JP6819161B2 - Coordinate calculation method and coordinate calculation device - Google Patents

Description

The present invention relates to a coordinate calculation method and a coordinate calculation device.

Conventionally, a technique for detecting an object in an observation region by irradiating a surrounding observation region with light from a sensor provided in a vehicle and receiving the reflected light by the sensor has been disclosed (see Patent Document 1).

Japanese Unexamined Patent Publication No. 2015-152428

For example, by using two sensors and overlapping a part of each observation area, it is possible to reduce a position that the observation area does not reach, that is, a so-called blind spot.
However, the detection result in the overlapping region includes an error due to the optical distortion of the sensor, and the coordinates of the object may not be calculated correctly.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a coordinate calculation method and a coordinate calculation device capable of correctly calculating the coordinates of an object.

In the coordinate calculation method according to one aspect of the present invention, the first and second sensors are mounted on the vehicle so that a part of each observation region overlaps with each other. The overlapping region of the observation region is the first region in which the absolute value of the first azimuth obtained by the first sensor is larger than the first value, and the second region in which the absolute value of the second azimuth obtained by the second sensor is larger than the second value. Two regions are included, the overlapping region of the first region and the second region, the region excluding the overlapping region of the first region and the second region from the first region, and the overlap of the first region and the second region from the second region. a region excluding the region, but each present. When the absolute value of the first azimuth is less than or equal to the first value, the coordinates are calculated using the detection result of the first sensor, and when the absolute value of the second azimuth is less than or equal to the second value, the second value is calculated. Coordinates are calculated using the detection result of the sensor. When the absolute value of the first azimuth is larger than the first value and the absolute value of the second azimuth is larger than the second value, the coordinates are determined using the detection result of the first sensor and the detection result of the second sensor. It is calculated , the linear distance of one of the detection results of the first sensor and the second sensor, the azimuth of one of the detection results of the first sensor and the second sensor, and the detection result of the first sensor and the second sensor. Coordinates are calculated using the average value of each vertical distance included in.

According to the present invention, it is possible to correctly calculate the coordinates of an object.

FIG. 1 is a diagram showing an observation region configured around the vehicle of the first embodiment. FIG. 2 is a block diagram showing a configuration of a coordinate calculation device mounted on the vehicle 1. FIG. 3 is a block diagram showing the configuration of each sensor. FIG. 4 is a diagram showing the distortion of the vertical distance d2 that occurs according to the azimuth angle s. FIG. 5 is a flowchart showing the flow of the coordinate calculation method in the first embodiment. FIG. 6 is a diagram showing an observation region in the second embodiment. FIG. 7 is a diagram showing an observation region in a modified example of the second embodiment. FIG. 8 is a diagram showing an observation region in another modification of Example 2.

Hereinafter, embodiments will be described with reference to the drawings. The same members are designated by the same reference numerals, and the description thereof will be omitted again.

(Example 1)
The vehicle 1 shown in FIG. 1 is capable of detecting surrounding objects. Specifically, the sensor 111 arranged at the front of the vehicle 1 detects an object existing in the observation region 21 in front of the vehicle 1. Further, the sensor 112 arranged on the left side of the vehicle 1 detects an object existing in the observation area 22 on the left side of the vehicle 1. Further, the sensor 113 arranged at the rear of the vehicle 1 detects an object existing in the observation area 23 behind the vehicle 1. Further, the sensor 114 arranged on the right side of the vehicle 1 detects an object existing in the observation area 24 on the right side of the vehicle 1.

Each observation area is set to, for example, a range of 150 degrees centered on the front direction of the sensor. As a result, the adjacent observation areas partially overlap, and it is possible to detect objects all around the vehicle 1. That is, the sensors corresponding to the adjacent observation regions are mounted on the vehicle 1 so that a part of each observation region overlaps. The details of the overlapping area will be described later.

As shown in FIG. 2, the coordinate calculation device includes a sensor 111 at the front of the vehicle 1, a sensor 112 at the left side of the vehicle 1, a sensor 113 at the rear of the vehicle 1, and a sensor 114 at the right side of the vehicle 1. , A coordinate calculation unit 12 that transmits a drive signal to each sensor, receives a detection result from each sensor, and calculates the coordinates of an object.

As shown in FIG. 3, each sensor 111 to 114 includes a light transmitting unit 1101, an image sensor 1102 (light receiving unit), a drive control unit 1103, a measuring unit 1104, and a calculation unit 1105.

The light transmitting unit 1101 irradiates light around the vehicle 1, specifically in the direction of the corresponding observation region. The image sensor 1102 is configured by arranging light receiving elements that receive reflected light from an object that has received light in a two-dimensional matrix, and receives the reflected light. The drive control unit 1103 receives a drive signal from the coordinate calculation unit 12 and drives and controls the light transmission unit 1101 and the image sensor 1102.

