JP6171976B2 - Vehicle behavior control device - Google Patents

Description

  The present invention relates to a vehicle behavior control apparatus that controls the behavior of a vehicle.

  Conventionally, automatic steering control is known in which a steering angle is automatically controlled by detecting a road boundary with a sensor such as a radar so that the vehicle travels along a curved road (for example, Patent Document 1). ).

  In the automatic steering control disclosed in Patent Document 1, the radius of curvature of a curved road is calculated from the distance to the road boundary ahead of the vehicle detected by the radar and the distance to the road boundary from the position offset to the left and right of the vehicle. Is calculated. Then, based on the calculated radius of curvature, the optimal distance from the vehicle tip to the road boundary located in front of the vehicle is calculated, and the actual distance from the vehicle tip to the road boundary located in front of the vehicle is calculated as the optimum distance. The steering angle of the vehicle is controlled to match the distance. In the automatic steering control disclosed in Patent Document 1, the steering angle is detected by a steering angle sensor, and the steering angle is changed in a direction approaching the target steering angle at a predetermined change speed.

  Further, Patent Document 2 discloses a vehicle state quantity such as a first yaw rate generated by automatic steering control and a steering angle of the driver at the time of switching from automatic steering control to driver steering according to driver steering. A behavior control device is disclosed that matches a vehicle state quantity such as a second yaw rate that should occur. Thus, the behavior control device disclosed in Patent Document 1 attempts to prevent the driver from feeling uncomfortable when switching from automatic steering control to driver steering.

Japanese Patent No. 4596063 JP 2012-232676 A

  As a case where the automatic steering control is switched to the driver steering, there is a case where the automatic steering control is switched because the automatic steering control cannot be maintained, in addition to the case where the switching is performed by the driver's intention. The case where the automatic steering control cannot be maintained may be a case where the detection by a sensor necessary for the automatic steering control, such as a radar that detects a road boundary or a rudder angle sensor that detects a steering angle of the host vehicle, has failed. .

  Switching from automatic steering control to driver steering due to failure of detection by sensors necessary for automatic steering control occurs at an unintended timing for the driver, so the driver is prepared to perform steering when switching to driver steering. Sometimes it is not possible. Therefore, in the behavior control device disclosed in Patent Document 2, when the detection by the sensor necessary for the automatic steering control fails and the driver steering is switched from the automatic steering control, the driver cannot immediately perform the steering operation. Your car may deviate from the road boundary.

  Further, in the behavior control device disclosed in Patent Document 2, the steering position at the time of switching from automatic steering control to driver steering is not necessarily a neutral position, and may be switched to the left or right from the neutral position. is there. Therefore, at the time of switching from automatic steering control to driver steering, there is a problem that it is difficult to determine the next steering operation such as whether the driver should switch back, increase or maintain steering.

  The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to prevent the vehicle from deviating from the road boundary when the automatic steering control is switched to the driver steering, and to the driver. An object of the present invention is to provide a vehicle behavior control device that makes it easy to determine the next steering operation.

  The vehicle behavior control device of the present invention is mounted on a vehicle, and a current position specifying unit (111) for sequentially specifying the current position of the host vehicle, and a road shape for sequentially determining the road shape of the road region in which the host vehicle is to travel. A determination unit (113) and an automatic steering control instruction unit (127) for performing automatic steering control for sequentially controlling the steering angle so that the host vehicle travels along the road shape sequentially determined by the road shape determination unit. A vehicle behavior control device (10) comprising: a vehicle speed specifying unit (142) that sequentially specifies a host vehicle speed that is the speed of the host vehicle; a current position of the host vehicle that is sequentially specified by a current position specifying unit; and a road shape A boundary distance calculation unit (114) for sequentially calculating the front road boundary distance from the own vehicle to the front road boundary located in front of the own vehicle based on the road shape sequentially determined by the determination unit, and used for automatic steering control Of the car's turning When the first failure determination unit (102) that determines whether or not the detection by the turning-related sensor that detects the alignment has failed and the first failure determination unit determines that the detection by the turning-related sensor has failed, An automatic steering control stopping unit (103) for stopping the automatic steering control, a forward road boundary distance sequentially calculated by the boundary distance calculating unit when the automatic steering control is stopped, and the own vehicle speed sequentially specified by the vehicle speed specifying unit The required turning angle change rate, which is the amount of change in the steering turning angle per hour, required to return the steering of the own vehicle to the neutral position before deviating from the front road boundary located in front of the own vehicle. A rate-of-change calculating unit (S442, S542) that sequentially calculates, a angle-of-change changing unit (S45, S55) that sequentially changes the steering angle of the vehicle according to the required angle-of-change change rate sequentially calculated by the rate-of-change calculating unit, When dynamic steering control is stopped, the vehicle deviates from the front road boundary located in front of the host vehicle based on the front road boundary distance sequentially calculated by the boundary distance calculation unit and the own vehicle speed sequentially specified by the vehicle speed specifying unit. A target deceleration calculation unit (S473) that sequentially calculates the target deceleration of the host vehicle for avoiding the braking, and a brake that sequentially controls the braking force of the host vehicle so that the deceleration of the host vehicle becomes the target deceleration A brake control instruction unit (S48) for performing control is provided.

  According to this, even when the detection by the turn-related sensor used for performing the automatic steering control fails and the automatic steering control is to be stopped, it is necessary to deviate from the front road boundary located in front of the host vehicle. The steering angle of the host vehicle is sequentially changed according to the required rate of change of the steering angle, which is the amount of change in the steering angle per hour required to return the steering of the host vehicle to the neutral position. Can be returned to position. By bringing the steering of the host vehicle close to the neutral position, it becomes easier for the driver to determine the next steering operation than when the steering is not brought close to the neutral position.

  The required turning angle change rate can be sequentially calculated from the integrated amount that changes the steering turning angle as long as the steering turning angle at the time when automatic steering control is stopped is known. Therefore, even if it becomes impossible to detect the steering angle after the stop point due to the effect of the detection by the turn-related sensor failing, the required turning angle change rate can be calculated sequentially. Therefore, even if the detection by the turn-related sensor fails and the automatic steering control is to be stopped, the steering of the own vehicle can be returned to the neutral position before deviating from the front road boundary located in front of the own vehicle. realizable.

  In addition, even if the detection by the turn-related sensor used for performing the automatic steering control fails and the automatic steering control is stopped, the deceleration of the own vehicle is the front road located in front of the own vehicle. Since the braking force of the host vehicle is sequentially controlled so as to achieve the target deceleration of the host vehicle so as not to deviate from the boundary, it is possible to prevent the host vehicle from deviating from the road boundary.

  In addition, when automatic steering control is stopped, if the steering of the own vehicle is simply returned to the neutral position, there is a problem that the own vehicle deviates from the road boundary in the case of a curved road. According to the vehicle behavior control device, it is possible to prevent the vehicle from deviating from the road boundary while returning the steering of the vehicle to the neutral position. Details are as follows.

  In the process of sequentially returning the steering angle to the neutral position according to the required turning angle change rate, the position of the front road boundary also changes, so the front road boundary distance also changes. On the other hand, according to the vehicle behavior control device of the present invention, the target deceleration calculation unit sequentially calculates the target deceleration from the forward road boundary distance and the own vehicle speed that change sequentially, and performs braking control. As the turning angle changes and the position of the front road boundary for the host vehicle changes, the braking control is performed so as not to deviate from the front road boundary.

  As a result, when the automatic steering control is switched to the driver steering, the vehicle can be prevented from deviating from the road boundary and the driver can easily determine the next steering operation.

  Another vehicle behavior control apparatus of the present invention is mounted on a vehicle and sequentially specifies a current position specifying unit (111) for sequentially specifying the current position of the own vehicle and a road shape of a road region where the own vehicle is to travel. A road shape determining unit (113) to be determined, and an automatic steering control instructing unit for performing automatic steering control for sequentially controlling the steering angle so that the vehicle travels along the road shape sequentially determined by the road shape determining unit ( 127) The vehicle behavior control device (10) includes a road shape determination unit using road shape determination information that can determine a road shape of a road area existing ahead of the own vehicle. Determines the road shape of the road area to be traveled, and determines whether or not acquisition of road shape determination information has failed, and a vehicle speed specifying unit (142) that sequentially specifies the vehicle speed that is the speed of the host vehicle Second failure determination unit (106 When the second failure determination unit determines that the acquisition of the road shape determination information has failed, the automatic steering control stopping unit (103a) for stopping the automatic steering control, and when the automatic steering control is stopped, Based on the road shape previously determined by the road shape determination unit, when the virtual road shape estimation unit (153) for estimating the virtual road shape following the road shape and automatic steering control are stopped, Based on the current position of the vehicle sequentially identified by the current position identifying unit and the virtual road shape estimated by the virtual road shape estimating unit, a virtual that is a virtual front road boundary located in front of the vehicle from the own vehicle A virtual boundary distance calculation unit (154) that calculates a virtual front road boundary distance to the front road boundary, a virtual front road boundary distance that is sequentially calculated by the virtual boundary distance calculation unit when automatic steering control is stopped, and a vehicle speed Sequential identification by specific part The amount of change in the steering angle per hour required to return the steering of the vehicle to the neutral position before deviating from the virtual front road boundary located in front of the vehicle based on the vehicle speed A change rate calculation unit (S652, S752) that sequentially calculates the turning angle change rate, and a turning angle change unit (S66) that sequentially changes the steering angle of the host vehicle according to the required turning angle change rate that is sequentially calculated by the change rate calculation unit. , S76), and when the automatic steering control is stopped, based on the virtual forward road boundary distance sequentially calculated by the virtual road boundary distance calculating unit and the own vehicle speed sequentially specified by the vehicle speed specifying unit, A target deceleration calculation unit (S683) for sequentially calculating the target deceleration of the host vehicle so as not to deviate from the virtual front road boundary located at the vehicle, and the host vehicle so that the deceleration of the host vehicle becomes the target deceleration. The braking force of the car And a brake control instructing unit (S69) for performing a brake control for the next control.

  According to this, even if the acquisition of road shape determination information that can determine the road shape of the road area where the host vehicle should travel fails and the automatic steering control is to be stopped, the front located in front of the host vehicle Because the vehicle's steering angle is changed sequentially according to the required angle change rate, which is the amount of change in the steering angle per hour, required to return the vehicle's steering to the neutral position before deviating from the road boundary. The steering of the vehicle can be returned to the neutral position. By bringing the steering of the host vehicle close to the neutral position, it becomes easier for the driver to determine the next steering operation than when the steering is not brought close to the neutral position.

  As an example of the case where acquisition of road shape determination information fails, the following can be cited as an example. When the detection result of the sensor used in the own vehicle is used as the road shape determination information, there is a case where the detection by the sensor fails. When road shape determination information is acquired by wireless communication from a preceding other vehicle or roadside machine, there is a case where this wireless communication fails.

  Even if acquisition of road shape determination information fails and automatic steering control is to be canceled, the virtual road shape following the road shape is estimated based on the road shape that has been determined so far. Then, the virtual front road boundary distance to the virtual front road boundary which is a virtual front road boundary is calculated. Then, the braking force of the host vehicle is sequentially controlled so that the deceleration of the host vehicle becomes the target deceleration of the host vehicle so as not to deviate from the virtual front road boundary located in front of the host vehicle. It is possible to prevent the car from deviating from the road boundary.

  Further, when the automatic steering control is stopped, if the steering of the own vehicle is simply returned to the neutral position, there is a problem that the own vehicle deviates from the road boundary in the case of a curved road. According to this vehicle behavior control apparatus, it is possible to prevent the own vehicle from deviating from the road boundary while returning the steering of the own vehicle to the neutral position. Details are as follows.

