Vehicle control system

Abstract

To provide a vehicle control system capable of more appropriately transmitting curve information to a driver.SOLUTION: A vehicle control system 1 includes a notification timing determination part 12, a vehicle speed control part 13, and a steering control part 14. The notification timing determination part 12 determines whether to reach preset driver notification timing on the basis of a distance between a vehicle and a curve. The vehicle speed control part 13 executes inertial force change sensory control to a driver by suppressing acceleration of the vehicle or increasing deceleration of the vehicle in the case that the notification timing determination part 12 determines that the driver notification time is reached. The steering control part 14 executes rotation return behavior control corresponding to a curve turning direction within a dead zone of vehicle steering in the case that the notification timing determination part 12 determines that the driver notification timing is reached.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to vehicle control systems. [Background technology]

[0002] Japanese Patent Laid-Open Publication No. 6-36187 is known as a technical document relating to a conventional vehicle control system. Japanese Patent Laid-Open Publication No. 6-36187 discloses a technology for calculating the vehicle deceleration required for the vehicle to pass a corner on a road, adjusting the vehicle speed when the deceleration exceeds a threshold, and outputting a warning to the driver by displaying an image on a display or by an acoustic means such as a buzzer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 6-36187 Summary of the Invention [Problem to be solved by the invention]

[0004] Various information is provided to the driver of a vehicle that is performing driving assistance or autonomous driving by displaying images or outputting audio. When information is provided by displaying images, the driver must shift his or her gaze from the front of the vehicle. Even when information is displayed by a head-up display (HUD), the driver must shift the focus of his or her gaze, which diverts attention from the front of the vehicle. Audio notifications may also be annoying to the driver.

[0005] An object of the present disclosure is to provide a vehicle control system that can more appropriately convey curve information to a driver. [Means for solving the problem]

[0006] The vehicle control system disclosed herein is a vehicle control system that recognizes curves ahead of the vehicle and controls the vehicle speed around the curve, and includes a notification timing determination unit that determines whether a preset driver notification timing has been reached based on the distance between the vehicle and the curve, a vehicle speed control unit that, when the notification timing determination unit determines that the driver notification timing has been reached, executes inertia force change sensation control for the driver by suppressing the acceleration of the vehicle or increasing the deceleration of the vehicle, and a steering control unit that, when the notification timing determination unit determines that the driver notification timing has been reached, executes rotation return behavior control according to the bending direction of the curve within the range of the vehicle's steering dead zone. Effect of the Invention

[0007] According to the present disclosure, it is possible to provide a vehicle control system that can more appropriately convey curve information to a driver. [Brief description of the drawings]

[0008] [Figure 1] 1 is a block diagram of a vehicle control system according to an embodiment. [Diagram 2] FIG. 2 is a plan view showing a vehicle before entering a curve. [Diagram 3] FIG. 13 is a schematic diagram showing inertial force change sensation control. [Figure 4] 4 is a flowchart showing a process performed by the vehicle control system. [Diagram 5] 10 is a flowchart showing a process performed by a vehicle control system according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Fig. 1 is a block diagram of a vehicle control system. As shown in Fig. 1, the vehicle control system 1 includes a forward camera 2, a GNSS [Global Navigation Satellite System] signal receiver 3, a map database 4, a drive actuator 5, a brake actuator 6, a steering actuator 7, and an ECU [Electronic Control Unit] 10. The vehicle may be driven autonomously or by driving assistance.

[0010] The front camera 2 is provided inside the vehicle cabin. For example, the front camera 2 is provided behind the windshield of the vehicle. The front camera 2 captures an image in front of the vehicle. For example, the front camera 2 is a monocular camera. The front camera 2 may be a stereo camera. The front camera 2 transmits the captured image to the ECU 10.

[0011] The GNSS signal receiver 3 receives signals from positioning satellites to measure the position of the vehicle (for example, the latitude and longitude of the vehicle). The GNSS signal receiver 3 transmits vehicle position information to the ECU .

