as described above, when the possibility of a collision with an obstacle is low, it is possible to suppress the generation of unnecessary alarms.

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

  Further, specifically, in the present invention, the difference is a distance between a target position of a vehicle ahead of a predetermined time on the target traveling route and a predicted position of the vehicle ahead of the predetermined time on the predicted traveling 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 block 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. It is explanatory drawing of the 1st driving | running route in embodiment of this invention. It is explanatory drawing of the 2nd driving | running route in embodiment of this 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. It is an explanatory view showing the relation of the upper limit of passing speed between the obstacle and vehicles in the obstacle avoidance control of the embodiment of the present invention and the clearance. It is explanatory drawing of the driving | running route correction process of embodiment of this invention. It is an explanatory view of a vehicle model of an embodiment of the present invention. It is a processing flow of driving assistance control in an embodiment of the present invention. It is a processing flow of a travel route calculation process in an embodiment of the present invention. It is a processing flow of the travel route correction processing in the embodiment of the present invention. It is a processing flow of automatic collision prevention control processing in an embodiment of the present invention. It is a processing flow of system control processing in an embodiment of the present invention. It is an explanatory view of alarm generation time change processing in an embodiment of the present invention. It is a processing flow of alarm generation 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 attached drawings. First, the configuration of the vehicle control system will be described with reference to FIGS. 1 and 2. FIG. 1 is a block diagram of a vehicle control system, and FIG. 2 is a control block diagram of the vehicle control system.

  The vehicle control system 100 according to 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 includes a vehicle control unit (ECU) 10, a plurality of sensors and switches, a plurality of control systems, and a user input for a driving support mode. And a driver operation unit 35 for performing the operation. The plurality of sensors and switches include an on-vehicle 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). , An accelerator sensor 27, a brake sensor 28, a positioning system 29, and a navigation system 30 are included. Further, 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 compartment of the vehicle 1 so as to be operable by the driver, and a mode selection switch 36 for selecting a desired driving support mode from a plurality of driving support modes is selected. A set vehicle speed input unit 37 is provided to input a set vehicle speed according to the driving support 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. Further, when the driver operates the set vehicle speed input unit 37, a set vehicle speed signal is output.

  The ECU 10 is constituted by a computer provided with a CPU, a memory for storing various programs, an input / output device and the like. The ECU 10 controls 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, it is possible to output request signals for appropriately operating the engine system, the brake system, and the steering system.

  The on-vehicle camera 21 captures an image of the surroundings of the vehicle 1 and outputs the captured image data. The ECU 10 identifies an object (for example, a vehicle, a pedestrian, a road, a lane line (white line, yellow line), a traffic signal, a traffic sign, a stop line, an intersection, an obstacle, etc.) based on image data. Do. The ECU 10 may acquire information on the object from the outside via the on-vehicle communication device by traffic infrastructure, inter-vehicle communication, or the like.

  The millimeter wave radar 22 is a measurement device that measures the position and speed of an object (in particular, a preceding vehicle, a parked vehicle, a pedestrian, an obstacle, etc.), and transmits radio waves (transmission waves) toward the front of the vehicle 1 And the reflected wave generated by the transmission wave being reflected by the object. Then, the millimeter wave radar 22 measures the distance between the vehicle 1 and the object (for example, the distance between the vehicles) and the relative velocity of the object with respect to the vehicle 1 based on the transmission wave and the reception wave. In the present embodiment, in place of the millimeter wave radar 22, a laser radar, an ultrasonic sensor, or the like may be used to measure the distance to the object or the relative velocity. Also, a plurality of sensors may be used to construct a position and velocity measurement device.

The vehicle speed sensor 23 detects the absolute speed of the vehicle 1.
The acceleration sensor 24 detects the acceleration of the vehicle 1 (longitudinal acceleration in the longitudinal direction, lateral acceleration in the lateral direction). The acceleration includes an acceleration side (positive) and a deceleration side (negative).
The yaw rate sensor 25 detects the yaw rate of the vehicle 1.
The steering angle sensor 26 detects the rotation angle (steering angle) of the steering wheel of the vehicle 1.
The accelerator sensor 27 detects the depression amount of the accelerator pedal.
The brake sensor 28 detects the depression amount 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 ECU 10 with map information. The ECU 10 specifies a road, an intersection, a traffic signal, a building, etc. existing around the vehicle 1 (particularly, ahead of the traveling direction) based on the map information and the current vehicle position information. 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, to the engine control system 31, an engine output change request signal for requesting a change of the engine output.

  The brake control system 32 is a controller for controlling a brake system of the vehicle 1. When it is necessary to decelerate the vehicle 1, the ECU 10 outputs a brake request signal that requests 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, to the steering control system 33, a steering direction change request signal for requesting a change in the steering direction.

