Driving assistance device, driving assistance method, and program

Abstract

To provide a driving support device, a driving support method, and a program capable of appropriately suppressing driving support with a smaller processing load.SOLUTION: A recognition unit configured to recognize obstacles including a first obstacle and a second obstacle existing around the vehicle by using at least one of a camera and a radar mounted on the vehicle; a calculation unit configured to calculate a first margin of time before the first obstacle collides with the vehicle and a second margin of time before the first obstacle collides with the second obstacle; and, A driving support unit configured to execute driving support of the vehicle, wherein the driving support unit excludes the first obstacle from an operation target of the driving support when the second time to collision is shorter than the first time to collision.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] In recent years, efforts have been actively made to provide access to a sustainable transportation system that takes into account people in vulnerable positions among traffic participants. Toward this realization, research and development have focused on research and development to further improve traffic safety and convenience through research and development related to preventive safety technology.

[0003] By the way, in preventive safety technology, when an obstacle is detected around a vehicle, driving support such as decelerating the vehicle to avoid a collision with the obstacle is executed. On the other hand, it is an issue to appropriately suppress excessive operation of the driving support. For example, Patent Document 1 describes a technique for suppressing a collision determination with an oncoming vehicle when there is an obstacle such as a roadblock that inhibits a collision between the host vehicle and the oncoming vehicle that intersects the host vehicle. Patent Document 2 describes a technique for determining that a passerby such as a pedestrian or a bicycle intersecting the host vehicle stops with respect to the host vehicle and suppressing a collision determination with the passerby.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, as described above, the conventional technology determines the type of an obstacle and executes or suppresses driving support related to the obstacle according to the determined type, and there may be a heavy processing load.

[0006] This invention has been made in consideration of these circumstances, and one of its objectives is to provide a driver assistance device, a driver assistance method, and a program that can appropriately suppress driver assistance with a smaller processing load. Ultimately, this contributes to the development of a sustainable transportation system. [Means for solving the problem]

[0007] The driver assistance device, driver assistance method, and program according to this invention employ the following configuration. (1) A driving assistance device according to one aspect of the present invention includes: a recognition unit that recognizes obstacles, including a first obstacle and a second obstacle, that are present around the vehicle using at least one of a camera and a radar mounted on the vehicle; a calculation unit that calculates a first collision margin time until the first obstacle collides with the vehicle and a second collision margin time until the first obstacle collides with the second obstacle; and a driving assistance unit that performs driving assistance for the vehicle according to the recognized obstacles, wherein the driving assistance unit excludes the first obstacle from the target of the driving assistance if the second collision margin time is shorter than the first collision margin time.

[0008] (2): In the embodiment of (1) above, the calculation unit calculates at least one of the first collision margin and the second collision margin based on the future trajectory due to the movement of at least one of the first obstacle and the second obstacle.

[0009] (3) In the embodiment of (1) above, the driving support unit excludes the first obstacle from the driving support operation target when the second collision time is shorter than the first collision time and the overlap amount between the first obstacle and the second obstacle is greater than or equal to a predetermined value.

[0010] (4) In the embodiment of (1) above, the driving support unit excludes the first obstacle from the target of the driving support when the second collision time is shorter than the first collision time and the overlap rate of the first obstacle and the second obstacle is greater than or equal to a predetermined value.

[0011] (5) In the embodiment of (1) above, the driving support unit decelerates the vehicle when the collision margin time between the vehicle and the recognized obstacle falls below a threshold.

[0012] (6) A driving assistance method according to another aspect of the present invention involves a computer using at least one of a camera and radar mounted on the vehicle to recognize obstacles, including a first obstacle and a second obstacle, that are present around the vehicle, calculating a first collision margin time until the first obstacle collides with the vehicle and a second collision margin time until the first obstacle collides with the second obstacle, and performing driving assistance for the vehicle according to the recognized obstacles, wherein the driving assistance unit excludes the first obstacle from the target of the driving assistance if the second collision margin time is shorter than the first collision margin time.

