Driver assistance systems

Abstract

To provide a driving assistance system capable of preventing traveling control in a state where a driver does not hold a steering wheel from being restricted more than necessary.SOLUTION: A driving assistance system 1 is a system capable of continuing travel control of a vehicle V in a hands-off manner. The driving assistance system 1 calculates arrival time until the vehicle V arrives at a caution area, and permits the travel control in a hands-off manner when the arrival time is longer than set hands-off permission time.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] One aspect of the present invention relates to a driving support system.

Background Art

[0002] As a technology related to a driving support system, for example, in Patent Document 1, when traffic congestion around the host vehicle is grasped within an area where autonomous driving is possible, autonomous driving by autonomous driving control without the obligation of the driver to monitor the surroundings and the obligation to hold the steering wheel in the host vehicle becomes possible. A technology is disclosed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in a driving support system capable of continuing driving control such as lane keeping control in a state where the driver of the vehicle does not hold the steering wheel (hereinafter also referred to as "hands-off"), when the vehicle is within a certain distance from a caution area such as an intersection, for example, in order to ensure safety, it may be considered not to permit hands-off driving control. In such a driving support system, when the vehicle approaches a caution area, for example, in a situation where the traffic flow is slow, the driving control may be restricted even though there is still sufficient time to continue hands-off driving control.

[0005] Therefore, one aspect of the present invention aims to provide a driving support system that can suppress being restricted more than necessary in driving control in a state where the driver does not hold the steering wheel.

Means for Solving the Problems

[0006] (1) A driving assistance system according to one aspect of the present invention is a driving assistance system that can continue to control the driving of a vehicle when the driver of the vehicle is not holding the steering wheel, and calculates the time it will take for the vehicle to reach a caution area, and if the time to reach the area is greater than the set hands-off permission time, it permits driving control when the driver is not holding the steering wheel.

[0007] This driver assistance system allows for hands-off driving control based on the time it takes for the vehicle to reach a high-risk area. Therefore, for example, when the vehicle approaches a high-risk area in slow traffic conditions, it is possible to prevent hands-off driving control from being unnecessarily restricted.

[0008] (2) In the driving assistance system described in (1) above, the area requiring attention may be at least one of the following: intersections, construction zones, sections including accident sites, and sections where accidents frequently occur. In this case, at least one of the following can be considered as the area requiring attention: intersections, construction zones, sections including accident sites, and sections where accidents frequently occur.

[0009] (3) In the driving assistance systems described in (1) or (2) above, the hands-off permission time may be determined according to the type of area requiring attention. In this case, the above effect can be achieved by preventing hands-off driving control from being unnecessarily restricted according to the type of area requiring attention.

[0010] (4) A driving assistance system described in any of (1) to (3) above may not permit driving control when the driver is not holding the steering wheel if the arrival time is less than or equal to the hands-off permitted time. In this case, if the arrival time is less than or equal to the hands-off permitted time and the vehicle is about to arrive at, for example, a caution area, the driving control can be restricted so that hands-off driving control is not performed.

[0011] (5) If the driver assistance system described in (4) above does not permit driving control when the driver is not holding the steering wheel, it may request the driver to drive while holding the steering wheel. This allows the driver to be prompted to drive hands-on when hands-off driving control is not permitted. [Effects of the Invention]

[0012] According to one aspect of the present invention, it is possible to provide a driver assistance system that can prevent excessive restrictions on driving control when the driver is not holding the steering wheel. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 is a block diagram showing the configuration of a driver assistance system according to an embodiment. [Figure 2] Figure 2 is a flowchart showing the processing of the driver assistance system in Figure 1. [Figure 3] Figure 3(a) is a schematic diagram showing an example of the permitted range of hands-off driving by the driver assistance system in the comparative example. Figure 3(b) is a schematic diagram showing an example of the permitted range of hands-off driving by the driver assistance system in Figure 1. [Modes for carrying out the invention]

[0014] The embodiments will be described in detail below with reference to the attached drawings. In the description of the drawings, the same or equivalent elements will be denoted by the same reference numeral, and redundant descriptions will be omitted.

