Driving assistance method, driving assistance device, and driving assistance program

Abstract

To perform flexible deceleration control according to a travel state of a following vehicle.SOLUTION: In a method of supporting travel of a vehicle, information on a travel environment of the vehicle is acquired. In the method, when there is a deceleration request for the vehicle based on the information on the travel environment, the target deceleration of the vehicle is set on the basis of the information. In the method, travel support control of the vehicle is executed on the basis of the target deceleration. In a case where the information on the travel environment includes information on a following vehicle of the vehicle, when the following vehicle is decelerating, the target deceleration is set to the first target deceleration. On the other hand, in a case where the information on the travel environment includes the information on the following vehicle of the vehicle, when the following vehicle is not decelerating, the target deceleration is set to the second target deceleration which is smaller in deceleration than the first target deceleration.SELECTED DRAWING: Figure 5

Description

Technical Field

[0004] , , , ,

[0005] , , ,

[0003] , ,

[0001] The present disclosure relates to a method, an apparatus, and a program for assisting the running of a vehicle.

Background Art

[0002] Japanese Unexamined Patent Application Publication No. 2010-52547 discloses an apparatus that performs a running speed control for automatically controlling the running speed of a vehicle. When the target speed in the running speed control is changed, this conventional apparatus sets a target acceleration of the vehicle according to this target speed to accelerate the vehicle, or sets a target deceleration of the vehicle according to this target speed to decelerate the vehicle. The conventional apparatus also changes the target acceleration (or target deceleration) of the vehicle to a value larger than the normal target acceleration (or a value smaller than the normal target deceleration) when the approach of a following vehicle is recognized when the target speed is changed.

Prior Art Document

[0006] One of the purposes of this disclosure is to provide a technology for performing flexible deceleration control in accordance with the driving conditions of a following vehicle. [Means for solving the problem]

[0007] The first aspect of this disclosure is a method for assisting the driving of a vehicle, and has the following features: The aforementioned method, The steps include: acquiring information regarding the driving environment of the vehicle; If there is a request for deceleration of the vehicle based on the information regarding the driving environment, the step of setting a target deceleration speed for the vehicle based on that information, The steps include: performing driving support control of the vehicle based on the target deceleration; Includes. In the step of setting the target deceleration, When the information regarding the driving environment includes information about a vehicle following the vehicle, if the following vehicle is decelerating, the target deceleration is set to a first target deceleration; if the following vehicle is not decelerating, the target deceleration is set to a second target deceleration which has a smaller deceleration rate than the first target deceleration.

[0008] The second aspect of this disclosure is a device that assists in the driving of a vehicle, and has the following features: The aforementioned device includes a processor. The aforementioned processor, A process for acquiring information regarding the driving environment of the aforementioned vehicle, A process to determine whether or not there is a request to decelerate the vehicle based on the information regarding the driving environment, If it is determined that there is a request for deceleration, the process of setting a target deceleration for the vehicle based on the information regarding the driving environment is performed. A process to perform driving support control of the vehicle based on the target deceleration, It is configured to perform the following actions. In the process of setting the target deceleration, the processor If the information regarding the driving environment includes information about a vehicle following the vehicle, and the following vehicle is decelerating, the target deceleration is set to the first target deceleration. If the information regarding the driving environment includes information about a vehicle following the vehicle, and the following vehicle is not decelerating, the target deceleration is set to a second target deceleration, which is less deceleration than the first target deceleration.

[0009] The third aspect of this disclosure is a program that assists in the operation of a vehicle, and has the following characteristics: The aforementioned program, A process for acquiring information regarding the driving environment of the aforementioned vehicle, A process to determine whether or not there is a request to decelerate the vehicle based on the information regarding the driving environment, If it is determined that there is a request for deceleration, the process of setting a target deceleration for the vehicle based on the information regarding the driving environment is performed. A process to perform driving support control of the vehicle based on the target deceleration, Have the computer do it. In the process of setting the target deceleration, When the information regarding the driving environment includes information about a vehicle following the vehicle, and the following vehicle is decelerating, the target deceleration is set to a first target deceleration. If the information regarding the driving environment includes information about a vehicle following the vehicle, and the following vehicle is not decelerating, the target deceleration is set to a second target deceleration which is less deceleration than the first target deceleration.

