Vehicle control system and computer program

Abstract

The present invention provides a vehicle control device and computer program that can reduce brake shock. [Solution] The vehicle control device 10 includes a control unit 11 that performs stop control of a vehicle 1 that is driving by automatic driving, and the control unit calculates a stop determination timing at which the vehicle will stop if the vehicle is decelerating based on detected values ​​related to the vehicle's movement, sets a first stop flag from the off state to the on state at the stop determination timing, sets a second stop flag from the off state to the on state if it determines that the vehicle has the intention to stop based on the detected values, performs a stop hold pre-control to keep the vehicle in a stopped state if the first stop flag is on and the second stop flag is off, and does not perform the stop hold pre-control.

Description

Technical Field

[0001] The present invention relates to a vehicle control device that executes braking control and a computer program.

Background Art

[0002] In Patent Document 1, a technique has been proposed that can appropriately maintain the stopped state of a vehicle when the vehicle traveling by automatic driving decelerates and stops. The technique described in Patent Document 1 is configured to perform deceleration control based on a command to decelerate the vehicle when stopping the vehicle, and to stop the vehicle based on a stop command for maintaining the vehicle in a stopped state when the vehicle speed becomes a predetermined value or less.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Under predetermined conditions such as traffic jams, the vehicle may repeat deceleration and acceleration at extremely low speeds. Based on the technique described in Patent Document 1, when the vehicle travels at an extremely low speed under predetermined conditions, control to maintain the vehicle in a stopped state based on a stop command is executed, and there is a possibility that unnecessary braking shock may occur in the vehicle.

[0005] An object of the present invention is to provide a vehicle control device and a computer program capable of reducing braking shock based on braking force not required by the system during automatic driving.

Means for Solving the Problems

[0006] One aspect of the present invention is a vehicle control device comprising a control unit that performs stop control for a vehicle traveling by autonomous driving, wherein the control unit calculates a stop determination timing for when the vehicle is decelerating based on detected values ​​related to the vehicle's movement, sets a first stop flag from the off state to the on state at the stop determination timing, sets a second stop flag from the off state to the on state if it determines, based on the detected values, that the vehicle has an intention to stop, executes a stop-hold pre-control to keep the vehicle in a stopped state if both the first stop flag and the second stop flag are on, and does not execute the stop-hold pre-control if both the first stop flag and the second stop flag are off. [Effects of the Invention]

[0007] According to the present invention, it is possible to reduce brake shock caused by braking forces not requested by the system during autonomous driving. [Brief explanation of the drawing]

[0008] [Figure 1] This is a block diagram showing the configuration of a vehicle control device according to the embodiment. [Figure 2] This figure shows an example of the process for pre-controlling the stop and hold function. [Figure 3] This figure shows an example of the process for pre-controlling the stop and hold function. [Figure 4] This figure shows an example of the process for pre-controlling the stop and hold function. [Figure 5] This figure shows an example of the process for pre-controlling stop and hold based on a conventional method. [Figure 6] This flowchart shows the processing flow of the vehicle control method executed in the vehicle control device. [Modes for carrying out the invention]

[0009] As shown in Figure 1, Vehicle 1 is configured with a detection unit 2 and a vehicle control device 10 to enable autonomous driving. The detection unit 2 detects the environment around Vehicle 1. The detection unit 2 is composed of multiple devices depending on the application. The detected values ​​detected by the detection unit 2 are used to perform autonomous driving.

[0010] The detection unit 2 includes a camera 2A that captures images of the environment around the vehicle 1. The camera 2A captures images of the area around the vehicle 1 and outputs the captured data. In this embodiment, the camera 2A captures images of a predetermined area around the vehicle 1. The captured data from the camera 2A is used, for example, for autonomous driving of the vehicle 1 or as a drive recorder. The imaging range and imaging direction of the camera 2A may differ depending on the vehicle 1.

[0011] The detection unit 2 includes a lidar device 2B that detects three-dimensional data around the vehicle 1. The lidar device 2B periodically irradiates laser light in front of or around the vehicle 1 within the detection area and measures the reflected light from the target object. The lidar device 2B is configured to allow adjustment of the detection area. The lidar device 2B scans the laser light within the detection area and acquires measurement data. The lidar device 2B is configured to generate three-dimensional point cloud data around the vehicle 1 based on the measurement data.

[0012] The measurements from the LiDAR device 2B are used to detect other vehicles, pedestrians, bicycles, motorcycles, and other traffic participants around vehicle 1, as well as objects around vehicle 1. The LiDAR device 2B also detects road structures present in the road environment.