[0015] As shown in Figure 1, the driver assistance system 1 according to this embodiment is installed in a vehicle V. The vehicle V may be a passenger car or a cargo vehicle. The vehicle V can accommodate one or more occupants. The vehicle V may be an autonomous driving vehicle capable of autonomous driving. The vehicle V may also be capable of manual driving by a driver.

[0016] The driver assistance system 1 is a system that can continue to control the driving of vehicle V even when the driver of vehicle V is not holding the steering wheel (hereinafter also referred to as hands-off). The driving control is, for example, lane keeping assist (LKA) which automatically steers vehicle V to prevent it from deviating from the driving lane in which it is traveling. The driving control is not particularly limited and may be other driving assistance-related driving control. The driver assistance system 1 is equipped with an ECU (Electronic Control Unit) 10.

[0017] The ECU10 is an electronic control unit that includes a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), and other components. The ECU10 performs various functions, for example, by loading a program stored in ROM into RAM and then executing the program loaded into RAM using the CPU. Some of the functions of the ECU10 may be performed on a server capable of communicating with the vehicle V. The ECU10 may be composed of multiple electronic units. An internal sensor 2, an external sensor 3, a navigation system 4, an HMI 5, and an actuator 6 are connected to the ECU10.

[0018] Internal sensor 2 is a detection device that detects the driving state of vehicle V. Internal sensor 2 includes a vehicle speed sensor, an acceleration sensor, and a yaw rate sensor. The vehicle speed sensor is a detector that detects the speed of vehicle V. For example, a wheel speed sensor that detects the rotational speed of the wheels can be used as the vehicle speed sensor. The vehicle speed sensor transmits the detected vehicle speed information to the ECU 10. The acceleration sensor is a detector that detects the acceleration of vehicle V. For example, the acceleration sensor transmits the acceleration information of vehicle V to the ECU 10. The yaw rate sensor is a detector that detects the yaw rate (rotational angular velocity) of vehicle V around the vertical axis of the center of gravity of vehicle V. For example, a gyro sensor can be used as the yaw rate sensor. The yaw rate sensor transmits the detected yaw rate information of vehicle V to the ECU 10.

[0019] The external sensor 3 is a detection device that detects the surrounding environment of the vehicle V. The external sensor 3 includes a camera and a radar sensor. The camera is provided, for example, on the back side of the front glass of the vehicle V and images the front of the vehicle V. The camera may be provided on the back and sides of the vehicle V. The camera transmits the imaging information around the vehicle V to the ECU 10. The camera may be a monocular camera or a stereo camera. The radar sensor is a detection device that uses radio waves (e.g., millimeter waves) or light to detect obstacles around the vehicle V. The radar sensor includes, for example, a millimeter wave radar or a lidar. The radar sensor transmits the detected obstacle information to the ECU 10.

[0020] The navigation system 4 is a system that guides the driver of the vehicle V to a preset destination. The navigation system 4 recognizes the driving road and driving lane on which the vehicle V travels based on the position of the vehicle V measured by the GPS receiver and the map information in the map database. The navigation system 4 calculates a target route from the position of the vehicle V to the destination and guides the driver with respect to the target route using the HMI 5.

[0021] The HMI 5 is an interface for inputting and outputting information to and from the driver. The HMI 5 includes, for example, a display and a speaker visible to the driver. The HMI 5 performs image output on the display and voice output from the speaker according to a control signal from the ECU 10. The HMI 5 may include a HUD (Head Up Display).

[0022] The actuator 6 is a device used for controlling the vehicle V. The actuator 6 includes at least a drive actuator, a brake actuator, and a steering actuator. The drive actuator controls an engine and / or a motor as a power source in response to a control signal from the ECU 10, and controls the driving force of the vehicle V. The brake actuator controls the brake system in response to a control signal from the ECU 10, and controls the braking force applied to the wheels of the vehicle V. The steering actuator controls the driving of an assist motor that controls the steering torque in an electric power steering system in response to a control signal from the ECU 10. Thereby, the steering actuator controls the steering torque of the vehicle V.

[0023] The ECU 10 executes the running control of the vehicle V. For example, when performing lane keeping control as the running control, the ECU 10 executes steering control to make the vehicle V run so as to maintain the lane based on the detection results of the internal sensor 2 and the external sensor 3.

