Driving support device, driving support method, and program

Abstract

This driving assistance device, when the degree of proximity between a vehicle and a subject object among objects present in front of the vehicle satisfies a first condition, executes braking control for instructing a braking device of the vehicle to stop the vehicle and / or instructs a steering device of the vehicle to avoid contact with the subject object by steering. When the degree of proximity between the subject object and the vehicle satisfies a second condition, the driving assistance device performs a first preliminary action. When the degree of proximity between the subject object and the vehicle satisfies a third condition and it is assessed, at the point when the third condition has been satisfied, that there is no space that allows progress on any course to the side of the subject object after avoidance by steering is performed, the driving assistance device performs a second preliminary action. When the status is such that it is not possible to continue the first preliminary action or the second preliminary action mid-execution, the driving assistance device changes the control mode of the braking control.

Description

Technical Field

[0001] The present invention relates to a driving support device, a driving support method, and a program.

Background Art

[0002] In recent years, inventions of vehicle control devices that perform automatic deceleration control and automatic steering control have been disclosed (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a vehicle capable of performing automatic steering control in addition to automatic deceleration control, the probability of being able to quickly respond to a sudden change in the vehicle situation is high, and the control margin is relatively high. On the other hand, when there is no avoidance space on the side of the target object, automatic steering control becomes difficult, so the control margin is the same as that of a vehicle that only performs automatic deceleration control. In the conventional technology, there are cases where it is not possible to perform operations according to such differences in vehicle situations.

[0005] The present invention has been made in consideration of such circumstances, and one of its objects is to provide a driving support device, a driving support method, and a program that can perform more appropriate driving support according to the vehicle situation.

Means for Solving the Problems

[0006] The driving support device, the driving support method, and the program according to this invention adopt the following configurations. (1) The driving support device according to one aspect of the present invention refers to the output of a detection device that detects the presence of an object existing in front of a vehicle, and when the degree of proximity between the target object among the objects and the vehicle satisfies a first condition, it executes braking control that instructs the braking device of the vehicle to stop the vehicle, and a steering avoidance control unit that instructs the steering device of the vehicle to avoid contact with the target object by steering. The braking control unit includes a first preliminary operation control unit that performs a first preliminary operation when the degree of proximity satisfies a second condition. When the degree of proximity satisfies a third condition and it is determined that there is no space where the vehicle can proceed after performing the avoidance by steering in any of the lanes on the side of the target object at the time when the third condition is satisfied, it further includes a second preliminary operation control unit that performs a second preliminary operation. The first condition is a condition that is satisfied when the degree of proximity is higher than the second condition, and the second condition is a condition that is satisfied when the degree of proximity is higher than the third condition. The braking control unit is a driving support device that changes the control mode of the braking control when the situation where the ongoing first preliminary operation or second preliminary operation cannot be continued occurs.

[0007] (2) In the aspect of (1) above, the situation where the ongoing first preliminary operation or second preliminary operation cannot be continued includes a situation where the performance of the detection device deteriorates.

[0008] (3) In the aspect of (1) or (2) above, when the situation where the ongoing first preliminary operation or second preliminary operation cannot be continued occurs, the braking control unit changes the first condition so that the control to stop the vehicle is more likely to be executed.

[0009] (4) In the aspect of (3) above, when the situation where the ongoing first preliminary operation or second preliminary operation cannot be continued occurs, the braking control unit changes the first condition so that the control to stop the vehicle is executed at a timing earlier than when the first preliminary operation or second preliminary operation can be continued.

[0010] (5) In any one of the aspects (1) to (4) above, when the situation is such that the ongoing first preliminary operation or the second preliminary operation cannot continue, and when control to stop the vehicle is to be executed, the braking control unit instructs the braking device of the vehicle to output a braking force greater than that when the first preliminary operation or the second preliminary operation can continue.

[0011] (6) In any one of the aspects (1) to (5) above, the second preliminary operation is an operation that starts at a timing earlier than that of the first preliminary operation.

[0012] (7) In any one of the aspects (1) to (6) above, at least one of the first preliminary operation and the second preliminary operation is an operation that instructs the braking device to output a braking force smaller than the braking force that the braking control unit instructs the braking device to output.

[0013] (8) In any one of the aspects (1) to (7) above, the braking control unit instructs the output device to perform image display, voice output, or vibration output indicating a change in the control mode of the braking control.

[0014] (9) The driving support method according to another aspect of the present invention is such that a computer refers to the output of a detection device that detects the presence of an object existing in front of a vehicle, and when the degree of proximity between a target object among the objects and the vehicle satisfies a first condition, performs braking control to instruct a braking device of the vehicle to stop the vehicle, and instructs a steering device of the vehicle to avoid contact with the target object by steering, and when the degree of proximity between the target object and the vehicle satisfies a second condition, performs a first preliminary operation, and when the degree of proximity between the target object and the vehicle satisfies a third condition and, at the time when the third condition is satisfied, it is determined that there is no space in which the vehicle can proceed after performing avoidance by steering in any of the lanes on the side of the target object, performs a second preliminary operation, the first condition is a condition that is satisfied when the degree of proximity is higher than that of the second condition, the second condition is a condition that is satisfied when the degree of proximity is higher than that of the third condition, and when a situation occurs in which the ongoing first preliminary operation or the second preliminary operation cannot be continued, changes the control mode of the braking control.

