Driving assistance method and driving assistance device

Abstract

The present application provides a kind of driving assistance method and driving assistance device, in the time of setting the time of starting the host vehicle based on the elapsed time from the host vehicle parking to the front vehicle existing in front of the host vehicle, compared with the time set in the case of shorter elapsed time, the time is set later in the case of longer elapsed time, and the host vehicle is started following the front vehicle at the set time.

Description

Technical Field

[0001] This invention relates to driving assistance methods and driving assistance devices. Background Technology

[0002] Previously, an invention that enables a vehicle to automatically follow the vehicle in front was known (Patent Document 1). The invention described in Patent Document 1 detects the number of times a vehicle has entered a start request by the driver when the vehicle is stopped and waiting for a signal, and sets a start permission period based on the number of detected start requests.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: International Publication No. 2017 / 009940 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] According to the invention described in Patent Document 1, during the standby period from when a start-up request is detected until the preset start-up conditions of the vehicle are met, the driver's attention may decrease. Therefore, in cases where the standby period is long, the driver may not be able to respond quickly to the start of the vehicle.

[0008] The present invention was made in view of the above-mentioned problems, and its object is to provide a driving assistance method and driving assistance device that can ensure the time before the driver regains attention when the vehicle starts to follow the vehicle in front.

[0009] Technical solutions for solving technical problems

[0010] In one aspect of the present invention, a driving assistance method and driving assistance device, when setting the time for starting the vehicle based on the elapsed time from when the vehicle stops to when a preceding vehicle in front of the vehicle starts moving, sets the time later when the elapsed time is longer compared to the time set when the elapsed time is shorter, and causes the vehicle to start following the preceding vehicle at the set time.

[0011] The effects of the invention

[0012] According to the present invention, it is possible to ensure the time before the driver regains attention when the vehicle starts to follow the vehicle in front. Attached Figure Description

[0013] Figure 1 This is a block diagram illustrating the structure of a driving assistance device according to one embodiment of the present invention.

[0014] Figure 2This is a flowchart illustrating the processing of a driving assistance device according to one embodiment of the present invention. Detailed Implementation

[0015] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same reference numerals are used for the same parts, and the description is omitted.

[0016] [Structure of driver assistance devices]

[0017] Reference Figure 1 The structure of the driving assistance device 1 will be described below. The driving assistance device 1 is mounted on the vehicle equipped with autonomous driving functions. Autonomous driving functions include ACC (Adaptive Cruise Control), lane keeping assist, automatic lane changing, and automatic parking, but in this embodiment, the driving assistance device 1 is mainly used for ACC. ACC refers to an autonomous driving function that uses a pre-set speed by the user as an upper limit, automatically controls the acceleration and deceleration of the vehicle, and follows the vehicle in front. Distance control is also performed at this time to maintain a distance from the vehicle corresponding to the set speed.

[0018] Follow control also includes the control that enables a vehicle to follow the vehicle in front after it is detected that the vehicle in front has started moving during periods of rest such as waiting at a signal or in traffic congestion.

[0019] like Figure 1 As shown, the driver assistance device 1 includes: a camera 10, a radar 11, a sonar 12, a vehicle speed sensor 13, a GPS receiver 14, a switch 15, a controller 20, a steering actuator 30, an accelerator pedal actuator 31, and a brake actuator 32. In addition, the driver assistance device 1 may also include a navigation device (not shown).

[0020] Multiple cameras 10 are installed at the front, sides, rear, and side mirrors of the vehicle. Each camera 10 has an imaging element such as a CCD (charge-coupled device) or a CMOS (complementary metal oxide semiconductor). The cameras 10 detect objects (pedestrians, bicycles, two-wheeled vehicles, other vehicles, etc.) and surrounding information (road markings, traffic lights, signs, crosswalks, intersections, etc.). The cameras 10 output the captured images to the controller 20.

[0021] Multiple radars 11 are installed at the front, front sides, and rear sides of the vehicle. Each radar 11 emits radio waves towards objects around the vehicle and measures the reflected waves to determine the distance and direction to the objects. The radars 11 then output the measured data to the controller 20.

[0022] Sonar 12 is mounted on the front bumper or front grille. Sonar 12 emits ultrasonic waves and measures the reflected waves to determine the distance and direction of objects near the vehicle (e.g., about 1m to 2m). Sonar 12 outputs the measured data to controller 20.

[0023] The vehicle speed sensor 13 detects the speed of the vehicle and outputs the detected speed to the controller 20.

