JP2024034358A - vehicle - Google Patents

Abstract

[Problem] To suppress narrowing of the expression angle. A vehicle includes a first sensor, a second sensor, and a control device. The first sensor detects the position of a first detection point representing a part of the surface of the object in a two-dimensional coordinate system. The second sensor detects the position of a second detection point representing a part of the surface of the object in a two-dimensional coordinate system. The control device derives the position of the virtual detection point in a two-dimensional coordinate system with the virtual sensor as the origin based on the detection result of the first sensor and the detection result of the second sensor. The control device moves the virtual sensor from the reference position to approach the object based on the detection result of the first sensor and the detection result of the second sensor. [Selection diagram] Figure 5

Description

TECHNICAL FIELD This disclosure relates to vehicles.

The vehicle disclosed in Patent Document 1 includes a plurality of sensors and a control device. The control device obtains new information by combining detection results from multiple sensors. This allows the control device to recognize the external situation.

JP2022-24493A

A vehicle may include a plurality of sensors that detect the position of a detection point in a two-dimensional coordinate system. When obtaining new information by combining the detection results of the sensors, the control device derives the position of the virtual detection point in a two-dimensional coordinate system with the virtual sensor as the origin from the detection results of the plurality of sensors. In this case, due to the difference between the position of the sensor and the position of the virtual sensor, there is a possibility that the expression angle that expresses the object with the virtual sensor as the origin becomes narrower than the expression angle that expresses the object with the sensor as the origin.

A vehicle that solves the above problems includes a first sensor that detects the position in a two-dimensional coordinate system of a first detection point representing a part of the surface of an object, and a second detection point representing a part of the surface of the object. a second sensor that detects a position in a two-dimensional coordinate system of Deriving the position of a virtual detection point in a two-dimensional coordinate system with the sensor as the origin, and approaching the object from the reference position based on the detection result of the first sensor and the detection result of the second sensor. The virtual sensor is moved.

The control device moves the position of the virtual sensor so as to approach the object. When the position of the virtual sensor is kept constant, depending on the positional relationship between the object and the virtual sensor, there is a possibility that the expression angle for expressing the object using the virtual sensor as the origin may become narrower. By moving the position of the virtual sensor so as to approach the object, narrowing of the expression angle can be suppressed.

Regarding the vehicle, the control device may move the virtual sensor on a virtual line segment connecting the first sensor and the second sensor.
Regarding the vehicle, the control device calculates a first average value that is an average value of distances to the plurality of first detection points detected by the first sensor in one cycle, and calculates a first average value that is an average value of distances to the plurality of first detection points detected by the first sensor in one cycle, and A second average value that is an average value of the distances to the plurality of second detection points to be detected is calculated, and the distance from the first sensor to the virtual sensor and the distance from the second sensor to the virtual sensor are calculated. The virtual sensor may be moved such that the ratio matches the ratio between the first average value and the second average value.

According to the present invention, narrowing of the expression angle can be suppressed.

FIG. 1 is a schematic configuration diagram of a vehicle. 2 is a diagram showing the viewing angle and angular resolution of a sensor included in the vehicle of FIG. 1. FIG. 2 is a diagram showing the positions of sensors included in the vehicle of FIG. 1. FIG. 2 is a diagram schematically showing a virtual sensor generated by the control device of FIG. 1. FIG. 2 is a flowchart showing control performed by the control device of FIG. 1. FIG. 6 is a diagram for explaining control when the control device calculates the position of a virtual generation point in the flowchart of FIG. 5. FIG. FIG. 3 is a diagram showing a transition in the position of a virtual sensor as the vehicle moves. FIG. 3 is a diagram for explaining expression angles.

An embodiment of a vehicle will be described.
<Vehicle>
As shown in FIG. 1, the vehicle 10 includes a vehicle body 11, a first sensor 12, a second sensor 13, and a control device 14. The vehicle 10 of this embodiment is configured to autonomously move. The vehicle 10 may move along the generated route. The vehicle 10 may track a predetermined tracking target. Vehicle 10 is, for example, an industrial vehicle, a transport vehicle, or a passenger car. Industrial vehicles include forklifts and towing tractors.