[0024] The ECU 10 of the present embodiment calculates the arrival time T until the vehicle V reaches the attention required area. The attention required area is an area that requires attention. The attention required area is an area with low safety. The attention required area is at least any one of an intersection, a construction section, a section including an accident site, and a section with a high frequency of accident occurrence. For example, an intersection, a construction section, a section including an accident site, and a section with a high frequency of accident occurrence may be preset based on the map database of the navigation system 4 and stored in the ECU 10.

[0025] Specifically, the ECU 10 calculates the arrival distance X to the attention required area based on the map database of the navigation system 4 and the detection result of the external sensor 3. The ECU 10 calculates the traffic flow Y based on the detection result of the internal sensor 2 and traffic-related information (for example, traffic-related information that can be obtained via VICS [Vehicle Information and Communication System] (registered trademark)). The arrival time T is calculated from the calculated arrival distance X and traffic flow Y by the following formula. T(s) = X(m) / Y(m / s)

[0026] As shown below, the ECU10 permits hands-off driving control when the arrival time T is greater than the set hands-off permission time S, and disallows hands-off driving control when the arrival time T is less than or equal to the hands-off permission time S. The hands-off permission time S is determined according to the type of area requiring attention. The hands-off permission time S is stored in the ECU10. T(s)>S(s) → Allow T(s)≦S(s) → Not allowed

[0027] If the ECU10 does not permit hands-off driving control, it requests the driver to drive with their hands on the steering wheel (hereinafter also referred to as "hands-on"). For example, the ECU10 may send a control signal to the HMI5 and, as a request to the driver, display a notification on the HMI5's display prompting hands-on driving, or output an audio and buzzer from the HMI5's speaker prompting hands-on driving.

[0028] After receiving a request for hands-on driving, the ECU10 determines whether the driver is in hands-on mode or not. Whether the driver is in hands-on mode or not can be determined using, for example, the output from the steering touch sensor, torque sensor, and driver monitoring camera. Based on the result of this determination, the ECU10 continues driving control if the driver is in hands-on mode, and terminates driving control if the driver is not in hands-on mode.

[0029] Next, we will explain the processing of the driver assistance system 1, referring to the flowchart in Figure 2. In the following explanation, we will use the example where the area requiring attention is an intersection and lane keeping control is performed as the driving control.

[0030] If an intersection exists ahead of vehicle V, which is continuing lane keeping control with hands-off operation, the following process is executed. First, the ECU 10 calculates the time T to reach the intersection (step S1). The ECU 10 determines whether the time T is greater than the hands-off permission time S, and based on this, determines whether to permit hands-off lane keeping control (step S2). If the answer in step S2 is YES, hands-off lane keeping control is permitted and the lane keeping control is continued (step S3). After that, the processing for this cycle ends and the process moves to step S1 of the next cycle.

[0031] If the answer in step S2 is NO, lane keeping control in hands-off mode is not permitted, and the ECU 10 requests the driver to drive with hands on (step S4). It is determined whether the driver's state is hands-on or not (step S5). If the answer in step S5 is YES, lane keeping control is continued (step S6). On the other hand, if the answer in step S5 is NO, lane keeping control is terminated (step S7). After steps S6 and S7, the process ends.

[0032] Figure 3(a) is a schematic diagram showing an example of the permitted range of hands-off driving by the driver assistance system in the comparative example. Figure 3(b) is a schematic diagram showing an example of the permitted range of hands-off driving by driver assistance system 1. In the examples in Figures 3(a) and 3(b), there are two intersections I1 and I2 in front of the vehicle V in the direction of travel, and congestion (slow traffic flow) occurs between intersection I1 and intersection I2. The comparative example corresponds to a driver assistance system that does not permit hands-off driving control when the vehicle V is located within a certain distance from intersections I1 and I2 in the direction of travel.

[0033] As shown in Figure 3(a), in the comparative example's driver assistance system, hands-off driving control is permitted until the distance from vehicle V to intersection I1 is a certain distance. Once the distance from vehicle V to intersection I1 falls below a certain distance, hands-off driving control is no longer permitted, and hands-on driving control is required. After vehicle V enters and exits intersection I1, the distance from vehicle V to intersection I2 is a certain distance, and therefore, regardless of the traffic congestion ahead, hands-off driving control is still no longer permitted, and hands-on driving control is required. Then, after vehicle V enters and exits intersection I2, hands-off driving control is permitted again.

