Driving assistance device, driving assistance system, and driving assistance method

Abstract

To provide a technology that can provide driving assistance even in locations where generated map information cannot be used. [Solution] The driving assistance device includes a map generation unit 114 that generates map information including the coordinate position of the road using the coordinate position of the first vehicle 10 and surrounding information indicating landmarks located around the first vehicle detected by a surrounding sensor 120 mounted on the first vehicle, a position information acquisition unit 115 that acquires the planned travel position, which is the coordinate position of the planned travel position of the first vehicle, and a control unit 116 that performs driving assistance control of the first vehicle traveling toward the planned travel position using generated map information, which is map information generated by the map generation unit, and when the generated map information including the planned travel position is not available, a control unit that performs driving assistance control using external map information, which is map information including the planned travel position acquired from outside the first vehicle.

Description

[Technical Field]

[0001] The present disclosure relates to a driving assistance device, a driving assistance system, and a driving assistance method. [Background technology]

[0002] A driving assistance device is known that performs automated driving using highly accurate map information. Patent Document 1 describes a technique for switching to manual driving for portions of a planned route where highly accurate map information does not exist. Patent Document 2 describes a technique for switching from automated driving using a highly accurate first map to automated driving using a second map with lower accuracy than the first map. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6358156 [Patent Document 2] Japanese Patent Publication No. 2022-105410 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a demand for driving assistance using map information generated based on information detected by sensors mounted on vehicles. There has been a demand for technology that can provide driving assistance even in locations where generated map information is not available. [Means for solving the problem]

[0005] The present disclosure has been made to solve the above-mentioned problems, and can be realized in the following forms.

[0006] According to one embodiment of the present disclosure, there is provided a driving assistance device (110). The driving assistance device includes: a map generation unit (114) that generates map information including coordinate positions of roads using a coordinate position of a first vehicle (10) and surrounding information indicating targets located around the first vehicle detected by a surrounding sensor (120) mounted on the first vehicle; a position information acquisition unit (115) that acquires a planned travel position that is a coordinate position of a planned travel position of the first vehicle; and a control unit (116) that performs driving assistance control of the first vehicle traveling toward the planned travel position using generated map information that is map information generated by the map generation unit, and a control unit that performs the driving assistance control using external map information that is map information including the planned travel position acquired from outside the first vehicle when the generated map information including the planned travel position is unavailable.

[0007] According to the driving assistance device of this aspect, even in a location where the generated map information cannot be used, driving assistance can be performed using external map information acquired from outside the vehicle. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram illustrating a configuration of a driving assistance system. [Figure 2] 10 is a flowchart illustrating an example of a map generation process. [Figure 3] 4 is a flowchart illustrating an example of a driving assistance process. DETAILED DESCRIPTION OF THE INVENTION

[0009] A. First embodiment: As shown in Fig. 1, the driving assistance system 500 includes a first vehicle 10, a second vehicle 20, and a driving assistance device 110. In this embodiment, the driving assistance device 110 is mounted on the first vehicle 10. The driving assistance device 110 assists in driving the first vehicle 10. The second vehicle 20 is a vehicle located in the vicinity of the first vehicle 10.

[0010] The first vehicle 10 of this embodiment is equipped with an autonomous driving system 100. In this embodiment, the autonomous driving system 100 performs autonomous driving of the first vehicle 10 as driving assistance. In this embodiment, the autonomous driving system 100 is equipped with a driving assistance device 110, a surroundings sensor 120, a vehicle position sensor 130, a map information storage unit 140, a driving control unit 210, a driving force control ECU (Electronic Control Unit) 220, a braking force control ECU 230, and a steering control ECU 240. The driving assistance device 110, the driving force control ECU 220, the braking force control ECU 230, and the steering control ECU 240 are connected via an in-vehicle network 250. Note that the first vehicle 10 is not limited to being driven autonomously, and may be driven manually by a driver.

[0011] The periphery sensor 120 is a sensor that can detect targets located around the first vehicle 10. The periphery sensor 120 includes a camera 121 and a ranging sensor 122. The camera 121 captures an image of the periphery of the first vehicle 10. The ranging sensor 122 measures the distance to an object around the first vehicle 10. Examples of the ranging sensor 122 include Lidar (Light Detection and Ranging) and millimeter-wave radar that use reflected waves. In this embodiment, the ranging sensor 122 identifies an object around the first vehicle 10 and measures the distance to the object.