In this embodiment, the first sensor 12 and the second sensor 13 are the same. Sensors 12 and 13 can detect the two-dimensional position of an object. In this embodiment, LIDAR (Laser Imaging Detection and Ranging) is used as the sensors 12 and 13. The sensors 12 and 13 are distance meters that irradiate the surrounding area with a laser and receive reflected light reflected by a detection point that is a portion hit by the laser. Lasers reflect off the surface of objects. The detection point represents a part of the surface of the object.

As shown in FIG. 2, the sensors 12 and 13 emit laser light at an angle corresponding to the angular resolution θ2 within the range of the viewing angle θ1. The viewing angle θ1 of the sensors 12 and 13 is less than 360°. The viewing angle θ1 of the sensors 12 and 13 is, for example, 270°. The angular resolution θ2 is, for example, 30°. The sensors 12 and 13 are arranged so as to irradiate laser beams while changing the irradiation angle in the horizontal direction. The sensors 12 and 13 irradiate laser beams while changing the irradiation angle within a viewing angle θ1 centered on the sensors 12 and 13. The range defined by the viewing angle θ1 and the reachable distance of the laser is the detectable range of the sensors 12 and 13.

One period is defined as one scan of the range of viewing angle θ1 by the sensors 12 and 13. The detection results of the sensors 12 and 13 can be expressed as a distance data group. The distance data group includes a plurality of distance data detected by the sensors 12 and 13 during one cycle. With the sensors 12 and 13 of this embodiment, ten distance data corresponding to the angular resolution θ2 can be obtained during one cycle. The distance data group consists of 10 pieces, for example {1.0, 1.5, 0, 1.2, 1.8, 1.9, 0, 0.8, 1.5, 1.0}. It is an array of numbers. Each of the ten numerical values is distance data indicating the distance to the detection point. If no reflected light is received even after irradiating a laser, the distance data becomes 0. The order of the distance data included in the distance data group represents the angle from the reference angle. The reference angle is predetermined. If the angular resolution θ2 is 30°, the first distance data is 0°, the second distance data is 30°, and the third distance data is 60°. In this way, the later the distance data included in the distance data group is, the larger the angle from the reference angle becomes. Since the distance data group is data that associates distance data with angles, it can be said to be a set of data that represents the positions of detection points with the sensors 12 and 13 as the origin in a two-dimensional polar coordinate system. It can be said that the sensors 12 and 13 detect the position of a detection point representing a part of the surface of an object in a two-dimensional coordinate system. The distance data group that is the detection result of the first sensor 12 is referred to as a first distance data group. Let distance data included in the first distance data group be first distance data. The distance data group that is the detection result of the second sensor 13 is referred to as a second distance data group. Let distance data included in the second distance data group be second distance data.

As shown in FIG. 3, the first sensor 12 and the second sensor 13 are arranged apart from each other. The first sensor 12 is arranged further forward of the vehicle 10 than the second sensor 13 is. The first sensor 12 is arranged so that the viewing angle θ1 is equal in the left-right direction of the vehicle 10. The viewing angle θ1 of the first sensor 12 extends by 135° on each of the left and right sides of the vehicle 10. The blind spot of the first sensor 12 is the rear direction of the vehicle 10. The second sensor 13 is arranged so that the viewing angle θ1 is equal in the left-right direction of the vehicle 10. The viewing angle θ1 of the second sensor 13 extends by 135° on each of the left and right sides of the vehicle 10. The blind spot of the second sensor 13 is in the front direction of the vehicle 10. The first sensor 12 and the second sensor 13 are arranged so that their blind spots face each other. The detection point P1 by the first sensor 12 is defined as the first detection point P1. The detection point P2 by the second sensor 13 is defined as a second detection point P2.

As shown in FIG. 1, the control device 14 includes a processor 15 and a storage section 16. The storage unit 16 includes a RAM (Random Access Memory) and a ROM (Read Only Memory). The storage unit 16 stores program codes or instructions configured to cause the processor 15 to execute processes. Storage 16, or computer readable media, includes any available media that can be accessed by a general purpose or special purpose computer. The control device 14 may be configured by a hardware circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array). The control device 14, which is a processing circuit, may include one or more processors that operate according to a computer program, one or more hardware circuits such as ASIC or FPGA, or a combination thereof.

