Deceleration support device, deceleration support method, and program

Abstract

This effectively improves the accuracy of deceleration support control. [Solution] A deceleration support device that performs deceleration support control to slow down a vehicle when it detects a curved road in front of a moving vehicle, acquires first road shape information including the road shape in front of the vehicle based on the detection result of a location information detection device that detects the vehicle's location information and a map database, and acquires second road shape information including the road shape in front of the vehicle based on the recognition result of a forward recognition sensor mounted on the vehicle that recognizes the area in front of the vehicle, and if the first road shape information and the second road shape information do not match, deceleration support control is performed based on the second road shape information.

Description

Technical Field

[0001] The present disclosure relates to a deceleration assistance device, a deceleration assistance method, and a program.

Background Art

[0002] When the curve information of a road acquired based on the road information of a navigation device does not match the actual curve information of the road calculated from the turning motion parameters representing the vehicle behavior detected by sensors, Patent Document 1 discloses a device that determines that the road information obtained from the navigation device is unreliable and cancels a control command such as deceleration assistance.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] In the device described in Patent Document 1, consistency is determined using the turning motion parameters of the vehicle obtained from the detection results of sensors. Therefore, the consistency determination process cannot be performed unless the vehicle actually reaches a curved road. That is, there is a problem that the determination result cannot be effectively reflected in deceleration assistance or the like that starts before the vehicle reaches a curved road.

[0005] The present disclosure has been made to solve the above problems, and an object thereof is to effectively improve the accuracy of deceleration assistance control.

[0006] The device of the present disclosure is a deceleration assistance device that implements deceleration assistance control to decelerate the vehicle when a curved road is detected in front of the traveling vehicle, Based on the detection results of a location information detection device that detects the location information of the vehicle and a map database, first road shape information including the road shape in front of the vehicle is acquired, and second road shape information including the road shape in front of the vehicle is acquired based on the recognition results of a forward recognition sensor mounted on the vehicle that recognizes the area in front of the vehicle. If the first road shape information and the second road shape information do not match, the deceleration support control is performed based on the second road shape information. Characterized by

[0007] The methods of this disclosure A deceleration support method that performs deceleration support control to slow down a moving vehicle when a curved road is detected in front of the vehicle, Based on the detection results of a location information detection device that detects the location information of the vehicle and a map database, first road shape information including the road shape in front of the vehicle is acquired, and second road shape information including the road shape in front of the vehicle is acquired based on the recognition results of a forward recognition sensor mounted on the vehicle that recognizes the area in front of the vehicle. If the first road shape information and the second road shape information do not match, the deceleration support control is performed based on the second road shape information. It is characterized by the following:

[0008] The program disclosed herein is When a curved road is detected in front of a moving vehicle, the computer of the deceleration support device that performs deceleration support control to slow down the vehicle, The process includes acquiring first road shape information, including the road shape in front of the vehicle, based on the detection result of a location information detection device that detects the location information of the vehicle and a map database, and acquiring second road shape information, including the road shape in front of the vehicle, based on the recognition result of a forward recognition sensor mounted on the vehicle that recognizes the area in front of the vehicle. If the first road shape information and the second road shape information do not match, the system will perform a process to implement the deceleration support control based on the second road shape information. It is characterized by the following: [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram showing the hardware configuration of the vehicle according to this embodiment. [Figure 2] This is a schematic diagram showing the software configuration of the control device according to this embodiment. [Figure 3] This table explains the process for determining whether or not deceleration support control can be executed according to this embodiment. [Figure 4] This flowchart illustrates the process for determining whether or not deceleration support control can be executed according to this embodiment. [Modes for carrying out the invention]

[0010] The deceleration support device, deceleration support method, and program according to this embodiment will be described below with reference to the drawings.

[0011] [Hardware configuration] Figure 1 is a schematic diagram showing the hardware configuration of vehicle VH according to this embodiment. Hereinafter, vehicle VH may be referred to as "our vehicle" when it is necessary to distinguish it from other vehicles, etc.

[0012] Vehicle VH has an ECU (Electronic Control Unit) 10. The ECU 10 includes a CPU (Central Processing Unit) 11, ROM (Read Only Memory) 12, RAM (Random Access Memory) 13, and an interface device 14, etc. The CPU 11 is a processor that executes various programs stored in the ROM 12. The ROM 12 is a non-volatile memory that stores data necessary for the CPU 11 to execute various programs. The RAM 13 is a volatile memory that provides a work area that is expanded when various programs are executed by the CPU 11. The interface device 14 is a communication device for communicating with external devices.

