Driving control method and driving control device

Abstract

The driving control device (100) of the present invention uses a processor (10) having a first control unit (11) that executes lane keeping control and a second control unit (12) that executes deviation prevention control, and executes driving assistance control for the own vehicle (1). The processor (10) determines whether the second control unit (12) starts deviation prevention control during the execution of the lane keeping control by the first control unit (11). When it is determined that the second control unit (12) starts deviation prevention control during the execution of the lane keeping control, the processor (10) ends the currently executed lane keeping control, starts deceleration control for the own vehicle (1), and continues deviation prevention control until the own vehicle (1) stops. When the own vehicle (1) stops by the deceleration control, the currently executed deviation prevention control is ended.

Description

Technical Field

[0001] The present invention relates to a driving control method and a driving control device. Background Art

[0002] The driving control device described in Patent Document 1 performs lane keeping control and deviation prevention control based on the lane width of the driving lane in which the own vehicle is traveling and the vehicle speed of the own vehicle.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2015-069341

[0006] Problems to be Solved by the Invention

[0007] However, the driving control device described in Patent Document 1 is not a device that determines whether an abnormality has occurred in the function of executing lane keeping control and performs control based on the determination result. Summary of the Invention

[0008] The problem to be solved by the present invention is to provide a driving control method and a driving control device that can determine a situation in which an abnormality may have occurred in the execution function of lane keeping control and control the driving of the own vehicle based on the determination result when controlling the own vehicle by lane keeping control and deviation prevention control.

[0009] The present invention solves the above problems by the following processing: determining whether the second control unit starts deviation prevention control during the execution of lane keeping control by the first control unit, and when it is determined that the second control unit starts the deviation prevention control during the execution of lane keeping control, ending the currently executed lane keeping control, starting deceleration control of the own vehicle, and continuously performing deviation prevention control until the own vehicle stops by the deceleration control, and ending the currently executed deviation prevention control when the own vehicle stops by the deceleration control.

[0010] Advantages of the Invention

[0011] According to the present invention, the following effects are obtained: The driving control device determines whether the second control unit starts deviation prevention control during the execution of lane keeping control by the first control unit. Therefore, when controlling the own vehicle by lane keeping control and deviation prevention control, it is possible to determine a situation in which an abnormality may have occurred in the execution function of lane keeping control and control the driving of the own vehicle based on the determination result. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a block diagram showing the configuration of the driving control device of the present embodiment.

[0013] Figure 2 This is a diagram showing an example of the positional relationship between the host vehicle and the lane boundary line when it is determined that the host vehicle has deviated from the lane.

[0014] Figure 3 It represents Figure 1 A flowchart showing the sequence of the driving control method executed by the driving control device shown. Detailed implementation

[0015] Hereinafter, embodiments of the present invention will be described based on the accompanying drawings.

[0016] Figure 1 This is a block diagram showing the structure of the host vehicle 1 and the driving control device 100 that controls the autonomous driving of the host vehicle 1. The host vehicle 1 includes: a driving control device 100, a detection device 101, a host vehicle position acquisition unit 102, a map database 103, in-vehicle equipment 104, an output device 105, a steering device 106a, a braking device 106b, and a driving device 106c. The driving control device 100 controls the steering device 106a, the braking device 106b, and the driving device 106c of the host vehicle 1 by executing a program stored in the ROM by the CPU, thereby performing driving assistance control.

[0017] The detection device 101 is, for example, an in-vehicle camera that captures the surroundings of the host vehicle 1. The detection device 101 detects the lane boundary lines B1, B2 of the driving lane L on which the host vehicle 1 is traveling (refer to Figure 2 ). The detection result of the detection device 101 is output to the driving control device 100 at a predetermined time interval.

[0018] The host vehicle position acquisition unit 102 is composed of a GPS unit, a gyro sensor, a vehicle speed sensor, etc. The host vehicle position acquisition unit 102 detects radio waves transmitted from multiple communication satellites through the GPS unit, periodically acquires the position information of the host vehicle 1, and based on the acquired position information of the host vehicle 1, the angular change information acquired from the gyro sensor, and the vehicle speed acquired from the vehicle speed sensor, detects the current position of the host vehicle 1. The position information of the host vehicle 1 detected by the host vehicle position acquisition unit 102 is output to the driving control device 100 at a predetermined time interval.