<Virtual sensor>
As shown in FIG. 4, the control device 14 can derive the position of the virtual detection point P3 in a two-dimensional polar coordinate system with the virtual sensor IS as the origin from the first distance data group and the second distance data group. can. The virtual sensor IS is a virtual sensor generated by combining the first distance data group and the second distance data group.

The viewing angle θ3 of the virtual sensor IS is 360°. The angular resolution θ4 of the virtual sensor IS is 30°. The virtual sensor IS has a wider viewing angle θ3 than the sensors 12 and 13, and the same angular resolution θ4 as the sensors 12 and 13. The control device 14 derives a virtual distance data group detected by the virtual sensor IS when the virtual sensor IS is placed at the virtual generation point IP. Like the distance data group, the virtual distance data group is an array of a plurality of numerical values. The numerical values included in the virtual distance data group are virtual distance data indicating the distance to the virtual detection point P3. The order of the virtual distance data included in the virtual distance data group represents the angle from the reference angle.

If the virtual detection point P3 from which distance is predicted to be detected when the virtual sensor IS is placed at the virtual generation point IP overlaps the detection points P1 and P2, the control device 14 uses the virtual detection point as virtual distance data. Distance data to detection points P1 and P2 that overlap with point P3 is used. When the virtual detection point P3 and the detection points P1 and P2 do not overlap, the control device 14 uses distance data as virtual distance data from the virtual detection point P3 to the detection points P1 and P2 located in the predetermined range A1. Use. The predetermined range A1 is a range in which the detection points P1 and P2 can be regarded as a virtual detection point P3. The predetermined range A1 is, for example, a circular range centered on the virtual detection point P3. If the detection points P1 and P2 located within the predetermined range A1 from the virtual detection point P3 do not exist, the virtual distance data is 0. As described above, distance data is used as the virtual distance data.

The control device 14 recognizes the position of the object based on the virtual distance data group. The control device 14 may recognize the position of the object in the Cartesian coordinate system by converting the virtual distance data into coordinates in the Cartesian coordinate system. The control device 14 may estimate its own position from the position of the recognized object. The self-position is the coordinates of the vehicle 10 in the map data. The control device 14 may perform control to avoid contact between the vehicle 10 and the object based on the recognized position of the object. For example, the control device 14 may perform control to avoid objects or control to decelerate the vehicle 10. If the vehicle 10 has a person on board, a warning may be given to the person. In this way, the control performed by the control device 14 based on the recognized position of the object is arbitrary.

<Control performed when the control device generates a virtual sensor>
The control performed by the control device 14 when generating the virtual sensor IS will be described. This control is repeatedly executed at a predetermined control cycle during startup of the vehicle 10.

As shown in FIG. 5, in step S1, the control device 14 acquires a first distance data group from the first sensor 12.
Next, in step S2, the control device 14 calculates a first average value D1 that is an average value of the first distance data. The first average value D1 is the average value of the distances to the plurality of first detection points P1 detected by the first sensor 12 in one cycle.

Next, in step S3, the control device 14 acquires a second distance data group from the second sensor 13.
Next, in step S4, the control device 14 calculates a second average value D2 that is an average value of the second distance data. The second average value D2 is the average value of the distances to the plurality of second detection points P2 detected by the second sensor 13 in one cycle.

Next, in step S5, the control device 14 calculates the position of the virtual generation point IP. The virtual generation point IP is the position of the virtual sensor IS. The virtual generation point IP is the origin of a two-dimensional polar coordinate system represented by the virtual distance data group. In this embodiment, the virtual generation point IP is set within the range between the first sensor 12 and the second sensor 13.

As shown in FIG. 6, the virtual generation point IP is set between the first sensor 12 and the second sensor 13. The control device 14 sets a virtual generation point IP on the virtual line segment L1 connecting the first sensor 12 and the second sensor 13. That is, the virtual generation point IP moves on a straight line between the origin of the polar coordinate system representing the position of the first detection point P1 and the origin of the polar coordinate system representing the position of the second detection point P2. The virtual generation point IP of this embodiment moves in the longitudinal direction of the vehicle 10. The center position of the line segment L1, that is, the center position between the first sensor 12 and the second sensor 13 is defined as a reference position PS.