[0024] GPS receiver 14 detects the vehicle's position information on the ground by receiving radio waves from artificial satellites. The position information detected by GPS receiver 14 includes latitude and longitude. It should be noted that the method for detecting the vehicle's position information is not limited to GPS receiver 14. For example, a method called the range finding method can also be used to estimate the position. The range finding method estimates the vehicle's position by calculating the amount and direction of movement based on the vehicle's rotation angle and angular velocity. The location of GPS receiver 14 is not particularly limited, but as an example, GPS receiver 14 is installed on the vehicle's dashboard. GPS receiver 14 outputs the detected position information to controller 20.

[0025] Multiple switches 15 are provided on the steering wheel. These switches 15 include: a switch for adjusting the set speed controlled by ACC, a switch for setting the inter-vehicle distance when ACC is activated, and a switch for initiating following motion when the vehicle in front starts moving. In this embodiment, the switches 15 are described as physical switches, but are not limited thereto. The switches 15 may also be virtual switches. When the switches 15 are virtual switches, they may also be displayed on a touch panel used in the navigation device.

[0026] The controller 20 is an electronic control unit (ECU) that includes a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), CAN (Controller Area Network) communication circuits, etc.

[0027] A computer program for functioning as a driving assistance device 1 is installed in the controller 20. By executing the computer program, the controller 20 functions as multiple information processing circuits of the driving assistance device 1. It should be noted that this example illustrates the implementation of multiple information processing circuits of the driving assistance device 1 using software; however, dedicated hardware for performing the various information processing operations described below can also be prepared to construct the information processing circuits. Alternatively, multiple information processing circuits can be constructed using a single piece of hardware.

[0028] The controller 20 comprises multiple information processing circuits, including a lane detection unit 21, a forward vehicle detection unit 22 (acquisition unit), a following vehicle unit 23 (driving control unit), a determination condition setting unit 24 (setting unit), and a determination unit 25.

[0029] The lane detection unit 21 uses images acquired by the camera 10 to detect the lane in which the vehicle is traveling. Specifically, the lane detection unit 21 extracts lane markings from the images to detect the lane in which the vehicle is traveling. The lane detection unit 21 may also add the vehicle's position information to detect the lane in which the vehicle is traveling.

[0030] The forward vehicle detection unit 22 (acquisition unit) detects a vehicle in front of the vehicle using images acquired from the camera 10. Furthermore, the forward vehicle detection unit 22 uses data acquired from the radar 11 to detect the distance between the vehicle and the vehicle in front, as well as the relative speed between the two vehicles. In this embodiment, the vehicle in front is defined as a vehicle traveling in the same lane as the vehicle in front. Additionally, the forward vehicle detection unit 22 acquires the time elapsed from when the vehicle in front stops until the vehicle in front starts moving again.

[0031] Based on the detection results from the vehicle speed sensor 13 and the preceding vehicle detection unit 22, the determination unit 25 detects that the vehicle or the preceding vehicle has started moving. In addition, the determination unit 25, based on the location of the vehicle (not shown) and the road type the vehicle is traveling on, obtains the road type the vehicle is traveling on and sets a "set time" according to the road type the vehicle is traveling on.

[0032] Here, the "Set Time" can be set to various values ​​depending on the type of road the vehicle is traveling on. For example, when the vehicle is traveling on ordinary roads, a first specified time can be set as the set time; when the vehicle is traveling on highways or dedicated motor vehicle lanes, a second specified time, which is longer than the first specified time, can be set as the set time. For example, the first specified time could be approximately 3 seconds, and the second specified time could be approximately 30 seconds. In addition, the "Set Time" can also be set based on user instructions.

[0033] Based on the detection results of the preceding vehicle detection unit 22, the determination unit 25 determines whether the preceding vehicle has started moving within a set time after the current vehicle has stopped. In addition, based on the detection results of the preceding vehicle detection unit 22, the determination unit 25 determines whether the "determination conditions" set by the determination condition setting unit 24, which will be described later, have been met.

[0034] In addition, the determination unit 25 can report to the user, via display, sound, or vibration, that the vehicle or the vehicle in front has started moving, through an output device (not shown) such as a display, warning light, speaker, or vibrator.

[0035] The determination condition setting unit 24 (setting unit) sets "determination conditions" for determining whether the vehicle can start based on the elapsed time from when the vehicle stops to when the vehicle in front starts moving. Since it is possible to determine when the vehicle can start at the moment when the determination condition is met, the moment when the determination condition is met can be regarded as equivalent to the moment when the vehicle starts moving. Therefore, the following explanation does not specifically distinguish between the moment when the determination condition is met and the moment when the vehicle starts moving.