[0013] The ECU10 is a central device that provides driving assistance for the vehicle (VH). Driving assistance is a concept that includes autonomous driving. In this embodiment, the ECU10 performs Deceleration Assist (DA) control to assist the driver of the vehicle (VH) in deceleration operations. Details of the Deceleration Assist control will be described later. The ECU10 is connected to the drive unit 20, steering unit 21, braking unit 22, internal sensor unit 30, external sensor unit 40, location information acquisition unit 60, map database 70, etc., in a communication manner.

[0014] The drive unit 20 generates a driving force that is transmitted to the drive wheels of the vehicle VH. Examples of the drive unit 20 include an electric motor and an engine. In this embodiment, the vehicle VH may be a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), a fuel cell electric vehicle (FCEV), a battery electric vehicle (BEV), or an engine-powered vehicle. The steering unit 21 applies steering force to the wheels of the vehicle VH. The braking unit 22 applies braking force to the wheels of the vehicle VH.

[0015] The internal sensor device 30 consists of sensors that acquire the driving status of the vehicle VH. The internal sensor device 30 includes a vehicle speed sensor 31, an accelerator sensor 32, a brake sensor 33, a steering angle sensor 34, a yaw rate sensor 35, a lateral acceleration sensor 36, and the like.

[0016] The vehicle speed sensor 31 detects the vehicle speed (vehicle speed) of the vehicle VH. The accelerator sensor 32 detects the amount of accelerator pedal operation by the driver (not shown). The brake sensor 33 detects the amount of brake pedal operation by the driver (not shown). The steering angle sensor 34 detects the rotation angle (steering angle) of the steering wheel or steering shaft (not shown). The yaw rate sensor 35 detects the yaw rate of the vehicle VH. The lateral acceleration sensor 36 detects the lateral acceleration, which is the acceleration of the vehicle VH in the vehicle width direction. The internal sensor device 30 transmits the driving state of the vehicle VH detected by each sensor 31 to 36 to the ECU 10 at a predetermined interval.

[0017] The external sensor device 40 (an example of the front recognition sensor of the present disclosure) is sensors that recognize target information regarding targets around the vehicle VH. The external sensor device 40 includes a radar sensor 41, a camera sensor 42, and the like. Here, examples of the target information include surrounding vehicles, the shape of the road, the white lines on the road, road signs, and the like.

[0018] The radar sensor 41 detects targets existing around the vehicle VH. The radar sensor 41 includes a millimeter-wave radar and / or a lidar. The millimeter-wave radar emits radio waves in the millimeter-wave band and receives the millimeter waves reflected by targets existing within the radiation range. The millimeter-wave radar obtains the relative distance, relative speed, etc. between the vehicle VH and the target based on the phase difference between the transmitted millimeter waves and the received reflected waves, the attenuation level of the reflected waves, the time from transmitting the millimeter waves to receiving the reflected waves, and the like. The lidar sequentially scans pulsed laser light with a shorter wavelength than millimeter waves in a plurality of directions, and receives the reflected light reflected by the target, thereby obtaining the shape of the target detected around the vehicle VH, the relative distance between the vehicle VH and the target, the relative speed, and the like.

[0019] The camera sensor 42 photographs the surroundings of the vehicle VH, and obtains target information around the vehicle VH by processing the photographed image data. As the camera sensor 42, for example, a digital camera having an image pickup device such as a CMOS or a CCD can be used. The target information is information representing the type of the target detected around the vehicle VH, the relative distance between the vehicle VH and the target, the relative speed, and the like. The type of the target may be recognized by machine learning such as pattern matching.

[0020] The external sensor device 40 repeatedly transmits the acquired target information to the ECU 10 every time a predetermined time elapses. Note that the external sensor device 40 does not necessarily have to include both the radar sensor 41 and the camera sensor 42, and may include, for example, only the camera sensor 42.

[0021] The location information detection device 60 detects the current location information of the vehicle VH. For example, the location information detection device 60 can use a GPS (Global Positioning System), GNSS (Global Navigation Satellite System), or other system provided by a navigation system (not shown). The location information detection device 60 transmits the detected current location information of the vehicle VH to the ECU 10 at predetermined intervals.