[0019] The map database 103 is a memory configured to store high-precision digital map information (high-precision map, dynamic map) including identification information of multiple lanes possessed by a road and be accessible from the driving control device 100. The map information of the map database 103 also includes information about the road and / or the size of the curved road of the lane and its curve (such as curvature or radius of curvature).

[0020] The in-vehicle device 104 is various devices mounted on a vehicle and operates by being operated by a driver. The in-vehicle device 104 includes a steering wheel 104a. In addition, as other in-vehicle devices 104, there are listed: an accelerator pedal, a brake pedal, a navigation device, a direction indicator, a wiper, a lamp, a horn, and other specific switches, etc. When the in-vehicle device 104 is operated by the driver, its information is output to the driving control device 100.

[0021] The output device 105 is, for example, a display that outputs text information and / or image information or a speaker that outputs sound information.

[0022] The steering device 106a has a steering actuator. In addition, the steering actuator includes an electric motor etc. mounted on the column shaft of the steering gear. The steering device 106a performs the steering control of the vehicle 1 based on the steering angle of the steering wheel 104a and the control signal input from the driving control device 100. The braking device 106b includes a brake actuator. The braking device 106b controls the braking action of the vehicle 1 based on the stroke amount of the brake pedal (not shown), etc., or the control signal input from the driving control device 100. In addition, the driving device 106c controls the action of the drive mechanism (including the action of the internal combustion engine in an engine vehicle, the action of the driving electric motor in an electric vehicle system, and also the torque distribution between the internal combustion engine and the driving electric motor in a hybrid vehicle) based on the stroke amount of the accelerator pedal (not shown), etc., or the control signal input from the driving control device 100.

[0023] Next, use Figure 1 and Figure 2 to explain the structure of the driving control device 100 in detail.

[0024] In addition, in the following description, it is assumed that the driving control device 100 controls the driving of the vehicle 1 in the hands-off mode. The hands-off mode is a mode in which the driving control device 100 allows the vehicle 1 to travel in a state where the driver has released their hands from the steering gear of the vehicle 1.

[0025] As Figure 1As shown, the driving control device 100 includes a processor 10. The processor 10 is composed of a ROM (Read Only Memory) that stores a program for controlling the driving of the vehicle 1, a CPU (Central Processing Unit) that executes the program stored in the ROM, and a RAM (Random Access Memory) that functions as an accessible storage device. Additionally, as an operation circuit, instead of or together with the CPU (Central Processing Unit), an MPU (Micro Processing Unit), a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), etc. can be used. The processor 10 includes an abnormality determination unit 14 and a vehicle control unit 15. The abnormality determination unit 14 has a first abnormality determination unit 14a and a second abnormality determination unit 14b. The vehicle control unit 15 has a first control unit 11, a second control unit 12, and a vehicle speed control unit 13. The first control unit 11, the second control unit 12, the vehicle speed control unit 13, the first abnormality determination unit 14a, and the second abnormality determination unit 14b execute programs for realizing the respective functions of the processor 10.

[0026] In addition, Figure 1 in, the driving control device 100 is mounted on the vehicle 1, but is not limited thereto, and the driving control device 100 can also be a device for remotely operating the vehicle 1.

[0027] The first control unit 11 executes lane keeping control for maintaining (holding) the lateral position P of the vehicle 1 at a specified position within the driving lane L (refer to Figure 2)。In addition, the lateral position P of the host vehicle 1 when the first control unit 11 executes lane keeping control is maintained near the center of the driving lane L. That is, the first control unit 11 maintains the lateral position P of the host vehicle 1 at a position near the center of the driving lane L, which is a specified position, based on the lane boundary lines B1 and B2 detected by the detection device 101 and the driving lane information in the map database 103. More specifically, the first control unit 11 controls the steering device 106a in such a way that the lateral position P of the host vehicle 1 is maintained at the specified position (the position near the center of the driving lane L) without causing discomfort to the driver, according to the influence when switching the information acquisition unit for the driving lane L between the detection device 101 and the map database 103, the influence of the road environment (inclination, change in the curvature of the driving lane L, change in the road width), and / or the influence of a crosswind. In addition, the first control unit 11 may also execute lane keeping control by controlling the braking device 106b to adjust the yaw angle of the host vehicle 1.