[0015] (10): A program according to another aspect of the present invention causes a computer to refer to the output of a detection device that detects the presence of an object existing in front of a vehicle, and when the degree of proximity between a target object among the objects and the vehicle satisfies a first condition, execute braking control to instruct the braking device of the vehicle to stop the vehicle, and instruct the steering device of the vehicle to avoid contact with the target object by steering, and when the degree of proximity between the target object and the vehicle satisfies a second condition, cause a first preliminary operation to be performed, and when the degree of proximity between the target object and the vehicle satisfies a third condition and, at the time when the third condition is satisfied, it is determined that there is no space in which the vehicle can proceed after performing the avoidance by steering in any of the lanes on the side of the target object, cause a second preliminary operation to be performed, the first condition is a condition satisfied when the degree of proximity is higher than the second condition, the second condition is a condition satisfied when the degree of proximity is higher than the third condition, and when a situation occurs in which the ongoing first preliminary operation or the second preliminary operation cannot be continued, cause the control mode of the braking control to be changed.

Advantages of the Invention

[0016] According to the aspects (1) to (10) above, more appropriate driving assistance can be provided according to the situation of the vehicle.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0018] Hereinafter, embodiments of the driving support device, driving support method, and program of the present invention will be described with reference to the drawings.

[0019] [Overall Configuration] FIG. 1 is a configuration diagram of a vehicle M equipped with the driving support device 100 according to the embodiment. The vehicle M is, for example, a two-wheeled, three-wheeled, or four-wheeled vehicle, and its drive source is an internal combustion engine such as a diesel engine or a gasoline engine, an electric motor, or a combination thereof. The electric motor operates using the electric power generated by a generator connected to the internal combustion engine, or the discharge power of a secondary battery or a fuel cell.

[0020] The vehicle M is equipped with, for example, a camera 10, a radar device 12, a LIDAR (Light Detection and Ranging) 14, an object recognition device 16, a HMI (Human Machine Interface) 30, a vehicle sensor 40, a driving operator 80, a driving support device 100, a traveling driving force output device 200, a brake device 210, and a steering device 220. These devices and equipment are connected to each other by a multiplex communication line such as a CAN (Controller Area Network) communication line, a serial communication line, a wireless communication network, or the like. Note that the configuration shown in FIG. 1 is merely an example, and a part of the configuration may be omitted, or another configuration may be added. The HMI 30 is an example of an "output device". The brake device 210 is an example of a "braking device". The steering device 220 is an example of a "steering device".

[0021] The camera 10 is a digital camera that uses a solid-state imaging device such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor). The camera 10 is attached to an arbitrary location on a vehicle (hereinafter referred to as vehicle M) on which the vehicle system 1 is mounted. When imaging the front, the camera 10 is attached to the upper part of the front windshield, the back surface of the rearview mirror, or the like. The camera 10 periodically repeats imaging the periphery of the vehicle M, for example. The camera 10 may be a stereo camera.

[0022] The radar device 12 radiates radio waves such as millimeter waves around the vehicle M, and detects radio waves (reflected waves) reflected by an object to detect at least the position (distance and azimuth) of the object. The radar device 12 is attached to an arbitrary location on the vehicle M. The radar device 12 may detect the position and speed of an object by an FM-CW (Frequency Modulated Continuous Wave) method.

[0023] The LIDAR 14 irradiates light (or electromagnetic waves with a wavelength close to light) around the vehicle M and measures scattered light. The LIDAR 14 detects the distance to an object based on the time from light emission to light reception. The light to be irradiated is, for example, pulsed laser light. The LIDAR 14 is attached to an arbitrary location on the vehicle M.

[0024] The object recognition device 16 performs sensor fusion processing on the detection results from some or all of the camera 10, the radar device 12, and the LIDAR 14 to recognize the position, type, speed, etc. of the object. The object recognition device 16 outputs the recognition result to the driving support device 100. The object recognition device 16 may output the detection results of the camera 10, the radar device 12, and the LIDAR 14 to the driving support device 100 as they are. The object recognition device 16 may be omitted from the vehicle system 1. Some or all of the camera 10, the radar device 12, the LIDAR 14, and the object recognition device 16 are an example of a "detection device".

[0025] In addition, the object recognition device 16 may acquire the reliability of the recognized object (an index value indicating certainty). In this case, the object recognition device 16, for example, refers to feature information (such as contour, shape, size, color) obtained by analyzing an image captured by the camera 10 (hereinafter referred to as a camera image) and a model for pattern matching defined in advance, and acquires the reliability of the object included in the image through matching processing. The model is, for example, a trained model such as a DNN (Deep Neural Network) that is trained to take the feature information of the analysis result as input and output the type and reliability of the object, etc., but is not limited thereto. The model may be stored, for example, in a storage unit (not shown) of the object recognition device 16, or may be acquired from an external device via a communication device (not shown) mounted on the vehicle M. Further, the model may be appropriately updated by feedback control of the recognition result, update data from an external device, etc.

[0026] The HMI 30 presents various information to the passengers of the vehicle M and accepts input operations by the passengers. The HMI 30 includes various display devices, speakers, buzzers, vibration generators (vibrators), touch panels, switches, keys, etc.

[0027] The vehicle sensor 40 includes a vehicle speed sensor that detects the speed of the vehicle M, an acceleration sensor that detects acceleration, a yaw rate sensor that detects the angular velocity around the vertical axis, an azimuth sensor that detects the orientation of the vehicle M, etc.

[0028] The navigation device 50 has, for example, a GNSS (Global Navigation Satellite System) receiver, a guidance control unit, a storage unit that stores map information, and the like. The GNSS receiver identifies the position of the vehicle M based on signals received from GNSS satellites. The position of the vehicle M may be identified or supplemented by an INS (Inertial Navigation System) that utilizes the output of the vehicle sensor 40. The guidance control unit determines, for example, a route from the position of the vehicle M identified by the GNSS receiver (or an arbitrary input position) to the destination input by the occupant with reference to the map information, and causes the HMI 30 to output guidance information so that the vehicle M travels along the route. The map information is, for example, information in which the road shape is represented by links indicating roads and nodes connected by the links. The map information may include the number of lanes and curvature of the road, POI (Point Of Interest) information, information on road markings (e.g., shape, line type, color), and the like. The navigation device 50 may transmit the current position and destination of the vehicle M to the navigation server via a communication device and acquire a route from the navigation server.