[0036] Based on the determination conditions set by the determination condition setting unit 24, the time for starting the vehicle is set later when the elapsed time is longer, compared to the time when the elapsed time is shorter. The determination condition setting unit 24 can set the time for starting the vehicle based on the determination conditions, or it can set the time for starting the vehicle itself.

[0037] Alternatively, the determination condition setting unit 24 can also set "the inter-vehicle distance between the preceding vehicle and the current vehicle is a predetermined distance or more" as a determination condition. Here, the determination condition setting unit 24 sets the predetermined distance based on the elapsed time. For example, the determination condition setting unit 24 can compare the predetermined distance set when the elapsed time is shorter and set a longer predetermined distance when the elapsed time is longer. The longer the elapsed time, the longer the predetermined distance is set by the determination condition setting unit 24.

[0038] Based on these established criteria, after the preceding vehicle starts moving, the starting of this vehicle is restricted until the distance between the preceding and following vehicles gradually increases to reach the specified distance. Therefore, compared to the time when the vehicle starts after a shorter period of time, the time when the vehicle starts after a longer period of time will be set later.

[0039] Furthermore, the determination condition setting unit 24 can also set "the speed of the preceding vehicle is above a predetermined speed" as a determination condition. Here, the determination condition setting unit 24 sets the predetermined speed based on the elapsed time. For example, the determination condition setting unit 24 can compare the predetermined speed set when the elapsed time is shorter, and set a larger predetermined speed when the elapsed time is longer. The longer the elapsed time, the higher the predetermined speed set by the determination condition setting unit 24.

[0040] Based on these established criteria, after the vehicle in front starts moving, the starting speed of this vehicle is restricted until the speed of the vehicle in front gradually increases to above the prescribed speed. Therefore, compared to the time when this vehicle starts after a shorter period of time, the time when this vehicle starts after a longer period of time will be set later.

[0041] The following driving unit 23 (driving control unit) controls the following driving of the vehicle so that it automatically follows the vehicle in front. Specifically, when the user turns on the switch to activate ACC, the following driving unit 23 controls the steering actuator 30, accelerator pedal actuator 31, and brake actuator 32, using a speed preset by the user as the upper limit to make the vehicle follow the vehicle in front. At this time, the following driving unit 23 also performs distance control to maintain the inter-vehicle distance corresponding to the set speed. It should be noted that the user can also specify the inter-vehicle distance.

[0042] If no vehicle is detected ahead when the user turns on the switch to activate ACC, the following driving unit 23 keeps the vehicle traveling at a set speed. Alternatively, if no speed is set, the following driving unit 23 can use the legal speed limit on the road the vehicle is currently traveling as the upper limit, allowing the vehicle to travel automatically.

[0043] The following unit 23 can also set the rate of change of the vehicle's acceleration at start-up based on the elapsed time. More specifically, the following unit 23 can compare the rate of change of the vehicle's acceleration at start-up with a shorter elapsed time, and set a smaller rate of change of the vehicle's acceleration at start-up when the elapsed time is longer. Furthermore, the following unit 23 can set the vehicle's acceleration at start-up such that the longer the elapsed time, the smaller the rate of change of the vehicle's acceleration at start-up. That is, the longer the set time, the more slowly the vehicle controlled by the following unit 23 begins to accelerate.

[0044] The following driving unit 23 can perform the aforementioned following driving control based on the determination result of the determination unit 25, after the vehicle has stopped, after the preceding vehicle has started moving within a set time, and when the determination conditions set by the determination condition setting unit 24 have been met. On the other hand, the following driving unit 23 can also keep the vehicle stationary or in standby mode after the vehicle has stopped, when the preceding vehicle has not started moving within a set time, or when the determination conditions have not been met.

[0045] [Processing flow for driver assistance devices]

[0046] Next, refer to Figure 2 The flowchart illustrates the processing flow of the driving assistance device in this embodiment. Figure 2 The processing of the driving assistance device shown can be repeated at a predetermined cycle.

[0047] In step S101, the determination unit 25 determines whether the vehicle is located on a designated road (e.g., a highway or a motor vehicle-only road).

[0048] If it is determined that the vehicle is not on the designated road (NO in step S101), in step S105, the determination unit 25 sets the first designated time to the set time.

[0049] On the other hand, if it is determined that the vehicle is on a designated road (the case is YES in step S101), in step S103, the determination unit 25 sets the second designated time to the set time.