[0028] The second control unit 12 executes deviation prevention control to prevent the host vehicle 1 from deviating from the driving lane L based on the positions of the lane boundary lines B1 and B2 detected by the detection device 101. The second control unit 12 starts the deviation prevention control when at least a part of the body of the host vehicle 1 deviates from the lane boundary lines B1 and B2 of the driving lane L, and controls the steering device 106a to adjust the orientation of the host vehicle 1 so that the host vehicle 1 returns to the inside of the driving lane L. In addition, the second control unit 12 may execute deviation prevention control by controlling the braking device 106b to adjust the yaw angle of the vehicle 1.

[0029] In addition, during the period when the first control unit 11 functions normally, the deviation prevention control function of the second control unit 12 is also in the ON state. "The second control unit 12 starts the deviation prevention control" means that the second control unit 12 starts to output a control signal to the vehicle control unit 15 based on the deviation prevention control function. "The second control unit 12 continues the deviation prevention control" means that the second control unit 12 continuously outputs a control signal to the vehicle control unit 15 based on the deviation prevention control function.

[0030] In addition, the second control unit 12 may also control the steering device 106a to adjust the driving direction of the host vehicle 1 so that the host vehicle 1 remains inside the driving lane L when it is predicted that at least a part of the body of the host vehicle 1 will deviate from the lane boundary lines B1 and B2 of the driving lane L. Specifically, in Figure 2When the orientation of the vehicle 1 is not parallel to the extension direction of the driving lane L, the second control unit 12 calculates the shortest time T1 required until the orientation of the vehicle 1 becomes parallel to the extension direction of the driving lane L. Then, the second control unit 12 calculates the lateral movement amount X of the vehicle 1 assuming that the orientation of the vehicle 1 becomes parallel to the extension direction of the driving lane L after the shortest time T1. When the lateral movement amount X is greater than the distance D between the current lateral position P of the vehicle and the lane boundary line B1 (X > D), the second control unit 12 predicts that at least a part of the body of the vehicle 1 deviates from the lane boundary line B1 of the driving lane L and starts deviation prevention control. On the other hand, when the lateral movement amount X is less than or equal to the distance D between the current lateral position P of the vehicle and the lane boundary line B1 (X ≤ D), the second control unit 12 determines that the vehicle 1 does not deviate from the driving lane L and does not start deviation prevention control.

[0031] The calculation methods of the shortest time T1 and the lateral movement amount X are further specifically described.

[0032] First, the second control unit 12 obtains the steering speed limit value δ' of the vehicle 1.

[0033] Then, the second control unit 12 adds the steering angle change amount δ(t) obtained by integrating the steering speed limit value δ' with respect to time t to the current initial steering angle δ(0) to generate the following formula (1) representing the steering angle δ after time t.

[0034] δ = δ(0) + δ(t) (1)

[0035] Furthermore, the second control unit 12 transforms the above formula (1) into an arithmetic expression representing the body angle change rate θ' (yaw rate) according to the vehicle model of the vehicle 1. Then, the second control unit 12 integrates the body angle change rate θ' (yaw rate) with respect to time t to calculate the body angle change amount θ(t). Furthermore, the second control unit 12 adds the body angle change amount θ(t) to the current initial body angle θ(0) to generate the following arithmetic expression (2) representing the body angle θ after time t. In addition, in the generation of formula (2), since it is integrated twice with respect to time (t), formula (2) is a quadratic function formula of time t.

[0036] θ = θ(0) + θ(t) (2)

[0037] The second control unit 12 calculates the time t when θ = 0 based on the above formula (2). The time t when θ = 0 is "the shortest time T1 required until the orientation of the vehicle 1 becomes parallel to the extension direction of the driving lane L".