[0012] The map database 4 stores map information. The map information includes, for example, information on roads and intersections. The map information includes, for example, road position information (position information for each lane), road shape information (for example, types of curves and straight sections, curvature, etc.), and position information of intersections and branching points. The map database 4 is formed in a server capable of communicating with the vehicle. The map database 4 may be formed in, for example, a storage device such as a HDD [Hard Disk Drive] mounted on the vehicle.

[0013] The drive actuator 5 controls the drive force of the vehicle in response to a control signal from the ECU 10. Specifically, the drive actuator 5 controls the amount of air supplied to the engine (throttle opening) to control the drive force of the vehicle. If the vehicle is a hybrid vehicle (HEV: Hybrid Electric Vehicle), in addition to the amount of air supplied to the engine, a control signal from the ECU 10 is input to a motor serving as a power source to control the drive force. If the vehicle is an electric vehicle (BEV: Battery Electric Vehicle), a control signal from the ECU 10 is input to a motor serving as a power source to control the drive force. In these cases, the motor serving as a power source constitutes the drive actuator 5.

[0014] The brake actuator 6 controls the braking force of the vehicle in response to a control signal from the ECU 10. Specifically, the brake actuator 6 controls a brake system in response to a control signal from the ECU 10, and controls the braking force applied to the wheels of the vehicle. As the brake system, for example, a hydraulic brake system can be used.

[0015] The steering actuator 7 controls the steering torque or steering angle of the vehicle in response to a control signal from the ECU 10. Specifically, the steering actuator 7 controls the drive of an assist motor that controls the steering torque or steering angle of the electric power steering system in response to a control signal from the ECU 10.

[0016] The ECU 10 is an electronic control unit having a central processing unit (CPU) and a storage unit such as a read only memory (ROM) or a random access memory (RAM). In the ECU 10, for example, various functions are realized by the CPU executing a program stored in the storage unit. The ECU 10 is provided in, for example, a vehicle.

[0017] The ECU 10 includes, as functional components, a curve recognition unit 11, a notification timing determination unit 12, a vehicle speed control unit 13, and a steering control unit 14. The ECU 10 recognizes a curve ahead of the vehicle and executes vehicle speed control for the curve. Fig. 2 is a plan view showing a vehicle before entering the curve. As shown in Fig. 2, in this embodiment, the ECU 10 executes vehicle speed control, etc., at a predetermined timing based on a distance D between the vehicle M and the curve C (for example, the entrance of the curve C).

[0018] Specifically, the curve recognition unit 11 recognizes whether or not a curve C exists ahead of the vehicle M based on, for example, position information and map information of the vehicle M. The curve recognition unit 11 may recognize whether or not a curve C exists ahead of the vehicle M based on, for example, an image captured by the front camera 2.

[0019] When a curve C is present ahead of the vehicle M, the curve recognition unit 11 recognizes the bending direction and the curvature radius of the curve C. The curve recognition unit 11 recognizes the bending direction and the curvature radius of the curve C, for example, based on map information in a map database 4. The curve recognition unit 11 may recognize the bending direction and the curvature radius of the curve C, for example, based on an image captured by the front camera 2.

[0020] The notification timing determination unit 12 determines whether a preset driver notification timing has been reached based on the distance D between the vehicle M and the curve C. The entrance of the curve C may be, for example, a point where the curvature of the road is equal to or greater than a predetermined curvature threshold. The entrance of the curve C may be, for example, a boundary between a straight region and a curved region of the road.

[0021] The driver notification timing is the timing at which the vehicle control system 1 notifies the driver that it recognizes the curve C ahead of the vehicle M. The driver notification timing can be, for example, a threshold value corresponding to the remaining time until the vehicle M reaches the curve C. The driver notification timing is, for example, about several seconds.

[0022] The notification timing determination unit 12 calculates the remaining time until the vehicle M reaches the curve C based on the distance D and the vehicle speed of the vehicle M. If the remaining time is equal to or less than the driver notification timing, the notification timing determination unit 12 determines that the driver notification timing has been reached. If the remaining time is longer than the driver notification timing, the notification timing determination unit 12 does not determine that the driver notification timing has been reached. Note that the notification timing determination unit 12 may determine whether or not the driver notification timing has been reached based only on the distance D between the vehicle M and the entrance of the curve C. In this case, the driver notification timing is a threshold value corresponding to the distance D between the vehicle M and the entrance of the curve C.

