Driving assistance system

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 assistance system. [Background technology]

[0002] As a technology related to driving assistance systems, for example, Patent Document 1 discloses a technology that enables the vehicle to drive automatically using autonomous driving control when congestion around the vehicle is detected within an area where automatic driving is possible, without the driver having to monitor the surroundings or hold the steering wheel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-176869 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in a driving assistance system that can continue driving control such as lane keeping control while the driver of the vehicle is not holding the steering wheel (hereinafter also referred to as "hands-off"), when the vehicle is located within a certain distance from a caution area such as an intersection, there may be cases where hands-off driving control is not permitted, for example, to ensure safety. In such a driving assistance system, when the vehicle approaches a caution area, for example, in a situation where traffic flow is slow, the driving control may be restricted even though hands-off driving control can still be continued for a sufficient period of time.

[0005] Therefore, an object of one aspect of the present invention is to provide a driving assistance system that can prevent unnecessary restrictions on driving control when the driver is not holding the steering wheel. [Means for solving the problem]

[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 vehicle's driving even when the driver of the vehicle is not holding the steering wheel. The system calculates the arrival time of the vehicle to reach a caution area, and if the arrival time is longer than a set hands-off allowance time, the system allows the driver to control the vehicle without holding the steering wheel.

[0007] This driving assistance system can allow hands-off driving control based on the estimated time it takes for the vehicle to reach a caution area. Therefore, for example, when a vehicle approaches a caution area in slow traffic conditions, it is possible to prevent hands-off driving control from being restricted more than necessary.

[0008] (2) In the driving assistance system described in (1) above, the caution area may be at least one of an intersection, a construction section, a section including an accident site, and a section where accidents frequently occur. In this case, at least one of an intersection, a construction section, a section including an accident site, and a section where accidents frequently occur can be considered as the caution area.

[0009] (3) In the driving assistance system described in (1) or (2) above, the hands-off permission time may be determined according to the type of caution area. In this case, the above-mentioned effect of preventing unnecessary restrictions on hands-off driving control according to the type of caution area can be achieved.

[0010] (4) The driving assistance system described in any one of (1) to (3) above may prohibit driving control in a state where the driver does not hold the steering wheel when the arrival time is equal to or shorter than the hands-off permission time. In this case, when the arrival time is equal to or shorter than the hands-off permission time and, for example, a caution area is about to be reached, the driving control can be restricted so that hands-off driving control is not performed.

[0011] (5) The driving assistance system described in (4) above may request the driver to drive with the steering wheel held when driving control without the driver holding the steering wheel is not permitted. This allows the driver to be encouraged to drive with their 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 driving assistance system that can prevent unnecessary restrictions on driving control when the driver is not holding the steering wheel. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a block diagram showing the configuration of a driving assistance system according to an embodiment. [Figure 2] FIG. 2 is a flowchart showing the processing of the driving assistance system of FIG. [Figure 3] Fig. 3(a) is a schematic diagram showing an example of a hands-off permitted range by a driving assistance system according to a comparative example. Fig. 3(b) is a schematic diagram showing an example of a hands-off permitted range by the driving assistance system of Fig. 1. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or corresponding elements are designated by the same reference numerals, and redundant description will be omitted.

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

[0016] The driving assistance system 1 is a system that can continue to control the driving of the vehicle V when the driver of the 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) that automatically steers the vehicle V so that the vehicle V does not deviate from the driving lane in which the vehicle V is traveling. The driving control is not particularly limited, and may be driving control related to other driving assistance. The driving assistance system 1 includes an ECU (Electronic Control Unit) 10.

[0017] The ECU 10 is an electronic control unit having a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc. The ECU 10 realizes various functions by, for example, loading a program stored in the ROM into the RAM and executing the program loaded into the RAM by the CPU. Some of the functions of the ECU 10 may be executed by a server capable of communicating with the vehicle V. The ECU 10 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 ECU 10.