  As shown in FIG. 2, the ECU 10 is provided with a single CPU functioning 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 10 c processes input information received from the plurality of sensors / switches and the driver operation unit 35. The travel route control unit 10a and the automatic collision prevention control unit 10b execute arithmetic processing using the processed input information. In the present embodiment, automatic collision avoidance control, which is highly urgent automatic emergency avoidance control, is configured to be executed independently of normal travel route control. In the present embodiment, although a single CPU is configured to execute a plurality of the above functions, the present invention is not limited to this, and different CPUs may be configured to execute each function.

  In the present embodiment, the automatic emergency avoidance control requests at least one of the engine control system 31, the brake control system 32, and the steering control system 33 to change the behavior of the vehicle 1 in an emergency. It is control to generate.

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

  Next, a 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, basic control mode) are provided as the driving support mode.

<Preceding vehicle tracking mode>
The preceding vehicle follow-up mode is basically a mode in which the vehicle 1 follows the preceding vehicle while maintaining a predetermined inter-vehicle distance between the vehicle 1 and the preceding vehicle according to the vehicle speed. Automatic steering control, speed control (engine control, brake control), obstacle avoidance control (speed control and steering control).

  In the preceding vehicle follow-up 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 there is a preceding vehicle. Here, both ends of the lane are both ends of the lane on which the vehicle 1 travels (division lines such as white lines, road ends, curbs, median dividers, guard rails, etc.), and the boundaries between adjacent lanes and sidewalks etc. is there. The ECU 10 as the traveling path end detection unit detects both ends of the lane from the image data captured by the on-vehicle camera 21. Further, both ends of the lane may be detected from the map information of the navigation system 30. However, for example, when traveling on a plain where there is no lane instead of a road on which the vehicle 1 is maintained, or when reading of image data from the on-vehicle camera 21 is defective, the lane ends may not be detected.

  In the above embodiment, the ECU 10 is used as the traveling path end detection unit. However, the present invention is not limited thereto. The on-vehicle camera 21 as the traveling path end detection unit may detect both ends of the lane. The on-vehicle camera 21 and the ECU 10 as the unit detection unit may cooperate to detect both ends of the lane.

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

  In the above embodiment, the ECU 10 is used as the preceding vehicle detection unit. However, the present invention is not limited to this. The on-vehicle camera 21 as the preceding vehicle detection unit may detect another vehicle traveling in front. The camera 21 and the millimeter wave radar 22 may form part of the preceding vehicle detection unit.

(Advanced vehicle tracking mode: lane detection is possible)
First, when both ends of the lane are detected, the vehicle 1 is steering-controlled to travel near the center of the lane, and the vehicle speed is input by the driver using the set vehicle speed input unit 37 or by the system 100 in advance based on predetermined processing. The speed control is performed to maintain the set vehicle speed (constant speed). If the set vehicle speed is greater than the limit vehicle speed (a limit speed defined according to the velocity signs and the curvature of the curve), the limit vehicle speed is prioritized, and the vehicle speed of the vehicle 1 is limited to the limit vehicle speed. The speed limit defined in accordance with the curvature of the curve is calculated according to a predetermined formula, and the larger the curvature of the curve (the smaller the curvature radius), the lower the speed.

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

(Preceding car following mode: lane detection not possible, preceding car present)
In addition, when both ends of the lane are not detected, and there is a preceding vehicle, the vehicle 1 is steering-controlled to follow the traveling locus of the preceding vehicle, and the speed on the traveling locus of the preceding vehicle The speed is controlled to follow the

(Advanced vehicle follow-up 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 road can not be identified (division line can not be detected, etc. can not be followed). In this case, the steering control is performed by the driver operating the steering wheel, the accelerator pedal, and the brake pedal such that the current driving behavior (steering angle, yaw rate, vehicle speed, acceleration, etc.) is maintained or changed by the driver's intention. And execute speed control.

  In the following vehicle follow-up mode, obstacle avoidance control (speed control and steering control) described later is further automatically executed regardless of the presence or absence of the preceding vehicle and whether or not both ends of the lane can be detected.

<Automatic speed control mode>
The automatic speed control mode is a mode in which speed control is performed so as to maintain a predetermined set vehicle speed (constant speed) preset by the driver or by the system 100. Automatic speed control by the vehicle control system 100 It involves engine control, brake control), obstacle avoidance control (speed control), but no steering control. In this automatic speed control mode, the vehicle 1 travels to maintain the set vehicle speed, but may be accelerated beyond the set vehicle speed by depression of the accelerator pedal by the driver. When the driver performs a brake operation, the driver's intention is given priority, and the vehicle speed is reduced from the set vehicle speed. In addition, when it 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. Be done.