[0023] When the notification timing determination unit 12 determines that the driver notification timing has arrived, the vehicle speed control unit 13 executes inertial force change sensation control for the driver by suppressing the acceleration of the vehicle M or increasing the deceleration of the vehicle M. The inertial force change sensation control is a control that makes the driver feel a change in the inertial force of the vehicle M in order to notify the driver that the vehicle control system 1 recognizes the curve C ahead of the vehicle M.

[0024] 3 is a schematic diagram showing the inertial force change sensation control. As shown in FIG 3, the vehicle speed control unit 13 reduces the acceleration of the vehicle M from a first timing T1 (e.g., a timing at which the driver is notified) and maintains the low acceleration state until a second timing T2 (e.g., a timing at which the vehicle M enters a curve C).

[0025] 3(a), when the vehicle M is traveling steadily, that is, when the acceleration of the vehicle M is zero, the vehicle speed control unit 13 increases the absolute value of the acceleration of the vehicle M (increases the deceleration) while changing the direction of the acceleration of the vehicle M to the opposite direction to the traveling direction of the vehicle M. In this case, the vehicle M continues to decelerate from the first timing T1 to the second timing T2. The vehicle speed control unit 13 applies a braking force to the wheels of the vehicle M, for example, by transmitting a control signal to the brake actuator 6.

[0026] 3(b), when the vehicle M is accelerating, that is, when the direction of the acceleration of the vehicle M is in the traveling direction of the vehicle M, the vehicle speed control unit 13 reduces the absolute value of the acceleration of the vehicle M (suppression of acceleration). In this case, the vehicle M continues to accelerate in a low acceleration state between the first timing T1 and the second timing T2. For example, the vehicle speed control unit 13 transmits a control signal to the drive actuator 5 to release the drive of the vehicle M, and transmits a control signal to the brake actuator 6 to apply a braking force to the wheels of the vehicle M.

[0027] 3(c), when the vehicle M is decelerating, that is, when the direction of the acceleration of the vehicle M is opposite to the traveling direction of the vehicle M, the vehicle speed control unit 13 increases the absolute value of the acceleration of the vehicle M (increases the deceleration). In this case, the vehicle M continues to decelerate in a high acceleration state from the first timing T1 to the second timing T2. The vehicle speed control unit 13 increases the braking force applied to the wheels of the vehicle M, for example, by sending a control signal to the brake actuator 6.

[0028] When the vehicle speed of the vehicle M after execution of the inertial force change sensation control is higher than the curve entry vehicle speed, the vehicle speed control unit 13 executes curve entry deceleration control before entering the curve C. The curve entry vehicle speed is a threshold value set in advance for the entry of the vehicle M into the curve C. The smaller the radius of curvature of the curve C (the sharper the curve C), the smaller the curve entry vehicle speed may be. As the radius of curvature of the curve C, the maximum value at the curve C may be used, the average value at the curve C may be used, or a value stored in association with the curve C in the map information may be used.

[0029] When the vehicle speed of the vehicle M after execution of the inertial force change sensation control is higher than the curve entry vehicle speed, the vehicle speed control unit 13 makes the vehicle speed of the vehicle M equal to or lower than the curve entry vehicle speed. The vehicle speed control unit 13 applies a braking force to the wheels of the vehicle M by sending a control signal to the brake actuator 6.

[0030] When the notification timing determination unit 12 determines that the driver notification timing has arrived, the steering control unit 14 executes rotation return behavior control according to the bending direction of the curve C within the range of the dead zone of the steering of the vehicle M. The dead zone is a dead zone in which the rotation of the steering wheel is not reflected in the traveling of the vehicle M. The rotation return behavior control is a control for rotating the steering wheel or returning the position of the steering wheel.