Advantages of the Invention

[0010] According to the present disclosure, when information on a following vehicle is included in information regarding the driving environment, the target deceleration is set to the first target deceleration when the following vehicle is decelerating. On the other hand, when information on a following vehicle is included in information regarding the driving environment and the following vehicle is not decelerating, the target deceleration is set to the second target deceleration. Here, the second target deceleration has a smaller deceleration than the first target deceleration. Therefore, by performing deceleration control based on the second target deceleration, it is possible to suppress the distance to the following vehicle from narrowing in a short time. Also, by appropriately setting the first target deceleration, it is possible to suppress the distance to the following vehicle from narrowing in a short time even when deceleration control based on this first target deceleration is executed. Thus, according to the present disclosure, it is possible to perform flexible deceleration control according to the driving state of the following vehicle.

Brief Description of the Drawings

[0011] [Figure 1] It is a diagram for explaining the outline of the embodiment. [Figure 2] It is a diagram for explaining the outline of the embodiment. [Figure 3] It is a diagram for explaining the outline of the embodiment. [Figure 4] It is a block diagram for explaining a configuration example of a driving support device according to an embodiment. [Figure 5] It is a flowchart showing the flow of processing particularly related to an embodiment.

Modes for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present disclosure will be described while referring to the drawings. In each figure, the same or corresponding parts are denoted by the same reference numerals, and the description thereof is simplified or omitted.

[0013] 1. Outline of the Embodiment Figures 1-3 are diagrams illustrating the outline of the embodiment. Figure 1 also illustrates an example of a situation assumed by the embodiment. Figures 2 and 3 also illustrate the features of the embodiment. Figure 1 shows vehicles M1 and M2. Vehicle M2 is a vehicle traveling in the same lane as vehicle M1, following behind vehicle M1 in the same direction (i.e., a trailing vehicle). There are no other vehicles between vehicle M1 and vehicle M2.

[0014] In the example shown in Figure 1, vehicles M1 and M2 are approaching the boundary BD between sections LT1 and LT2, where different legal speed limits are set. The legal speed VL1 in section LT1 is faster than the legal speed VL2 in section LT2. Therefore, for example, if vehicle M1 is traveling at a speed faster than the legal speed VL2 in section LT1, vehicle M1 will decelerate when entering section LT2. Examples of "when entering section LT2" include the time when vehicle M1 reaches the boundary BD, or the time before vehicle M1 reaches the boundary BD. The time before vehicle M1 reaches the boundary BD is, for example, the time when the distance from vehicle M1 to boundary BD becomes less than or equal to a predetermined distance. The predetermined distance may be a fixed value, or it may be set variably according to the travel speed of vehicle M1 (hereinafter also referred to as "speed VM1").

[0015] Vehicle M1 is equipped with a driving support device 10 according to this embodiment. The driving support device 10 performs control to assist the driving of vehicle M1 (hereinafter also referred to as "driving support control"). Examples of this driving support control include lane keeping control, preceding vehicle following control, and collision avoidance control. Lane keeping control is a control that makes vehicle M1 drive along the lane in which it is traveling. Preceding vehicle following control is a control that makes vehicle M1 follow the driving of a vehicle traveling in front of vehicle M1 in the same direction as vehicle M1 (i.e., a preceding vehicle). Collision avoidance control is a control that prevents vehicle M1 from colliding with an obstacle in front of vehicle M1. Driving support control may be performed for the purpose of assisting manual driving by the driver of vehicle M1, or it may be performed as part of the automated driving of vehicle M1.

[0016] Figures 2 and 3 show two examples of the behavior of vehicles M1 and M2 near the boundary BD. For the sake of explanation, the first example of behavior will be referred to as Example CASE_C1, and the second example of behavior will be referred to as Example CASE_C2. Examples CASE_C1 and CASE_C2 are also two examples of behavior that can be assumed at time t=Ta. Therefore, if vehicles M1 and M2 behave as shown in one example, they will not behave as shown in the other example.