<Speed limit mode>
The speed limit mode is a mode in which speed control is performed so that the vehicle speed of the vehicle 1 does not exceed the speed limit by the speed indicator or the set speed set by the driver. Automatic speed control by the vehicle control system 100 Engine control). The speed limit may be specified by the ECU 10 performing image recognition processing on a speed sign captured by the on-vehicle camera 21 or image data of a speed indication on the road surface, or may be received through external wireless communication. In the speed limit mode, even if the driver depresses the accelerator pedal so as to exceed the speed limit, the vehicle 1 is accelerated only to the speed limit.

<Basic control mode>
Further, the basic control mode is a mode (off mode) when the driving support mode is not selected by the driver operation unit 35, and automatic steering control and speed control by the vehicle control system 100 are not performed. However, the automatic collision prevention control is configured to be executed, and in this control, when there is a possibility that the vehicle 1 collides with the preceding vehicle, etc., the brake control is automatically executed to avoid the collision. Ru. The automatic collision prevention control is also performed 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 (speed control only or speed control and steering control) described later is further executed.

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

  In addition, the travel route (the first travel route to the third travel route) in FIGS. 3 to 5 is an obstacle related to an obstacle (including a parked vehicle, a pedestrian, etc.) on the travel road where the vehicle 1 travels or around the travel road. It is calculated based on the shape of the traveling path, the traveling path 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 travel routes can be reduced.

In the following, for easy understanding, each travel route calculated when the vehicle 1 travels on the road 5 including the straight section 5a, the curve section 5b, and the straight section 5c will be described. The road 5 is composed of left and right lanes 5 _L and 5 _R. At the present time, it is assumed that the vehicle 1 is traveling on the lane 5 _L of the straight section 5 a.

(First travel route)
As shown in FIG. 3, the first travel route R1 is set for a predetermined period so as to keep the vehicle 1 traveling in the lane 5 _L , which is a travel path, in accordance with the shape of the road 5. Specifically, the first travel route R1 is set so that the vehicle 1 maintains traveling near the center of the lane 5 _{L in} the straight line segments 5a and 5c, and the vehicle 1 is from the width direction center of the lane 5 _{L in} the curve segment 5b. It is also set to travel on the inside or in side (the center O side of the radius of curvature L of the curve section).

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

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 amount Ws is calculated based on the curvature radius L, the lane width W, and the width dimension D of the vehicle 1 (a prescribed value stored in the memory of the ECU 10). Then, the ECU 10 sets a plurality of target positions P1_k of the first travel route R1 so as to smoothly connect the central position P1_c of the curve section 5b and the widthwise central position of the straight sections 5a and 5c. Before and after entering the curve section 5b, the first travel route R1 may be set on the in-side of the straight sections 5a and 5c.

  The target speed V1_k at each target position P1_k of the first travel route R1 is, in principle, a predetermined set vehicle speed preset by the driver by the set vehicle speed input unit 37 of the driver operation unit 35 or by the system 100 Set to). However, when the set vehicle speed exceeds the speed limit acquired from the speed mark S or the like or the speed limit defined in accordance with the curvature radius L of the curve section 5b, the target speed of each target position P1_k on the traveling route V1_k is limited to the slower speed limit of the two speed limits. Furthermore, 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 (ie, 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 such that the vehicle speed approaches the set vehicle speed.

(Second 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. The ECU 10 continues the position and speed of the preceding vehicle 3 on the lane 5 _L on which the vehicle 1 travels based on the image data by the on-vehicle camera 21, the measurement data by the millimeter wave radar 22, and the vehicle speed of the vehicle 1 by the vehicle speed sensor 23. These are calculated as leading vehicle trajectory information, and the traveling trajectory of the leading vehicle 3 is set as a second traveling route R2 (target position P2_k, target velocity V2_k) based on the leading vehicle trajectory information.

(Third travel route)
Further, as shown in FIG. 5, the third travel 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 travel route R3 is set based on the position and speed estimated from the current travel behavior of the vehicle 1.

  The ECU 10 calculates a target position P3_k of the third travel 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 travel route R3 does not approach or intersect the lane end.

  Further, the ECU 10 calculates a target speed V3_k of the third travel route R3 for a predetermined period based on the current vehicle speed and acceleration of the vehicle 1. If the target speed V3_k exceeds the speed limit acquired from the speed mark 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 travel 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 from a sensor or the like. , Is configured to select one.

  When the preceding vehicle follow-up mode is selected, when both ends of the lane are detected, the first travel 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 is the target speed.

  On the other hand, when the preceding vehicle follow-up mode is selected, the second travel route is applied when the both ends of the lane are not detected and the preceding vehicle is detected. In this case, the target speed is set in accordance with the vehicle speed of the preceding vehicle. Further, at the time of selection of the preceding vehicle follow-up mode, the third travel route is applied when both ends of the lane are not detected and no preceding vehicle is also detected.