  In the process of sequentially returning the steering angle to the neutral position according to the required change rate of the turning angle, the position of the virtual front road boundary also changes, so the virtual front road boundary distance also changes. On the other hand, according to the vehicle behavior control device of the present invention, the target deceleration calculation unit sequentially calculates the target deceleration from the virtual forward road boundary distance and the own vehicle speed that change sequentially, and performs braking control. As the steering angle changes and the position of the virtual forward road boundary changes, the braking control is performed so as not to deviate from the virtual forward road boundary.

  As a result, when the automatic steering control is switched to the driver steering, the vehicle can be prevented from deviating from the road boundary and the driver can easily determine the next steering operation.

1 is a block diagram showing a schematic configuration of a driving support system 100. FIG. 2 is a functional block diagram illustrating an example of a schematic configuration of a vehicle control ECU 10 according to the first embodiment. FIG. 3 is a functional block diagram showing an example of a schematic configuration of an automatic steering control related processing unit 101. FIG. 5 is a flowchart illustrating an example of a flow of a first required angle calculation related process in an automatic steering control related processing unit 101. It is a mimetic diagram for explaining the 1st demand angle calculation related processing. 7 is a flowchart illustrating an example of a flow of second required angle calculation related processing in an automatic steering control related processing unit 101. 4 is a flowchart illustrating an example of a flow of behavior control related processing in an automatic steering control related processing unit 101. 3 is a functional block diagram illustrating an example of a schematic configuration of a cancellation related processing unit 104. FIG. 7 is a flowchart illustrating an example of a flow of processing related to cancellation in a processing unit related to cancellation in the first embodiment. 4 is a flowchart illustrating an example of a flow of processing related to initial required cut angle change rate calculation in the first embodiment. 6 is a flowchart illustrating an example of a flow of target deceleration calculation related processing in the first embodiment. 6 is a flowchart illustrating an example of a flow of a request cut angle change rate calculation related process in the first embodiment. It is a schematic diagram which shows the example which the own vehicle deviates from a road boundary by not returning the steering of the own vehicle to a neutral position. FIG. 5 is a schematic diagram showing changes in deviation margin time t, steering angle Θ, and own vehicle speed Vo from when automatic steering control is stopped to when the stop related processing is completed and the own vehicle stops. From to abort the automatic steering control to cancel time-related process is completed and the vehicle is stopped, a change in current value KdB _N and vehicle speed Vo of distance condition evaluation index, and shows the evaluation index KdB It is a schematic diagram. It is a schematic diagram which shows the example which the own vehicle deviates from a road boundary by rapidly returning the steering of the own vehicle to a neutral position. FIG. 6 is a schematic diagram for explaining an effect of the first embodiment. It is the schematic diagram which showed the change of the own vehicle speed Vo after stopping automatic steering control and starting a related process at the time of a stop until it transfers to driver steering. It is a functional block diagram which shows an example of the schematic structure of vehicle control ECU10 in Embodiment 2. FIG. It is a functional block diagram which shows an example of a schematic structure of the process part 104a at the time of cancellation. 10 is a flowchart illustrating an example of a flow of processing related to cancellation in a processing unit related to cancellation in a second embodiment. 10 is a flowchart illustrating an example of a flow of processing related to initial request cut angle change rate calculation in the second embodiment. 12 is a flowchart illustrating an example of a flow of target deceleration calculation related processing in the second embodiment. 10 is a flowchart illustrating an example of a flow of a request cut angle change rate calculation related process in the second embodiment. It is the schematic diagram which showed the change of the virtual departure margin time t_v, the steering angle (theta), and the own vehicle speed Vo after canceling automatic steering control until a related process at the time of cancellation is completed and the own vehicle stops. Changes in the virtual current value KdB _{N —} v of the approaching / separating state evaluation index and the own vehicle speed Vo, and the approaching / separating state evaluation from when the automatic steering control is stopped until the stop related processing is completed and the host vehicle stops. It is the schematic diagram which showed the parameter | index KdB. FIG. 10 is a schematic diagram for explaining the effect of the second embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiment shown below is an embodiment corresponding to an area where the left-hand traffic is legalized, and in the area where the right-hand traffic is legalized, the left and right are reversed from the following embodiments.

(Embodiment 1)
In the first embodiment, a case in which the vehicle behavior control device of the present invention is applied to the driving support system 100 will be described as an example. In FIG. 1, the whole structure of the driving assistance system 100 of Embodiment 1 is shown. As shown in FIG. 1, the driving support system 100 includes a VSC_ECU 1, a rudder angle sensor 2, a G sensor 3, a yaw rate sensor 4, an EPS_ECU 5, a distance measuring sensor 6, and a vehicle control ECU 10. The driving support system 100 is mounted on a vehicle.

<Schematic configuration of driving support system 100>
The VSC_ECU 1 controls a brake actuator (not shown) that applies a braking force to the host vehicle, and has a control function of VSC (Vehicle Stability Control (registered trademark)) that suppresses a side slip of the host vehicle. The VSC_ECU 1 receives information on the requested deceleration from the in-vehicle LAN, and controls the brake actuator so that the requested deceleration is generated in the host vehicle. Further, the VSC_ECU 1 transmits information on the vehicle speed Vo and the brake pressure to the in-vehicle LAN. VSC_ECU1 should just be set as the structure which acquires the own vehicle speed Vo from a wheel speed sensor etc., for example.

  The steering angle sensor 2 is a sensor that detects the steering angle of the host vehicle, and transmits the detected steering angle to the in-vehicle LAN. The G sensor 3 is an acceleration sensor that detects acceleration generated in the front-rear direction of the vehicle (that is, front-rear G) and acceleration generated in the left-right direction (that is, lateral G). Send to in-vehicle LAN. The yaw rate sensor 4 is a sensor that detects an angular velocity (that is, a yaw rate) around the vertical axis of the host vehicle, and transmits the detected yaw rate to the in-vehicle LAN. The steering angle sensor 2 and the yaw rate sensor 4 correspond to the turning-related sensors in the claims.

  The EPS_ECU 5 controls the steering angle (that is, the steering angle) by operating the EPS actuator 11. The EPS actuator 11 is a mechanism that changes the steering angle based on a command signal from the EPS_ECU 5, and includes, for example, a reduction gear that rotates integrally with the intermediate shaft and a motor that rotates the reduction gear.

  The distance measuring sensor 6 is a sensor that detects a boundary position of a road area that can be traveled and exists in front of the host vehicle. For example, the distance measuring sensor 6 may be configured to use a radar or a camera.

  When radar is used, a laser beam or millimeter wave is applied to a predetermined range in front of the host vehicle, the reflected light is received, and the road boundary of the road ahead of the host vehicle from the host vehicle (for example, a guardrail or curb) Detects the distance to obstacles on the road such as vehicles ahead. And vehicle control ECU10 detects the position with respect to the own vehicle of the said road boundary and an obstruction from the distance data of the said road boundary and obstruction obtained with the radar.

  The predetermined range ahead of the host vehicle may be a range extending to the left side or the right side of the host vehicle. Moreover, it is good also as a structure which provides multiple ranging sensors 6 so that a sensing direction may differ. Note that the distance measuring sensor 6 may be configured to detect the position of the road boundary or the obstacle with respect to the own vehicle.

  When using a camera, a known image recognition technique is used to detect road boundaries (for example, white lines, guardrails, curbs, etc.) of roads ahead of the vehicle with respect to the vehicle and obstacles on the road such as vehicles ahead. do it. The distance from the vehicle to the road boundary can be calculated from the target position in the captured image if the camera installation position and the optical axis direction are determined. And the position calculated from the target position in the captured image.

  The operation SW 9 is a switch group operated by the driver of the host vehicle, and operation information of the switch group is output to the vehicle control ECU 10.

  The vehicle control ECU 10 is mainly configured as a microcomputer, and each includes a known CPU, ROM, RAM, I / O, and a bus connecting them.

<Detailed Configuration of Vehicle Control ECU 10>
The vehicle control ECU 10 executes various processes based on various information input from the VSC_ECU 1, the steering angle sensor 2, the G sensor 3, the yaw rate sensor 4, the EPS_ECU 5, and the distance measuring sensor 6. The vehicle control ECU 10 corresponds to the vehicle behavior control device of the claims.

  As shown in FIG. 2, the vehicle control ECU 10 includes an automatic steering control related processing unit 101, a first failure determination unit 102, an automatic steering control stop unit 103, a stop related processing unit 104, and a manual steering start determination unit 105. ing.

<Detailed Configuration of Automatic Steering Control Related Processing Unit 101>
The automatic steering control related processing unit 101 performs processing related to automatic steering control for automatically controlling the steering angle so that the host vehicle travels along the curve of the curved road. As shown in FIG. 3, the automatic steering control related processing unit 101 includes a current position specifying unit 111, a boundary position detecting unit 112, a road outer shape determining unit 113, a road boundary distance calculating unit 114, a road width direction distance calculating unit 115, a curvature. A radius calculation unit 116, a road shape determination unit 117, a curve direction determination unit 118, a first cut angle calculation unit 119, a virtual boundary distance setting unit 120, a conversion unit 121, a position deviation calculation unit 122, a post-conversion position deviation calculation unit 123, A turning radius calculation unit 124, a second turning angle calculation unit 125, a target steering angle calculation unit 126, and a steering instruction unit 127 are provided.

  The current position specifying unit 111 performs current position specifying processing for sequentially specifying the current position of the host vehicle. As an example, in the current position specifying process, the vehicle position at a certain point in time is set as a starting point on two-dimensional coordinates, and the vehicle speed Vo sequentially acquired from the VSC_ECU 1 of the vehicle and the steering angle Θ acquired sequentially from the steering angle sensor 2 are also included. In addition, the current position of the vehicle is specified by sequentially calculating the current position of the vehicle on the two-dimensional coordinates. The current position of the own vehicle is, for example, the center of the front wheel axle of the own vehicle.

  The current position specifying unit 111 determines the current position of the vehicle based on information obtained from other sensors such as a receiver for a satellite positioning system that detects the current position of the vehicle based on radio waves from the satellite. It is good also as a structure to calculate.

  The boundary position detection unit 112 sequentially detects the road boundary and the position of the obstacle with respect to the current position of the vehicle from the road boundary and obstacle distance data obtained by the distance measuring sensor 6. As an example, the road boundary and the position of the obstacle may be configured to be represented as a position on the above-described two-dimensional coordinates.

  Based on the road boundary and the position of the obstacle detected by the boundary position detection unit 112, the road outer shape determination unit 113 sequentially determines the outer shape of the road area (hereinafter referred to as the road outer shape) on which the vehicle is to travel. The road outer shape determination unit 113 corresponds to the road shape determination unit in the claims.

  As an example, a travel route for traveling while avoiding road boundaries and obstacles detected by the boundary position detection unit 112 is generated on the aforementioned two-dimensional coordinates, and has a predetermined width from the center line of this route to the left and right. Determine the road outline. For example, a road outline having a boundary line having a width corresponding to a distance corresponding to a distance of 1.75 m on the left and right with the travel route as a center line may be determined.

  In addition, the automatic steering control related processing unit 101 includes a road boundary distance calculation unit 114, a road width direction distance calculation unit 115, a curvature radius calculation unit 116, a road shape determination unit 117, a curve direction determination unit 118, a first cut angle. A calculation unit 119, a virtual boundary distance setting unit 120, a conversion unit 121, a position deviation calculation unit 122, a post-conversion position deviation calculation unit 123, a turning radius calculation unit 124, a second turning angle calculation unit 125, a target steering angle calculation unit 126, The steering instruction unit 127 performs first required angle calculation related processing, second required angle calculation related processing, and behavior control related processing, which will be described later.