[0013] (7) A program according to another aspect of the present invention causes a computer to recognize obstacles, including a first obstacle and a second obstacle, present around the vehicle using at least one of a camera and radar mounted on the vehicle, calculate a first collision margin time until the first obstacle collides with the vehicle and a second collision margin time until the first obstacle collides with the second obstacle, and perform driving assistance for the vehicle according to the recognized obstacles, and the driving assistance unit excludes the first obstacle from the target of the driving assistance if the second collision margin time is shorter than the first collision margin time. [Effects of the Invention]

[0014] According to (1) to (7), it is possible to provide a driver assistance device, a driver assistance method, and a program that can appropriately suppress driver assistance with a smaller processing load.

Brief Description of Drawings

[0015] [Figure 1] It is a diagram showing an example of the configuration of the driving support device 100 mounted on the host vehicle M. [Figure 2] It is a diagram for explaining the outline of driving support executed by the driving support unit 130. [Figure 3] It is a diagram showing an example of suppression of driving support executed by the driving support unit 130. [Figure 4] It is a diagram showing another example of suppression of driving support executed by the driving support unit 130. [Figure 5] It is a flowchart showing an example of the processing flow executed by the driving support device 100. [Figure 6] It is a flowchart showing another example of the processing flow executed by the driving support device 100.

Embodiments for Carrying Out the Invention

[0016] Hereinafter, embodiments of the driving support device, driving support method, and program of the present invention will be described with reference to the drawings.

[0017] [Configuration] FIG. 1 is a diagram showing an example of the configuration of the driving support device 100 mounted on the host vehicle M. The host vehicle M includes, for example, a camera 10, a radar device 12, a vehicle sensor 14, a driving operator 20, a steering wheel 22, a traveling driving force output device 30, a brake device 32, a steering device 34, and a driving support device 100.

[0018] 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 of a vehicle (hereinafter, the host vehicle M) on which the driving support device 100 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, for example, periodically and repeatedly images the periphery of the host vehicle M. The camera 10 may be a stereo camera. The camera 10 transmits the captured image to the driving support device 100, and the driving support device 100 stores the received image in the storage unit 140 as camera image data 140A.

[0019] The radar device 12 radiates radio waves such as millimeter waves to the periphery of the host 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 of the host vehicle M. The radar device 12 may detect the position and speed of an object by an FM-CW (Frequency Modulated Continuous Wave) method. The radar device 12 transmits the detection result to the driving support device 100, and the driving support device 100 stores the detection result in the storage unit 140 as radar detection data 140B.

[0020] The vehicle sensor 14 includes a vehicle speed sensor that detects the speed of the host 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 direction of the host vehicle M, and the like.

[0021] The driver control elements 20 include, for example, a steering wheel 22, as well as an accelerator pedal, brake pedal, shift lever, and other controls. Sensors are attached to the driver control elements 20 to detect the amount of operation or whether or not an operation is performed, and the detection results are output to the driver assistance device 100, or to some or all of the driving force output device 30, brake device 32, and steering device 34. The controls do not necessarily have to be ring-shaped and may take the form of an irregularly shaped steering wheel, joystick, buttons, etc.

[0022] The driving force output device 30 outputs driving force (torque) to the drive wheels for the vehicle M to move. The driving force output device 30 includes, for example, a combination of an internal combustion engine, an electric motor, and a transmission, and an ECU (Electronic Control Unit) that controls them. The ECU controls the above configuration according to information input from the driver assistance device 100 or information input from the driver control device 20.

[0023] The brake system 32 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 a brake ECU. The brake ECU controls the electric motor according to information input from the driver assistance device 100 or from the driver control unit 20, so that brake torque corresponding to the braking operation is output to each wheel. The brake system 32 may also include a backup mechanism that transmits hydraulic pressure generated by the operation of the brake pedal included in the driver control unit 20 to the cylinder via a master cylinder. The brake system 32 is not limited to the configuration described above, and may also be an electronically controlled hydraulic brake system that controls an actuator according to information input from the driver assistance device 100 to transmit hydraulic pressure from the master cylinder to the cylinder.