[0017] In examples CASE_C1 and CASE_C2, the driving support device 10 performs driving support control to ensure compliance with the legal speed limit. In this driving support control, the vehicle M1's running gear (drive and brake systems) is controlled so that the vehicle M1 travels at a speed of VL1 or less in section LT1 and at a speed of VL2 or less in section LT2. In examples CASE_C1 and CASE_C2, consider the case where the speed VM1 at time t=Ta is faster than the legal speed VL2. In this case, in examples CASE_C1 and CASE_C2, driving support control is performed when entering section LT2. More precisely, control to support the deceleration of vehicle M1 (hereinafter also referred to as "deceleration support control") is started at a time before time t=Ta and before vehicle 1 reaches boundary BD.

[0018] In this example, CASE_C2 shows that vehicle M2 is decelerating at time t=Ta, just like vehicle M1, whereas in CASE_C1, vehicle M2 is not decelerating. Therefore, in CASE_C1, when deceleration support control is performed for vehicle M1, it is expected that the distance between vehicle M1 and vehicle M2 will decrease rapidly. In this case, depending on the deceleration of vehicle M1 (hereinafter also referred to as "deceleration DSM1") and the travel speed of vehicle M2, the driver (or occupant) of vehicle M1 may feel uneasy about the sudden approach of vehicle M2.

[0019] Let's consider the case in example CASE_C1 where vehicle M1 briefly decelerates, activating its brake lights in anticipation of vehicle M2 beginning to decelerate. In this case, while it is possible to avoid a sudden approach by vehicle M2, vehicle M1 itself will not decelerate sufficiently. Therefore, it will take a long time to reduce speed VM1 to below the legal speed limit VL2. This makes it difficult to comply with the legal speed limit when entering section LT2, or immediately after entering section LT2.

[0020] Furthermore, as already mentioned, in example CASE_C2, vehicle M2 is decelerating. Therefore, if the deceleration DSM1 in example CASE_C2 is not within an acceptable range for the driver (or occupant) of vehicle M2, the driver (or occupant) of vehicle M2 may feel uncomfortable with the deceleration of vehicle M1. Thus, when vehicle M2 is present, it is desirable to provide deceleration support control for vehicle M1 according to the driving state of vehicle M2 in order to ensure safe and smooth traffic around vehicle M1.

[0021] Therefore, in this embodiment, the target deceleration of vehicle M1 in the deceleration support control of vehicle M1 (hereinafter also referred to as "deceleration TDSM1") is set variably based on rear recognition information from vehicle M1. Specifically, if the rear recognition information includes recognition information of vehicle M2, it is determined whether or not vehicle M2 is decelerating based on this recognition information of vehicle M2. If it is determined that vehicle M2 is decelerating, the deceleration TDSM1 is set to deceleration DSM1_B (e.g., CASE_C2). An example of deceleration DSM1_B is a deceleration that can reduce the speed VM1 to the legal speed VL2 or less without delay when entering section LT2, or after entering section LT2.

[0022] On the other hand, if it is determined that vehicle M2 is not decelerating, the deceleration TDSM1 is set to deceleration DSM1_A (e.g., CASE_C1). An example of deceleration DSM1_A is a deceleration with a smaller deceleration ratio than deceleration DSM1_B. Here, a smaller deceleration ratio means a gradual deceleration. Specifically, when deceleration DSM1_B is -0.15G, deceleration DSM1_A is -0.05G. Note that deceleration DSM1_A is an example of the "first target deceleration" in this disclosure, and deceleration DSM1_B is an example of the "second target deceleration" in this disclosure.

[0023] In example CASE_C2, if the recognition information for vehicle M2 includes information on the relative speed of vehicle M2 to vehicle M1, the deceleration of vehicle M2 (hereinafter also referred to as "deceleration DSM2") may be calculated based on this relative speed information. In this case, deceleration TDSM1 may be set to the same deceleration as deceleration DSM2. Alternatively, deceleration TDSM1 may be set to a deceleration with a greater deceleration rate than deceleration DSM2. Here, a greater deceleration rate means a sudden deceleration. Specifically, when deceleration DSM2 is -0.15G, deceleration DSM1_B is -0.20G.