  Further, at the time of selection of the automatic speed control mode, the third travel route is applied. The automatic speed control mode is a mode for automatically executing speed control as described above, and the set vehicle speed set by the set vehicle speed input unit 37 becomes the target speed. In addition, steering control is performed 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 the 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 in accordance with the depression amount of the accelerator pedal by the driver. In addition, steering control is performed based on the operation of the steering wheel by the driver.

  Further, at the time of selection of the basic control mode (off mode), 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, obstacle avoidance control executed in the vehicle control system 100 according to the present embodiment and travel route correction processing associated therewith will be described with reference to FIGS. 6 is an explanatory view of obstacle avoidance control, FIG. 7 is an explanatory view showing a relationship between an allowable upper limit value of passing speed between an obstacle and a vehicle in the obstacle avoidance control and clearance, and FIG. FIG. 9 is an explanatory view of a vehicle model.
In FIG. 6, the vehicle 1 travels on a traveling path (lane) 7 and is about to pass the vehicle 3 by passing the vehicle 3 while driving or stopping.

  Generally, when passing (or overtaking) an obstacle on the road or in the vicinity of the road (for example, a preceding vehicle, a parked vehicle, a pedestrian, etc.), the driver of the vehicle 1 operates in the 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 vehicle 1 is decelerated to a speed that the driver of the vehicle 1 feels safe. More specifically, the smaller the clearance, the less the clearance for the obstacle, in order to avoid the danger that the preceding vehicle will suddenly change course, the pedestrian will come out from the blind spot of the obstacle, or the door of the parked vehicle will open. The relative speed is reduced.

  In general, when approaching the preceding vehicle from the rear, the driver of the vehicle 1 adjusts the speed (relative speed) in accordance with the inter-vehicle distance (longitudinal distance) along the traveling direction. Specifically, when the inter-vehicle distance is large, the approach speed (relative speed) is maintained large, but when the inter-vehicle distance is small, the approach speed is reduced. Then, at a predetermined inter-vehicle distance, the relative speed between both vehicles is zero. This is the same even if the preceding vehicle is a parked vehicle.

  In this manner, the driver drives the vehicle 1 to avoid danger while considering the relationship between the distance between the obstacle and the vehicle 1 (including the lateral distance and the longitudinal distance) and the relative speed. doing.

Therefore, in the present embodiment, as shown in FIG. 6, the vehicle 1 is placed around the obstacle (lateral area, rear area, etc.) with respect to the obstacle detected from the vehicle 1 (for example, the parked vehicle 3). And over the front area) or at least between the obstacle and the vehicle 1, configured to set a two-dimensional distribution (speed distribution area 40) defining an allowable upper limit value for the relative speed in the traveling direction of the vehicle 1 There is. In the velocity distribution area 40, an allowable upper limit value V _lim of the relative velocity is set at each point around the obstacle. In the present embodiment, obstacle avoidance control is performed to prevent the relative speed of the vehicle 1 with respect to the obstacle from exceeding the allowable upper limit value V _lim in the speed distribution region 40 in all the driving support modes.

As can be seen from FIG. 6, in principle, the lower the lateral distance and the vertical distance from the obstacle (the closer to the obstacle), the smaller the upper limit of the relative speed becomes. It is set. Further, in FIG. 6, equal relative velocity lines in which points having the same allowable upper limit value are connected are shown for ease of understanding. The equal relative speed lines a, b, c, d correspond to 0 km / h, 20 km / h, 40 km / h, and 60 km / h, respectively, of the allowable upper limit value V _lim . In this example, each equal relative velocity area is set to be substantially rectangular.

  The velocity distribution region 40 does not necessarily have to be set all around the obstacle, but at least behind the obstacle and on one side in the lateral direction of the obstacle where the vehicle 1 exists (in FIG. 6, the vehicle 3 In the right area of

As shown in FIG. 7, when the vehicle 1 travels 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 is D ₀ (safety distance). It is 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 in the lateral direction of the obstacle is _defined by V _lim = f (X) = k (X−D ₀ ) ² . Here, 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. Further, D _{0 is} also set depending on the type of obstacle or the like.

In the present embodiment, V _lim is defined to be a quadratic function of X. However, the present invention is not limited to this and may be defined by another function (for example, a linear function or the like). Further, although the allowable upper limit value V _{lim in} the lateral direction of the obstacle has been described with reference to FIG. 7, the same may be applied to all radial directions including the longitudinal direction of the obstacle. At that time, the coefficient k and the safety distance D ₀ can be set according to the direction from the obstacle.

The velocity distribution area 40 can be set based on various parameters. As parameters, for example, the relative speed between the vehicle 1 and the obstacle, the type of 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, etc. Can. That is, based on these parameters, the coefficient k and the safe distance D ₀ can be selected.