[0029] The driving operator 80 includes, for example, an accelerator pedal, a brake pedal, a steering wheel, a shift lever, and other operators. A sensor for detecting the operation amount or the presence or absence of an operation is attached to the driving operator 80, and the detection result is output to some or all of the driving force output device 200, the brake device 210, and the steering device 220.

[0030] The driving force output device 200 outputs a driving force (torque) for the vehicle to travel to the drive wheels. The driving force output device 200 includes, for example, a combination of an internal combustion engine, an electric motor, and a transmission, and an ECU (Electronic Control Unit) that controls these. The ECU controls the above configuration according to information input from the driving support device 100 or information input from the driving operator 80.

[0031] The braking device 210 includes, for example, a brake caliper, a cylinder that transmits hydraulic pressure to the brake caliper, an electric motor that generates hydraulic pressure in the cylinder, and an ECU. The ECU controls the electric motor according to information input from the driving assistance device 100 or information input from the driving operator 80, so that braking torque corresponding to the braking operation is output to each wheel. The braking device 210 may include, as a backup, a mechanism that transmits the hydraulic pressure generated by the operation of the brake pedal included in the driving operator 80 to the cylinder via the master cylinder. Note that the braking device 210 is not limited to the configuration described above, and may be an electronically controlled hydraulic braking device that controls an actuator according to information input from the driving assistance device 100 and transmits the hydraulic pressure of the master cylinder to the cylinder.

[0032] The steering device 220 includes, for example, a steering ECU and an electric motor. The electric motor acts on, for example, a rack and pinion mechanism to change the direction of the steered wheels. The steering ECU drives the electric motor according to information input from the driving assistance device 100 or information input from the driving operator 80 to change the direction of the steered wheels.

[0033] [Driving Assistance Device] The driving support device 100 includes, for example, a braking control unit 110, a steering avoidance control unit 120, a second standby operation control unit 130, and a determination unit 140. The braking control unit 110 includes a first standby operation control unit 112, and the second standby operation control unit 130 includes a steering avoidance determination unit 132. These functional units are realized, for example, when a hardware processor such as a CPU (Central Processing Unit) executes a program (software). Also, some or all of these components may be realized by hardware (including a circuit unit; circuitry) such as an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a GPU (Graphics Processing Unit), or may be realized by the cooperation of software and hardware. The program may be stored in advance in a storage device (a storage device having a non-transitory storage medium) such as an HDD or a flash memory of the driving support device 100, or may be stored in a removable storage medium such as a DVD or a CD-ROM, and may be installed in the HDD or the flash memory of the driving support device 100 when the storage medium (non-transitory storage medium) is mounted on a drive device.

[0034] Instructions from the driving support device 100 to the traveling driving force output device 200, the brake device 210, and the steering device 220 are set inside the traveling driving force output device 200, the brake device 210, and the steering device 220 so as to be executed with priority over the detection results from the driving operation unit 80. Regarding braking, when the braking force based on the operation amount of the brake pedal is greater than the instruction from the driving support device 100, it may be set to give priority to the latter. Also, as a mechanism for giving priority to the execution of the instruction from the driving support device 100, the communication priority in the in-vehicle LAN (Local Area Network) may be used.

[0035] FIG. 2 is a diagram showing an overview of the functions of the driving support device 100. Hereinafter, each part of the driving support device 100 will be described with reference to this figure and FIG. 1. In FIG. 2, the vehicle M is traveling on a three-lane road extending in the X-axis direction in the figure, and is in the central lane L2. D M is the traveling direction of the vehicle M. The Y-axis direction in the figure is the road width (lane width) direction. The Z-axis direction in the figure is the vertical direction with respect to the vehicle M or the road surface (horizontal plane). Hereinafter, the XYZ coordinate system may be used for explanation as necessary.

[0036] The braking control unit 110 refers to the output of a detection device (described above) that detects the presence of an object existing in front of the vehicle M, and when the degree of proximity between the target object TO and the vehicle M among the objects satisfies the first condition, it instructs at least the braking device 210 among the braking device 210 and the traveling driving force output device 200 to decelerate and stop the vehicle M, and executes braking control. The target object TO is an object that is on the same road as the vehicle M and on the traveling direction side of the vehicle M, and is an object that the vehicle M should avoid contact with, excluding objects that can be crossed such as manholes. The braking control unit 110 extracts such an object and sets it as the target object TO. In the example of FIG. 2, among the plurality of vehicles traveling in the same lane L2 in front of the vehicle M and at the rearmost position (the other vehicle closest to the vehicle M) is set as the target object TO. The road surface is, for example, a lane. The lane is partitioned by, for example, a partition line (for example, a road partition line) recognized by a detection device or the like. Also, the lane may be a virtual lane virtually set by the vehicle M on a road surface where there is no road partition line. The same applies to the following description.