[0024] Thus, according to this embodiment, when deceleration support control is performed for vehicle M1, it becomes possible to perform flexible deceleration according to the driving state of vehicle M2. Examples CASE_C1 and CASE_C2 shown in Figure 3 are two types of behavior examples assumed at time t=Tb, which is later than the time t=Ta described in Figure 2. In these examples, the deceleration of vehicle M1 is completed in both cases. In these examples, the distances DV_C1 and DV_C2 between vehicle M1 and vehicle M2 are not extremely narrow. Therefore, according to this embodiment, it is possible to ensure safe and smooth traffic around vehicle M1 in situations where deceleration of vehicle M1 is required.

[0025] 2. Driving support system 2-1. Example Configuration Figure 4 is a block diagram illustrating an example configuration of the driving support device 10 according to the embodiment. As shown in Figure 4, the driving support device 10 includes an external sensor 11, an internal sensor 12, a GNSS (Global Navigation Satellite System) receiver 13, and a map database 14. The driving support device 10 also includes an HMI (Human Machine Interface) unit 15, various actuators 16, and a control device 17.

[0026] The external sensor 11 is a device that detects the conditions around the vehicle M1. Examples of the external sensor 11 include a radar sensor and a camera. The radar sensor uses radio waves (e.g., millimeter waves) or light to detect targets around the vehicle M1. Targets include static and dynamic targets. Examples of static targets include guardrails and buildings. Dynamic targets include pedestrians, bicycles, motorcycles, and vehicles other than vehicle M1. The camera captures images of the conditions outside the vehicle M1. The camera captures images of at least the area in front of the vehicle M1. The camera may also include cameras for capturing images of the area behind and to the sides of the vehicle M1.

[0027] The internal sensor 12 is a device that detects the driving state of the vehicle M1. Examples of internal sensors 12 include a vehicle speed sensor, an acceleration sensor, and a yaw rate sensor. The vehicle speed sensor detects the driving speed of the vehicle M1 (i.e., speed VM1). The acceleration sensor detects the acceleration (or deceleration) of the vehicle M1. The yaw rate sensor detects the yaw rate of the vehicle M1 around the vertical axis of its center of gravity.

[0028] The GNSS receiver 13 is a device that receives signals from three or more artificial satellites. The GNSS receiver 13 is also a device that acquires information about the position of the vehicle M1. Based on the received signals, the GNSS receiver 13 calculates the position and attitude (azimuth) of the vehicle M1.

[0029] The map database 14 is a database that stores map information. Examples of map information include road location information, road shape information (e.g., type of curve, straight), and location information of intersections and structures. The map information also includes traffic regulation information such as legal speed limits. The map database 14 is formed in an in-vehicle storage device (e.g., hard disk, flash memory). The map database 14 may also be formed in a computer of an external device (e.g., an external server) that can communicate with the vehicle M1.

[0030] The surrounding environment information acquired by the external sensor 11, the driving status information acquired by the internal sensor 12, the position and attitude information acquired by the GNSS receiver 13, and the map information are included in the "information regarding the driving environment" of the vehicle M1.

[0031] The HMI unit 15 is a user interface for providing information to and receiving information from the driver of vehicle M1. The HMI unit 15 includes, for example, an input device, a display device, a speaker, and a microphone. Examples of input devices include a touch panel, a keyboard, switches, and buttons. The information provided to the driver includes information about the driving environment of vehicle M1 and warning information for the driver. Information is provided to the driver using the display device and speaker (or warning device). Information is received from the driver using the input device and microphone.

[0032] The various actuators 16 are actuators provided in the vehicle M1's running gear (drive, brake, and steering gear). Examples of the various actuators 16 include drive actuators, brake actuators, and steering actuators. The drive actuator drives the vehicle M1. The brake actuator applies braking force to the vehicle M1. The steering actuator steers the tires of the vehicle M1.

[0033] The control device 17 is comprised of a microcomputer having at least one processor 17a and at least one memory 17b. At least one program is stored in the memory 17b. The at least one program includes a driving support program according to the embodiment. Various types of information, including information about the driving environment of the vehicle M1, are also stored in the memory 17b. Various functions of the control device 17 are realized when the program stored in the memory 17b is read and executed by the processor 17a. These various functions include a function to perform driving support control of the vehicle M1 using various actuators 16.

[0034] 2-2. Processing Example Figure 5 is a flowchart showing the processing flow particularly relevant to this embodiment, performed by the control device 17 (processor 17a). The processing routine shown in Figure 5 is executed repeatedly at a predetermined control cycle.