[0022] The map database 70 is, for example, a database of map information provided by a navigation system, and is stored in a storage device (hard disk, flash memory, etc.) of the vehicle VH. The map information includes, for example, information representing the shape of roads, such as the radius of curvature of curved roads. The map database 70 may also be stored in an external server that can communicate with the vehicle VH. In this case, the vehicle VH can obtain map information from the external server through a communication device (not shown).

[0023] [Software Configuration] Figure 2 is a schematic diagram showing the software configuration of the control device according to this embodiment.

[0024] As shown in Figure 2, the ECU 10 includes functional elements such as a road shape information acquisition unit 100 and a deceleration support control unit 110. Each of these functional elements 100 and 110 is realized when the CPU 11 of the ECU 10 reads a program stored in the ROM 12 into the RAM 13 and executes it. Note that all or part of each of the functional elements 100 and 110 may be installed in another ECU separate from the ECU 10, or in an information processing device of a facility (such as a management center) that can communicate with the vehicle VH.

[0025] The road shape information acquisition unit 100 acquires road shape information (e.g., curvature of curves, distance to curves, etc.) representing the shape of the road ahead of the vehicle VH, based on the current location information of the vehicle VH detected by the location information detection device 60 and the map database 70. Hereinafter, the road shape information acquired based on the map database 70 will be referred to as "first road shape information". The road shape information acquisition unit 100 also acquires road shape information (e.g., curvature of curves, etc.) representing the shape of the road ahead of the vehicle VH, based on the detection results of the external sensor device 40. Hereinafter, the road shape information acquired based on the detection results of the external sensor device 40 will be referred to as "second road shape information". Furthermore, the road shape information acquisition unit 100 acquires road shape information (e.g., curvature of curves, etc.) representing the shape of the road on which the vehicle VH is traveling, based on the turning parameters of the vehicle VH (steering angle, yaw rate, lateral acceleration, etc.) detected by the internal sensor device 30. Hereinafter, the road shape information acquired based on the internal sensor device 30 will be referred to as "third road shape information". The road shape information acquisition unit 100 sequentially transmits the acquired first road shape information, second road shape information, and third road shape information to the deceleration support control unit 100.

[0026] When the deceleration support control unit 110 detects a deceleration target in front of the moving vehicle VH, it performs deceleration support control to assist the driver of vehicle VH in deceleration. Examples of deceleration targets include a curved road in front of the moving vehicle VH, a preceding vehicle traveling in front of the vehicle VH, and a vehicle cutting in from an adjacent lane ahead of the vehicle VH in its own lane. The following describes the deceleration support control when a curved road is detected in front of the vehicle VH as a deceleration target.

[0027] The deceleration support control unit 110 determines whether deceleration is necessary for the vehicle VH to travel on the curved road detected in front of the vehicle VH at its current speed. If the deceleration support control unit 110 determines that deceleration is necessary, it executes deceleration support control to decelerate the vehicle VH at a desired deceleration rate. Specifically, when the deceleration support control unit 110 detects a curved road in front of the vehicle VH based on the road shape information transmitted from the road shape information acquisition unit 100, it calculates the appropriate vehicle speed for the vehicle VH to travel on the curved road (hereinafter referred to as the appropriate vehicle speed) based on the curvature of the curved road, etc. If the current vehicle speed detected by the vehicle speed sensor 31 is faster than the appropriate vehicle speed, the deceleration support control unit 110 determines that deceleration is necessary. If the deceleration support control unit 110 determines that deceleration is necessary, it calculates the required deceleration necessary to decelerate the vehicle VH to the optimal vehicle speed based on the first road shape information, the second road shape information, and the third road shape information, respectively. In the following, the required deceleration calculated based on the first road shape information will be referred to as the "first required deceleration," the required deceleration calculated based on the second road shape information will be referred to as the "second required deceleration," and the required deceleration calculated based on the third road shape information will be referred to as the "third required deceleration."

[0028] The deceleration support control unit 110 calculates the first required deceleration, the second required deceleration, and the third required deceleration, and sets the deceleration with the largest absolute value among them as the target deceleration. Furthermore, once the target deceleration is set, the deceleration support control unit 110 controls the operation of the braking device 21 based on the set target deceleration. This realizes deceleration support control that reduces the vehicle VH to an appropriate speed suitable for driving on curved roads.