The measuring unit 1104 receives from the image sensor 1102 a luminance signal indicating the intensity of the reflected light received by each light receiving element of the image sensor 1102, and based on the luminance signal, the reflection received by each light receiving element of the image sensor 1102. Generates a luminance image consisting of luminance indicating the strength of the signal.

Further, the measuring unit 1104 measures the delay time of the light receiving timing with respect to the light emitting timing for each light receiving element based on the luminance signal. Then, based on the delay time, the distance to the reflection point is measured for each light receiving element, and a distance image consisting of each distance is generated.

The calculation unit 1105 calculates the linear distance d1 from the sensor to the object based on the distance image, and calculates the azimuth angle s and elevation angle g of the object with respect to the normal of the light receiving surface of the image sensor based on the luminance image.

Here, the azimuth angle s is based on the direction of the normal of the light receiving surface of the image sensor (direction of irradiating light) as a reference (0 degree), and the clockwise direction centered on the sensor is plus and counterclockwise in a plan view. It is calculated with the direction as minus. The observation area is set in a range (a range of 150 degrees) in which the azimuth angle s is sandwiched between the direction of +75 degrees and the direction of −75 degrees. That is, the observation region is symmetrical in the horizontal direction with the direction in which the azimuth angle s is 0 degrees as the center.

Further, here, the calculation unit 1105 calculates the vertical distance d2 (hereinafter referred to as the vertical distance d2) between the sensor and the object based on the linear distance d1 and the elevation angle g.

That is, the calculation unit 1105 obtains a detection result consisting of a linear distance d1, an azimuth angle s, an elevation angle g, and a vertical distance d2, and at least the linear distance d1, the azimuth angle s, and the vertical distance d2 (also collectively referred to). Then, the detection result) is transmitted to the coordinate calculation unit 12.

With reference to FIG. 4, the distortion of the vertical distance d2 that occurs according to the azimuth angle s will be described.
In FIG. 4, the horizontal axis represents the azimuth angle s, and the vertical axis represents the vertical distance d2. 0 [degree] on the horizontal axis indicates the direction of the normal of the light receiving surface of the image sensor. The position of 0 [m] on the vertical axis is the position in the vertical direction of the sensor.

Each characteristic line p indicates the detection result of a linear object arranged in the horizontal direction. Since the objects are arranged in the horizontal direction, the vertical distance d2 is originally constant, but the larger the absolute value of the azimuth angle s, the larger the absolute value of the vertical distance d2. That is, the closer to the horizontal end of the observation region, the larger the optical distortion, and the larger the difference (error) between the measured vertical distance d2 and the original vertical distance.

In addition, the end of the observation area having such characteristics also overlaps with the adjacent observation area. For example, when the same object is detected by the sensors 111 and 112, the vertical distance d2 obtained by the sensor 111 and the vertical distance d2 obtained by the sensor 112 may be different. The cause of this phenomenon is considered to be that the azimuth angle s obtained by the sensor 111 and the azimuth angle s obtained by the sensor 112 are different from each other in view of the characteristics shown in FIG.

In this embodiment, in such a case, the same object is detected as the same object by the process described later without erroneously detecting the same object as a different object.

In FIG. 1, for example, the overlapping region A of the observation regions 21 and 22 is a region (first region) in which the absolute value of the azimuth s (first azimuth) obtained by the sensor 111 is 45 degrees (first value) or more. ), That is, the region including the regions A1 and A3 in FIG. 1 is included. Further, the overlapping region A is a region (second region) in which the absolute value of the azimuth s (second azimuth) obtained by the sensor 112 is 45 degrees (second value) or more, that is, the region A2 in FIG. Includes a region consisting of A3. Here, the first value and the second value are the same, but may be different.

In other words, the overlapping region A includes a region A3 in which the first region and the second region overlap. Further, the region A1 is a region obtained by removing the region A3 from the first region, and the region A2 is a region obtained by removing the region A3 from the second region.

Further, the overlapping regions of the observation regions 22 and 23, the overlapping regions of the observation regions 23 and 24, and the overlapping regions of the observation regions 24 and 21 have the same configuration as the overlapping regions A of the observation regions 21 and 22.

Next, with reference to FIG. 5, the coordinate calculation method performed by the coordinate calculation unit 12 will be described.
Here, the coordinate calculation unit 12 refers to the linear distance d1 (hereinafter referred to as the linear distance d11), the azimuth s (hereinafter referred to as the azimuth s1) and the vertical distance d2 (hereinafter referred to as the vertical distance d21) obtained by the sensor 111. ) Is received from the sensor 111. The linear distance d11, the azimuth angle s1 and the vertical distance d21 are collectively referred to as the detection result r1.

Further, the coordinate calculation unit 12 has a linear distance d1 (hereinafter referred to as a linear distance d12), an azimuth angle s (hereinafter referred to as an azimuth angle s2) and a vertical distance d2 (hereinafter referred to as a vertical distance d22) obtained by the sensor 112. Is received from the sensor 112. The linear distance d12, the azimuth angle s2, and the vertical distance d22 are collectively referred to as the detection result r2.