[0038] Furthermore, the second control unit 12 generates the following equation (3) representing the lateral movement speed Vy(t) of the host vehicle 1 based on the vehicle speed V of the host vehicle 1 and the vehicle body angle change amount θ(t).

[0039] Vy(t) = V × sinθ(t) (3)

[0040] Then, the second control unit 12 integrates Vy(t) represented by the above equation (3) in the shortest time T1 to calculate the lateral movement amount X. The second control unit 12 determines whether the host vehicle 1 has deviated from the driving lane L by comparing the lateral movement amount X with the distance D from the current lateral position P of the host vehicle 1 to the lane boundary line B1.

[0041] In addition, when the second control unit 12 starts the deviation prevention control when the driving control device 100 controls the driving of the host vehicle 1 in the hand - off mode, the output device 105 may also output a hand - holding request message for requesting the driver to hold the steering wheel 104a of the host vehicle 1. In addition, after the control right is restored to the driver, the driving control device 100 may also stop the driving assistance control including the lane keeping control and the deviation prevention control.

[0042] In addition, Figure 1 the illustrated vehicle speed control unit 13 controls the vehicle speed V and acceleration / deceleration of the host vehicle 1 by controlling the braking device 106b and the driving device 106c.

[0043] In addition, the first abnormality determination unit 14a determines whether an abnormality has occurred in the first control unit 11 (whether the first control unit 11 has failed). Specifically, the first abnormality determination unit 14a determines whether the second control unit 12 starts the deviation prevention control during the execution of the lane keeping control by the first control unit 11. When the second control unit 12 starts the deviation prevention control during the execution of the lane keeping control, since there is a high possibility that the lane keeping control does not function properly, the first abnormality determination unit 14a determines that an abnormality has occurred in the first control unit 11.

[0044] In addition, in the present embodiment, "occurring an abnormality" means that the execution of the control function fails.

[0045] When the first abnormality determination unit 14a determines that an abnormality has occurred in the first control unit 11 (the first control unit 11 has failed), that is, when the second control unit 12 starts the deviation prevention control during the execution of the lane keeping control, the first control unit 11 ends the lane keeping control. In addition, when the first abnormality determination unit 14a determines that an abnormality has occurred in the first control unit 11, the processor 10 outputs an alarm including the hand-held request information to the output device 105. Furthermore, the vehicle speed control unit 13 outputs control signals to the braking device 106b and the driving device 106c, and starts the deceleration control of the own vehicle 1. In addition, the second control unit 12 continuously performs the deviation prevention control until the own vehicle 1 that has decelerated by the deceleration control stops, and ends the deviation prevention control when the own vehicle 1 stops. In addition, when manual driving by the driver starts during the deceleration of the own vehicle 1, the vehicle speed control unit 13 ends the deceleration control before the own vehicle 1 stops.

[0046] On the other hand, the second abnormality determination unit 14b always determines whether an abnormality has occurred in the second control unit 12 (whether the second control unit has failed) even during the period when the deviation prevention control is not executed. That is, the second abnormality determination unit 14b determines whether an abnormality has occurred in the second control unit 12 before the second control unit 12 starts the deviation prevention control. In addition, when the second abnormality determination unit 14b determines that an abnormality has occurred in the second control unit 12, the processor 10 of the driving control device 100 ends the driving assistance control including the lane keeping control and the deviation prevention control. In addition, when a system error of the second control unit 12 is detected, the second abnormality determination unit 14b determines that an abnormality has occurred in the second control unit 12. In addition, the second abnormality determination unit 14b determines whether the internally calculated result calculated periodically deviates from the reference value by more than a specified value. This specified value is appropriately set based on experimental results and the like according to the system used. The second control unit 12 controls the own vehicle 1 so as not to deviate from the driving lane L. In contrast, the first control unit 11 calculates in such a way that the own vehicle 1 travels on the path in the center of the lane during the execution of the driving assistance control of the own vehicle 1. Therefore, the internal calculation of the first control unit 11 is more than that of the second control unit 12. Since the output value is output by synthesizing these calculation results, it is difficult for the first abnormality determination unit 14a to determine the deviation of the internal calculation result of the first control unit 11. In addition, even when the output value after synthesizing a plurality of calculation results is constant, the internal calculations may be different, and it is difficult for the first abnormality determination unit 14a to correctly determine the deviation of the internal calculation result of the first control unit 11.