The control device 14 sets a virtual generation point IP at a position where the line segment L1 is divided into an average value D1: an average value D2. That is, the ratio between the distance from the first sensor 12 to the virtual generation point IP and the distance from the second sensor 13 to the virtual generation point IP matches the ratio between the first average value D1 and the second average value D2.

If the first average value D1 and the second average value D2 are the same value, the virtual generation point IP is set to the reference position PS. If the first average value D1 is smaller than the second average value D2, the distance from the virtual generation point IP to the first sensor 12 will be shorter than the distance from the virtual generation point IP to the second sensor 13. When the first average value D1 is smaller than the second average value D2, the distance from the first sensor 12 to the object is shorter than the distance from the second sensor 13 to the object. Therefore, the virtual generation point IP moves between the first sensor 12 and the second sensor 13 so as to approach the object.

As shown in FIG. 5, next, in step S6, the control device 14 sets the virtual generation point IP at the position calculated in step S5.
Next, in step S7, the control device 14 derives a virtual distance data group when the virtual sensor IS is placed at the virtual generation point IP set in step S6. As described above, the control device 14 derives a virtual distance data group using the first distance data group and the second distance data group. Since the virtual generation point IP is the position of the virtual sensor IS, the virtual sensor IS moves to approach the object.

[Operation of this embodiment]
As shown in FIG. 7, assume that the vehicle 10 passes between two walls 21 and 22. The vehicle 10 passes between the two walls 21, 22 while the distances from the two sensors 12, 13 to the two walls 21, 22 remain constant. An obstacle 23 is located between the two walls 21 and 22. Obstacle 23 is provided along wall 22. The two walls 21 and 22 and the obstacle 23 are examples of objects.

When the obstacle 23 does not enter the detectable range of the sensors 12 and 13, the sensors 12 and 13 detect only the walls 21 and 22. In this case, the first average value D1 and the second average value D2 are the same value. The position of the virtual sensor IS is the reference position PS.

When the vehicle 10 moves, the obstacle 23 enters the detectable range of the first sensor 12 . Since the distance from the first sensor 12 to the obstacle 23 is shorter than the distance from the first sensor 12 to the wall 22, the value of the first average value D1 becomes smaller. The position of the virtual sensor IS moves from the reference position PS toward the first sensor 12 so as to approach the obstacle 23.

When the distance from the first sensor 12 to the obstacle 23 is shorter than the distance from the second sensor 13 to the obstacle 23, the first average value D1 is smaller than the second average value D2. In this case, the position of the virtual sensor IS approaches the obstacle 23 from the reference position PS according to the ratio between the first average value D1 and the second average value D2. At this time, the distance from the first sensor 12 to the virtual sensor IS is shorter than the distance from the second sensor 13 to the virtual sensor IS.

When the distance from the second sensor 13 to the obstacle 23 is shorter than the distance from the first sensor 12 to the obstacle 23, the second average value D2 is smaller than the first average value D1. In this case, the position of the virtual sensor IS approaches the obstacle 23 from the reference position PS according to the ratio between the first average value D1 and the second average value D2. At this time, the distance from the second sensor 13 to the virtual sensor IS is shorter than the distance from the first sensor 12 to the virtual sensor IS.

As described above, the control device 14 moves the position of the virtual sensor IS from the reference position PS to approach the obstacle 23. In other words, the control device 14 moves the position of the virtual sensor IS from the reference position PS to approach the sensors 12 and 13 near the obstacle 23.

Note that when a plurality of objects exist around the vehicle 10, there may be an object from which the virtual sensor IS moves away due to the movement of the virtual sensor IS. The object that influences the first average value D1 and the second average value D2 is the object that has the greatest influence on the control of the vehicle 10. If there are multiple objects around the vehicle 10, the virtual sensor IS will approach the object that has the greatest influence.