[0012] The vehicle position sensor 130 detects the current coordinate position of the first vehicle 10. The vehicle position sensor 130 may be, for example, a Global Navigation Satellite System(s) (GNSS) such as a Global Positioning System (GPS).

[0013] The map information storage unit 140 stores map information of a versatile SD map (Standard Map) and generated map information, which is map information generated by the driving assistance device 110. "Map information" is, for example, information indicating the position of each feature and the position of roads. In this embodiment, the SD map is two-dimensional information including latitude and longitude information, and the generated map information is three-dimensional information including latitude and longitude information. The map information of the SD map is simplified map information, is less accurate than the map information generated by the driving assistance device 110, and does not include detailed road information.

[0014] The driving assistance device 110 is a device that controls the traveling of the first vehicle 10 and performs driving assistance. The driving assistance device 110 includes a storage unit 111, a communication unit 112, and a CPU 113. The CPU 113 executes a program pre-installed in the storage unit 111 to realize the functions of a map generation unit 114, a position information acquisition unit 115, and a control unit 116. However, some or all of the functions of these units may be realized by a hardware circuit.

[0015] The communication unit 112 performs vehicle-to-vehicle communication with the second vehicle 20. By performing vehicle-to-vehicle communication, the first vehicle 10 can acquire various information from the second vehicle 20. The communication unit 112 may perform at least one of wireless communication with an Intelligent Transport System, vehicle-to-vehicle communication with the second vehicle 20, and road-to-vehicle communication with a roadside radio or the like installed on road facilities.

[0016] The map generation unit 114 generates map information usable for driving assistance control by the driving assistance device 110 (described later) using the coordinate position of the first vehicle 10 acquired from the vehicle position sensor 130 and surrounding information acquired from the surrounding sensor 120. The map information usable for driving assistance control is map information with higher accuracy than an SD map, and includes, for example, the positions of white lines and signs, road width, the number of lanes, the positions of intersections, and the angles of intersecting roads. The map generation unit 114 generates map information including, for example, the coordinate positions of roads. More specifically, the map generation unit 114 determines the coordinate positions of targets located in the vicinity of the first vehicle 10 based on the coordinate position of the first vehicle 10 and the surrounding information, and generates generated map information by associating the coordinate positions of the targets with each of the targets in the map information stored in the map information storage unit 140.

[0017] For example, at a location for which generated map information has never been generated, the map generation unit 114 associates the determined coordinate position with each landmark in the map information of the SD map. More specifically, the map generation unit 114 associates the coordinate positions of lane boundaries of a road with information indicating the road in the SD map. Furthermore, at a location for which map information has already been generated, the map generation unit 114 associates the determined coordinate position with each landmark in the generated map information.

[0018] The position information acquisition unit 115 acquires a planned travel position, which is a coordinate position of a planned travel of the first vehicle 10. The position information acquisition unit 115 acquires the planned travel position using the coordinate position of the first vehicle 10 acquired from the vehicle position sensor 130 and the traveling direction of the first vehicle 10. In addition, for example, when the driver sets a destination, the position information acquisition unit 115 may acquire the planned travel position from information indicating a route from the current location to the destination, which is generated by the driving assistance device 110 or another device.

[0019] The control unit 116 performs driving assistance control of the first vehicle 10 traveling toward the planned travel position, using the generated map information generated by the map generation unit 114. In this embodiment, the control unit 116 performs automatic driving to cause the first vehicle 10 to travel to the planned travel position.

[0020] Furthermore, when generated map information including the planned travel position is unavailable, the control unit 116 performs driving assistance control using external map information, which is map information including the planned travel position that is acquired from outside the first vehicle 10. The control unit 116 acquires, for example, external map information generated by the second vehicle 20 from the second vehicle 20. Similar to the first vehicle 10, the second vehicle 20 generates external map information using the coordinate position of the second vehicle 20 and surrounding information detected by a surrounding sensor 120 mounted on the second vehicle 20.

[0021] The driving control unit 210 is composed of a microcomputer configured with a central processing unit (CPU), RAM, and ROM, and realizes an automatic driving function by having the microcomputer execute a pre-installed program. The driving control unit 210 realizes the automatic driving function of traveling to a planned travel position by controlling the driving force control ECU 220, braking force control ECU 230, and steering control ECU 240 under the control of the control unit 116. The driving control unit 210 controls, for example, the driving force control ECU 220 and braking force control ECU 230, and automatically changes lanes using the steering control ECU 240.