[0037] "Degree of proximity" is represented by various index values indicating the degree of proximity between objects. For example, "degree of proximity" is the TTC (Time To Collision), which is an index value obtained by dividing the distance by the relative speed (assuming the direction of approaching each other as positive). When the relative speed is negative (the direction of moving away from each other), the TTC is set to infinity for the sake of argument. The smaller the value of TTC, the higher the "degree of proximity". And satisfying the "first condition" means, for example, that the TTC is less than the first threshold Th1. The first threshold Th1 is, for example, a value of about 1 comma number [sec]. Instead of TTC, index values having similar properties, such as headway time, distance, and other index values, may be used as the "degree of proximity". Also, a TTC adjusted considering acceleration and jerk may be used as the "degree of proximity". In the following description, the "degree of proximity" will be described as being the TTC.

[0038] When the braking control unit 110 satisfies the first condition (when the TTC is less than the first threshold Th1), for example, it instructs the brake device 210 and / or the driving force output device 200 to output a braking force for decelerating the vehicle M at the first deceleration B1. The first deceleration B1 is, for example, a deceleration of about 0 comma number [G] (close to 1). Thereby, the braking control unit 110 quickly decelerates and stops the vehicle M to avoid contact with the target object TO. The function of obtaining the brake output, the regenerative control amount, the engine brake amount, etc. from the instructed deceleration is possessed by the ECUs of the brake device 210 and the driving force output device 200, and the ECUs determine each control amount based on the instructed deceleration and the speed of the vehicle M. This is a known technology and a detailed description thereof will be omitted.

[0039] Also, for example, when the situation becomes such that the ongoing operation cannot continue during the execution of the first preliminary operation or the second preliminary operation, the braking control unit 110 changes the control mode of the braking control for stopping the vehicle M. Details of the functions of the braking control unit 110 described above will be described later. Also, the operation of the first preliminary operation control unit 112 will be described later, and first, the steering avoidance control unit 120 will be described.

[0040] FIG. 3 is a diagram showing an example of an operation scene of the steering avoidance control unit 120. When it is determined that the braking control unit 110 has difficulty in stopping the vehicle M in front of the target object TO, the steering avoidance control unit 120 determines whether there is a space in which the vehicle M can travel in the lane (for example, lanes L1 and L3) on the side of the target object TO. When it is determined that there is a space, an avoidance trajectory ET is generated, and the steering device 220 is instructed to make the vehicle M travel along the avoidance trajectory ET (steering avoidance). For example, the steering avoidance control unit 120 determines whether there is an object in the lateral region extending from slightly in front of to behind the target object TO on both sides of the target object TO, such as the regions A2L and A2R shown in FIG. 3. When it is determined that there is no object, it is determined that there is a space in which the vehicle M can travel in the lane on the side of the target object TO. The determination as to whether the braking control unit 110 has difficulty in stopping the vehicle M in front of the target object TO may be made by the braking control unit 110 or by the steering avoidance control unit 120. The steering avoidance control unit 120 recognizes the boundary of the lane by recognizing, for example, the white line in the camera image or the dividing line that divides the lane such as the road shoulder. If there is no area A2L or A2R where the vehicle can travel in the first place, for example, if either lane L1 or L3 does not exist, it may be determined that there is an object in the area.

[0041] Steering avoidance is performed, for example, when the target object TO decelerates unexpectedly, or when an object other than the recognized target object TO interrupts between the vehicle M and the target object TO and is set as a new target object TO, etc., in a situation where a sudden change occurs in the vehicle's surrounding environment. In such a situation, there is a possibility that the deceleration calculated in advance to stop in front of the target object TO may not be sufficient to respond, but by having the function of steering avoidance, the probability of being able to respond to a sudden change in the surrounding environment of the vehicle M can be increased.

[0042] [Preparatory operation] Hereinafter, the processing of the first preparatory operation control unit 112 and the second preparatory operation control unit 130 will be described. FIG. 4 is a diagram for explaining the preparatory operation.

[0043] When the degree of proximity between the target object TO and the vehicle M satisfies the second condition (for example, when the TTC is less than the second threshold Th2), the first preliminary operation control unit 112 performs a first preliminary operation to notify the driver of the vehicle M of the presence of the target object TO. The first preliminary operation is, for example, an operation of instructing the brake device 210 and / or the traveling driving force output device 200 to output a braking force for decelerating the vehicle M at the second deceleration B2 from when the TTC becomes less than the second threshold Th2 until it becomes less than the first threshold Th1. The second deceleration B2 is a deceleration smaller (closer to zero) than the first deceleration B1. The second threshold Th2 is a value larger than the first threshold Th1. Therefore, the first condition is a condition satisfied when the degree of proximity is higher than that of the second condition.

[0044] When the degree of proximity between the target object TO and the vehicle M satisfies the third condition (for example, when the TTC is less than the third threshold Th3), and when it is determined that there is no available space for traveling after performing a steering avoidance to either side of the road on the side of the target object TO at the time when the third condition is satisfied, the second preliminary operation control unit 130 performs a second preliminary operation to notify the driver of the vehicle M of the presence of the target object TO. The determination regarding the available space for traveling is made by the steering avoidance determination unit 132. The third threshold Th3 is a value larger than the second threshold Th2. Therefore, the second condition is a condition satisfied when the degree of proximity is higher than that of the third condition.

[0045] The steering avoidance feasibility determination unit 132 determines, for example, when the TTC becomes less than the third threshold Th3, whether an object exists in a lateral region extending from slightly in front of to behind the target object TO on both sides of the target object TO, such as the regions A1L and A1R shown in FIG. 4. If no object exists, it is determined that there is a space in which the vehicle M can travel in the lane beside the target object TO. Each of the regions A1L and A1R is set to a larger region than each of the regions A2L and A2R, for example, considering future uncertain factors. Similar to the steering avoidance control unit 120, the steering avoidance feasibility determination unit 132 also recognizes the boundary of the lane by recognizing lane lines such as white lines or road shoulders in the camera image. If either of the drivable regions A1L and A1R does not exist, for example, if either lane L1 or L3 does not exist, it may be determined that an object exists in that region. In the example of FIG. 4, since no object exists in the region A1R, the steering avoidance feasibility determination unit 132 determines that there is a space in which the vehicle M can travel in the lane beside the target object TO.