  Further, in the present embodiment, the obstacle includes a vehicle, a pedestrian, a bicycle, a cliff, a ditch, a hole, a falling object and the like. Furthermore, vehicles can be distinguished by cars, trucks, and motorcycles. Pedestrians are distinguishable among adults, children and groups.

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

  Further, the ECU 10 calculates the position and relative speed of the obstacle (vehicle 3) relative to the vehicle 1 and the absolute speed 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 the 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 the case of FIG. 6). Then, the ECU 10 performs 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 region 40. Therefore, the ECU 10 corrects the target travel route applied in accordance with 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 defined by the speed distribution area 40 at a certain target position, the target speed is decreased without changing the target position. (Route Rc1 in FIG. 6), change the target position on the bypass route so that the target velocity does not exceed the allowable upper limit without changing the target velocity (route Rc3 in FIG. 6), the target position and the target velocity Both are changed (path Rc2 in FIG. 6).

  For example, FIG. 5 shows a case where the calculated target travel route R travels at a central position (target position) in the width direction of the travel route 7 at 60 km / h (target speed). In this case, the parked vehicle 3 is present as an obstacle ahead, but as described above, this obstacle is not taken into consideration in the calculation of the target travel route R because of the reduction of the calculation load.

When traveling on the target traveling route R, the vehicle 1 crosses the equal relative velocity lines d, c, c, d of the velocity distribution area 40 in order. That is, the vehicle 1 traveling at 60 km / h enters an area inside the equal relative speed line d (permissible 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 of the target travel route R to the allowable upper limit value V _lim or less, and generates a corrected target travel route Rc1. That is, in the target travel route Rc1 after correction, the target speed gradually decreases to less than 40 km / h as the vehicle 3 approaches, so that the target vehicle speed becomes the allowable upper limit value V _lim or less at each target position. Thereafter, as the vehicle 3 is moved away, the target speed is gradually increased to the original 60 km / h.

  Further, the target travel route Rc3 is set so as to travel outside the equal relative speed line d (corresponding to a relative velocity of 60 km / h) without changing the target velocity (60 km / h) of the target travel route R. Route. The ECU 10 corrects the target travel route R so as to change the target position so that the target position is located on the equal relative speed line d or outside thereof in order to maintain the target speed of the target travel route R, Generate a route Rc3. 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.

  Further, 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 travel route Rc2, the target speed is not maintained at 60 km / h, and gradually decreases as the vehicle 3 is approached, and then gradually increases up to the original 60 km / h as the distance from the vehicle 3 Be done.

  The correction that changes 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, automatic speed control mode, speed limit mode, basic control mode).

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

  Further, as in the target travel route Rc2, a correction that changes both the target position and the target speed of the target travel route R can be applied to the driving support mode with speed control and steering control (for example, the following vehicle follow-up mode ).

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

  The ECU 10 stores the evaluation function J, the constraints and the vehicle model in a memory. The ECU 10 calculates a corrected travel route that minimizes the evaluation function J in the travel route correction process 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, velocity (longitudinal and lateral), acceleration (longitudinal and lateral), acceleration variation (longitudinal and lateral), yaw rate, lateral position relative to lane center, vehicle angle, steering It is a function for evaluating the difference between the target travel route and the correction travel route with respect to corners and other soft constraints.

  The evaluation factors include an evaluation factor related to the longitudinal behavior of the vehicle 1 (longitudinal evaluation factor: longitudinal velocity, acceleration, acceleration change amount, etc.) and an evaluation factor related to the lateral behavior of the vehicle 1 (horizontal evaluation factor) : Lateral velocity, acceleration, acceleration change amount, yaw rate, lateral position with respect to lane center, vehicle angle, steering angle, etc. are included.

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

Where 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), Wk is a weight value of the evaluation factor (for example, It is 0 <= Wk <= 1) (however, k = 1-n). Therefore, the evaluation function J of this embodiment is the difference between the physical quantity of the corrected travel path and the physical quantity of the target travel path (before correction) calculated on the assumption that no obstacle exists for the physical quantities of n evaluation factors. The sum of the squares is weighted, which corresponds to a value summed over the traveling path length for a predetermined period (for example, N = 3 seconds).

  The constraints include at least one constraint factor that limits the behavior of the vehicle 1. Each constraint factor is directly or indirectly related to any evaluation factor. Therefore, by restricting the behavior of the vehicle 1 (that is, the physical quantity of the evaluation factor) by the constraint condition, the optimization process by the evaluation function J can be converged early, and the calculation time can be shortened. The constraint conditions are set differently depending on the driving support mode.

Constraint factors in this example include, for example, speed (longitudinal and lateral), acceleration (longitudinal and lateral), acceleration variation (longitudinal and lateral), vehicle speed time deviation, lateral position relative to center position, inter-vehicle distance The distance time deviation, the steering angle, the steering angular velocity, the steering torque, the steering torque rate, the yaw rate, and the vehicle angle are included. An allowable numerical range is set to 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, it is possible to limit the maximum values of longitudinal G and lateral G on the corrected travel path by limiting the longitudinal and lateral accelerations that greatly affect the ride 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 when traveling, and at the same time to make the optimization process by the evaluation function J converge early. it can.