  In summary, in the first required angle calculation related processing, a curve turning required tire turning angle θ_curv for steering so that the distance from the host vehicle to the front road boundary located in front of the host vehicle is adjusted to an appropriate distance is calculated. In other words, the curve turning required tire turning angle θ_curv for steering the vehicle according to the curvature radius of the road outer shape is calculated. In the second required angle calculation related processing, a lane keep required tire turning angle θ_lane for adjusting the vehicle to the center of the road width of the road outline is calculated. In the behavior control-related processing, the vehicle turns to the road using the curve turning required tire turning angle θ_curv calculated in the first required angle calculation-related processing and the lane keep required tire turning angle θ_lane calculated in the second required angle calculation-related processing. The vehicle is adjusted to the center of the road width of the road outline while being steered according to the curvature radius of the outline.

<First request angle calculation related processing>
Here, the first required angle calculation related processing in the automatic steering control related processing unit 101 will be described using the flowchart shown in FIG. 4 and the schematic diagram of FIG. As described above, in the first required angle calculation related processing, the curve turning required tire turning angle θ_curv for steering the vehicle according to the curvature radius of the road outer shape is calculated. For example, the flowchart of FIG. 4 may be configured to start at regular intervals when a user operation indicating that the automatic steering control is started by the operation SW 9 is received. In the present embodiment, as an example, the fixed period is set to 100 msec.

  First, in step S1, the road boundary distance calculation unit 114 calculates the forward road boundary distance Dr from the current position of the host vehicle specified by the current position specifying unit 111 and the road outer shape determined by the road outer shape determination unit 113. . The road boundary distance calculation unit 114 corresponds to a boundary distance calculation unit in claims. The road boundary distance Dr is based on the vehicle's current position (that is, the front wheel axle center) on the tangent line drawn with respect to the road width centerline (hereinafter referred to as the road width centerline). To the front road boundary located in front of the host vehicle (see FIG. 5).

  In step S <b> 2, the road width direction distance calculating unit 115 calculates the road width direction distance L from the current position of the host vehicle specified by the current position specifying unit 111 and the road outer shape determined by the road outer shape determining unit 113. The road width direction distance L is the distance of the vehicle center in the road width direction with respect to one boundary of the road outer shape (see FIG. 5). The one boundary mentioned here is the front road boundary used when the front road boundary distance Dr is calculated in S1.

  In the flowchart of FIG. 4, the configuration in which the process of S <b> 2 is performed after the process of S <b> 1 is shown. For example, the order of the process of S1 and the process of S2 may be reversed, or the process of S1 and the process of S2 may be performed in parallel.

In step S3, the curvature radius calculation unit 116 calculates the curvature radius of the road width center line for the road outline located in front of the host vehicle from the forward road boundary distance Dr calculated in S1 and the road width direction distance L calculated in S2. The road width centerline curvature radius Ra is calculated (see FIG. 5). The road outline located in front of the vehicle mentioned here is the front road boundary used when the front road boundary distance Dr is calculated in S1. The road width centerline radius of curvature Ra is calculated by Expression 12 derived from Expressions 9 to 11 below.

  The road width centerline curvature radius Ra calculated in S3 is sequentially stored in the memory of the vehicle control ECU 10. Therefore, each time the flowchart of FIG. 4 is executed at regular intervals, the road width centerline curvature radius Ra is sequentially stored. The memory stores at least the road width centerline curvature radius Ra calculated by the new processing of S3 and the road width centerline curvature radius Ra calculated by the previous processing of S3 before the new processing of S3. Shall. For example, the storage in the memory may be configured to be erased when, for example, the ignition power of the own vehicle is turned off and the vehicle control ECU 10 is turned off.

  For example, as in the case where a straight road continues in front of the host vehicle, the front road boundary located in front of the host vehicle is not recognized for the road outer shape determined by the road outer shape determination unit 113, and the front road boundary distance Dr is calculated. If not, the road width centerline curvature radius Ra may be infinite or set to a sufficiently large value such as R10000 m.

  In step S4, the road shape determination unit 117 determines whether the road outline located in front of the host vehicle is a curved road or a straight road from the road width centerline curvature radius Ra calculated in S3. The road outline located in front of the vehicle mentioned here is the front road boundary used when the front road boundary distance Dr is calculated in S1.

  As an example, if the road width centerline curvature radius Ra calculated in S3 is greater than or equal to a preset threshold value, it is determined as a straight road, and if it is less than the threshold value, it is determined as a curved road. The threshold value may be a value of a radius of curvature that can be said to be a straight road, and may be, for example, R10000 m.

  In step S5, when it is determined in S4 that the front road boundary located in front of the host vehicle is a curved road (YES in S5), the process proceeds to step S7. On the other hand, if it is determined in S4 that the front road boundary located in front of the host vehicle is a straight road (NO in S5), the process proceeds to step S6, and the curve turning required tire turning angle θ_curv is assumed to be 0 in S6. The process of 4 is finished. In other words, when the vehicle is running on a straight road and is not close to a curved road, and steering according to the road width centerline curvature radius Ra is not necessary, steering according to the road width centerline curvature radius Ra is performed. I will not do it.

  In step S7, the curve direction determination unit 118 determines the curve direction of the front road boundary determined to be a curved road. As an example, if the front road boundary located in front of the vehicle is the left road boundary of the vehicle, it is determined as a right curve, and the front road boundary located in front of the vehicle is the right road boundary of the vehicle. If there is, it is determined as a left curve.

  In step S8, the first turning angle calculation unit 119 calculates a curve from the road width centerline curvature radius Ra calculated in S3, the curve direction determined in S7, and the wheelbase length WB of the own vehicle (see FIG. 5). The turning required tire turning angle θ_curv (see FIG. 5) is calculated, and the processing of FIG. 4 is terminated.

The curve turning required tire turning angle θ_curv is calculated by the following equation (13). The sgn (RL) in Equation 13 is 1 when the curve direction determined in S7 is a right curve, and is -1 when the curve direction is a left curve. The wheel base length WB of the host vehicle may be configured to use a value stored in advance in the memory of the vehicle control ECU 10.

<Second request angle calculation related processing>
Next, the second required angle calculation related processing in the automatic steering control related processing unit 101 will be described using the flowchart shown in FIG. As described above, in the second required angle calculation related processing, the lane keep required tire turning angle θ_lane for adjusting the own vehicle to the center of the road width of the road outline is calculated. The flowchart in FIG. 6 may be configured to be performed in parallel with the first request angle calculation related process, for example, at regular intervals.

  First, in step S21, as in step S1, the road boundary distance calculation unit 114 calculates the front road boundary distance Dr. In step S22, when the front road boundary distance Dr can be calculated (YES in S22), the process proceeds to step S24. On the other hand, for the road outline determined by the road outline determination unit 113, when the front road boundary located in front of the host vehicle is not recognized and the front road boundary distance Dr cannot be calculated (NO in S22), the process proceeds to step S23. Move.

  In step S23, the virtual boundary distance setting unit 120 sets a predetermined forward virtual boundary distance Dr_virtual as the forward road boundary distance Dr. This front virtual boundary distance Dr_virtual can be arbitrarily set, and may be about 50 m, for example.

  In step S <b> 24, the position deviation calculating unit 122 calculates the own vehicle lateral position deviation Δw from the current position of the own vehicle specified by the current position specifying unit 111 and the road outer shape determined by the road outer shape determining unit 113. The own vehicle lateral position deviation Δw is a position deviation of the own vehicle center in the road width direction with respect to the road width center line.

  In step S25, the conversion unit 121 performs a distance conversion process. In the distance conversion process, when the front road boundary distance Dr can be calculated in S21, a post-conversion boundary distance Dr ′ obtained by converting the front road boundary distance Dr into a value for the traveling direction of the host vehicle is calculated. Further, when the front virtual boundary distance Dr_virtual has been set in S23, a converted boundary distance Dr ′ obtained by converting the front virtual boundary distance Dr_virtual into a value in the traveling direction of the host vehicle is calculated.

The conversion from the forward road boundary distance Dr to the post-conversion boundary distance Dr ′ may be calculated using the following formulas 14 to 16. In Expression 14, an angle θw for correcting the vehicle lateral position deviation Δw is calculated from the front road boundary distance Dr calculated in S21 and the vehicle lateral position deviation Δw calculated in S24.

In Formula 15, the target travel for matching the traveling direction of the host vehicle and the own vehicle to the road width center line is calculated from the angle θw calculated in Formula 14 and the inclination θs of the traveling direction of the host vehicle with respect to the road width center line. The angle difference θws with respect to the direction is calculated. The inclination θs is calculated from the current position of the vehicle specified by the current position specifying unit 111 and the road outer shape determined by the road outer shape determining unit 113.

  In Expression 16, the converted boundary distance Dr is calculated from the angle difference θws calculated in Expression 15 and the distance Z that is the distance from the own vehicle to the road width center line of the virtual straight road at the position of the forward road boundary distance Dr. 'Is calculated. The distance Z is calculated from the current position of the host vehicle specified by the current position specifying unit 111 and the road outer shape determined by the road outer shape determining unit 113.

  The virtual straight road may be obtained by drawing a tangent to the road boundary of the road outline with reference to the front wheel axle position of the own vehicle. For example, the distance Z may be a distance from the front wheel axle center of the host vehicle to the intersection of the road width center line of the virtual straight road and the road boundary of the road outline determined by the road outline determination unit 113.

The distance Z is a virtual distance from the vehicle to the road width center line at the position of the virtual boundary distance Dr_virtual when the virtual boundary distance Dr_virtual is set in S23. For example, the distance Z may be a distance from the center of the front wheel axle of the host vehicle to a virtual boundary distance Dr_virtual on the road width center line of the road outline determined by the road outline determination process.

In addition, the conversion from the virtual boundary distance Dr_virtual to the post-conversion boundary distance Dr ′ may be calculated using the following Expression 17 and Expressions 15 and 16 described above. In Expression 17, an angle θw for correcting the vehicle lateral position deviation Δw is calculated from the virtual boundary distance Dr_virtual set in S23 and the vehicle lateral position deviation Δw calculated in S24.

  In step S26, the post-conversion position deviation calculation unit 123 calculates a post-conversion position deviation Δw ′ obtained by converting the own vehicle lateral position deviation Δw into a value in the traveling direction of the own vehicle. The conversion from the vehicle lateral position deviation Δw to the post-conversion position deviation Δw ′ may be calculated using the following Equation 18.

In Expression 18, when the front road boundary distance Dr can be calculated in S21, the converted position deviation Δw ′ is calculated from the angle difference θws calculated using Expressions 14 and 15 and the distance Z described above. . If the virtual boundary distance Dr_virtual has been set in S23, the post-conversion position deviation Δw ′ is calculated from the angle difference θws calculated using the equations 17 and 15 and the distance Z described above.

  In addition, the process of S25 and the process of S26 may be reverse order, and it is good also as a structure performed in parallel.

In step S27, the turning radius calculation unit 124 uses the post-conversion boundary distance Dr ′ calculated in S25 and the post-conversion position deviation Δw ′ calculated in S26 to adjust the vehicle to the road width center line. A simple turning radius Rw is calculated. The turning radius Rw is calculated by Expression 21 derived from Expressions 19 to 20 below.

  In step S28, the second turning angle calculation unit 125 calculates the lane-keep required tire turning angle θ_lane based on the turning radius Rw calculated in S27, the wheelbase length WB of the host vehicle, and the aforementioned angle difference θws. Then, the process of FIG.

The lane keep request tire turning angle θ_lane is calculated by the following Expression 22. The sgn (θws) in Expression 22 is 1 when the angle difference θws is a positive value, and is −1 when the angle difference θws is a negative value. The wheel base length of the host vehicle may be configured to use a value stored in advance in the memory of the vehicle control ECU 10.