[0046] The second preliminary operation is, for example, an operation of first instructing the brake device 210 and / or the driving force output device 200 to output a braking force for decelerating the vehicle M at the third deceleration B3, and then instructing the brake device 210 and / or the driving force output device 200 to output a braking force for decelerating the vehicle M at the fourth deceleration B4, from when the TTC becomes less than the third threshold Th3 until it becomes less than the first threshold Th1. The third deceleration B3 is, for example, a deceleration smaller (closer to zero) than the second deceleration B2, and the fourth deceleration B4 is a deceleration larger than or approximately the same as the second deceleration and smaller than the first deceleration B1. The timing for switching from the third deceleration B3 to the fourth deceleration B4 may be arbitrarily set.

[0047] In this way, the second preliminary operation is started at a timing earlier than the first preliminary operation and is performed in multiple stages. As described above, in a situation where steering avoidance is possible, the probability of quickly responding to a sudden change in the surrounding environment of the vehicle is high, and the control margin is relatively high. On the other hand, when there is no avoidance space on the side of the target object, even if the vehicle is equipped with a steering avoidance function, it becomes difficult to execute it. Therefore, the control margin is the same as that of a vehicle that can only perform automatic stop. That is, in a situation where steering avoidance is difficult, it is preferable to give a warning to the driver of the vehicle M earlier and more effectively than in a situation where steering avoidance is possible. According to the present embodiment, by starting the second preliminary operation at a timing earlier than the first preliminary operation and performing it in multiple stages, an appropriate preliminary operation according to the surrounding situation of the target object can be performed.

[0048] The determination unit 140 determines whether or not a situation occurs during the execution of the first preliminary operation or the second preliminary operation in which the ongoing operation cannot be continued. The determination result of the determination unit 140 is output to the braking control unit 110 and the second preliminary operation control unit 130. Details of the function of the determination unit 140 will be described later.

[0049] FIG. 5 is a flowchart showing an example of the flow of processing executed by the driving support device 100.

[0050] First, the braking control unit 110 identifies the target object TO (step S1). Next, the second preliminary operation control unit 130 determines whether or not the TTC between the vehicle M and the target object TO is less than the third threshold Th3 (step S2). When the TTC between the vehicle M and the target object TO is greater than or equal to the third threshold Th3, the process returns to step S1.

[0051] When it is determined that the TTC between the vehicle M and the target object TO is less than the third threshold Th3, the steering avoidance determination unit 132 of the second preliminary operation control unit 130 determines whether or not there is a space in which the vehicle M can travel on the road beside the target object TO (step S3).

[0052] When it is determined that there is no space for the vehicle M to travel on the lane beside the target object TO, the second preliminary operation control unit 130 executes the second preliminary operation (step S4). Next, the second preliminary operation control unit 130 determines whether the TTC between the vehicle M and the target object TO has increased to be equal to or greater than the third threshold Th3 (step S5). When it is determined that the TTC between the vehicle M and the target object TO has increased to be equal to or greater than the third threshold Th3, the process returns to step S1.

[0053] When it is not determined that the TTC between the vehicle M and the target object TO has increased to be equal to or greater than the third threshold Th3, the braking control unit 110 determines whether the TTC between the vehicle M and the target object TO is less than the first threshold Th1 (step S6). When it is determined that the TTC between the vehicle M and the target object TO is equal to or greater than the first threshold Th1, the process returns to step S3. When an affirmative determination is obtained in step S3, the second preliminary operation is stopped, and the processes after step S8 are executed. When it is determined that the TTC between the vehicle M and the target object TO is less than the first threshold Th1, the braking control unit 110 outputs a braking force for decelerating the vehicle M at the first deceleration B1 to the braking device 210 and / or the driving force output device 200 to decelerate and stop the vehicle M (step S7). At this time, as described above, steering avoidance may be performed instead of (or in addition to) decelerating and stopping the vehicle M.

[0054] When an affirmative determination is obtained in step S3, that is, when the TTC between the vehicle M and the target object TO is less than the third threshold Th3 and there is a space for the vehicle M to travel on the lane beside the target object TO, the first preliminary operation control unit 112 of the braking control unit 110 determines whether the TTC between the vehicle M and the target object TO is less than the second threshold Th2 (step S8). When it is determined that the TTC between the vehicle M and the target object TO is equal to or greater than the second threshold Th2, the process returns to step S1.

[0055] When it is determined that the TTC between the vehicle M and the target object TO is less than the second threshold Th2, the first preliminary operation control unit 112 executes the first preliminary operation (step S9). Next, the first preliminary operation control unit 112 determines whether the TTC between the vehicle M and the target object TO has increased to be equal to or greater than the second threshold Th2 (step S10). When it is determined that the TTC between the vehicle M and the target object TO has increased to be equal to or greater than the second threshold Th2, the process returns to step S1.

[0056] When it is not determined that the TTC between the vehicle M and the target object TO has increased to be equal to or greater than the second threshold Th2, the braking control unit 110 determines whether the TTC between the vehicle M and the target object TO is less than the first threshold Th1 (step S11). When it is determined that the TTC between the vehicle M and the target object TO is equal to or greater than the first threshold Th1, the process returns to step S3. When a negative determination is obtained in step S3, the first preliminary operation is stopped, and the processes after step S4 are executed. When it is determined that the TTC between the vehicle M and the target object TO is less than the first threshold Th1, the braking control unit 110 outputs the first deceleration B1 to the braking device 210 and / or the traveling driving force output device 200 to decelerate and stop the vehicle M (step S7).