[0013] The detection unit 2 includes, for example, a radar device 2C that scans radar waves to detect objects present around the vehicle 1. The radar device 2C is configured to complement the detection of objects with the lidar device 2B. The radar device 2C detects the relative distance to an object by irradiating millimeter-wave radar waves in the detection area and receiving the reflected waves reflected from the object. The radar device 2C is configured to allow adjustment of the detection area.

[0014] The measured values of the radar device 2C are used to detect other vehicles, pedestrians, bicycles, motorcycles, and other traffic participants existing around the vehicle 1, as well as objects existing around the vehicle 1. The radar device 2C detects road structures existing in the road environment. The object recognition unit is constituted by the lidar device 2B and / or the radar device 2C.

[0015] The detection unit 2 includes a position sensor 2D that detects the current position of the vehicle 1. The position sensor 2D is, for example, a GPS (Global Positioning System) sensor or a GNSS (Global Navigation Satellite System) sensor. The position sensor 2D may mutually complement the position of the vehicle 1 by sensors used for autonomous navigation such as a gyro sensor and an acceleration sensor 2E.

[0016] The detection unit 2 includes an acceleration sensor 2E that detects the acceleration generated in the vehicle 1. The acceleration sensor 2E is constituted by, for example, a sensor that detects the acceleration in six-axis directions generated in the vehicle 1. The detection value detected by the acceleration sensor 2E is used to calculate the acceleration and speed of the vehicle 1.

[0017] The vehicle 1 includes a drive unit 5 that generates the power for traveling. The drive unit 5 is constituted by, for example, an internal combustion engine using fuel. The drive unit 5 may be constituted by an electric motor when the vehicle 1 is an electric vehicle. When the vehicle 1 is a hybrid vehicle, the drive unit 5 may be constituted by combining an internal combustion engine and an electric motor. The drive unit 5 is controlled by the vehicle control device 10 during the execution of autonomous driving, and the speed is adjusted.

[0018] The vehicle 1 includes a braking unit 6 for decelerating the vehicle speed and controlling it to a stop state. The braking unit 6 is constituted by, for example, a brake device that generates braking force. The braking unit 6 may be integrated with the drive unit 5 when the vehicle 1 is an electric vehicle. The braking unit 6 is controlled by the vehicle control device 10 during the execution of driving support.

[0019] Vehicle 1 includes a steering unit 7 for operating the traveling direction. The steering unit 7 is composed of a power steering device or the like that gives a steering angle to the steering wheel according to the steering operation. When the vehicle 1 is an electric vehicle, the steering unit 7 may be integrated with a driving unit 5 that variably controls the driving forces of the left and right driving wheels. The steering unit 7 is controlled by the vehicle control device 10 during the execution of driving assistance, and the steering angle is adjusted.

[0020] The vehicle control device 10 includes a control unit 11 that executes control related to the traveling of the vehicle 1. The control unit 11 integrally executes control such as the traveling, driving assistance, navigation, and communication via the network W of the vehicle 1 based on the detection values detected by the detection unit 2. The control unit 11 is composed of at least one hardware processor such as a CPU (Central Processing Unit). The control unit 11 may be realized by hardware (including circuitry) such as an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a GPU (Graphics Processing Unit), or may be realized by the cooperation of software and hardware.

[0021] The vehicle control device 10 includes a storage unit 12 that stores data and programs. The storage unit 12 is composed of a non-temporary storage medium such as a hard disk drive (HDD) or a solid state drive (SSD). In the storage unit 12, a computer program and data necessary for the control of the vehicle 1 are stored. The program may be stored in the storage unit 12 in advance, or may be stored in an externally connectable storage medium such as a DVD or a CD-ROM, and may be installed in the storage unit 12 when the storage medium is mounted on the drive device. The control unit 11 controls the driving unit 5, the braking unit 6, and the steering unit 7 based on the detection values detected by the detection unit 2, and executes an automatic driving control for automatically driving the vehicle?

[0022] As shown in Figure 2, the control unit 11 is configured to perform stop control on the vehicle 1 that is traveling by autonomous driving. The control unit 11 acquires a detected value from the detection unit 2. The control unit 11 calculates the vehicle speed (Vm / s) of the vehicle 1 based on the detected value from the acceleration sensor 2E, for example. If the vehicle 1 is decelerating, the control unit 11 performs stop control to stop the vehicle 1 from an extremely low speed range before the vehicle speed comes to a complete stop. The extremely low speed range is, for example, several tens of m / s or less. In the deceleration control to decelerate the vehicle 1, the control unit 11 acquires the required acceleration to decelerate the vehicle speed and controls the braking force of the braking unit 6 so that the vehicle speed becomes based on the required acceleration. The required acceleration is, for example, a command set in the driving plan based on autonomous driving.