<Behavior control related processing>
Next, behavior control related processing in the automatic steering control related processing unit 101 will be described using the flowchart shown in FIG. As described above, the behavior control related process uses the curve turning required tire turning angle θ_curv calculated in the first required angle calculation related processing and the lane keep required tire turning angle θ_lane calculated in the second required angle calculation related processing. The vehicle is adjusted to the center of the road width of the road outline while the vehicle is steered according to the radius of curvature of the road outline. The flowchart of FIG. 7 is performed every time the curve turning required tire turning angle θ_curv and the lane keep requesting tire turning angle θ_lane are newly calculated by, for example, the first required angle calculation related processing and the second required angle calculation related processing. And it is sufficient.

  In step S31, the target steering angle calculation unit 126 calculates the curve turning required tire turning angle θ_curv calculated in the first required angle calculation related processing and the lane keep required tire turning angle θ_lane calculated in the second required angle calculation related processing. From this, a target steering angle Θ (hereinafter, target steering angle Θ) is calculated. The target steering angle Θ is a steering angle Θ for adjusting the vehicle to the center of the road width of the road outline while steering the vehicle according to the curvature radius of the road outline.

The target steering angle Θ is calculated using the following formulas 23 and 24. First, as shown in Equation 23, the curve turning required tire turning angle θ_curv calculated in the first required angle calculation related processing and the lane keep required tire cutting angle θ_lane calculated in the second required angle calculation related processing are added. In addition, the required tire turning angle θ is calculated.

Subsequently, the target steering angle Θ is calculated from the required tire turning angle θ using Equation 24. N in Expression 24 is a ratio (constant) between the steering angle (that is, the steering angle) Θ and the tire turning angle θ.

  In step S32, the steering instruction unit 127 transmits the target steering angle Θ calculated in S31 to the EPS_ECU 5, thereby matching the steering angle of the host vehicle with the target steering angle Θ, and the process of FIG. Receiving the target steering angle Θ, the EPS_ECU 5 controls the EPS actuator 11 while detecting the steering angle by the steering angle sensor 2, and changes the steering angle in a direction approaching the target steering angle Θ at a predetermined change speed. I do. Therefore, the steering instruction unit 127 corresponds to the automatic steering control instruction unit in the claims.

<Cancellation of Automatic Steering Control in Embodiment 1>
Returning to FIG. 2, the cancellation of the automatic steering control will be described. The first failure determination unit 102 monitors the output value from the rudder angle sensor 2 used for automatic steering control in the EPS_ECU 5, and when the output value from the rudder angle sensor 2 is not obtained for a predetermined time or more, or this output When the value is abnormal, it is determined that the detection by the rudder angle sensor 2 has failed. The predetermined time here may be, for example, a time exceeding the detection cycle of the rudder angle sensor 2. Further, the output value of the rudder angle sensor 2 may be abnormal, for example, when the output value changes abruptly to such an extent that continuity with past values is not recognized.

  When the first failure determination unit 102 determines that the detection by the steering angle sensor 2 has failed, the automatic steering control stop unit 103 stops the automatic steering control by the EPS_ECU 5. Further, the automatic steering control stop unit 103 stops the first required angle calculation related processing, the second required angle calculation related processing, and the behavior control related processing in the automatic steering control related processing unit 101. Further, when the automatic steering control is stopped, the automatic steering control stopping unit 103 notifies the stop related processing unit 104 that the automatic steering control is stopped.

<Detailed Configuration of Cancellation Related Processing Unit 104 in Embodiment 1>
Here, the cancellation related processing unit 104 will be described. The suspension related processing unit 104 performs deceleration control so that the own vehicle does not deviate from the road boundary during the transition period from when the automatic steering control is stopped until the driver starts the steering operation. Performs processing related to canceling to return to the neutral position. As shown in FIG. 8, a steering angle acquisition unit 141, a vehicle speed identification unit 142, a road boundary distance acquisition unit 143, a departure margin time calculation unit 144, a change rate calculation unit 145, a turning angle change unit 146, an evaluation index calculation unit 147, A target value setting unit 148, a target relative speed calculation unit 149, a target deceleration calculation unit 150, a braking control instruction unit 151, and a steering angle estimation unit 152 are provided.

<Cancellation related process in Embodiment 1>
Next, the suspension related processing in the suspension related processing unit 104 will be described with reference to the flowcharts of FIGS. FIG. 9 is a flowchart illustrating an example of the flow of processing related to cancellation in the first embodiment, and FIGS. 10 to 12 are flowcharts illustrating an example of the flow of subroutine in the processing related to cancellation in the first embodiment. The flowchart in FIG. 9 may be configured to start when the suspension related processing unit 104 receives a notification from the automatic steering control cancellation unit 103 to cancel the automatic steering control.

First, in step S <b> 41, the steering angle acquisition unit 141 acquires the steering angle Θ ₀ (that is, the steering turning angle Θ ₀ ) of the host vehicle at the time when automatic steering control is stopped from the steering angle sensor 2. In step S42, the vehicle speed identification unit 142 obtains the vehicle speed Vo ₀ in stop time of the automatic steering control from VSC_ECU1. At step S43, road boundary distance acquisition section 143 acquires the forward road boundary distance Dr ₀ at stop time of the automatic steering control from the road boundary distance calculation unit 114.

In S41 to S43, the time stamp may be used to specify and acquire the steering angle Θ ₀ , the host vehicle speed Vo ₀ , and the forward road boundary distance Dr ₀ at the time when automatic steering control is stopped. The calculated value may be acquired by specifying the steering angle Θ ₀ , the host vehicle speed Vo ₀ , and the forward road boundary distance Dr ₀ at the time when automatic steering control is stopped. Moreover, the process of S41-S43 is good also as a structure performed in parallel, and good also as a structure which replaced the order of the process. Hereinafter, the steering angle Θ ₀ , the host vehicle speed Vo ₀ , and the front road boundary distance Dr ₀ at the time when automatic steering control is stopped are referred to as the initial steering angle Θ ₀ , the initial host vehicle speed Vo ₀ , and the initial front road boundary distance Dr ₀ .

  In step S44, an initial required cut angle change rate calculation related process is performed. Here, an outline of the processing related to the initial required turning angle change rate calculation will be described using the flowchart of FIG. In the processing related to the calculation of the initial required turning angle change rate, the amount of change in steering angle per hour required to return the steering of the vehicle to the neutral position before the vehicle deviates from the front road boundary located in front of the vehicle. Is calculated.

In step S441, the departure allowance time calculation unit 144 determines that the automatic steering control is stopped according to the following equation 1 from the initial own vehicle speed Vo ₀ acquired in S42 and the initial forward road boundary distance Dr ₀ acquired in S43. A departure grace time t ₀ until the vehicle departs from the road boundary is calculated. This S441 corresponds to the deviation grace time calculation unit in the claims. Hereinafter, the departure grace time t ₀ at the time when automatic steering control is stopped is referred to as an initial departure grace time t ₀ .

In step S442, change rate calculating section 145, an initial departure grace time t ₀ calculated in S441, from the acquired initial steering angle theta ₀ Prefecture in S41, according to Equation 3 below, requests cutting the stopped time of the automatic steering control The angle change rate ΔΘ ₀ is calculated. This S442 corresponds to a change rate calculation unit in the claims. The required turning angle change rate ΔΘ ₀ is the amount of change per hour in the steering angle required to return the steering of the vehicle to the neutral position before the vehicle deviates from the front road boundary located in front of the vehicle. . Hereinafter, the required turning angle change rate ΔΘ ₀ when automatic steering control is stopped is referred to as an initial required turning angle change rate ΔΘ ₀ .

Returning to FIG. 9, in step S45 following S44, the turning angle changing unit 146 transmits the amount of change in the steering angle per time to the EPS_ECU ₅ according to the initial required turning angle change rate ΔΘ ₀ calculated in S44. The operation of returning the steering of the own vehicle to the neutral position is started. This S45 corresponds to the cut angle changing portion in the claims.

As an example, when the control period of the stop-related process is 100 msec, the turning angle changing unit 146 transmits the amount of change in the steering angle per 100 msec to the EPS_ECU ₅ according to the initial required turning angle change rate ΔΘ _0. . The EPS_ECU 5 that has received the change amount of the steering angle per control cycle of 100 msec, for example, changes the steering angle by an angle corresponding to the received change amount by sequentially changing the steering angle at a constant speed during 100 msec.

In step S46, the evaluation index calculation unit 147 approaches and separates the automatic steering control from the initial vehicle speed Vo ₀ acquired in S42 and the initial forward road boundary distance Dr ₀ acquired in S43 according to the following equation 25. to calculate the value KdB ₀ of state evaluation index. Hereinafter, the approaching / separating state evaluation index value KdB ₀ at the time when automatic steering control is stopped is referred to as an initial value KdB ₀ .

  Here, the approach / separation state evaluation index KdB will be described. The approaching / separating state evaluation index KdB (see Japanese Patent No. 4645598) is an index that represents the approaching / separating state with respect to an object in consideration of the speed at which the own vehicle approaches the object. Is an index that increases as the speed of approaching the object increases and increases with increasing distance to the object becomes steeper as the distance to the object decreases. It has already been recognized by academic societies and the like that when speed control is performed using the approaching / separating state evaluation index KdB, the driver can perform speed control without a sense of incongruity.

  In the stop related processing, deceleration control is performed using the approach / separation state evaluation index KdB so that the vehicle does not deviate from the road boundary, and the vehicle driver performs deceleration that does not cause a sense of incongruity.

  In step S47, target deceleration calculation related processing is performed. Here, an outline of the target deceleration calculation-related processing will be described using the flowchart of FIG. In the target deceleration calculation related processing, the target deceleration is calculated so as to prevent the driver from deviating from the road boundary and to perform deceleration without causing a sense of incongruity for the driver of the host vehicle.

In step S471, the target value setting unit 148 uses the initial forward road boundary distance Dr ₀ acquired in S43, the initial value KdB _{0 of} the approaching / separating state evaluation index calculated in S46, and the current forward road boundary distance Dr _N as follows: The target value KdB_t of the approaching / separating state evaluation index determined according to Equation 26 is set. The current forward road boundary distance Dr _N may be obtained from the road boundary distance calculation unit 114. Further, when the flowchart of FIG. 9 is looped and the process is repeated, a configuration using the latest forward road boundary distance Dr _N acquired in step S53 described later may be used.

In step S472, the target relative speed calculation unit 149 calculates a target relative speed Vr_t corresponding to the target value KdB_t of the approaching / separating state evaluation index set in S471 according to the following Expression 27. The target relative speed Vr_t is a relative speed targeted by the host vehicle with respect to the front road boundary located in front of the host vehicle. Since the front road boundary is fixed and the speed is 0, the target relative speed Vr_t is substantially the target speed of the host vehicle.

In step S473, the target deceleration calculating unit 150 calculates the target relative speed Vr_t calculated in S472 and the current relative speed Vr_p of the host vehicle with respect to the front road boundary located in front of the host vehicle according to the following equation 28. The deceleration Gd is calculated. This S473 corresponds to a target deceleration calculation unit in the claims. Since the front road boundary is fixed and the speed is 0, the current host vehicle speed Vo _N acquired from the VSC_ECU 1 by the vehicle speed specifying unit 142 is used as the current relative speed Vr_p. Ta in Equation 28 is a predetermined time set in advance.

  Returning to FIG. 9, in step S48 subsequent to S47, the braking control instruction unit 151 generates a braking force such that the actual deceleration detected by the G sensor 3 becomes the target deceleration Gd calculated in step S473. The VSC_ECU 1 is instructed so that This S48 corresponds to the braking control instruction section in the claims. The VSC_ECU 1 performs a braking control that generates a braking force in response to the instruction.