In FIG. 9 and the formula, m is the mass of the vehicle 1, I is the yawing moment of the vehicle 1, l is the wheel base, l _f is the distance between the vehicle center of gravity and the front axle, and l _r is between the vehicle center of gravity and the rear axle Distance, K _f is tire cornering power per front wheel, K _r is tire cornering power per rear wheel, V is vehicle speed of vehicle 1, δ is actual steering angle of front wheel, and β is side slip of 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 relative to the absolute space, and t is time.

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

  Next, with reference to FIGS. 10-14, the processing flow of the driving assistance control in the vehicle control system 100 of this embodiment is demonstrated. 10 is a processing flow of driving support control, FIG. 11 is a processing flow of travel route calculation processing, FIG. 12 is a processing flow of travel route correction processing, FIG. 13 is a processing flow of automatic collision prevention control processing, and FIG. Is the process flow of

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

  Next, the ECU 10 (input processing unit 10c) executes a predetermined information detection process using the various types of information acquired in the information acquisition process (S11) (S12). In the information detection process, the ECU 10 determines traveling path information (presence or absence of a straight section and a curved section, each section length, a curve, and the like of the traveling path shape around the vehicle 1 and the front area from the current vehicle position information, map information and sensor information. Section radius of curvature, lane width, both lanes position, number of lanes, number of intersections, existence of intersection, speed limit specified by curve curvature, etc., travel control information (speed limit, red light etc.) Position and velocity) is detected (S12a).

  Further, the ECU 10 detects vehicle operation information (steering angle, accelerator pedal depression amount, brake pedal depression amount, etc.) related to the vehicle operation by the driver from the switch information (S12b), and further, from the switch information and sensor information, the vehicle The traveling behavior information (vehicle speed, longitudinal acceleration, lateral acceleration, yaw rate, etc.) related to the behavior of 1 is detected (S12c).

Next, the ECU 10 (traveling route control unit 10a) executes traveling route control processing 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 traveling route calculation process (S13a), as described above, the first traveling route, the second traveling route, or the third traveling route is calculated.

  In the travel path correction process (S13b), the ECU 10 corrects the target travel path based on the obstacle information (for example, the parked vehicle 3 shown in FIG. 6). In the travel path correction process, the travel path is corrected so as to cause the vehicle 1 to avoid an obstacle by speed control and / or steering control according to the driving support 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 travel route finally calculated according to the selected driving support mode). A request signal to be output to the system 31, the brake control system 32, the steering control system 33) is generated. Specifically, the ECU 10 generates a first request signal (engine request signal, brake request signal, and the like) according to the target control amount of the engine, brake, and steering specified by the calculated target travel route (corrected travel route). Generate 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) to generate a second request signal (brake request signal). .

  Furthermore, 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 second request signal (see FIG. System control process; S15).

Next, with reference to FIG. 11, the detailed processing flow of the travel route calculation process (S13a) of FIG. 10 will be described.
First, the ECU 10 determines, based on the driving support mode selection signal received from the mode selection switch 36, whether the driver has selected the preceding vehicle tracking mode (S21).

  When the preceding vehicle follow-up mode is selected (S21; Yes), the ECU 10 determines whether or not the positions of both ends of the lane have been detected based on sensor information and the like (S22). When the both-lanes position is 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 process of the first travel route, the ECU 10 performs a predetermined period (for example, 3 seconds) based on the set vehicle speed, both lanes, lane width, speed limit, vehicle speed, longitudinal acceleration, yaw rate, steering angle, lateral acceleration, etc. The traveling route R1 of) is calculated. The target position of the travel route R1 is set so as to travel near the center of the lane in the straight section, and travel in the inward side of the curve so that the turning radius becomes larger in the curve section. Further, the target speed of the traveling route R1 is set to set the lowest speed as the upper limit speed among the set vehicle speed, the limited vehicle speed by the traffic sign, and the limited vehicle speed defined by the curve curvature.

In addition, when the position at both ends of the lane is not detected (S22; No), the ECU 10 determines whether the preceding vehicle is detected based on the sensor information and the like (S24).
Although the positions at both ends of the lane have not been detected, if 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 from the preceding vehicle trajectory information (position and speed) of the preceding vehicle acquired from the sensor information etc. A travel route R2 for a predetermined period is calculated so as to follow the behavior (position and speed) of the preceding vehicle with a delay by the time for traveling the inter-vehicle distance.