[0023] The control unit 11 compares the vehicle speed with a threshold and determines whether the vehicle speed is below the threshold. The threshold is set, for example, based on the detection limit value of the acceleration sensor 2E. The threshold is, for example, a value of 50 cm / s (V1 m / s) or less. As shown in the figure, vehicle speeds below the threshold are not detected. Based on the detected values ​​related to the vehicle's movement, if the vehicle is decelerating, the control unit 11 calculates the stop determination timing at which the vehicle will stop after the vehicle speed falls below the threshold. For example, the control unit 11 counts a timer from the moment the vehicle speed reaches the threshold and sets the stop determination timing after a predetermined time.

[0024] The control unit 11 may, in setting the stop determination timing, calculate a second timing at which the vehicle 1 will stop in the future from a first timing at which the vehicle speed becomes a threshold, and set the stop determination timing at the calculated second timing. Alternatively, the control unit 11 may calculate the future vehicle speed based on the detected acceleration value immediately before the first timing and the image captured by the camera 2A, and set the stop determination timing at the timing when the vehicle speed approaches zero.

[0025] At the stop determination timing, the control unit 11 sets the first stop flag, a control variable for controlling the braking unit 6, from the normal off state to the on state. The control unit 11 determines whether or not to perform stop-hold pre-control to keep the vehicle stopped, taking into account not only the state of the first stop flag but also the state of the second stop flag, another control variable for controlling the braking unit 6. The second stop flag is, for example, a control variable for determining whether or not the vehicle 1 has the intention to stop. Based on the detected value, the control unit 11 determines whether or not the vehicle 1 has the intention to stop.

[0026] If the control unit 11 determines, based on the detected value, that a predetermined state related to the intention to stop exists, it sets the second stop flag to the ON state. The control unit 11 is configured to recognize the environment and objects around the vehicle 1 based on the image captured by the camera 2A, for example, by performing machine learning such as deep learning using image data as training data in advance.

[0027] The control unit 11 recognizes the state of the surroundings of the vehicle 1 based on the image captured by the camera 2A, and may determine that the vehicle 1 has the intention to stop if there is a predetermined state in which the vehicle 1 should stop. The predetermined state includes states in which there is a high probability that the vehicle 1 will stop in the future, such as stopping based on a signal indicating that it should stop, stopping based on the approach of other vehicles or traffic participants such as pedestrians, stopping based on traffic conditions, stopping due to parking, and stopping to follow a preceding vehicle.

[0028] The control unit 11 may determine that a predetermined state is in effect and that vehicle 1 has the intention to stop if a stop command exists for a device related to automatic driving, such as a navigation device (not shown) or a driving plan. The control unit 11 may determine that a predetermined state is in effect and that vehicle 1 has the intention to stop if another safety system, such as an automatic braking system, is activated and a stop command exists. The control unit 11 may determine that vehicle 1 has the intention to stop if another safety system is activated and the target vehicle speed is set to 0 km / h or less. The control unit 11 may determine that vehicle 1 has the intention to stop if another safety system is activated and the required acceleration is set to a large negative value after vehicle 1 has stopped.

[0029] If the control unit 11 determines that the vehicle 1 has the intention to stop, it sets the second stop flag from the normal off state to the on state. If the first stop flag is on and the second stop flag is on, the control unit 11 performs stop-hold pre-control to hold the vehicle 1 in a stopped state. When the control unit 11 performs stop-hold pre-control, it controls the braking device of the braking unit 6 at the stop determination timing to maintain the vehicle in a stopped state.

[0030] As shown in Figure 3, the control unit 11 maintains the second stop flag in the off state if it determines, based on the detected value, that a predetermined state does not exist. The control unit 11 maintains the second stop flag in the off state if it determines, based on the detected value, that a predetermined state will not exist in the future, such as when vehicle 1 is making a U-turn or when the preceding vehicle has started moving from a stopped state.

[0031] As shown in Figure 4, if the control unit 11 determines that a predetermined state currently existing will disappear in the future, it may reset the second stop flag, which was set to the ON state, to the OFF state. As shown in the figure, the control unit 11 monitors the vehicle speed during deceleration in automatic driving, and when the vehicle speed falls below a threshold, it calculates the stop determination timing and sets the first stop flag to the ON state at the stop determination timing. Based on the image captured by the camera 2A, the control unit 11 recognizes the state around the vehicle 1, and if it determines that there is no predetermined state in which the vehicle 1 should stop, it sets the second stop flag from the ON state to the OFF state.

[0032] The control unit 11 does not perform stop-hold pre-control when the first stop flag is on and the second stop flag is off. According to the above process, when vehicle 1 is following a preceding vehicle in the extremely low-speed range, the control unit 11 does not perform stop-hold pre-control, so vehicle 1 continues to travel at extremely low speeds without generating brake shocks.