[0050] In step S107, the determination condition setting unit 24 sets the "determination condition" for determining whether the vehicle can start.

[0051] In step S109, the determination unit 25 determines whether the determination condition set by the determination condition setting unit 24 has been satisfied.

[0052] If the determination condition is not met (NO in step S109), in step S115, the following driving unit 23 keeps the vehicle stationary and in standby mode.

[0053] On the other hand, if the determination condition has been met (YES in step S109), in step S111, the following driving unit 23 sets the acceleration of the vehicle when it starts. Then, in step S113, the following driving unit 23 controls the vehicle to start with the set acceleration.

[0054] [Effects of the Implementation Method]

[0055] As explained in detail above, when the driving assistance method and driving assistance device of this embodiment start the vehicle by following a vehicle in front of it, they obtain the elapsed time from when the vehicle stops to when the vehicle in front starts. When the controller sets the time to start the vehicle based on the elapsed time, compared with the time set when the elapsed time is short, the time is set later when the elapsed time is long, and the vehicle starts at the set time.

[0056] This ensures that the time before the driver regains attention when starting to follow the vehicle in front is sufficient. Furthermore, it allows the vehicle to determine when it can start later, and when the vehicle in front has moved further away, even after a longer delay. As a result, user discomfort is reduced.

[0057] Furthermore, it enables a smooth start-up of this vehicle as the vehicle in front begins to move after the vehicle has stopped. For example, if it is determined that the vehicle can start at a later time even with a long delay, sufficient time can be ensured before the vehicle starts to start, allowing the vehicle's systems (including the engine, navigation, and other vehicle control systems) to begin operation. As a result, the load on the vehicle's systems that may occur during startup can be reduced.

[0058] It should be noted that although it is determined that the vehicle can start earlier if the elapsed time is short, it can be determined that the vehicle's system does not need to be stopped in this situation. Therefore, unnecessary system shutdowns can be avoided, and the load on the vehicle's system can be reduced.

[0059] This system addresses the need for increased driver attention recovery. In situations where the time between a stop and restart is prolonged, the driver's attention may diminish. To mitigate this, because the distance between the vehicle and the vehicle in front increases when the vehicle starts moving, sufficient time is provided for the driver to recover their attention during the start and approach phases. As a result, the driver can begin driving with ease. Furthermore, the driver can ride comfortably while controlling the vehicle to follow the vehicle in front.

[0060] Here, "starting to drive with ease" means that the user has ample time to regain attention, grip the steering wheel, and become fully aware of the driving operation. Similarly, "riding with ease" means that, in conjunction with the vehicle's movement, the user has ample time to achieve the appropriate posture.

[0061] Because it is determined that the vehicle can start earlier in a shorter time, the time from when the vehicle stops to when it starts again is shortened, which can ensure the vehicle's ability to follow the starting of the vehicle in front.

[0062] Furthermore, the driving assistance method and driving assistance device of this embodiment can set a predetermined distance based on the elapsed time. Compared with the predetermined distance set when the elapsed time is short, the predetermined distance is set to be longer when the elapsed time is long, and the vehicle starts when the inter-vehicle distance between the preceding vehicle and the current vehicle becomes more than the predetermined distance.

[0063] Therefore, even over extended periods, a longer distance can be maintained between the vehicle and the vehicle in front when starting. As a result, even if the user's attention may be diminished, sufficient time is ensured for the user to regain attention during the period from starting to approaching the vehicle in front.

[0064] In addition, because the distance between the vehicle and the vehicle in front is shortened when the time is short, the vehicle's ability to follow the vehicle in front when it starts is ensured.

[0065] Furthermore, the driving assistance method and driving assistance device of this embodiment can set a predetermined speed based on the elapsed time. Compared with the predetermined speed set when the elapsed time is short, the predetermined speed is set to be larger when the elapsed time is long, so that the vehicle can start when the speed of the vehicle in front reaches or exceeds the predetermined speed.

[0066] Therefore, over longer periods, the relative speed between the vehicle and the vehicle in front can be increased. As a result, even if the user's attention may be diminished, sufficient time is ensured for the user to regain attention during the vehicle's initial movement and approach to the vehicle in front.

[0067] In addition, because the relative speed between this vehicle and the vehicle in front decreases when the time is short, it is possible to ensure that this vehicle can follow the vehicle in front when it starts moving.