  Further, when the preceding vehicle follow-up mode is not selected (S21; No), and when the both ends of the lane and the preceding vehicle are not detected at the time of selecting the following vehicle follow-up mode (S24; No), the ECU 10 The third travel route is calculated as the target travel route (S26). In the calculation process of the third travel route, the ECU 10 calculates a travel route R3 for a predetermined period estimated from the current behavior of the vehicle 1 based on the vehicle operation information, the travel behavior information, and the like.

Next, with reference to FIG. 12, the detailed processing flow of the travel route correction process (S13b) of FIG. 10 will be described.
First, the ECU 10 acquires obstacle information (preceding vehicle, presence / absence of obstacle, position, speed, etc.) using various information acquired in the information acquisition process (S11) (S31).

  Then, if the ECU 10 determines that the obstacle is not detected based on the obstacle information (S32; No), the process ends, but if it is determined that the obstacle is detected (S32; Yes), A speed distribution area (see FIG. 6) is set based on obstacle information, travel behavior information of the vehicle 1, etc. (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 constraints, the vehicle model, the sensor / switch information, etc. calculated in the travel route calculation process (S13). Then, optimization processing of the correction travel route is executed (S35). In this optimization process, the evaluation value of the evaluation function J is calculated for a plurality of correction travel route candidates repeatedly until the optimized correction travel route is calculated. A corrected travel route that minimizes this evaluation value is output.

Next, with reference to FIG. 13, the detailed processing flow of the automatic collision prevention control process (S14) of FIG. 10 will be described.
First, the ECU 10 acquires obstacle information (preceding vehicle, presence / absence of obstacle, position, speed, etc.) using various information acquired in the information acquisition process (S11) (S41).

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

  When the obstacle does not exist on the predicted traveling route (S42; No), the ECU 10 ends the process. On the other hand, if an obstacle is present on the predicted travel route (S42: Yes), the ECU 10 calculates a collision margin time (TTC = distance / relative speed) until the vehicle 1 collides with the obstacle (S43). Then, the ECU 10 performs the process of determining the alarm generation time based on the TTC (S44). In this process (S44), it is determined whether the TTC matches a predetermined alarm generation time Ta (for example, 2 seconds).

  If the TTC matches Ta (S44; Yes), the ECU 10 executes an alarm generation process (S45), and ends the process. In this alarm generation process, a warning screen is displayed on the display unit (navigation screen etc.), and a warning sound is generated from the speaker. Thus, 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 less than or equal to a predetermined automatic braking occurrence time Tth (for example, one second) (S46).

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

  Note that 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 repetition execution time (for example, 0.1 seconds) of the driving support control of FIG. 10, but is generated only in an emergency where there is a possibility of a collision. In addition, the ECU 10 may generate a formal second request signal (Null signal) including a Null value, when there is no obstacle on the predicted traveling path or when there is no collision possibility.

Next, the detailed process flow of the system control process (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, the brake request signal related to the brake control will be described.

  The ECU 10 determines whether the second request signal (brake request signal) is generated by the automatic collision prevention control process (S14) when the request signal is output to the outside (S51). If the second request signal (not the Null signal) is not generated (S51: No), the ECU 10 determines that the first request generated by the travel route control process (S13) is not an emergency. The signal is output to the outside (S52), and the process is ended.

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

  As for the engine request signal and the steering request signal, the ECU 10 externally transmits the engine request signal and the steering request signal included in the first request signal regardless of the presence or absence of the second request signal (engine control system 31, steering Output to control system 33).

  For example, when the automatic speed / steering control is executed in the preceding vehicle follow-up mode, if the travel route control process (S13) is properly executed, the obstacle is safe by the travel route correction process (S13b). A corrected travel path is calculated to avoid. Therefore, the second request signal is not generated by the automatic collision prevention control process (S14). Therefore, the second request signal is generated, for example, when a high calculation load occurs and the travel route control process (S13) is not completely finished within a predetermined calculation time (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 have predetermined values.

Next, with reference to FIG.15 and FIG.16, the warning generation time change process by this embodiment is demonstrated.
FIG. 15 shows a situation where the vehicle (preceding vehicle) 4 starts to decelerate rapidly while the vehicle 1 is traveling on the travel path 7. At this time, the ECU 10 (the travel route control unit 10a) calculates a corrected travel route Rc. On the other hand, the ECU 10 (automatic collision prevention control unit 10b) calculates a predicted travel route Re. Since the preceding vehicle 4 is located on the predicted traveling route Re, there is a risk of a collision.

  If the vehicle 1 travels on the optimized corrected traveling route Rc, it does not collide with the preceding vehicle 4. However, when the vehicle 1 continues traveling on the predicted travel route Re and the TTC reaches the alarm generation time Ta (for example, 2 seconds), an alarm is generated, and then the TTC generates an automatic brake generation time Tth (for example, 1 second). Automatic brake is activated when it reaches.