[0035] In the processing routine shown in Figure 5, it is first determined whether or not there is a deceleration request for vehicle M1 (step S10). In step S10, for example, information about the driving environment of vehicle M1 is obtained, and based on this information, it is determined whether or not there is a deceleration request. Step S10 is repeatedly executed until a positive determination result is obtained.

[0036] In an example related to the embodiment, location information of vehicle M1, map information, and traffic regulation information are acquired, and based on this information, the legal speed limit information for the lane in which vehicle M1 is traveling is identified. If navigation information including destination information for vehicle M1 is available, the legal speed limit information for the lane in which vehicle M1 is scheduled to travel is identified based on this navigation information. Then, based on the identified legal speed limit information and the vehicle M1's current speed information, it is determined whether or not the legal speed limit is being observed. If the speed VM1 exceeds the legal speed limit, it is determined that there is a request for vehicle M1 to slow down. Note that the traffic regulation information may be acquired from the map database 14 or from traffic sign recognition information by the camera.

[0037] If the result of step S10 is positive, it is determined whether or not a following vehicle is within threshold THd1 (step S11). Threshold THd1 is, for example, the distance at which vehicle M1 and the following vehicle are considered to be in close proximity. Threshold THd1 may be a fixed value, may be set variably according to speed VM1, or may be set variably according to the relative speed RV of the following vehicle with respect to vehicle M1.

[0038] In step S11, for example, information regarding the driving environment of vehicle M1 is acquired, and it is determined whether or not this information includes recognition information for a following vehicle. If this determination is positive, it is determined whether or not the distance from vehicle M1 to the following vehicle is less than or equal to the threshold THd1, based on the following vehicle distance information. Note that the following vehicle distance information is either included in the following vehicle recognition information, or calculated separately by processor 17a based on this recognition information.

[0039] If the result of step S11 is positive, it is determined that vehicle M1 and the following vehicle are in close proximity. Therefore, in this case, the deceleration TDSM1 is set to zero (step S12). In the process of step S12, in addition to setting the deceleration TDSM1, the alarm device of the HMI unit 15 may be activated to notify the driver of vehicle M1 that vehicle M1 and the following vehicle are in close proximity.

[0040] If the result of step S11 is negative, it is determined whether or not there is a following vehicle within the threshold THd2 (step S13). The threshold THd2 is the distance at which the distance to the following vehicle is predicted to become extremely short when vehicle M1 performs a short deceleration that causes the brake lights to illuminate (threshold THd1 < threshold THd2). The threshold THd2 may be a fixed value or may be set to be variable according to the speed VM1.

[0041] If the result of step S13 is positive, it is determined whether the relative speed RV is greater than or equal to the speed THv (step S14). Speed ​​THv is, for example, the speed at which the distance to the following vehicle is expected to decrease in a short time when vehicle M1 is decelerated by a predetermined deceleration TDSM1. The relative speed RV information is included in the recognition information of the following vehicle, or is calculated separately by the processor 17a based on this recognition information. Note that the processing in step S14 is not necessarily required, and if the result of step S13 is negative, the processing in step S14 may be skipped and the processing in step S15 may be performed.

[0042] If the result of step S14 is positive, it is determined whether or not the following vehicle is decelerating (step S15). Whether or not the following vehicle is decelerating is determined, for example, based on information about the relative speed RV.

[0043] If the result of the determination in step S15 is negative, the deceleration TDSM1 is set to deceleration DSM1_B (step S16). On the other hand, if the result of the determination in step S15 is positive, the deceleration TDSM1 is set to deceleration DSM1_A (0>DSM1_B>DSM1_A) (step S17). The process in step S17 is also performed if the result of the determination in step S13 or S14 is negative. In the process in step S17, the deceleration TDSM1 may be set to deceleration DSM2. The deceleration DSM2 is included in the recognition information of the following vehicle, or is calculated separately by the processor 17a based on this recognition information.

[0044] Following the processing in step S12, S16, or S17, deceleration support control is performed (step S18). Deceleration support control is performed by generating command values ​​for the vehicle M1's running gear (drive and brake systems) based on the deceleration TDSM1 set in the processing in step S12, S16, or S17, and transmitting these values ​​to the running gear.