[0024] The steering device 34 includes, for example, a steering ECU and an electric motor. The electric motor, for example, applies force to a rack and pinion mechanism to change the direction of the steering wheels. The steering ECU drives the electric motor to change the direction of the steering wheels according to information input from the driver assistance device 100 or from the driver control device 20.

[0025] The driver assistance device 100 includes, for example, a recognition unit 110, a calculation unit 120, a driver assistance unit 130, and a storage unit 140. The recognition unit 110, the calculation unit 120, and the driver assistance unit 130 are realized, for example, by a hardware processor such as a CPU (Central Processing Unit) executing a program (software). Some or all of these components may be realized by hardware (including circuitry) such as an LSI (Large Scale Integration), ASIC (Application Specific Integrated Circuit), FPGA (Field-Programmable Gate Array), GPU (Graphics Processing Unit), or SOC (System On Chip), or by the cooperation of software and hardware. The program may be stored in advance in a storage device such as an HDD (Hard Disk Drive) or flash memory (a storage device with a non-transient storage medium), or it may be stored in a removable storage medium such as a DVD or CD-ROM (a non-transient storage medium) and installed when the storage medium is mounted on a drive device. The storage unit 140 is, for example, an HDD, flash memory, RAM (Random Access Memory), etc. The storage unit 140 stores, for example, camera image data 140A and radar detection data 140B.

[0026] The recognition unit 110 performs sensor fusion processing on the detection results obtained from some or all of the camera image data 140A and radar detection data 140B to recognize the position, type, speed, etc., of an object. For example, the recognition unit 110 recognizes pedestrians, other vehicles, road structures (road markings, walls, etc.) that are captured in the camera image by applying image processing to the camera image data 140A. In addition, the recognition unit 110 recognizes pedestrians, other vehicles, road structures (walls, etc.) that are present around the vehicle M based on the radar detection data 140B.

[0027] The calculation unit 120 determines, based on the recognition result from the recognition unit 110, whether or not there are obstacles such as pedestrians or other vehicles around the vehicle M. If it is determined that there are obstacles, it calculates the time to collision (TTC) which is the time until the vehicle M collides with the object, based on the information obtained from the recognition unit 110 and the vehicle sensor 14 (for example, the relative distance to the object and the relative velocity). For example, in the case of Figure 2 described later, the calculation unit 120 calculates TTC = d1 / v based on the distance d1 between the vehicle M and the other vehicle M1 and the relative velocity v of the vehicle M with respect to the other vehicle M1.

[0028] The calculation unit 120 further calculates the TTC between multiple obstacles if the recognition unit 110 recognizes multiple obstacles. For example, if the recognition unit 110 recognizes a first obstacle and a second obstacle, the calculation unit 120 calculates the TTC until the first obstacle collides with the vehicle M, the TTC until the second obstacle collides with the vehicle M, and the TTC until the first obstacle collides with the second obstacle. Hereinafter, the TTC until the first obstacle collides with the vehicle M will be referred to as "first collision buffer time TTC1," and the TTC until the first obstacle collides with the second obstacle will be referred to as "second collision buffer time TTC2."

[0029] The driver assistance unit 130 performs driver assistance for the vehicle M in accordance with the obstacles recognized by the recognition unit 110. Figure 2 is a diagram illustrating the overview of the driver assistance performed by the driver assistance unit 130. In Figure 2, the code CL represents a road lane marking recognized based on camera image data 140A, and the code M1 represents another vehicle.

[0030] The driver support unit 130 provides driving support for the vehicle M based on the recognition results from the recognition unit 110. In this embodiment, "driving support" refers to the Collision Mitigation Brake System (CMBS), which automatically operates the brake device 32 to avoid a collision with an obstacle in the surrounding area or to reduce the collision speed. More specifically, when the calculation unit 120 calculates the time to collision (TTC) of the vehicle M until it collides with an obstacle, the driver support unit 130 determines whether the calculated TTC is below a threshold. If the calculated TTC is below the threshold, the driver support unit 130 activates the CMBS for the vehicle M.