As shown in FIG. 8, when the position of the virtual sensor IS is kept constant, the expression angle θ6 that expresses the object 24 with the virtual sensor IS as the origin is greater than the expression angle θ5 that expresses the object 24 with the first sensor 12 as the origin. There is a risk that it will become narrower. The expression angle is an angle that represents the range occupied by the object 24 when viewed from the origin of the coordinate system. As can be understood from FIG. 8, the expression angle θ6 when the virtual sensor IS is the origin is narrower than the expression angle θ5 when the first sensor 12 is the origin. If the expression angle is narrow, there is a risk that the recognition accuracy of the object 24 by the control device 14 will decrease, and this may lead to a decrease in self-position estimation accuracy. When the representation angle is narrow, the number of detection points included in the range of the representation angle decreases, making it difficult to recognize the object. In the example shown in FIG. 8, the number of virtual detection points P3 included in the range of expression angle θ6 is smaller than the number of first detection points P1 included in expression angle θ5, so the virtual sensor IS detects the object. There is a risk that object recognition accuracy may decrease due to recognition.

In contrast, in this embodiment, the position of the virtual sensor IS moves from the reference position PS to approach the object. Therefore, the position of the virtual sensor IS approaches the first sensor 12. Thereby, it is possible to suppress the expression angle θ6 of the virtual sensor IS from becoming narrower.

[Operation of this embodiment]
(1) The control device 14 moves the position of the virtual sensor IS so that it approaches the object. Thereby, narrowing of the expression angle can be suppressed.

(2) The control device 14 moves the position of the virtual sensor IS on the virtual line segment L1 connecting the first sensor 12 and the second sensor 13. When the virtual sensor IS is moved on the line segment L1, the virtual sensor IS approaches one of the two sensors 12 and 13. Therefore, the detection points P1 and P2 are likely to be included in the predetermined range A1, and the object represented by the detection points P1 and P2 can be easily represented by the virtual detection point P3. Therefore, it is possible to suppress a decrease in object recognition accuracy.

(3) The control device 14 determines that the ratio of the distance from the first sensor 12 to the virtual sensor IS to the distance from the second sensor 13 to the virtual sensor IS is the ratio of the first average value D1 to the second average value D2. The virtual sensor IS is moved to match the . The shorter the distance between the sensors 12, 13 and the object, the smaller the average value of the distances to the detection points P1, P2. By moving the virtual sensor IS according to the ratio between the first average value D1 and the second average value D2, the virtual sensor IS can be brought closer to the object.

[Example of change]
The embodiment can be modified and implemented as follows. The embodiments and the following modification examples can be implemented in combination with each other within a technically consistent range.

The control device 14 may move the virtual generation point IP in the left-right direction of the vehicle 10. In this case, the control device 14 calculates the position of the virtual generation point IP based on the distance data for the right direction of the vehicle 10 and the distance data for the left direction of the vehicle 10. For example, the control device 14 calculates the average value of the distance to the detection points P1, P2 in a range of 135° to the right of the vehicle 10 among the viewing angles θ1 of the sensors 12 and 13, and the viewing angle θ1 of the sensors 12 and 13. Of these, the average value of the distances to the detection points P1 and P2 within a range of 135 degrees with respect to the left direction of the vehicle 10 is calculated. The average value of the distances to the detection points P1 and P2 within the range of 135° to the right of the vehicle 10 in the viewing angle θ1 of the sensors 12 and 13 is defined as the right average value. The average value of the distances to the detection points P1 and P2 in the range of 135° to the left of the vehicle 10 in the viewing angle θ1 of the sensors 12 and 13 is defined as the left average value. When the right average value is smaller than the left average value, the control device 14 sets the virtual generation point IP to the right of the vehicle 10 from the line segment L1. When the left average value is smaller than the right average value, the control device 14 sets the virtual generation point IP to the left of the vehicle 10 than the line segment L1. For example, a range that extends to both the left and right sides of the vehicle 10 with the line segment L1 as the center is set as the range in which the virtual generation point IP can move in the left and right direction, and the range is set according to the ratio of the right average value and the left average value. You may also set the position of the virtual generation point IP at . In this case, line segment L1 is the reference position. When moving the virtual generation point IP in the left-right direction of the vehicle 10, the control device 14 may move the virtual generation point IP in the front-rear direction of the vehicle 10, or move the virtual generation point IP in the front-rear direction of the vehicle 10. You don't have to let it happen.