[0029] Incidentally, if the deceleration support control uses first road shape information acquired based on the position information detection device 60 and the map database 70, and second road shape information acquired based on the external sensor device 40, the accuracy of the deceleration support control can be improved, thereby enhancing performance. However, due to errors in the current position of the vehicle VH detected by the position information detection device 60, and the effects of road alignment improvements due to construction work, etc., the road shape acquired based on the map database 70 may differ from the road shape that the vehicle VH is actually trying to travel on. In such situations, if deceleration support control is implemented using first road shape information acquired based on the map database 70, the deceleration support may become unnecessary, leading to a decrease in performance.

[0030] Therefore, the deceleration support control unit 110 of this embodiment suppresses the implementation of deceleration support control if, even if the road in front of the vehicle VH recognized based on the first road shape information is a curved road, the road in front of the vehicle VH recognized based on the second road shape information is not a curved road, that is, if the external sensor device 40 recognizes the road in front of the vehicle VH as a straight road.

[0031] Figure 3 is a table illustrating the process for determining whether or not deceleration support control can be executed according to this embodiment. In the table in Figure 3, the vertical items represent the recognition results based on the external sensor device 40, and the horizontal items represent the recognition results based on the location information detection device 60 and the map database 70.

[0032] Figure 3(A) shows the case where the road in front of vehicle VH, as recognized based on the first road shape information obtained from the position information detection device 60 and the map database 70, is a straight road, and the road in front of vehicle VH, as recognized based on the second road shape information obtained from the detection results of the external sensor device 40, is also a straight road. In this case, the deceleration support control unit 110 does not detect a curved road as a target for deceleration, and therefore does not perform deceleration support control.

[0033] Figure 3(D) shows the case where the road in front of vehicle VH, as recognized based on the first road shape information obtained from the position information detection device 60 and the map database 70, is a curved road, and the road in front of vehicle VH, as recognized based on the second road shape information obtained from the detection results of the external sensor device 40, is also a curved road. In this case, the deceleration support control unit 110 performs deceleration support control based on the first road shape information and the second road shape information obtained by the road shape information acquisition unit 100. That is, both the first road shape information and the second road shape information are used for deceleration support control. This makes it possible to effectively improve the accuracy of deceleration support control.

[0034] Figure 3(C) shows the case where the road in front of vehicle VH, as recognized based on the first road shape information obtained from the position information detection device 60 and the map database 70, is a straight road, and the road in front of vehicle VH, as recognized based on the second road shape information obtained from the detection results of the external sensor device 40, is a curved road. In this case, the deceleration support control unit 110 performs deceleration support control using the second road shape information obtained based on the detection results of the external sensor device 40. This makes it possible to start deceleration support control at an earlier timing, even before the curved road in front of vehicle VH is recognized based on the position information detection device 60 and the map database 70.

[0035] Figure 3(B) shows the case where the road in front of vehicle VH, as recognized based on the first road shape information acquired from the position information detection device 60 and the map database 70, is a curved road, and the road in front of vehicle VH, as recognized based on the second road shape information acquired from the detection results of the external sensor device 40, is a straight road. In this case, the deceleration support control unit 110 does not perform deceleration support control. That is, the implementation of deceleration support control based on the first road shape information acquired by the position information detection device 60 and the map database 70 is suppressed. This makes it possible to effectively prevent unnecessary operation of deceleration support control when the road shape recognized from the map database 70 differs from the actual road shape, etc.

[0036] Figure 4 is a flowchart illustrating the process by which the ECU 10 determines whether or not deceleration support control can be performed. The specific details of the deceleration support control itself, such as determining whether or not deceleration is necessary, setting the target deceleration speed, and controlling the operation of the braking device 22, are publicly known, so these explanations are omitted from the flowchart shown in Figure 4. The routine shown in Figure 4 is started, for example, when vehicle VH is moving.

[0037] In step S100, the ECU 10 acquires first road shape information in front of the vehicle VH based on the position information detection device 60 and the map database 70. Then, in step S110, the ECU 10 determines whether the road in front of the vehicle VH is a straight road or not based on the first road shape information. If the road in front of the vehicle VH is determined to be a straight road (Yes), the ECU 10 proceeds to the process in step S120. On the other hand, if the road in front of the vehicle VH is not determined to be a straight road (No), that is, if it is recognized as a curved road, the ECU 10 proceeds to the process in step S200.