[0031] [Restriction of driver assistance] Thus, the driver assistance unit 130 activates the CMBS on the vehicle M when the TTC calculated by the calculation unit 120 falls below a threshold. However, for example, in an environment where there is an obstacle such as a wall to the side of the vehicle M, if an oncoming vehicle or an overtaking vehicle is detected, the radar device 12 may detect the ghost of the oncoming vehicle or overtaking vehicle as an obstacle via multipath, and the CMBS may malfunction in response to the detected ghost. As a result, in the conventional technology, the CMBS may be activated excessively even when there is no actual need to activate it.

[0032] Given the circumstances described above, the driver assistance unit 130 excludes the first obstacle from the CMBS activation target if the recognition unit 110 recognizes the first obstacle and the second obstacle, and the second collision timeout (TTC2) is shorter than the first collision timeout (TTC1). This is because the first obstacle is expected to collide with the second obstacle earlier than the vehicle M, and therefore there is no need to include the first obstacle in the CMBS activation target. The suppression of driver assistance performed by the driver assistance unit 130 will be explained in more detail below.

[0033] Figure 3 shows an example of driver assistance suppression performed by the driver assistance unit 130. In Figure 3, code M1 represents another vehicle as a ghost recognized by the recognition unit 110, and code M2 ​​represents the actual other vehicle that triggered the other vehicle M2 as a ghost. When the recognition unit 110 recognizes other vehicles M1 and M2, the calculation unit 120 calculates TTC1 until other vehicle M1 collides with the own vehicle M, TTC2 until other vehicle M1 collides with other vehicle M2, and TTC until other vehicle M2 collides with the own vehicle M.

[0034] At this time, the calculation unit 120 predicts the future trajectories of other vehicles M1 and M2 based on their positions and speeds at the time of recognition, and calculates TTC1 and TTC2 based on the predicted future trajectories. For example, in the case of Figure 3, the calculation unit 120 predicts that other vehicle M1 will collide with the own vehicle M at point P1, while other vehicle M1 will collide with other vehicle M2 at point P2, and calculates TTC1 and TTC2.

[0035] The driver support unit 130 compares TTC1 and TTC2, and if TTC2 is shorter than TTC1, it excludes the other vehicle M1 from the CMBS operation target. In the case of Figure 3, since TTC2 is shorter than TTC1, the driver support unit 130 excludes the other vehicle M1 from the CMBS operation target. In Figure 3, as an example, the case in which the recognition unit 110 detects two obstacles around the vehicle M is described, but if the recognition unit 110 detects three or more obstacles around the vehicle M, the calculation unit 120 may calculate TTC, TTC1, and TTC2 for each combination of these three or more obstacles, or it may calculate TTC, TTC1, and TTC2 only for a predetermined number of obstacles (for example, obstacles within a predetermined distance from the vehicle M) among the three or more obstacles.

[0036] Figure 4 shows another example of driver assistance suppression performed by the driver assistance unit 130. In Figure 3, the driver assistance unit 130 unconditionally determines whether or not to activate CMBS for two obstacles recognized by the recognition unit 110, but the driver assistance unit 130 may further consider the overlap rate (degree of overlap) of the obstacles. For example, as shown in Figure 4, the driver assistance unit 130 derives the overlap amount β as the overlap amount (distance in the vehicle width direction in the example of Figure 4) between the area where the width of another vehicle M1 is extended in the direction of travel and the other vehicle M2. The driver assistance unit 130 derives the overlap rate [%] as l = ((β / α) × 100), which is obtained by dividing the overlap amount β by the vehicle width α and multiplying the result by 100.