[0022] The driving force control ECU 220 is an electronic control device that controls a power source, such as an engine, that generates driving force for the first vehicle 10. When the driver drives manually, the driving force control ECU 220 controls the power source, such as the engine or electric motor, according to the amount of accelerator pedal operation. When autonomous driving is performed, the driving force control ECU 220 controls the power source according to the required driving force calculated by the driving control unit 210.

[0023] The braking force control ECU 230 is an electronic control device that controls a brake actuator that generates a braking force for the first vehicle 10. When the driver drives manually, the braking force control ECU 230 controls the brake actuator in accordance with the amount of operation of the brake pedal. When automatic driving is performed, the braking force control ECU 230 controls the brake actuator in accordance with the required braking force calculated by the driving control unit 210.

[0024] The steering control ECU 240 is an electronic control device that controls a motor that generates steering torque for the first vehicle 10. When the driver drives manually, the steering control ECU 240 controls the motor in accordance with the operation of the steering wheel to generate an assist torque for the steering operation. This allows the driver to operate the steering wheel with a small amount of force, and realizes steering of the first vehicle 10. When autonomous driving is performed, the steering control ECU 240 performs steering by controlling the motor in accordance with the required steering angle calculated by the driving control unit 210.

[0025] The map generation process shown in Fig. 2 is a process in which the map generation unit 114 generates map information. This process is repeatedly executed by the driving assistance device 110 while the first vehicle 10 is traveling, for example, every 100 ms. This process is also referred to as a "map generation step." Below, an example will be described in which map information is generated for a location where no generated map information has ever been generated.

[0026] In step S100, the map generation unit 114 acquires the current coordinate position of the first vehicle 10 from the vehicle position sensor .

[0027] In step S110, the map generation unit 114 acquires, from the map information storage unit 140, map information of the SD map that includes the coordinate position acquired in step S100.

[0028] In step S120, the map generation unit 114 acquires surrounding information from the surrounding sensor 120. Note that steps S100 to S120 are not limited to this order, and can be performed in any order or in parallel, as long as the processing of step S110 is performed after the processing of step S100.

[0029] In step S130, the map generation unit 114 determines coordinate positions indicating the latitude and longitude of targets located around the first vehicle 10 based on the coordinate position of the first vehicle 10 acquired in step S100 and the surrounding information acquired in step S120, and generates map information by correlating the coordinate positions with each target in the map information of the SD map acquired in step S110. The map information storage unit 140 stores the generated map information generated by the map generation unit 114.

[0030] 3 is a process in which the driving assistance device 110 performs driving assistance for the first vehicle 10. This process is a process that is repeatedly executed by the driving assistance device 110 while the first vehicle 10 is traveling by autonomous driving, and is a process that is repeatedly executed every 100 ms, for example.

[0031] In step S200, the position information acquisition unit 115 executes a "position information acquisition step" of acquiring the planned traveling position of the first vehicle 10. In this embodiment, the position information acquisition unit 115 determines the planned traveling position of the first vehicle 10 based on the current coordinate position of the first vehicle 10 and the traveling direction of the first vehicle 10 acquired from the map generation unit 114.

[0032] In step S210, the control unit 116 determines whether or not the generated map information including the planned travel position acquired in step S200 is available. If the generated map information is available, i.e., if map information available for driving assist control has been generated, the control unit 116 proceeds to the process of step S245. On the other hand, if the generated map information is not available, i.e., if map information available for driving assist control has not been generated, the control unit 116 proceeds to the process of step S220.

[0033] In step S220, the driving assistance device 110 acquires, from the second vehicle 20, external map information including the planned travel position acquired in step S200.

[0034] In step S230, the driving assistance device 110 determines whether the external map information acquired in step S220 is similar to the generated map. More specifically, the driving assistance device 110 determines whether the similarity between a predetermined element of the generated map information and an element of the external map information is equal to or greater than a predetermined threshold.

[0035] In this embodiment, the similarity is a value indicating the degree of similarity between driving behaviors. For example, if a vehicle tends to drive more to the right of the center of the lane, the coordinates of the white line corresponding to the left boundary of the lane in the width direction tend to be more variable than the coordinates of the white line corresponding to the right boundary of the lane in the width direction. Therefore, the driving assistance device 110 determines the degree of similarity between the tendency of variation in the coordinates of the white lines in the generated map information and the tendency of variation in the coordinates of the white lines in the external map information as the degree of similarity between the driving behaviors.