  The braking force may be generated by controlling a brake actuator, or an engine brake may be used. In addition, the braking force instructed from the braking control instruction unit 151 to the VSC_ECU 1 may be determined from a map that defines the relationship between the target deceleration Gd and the braking force, for example.

  In step S49, when the termination-related process termination condition is satisfied (YES in S49), the instruction from the braking control instruction unit 151 to VSC_ECU1 is terminated, and the termination-related process is terminated. On the other hand, when the termination related process termination condition is not satisfied (NO in S49), the process proceeds to step S50.

As an example of when the termination-related process termination condition is satisfied, when the target relative speed Vr_t becomes a predetermined speed (1 km / h) or less, or when the current host vehicle speed Vo _N is substantially zero and There are cases where a stop of a car is detected. Furthermore, the steering operation of the own vehicle may be started by the user.

  The manual steering start determination unit 105 determines whether or not the steering operation of the host vehicle has been started by the user. In the manual steering start determination unit 105, as an example, when the difference between the change amount of the steering angle requested by the turning angle change unit 146 and the actual change amount of the steering angle is equal to or greater than a threshold value, The manual steering start determination unit 105 may determine that the steering operation has started. In addition, when an external force applied to the steering is detected by a sensor provided in the steering, the manual steering start determination unit 105 may determine that the user has started the steering operation of the host vehicle.

  The processing from S44 to S45 and the processing from S46 to S48 may be performed in parallel, or the order may be switched.

  In step S50, when it becomes the control cycle of the related process at the time of cancellation (YES in S50), the process proceeds to step S51. On the other hand, if the control cycle is not reached (NO in S50), the process returns to S49 and the process is repeated.

In step S51, the steering angle estimation unit 152 estimates the current steering angle Θ _N (that is, the steering turning angle Θ _N ). The steering angle estimation unit 152 is configured to estimate the current steering angle Θ _N from the initial steering angle Θ ₀ acquired in S41 and a value obtained by integrating the amount of change of the steering angle requested by the turning angle changing unit 146. That's fine. This S51 corresponds to a cut angle estimation unit.

In step S52, the vehicle speed identification unit 142 acquires the current vehicle speed Vo _N from VSC_ECU1. In step S <b> 53, the road boundary distance acquisition unit 143 acquires the current forward road boundary distance Dr _N from the road boundary distance calculation unit 114. The processing of S51 to S53 may be performed in parallel, or the processing order may be changed.

In step S54, a required cut angle change rate calculation related process is performed. Here, an outline of the request cut angle change rate calculation related process will be described using the flowchart of FIG. In the required turning angle change rate calculation-related processing, the required turning angle change rate ΔΘ _N after the time point when the automatic steering control is stopped is calculated.

In step S541, the departure allowance time calculation unit 144 calculates the current departure allowance time t _N according to the following equation 2 from the host vehicle speed Vo _N acquired in S52 and the forward road boundary distance Dr _N acquired in S53. . This S541 also corresponds to the departure grace time calculation unit in the claims.

In step S542, the change rate calculation unit 145 determines the current required turning angle change rate ΔΘ _N according to the following equation 4 from the deviation postponement time t _N calculated in S541 and the current steering angle Θ _N estimated in S51. Is calculated. This S542 also corresponds to the change rate calculation unit in the claims.

Returning to FIG. 9, in step S55 following S54, the turning angle changing unit 146 transmits the amount of change in the steering angle per time to the EPS_ECU 5 in accordance with the required turning angle change rate ΔΘ _N calculated in S55. The operation of returning the car steering to the neutral position is continued. This S55 also corresponds to the cutting angle changing portion in the claims.

  In the stop related processing, the value of the road boundary distance Dr is appropriately offset (for example, by subtracting 1 m, etc.), so that when the stop related processing is completed and the own vehicle stops, the center of the front axle is set as the vehicle position. It is preferable not only to prevent the vehicle from deviating from the road boundary, but also to prevent the entire vehicle body from protruding from the road boundary.

<Summary of Embodiment 1>
For example, when detection by the steering angle sensor 2 of the own vehicle fails during traveling on a curved road and automatic steering control is to be stopped, the steering of the own vehicle must be returned to the neutral position as shown in FIG. As such, the vehicle deviates from the road boundary.

  A to E in FIG. 13 indicate steering positions. FIG. 13A shows that the vehicle is steered until the tire turning angle that maintains the above-mentioned road width direction distance L is reached. FIG. 13B shows a state in which the vehicle is steered until the tire turning angle that maintains the road width direction distance L is reached. FIGS. 13C to 13E show a state where the steering is not returned to the neutral position while being steered until the tire turning angle that maintains the road width direction distance L is reached.

  On the other hand, according to the configuration of the first embodiment, even when detection by the rudder angle sensor 2 fails and automatic steering control is to be stopped, the vehicle departs from the front road boundary located in front of the host vehicle. As shown in FIG. 14, according to the required turning angle change rate ΔΘ, which is the amount of change per hour of the steering angle Θ (that is, the steering turning angle Θ) required to return the vehicle's steering to the neutral position by The steering angle Θ of the own vehicle is sequentially changed.

FIG. 14 is a diagram illustrating changes in the departure allowance time t, the steering angle Θ, and the host vehicle speed Vo from when the automatic steering control is stopped to when the stop related processing is completed and the host vehicle stops. In FIG. 14, when the automatic steering control is stopped, that is, when the front road boundary distance Dr is at the initial front road boundary distance Dr ₀ , the front road boundary distance Dr is at Dr ₁ , Dr ₂ , Dr _N. Shows about. Also, O ₀ ~ O _E in FIG. 14, stop time related processing is completed and the vehicle is shown each front road boundary to a stop after stop the automatic steering control.

  According to the configuration of the first embodiment, as shown in FIG. 14, the steering of the host vehicle can be returned to the neutral position before deviating from the front road boundary. Therefore, avoiding a situation in which the vehicle deviates from the road boundary when detection by the steering angle sensor 2 of the own vehicle fails during traveling on a curved road and automatic steering control is to be stopped. Is possible. Further, by bringing the steering of the host vehicle closer to the neutral position, it becomes easier for the driver to determine the next steering operation than when the steering is not brought closer to the neutral position.

  Furthermore, according to the configuration of the first embodiment, when detection by the rudder angle sensor 2 fails and automatic steering control is to be stopped, as shown in FIG. 15, the target value of the approach / separation state evaluation index Using KdB_t, the braking force of the host vehicle is sequentially controlled so that the deceleration of the host vehicle becomes the target deceleration Gd of the host vehicle so as not to deviate from the front road boundary located in front of the host vehicle. It will be.

15, from the to cancel the automatic steering control to cancel time-related process is completed and the vehicle is stopped, a change in current value KdB _N and vehicle speed Vo of distance condition evaluation index, and distance condition evaluation It is the figure which showed the parameter | index KdB.

In FIG. 15, when the automatic steering control is stopped, that is, when the front road boundary distance Dr is at the initial front road boundary distance Dr ₀ , the front road boundary distance Dr is at Dr ₁ , Dr ₂ , Dr _N. Shows about. O ₀ ~ O _E in Figure 15, stop time related processing is completed and the vehicle is shown each front road boundary to a stop after stop the automatic steering control. Further, in FIG. 15, as an example, the target value KdB_t of the approaching / separating state evaluation index when automatic steering control is stopped is shown.

  According to the configuration of the first embodiment, it becomes possible to prevent the own vehicle from deviating from the road boundary, and the deceleration control is performed using the approach / separation state evaluation index KdB. It is possible to perform no deceleration.

  In addition, when detection by the steering angle sensor 2 of the own vehicle fails during traveling on a curved road and automatic steering control is to be stopped, simply returning the steering of the own vehicle to the neutral position As shown in FIG. 16, the own vehicle deviates from the road boundary.

  16A to 16C show steering positions. FIG. 16A shows that the vehicle is steered until the tire turning angle that maintains the above-mentioned road width direction distance L is reached. B of FIG. 16 shows a state in which the steering is suddenly returned to the neutral position from the state where the steering is performed until the tire turning angle that maintains the road width direction distance L is reached. FIG. 16C shows a state in which the steering is held at the neutral position.

  On the other hand, according to the configuration of the first embodiment, it is possible to prevent the own vehicle from deviating from the road boundary while returning the steering of the own vehicle to the neutral position. Details will be described below with reference to FIG. FIG. 17A shows that the vehicle is steered until the tire turning angle that maintains the distance L in the road width direction is reached. FIG. 17B shows a state in which the vehicle is steered until the tire turning angle that maintains the road width direction distance L is reached. FIGS. 17C to 17D show a state in which the steering is returned to the neutral position. E in FIG. 17 shows a state in which the steering is returned to the neutral position.

  In the process of sequentially returning the steering angle Θ to the neutral position according to the required turning angle change rate ΔΘ (see B to D in FIG. 17), the position of the front road boundary also changes, so the front road boundary distance Dr also changes. Go. On the other hand, according to the first embodiment, the target deceleration Gd is sequentially calculated from the forward road boundary distance Dr and the own vehicle speed Vo that are sequentially changed, and the braking control is performed. As the position of the front road boundary changes, braking control is performed so as not to deviate from the front road boundary. As a result, it is possible to prevent the vehicle from deviating from the road boundary while returning the steering of the vehicle to the neutral position (see E in FIG. 17).

  Further, according to the configuration of the first embodiment, when the manual steering start determination unit 105 determines that the steering operation of the host vehicle has been started by the user, the instruction from the braking control instruction unit 151 to the VSC_ECU 1 is terminated, and The braking control at is terminated. In other words, the automatic braking is terminated. Therefore, automatic braking different from the driver's intention is stopped, and it is possible to smoothly shift to acceleration / deceleration and steering operation by the driver's brake operation. Details will be described below with reference to FIG.

  FIG. 18 is a diagram illustrating a change in the host vehicle speed Vo from when the automatic steering control is stopped and the related processing at the time of cancellation is started until the driver steering is started. In the graph showing the change in the own vehicle speed Vo in FIG. 18, the solid line shows the actual change in the own vehicle speed Vo, and the dotted line shows the change in the own vehicle speed Vo by the automatic braking control by the stop related processing.

  FIG. 18A shows that the vehicle is steered until the tire turning angle that maintains the above-mentioned road width direction distance L is reached. FIG. 18B shows a state in which the vehicle is steered until the tire turning angle that maintains the road width direction distance L is reached. FIG. 18C shows a state in which the driver has performed the steering operation and started steering the host vehicle. 17A to 17E show a state where the driver is performing a steering operation.

As shown in FIG. 18, when the driver performs the steering operation and starts to steer the own vehicle (at the time of the front road boundary distance Dr _{2 in} FIG. 18), it is not a change in the own vehicle speed Vo due to automatic braking control. The vehicle speed Vo is changed by the driver's brake operation.

(Embodiment 2)
The present invention is not limited to the above-described first embodiment, and the following second embodiment is also included in the technical scope of the present invention. Hereinafter, Embodiment 2 will be described with reference to the drawings. For convenience of explanation, members having the same functions as those shown in the drawings used in the description of Embodiment 1 are given the same reference numerals, and descriptions thereof are omitted.

  The driving support system 100 according to the second embodiment is the same as the driving support system 100 according to the first embodiment except that the conditions for stopping the automatic steering control are different and a part of the related processing at the time of stopping the vehicle is different.

<Detailed Configuration of Vehicle Control ECU 10 in Embodiment 2>
The vehicle control ECU 10 executes various processes based on various information input from the VSC_ECU 1, the steering angle sensor 2, the G sensor 3, the yaw rate sensor 4, the EPS_ECU 5, and the distance measuring sensor 6.