[0037] The driver assistance unit 130 may exclude other vehicle M1 from the CMBS activation target if TTC2 is shorter than TTC1 and the overlap amount β is greater than or equal to a predetermined value, or if TTC2 is shorter than TTC1 and the overlap ratio l is greater than or equal to a predetermined value. In other words, if the overlap amount β or overlap ratio l is greater than or equal to a predetermined value, it is confirmed that other vehicle M1 has a higher probability of colliding with other vehicle M2, so by further considering the overlap ratio of obstacles, it is possible to more accurately limit the obstacles that should be excluded from the CMBS activation target.

[0038] Furthermore, if the driver support unit 130 determines that the lap amount β or lap ratio l is equal to or greater than a predetermined value, it may maintain that determination for a certain period of time. In other words, even if the lap amount β or lap ratio l falls below a predetermined value within a certain period of time, the driver support unit 130 may exclude the other vehicle M1 from the scope of operation of the CMBS. This makes it possible to suppress the occurrence of hunting associated with the lap amount β or lap ratio l being near a predetermined value.

[0039] [Control flow] Next, the flow of processing performed by the driver assistance device 100 will be described with reference to Figures 5 and 6. Figure 5 is a flowchart showing an example of the flow of processing performed by the driver assistance device 100. The processing shown in the flowchart in Figure 5 is repeatedly performed in a predetermined control cycle while the vehicle M is in motion.

[0040] First, the recognition unit 110 recognizes the first and second obstacles present around the vehicle M (step S100). Next, the calculation unit 120 calculates the TTC1 until the first obstacle collides with the vehicle M, and the TTC2 until the first obstacle collides with the second obstacle (step S102). Next, the driving support unit 130 compares TTC1 and TTC2 to determine whether TTC2 is shorter than TTC1 (step S104).

[0041] If TTC2 is determined to be shorter than TTC1, the driver support unit 130 excludes the first obstacle from the CMBS activation target (step S106). On the other hand, if TTC2 is determined to be greater than or equal to TTC1, the driver support unit 130 sets the first obstacle as a target for CMBS activation (step S108). This completes the processing of this flowchart.

[0042] Figure 6 is a flowchart showing an example of the processing flow performed by the driver assistance device 100. Similar to Figure 5, the processing shown in the flowchart in Figure 6 is repeatedly executed in a predetermined control cycle while the vehicle M is in motion.

[0043] First, the recognition unit 110 recognizes the first and second obstacles present around the vehicle M (step S200). Next, the calculation unit 120 calculates the TTC1 until the first obstacle collides with the vehicle M, and the TTC2 until the first obstacle collides with the second obstacle (step S202). Next, the driving support unit 130 compares TTC1 and TTC2 to determine whether TTC2 is shorter than TTC1 (step S204).

[0044] If TTC2 is determined to be greater than or equal to TTC1, the driver support unit 130 sets the first obstacle as a target for CMBS activation (step S206). On the other hand, if TTC2 is determined to be greater than or equal to TTC1, the driver support unit 130 then determines whether the overlap amount between the first obstacle and the second obstacle is greater than or equal to a predetermined value (step S208). If the overlap amount between the first obstacle and the second obstacle is determined to be less than the predetermined value, the driver support unit 130 sets the first obstacle as a target for CMBS activation (step S206). On the other hand, if the overlap amount between the first obstacle and the second obstacle is determined to be greater than or equal to a predetermined value, the driver support unit 130 excludes the first obstacle from being a target for CMBS activation (step S210). This completes the processing of this flowchart.

[0045] In the flowchart shown in Figure 6, the determination in step S208 is performed after the determination in step S204. However, the present invention is not limited to such a configuration, and the determinations in step S204 and step S208 may be performed in reverse order or simultaneously. Furthermore, in step S208, it is determined whether the amount of overlap is greater than or equal to a predetermined value. Alternatively, it may be determined whether the overlap rate is greater than or equal to a predetermined value.