[0047] In addition, when the driving control device 100 performs the driving assistance control of the vehicle 1 in the hand-held mode, if the abnormality determination unit 14 determines that an abnormality has occurred in the first control unit 11 or the second control unit 12, the driving control device 100 can also control the vehicle 1 in a manner that does not allow the driving assistance mode to be switched to the hands-off mode.

[0048] Next, refer to Figure 3 Describe the steps of the driving control method executed by the driving control device 100.

[0049] First, in step S1, the second abnormality determination unit 14b determines whether an abnormality has occurred in the second control unit 12. If an abnormality has occurred in the second control unit 12, in step S8, the driving control device 100 ends the driving assistance control.

[0050] Next, in step S2, the first abnormality determination unit 14a determines whether the second control unit 12 starts the deviation prevention control during the execution of the lane keeping control of the first control unit 11. If the second control unit 12 does not start the deviation prevention control during the execution of the lane keeping control of the first control unit 11, the process ends.

[0051] If, in step S2, the first abnormality determination unit 14a determines that the second control unit 12 starts the deviation prevention control during the execution of the lane keeping control of the first control unit 11, in step S3, the first abnormality determination unit 14a determines that an abnormality has occurred in the first control unit 11. In addition, in this determination, if it is determined from external information or the like that a strong crosswind above a specified level is blowing, or if it is determined from map information that the road surface has a large slope above a specified level, etc., and if the driving control device 100 has previously obtained information on a location where it is determined that it is difficult for the vehicle 1 to travel within the lane by lane keeping control, the determination of whether an abnormality has occurred in the first control unit 11 at this location can also be withheld (suspended).

[0052] Next, in step S4, the first control unit 11 ends the lane keeping control.

[0053] Furthermore, next, in step S5, the vehicle speed control unit 13 starts the deceleration control.

[0054] In addition, the process of step S4 and the process of step S5 can be performed simultaneously, or the process of step S4 can be performed after the process of step S5.

[0055] Next, in step S6, the driving control device 100 determines whether or not the own vehicle 1 after deceleration has stopped. When the driving control device 100 determines that the own vehicle 1 has not stopped, the driving control device 100 continues the determination in step S6 while continuously performing the deviation prevention control. On the other hand, when the driving control device 100 determines that the own vehicle 1 has stopped, in step S7, the second control unit 12 ends the deviation prevention control.

[0056] As described above, when the processor 10 of the driving control device 100 of the present embodiment determines that the second control unit 12 starts the deviation prevention control during the execution of the lane keeping control by the first control unit 11, the processor 10 ends the lane keeping control being executed, starts the deceleration control of the own vehicle 1, continuously performs the deviation prevention control until the own vehicle 1 stops by the deceleration control, and ends the deviation prevention control being executed when the own vehicle 1 stops by the deceleration control. Here, the case where the second control unit 12 starts the deviation prevention control during the execution of the lane keeping control by the first control unit 11 indicates that the own vehicle 1 deviates or is likely to deviate from the driving lane L because the function of the lane keeping control by the first control unit 11 does not fully function. That is, when the second control unit 12 starts the deviation prevention control during the execution of the lane keeping control by the first control unit 11, an abnormality may occur in the first control unit 11 (the first control unit 11 malfunctions). Therefore, the driving control device 100 can determine a situation in which an abnormality may occur in the execution function of the lane keeping control by determining whether or not the second control unit 12 starts the deviation prevention control during the execution of the lane keeping control by the first control unit 11, and controls the driving of the own vehicle according to the determination result. In addition, even when the second control unit 12 starts the deviation prevention control during the execution of the lane keeping control, that is, when an abnormality may occur in the execution function of the lane keeping control, the second control unit 12 continuously performs the deviation prevention control until the own vehicle 1 stops, and ends the deviation prevention control when the own vehicle 1 stops. Thereby, when an abnormality occurs in the function of executing the lane keeping control, the driving control device 100 can prevent the own vehicle 1 from deviating from the driving lane L and stop the own vehicle 1 to end the driving assistance control.