[0036] If the external map information is similar, that is, if the similarity is equal to or greater than the threshold, the driving assistance device 110 proceeds to the process of step S240. On the other hand, if the external map information is not similar, that is, if the similarity is less than the threshold, the driving assistance device 110 ends the driving assistance process.

[0037] In step S240, the driving assistance device 110 adopts the external map information that is similar to the generated map information as the map to be used for driving assistance.

[0038] In step S245, the driving assistance device 110 acquires, from the map information storage unit 140, generated map information including the planned travel position acquired in step S200.

[0039] In step S250, the control unit 116 performs driving assistance control of the first vehicle 10 using the generated map information acquired in step S245 or the external map information adopted in step S240. More specifically, the control unit 116 uses the map information to determine the control content of the first vehicle 10 and instructs the driving control unit 210 to perform the determined driving assistance control. For example, the driving assistance device 110 determines the driving speed according to the speed limit of the road on the planned driving route included in the map information. The process combining steps S210 to S250 is also referred to as the "driving assistance control process."

[0040] According to the driving assistance device 110 of the present embodiment described above, driving assistance is performed using generated map information, so driving assistance can be performed even if highly accurate map information is not available in advance. Furthermore, even in locations where the generated map information cannot be used, driving assistance can be performed using external map information acquired from outside the first vehicle 10.

[0041] Furthermore, because driving assistance is performed using external map information whose similarity is equal to or greater than a threshold, there is a high probability that driving assistance control using the generated map information and driving assistance control using the external map information will be similar, and there is a high probability that the sense of incongruity felt when switching between driving assistance using the generated map information and driving assistance using the external map information can be reduced.

[0042] The similarity is the degree to which the driving mode of the first vehicle 10 is similar to the driving mode of the second vehicle 20. Therefore, driving assistance can be performed using external map information generated by the second vehicle 20, which has a similar driving mode, and therefore there is a high probability that the sense of discomfort felt when switching between manual driving or driving with driving assistance using generated map information, and driving with driving assistance using external map information can be reduced.

[0043] B. Other Embodiments: (B1) In the above-described embodiment, the driving assistance device 110 is mounted on the first vehicle 10. However, the driving assistance device 110 may be mounted on, for example, a server provided outside the first vehicle 10 or a transportation infrastructure.

[0044] (B2) In the above-described embodiment, the driving assistance system 500 does not need to include the second vehicle 20. In this case, the driving assistance device 110 acquires external map information from road facilities such as traffic lights and electronic bulletin boards, or communication devices installed in commercial facilities or public facilities.

[0045] (B3) In the above-described embodiment, the driving assistance system 500 may include a plurality of second vehicles 20. In this case, the driving assistance device 110 adopts map information to be used for driving assistance from the external map information acquired from each second vehicle 20. The driving assistance device 110 can adopt, for example, the external map information with the highest accuracy or the external map information with the highest similarity from among the plurality of pieces of external map information acquired.

[0046] (B4) In the driving assistance process in the above-described embodiment, the driving assistance device 110 employs external map information whose similarity is equal to or greater than a threshold value for driving assistance control. This is not a limitation, and the driving assistance device 110 may omit step S230 (see FIG. 3). In this case, in step S240, the driving assistance device 110 employs the external map information acquired in step S220 for driving assistance control regardless of the similarity. Furthermore, the driving assistance device 110 may employ external map information whose accuracy is equal to or greater than a predetermined threshold value for driving assistance control.

[0047] (B5) In the above-described embodiment, the similarity is a value indicating the degree of similarity between the driving behaviors, and the degree of similarity between the tendency of variation in the coordinates of white lines in the generated map information and the tendency of variation in the coordinates of white lines in the external map information is taken as the similarity of the driving behaviors. However, the similarity is not limited to this. The similarity may simply be a value indicating the similarity of the tendency of variation in the coordinates of white lines, regardless of the similarity of the driving behaviors, or a value indicating the similarity of the tendency of deviation in the coordinates of each target in the yaw axis direction. Furthermore, the similarity may be the degree of similarity in the accuracy of the map information. For example, the accuracy of the map information is higher when it includes information on speed limits or no-entry signs that can be recognized from signs, etc., than when it does not include such information.

[0048] (B6) In the above-described embodiment, the driving assistance device 110 may acquire information about the driving behavior together with the external map information. In this case, the driving assistance device 110 can calculate the similarity using the acquired information about the driving behavior.