[0068] Furthermore, in the driving assistance method and device of this embodiment, compared to the rate of change of vehicle acceleration during start-up when the time interval is short, the rate of change of vehicle acceleration during start-up can be set to be smaller when the time interval is long. Therefore, when the time interval is long, the vehicle's acceleration during start-up increases smoothly. Thus, even if the user's attention may be reduced due to the longer time between stopping and restarting, sufficient time is ensured for the user to regain attention during the start-up and approach of the vehicle in front. As a result, the user can begin driving with ease.

[0069] Furthermore, the driving assistance method and device of this embodiment determine whether the vehicle is on a designated road. If it is determined that the vehicle is not on a designated road, a first designated time is set as a set time. If it is determined that the vehicle is on a designated road, a second designated time, which is longer than the first designated time, is set as a set time. If the vehicle stops and the vehicle in front starts moving within the set time, the vehicle can be started again. In particular, the designated road can be a highway or a dedicated motor vehicle road. Therefore, on designated roads where pedestrians or bicycles cross infrequently, a longer set time can be used, reducing the number of times the user needs to operate the vehicle.

[0070] On the other hand, on roads where pedestrians or bicycles are more likely to cross, the set time can be set to be shorter, reducing the distance between the vehicle and the vehicle in front. As a result, the likelihood of pedestrians or bicycles crossing between the vehicle and the vehicle in front can be reduced, and factors that hinder the vehicle's ability to follow the vehicle in front can be reduced.

[0071] The functions described in the above embodiments can be implemented by one or more processing circuits. The processing circuits include programmable processors, electronic circuits, etc., as well as devices such as application-specific integrated circuits (ASICs), or main components of circuit structures configured to perform the functions.

[0072] The present invention has been described above with reference to embodiments, but the present invention is not limited to the above description, and those skilled in the art can certainly make various modifications and improvements. The discussions and drawings that constitute a part of this disclosure should not be construed as limiting the present invention. Various alternative embodiments, examples, and application techniques will be apparent to those skilled in the art based on this disclosure.

[0073] This invention naturally includes various embodiments not described herein. Therefore, based on the above description, the technical scope of this invention is determined only by the inventive designations within the appropriate technical scope.

[0074] Explanation of reference numerals in the attached figures

[0075] 1. Driving assistance device; 10. Camera; 11. Radar; 12. Sonar; 13. Vehicle speed sensor; 14. GPS receiver; 15. Switch; 20. Controller; 21. Lane detection unit; 22. Forward vehicle detection unit (acquisition unit); 23. Following driving unit (driving control unit); 24. Judgment condition setting unit (setting unit); 25. Judgment unit; 30. Steering actuator; 31. Accelerator pedal actuator; 32. Brake actuator.

Claims

1. A driving assistance method, comprising controlling a controller that initiates the movement of a vehicle by following a vehicle positioned in front of it, characterized in that, The controller obtains the elapsed time from when the vehicle in front of it stops to when the vehicle in front of it starts moving. When the controller sets the time for the vehicle to start based on the elapsed time, it sets the time later when the elapsed time is longer, compared to the time set when the elapsed time is shorter. The controller causes the vehicle to start at the specified time. Compared to the rate of change of the vehicle's acceleration at start-up when the elapsed time is shorter, the controller sets a smaller rate of change of the vehicle's acceleration at start-up when the elapsed time is longer.

2. The driving assistance method as described in claim 1, characterized in that, The controller sets a predetermined distance based on the elapsed time. Compared to the predetermined distance set when the elapsed time is shorter, the controller sets a longer predetermined distance when the elapsed time is longer. The controller causes the vehicle to start when the inter-vehicle distance between the preceding vehicle and the vehicle itself becomes greater than the specified distance.

3. The driving assistance method as described in claim 1 or 2, characterized in that, The controller sets a predetermined speed based on the elapsed time. Compared to the predetermined speed set when the elapsed time is shorter, the controller sets a larger predetermined speed when the elapsed time is longer. The controller causes the vehicle to start moving when the speed of the preceding vehicle reaches or exceeds the predetermined speed.

4. A driving assistance device for starting the vehicle by following a vehicle already in front of it, characterized in that it comprises: The acquisition unit acquires the elapsed time from when the vehicle in front of it stops to when the vehicle in front of it starts moving. The setting unit, when setting the time for starting the vehicle based on the elapsed time, compares the time set when the elapsed time is shorter with the time set when the elapsed time is longer, and sets the time later. The driving control unit, which starts the vehicle at the stated time. Compared to the rate of change of the vehicle's acceleration at start-up when the elapsed time is shorter, the driving control unit sets a smaller rate of change of the vehicle's acceleration at start-up when the elapsed time is longer.

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