[0018] The internal sensor 2 is a detection device that detects the traveling state of the vehicle V. The 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 the vehicle V. As the vehicle speed sensor, for example, a wheel speed sensor that detects the rotational speed of the wheels is used. 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 the vehicle V. The acceleration sensor transmits, for example, acceleration information of the vehicle V to the ECU 10. The yaw rate sensor is a detector that detects the yaw rate (rotational angular velocity) around the vertical axis of the center of gravity of the vehicle V. As the yaw rate sensor, for example, a gyro sensor can be used. The yaw rate sensor transmits the detected yaw rate information of the 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, behind the windshield of the vehicle V and captures images in front of the vehicle V. The camera may also be provided on the back and sides of the vehicle V. The camera transmits image information of the surroundings of 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 detects obstacles in the surroundings of the vehicle V using radio waves (e.g., millimeter waves) or light. The radar sensor includes, for example, millimeter wave radar or lidar. The radar sensor transmits 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 predetermined destination. The navigation system 4 recognizes the road and lane on which the vehicle V is traveling 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 uses the HMI 5 to guide the driver along the target route.

[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 that can be seen by the driver. The HMI 5 outputs images on the display and sounds from the speaker in response to control signals from the ECU 10. The HMI 5 may also include a HUD (Head Up Display).

[0022] The actuators 6 are devices used to control the vehicle V. The actuators 6 include at least a drive actuator, a brake actuator, and a steering actuator. The drive actuator controls the engine and / or motor as a power source in response to a control signal from the ECU 10, thereby controlling the driving force of the vehicle V. The brake actuator controls the brake system in response to a control signal from the ECU 10, thereby controlling the braking force applied to the wheels of the vehicle V. The steering actuator controls the drive of an assist motor, which controls the steering torque of the electric power steering system, in response to a control signal from the ECU 10. In this way, the steering actuator controls the steering torque of the vehicle V.

[0023] The ECU 10 executes driving control of the vehicle V. For example, when lane keeping control is performed as driving control, the ECU 10 executes steering control to drive the vehicle V so as to keep the vehicle V in the lane, based on the detection results of the internal sensor 2 and the external sensor 3.

[0024] The ECU 10 of this embodiment calculates the arrival time T for the vehicle V to reach the caution area. The caution area is an area that requires caution. The caution area is an area with low safety. The caution area is at least one of an intersection, a construction section, a section including an accident site, and a section where accidents frequently occur. For example, the intersection, the construction section, the section including an accident site, and the section where accidents frequently occur may be set in advance based on the map database of the navigation system 4 and stored in the ECU 10.

[0025] Specifically, the ECU 10 calculates the travel distance X to the caution area based on the map database of the navigation system 4 and the detection results of the external sensor 3. The ECU 10 calculates the traffic flow Y based on the detection results of the internal sensor 2 and traffic-related information (for example, traffic-related information that can be acquired via VICS (Vehicle Information and Communication System) (registered trademark)). From the calculated travel distance X and traffic flow Y, the ECU 10 calculates the travel time T using the following equation. T(s)=X(m) / Y(m / s)

[0026] As shown below, the ECU 10 permits driving control in a hands-off state when the arrival time T is longer than the set hands-off allowable time S, and does not permit driving control in a hands-off state when the arrival time T is equal to or shorter than the hands-off allowable time S. The hands-off allowable time S is determined according to the type of caution area. The hands-off allowable time S is stored in the ECU 10. T(s)>S(s) → Allow T(s)≦S(s) → Not allowed

[0027] When the ECU 10 disallows hands-off driving control, it requests the driver to drive while holding the steering wheel (hereinafter also referred to as "hands-on"). As an example, the ECU 10 may send a control signal to the HMI 5, and as the request to the driver, the ECU 10 may display a notification on the display of the HMI 5 urging the driver to drive with their hands on, or may output a voice and a buzzer urging the driver to drive with their hands on from the speaker of the HMI 5.

[0028] After receiving a request for hands-on driving, the ECU 10 determines whether the driver's state is hands-on. Whether the driver's state is hands-on can be determined, for example, by using outputs from a touch sensor of the steering wheel, a torque sensor, a driver monitoring camera, etc. If the result of this determination indicates that the driver's state is hands-on, the ECU 10 continues driving control, and if the driver's state is not hands-on, the ECU 10 ends driving control.

[0029] Next, the processing of the driving assistance system 1 will be described with reference to the flowchart in Fig. 2. In the following, an example will be described in which the caution area is an intersection and lane keeping control is performed as driving control.

[0030] When an intersection is present ahead of vehicle V while continuing hands-off lane keeping control, the following process is executed. First, ECU 10 calculates arrival time T to the intersection (step S1). ECU 10 determines whether arrival time T is longer than hands-off permitted time S, and based on this, determines whether hands-off lane keeping control is permitted (step S2). If the answer is YES in step S2, hands-off lane keeping control is permitted and lane keeping control is continued (step S3). Thereafter, the process for this cycle ends, and the process proceeds to step S1 in the next cycle.