[0057] [Braking control in a situation where the first preliminary operation or the second preliminary operation cannot continue] Next, the braking control when the operation being executed cannot continue (until the operation is completed) during the execution of the second preliminary operation or the first preliminary operation described above will be described. FIG. 6 is a diagram for explaining the first braking control when the first preliminary operation or the second preliminary operation being executed cannot continue. In the following description, the content described with reference to FIG. 4 is omitted, and the description will focus on the differences from FIG. 4. The same applies to FIG. 7 described later.

[0058] First, during the execution of the first preliminary operation or the second preliminary operation, the determination unit 140 determines whether the ongoing operation can no longer continue. The situation where the ongoing first preliminary operation or second preliminary operation cannot be executed includes, for example, the situation where the performance of the detection device deteriorates. The deterioration of performance means, for example, that the detection device could detect up to a predetermined distance (e.g., about 80 to 100 [m] ahead) from the vehicle M under normal conditions, but due to some reason, it cannot detect up to the predetermined distance (e.g., it can only detect up to about 30 to 50 [m] ahead from the vehicle M). Also, the deterioration of performance may mean, for example, that the average luminance of the camera image is below the threshold value, or the reliability of the detection device (e.g., the probability of the object obtained by the object recognition device 16) is below the threshold value. Further, the deterioration of performance may mean, for example, that among a plurality of vehicles existing within a predetermined distance in front of the vehicle M, vehicles other than the target object TO cannot be recognized, or the recognition reliability is below the threshold value. The performance deterioration may include, for example, the case where it continuously deteriorates due to deterioration or failure of the detection device, or the case where it temporarily deteriorates due to the influence of the surrounding environment (e.g., heavy rain, sunlight) or the adhesion of dust to the detection device.

[0059] Based on the detection result of the detection device, the determination unit 140 determines whether the performance of the detection device has deteriorated according to the above-described determination conditions. Further, the determination unit 140 may obtain the degree of performance deterioration of the detection device based on the difference from each reference value (threshold value) of the above-described determination conditions and the reliability.

[0060] For example, when the determination unit 140 determines that the performance of the detection device has deteriorated, it determines that the ongoing first preliminary operation or second preliminary operation cannot continue. Also, when the determination unit 140 determines that the performance of the detection device has not deteriorated, it determines that the ongoing first preliminary operation or second preliminary operation can continue. When the ongoing first preliminary operation or second preliminary operation can continue, for example, the control as shown in FIG. 4 described above is executed.

[0061] When it is determined by the determination unit 140 that the situation is such that the ongoing first preliminary operation or second preliminary operation cannot continue, if the first preliminary operation control unit 112 is executing the first preliminary operation, it stops that operation, and if the second preliminary operation control unit 130 is executing the second preliminary operation, it stops that operation. Also, when it is determined by the determination unit 140 that the situation is such that the ongoing first preliminary operation or second preliminary operation cannot continue, the braking control unit 110 changes the first condition so that control to stop the vehicle M is more likely to be executed. For example, the braking control unit 110 changes the first condition so that braking control to stop the vehicle M is executed at a timing earlier than when the first preliminary operation or second preliminary operation can continue (hereinafter referred to as normal times).

[0062] For example, as shown in FIG. 6, the braking control unit 110 sets a changed threshold value Th1# that is larger than the value of the first threshold Th1 compared with the TTC, and when the TTC is less than the changed threshold value Th1#, it outputs a braking force to decelerate the vehicle M at the first deceleration B1 and instructs the brake device 210 and / or the traveling driving force output device 200 to do so. Note that the changed threshold value Th1# is a value smaller than the second threshold Th2. Regarding how much the changed threshold value Th1# is increased from the first threshold Th1, for example, it may be set based on the speed of the vehicle M or the road conditions, or it may be set based on the degree of performance degradation of the detection device determined by the determination unit 140.

[0063] Thereby, braking control can be executed at a timing earlier than normal times, and contact with the target object TO can be more reliably prevented. For example, in a situation where the performance of the detection device has deteriorated, by changing to braking control with higher safety, more appropriate driving support can be provided.

[0064] Also, instead of (or in addition to) executing braking control to stop the vehicle M at a timing earlier than normal times, the braking control unit 110 may increase the value of the first deceleration B1 during braking control.

[0065] FIG. 7 is a diagram for explaining a second braking control when the ongoing first preliminary operation or second preliminary operation cannot continue. In the second braking control shown in FIG. 7, when the ongoing first preliminary operation or second preliminary operation cannot continue and the first condition is satisfied (when TTC is less than the first threshold Th1), for example, the braking control unit 110 instructs the brake device 210 and / or the driving force output device 200 to output a braking force for decelerating the vehicle M at a deceleration B1# greater than the first deceleration B1. Regarding how much greater the deceleration B1# is than the first deceleration B1, it may be set based on, for example, the speed of the vehicle M or the road conditions, or it may be set based on the degree of performance degradation of the detection device determined by the determination unit 140.

[0066] Thereby, the vehicle M can be stopped within a shorter distance than normal, and contact with the target object TO can be more reliably prevented. For example, in a situation where the performance of the detection device has deteriorated, more appropriate driving assistance can be provided by changing to a braking control with higher safety.

[0067] Note that the braking control unit 110 may combine the above-described first braking control and second braking control and instruct the brake device 210 and / or the driving force output device 200 to output a braking force for decelerating at the deceleration B1# when TTC is less than the change threshold Th1#.