  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 traveling route and the predicted traveling 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. In addition, when it is determined that the vehicle 1 deviates from the corrected traveling route, the alarm timing is advanced, so that the driver can execute the collision avoidance operation with a margin by the early alarm.

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

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

  Further, if the difference E is larger than the second threshold value Eth2 and the difference E tends to increase with time, it is considered that the vehicle 1 travels deviated from the predicted traveling route Rc. Therefore, in this case, the alarm generation time Ta is changed to a large value (for example, at most Ta = 2.4 seconds) according to the magnitude of the difference E (ie, as the difference is larger).

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

Next, with reference to FIG. 16, a detailed processing flow of the alarm occurrence time change process will be described.
The ECU (automatic collision prevention control unit 10b) repeatedly executes this processing flow every predetermined time (for example, every 0.1 seconds). 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 A predicted travel route is calculated (S61). Then, the ECU 10 determines whether an obstacle (for example, a preceding vehicle) is present on the predicted traveling route (S62).

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

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

  On the other hand, when the difference E is larger than the second threshold Rth2 (S64; Eth2 <E), the ECU 10 determines whether the difference E has increased temporally (S67). If the time fluctuation of the difference E tends to increase (S67; Yes), the ECU 10 advances the alarm timing according to the magnitude of the difference E (ie, the alarm time Ta is set to a large value).

  Furthermore, when the difference E is between the first threshold Eth1 and the second threshold Eth2 (S64; Yes), when the difference E is smaller than the first threshold Rth1 but temporally increases (S65; Yes), If the difference E is larger than the second threshold Rth2 but does not increase temporally (S67; No), the ECU 10 sets the alarm time Ta to a reference value (2 seconds) (S69) and ends the process. Do. The processing steps S65 and S67 may be omitted.

Next, the operation of the vehicle control device of the present embodiment will be described.
The present embodiment is a vehicle control device (ECU) 10 for avoiding a collision between a traveling route control unit 10a that repeatedly updates the target traveling route R of the vehicle 1 and an obstacle (for example, the preceding vehicle 4). And an automatic collision prevention control unit 10b that executes automatic collision prevention control processing (S14; S41 to S47). When an obstacle (preceding vehicle 4) is detected, the travel route control unit 10a is configured to calculate a target travel route Rc so as to avoid the obstacle (S13). The automatic collision prevention control unit 10b calculates the predicted traveling route Re based on the current traveling behavior of the vehicle 1 (S42), and the time to collision TTC with the obstacle (preceding vehicle 4) present on the predicted traveling route Re Is calculated (S43), and when this collision margin time TTC reaches a predetermined time (alarm occurrence 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 traveling route Rc and the predicted traveling route Re (alarm generation time changing process; S61 to S69).

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

  Specifically, in the present embodiment, when the difference E is less than the first threshold Eth1 (S64; E <Eth1), the automatic collision prevention control unit 10b delays the occurrence time of the alarm (S66). Thus, in the present embodiment, when the possibility of a 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 time (S68). As a result, in the present embodiment, when the possibility of a collision with an obstacle is high, it is possible to generate an alarm early to reliably avoid the collision.

  Furthermore, specifically, in the present embodiment, the difference E is the target position Pc of the vehicle 1 on the target travel route Rc for a predetermined time ahead, and the predicted position Pe of the vehicle 1 on the predicted travel route Re for a predetermined time 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 both ends 7 Runway 40 Speed distribution area a, b, c, d Equal relative speed line V _lim allowable upper limit Value 100 Vehicle control system D Width dimension D ₀ safe distance R target travel route R1 first travel route R2 second travel route R3 third travel route Rc1, Rc2, Rc3 corrected travel route X clearance

Claims (4)

A vehicle control device,
A travel route control unit that repeatedly updates a target travel route of the vehicle;
An anti-collision control unit that generates an alarm to avoid collision with an obstacle;
The traveling route control unit is configured to calculate the target traveling route so as to avoid the obstacle when an obstacle is detected.
The collision prevention control unit calculates a predicted traveling route based on the current traveling behavior of the vehicle, calculates a collision margin time with an obstacle present on the predicted traveling route, and the collision margin time is a predetermined time. Is configured to generate the alarm upon reaching
The vehicle control device, wherein the collision prevention control unit changes the occurrence timing of the alarm according to a difference between the target travel route and the predicted travel route.   The vehicle control device according to claim 1, wherein the collision prevention control unit delays the occurrence time of the alarm when the difference is less than a predetermined first threshold.   The vehicle control device according to claim 1, wherein the collision prevention control unit advances the timing of occurrence of the alarm when the difference exceeds a predetermined second threshold.   The difference according to claim 1, wherein the difference is a distance between a target position of the vehicle ahead of a predetermined time on the target travel route and a predicted position of the vehicle ahead of the predetermined time on the predicted travel route. The vehicle control device according to any one of the items.

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