○The control device 14 may convert the distance data into coordinates of an orthogonal coordinate system. Since the polar coordinate system and the orthogonal coordinate system are mutually convertible, distance data can be converted into coordinates in the orthogonal coordinate system. The orthogonal coordinate system is a coordinate system in which the Y axis is the longitudinal direction of the vehicle 10 and the X axis is the horizontal direction of the vehicle 10. The Y coordinate is the distance in the longitudinal direction of the vehicle 10 to the detection points P1 and P2. The X coordinate is the distance in the left-right direction of the vehicle 10 to the detection points P1 and P2. The control device 14 may set the average value of the distances in the Y-axis direction to the plurality of first detection points P1 detected by the first sensor 12 in one cycle as the first average value D1. The control device 14 may set the average value of the distances in the Y-axis direction to the plurality of second detection points P2 detected by the second sensor 13 in one cycle as the second average value D2. The control device 14 may then set the position of the virtual sensor IS based on these average values.

The control device 14 may derive the position of the virtual detection point P3 in a two-dimensional orthogonal coordinate system having the virtual sensor IS as the origin from the first distance data group and the second distance data group. In this case, the control device 14 may convert the distance data into coordinates of an orthogonal coordinate system, and then derive the position of the virtual detection point P3 in a two-dimensional orthogonal coordinate system with the virtual sensor IS as the origin. That is, the two-dimensional coordinate system having the virtual sensor IS as its origin may be a polar coordinate system or a rectangular coordinate system.

○ When calculating the average value of the distances to the plurality of detection points P1 and P2 detected by the sensors 12 and 13 in one cycle, the control device 14 excludes distance data with a value of 0 and calculates the average value. It's okay.

- The virtual generation point IP may be set at a position shifted from the line segment L1. For example, the virtual generation point IP may be set on a line segment that is parallel to the line segment L1 and is a predetermined distance away from the line segment L1.

The sensors 12 and 13 may be of any type as long as they can detect the positions of the detection points P1 and P2 in a two-dimensional coordinate system. For example, as the sensors 12 and 13, a radar, a stereo camera, or a ToF (Time Of Flight) camera can be used. The two-dimensional coordinate system of the detection points P1 and P2 may be a polar coordinate system or a rectangular coordinate system.

The first sensor 12 and the second sensor 13 may have different viewing angles θ1 or may have different angular resolutions θ2. The first sensor 12 and the second sensor 13 may be different types of sensors. For example, LIDAR may be used as the first sensor 12 and a stereo camera may be used as the second sensor 13.

The angular resolution θ4 of the virtual sensor IS may be higher or lower than the angular resolution θ2 of the sensors 12 and 13.
The vehicle 10 may be operated by a person riding in the vehicle 10.

IS...virtual sensor, L1...line segment, P1...first detection point, P2...second detection point, P3...virtual detection point, PS...reference position, 10...vehicle, 12...first sensor, 13...second sensor , 14...control device.

Claims (3)

a first sensor that detects the position of a first detection point representing a part of the surface of the object in a two-dimensional coordinate system;
a second sensor that detects a position in a two-dimensional coordinate system of a second detection point representing a part of the surface of the object;
comprising a control device;
The control device includes:
Deriving the position of a virtual detection point in a two-dimensional coordinate system with the virtual sensor as the origin based on the detection result of the first sensor and the detection result of the second sensor,
The vehicle moves the virtual sensor so as to approach the object from a reference position based on a detection result of the first sensor and a detection result of the second sensor. The vehicle according to claim 1, wherein the control device moves the virtual sensor on a virtual line segment connecting the first sensor and the second sensor. The control device includes:
Calculating a first average value that is an average value of distances to the plurality of first detection points detected by the first sensor in one cycle,
Calculating a second average value that is an average value of distances to the plurality of second detection points detected by the second sensor in one cycle,
The virtual sensor is configured such that the ratio of the distance from the first sensor to the virtual sensor and the distance from the second sensor to the virtual sensor matches the ratio of the first average value and the second average value. 3. The vehicle according to claim 2, wherein the vehicle moves a .

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