[0046] As described above, according to this embodiment, at least one of the camera and radar mounted on the vehicle is used to recognize obstacles, including a first obstacle and a second obstacle, that are present around the vehicle. A first collision margin time is calculated, which is the time until the first obstacle collides with the vehicle, and a second collision margin time is calculated, which is the time until the first obstacle collides with the second obstacle. If the second collision margin time is shorter than the first collision margin time, the first obstacle is excluded from the target of the driver assistance system. This makes it possible to appropriately suppress driver assistance with a smaller processing load. In turn, this can contribute to the development of a sustainable transportation system.

[0047] The embodiments described above can be expressed as follows. A storage medium that stores computer-readable instructions, A processor connected to the storage medium, The processor executes the computer-readable instructions to: Using at least one of the cameras and radar mounted on the vehicle, obstacles including a first obstacle and a second obstacle present in the vicinity of the vehicle are recognized. The first collision margin time until the first obstacle collides with the vehicle and the second collision margin time until the first obstacle collides with the second obstacle are calculated. In response to the recognized obstacle, the vehicle's driving assistance is performed. The driver assistance unit excludes the first obstacle from the scope of the driver assistance if the second collision margin is shorter than the first collision margin. A driver assistance system configured in such a way.

[0048] Although embodiments for carrying out the present invention have been described above using examples, the present invention is not limited in any way to these embodiments, and various modifications and substitutions can be made without departing from the spirit of the present invention. [Explanation of Symbols]

[0049] 10 Cameras 12 Radar equipment 14 Vehicle Sensors 20. Operating controls 22 Steering Wheel 30. Driving force output device 32 Brake system 34. Steering system 100 Driving support devices 110 Recognition part 120 Calculation Unit 130 Driver Support Department 140 Storage section 140A Camera Image Data 140B Radar Detection Data

Claims

1. A recognition unit that uses at least one of a camera and radar mounted on the vehicle to recognize obstacles, including a first obstacle and a second obstacle, that are present around the vehicle, A calculation unit that calculates a first collision margin time until the first obstacle collides with the vehicle, and a second collision margin time until the first obstacle collides with the second obstacle, The system includes a driver assistance unit that performs driver assistance for the vehicle in accordance with the recognized obstacle, The driver assistance unit excludes the first obstacle from the scope of the driver assistance if the second collision margin is shorter than the first collision margin. Driving assistance system.

2. The calculation unit calculates at least one of the first collision margin and the second collision margin based on the future trajectory caused by the movement of at least one of the first obstacle and the second obstacle. The driving support device according to claim 1.

3. The driving support unit excludes the first obstacle from the driving support operation target if the second collision margin time is shorter than the first collision margin time and the overlap amount between the first obstacle and the second obstacle is greater than or equal to a predetermined value. The driving support device according to claim 1.

4. The driving support unit excludes the first obstacle from the driving support operation target if the second collision margin time is shorter than the first collision margin time and the overlap rate between the first obstacle and the second obstacle is greater than or equal to a predetermined value. The driving support device according to claim 1.

5. The aforementioned driving support unit decelerates the vehicle when the collision margin time between the vehicle and the recognized obstacle falls below a threshold. The driving support device according to claim 1.

6. Computers Using at least one of the cameras and radar mounted on the vehicle, obstacles including a first obstacle and a second obstacle present in the vicinity of the vehicle are recognized. The first collision margin time until the first obstacle collides with the vehicle and the second collision margin time until the first obstacle collides with the second obstacle are calculated. In response to the recognized obstacle, the vehicle's driving assistance is performed. If the second collision margin is shorter than the first collision margin, the first obstacle is excluded from the operation of the driving assistance system. Driving assistance methods.

7. On the computer, Using at least one of the cameras and radar mounted on the vehicle, obstacles including a first obstacle and a second obstacle present in the vicinity of the vehicle are recognized. The system calculates a first collision margin time until the first obstacle collides with the vehicle, and a second collision margin time until the first obstacle collides with the second obstacle. Depending on the recognized obstacle, the vehicle's driving assistance is performed. If the second collision margin time is shorter than the first collision margin time, the first obstacle is excluded from the operation target of the driving assistance. program.

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