[0068] FIG. 8 is a flowchart showing an example of a braking control process based on the execution status of the first preliminary operation or second preliminary operation. The process in FIG. 8 is a process that is repeatedly executed at a predetermined period or timing, for example, during the execution of the process shown in FIG. 5.

[0069] In the example of FIG. 8, the determination unit 140 determines whether the first preliminary operation or the second preliminary operation is being executed (step S21). The execution of the first preliminary operation corresponds to, for example, the process of step S9 in FIG. 5, and the execution of the second preliminary operation corresponds to, for example, the process of step S4 in FIG. 5. When it is determined that the first preliminary operation or the second preliminary operation is being executed, the determination unit 140 determines whether the situation is such that the ongoing operation cannot continue (step S22). When it is determined that the situation is one where continuation is not possible, the braking control unit 110 changes the control mode of the braking control for stopping the vehicle M in the process of step S7 shown in FIG. 5 (step S23). Thereby, the processing of this flowchart ends. Also, when it is determined in the process of step S21 that neither the first preliminary operation nor the second preliminary operation is being executed, or when it is determined in the process of step S22 that the situation is not one where the ongoing operation cannot continue (the situation is one where continuation is possible), the processing of this flowchart ends.

[0070] Note that when the process of step S23 in FIG. 8 is executed, the subsequent processing in FIG. 8 does not necessarily need to be repeatedly executed. Also, in the process of step S22, after it is determined that the situation is one where the ongoing operation cannot continue, if it is determined within a predetermined time that the situation is not one where the ongoing operation cannot continue (the situation is one where continuation is possible), and the changed braking control has not been executed, the braking control unit 110 may perform a process of restoring the changed control mode.

[0071] <Modification Example> In the above-described embodiment, in either the first preliminary operation or the second preliminary operation, instead of outputting braking force, display for alerting by the HMI 30, voice output, vibration output, etc. may be performed. In this case, as an example where the second preliminary operation is performed in multiple steps, instead of outputting braking force step by step while changing the deceleration rate as described above, the degree of attention (contrast, brightness, color, etc.) of the first display screen and the display screens after the second time are made different, the content or volume of the first voice output and the voice outputs after the second time are made different, the vibration output after the second time is made larger than the first vibration output, etc. may be mentioned.

[0072] Further, when changing the control mode of the braking control from the normal mode, the braking control unit 110 may instruct the HMI 30 to perform an image display, an audio output, or a vibration output corresponding to information indicating the change of the control mode of the braking control to the passengers of the vehicle M. Thereby, even when the braking control of the vehicle M different from the normal time is executed, the anxiety of the passengers can be reduced by notifying the passengers.

[0073] In the above embodiment, when the branch road to the destination set in the navigation device 50 is on either the left or right side of the lane in which the vehicle M is traveling, a lane change may be forcibly performed during the preliminary operation. By doing so, as a result, the vehicle M can be moved in the direction approaching the destination, and the object that becomes the target object can be guided to a state where it is not near the vehicle M.

[0074] Further, in the above embodiment, instead of determining whether the operation being executed can continue in a situation where the first preliminary operation or the second preliminary operation cannot continue during the execution of the first preliminary operation or the second preliminary operation, before the execution of the first preliminary operation or the second preliminary operation, it may be determined whether the first preliminary operation or the second preliminary operation can be executed. In this case, when the first preliminary operation or the second preliminary operation cannot be executed due to a performance degradation of the detection device or the like, the braking control unit 110 changes the control mode of the braking control as described above.

[0075] According to the embodiment described above, in the driving assistance device 100, referring to the output of a detection device that detects the presence of an object existing in front of the vehicle M, when the degree of proximity between the target object among the objects and the vehicle satisfies the first condition, a braking control unit 110 that executes braking control to instruct the braking device of the vehicle to stop the vehicle, and a steering avoidance control unit 120 that instructs the steering device of the vehicle M to avoid contact with the target object by steering are provided. The braking control unit 110 includes a first preliminary operation control unit 112 that performs a first preliminary operation when the degree of proximity satisfies the second condition. When the degree of proximity satisfies the third condition and it is determined that there is no available space for traveling after steering avoidance has been performed in any of the lanes on the side of the target object at the time when the third condition is satisfied, the braking control unit 110 further includes a second preliminary operation control unit 130 that performs a second preliminary operation. The first condition is a condition that is satisfied when the degree of proximity is higher than the second condition, and the second condition is a condition that is satisfied when the degree of proximity is higher than the third condition. The braking control unit 110 can perform more appropriate driving assistance according to the situation of the vehicle by changing the control mode of the braking control when the situation where the ongoing first preliminary operation or second preliminary operation cannot be continued occurs.

[0076] Specifically, according to the embodiment, for example, when the first preliminary operation or the second preliminary operation cannot be performed (not implemented) due to the performance limit of the vehicle M or the like during the implementation of the first preliminary operation or the second preliminary operation, the conditions (such as profiles) are changed so that the braking control by the braking control unit 110 is more likely to be executed, the priority of the braking control is increased, the timing of executing the braking control is advanced, or the deceleration G is increased, thereby enabling the vehicle to be controlled on the safer side.