[0031] The steering control unit 14 rotates the steering wheel of the vehicle M in the bending direction of the curve C by transmitting a control signal to the steering actuator 7. In the example shown in Fig. 2, since the curve C curves to the left, the steering control unit 14 rotates the steering wheel of the vehicle M to the left within the range of the dead zone. After rotating the steering wheel of the vehicle M, the steering control unit 14 returns the steering wheel of the vehicle M to its original position.

[0032] The steering control unit 14 may change the rotation angle of the steering wheel in the rotation return behavior control in accordance with the radius of curvature of the curve C. The steering control unit 14 may set the rotation angle of the steering wheel in the rotation return behavior control to a larger angle as the radius of curvature of the curve C is smaller.

[0033] The steering control unit 14 may set the rotation angle of the steering wheel in the rotation return behavior control to a larger angle when the driver is not gripping the steering wheel compared to when the driver is gripping the steering wheel. The steering control unit 14 may determine whether the driver is gripping the steering wheel based on, for example, a touch sensor provided on the steering wheel or an image captured by a driver monitor camera. The steering control unit 14 may also repeat the rotation and return of the steering wheel of the vehicle M a predetermined number of times.

[0034] The steering control unit 14 executes the rotation return behavior control when a first set time has elapsed since the execution of the inertial force change sensation control. The first set time is a time set in advance. The shorter the driver notification timing is, the shorter the first set time may be. The smaller the curvature radius of the curve C is, the shorter the first set time may be.

[0035] Next, a description will be given of the processing performed by the vehicle control system 1. FIG 4 is a flowchart showing the processing performed by the vehicle control system 1.

[0036] 4, the ECU 10 determines whether or not the driver notification timing has arrived in step S1. If the ECU 10 determines that the driver notification timing has arrived in step S1 (step S1: YES), the ECU 10 executes inertial force change sensation control in step S2. If the ECU 10 does not determine that the driver notification timing has arrived in step S1 (step S1: NO), the ECU 10 ends the current process.

[0037] In step S3, the ECU 10 determines whether or not a first set time has elapsed since the inertial force change sensation control. If it is determined in step S3 that the first set time has elapsed (step S3: YES), the ECU 10 executes the rotation return behavior control in step S4. If it is not determined in step S3 that the first set time has elapsed (step S3: NO), the ECU 10 again determines whether or not the first set time has elapsed.

[0038] In step S5, the ECU 10 judges whether the vehicle speed is higher than the curve entry vehicle speed. If the ECU 10 judges in step S5 that the vehicle speed is higher than the curve entry vehicle speed (step S5: YES), the ECU 10 executes the curve entry deceleration control in step S6. If the ECU 10 does not judge in step S5 that the vehicle speed is higher than the curve entry vehicle speed (step S5: NO), the ECU 10 ends this processing.

[0039] As described above, when it is determined that the timing for notifying the driver has arrived based on the distance D between the vehicle M and the curve C, the vehicle control system 1 executes the inertial force change sensation control and the steering rotation return behavior control according to the bending direction of the curve C, thereby notifying the driver that the vehicle control system 1 recognizes the curve C ahead of the vehicle by a means other than a screen display or audio output. Therefore, the vehicle control system 1 can more appropriately convey the curve information to the driver.

[0040] The steering control unit 14 executes the rotation return behavior control when the first set time has elapsed since the execution of the inertial force change sensation control. This makes it easier for the driver to recognize that the vehicle control system 1 recognizes the curve C ahead of the vehicle, compared to a case in which the inertial force change sensation control and the rotation return behavior control are executed at timings unrelated to each other.

[0041] When the vehicle speed of the vehicle M after the execution of the inertial force change sensation control is higher than a curve entry vehicle speed preset for entering the curve, the vehicle speed control unit 13 executes the curve entry deceleration control before entering the curve. This allows the vehicle M to smoothly enter the curve.

[0042] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments. The present disclosure can be implemented in various forms including the above-described embodiments and various modifications and improvements based on the knowledge of those skilled in the art.