[0045] Following the processing in step S18, it is determined whether the speed VM1 has reached the target vehicle speed (step S19). In the example relevant to this embodiment, the target vehicle speed is the legal speed limit of the lane in which vehicle M1 is traveling, or the legal speed limit of the lane in which vehicle M1 is scheduled to travel. If the result of the determination in step S19 is negative, the process returns to step S11. If the result of the determination in step S19 is positive, the processing routine is terminated. [Explanation of Symbols]

[0046] 10 Driving support system 11 External sensors 12 Internal sensors 13 GNSS receiver 14 Map database 15 HMI unit 16 Various actuators 17 Control unit 17a Processor 17b Memory M1, M2 Vehicle LT1, LT2 Section BD Boundary DSM1_A, DSM1_B Deceleration

Claims

1. A method for assisting the driving of a vehicle, which is performed by a computer, The steps include obtaining information about the vehicle's driving environment, including the vehicle's speed and the legal speed limit of the lane in which the vehicle is currently traveling or is scheduled to travel; If the aforementioned driving speed exceeds the aforementioned legal speed limit, the step of determining that there is a request for deceleration for the vehicle and setting a target deceleration speed for the vehicle based on information regarding the vehicle's driving environment, The steps include: performing driving support control of the vehicle based on the target deceleration; Includes, In the step of setting the target deceleration, When the information regarding the driving environment includes information about a vehicle following the vehicle, if the following vehicle is decelerating, the target deceleration is set to a first target deceleration; if the following vehicle is not decelerating, the target deceleration is set to a second target deceleration, which has a smaller deceleration rate than the first target deceleration. A method for assisting the driving of a vehicle, characterized by the features described above.

2. The method according to claim 1, The aforementioned information regarding the driving environment includes the deceleration of the following vehicle. The first target deceleration is equal to the deceleration of the following vehicle, or is greater than the deceleration of the following vehicle. A method for assisting the driving of a vehicle, characterized by the features described above.

3. A method according to claim 1 or 2, The information regarding the driving environment includes the distance between the vehicle and the following vehicle. If the distance between vehicles is less than or equal to a predetermined distance, the step of setting the target deceleration of the vehicle is prohibited. A method for assisting the driving of a vehicle, characterized by the features described above.

4. A device that assists in the movement of a vehicle, Equipped with a processor that performs various types of information processing, The aforementioned processor, A process for acquiring information about the vehicle's driving environment, including the vehicle's speed and the legal speed limit of the lane in which the vehicle is currently traveling or is scheduled to travel. If the aforementioned driving speed exceeds the aforementioned legal speed limit, the process determines that there is a request for deceleration for the vehicle and sets a target deceleration speed for the vehicle based on the information regarding the driving environment. A process to perform driving support control of the vehicle based on the target deceleration, It is configured to do the following: In the process of setting the target deceleration, the processor If the information regarding the driving environment includes information about a vehicle following the vehicle, and the following vehicle is decelerating, the target deceleration is set to a first target deceleration. If the information regarding the driving environment includes information about a vehicle following the vehicle, and the following vehicle is not decelerating, the target deceleration is set to a second target deceleration, which is less deceleration than the first target deceleration. A vehicle driving support device characterized by the following features.

5. A program that assists in the operation of a vehicle, A process for acquiring information about the vehicle's driving environment, including the vehicle's speed and the legal speed limit of the lane in which the vehicle is currently traveling or is scheduled to travel. If the aforementioned driving speed exceeds the aforementioned legal speed limit, the process determines that there is a request for deceleration for the vehicle and sets a target deceleration speed for the vehicle based on the information regarding the driving environment. A process to perform driving support control of the vehicle based on the target deceleration, Have the computer do it, In the process of setting the target deceleration, When the information regarding the driving environment includes information about a vehicle following the vehicle, and the following vehicle is decelerating, the target deceleration is set to a first target deceleration. If the information regarding the driving environment includes information about a vehicle following the vehicle, and the following vehicle is not decelerating, the target deceleration is set to a second target deceleration, which has a smaller deceleration rate than the first target deceleration. A vehicle driving assistance program characterized by the following features.

Images