  As shown in FIG. 19, the vehicle control ECU 10 includes an automatic steering control related processing unit 101, a second failure determination unit 106, an automatic steering control stop unit 103a, a stop related processing unit 104a, and a manual steering start determination unit 105. ing. Since the first required angle calculation related process, the second required angle calculation related process, and the behavior control related process in the automatic steering control related processing unit 101 are the same as those in the first embodiment, description thereof will be omitted.

<About Canceling Automatic Steering Control in Embodiment 2>
The second failure determination unit 106 fails in the detection by the distance measuring sensor 6 when the detection result of the distance measuring sensor 6 is not obtained for a predetermined time or longer by the boundary position detection unit 112 of the automatic steering control related processing unit 101. Is determined. The predetermined time mentioned here may be, for example, a time exceeding the detection cycle of the distance measuring sensor 6.

  Then, the automatic steering control stopping unit 103a stops the automatic steering control in the EPS_ECU 5 when the second failure determination unit 106 determines that the detection by the distance measuring sensor 6 has failed. In addition, the automatic steering control stop unit 103a stops the first required angle calculation related processing, the second required angle calculation related processing, and the behavior control related processing in the automatic steering control related processing unit 101. Furthermore, when the automatic steering control is stopped, the automatic steering control stop unit 103a notifies the stop related processing unit 104a that the automatic steering control is stopped.

<Detailed Configuration of Cancellation Related Processing Unit 104a in Embodiment 2>
Here, the cancellation related processing unit 104a will be described. The suspension-related processing unit 104a performs deceleration control so that the host vehicle does not deviate from the road boundary during the transition period from when the automatic steering control is stopped until the driver starts steering operation. Performs processing related to canceling to return to the neutral position.

  As shown in FIG. 20, a steering angle acquisition unit 141, a vehicle speed specification unit 142, a road boundary distance acquisition unit 143, a departure allowance time calculation unit 144, a change rate calculation unit 145, a turning angle change unit 146, an evaluation index calculation unit 147, A target value setting unit 148, a target relative speed calculation unit 149, a target deceleration calculation unit 150, a braking control instruction unit 151, a virtual road outer shape estimation unit 153, and a virtual road boundary distance calculation unit 154 are provided.

<Cancellation Related Process in Embodiment 2>
Next, the suspension related processing in the suspension related processing unit 104a will be described with reference to the flowcharts of FIGS. FIG. 21 is a flowchart illustrating an example of the flow of processing related to cancellation in the second embodiment, and FIGS. 22 to 24 are flowcharts illustrating an example of the flow of a subroutine in processing related to cancellation in the second embodiment. The flowchart in FIG. 21 may be configured to start when the suspension-related processing unit 104a receives a notification to cancel the automatic steering control from the automatic steering control cancellation unit 103a.

  First, the processing from step S61 to step S62 is the same as the processing from S41 to S42 in the first embodiment. In step S63, the virtual road outline estimating unit 153 calculates a virtual road outline (hereinafter referred to as a virtual road outline) following the road outline based on the road outline determined so far by the road outline determining unit 113. presume. As an example, a curve with a constant curve R, which is the same as the end portion of the road outline that has been determined by the road outline determination unit 113 so far, is defined as the virtual road outline.

  In step S64, the virtual road boundary distance calculation unit 154 calculates a virtual front road boundary distance from the current position of the vehicle specified by the current position specifying unit 111 and the virtual road outer shape estimated by the virtual road outer shape estimation unit 153. (Hereinafter, virtual front road boundary distance) Dr_v is calculated. The virtual front road boundary distance Dr_v is a tangent line drawn with respect to the center line of the road width of the virtual road outline (hereinafter referred to as the virtual road width center line) on the basis of the current position of the own vehicle (that is, the front axle center). The distance from the vehicle to a virtual forward road boundary (hereinafter referred to as a virtual forward road boundary) located in front of the vehicle.

Hereinafter, the virtual forward road boundary distance Dr ₀ _v at the time when automatic steering control is stopped is referred to as an initial virtual forward road boundary distance Dr ₀ _v.

  In step S65, an initial virtual request cut angle change rate calculation related process is performed. Here, an outline of the process related to the calculation of the initial virtual required cut angle change rate will be described using the flowchart of FIG. In the processing related to the calculation of the initial virtual required turning angle change rate, the steering angle per hour required for returning the steering of the vehicle to the neutral position before the vehicle deviates from the virtual front road boundary located in front of the vehicle. The amount of change is calculated.

In step S651, the departure allowance time calculation unit 144 determines whether the automatic steering control is stopped according to the following equation 5 from the initial host vehicle speed Vo ₀ acquired in S62 and the initial virtual forward road boundary distance Dr ₀ _v calculated in S64. The virtual departure grace time t ₀ _v until the vehicle deviates from the virtual front road boundary is calculated. This S651 corresponds to the virtual departure allowance time calculation unit in the claims. Hereinafter, the virtual departure grace time t _{0 —} v at the time when automatic steering control is stopped is referred to as the initial virtual departure grace time t _{0 —} v.

In step S652, the change rate calculation unit 145 determines that the automatic steering control is stopped according to the following equation 7 from the initial virtual departure grace time t ₀ _v calculated in S651 and the initial steering angle Θ ₀ acquired in S41. The virtual request cut angle change rate ΔΘ ₀ _v is calculated. This S652 corresponds to a change rate calculation unit in the claims. The required turning angle change rate ΔΘ ₀ _v is the amount of change in steering angle per hour necessary for returning the steering of the vehicle to the neutral position before the vehicle deviates from the virtual front road boundary located in front of the vehicle. It is. Hereinafter, the virtual required turning angle change rate ΔΘ ₀ _v at the time when automatic steering control is stopped is referred to as an initial virtual required turning angle change rate ΔΘ ₀ _v.

Returning to FIG. 21, in step S66 following S65, the turning angle changing unit 146 transmits the amount of change in the steering angle per time to the EPS_ECU 5 according to the initial virtual required turning angle change rate ΔΘ ₀ _v calculated in S65. Thus, the operation of returning the steering of the own vehicle to the neutral position is started. This S66 corresponds to the cut angle changing portion in the claims. The process of S66 is performed in the same manner as S45 of the first embodiment.

In step S67, the evaluation index calculation unit 147 uses the initial own vehicle speed Vo ₀ acquired in S62 and the initial virtual forward road boundary distance Dr ₀ _v calculated in S64, according to the following equation 29, at the time when automatic steering control is stopped. A virtual value KdB ₀ _v of the approaching / separating state evaluation index is calculated. Hereinafter, the virtual value KdB ₀ _v of the approaching / separating state evaluation index when automatic steering control is stopped is referred to as a virtual initial value KdB ₀ _v.

  In the stop related processing, deceleration control is performed using the approach / separation state evaluation index KdB so that the vehicle does not deviate from the boundary of the virtual road and the vehicle driver decelerates without feeling uncomfortable.

  In step S68, virtual target deceleration calculation related processing is performed. Here, an outline of the virtual target deceleration calculation related processing will be described using the flowchart of FIG. In the virtual target deceleration calculation related processing, the target deceleration is calculated so that the driver does not deviate from the virtual road boundary and the driver of the vehicle does not feel uncomfortable.

In step S681, the target value setting unit 148 uses the initial virtual forward road boundary distance Dr ₀ _v calculated in S64, the virtual initial value KdB ₀ _v of the approaching / separating state evaluation index calculated in S67, and the current virtual forward road boundary distance Dr. _From N_v, a virtual target value (hereinafter referred to as virtual target value) KdB_t_v of the approaching / separating state evaluation index determined according to the following Expression 30 is set. The current forward road boundary distance Dr _{N —} v may be configured to be calculated by the virtual road boundary distance calculation unit 154. Further, when the flowchart of FIG. 21 is looped and the process is repeated, a configuration using the latest virtual forward road boundary distance Dr _{N —} v calculated in step S74 described later may be used.

In step S682, the target relative speed calculation unit 149 calculates a virtual target relative speed Vr_t_v corresponding to the virtual target value KdB_t_v of the approaching / separating state evaluation index set in S681 according to the following Expression 31. The virtual target relative speed Vr_t_v is a relative speed targeted by the host vehicle with respect to the virtual front road boundary located in front of the host vehicle. The virtual target relative speed Vr_t_v is substantially the target vehicle speed.

In step S683, the target deceleration calculation unit 150 uses the virtual target relative speed Vr_t_v calculated in S682 and the current relative speed Vr_p of the host vehicle with respect to the virtual front road boundary located in front of the host vehicle according to the following equation 32. Then, the virtual target deceleration Gd_v is calculated. S683 corresponds to a target deceleration calculation unit in the claims. As the current relative speed Vr_p, the current host vehicle speed Vo _N acquired from the VSC_ECU 1 by the vehicle speed specifying unit 142 is used. Ta in Expression 32 is a predetermined time set in advance.

  Returning to FIG. 21, in step S69 following S68, the braking control instruction unit 151 generates a braking force such that the actual deceleration detected by the G sensor 3 becomes the target deceleration Gd_v calculated in step S683. In the same manner as in S48 of the first embodiment, the VSC_ECU 1 is instructed. This S69 corresponds to a braking control instruction section in the claims.

The processing from step S70 to step S71 is the same as the processing from S49 to S50 in the first embodiment. Note that the processing from S65 to S66 and the processing from S67 to S69 may be performed in parallel, or the order may be switched. At step S72, the steering angle acquisition unit 141 acquires the current steering angle theta _N from the steering angle sensor 2.

In step S73, the vehicle speed identification unit 142 acquires the current vehicle speed Vo _N from VSC_ECU1. In step S74, the virtual road boundary distance calculation unit 154 calculates the current virtual forward road boundary distance Dr _{N —} v. The processing of S72 to S74 may be performed in parallel, or the processing order may be changed.

In step S75, a virtual request turning angle change rate calculation related process is performed. Here, an outline of the virtual request turning angle change rate calculation related process will be described using the flowchart of FIG. In the virtual request turning angle change rate calculation related processing, the virtual required turning angle change rate ΔΘ _{N —} v after the automatic steering control stop time is calculated.

In step S751, the deviation margin time calculation unit 144 uses the own vehicle speed Vo _N acquired in S73 and the virtual forward road boundary distance Dr _N _v calculated in S74, according to the following formula 6, to the current virtual departure grace time t _N. _v is calculated. This S751 also corresponds to the departure grace time calculation unit in the claims.

In step S752, the change rate calculation unit 145 changes the current virtual requested cut angle change according to the following equation 8 from the virtual departure delay time t _{N —} v calculated in S751 and the current steering angle Θ _N acquired in S72. The rate ΔΘ _{N —} v is calculated. S752 also corresponds to a change rate calculation unit in the claims.

Returning to FIG. 21, in step S76 subsequent to S75, the turning angle changing unit 146 transmits the amount of change in the steering angle per time to the EPS_ECU 5 according to the virtual required turning angle change rate ΔΘ _{N —} v calculated in S76. The operation of returning the steering of the own vehicle to the neutral position is continued. This S76 also corresponds to the cutting angle changing portion in the claims.

  In the stop related process, the value of the virtual front road boundary distance Dr_v is appropriately offset (for example, by subtracting 1 m, etc.), so that when the stop related process is completed and the vehicle stops, It is preferable not only to prevent the axle center from deviating from the virtual road boundary, but also to prevent the entire vehicle body from protruding from the virtual road boundary.

<Summary of Embodiment 2>
In the second embodiment, instead of the road outline that cannot be determined by the road outline determination unit 113 due to the failure of the detection by the distance measuring sensor 6, a virtual that follows the road outline that has been determined by the road outline determination unit 113 until then. Since it is the same as that of the first embodiment except that the road outline is estimated and used for calculating the virtual front road boundary distance, as in the first embodiment, when the automatic steering control is switched to the driver steering, It is possible to prevent the vehicle from deviating from the road boundary and to make it easier for the driver to determine the next steering operation.