[0034] In contrast, as shown in Figure 3(b), in the driving support system 1 of this embodiment, hands-off driving control is permitted until the arrival time T to intersection I1 is less than or equal to the hands-off permitted time S. Once the arrival time T to intersection I1 is less than or equal to the hands-off permitted time S, hands-off driving control is not permitted, and hands-on driving control is required. After vehicle V enters and exits intersection I1, traffic congestion occurs ahead and the traffic flow is slow, so the arrival time T to intersection I1 is greater than the hands-off permitted time S. Therefore, regardless of the distance of vehicle V to intersection I2, hands-off driving control is permitted. Once the arrival time T to intersection I2 is less than or equal to the hands-off permitted time S, hands-off driving control is not permitted, and hands-on driving control is required. Then, after vehicle V enters and exits intersection I2, hands-off driving control is permitted.

[0035] In summary, the driver assistance system 1 can permit hands-off driving control based on the time T it takes for vehicle V to reach a caution area. Therefore, for example, when vehicle V approaches a caution area in a situation with slow traffic flow such as congestion, it is possible to prevent hands-off driving control from being unnecessarily restricted. The system determines whether or not hands-off driving control is permitted by taking into account the distance to the caution area and the traffic flow, thereby reducing inconvenience while ensuring that hands-off driving control is not unnecessarily restricted.

[0036] In the driver assistance system 1, the areas requiring attention are at least one of the following: intersections, construction zones, sections containing accident sites, and sections with a high frequency of accidents. In this case, at least one of the following can be considered as areas requiring attention: intersections, construction zones, sections containing accident sites, and sections with a high frequency of accidents.

[0037] In driver assistance system 1, the permitted hands-off time is determined according to the type of area requiring attention. In this case, the above effect can be achieved by preventing excessive restriction of hands-off driving control depending on the type of area requiring attention.

[0038] The driver assistance system 1 prohibits hands-off driving control if the arrival time T is less than or equal to the hands-off permission time S. In this case, if the arrival time T is less than or equal to the hands-off permission time S and the vehicle is about to reach, for example, a caution area, the system can restrict the hands-off driving control so that it is not performed.

[0039] If the driver assistance system 1 denies driving control when the driver is not holding the steering wheel, it will request the driver to drive with hands on. This allows the system to prompt the driver to drive with hands on when hands-off driving control is not permitted.

[0040] Although embodiments have been described above, the present invention is not limited to the embodiments described above. One embodiment of the present invention can be implemented in various forms, starting with the embodiments described above, with various modifications and improvements based on the knowledge of those skilled in the art.

[0041] In the above embodiment, areas requiring attention were listed as intersections, construction zones, sections including accident sites, and sections with a high frequency of accidents. However, areas requiring attention are not particularly limited and may include other areas requiring attention. In the above embodiment, notifications via display and / or voice through the HMI5 were used to indicate a need for hands-on driving. However, the system is not limited to this, and various types of notifications may be used. For example, seat vibration notifications may be used. [Explanation of Symbols]

[0042] 1...Driver assistance system, 2...Internal sensor, 3...External sensor, 4...Navigation system, 5...HMI, 6...Actuator, 10...ECU, V...Vehicle.

Claims

1. A driver assistance system that can continue to control the driving of a vehicle when the driver of the vehicle is not holding the steering wheel, The time it takes for the vehicle to reach a high-risk area, which is at least one of the following: an intersection, a construction zone, a section containing an accident site, or a section with a high frequency of accidents, is calculated based on the distance to the high-risk area and the traffic flow. A driver assistance system that permits driving control while the driver is not holding the steering wheel if the arrival time is greater than the hands-off permission time, which is determined and stored according to the type of area requiring attention.

2. The driving assistance system according to claim 1, wherein if the arrival time is less than or equal to the hands-off permission time, the driving control when the driver is not holding the steering wheel is not permitted.

3. The driving assistance system according to claim 2, wherein if the driving control is not permitted when the driver is not holding the steering wheel, the system requests the driver to drive while holding the steering wheel.

4. The driving assistance system according to claim 3, which, after requesting the driver to drive while holding the steering wheel, determines that the driver is holding the steering wheel, and continues the driving control.

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