[0049] (B7) In the above-described embodiment, the driving assistance process is a process that is repeatedly executed while the first vehicle 10 is traveling by autonomous driving. However, the driving assistance process may be executed at the start of autonomous driving that causes the first vehicle 10 to travel from its current location to its destination. In this case, in step S200 (see FIG. 3 ), the position information acquisition unit 115 acquires, as planned travel positions, coordinate positions of the planned travel route to the destination. Furthermore, the control unit 116 acquires external map information that includes planned travel positions for which generated map information is not available on the planned travel route, and determines the external map information to be used for driving assistance control for each planned travel position.

[0050] The present disclosure is not limited to the above-described embodiments and can be realized in various configurations without departing from the spirit thereof. For example, the technical features in the embodiments corresponding to the technical features in each aspect described in the Summary of the Invention section can be appropriately replaced or combined to solve the above-described problems or achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted.

[0051] The driving assistance device 110 and the method described herein may be implemented by a special-purpose computer configured by configuring a processor and memory programmed to perform one or more functions embodied in a computer program. Alternatively, the control unit and the method described herein may be implemented by a special-purpose computer configured by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the restriction unit and the method described herein may be implemented by one or more special-purpose computers configured by combining a processor and memory programmed to perform one or more functions with a processor configured with one or more hardware logic circuits. Furthermore, the computer program may be stored in a computer-readable non-transitory tangible storage medium as instructions executed by a computer. [Explanation of symbols]

[0052] 10...first vehicle, 20...second vehicle, 100...autonomous driving system, 110...driving assistance device, 111...memory unit, 112...communication unit, 113...CPU, 114...map generation unit, 115...position information acquisition unit, 116...control unit, 120...surrounding sensor, 121...camera, 122...distance measurement sensor, 130...vehicle position sensor, 140...map information memory unit, 210...driving control unit, 220...driving force control ECU, 230...braking force control ECU, 240...steering control ECU, 250...in-vehicle network, 500...driving assistance system

Claims

1. A driving assistance device, a map generating unit (114) that generates map information including coordinate positions of roads using the coordinate position of a first vehicle (10) and surrounding information indicating targets located around the first vehicle detected by a surrounding sensor (120) mounted on the first vehicle; a position information acquisition unit (115) that acquires a planned travel position, which is a coordinate position of a planned travel position of the first vehicle; a control unit (116) that performs driving assistance control of the first vehicle traveling toward the planned travel position using generated map information, which is map information generated by the map generation unit, and that performs the driving assistance control using external map information, which is map information including the planned travel position, obtained from outside the first vehicle when the generated map information including the planned travel position is unavailable.

2. The driving assistance device according to claim 1, The control unit performs the driving assistance control using the external map information in which a similarity between a predetermined element of the generated map information and the element of the external map information is equal to or greater than a predetermined threshold.

3. The driving assistance device according to claim 2, the external map information is generated by a second vehicle (20) different from the first vehicle, A driving assistance device, wherein the element includes information regarding a driving mode of the first vehicle or the second vehicle.

4. A driving assistance system (500), a first vehicle equipped with a surrounding sensor; a second vehicle located in the vicinity of the first vehicle; a map generating unit that generates map information including coordinate positions of roads using the coordinate position of the first vehicle and surrounding information indicating targets located around the first vehicle detected by the surrounding sensor; a position information acquisition unit that acquires a planned travel position, which is a coordinate position of a planned travel position of the first vehicle; a control unit that performs driving assistance control of the first vehicle traveling toward the planned travel position using generated map information, which is map information generated by the map generation unit, and when the generated map information including the planned travel position is unavailable, performs the driving assistance control using external map information, which is map information including the planned travel position, obtained from the second vehicle.

5. A driving assistance method, a map generating step of generating map information including coordinate positions of roads using a coordinate position of a first vehicle and surrounding information indicating targets located around the first vehicle detected by a surrounding sensor mounted on the first vehicle; a position information acquisition step of acquiring a planned travel position, which is a coordinate position of a planned travel position of the first vehicle; a driving assistance control step of, when generated map information is available, which is map information generated in the map generation step and includes the planned travel position, using the generated map information to perform driving assistance control of the first vehicle traveling toward the planned travel position, and, when the generated map information including the planned travel position is unavailable, performing the driving assistance control using external map information, which is map information including the planned travel position and is obtained from outside the first vehicle.

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