  More specifically, according to the configuration of the second embodiment, even when detection by the distance measuring sensor 6 fails and automatic steering control is to be stopped, the vehicle deviates from the virtual front road boundary located in front of the host vehicle. As shown in FIG. 25, according to the virtual required turning angle change rate ΔΘ_v, which is the amount of change per hour in the steering angle Θ (that is, the steering turning angle Θ) required to return the steering of the host vehicle to the neutral position by The steering angle Θ of the own vehicle is sequentially changed.

FIG. 25 is a diagram showing changes in the virtual departure allowance time t_v, the steering angle Θ, and the host vehicle speed Vo from when the automatic steering control is stopped until the stop related processing is completed and the host vehicle stops. In FIG. 25, when the automatic steering control is stopped, that is, when the virtual front road boundary distance Dr_v is the initial virtual front road boundary distance Dr ₀ _v, the virtual front road boundary distance Dr_v is Dr ₁ _v, Dr ₂ _v. , Dr _N _v. The outline of the virtual road is indicated by a two-dot chain line. Also, O ₀ ~ O _E in FIG. 25, the vehicle to cancel at relevant process is completed after discontinue the automatic steering control shows each virtual road ahead boundary until it stops.

  According to the configuration of the second embodiment, as shown in FIG. 25, the steering of the host vehicle can be returned to the neutral position before deviating from the virtual front road boundary. Therefore, avoiding the situation where the vehicle deviates from the road boundary when the detection by the distance measuring sensor 6 of the own vehicle fails while traveling on a curved road and the automatic steering control is to be stopped. Is possible. Further, by bringing the steering of the host vehicle closer to the neutral position, it becomes easier for the driver to determine the next steering operation than when the steering is not brought closer to the neutral position.

  Furthermore, according to the configuration of the second embodiment, when the detection by the distance measuring sensor 6 fails and the automatic steering control is to be stopped, as shown in FIG. Using the value KdB_t_v, the braking force of the own vehicle is set so that the deceleration of the own vehicle becomes the virtual target deceleration Gd_v of the own vehicle so as not to deviate from the virtual front road boundary located in front of the own vehicle. Sequential control will be performed.

FIG. 26 shows changes in the virtual current value KdB _{N —} v and the vehicle speed Vo of the approaching / separating state evaluation index from when the automatic steering control is stopped until the stop related processing is completed and the vehicle stops. It is the figure which showed the approach / separation state evaluation parameter | index KdB.

In FIG. 26, when the automatic steering control is stopped, that is, when the virtual forward road boundary distance Dr_v is at the initial virtual forward road boundary distance Dr ₀ _v, the virtual forward road boundary distance Dr_v is Dr ₁ _v, Dr ₂ _v. , Dr _N _v. The outline of the virtual road is indicated by a two-dot chain line. O ₀ ~ O _E in FIG. 15, the vehicle to cancel at relevant process is completed after discontinue the automatic steering control shows each virtual road ahead boundary until it stops. In addition, in FIG. 26, as an example, the virtual target value KdB_t_v of the approaching / separating state evaluation index when automatic steering control is stopped is shown.

  According to the configuration of the second embodiment, it is possible to prevent the own vehicle from deviating from the virtual road boundary, and the deceleration control is performed using the approach / separation state evaluation index KdB. It is possible to perform deceleration without any problems.

  From the above, according to the configuration of the second embodiment, as shown in FIG. 27, it is possible to prevent the vehicle from deviating from the road boundary while returning the steering of the vehicle to the neutral position. .

  FIG. 27A shows that the vehicle is steered until the tire turning angle that maintains the above-mentioned road width direction distance L is reached. FIG. 27B shows a state in which the vehicle is steered until the tire turning angle that maintains the road width direction distance L is reached. 27C show a state in which the steering is returned to the neutral position. E of FIG. 27 has shown the state which returned the steering to the neutral position. The outline of the virtual road is indicated by a two-dot chain line.

  In the process of sequentially returning the steering angle Θ to the neutral position according to the virtual required turning angle change rate ΔΘ_v (see B to D in FIG. 27), the position of the virtual forward road boundary also changes, so the virtual forward road boundary distance Dr_v Will also change. On the other hand, according to the second embodiment, the virtual target deceleration Gd_v is sequentially calculated from the virtual forward road boundary distance Dr_v and the host vehicle speed Vo that are sequentially changed, and the braking control is performed. As the position of the virtual front road boundary for the vehicle changes, the braking control is performed so as not to deviate from the virtual front road boundary. As a result, it is possible to prevent the vehicle from deviating from the road boundary while returning the steering of the vehicle to the neutral position.

<Modification 1>
In the above-described embodiment, when the manual steering start determination unit 105 determines that the steering operation of the host vehicle has been started by the user, the instruction from the braking control instruction unit 151 to the VSC_ECU 1 is terminated, and automatic braking control is performed. Although the configuration for termination is shown, it is not necessarily limited to this. For example, instead of ending the automatic braking control, the braking force may be set to be smaller than the braking force in the case where the deceleration of the host vehicle is set to the target deceleration. In other words, the deceleration by the automatic braking control may be reduced as an absolute value.

  According to this, the deceleration by automatic braking control different from the driver's intention is reduced as an absolute value, and it is possible to smoothly shift to acceleration / deceleration and steering operation by the driver's brake operation.

<Modification 2>
In the above-described embodiment, the case where the deceleration control is performed using the approach / separation state evaluation index so as not to deviate from the road boundary has been described as an example, but the present invention is not necessarily limited thereto. For example, the speed reduction control may be performed so as not to deviate from the road boundary by the speed reduction control without using the approach / separation state evaluation index.

<Modification 3>
In the above-described embodiment, the configuration using the steering angle detected by the steering angle sensor 2 in the automatic steering control is shown, but the configuration is not necessarily limited thereto. For example, automatic steering control may be performed using a yaw rate detected by a yaw rate sensor.

  When the third modification is adopted in the first embodiment, the first failure determination unit 102 determines whether or not the detection by the yaw rate sensor has failed, and the first failure determination that the detection by the yaw rate sensor has failed. What is necessary is just to set it as the structure which the automatic steering control cancellation part 103 stops automatic steering control, when it determines in the part 102. FIG.

<Modification 4>
In Embodiment 1, although the structure which determines a road external shape from the detection result of autonomous sensors, such as a radar and a camera, was shown, it does not necessarily restrict to this. For example, it is good also as a structure which determines a road external shape based on the information obtained from other vehicles, such as a preceding vehicle, by inter-vehicle communication.

  In the fourth modification, the vehicle control ECU 10 determines the travel locus of the preceding vehicle based on the vehicle information such as the vehicle speed Vp and the steering angle Θ of the preceding vehicle acquired by inter-vehicle communication. As an example, the vehicle position at a certain point in time is set as a starting point on the two-dimensional coordinates, and is ahead of the starting point by a length corresponding to the distance between the own vehicle detected based on the signal from the distance measuring sensor 6 and the preceding vehicle. The separated position is set as the initial position of the traveling vehicle. Then, based on the vehicle speed Vp and the steering angle Θ of the preceding vehicle that are sequentially acquired, the traveling locus of the preceding vehicle is determined by sequentially calculating the traveling locus points following the initial position.

  Subsequently, a configuration may be adopted in which a virtual road outline ahead is determined from the determined travel locus of the preceding vehicle as a starting point. For example, a road outline having a boundary line with a width corresponding to a distance corresponding to a distance of 1.75 m on the left and right with the travel locus of the preceding vehicle as a center line may be determined. Then, after determining the virtual road outline, the same processing as described in the first and second embodiments is performed.

  In addition, as a configuration for performing the determination of the traveling locus of the preceding vehicle and the determination of the road outer shape with the device mounted on the preceding vehicle, and acquiring the traveling locus and the information of the road outer shape transmitted from the preceding vehicle by inter-vehicle communication. Also good.

  Moreover, it is good also as a structure which determines the driving | running | working locus | trajectory and road outline of a preceding vehicle based on the inner / outer wheel speed ratio of a preceding vehicle. Specifically, based on the fact that the angular velocity of the inner and outer wheels is the same, the radius of curvature of the curved road is calculated from the inner and outer wheel speed ratio by a known method, and the travel locus and road outline are determined. Good.

  In addition, the configuration may be such that the travel locus of the preceding vehicle and the road profile are determined based on the yaw rate of the preceding vehicle. Moreover, it is good also as a structure which determines a driving | running | working locus | trajectory or a road external shape using together the speed of a preceding vehicle, a steering angle, inner / outer wheel speed ratio, and a yaw rate. In this case, the values calculated by different methods may be averaged.

  In the case where the fourth modification is adopted in the second embodiment, the second failure determination unit 106 receives information from other vehicles when the information from other vehicles such as the preceding vehicle cannot be received for a predetermined time or more by inter-vehicle communication. What is necessary is just to set it as the structure determined with the acquisition of the information for road outline determination failing. Then, when the second failure determination unit 106 determines that the failure has occurred, the automatic steering control stop unit 103a may be configured to stop the automatic steering control.

<Modification 5>
Moreover, it is good also as a structure which determines a road external shape based on the information obtained from the roadside machine etc. by road-to-vehicle communication. In the case of the fifth modification, the vehicle outer shape may be determined by the vehicle control ECU 10 based on information acquired from a roadside machine or the like by road-to-vehicle communication.

  The information acquired from the roadside machine or the like may be any information as long as the vehicle control ECU 10 can determine the road profile of the road area where the host vehicle should travel. For example, it may be information indicating the linear structure of the road around the target intersection position, and may be road linear information including information on the position of the target intersection. The road alignment information is information such as the position of the target intersection (latitude and longitude) as the positioning result of the satellite positioning system, the distance to the predetermined structural change point based on the position of the target intersection, the dimension of the road alignment, etc. To do.

  In addition, it may be travel history information obtained by collecting past travel histories of a plurality of vehicles. The travel history information is information on vehicle speed and steering angle, for example.

  The vehicle control ECU 10 determines the road outer shape of the road area where the host vehicle should travel based on the information acquired from the roadside machine etc., and after determining the road outer shape, the vehicle control ECU 10 is the same as described in the first embodiment. Processing shall be performed.

  In the case where the fifth modification is adopted in the second embodiment, the second failure determination unit 106 determines the road contour from the roadside machine when information from the roadside machine or the like cannot be received for a predetermined time or more by road-to-vehicle communication. It may be configured to determine that acquisition of information for use has failed. Then, when the second failure determination unit 106 determines that the failure has occurred, the automatic steering control stop unit 103a may be configured to stop the automatic steering control.