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

[0032] Fig. 3(a) is a schematic diagram showing an example of a hands-off permitted range by a driving assistance system according to a comparative example. Fig. 3(b) is a schematic diagram showing an example of a hands-off permitted range by driving assistance system 1. In the examples of Figs. 3(a) and 3(b), two intersections I1 and I2 are located ahead of vehicle V in the traveling direction, and a traffic jam (a situation where traffic flow is slow) occurs between intersections I1 and I2. The comparative example corresponds to a driving assistance system that does not permit hands-off driving control when vehicle V is located within a certain distance from intersections I1 and I2 ahead of vehicle V in the traveling direction.

[0033] As shown in FIG. 3(a), in the driving assistance system according to the comparative example, hands-off driving control is permitted until the distance to intersection I1 of vehicle V becomes a certain distance. Once the distance to intersection I1 of vehicle V becomes equal to or less than the certain distance, hands-off driving control is not permitted and hands-on driving control is required. After vehicle V enters and exits intersection I1, the distance to intersection I2 of vehicle V becomes a certain distance, so hands-off driving control continues to be not permitted and hands-on driving control is required regardless of the traffic congestion occurring ahead. Then, after vehicle V enters and exits intersection I2, hands-off driving control is permitted.

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

[0035] As described above, the driving assistance system 1 can permit hands-off driving control based on the arrival time T of the vehicle V to reach the caution area. Therefore, when the vehicle V approaches the caution area in a situation where traffic flow is slow, such as when a traffic jam occurs, it is possible to prevent hands-off driving control from being restricted more than necessary. The determination of whether hands-off driving control is possible is made taking into account the distance to the caution area and the traffic flow, thereby reducing the hassle and preventing hands-off driving control from being restricted more than necessary.

[0036] In the driving assistance system 1, the caution area is at least one of an intersection, a construction section, a section including an accident site, and a section where accidents frequently occur. In this case, at least one of an intersection, a construction section, a section including an accident site, and a section where accidents frequently occur can be considered as the caution area.

[0037] In the driving assistance system 1, the hands-off permission time is determined according to the type of caution area. In this case, the above-mentioned effect of preventing unnecessary restrictions on hands-off driving control can be achieved depending on the type of caution area.

[0038] The driving assistance system 1 does not permit hands-off driving control when the arrival time T is equal to or less than the hands-off permitted time S. In this case, when the arrival time T is equal to or less than the hands-off permitted time S and, for example, a caution area is soon to be reached, the driving control can be restricted so that hands-off driving control is not performed.

[0039] When driving control is not permitted when the driver is not holding the steering wheel, the driving assistance system 1 requests the driver to drive with their hands on. This makes it possible to encourage the driver to drive with their hands on when hands-off driving control is not permitted.

[0040] Although the embodiments have been described above, one aspect of the present invention is not limited to the above-described embodiments. One aspect of the present invention can be embodied in various forms, including the above-described embodiments, with various modifications and improvements made based on the knowledge of those skilled in the art.

[0041] In the above embodiment, intersections, construction zones, sections including accident sites, and sections where accidents frequently occur are listed as areas requiring attention, but the areas requiring attention are not particularly limited and may be other areas requiring attention. In the above embodiment, display and / or audio notification via the HMI 5 is used as a request for hands-on driving, but this is not limited thereto and various other notifications may be used. For example, notification by seat vibration may be used. [Explanation of symbols]

[0042] 1...driving assistance system, 2...internal sensor, 3...external sensor, 4...navigation system, 5...HMI, 6...actuator, 10...ECU, V...vehicle.

Claims

1. A driving assistance system capable of continuing to control the driving of a vehicle when a driver of the vehicle is not holding the steering wheel, Calculate the time it takes for the vehicle to reach the caution area, A driving assistance system that permits the driving control in a state where the driver is not holding the steering wheel when the arrival time is longer than a set hands-off permission time.

2. The driving assistance system according to claim 1 , wherein the caution area is at least one of an intersection, a construction zone, a zone including an accident site, and a zone where accidents frequently occur.

3. The driving assistance system according to claim 1 , wherein the hands-off permission time is determined depending on the type of the caution area.

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

5. 5. The driving assistance system according to claim 4, wherein when the driving control is not permitted in a state where the driver is not holding the steering wheel, the system requests the driver to drive while holding the steering wheel.

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