[0033] Figure 5 shows a conventional method for performing stop-hold pre-control using only the first stop flag without using the second stop flag. When stop-hold pre-control is performed using only the first stop flag, if the vehicle speed is below the threshold, the first stop flag remains in the ON state, which means that the vehicle may repeatedly receive stop-hold pre-control interventions, potentially causing brake shocks each time. In contrast, the vehicle control device 10 can suppress the occurrence of unnecessary brake shocks even when the vehicle speed is below the threshold by performing processing based on both the first and second stop flags.

[0034] Figure 6 shows the processing flow of the vehicle control method executed in the vehicle control device 10. The vehicle control method is executed based on a computer program installed in the computer mounted on the vehicle control device 10. The computer program causes the control unit 11 (processor) of the computer mounted on the vehicle control device 10 to perform the following processes. The control unit 11 acquires detection values ​​related to the movement of the vehicle detected by the detection unit 2 (S100). Based on the detection values, the control unit 11 calculates the stop determination timing if the vehicle is decelerating (S102). At the stop determination timing, the control unit 11 sets the first stop flag from the off state to the on state (S104).

[0035] The control unit 11 determines, based on the detected value, whether or not the vehicle has the intention to stop (S106). If the control unit 11 determines that the vehicle 1 has the intention to stop, it sets the second stop flag from the off state to the on state (S108). If the first stop flag is on and the second stop flag is on, the control unit 11 performs stop-hold pre-control to keep the vehicle in a stopped state (S110). If the control unit 11 determines in S106 that the vehicle 1 does not have the intention to stop, it maintains the second stop flag in the off state (S112). If the first stop flag is on and the second stop flag is off, the control unit 11 does not perform stop-hold pre-control (S114).

[0036] As described above, the vehicle control device 10 can reduce brake shocks caused by braking forces not requested by the system when the vehicle 1 is traveling at an extremely low speed during autonomous driving. The vehicle control device 10 can suppress the occurrence of unnecessary brake shocks when the vehicle 1 is traveling at an extremely low speed during autonomous driving by determining the execution of stop-hold pre-control based not only on the state of the first stop flag but also on the state of the second stop flag. The vehicle control device 10 can suppress the occurrence of unnecessary brake shocks when the vehicle 1 is following a preceding vehicle at an extremely low speed during autonomous driving.

[0037] In the embodiments described above, the computer programs executed in each configuration of the vehicle control device 10 may be provided in the form of being recorded on a computer-readable portable recording medium such as a semiconductor memory, a magnetic recording medium, or an optical recording medium. The computer programs may also be provided as a program product. [Explanation of Symbols]

[0038] 1 Vehicle, 2 Detection unit, 2A Camera, 2B LiDAR device, 2C Radar device, 2D Position sensor, 2E Acceleration sensor, 5 Drive unit, 6 Braking unit, 7 Steering unit, 10 Vehicle control device, 11 Control unit, 12 Memory unit

Claims

1. It includes a control unit that performs stopping control for vehicles operating under autonomous driving conditions, The control unit, Based on the detected values ​​regarding the vehicle's movement, if the vehicle is decelerating, a stop determination timing for the vehicle to stop is calculated, and at the stop determination timing, the first stop flag is set from the off state to the on state. If it is determined that the vehicle has the intention to stop based on the detected value, the second stop flag is set from the off state to the on state. If the first stop flag is in the ON state and the second stop flag is in the ON state, a stop-hold pre-control is performed to keep the vehicle in a stopped state. If the first stop flag is in the ON state and the second stop flag is in the OFF state, the stop hold pre-control is not performed. Vehicle control system.

2. The control unit, If it is determined that a predetermined state related to the intention to stop exists based on the detected value, the second stop flag is set to the ON state. The vehicle control device according to claim 1.

3. The control unit, If it is determined that the predetermined state does not exist based on the detected value, the second stop flag is kept in the off state. The vehicle control device according to claim 2.

4. The control unit, When the aforementioned stop-hold pre-control is performed, the braking device for decelerating the vehicle is controlled at the stop determination timing to bring the vehicle to the stopped state. The vehicle control device according to claim 1.

5. A computer program installed on a computer mounted in a vehicle control system that performs stopping control for a vehicle operating under autonomous driving conditions, Based on the detected values ​​regarding the vehicle's movement, if the vehicle is decelerating, a stop determination timing for the vehicle to stop is calculated, and at the stop determination timing, the first stop flag is set from the off state to the on state. If it is determined that the vehicle has the intention to stop based on the detected value, the second stop flag is set from the off state to the on state. If the first stop flag is in the ON state and the second stop flag is in the ON state, a stop-hold pre-control is performed to keep the vehicle in a stopped state. If the first stop flag is in the ON state and the second stop flag is in the OFF state, the computer is instructed to perform a process that does not execute the stop hold pre-control. Computer program.

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