[0043] 5 is a flowchart showing a process performed by a vehicle control system according to a modified example. The ECU 10 may execute the inertial force change sensation control after executing the rotation return behavior control. The vehicle speed control unit 13 may execute the inertial force change sensation control when a second set time has elapsed since the execution of the rotation return behavior control.

[0044] Specifically, as shown in Fig. 5, in step S10, the ECU 10 determines whether or not the driver notification timing has arrived, similar to step S1 in the embodiment. If it is determined in step S10 that the driver notification timing has arrived (step S10: YES), the ECU 10 executes the rotation return behavior control in step S20. If it is not determined in step S10 that the driver notification timing has arrived (step S10: NO), the ECU 10 ends this processing.

[0045] In step S30, the ECU 10 determines whether a second set time has elapsed since the rotation return behavior control. The second set time is a time set in advance. The shorter the driver notification timing, the shorter the second set time may be. The smaller the radius of curvature of the curve C, the shorter the second set time may be. The second set time may be the same as the first set time, or may be different from the first set time.

[0046] If it is determined in step S30 that the second set time has elapsed (step S30: YES), the ECU 10 executes inertial force change sensation control in step S40. If it is not determined in step S30 that the second set time has elapsed (step S30: NO), the ECU 10 again determines whether the second set time has elapsed.

[0047] In step S50, the ECU 10 determines whether the vehicle speed is higher than the curve entry vehicle speed, similar to step S5 in the embodiment. If the ECU 10 determines in step S50 that the vehicle speed is higher than the curve entry vehicle speed (step S50: YES), the ECU 10 executes the curve entry deceleration control in step S60, similar to step S6 in the embodiment. If the ECU 10 does not determine in step S50 that the vehicle speed is higher than the curve entry vehicle speed (step S50: NO), the ECU 10 ends this processing.

[0048] The ECU 10 may not execute step S3. That is, the ECU 10 may execute the rotation return behavior control regardless of whether the first set time has elapsed after executing the inertial force change sensation control. The ECU 10 may not execute step S30. That is, the ECU 10 may execute the inertial force change sensation control regardless of whether the second set time has elapsed after executing the rotation return behavior control. The ECU 10 may execute the inertial force change sensation control and the rotation return behavior control simultaneously.

[0049] The ECU 10 may not execute steps S5 and S6, and the ECU 10 may not execute steps S50 and S60.

[0050] The vehicle control system 1 of the present disclosure is different from general speed management control that accelerates and decelerates the vehicle so as to pass through a curve at a speed set according to the curvature radius of the curve ahead of the vehicle. The vehicle control system 1 of the present disclosure has a feature that notifies the driver that the vehicle control system 1 recognizes the curve C ahead of the vehicle by a method other than a screen display or audio output. [Explanation of symbols]

[0051] 1...vehicle control system, 12...notification timing determination unit, 13...vehicle speed control unit, 14...steering control unit, C...curve, M...vehicle.

Claims

1. A vehicle control system that recognizes a curve ahead of a vehicle and controls the vehicle speed around the curve, a notification timing determination unit that determines whether a preset driver notification timing has been reached based on a distance between the vehicle and the curve; a vehicle speed control unit that executes an inertial force change sensation control for the driver by suppressing an acceleration of the vehicle or increasing a deceleration of the vehicle when the notification timing determination unit determines that the driver notification timing has been reached; and a steering control unit that executes a rotation recovery behavior control according to a direction of turning of the curve within a dead zone of a steering of the vehicle when the notification timing determination unit determines that the driver notification timing has been reached; A vehicle control system comprising:

2. The vehicle control system according to claim 1 , wherein the steering control unit executes the rotation return behavior control when a first set time has elapsed since the inertia force change sensation control was executed.

3. The vehicle control system according to claim 1 , wherein the vehicle speed control unit executes the inertia force change sensation control when a second set time has elapsed since the execution of the rotation return behavior control.

4. The vehicle control system according to any one of claims 1 to 3, wherein the vehicle speed control unit executes a curve entry deceleration control before entering the curve when the vehicle speed of the vehicle after executing the inertia force change sensation control is higher than a curve entry vehicle speed preset for entering the curve.

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