[0077] The embodiment described above can be expressed as follows. A storage medium that stores computer-readable instructions, A processor connected to the storage medium, and the processor executing the computer-readable instructions to: refer to the output of a detection device that detects the presence of an object existing in front of the vehicle, and when the degree of proximity between the target object among the objects and the vehicle satisfies a first condition, execute braking control to instruct the braking device of the vehicle to stop the vehicle, and perform one or both of instructing the steering device of the vehicle to avoid contact with the target object by steering; when the degree of proximity between the target object and the vehicle satisfies a second condition, perform a first preliminary operation; when the degree of proximity between the target object and the vehicle satisfies a third condition and, at the time when the third condition is satisfied, it is determined that there is no space in which the vehicle can proceed after performing avoidance by steering in any of the lanes on the side of the target object, perform a second preliminary operation; the first condition is a condition that is satisfied when the degree of proximity is higher than the second condition; the second condition is a condition that is satisfied when the degree of proximity is higher than the third condition; when the situation becomes such that the first preliminary operation or the second preliminary operation being executed cannot be continued, change the control mode of the braking control; a driving assistance device.

[0078] As described above, the embodiments for carrying out the present invention have been described using the embodiments, but the present invention is not limited to such embodiments at all, and various modifications and substitutions can be made without departing from the gist of the present invention.

Explanation of Signs

[0079] 10 Camera 12 Radar device 14 LIDAR 16 Object recognition device 80 Driving operator 100 Driving assistance device 110 Brake control unit 112 First standby operation control unit 120 Steering avoidance control unit 130 Second standby operation control unit 132 Steering avoidance feasibility determination unit 140 Determination unit 200 Travel driving force output device 210 Brake device 220 Steering device

Claims

1. Referring to the output of a detection device that detects the presence of an object existing in front of a vehicle, when the degree of proximity between a target object among the objects and the vehicle satisfies a first condition, a braking control unit that instructs a braking device of the vehicle to stop the vehicle and executes braking control; A steering avoidance control unit that instructs a steering device of the vehicle to avoid contact with the target object by steering; Comprising: The braking control unit includes a first preliminary operation control unit that performs a first preliminary operation when the degree of proximity satisfies a second condition; When the degree of proximity satisfies a third condition and, at the time when the third condition is satisfied, it is determined that there is no space in which the vehicle can proceed after performing avoidance by steering in any of the lanes on the side of the target object, the braking control unit further includes a second preliminary operation control unit that performs a second preliminary operation; The first condition is a condition that is satisfied when the degree of proximity is higher than the second condition; The second condition is a condition that is satisfied when the degree of proximity is higher than the third condition; The braking control unit changes the control mode of the braking control when the situation is such that the ongoing first preliminary operation or second preliminary operation cannot continue; A driving assistance device.

2. The situation where the ongoing first preliminary operation or second preliminary operation cannot continue includes a situation where the performance of the detection device deteriorates. The driving assistance device according to Claim 1.

3. The braking control unit changes the first condition so that control for stopping the vehicle is more likely to be executed when the situation is such that the ongoing first preliminary operation or second preliminary operation cannot continue. The driving assistance device according to Claim 1 or 2.

4. The braking control unit changes the first condition so that control for stopping the vehicle is executed at a timing earlier than when the ongoing first preliminary operation or second preliminary operation can continue when the situation is such that the ongoing first preliminary operation or second preliminary operation cannot continue. The driving assistance device according to Claim 3.

5. When the situation is such that the ongoing first preliminary operation or second preliminary operation cannot continue and when control for stopping the vehicle is to be executed, the braking control unit instructs the braking device of the vehicle to output a braking force greater than when the first preliminary operation or second preliminary operation can continue. The driving assistance device according to any one of Claims 1 to 4.

6. The second preliminary operation is an operation that starts at a timing earlier than the first preliminary operation. The driving support device according to any one of claims 1 to 5.

7. At least one of the first preliminary operation and the second preliminary operation is an operation of instructing the braking device to output a braking force smaller than the braking force that the braking control unit instructs the braking device to output. The driving support device according to any one of claims 1 to 6.

8. The braking control unit instructs an output device to perform an image display, an audio output, or a vibration output indicating a change in the control mode of the braking control. The driving support device according to any one of claims 1 to 7.

9. A computer refers to the output of a detection device that detects the presence of an object existing in front of the vehicle, and when the degree of proximity between the target object among the objects and the vehicle satisfies a first condition, executes braking control to instruct the braking device of the vehicle to stop the vehicle and / or instruct the steering device of the vehicle to avoid contact with the target object by steering, when the degree of proximity between the target object and the vehicle satisfies a second condition, performs a first preliminary operation, when the degree of proximity between the target object and the vehicle satisfies a third condition and, at the time when the third condition is satisfied, it is determined that there is no space where the vehicle can proceed after performing the avoidance by steering in any of the lanes on the side of the target object, performs a second preliminary operation, The first condition is a condition that is satisfied when the degree of proximity is higher than that of the second condition. The second condition is a condition that is satisfied when the degree of proximity is higher than that of the third condition. When the situation becomes such that the ongoing first preliminary operation or second preliminary operation cannot continue, changes the control mode of the braking control. Driving support method.

10. On a computer refer to the output of a detection device that detects the presence of an object existing in front of the vehicle, and when the degree of proximity between the target object among the objects and the vehicle satisfies a first condition, cause to execute braking control to instruct the braking device of the vehicle to stop the vehicle and / or cause to instruct the steering device of the vehicle to avoid contact with the target object by steering, when the degree of proximity between the target object and the vehicle satisfies a second condition, cause to perform a first preliminary operation. When the degree of proximity between the target object and the vehicle satisfies the third condition, and when it is determined that there is no space available for progress after performing avoidance by steering in any of the lanes on the side of the target object at the time when the third condition is satisfied, the second preliminary operation is caused to be performed. The first condition is a condition that is satisfied when the degree of proximity is higher than that of the second condition. The second condition is a condition that is satisfied when the degree of proximity is higher than that of the third condition. When the situation becomes such that the first preliminary operation or the second preliminary operation being executed cannot be continued, the control mode of the braking control is changed. Program.

Images