[0038] In step S120, the ECU 10 acquires second road shape information in front of the vehicle VH based on the detection results of the external sensor device 40. Then, in step S130, the ECU 10 determines whether the road in front of the vehicle VH is a straight road based on the second road shape information. If the ECU 10 determines in step S130 that the road in front of the vehicle VH is a straight road (Yes), then both the first road shape information and the road in front of the vehicle VH recognized based on the second road shape information are straight roads. In this case, the ECU 10 returns to this routine without performing deceleration support control.

[0039] On the other hand, if step S130 does not determine that the road in front of vehicle VH is a straight road (No), that is, if it is recognized as a curved road, the ECU 10 proceeds to step S140. In step S140, deceleration support control is performed using second road shape information acquired based on the detection results of the external sensor device 40, and then this routine is returned.

[0040] In step S200, the ECU 10 acquires second road shape information in front of the vehicle VH based on the detection results of the external sensor device 40. Then, in step S210, the ECU 10 determines whether the road in front of the vehicle VH is a straight road based on the second road shape information. If the ECU 10 determines in step S210 that the road in front of the vehicle VH is a straight road (Yes), then the road in front of the vehicle VH recognized based on the first road shape information is a curved road, but the road in front of the vehicle VH recognized based on the second road shape information is a straight road. In this case, the ECU 10 returns this routine without performing deceleration support control.

[0041] On the other hand, if step S210 does not determine that the road in front of vehicle VH is a straight road (No), that is, if it is recognized as a curved road, the ECU 10 proceeds to step S220. In step S220, deceleration support control is performed using the first road shape information obtained based on the position information detection device 60 and the map database 70, and the second road shape information obtained based on the detection result of the external sensor device 40, and then this routine is returned.

[0042] Although the deceleration support device, deceleration support method, and program according to this embodiment have been described above, this disclosure is not limited to the above embodiments, and various modifications are possible as long as they do not depart from the purpose of the present invention.

[0043] For example, in the above embodiment, deceleration support control was described as being performed when the vehicle VH is being driven manually by the driver, but the technology of this disclosure can also be applied to deceleration control that slows down the vehicle VH on a curved road while adaptive cruise control (ACC) is being performed. Furthermore, this disclosure can also be applied to autonomous vehicles that perform some or all of the driving operations automatically.

Claims

1. A deceleration support device that performs deceleration support control to slow down a vehicle when it detects a curved road in front of the vehicle while it is in motion, Based on the detection results of a location information detection device that detects the location information of the vehicle and a map database, first road shape information including the road shape in front of the vehicle is acquired, and second road shape information including the road shape in front of the vehicle is acquired based on the recognition results of a forward recognition sensor mounted on the vehicle that recognizes the area in front of the vehicle. If the first road shape information and the second road shape information do not match, the deceleration support control is performed based on the second road shape information. A deceleration support device characterized by the following features.

2. A deceleration support device according to claim 1, If the first road shape information and the second road shape information match, the deceleration support control is performed based on both the first road shape information and the second road shape information. A deceleration support device characterized by the following features.

3. A deceleration support device according to claim 1, Even if the first road shape information indicates that a curved road is recognized in front of the vehicle, if the second road shape information does not indicate that a curved road is recognized in front of the vehicle, the deceleration support control will not be performed. A deceleration support device characterized by the following features.

4. A deceleration support method that performs deceleration support control to slow down a moving vehicle when a curved road is detected in front of the vehicle, Based on the detection results of a location information detection device that detects the location information of the vehicle and a map database, first road shape information including the road shape in front of the vehicle is acquired, and second road shape information including the road shape in front of the vehicle is acquired based on the recognition results of a forward recognition sensor mounted on the vehicle that recognizes the area in front of the vehicle. If the first road shape information and the second road shape information do not match, the deceleration support control is performed based on the second road shape information. A deceleration support method characterized by the following features.

5. When a curved road is detected in front of a moving vehicle, the computer of the deceleration support device that performs deceleration support control to slow down the vehicle, The process includes acquiring first road shape information, including the road shape in front of the vehicle, based on the detection result of a location information detection device that detects the location information of the vehicle and a map database, and acquiring second road shape information, including the road shape in front of the vehicle, based on the recognition result of a forward recognition sensor mounted on the vehicle that recognizes the area in front of the vehicle. If the first road shape information and the second road shape information do not match, the system will perform a process to implement the deceleration support control based on the second road shape information. A program characterized by the following features.

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