<Modification 6>
In the above-described embodiment, the automatic steering control is performed to travel using the distance to the road boundary as the optimum distance, and thus the configuration of determining the outer shape of the road region where the host vehicle is to travel is shown, but the present invention is not necessarily limited thereto. For example, when performing automatic steering control that travels along the center line of the road width and travels using the distance to the road boundary as the optimum distance, the shape of the center line is not determined as the road shape. It is good also as a structure which only determines.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the technical means disclosed in different embodiments can be appropriately combined. Such embodiments are also included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Vehicle control ECU (behavior control apparatus for vehicles), 102 1st failure determination part, 103, 103a Automatic steering control stop part, 106 2nd failure determination part, 111 Current position specific | specification part, 113 Road external shape determination part (Road shape determination) Part), 114 road boundary distance calculation part (boundary distance calculation part), 127 steering instruction part (automatic steering control instruction part), 142 vehicle speed specifying part, S45, S55, S66, S76 turning angle changing part, S48, S69 Braking control Instruction unit, S442, S542, S652, S752 Change rate calculation unit

Claims (8)

Mounted on the vehicle,
A current position specifying unit (111) for sequentially specifying the current position of the vehicle;
A road shape determination unit (113) for sequentially determining the road shape of the road area in which the vehicle is to travel;
Vehicle behavior control including an automatic steering control instructing unit (127) for performing automatic steering control for sequentially controlling a steering angle so that the vehicle travels along the road shape sequentially determined by the road shape determining unit. A device (10) comprising:
A vehicle speed specifying unit (142) for sequentially specifying the host vehicle speed, which is the speed of the host vehicle,
Based on the current position of the own vehicle sequentially specified by the current position specifying unit and the road shape sequentially determined by the road shape determining unit, a forward road from the own vehicle to a front road boundary located in front of the own vehicle A boundary distance calculation unit (114) for sequentially calculating the boundary distance;
A first failure determination unit (102) for determining whether or not detection by a turn-related sensor for detecting the degree of turning of the vehicle used for the automatic steering control has failed;
An automatic steering control stopping unit (103) for stopping the automatic steering control when the first failure determining unit determines that the detection by the turning-related sensor has failed;
When the automatic steering control is stopped, based on the front road boundary distance sequentially calculated by the boundary distance calculating unit and the own vehicle speed sequentially specified by the vehicle speed specifying unit, the vehicle located in front of the own vehicle Change rate calculation units (S442, S542) that sequentially calculate the required turning angle change rate, which is the amount of change in the steering turning angle per time, required to return the steering of the host vehicle to the neutral position before deviating from the front road boundary. )When,
A turning angle changing unit (S45, S55) for sequentially changing the steering turning angle of the host vehicle according to the required turning angle change rate sequentially calculated by the change rate calculating unit;
When the automatic steering control is stopped, based on the front road boundary distance sequentially calculated by the boundary distance calculating unit and the own vehicle speed sequentially specified by the vehicle speed specifying unit, the vehicle located in front of the own vehicle A target deceleration calculation unit (S473) that sequentially calculates a target deceleration of the host vehicle so as not to deviate from the road boundary ahead;
A vehicle behavior control device comprising: a braking control instructing unit (S48) that performs braking control for sequentially controlling the braking force of the host vehicle so that the deceleration of the host vehicle becomes the target deceleration. In claim 1,
When the automatic steering control is stopped, the front road boundary distance (Dr ₀ ) at the stop time calculated by the boundary distance calculation unit and the own vehicle speed (Vo ₀ ) at the stop time specified by the vehicle speed specifying unit. From the above, in accordance with the equation (1), the deviation postponement time (t ₀ ) until the vehicle departs from the front road boundary located in front of the host vehicle at the time of cancellation is calculated. From the forward road boundary distance (Dr _N ) sequentially calculated by the calculation unit and the own vehicle speed (Vo _N ) sequentially specified by the vehicle speed specifying unit, the departure grace time (t _N ) is sequentially calculated according to the equation (2). A departure grace time calculating unit (S441, S541),
When the automatic steering control is stopped, from the steering angle (Θ ₀ ) of the own vehicle at the time of cancellation and the integrated change amount of the steering angle changed by the angle change unit from the time of cancellation to the present A turning angle estimation unit (S51) for sequentially estimating the current steering turning angle (Θ _N ),
The rate of change calculation unit
At the time of stopping the automatic steering control, the departure grace time calculating unit calculates the departure grace time (t ₀ ) until the vehicle departs from the front road boundary located in front of the host vehicle at the time of suspension, and the The required turning angle change rate (ΔΘ ₀ ) at the stop point is calculated from the steering angle (Θ ₀ ) of the vehicle according to the equation (3). From the deviation postponement time (t _N ) sequentially calculated in step (1) and the current steering angle (Θ _N ) sequentially estimated by the turning angle estimator, the current required turning angle change rate ( (ΔΘ _N ) is sequentially calculated.

t ₀ : Deviation grace time [sec] when automatic steering control is stopped
Dr ₀ : road boundary distance ahead [m] when automatic steering control is stopped
Vo ₀ : The vehicle speed [m / sec] at the time when automatic steering control is stopped

t _N : Deviation grace time [sec] after the time point when automatic steering control is stopped
Dr _N : the road boundary distance ahead [m] after the automatic steering control stop point has passed
Vo _N : Vehicle speed [m / sec] after own steering control has been stopped

ΔΘ ₀ : Requested turning angle change rate [deg / sec] when automatic steering control is stopped
Θ ₀ : Steering angle [deg] when automatic steering control is stopped

ΔΘ _N : Current required cutting angle change rate [deg / sec]
Θ _N : Current steering angle [deg] estimated by the angle estimator In claim 1 or 2,
An index representing the approaching / separating state with respect to the front road boundary in consideration of the speed at which the vehicle approaches the front road boundary, and increases as the speed at which the vehicle approaches the front road boundary increases, An evaluation index calculation unit (147) for calculating an approach / separation state evaluation index, which is an index in which an increase gradient with respect to a change in which the road boundary distance becomes shorter becomes steeper as the forward road boundary distance becomes shorter;
The target deceleration calculation unit is determined from the approach / separation state evaluation index calculated by the evaluation index calculation unit and the front road boundary distance sequentially calculated by the boundary distance calculation unit, and is located in front of the host vehicle. A vehicle behavior control device characterized by sequentially calculating a deceleration for adjusting an actual vehicle speed to a target speed value of the vehicle with respect to a road boundary as the target deceleration. Mounted on the vehicle,
A current position specifying unit (111) for sequentially specifying the current position of the vehicle;
A road shape determination unit (113) for sequentially determining the road shape of the road area in which the vehicle is to travel;
Vehicle behavior control including an automatic steering control instructing unit (127) for performing automatic steering control for sequentially controlling a steering angle so that the vehicle travels along the road shape sequentially determined by the road shape determining unit. A device (10) comprising:
The road shape determining unit is for determining the road shape of the road region where the vehicle should travel, using road shape determination information that can determine the road shape of the road region existing in front of the vehicle.
A vehicle speed specifying unit (142) for sequentially specifying the host vehicle speed, which is the speed of the host vehicle,
A second failure determination unit (106) for determining whether or not the acquisition of the road shape determination information has failed;
An automatic steering control stopping unit (103a) for stopping the automatic steering control when the second failure determining unit determines that acquisition of the road shape determination information has failed;
A virtual road shape estimation unit (153) for estimating a virtual road shape following the road shape based on the road shape determined so far by the road shape determination unit when the automatic steering control is stopped When,
When the automatic steering control is stopped, the vehicle from the own vehicle based on the current position of the own vehicle sequentially specified by the current position specifying unit and the virtual road shape estimated by the virtual road shape estimating unit. A virtual boundary distance calculation unit (154) that calculates a virtual front road boundary distance to a virtual front road boundary that is a virtual front road boundary located in front of the vehicle;
When the automatic steering control is stopped, the vehicle is positioned in front of the vehicle based on the virtual forward road boundary distance sequentially calculated by the virtual boundary distance calculation unit and the own vehicle speed sequentially specified by the vehicle speed specifying unit. A change rate calculation unit that sequentially calculates a required turning angle change rate that is a change amount per hour of the steering turning angle necessary to return the steering of the host vehicle to the neutral position before deviating from the virtual forward road boundary. S652, S752),
A turning angle changing unit (S66, S76) for sequentially changing the steering turning angle of the host vehicle according to the required turning angle change rate sequentially calculated by the change rate calculating unit;
When the automatic steering control is stopped, the vehicle is positioned in front of the vehicle based on the virtual forward road boundary distance sequentially calculated by the virtual boundary distance calculation unit and the own vehicle speed sequentially specified by the vehicle speed specifying unit. A target deceleration calculation unit (S683) for sequentially calculating a target deceleration of the host vehicle so as not to deviate from the virtual forward road boundary;
A vehicle behavior control apparatus comprising: a braking control instruction unit (S69) for performing braking control for sequentially controlling the braking force of the host vehicle so that the deceleration of the host vehicle becomes the target deceleration. In claim 4,
When the automatic steering control is stopped, the virtual front road boundary distance (Dr ₀ _v) at the stop time calculated by the virtual boundary distance calculation unit and the own vehicle speed at the stop time specified by the vehicle speed specifying unit ( From Vo ₀ ), the virtual departure grace time (t ₀ _v) until the departure from the virtual front road boundary located in front of the vehicle at the time of cancellation is calculated according to the equation (5), while the time of cancellation has passed. Thereafter, the virtual forward road boundary distance (Dr _{N —} v) sequentially calculated by the virtual boundary distance calculating unit and the own vehicle speed (Vo _N ) sequentially specified by the vehicle speed specifying unit are used to calculate the virtual according to the equation (6). A virtual departure grace time calculation unit (S651, S751) that sequentially calculates the departure grace time (t _N _v);
The rate of change calculation unit
At the time of stopping the automatic steering control, a virtual departure time (t ₀ _v) until the departure from the virtual front road boundary located in front of the host vehicle at the time of stop calculated by the virtual departure time calculation unit, The required turning angle change rate (ΔΘ ₀ _v) at the stop point is calculated from the steering angle (Θ ₀ ) of the vehicle at the stop point according to the equation (7). From the virtual departure grace time (t _{N —} v) sequentially calculated by the virtual departure grace time calculation unit and the current steering turning angle (Θ _N ), the current requested turning angle change rate (ΔΘ) according to the equation (8). the vehicle behavior control apparatus characterized by sequentially calculating the _N _v).

t ₀ _v: Virtual departure grace time [sec] when automatic steering control is stopped
Dr ₀ _v: Virtual forward road boundary distance [m] at the time when automatic steering control is stopped
Vo ₀ : The vehicle speed [m / sec] at the time when automatic steering control is stopped

t _{N —} v: Virtual departure grace time [sec] after the time point when automatic steering control is stopped
Dr _{N —} v: Virtual forward road boundary distance [m] after the point of time when automatic steering control is stopped
Vo _N : Vehicle speed [m / sec] after own steering control has been stopped

ΔΘ ₀ _v: Requested turning angle change rate [deg / sec] when automatic steering control is stopped
Θ ₀ : Steering angle [deg] when automatic steering control is stopped

ΔΘ _{N —} v: Current required cut angle change rate [deg / sec]
Θ _N : Current steering angle [deg] estimated by the angle estimator In claim 4 or 5,
An index that represents the approaching / separating state with respect to the virtual front road boundary in consideration of the speed at which the vehicle approaches the virtual front road boundary, and increases as the speed at which the vehicle approaches the virtual front road boundary increases. An evaluation index calculation unit (147) for calculating an approach / separation state evaluation index, which is an index in which an increase gradient with respect to a change in which the virtual front road boundary distance becomes shorter becomes steeper as the virtual front road boundary distance becomes shorter,
The target deceleration calculation unit is located in front of the host vehicle determined from the approach / separation state evaluation index calculated by the evaluation index calculation unit and the virtual forward road boundary distance sequentially calculated by the virtual boundary distance calculation unit. A vehicle behavior control apparatus, wherein a deceleration for adjusting an actual vehicle speed to a target speed value of the vehicle with respect to the virtual front road boundary is sequentially calculated as the target deceleration. In any one of Claims 1-6,
A manual steering start determining unit (105) for determining whether or not the steering operation of the host vehicle has been started by the user after the automatic steering control is stopped;
The vehicle behavior control device according to claim 1, wherein the braking control instruction unit stops the braking control when the manual steering start determination unit determines that a steering operation of the host vehicle is started by a user. In any one of Claims 1-6,
A manual steering start determining unit (105) for determining whether or not the steering operation of the host vehicle has been started by the user after the automatic steering control is stopped;
When the manual steering start determination unit determines that the steering operation of the host vehicle has been started by the user, the braking control instruction unit is configured so that the deceleration of the host vehicle becomes the target deceleration. A vehicle behavior control apparatus characterized in that a braking force is made smaller than a braking force.

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