[0057] In addition, when the processor 10 of the driving control device 100 controls the driving of the own vehicle 1 in the hand - off mode, when it is determined that the second control unit 12 starts the deviation prevention control during the execution of the lane keeping control, the processor 10 outputs hand - holding request information for requesting the driver to hold the steering wheel 104a of the own vehicle 1. Thereby, when an abnormality occurs in the function of executing the lane keeping control, the driver can hold the steering wheel 104a and start manual driving during the period when the driving control device 100 continuously performs the deviation prevention control.

[0058] In addition, when the processor 10 of the driving control device 100 determines that the second control unit 12 starts the deviation prevention control during the execution of the lane keeping control, it determines that an abnormality has occurred in the first control unit 11 (a failure has occurred in the first control unit 11). Thereby, the driving control device 100 can efficiently determine whether there is an abnormality (failure) in the first control unit 11 without using an abnormality determination device with a complex structure.

[0059] In addition, before the second control unit 12 starts the deviation prevention control, the processor 10 of the driving control device 100 determines whether an abnormality has occurred in the second control unit 12 (whether a failure has occurred in the second control unit 12), and ends the driving assistance control when an abnormality occurs in the second control unit 12. Thereby, the driving control device 100 can prevent in advance a situation where it is impossible to correctly determine whether there is an abnormality in the first control unit 11 due to an abnormality occurring in the second control unit 12.

[0060] Reference Signs

[0061] 100: Driving control device

[0062] 1: This vehicle

[0063] 10: Processor

[0064] 11: First control unit

[0065] 12: Second control unit

[0066] 14: Abnormality determination unit

[0067] 15: Vehicle control unit

[0068] 104a: Steering wheel

[0069] L: Driving lane

Claims

1. A driving control method, which uses a processor to execute driving assistance control of the vehicle itself. Among them, the processor has: a first control unit that executes lane keeping control to maintain the lateral position of the vehicle itself at a specified position within the driving lane; a second control unit that executes deviation prevention control to prevent the vehicle itself from deviating from the driving lane. The processor executes the following processing: As a condition for the occurrence of an abnormality, it is determined whether the second control unit starts the deviation prevention control during the execution of the lane keeping control by the first control unit. When it is determined that the second control unit starts the deviation prevention control during the execution of the lane keeping control, end the currently executed lane keeping control, start the deceleration control of the vehicle itself, continue the deviation prevention control until the vehicle itself stops through the deceleration control, when the vehicle itself stops through the deceleration control, end the currently executed deviation prevention control.

2. The driving control method according to claim 1, wherein, when the processor controls the driving of the vehicle itself through the hand-off mode, when it is determined that the second control unit starts the deviation prevention control during the execution of the lane keeping control, it outputs hand-holding request information for requesting the driver to hold the steering wheel of the vehicle itself.

3. The driving control method according to claim 1 or 2, wherein, when the processor determines that the second control unit starts the deviation prevention control during the execution of the lane keeping control, it determines that an abnormality has occurred in the first control unit.

4. The driving control method according to claim 1 or 2, wherein, the processor executes the following processing: before the second control unit starts the deviation prevention control, determine whether the second control unit has an abnormality, when the second control unit has an abnormality, end the driving assistance control.

5. A driving control device that performs driving assistance control of the own vehicle, wherein, Comprising: a vehicle control unit, which has: a first control unit that executes lane keeping control to maintain the lateral position of the vehicle itself at a specified position within the driving lane; a second control unit that executes deviation prevention control to prevent the vehicle itself from deviating from the driving lane; an abnormality determination unit, as a condition for the occurrence of an abnormality, determines whether the second control unit starts the deviation prevention control during the execution of the lane keeping control by the first control unit, when the abnormality determination unit determines that the second control unit starts the deviation prevention control during the execution of the lane keeping control, the vehicle control unit executes the following processing: end the currently executed lane keeping control, start the deceleration control of the vehicle itself, continue the deviation prevention control until the vehicle itself stops through the deceleration control, when the vehicle itself stops through the deceleration control, end the currently executed deviation prevention control.

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