First, the coordinate calculation unit 12 determines whether or not the difference between the linear distances d11 and d12 is equal to or less than the predetermined threshold value th1, that is, whether or not the linear distances d11 and d12 are substantially the same (S1). When the difference in linear distance is larger than the threshold value th1 (S1: NO), the coordinates of the object are calculated based on the detection result r1, and the coordinates of another object are calculated based on the detection result r1 (S3). ), Finish the process.

For example, the coordinates shall be the coordinates of the coordinate system with the center of the vehicle as the origin, the right side of the vehicle as the plus direction of the X axis, the front of the vehicle as the plus direction of the Y axis, and the upper part of the vehicle as the plus direction of the Z axis. Is possible.

When the difference between the linear distances is the threshold value th1 or less (S1: YES), it is determined whether or not the absolute value of the azimuth angle s1 is 45 degrees (first value) or less (S5). When the absolute value of the azimuth angle s1 is 45 degrees (first value) or less (S5: YES), the coordinates of the object are not calculated based on the detection result r2, and the coordinates of the object are calculated based on the detection result r1 (S5: YES). S7), the process is completed. That is, the coordinates of the object in the area A2 of FIG. 1 are calculated based on the detection result r1.

For example, suppose that the coordinates of the object in the area A2 are calculated based on the detection result r2. However, since the vertical distance of the detection result r2 contains many errors, accurate coordinates cannot be obtained. Therefore, more accurate coordinates can be obtained by using the vertical distance of the detection result r1 with a small error instead of using the vertical distance of the detection result r2 containing many errors.

On the other hand, when the absolute value of the azimuth angle s1 is larger than 45 degrees (first value) (S5: NO), it is determined whether or not the absolute value of the azimuth angle s2 is 45 degrees (second value) or less (S9). ). When the absolute value of the azimuth angle s2 is 45 degrees or less (S9: YES), the coordinates of the object are not calculated based on the detection result r1 and the coordinates of the object are calculated based on the detection result r2 (S11). Finish. That is, the coordinates of the object in the region A1 of FIG. 1 are calculated based on the detection result r2.

For example, suppose that the coordinates of the object in the area A1 are calculated based on the detection result r1. However, since the vertical distance of the detection result r1 contains many errors, accurate coordinates cannot be obtained. Therefore, more accurate coordinates can be obtained by using the vertical distance of the detection result r2 having a small error instead of using the vertical distance of the detection result r1 containing many errors.

On the other hand, when the absolute value of the azimuth angle s2 is larger than 45 degrees (second value) (S9: NO), whether or not the difference between the vertical distances d21 and d22 is equal to or less than the predetermined threshold value th2, that is, the vertical direction. It is determined whether or not the distances d21 and d22 are substantially the same (S13).

When the difference in the vertical distance is larger than the threshold value th2 (S13: NO), the coordinates of the object are calculated based on the detection result r1, and the coordinates of another object are calculated based on the detection result r1 (S13: NO). S3), the process is completed. If the difference in the vertical distance is larger than the threshold value th2 (S13: NO), it is excluded from the observation target and the coordinates need not be calculated.

On the other hand, when the difference in the vertical distance is equal to or less than the threshold value th2 (S13: YES), the coordinates of the object are calculated using the detection results r1 and r2 (S15), and the process is completed.

In step S15, for example, the average value dav of the vertical distances d21 and d22 is calculated, the linear distance included in one of the two detection results, the azimuth angle included in one of the two detection results, and the average value dav. Coordinates are calculated based on (S15).

If one of the detection results is selected and used, the vertical distance included in the detection result may contain more error than the vertical distance included in the unselected detection result, and the coordinates. The error of is also large. Therefore, in this embodiment, by using both detection results, it is possible to obtain more accurate coordinates with less error.

In the above example, the coordinate calculation method based on the detection results of the sensors 111 and 112 has been described, but the coordinate calculation method based on the detection results of the sensors 112 and 113, the coordinate calculation method based on the detection results of the sensors 113 and 114, and the sensor. The coordinate calculation method based on the detection results of 114 and 111 is the same as this.

As described above, in the coordinate calculation method of the first embodiment, the surroundings of the vehicle 1 are irradiated with light, and the reflected light is received by the image sensor 1102 to detect the linear distance d1, the azimuth angle s, and the elevation angle g. The result is obtained by the first sensor (sensor 111 of the above example) and the second sensor (sensor 112 of the above example). Then, the coordinates are calculated using each detection result.

The first sensor (111) and the second sensor (112) are mounted on the vehicle so that parts of the observation areas 21 and 22 overlap each other (FIG. 1). The overlapping region A of the observation region is obtained by the first region (A1 + A3) and the second sensor in which the absolute value of the first azimuth obtained by the first sensor (111) is equal to or larger than the first value (45 degrees in the above example). It includes a second region (A2 + A3) in which the absolute value of the second azimuth is equal to or greater than the second value (45 degrees in the above example). In addition, there is an overlapping region (A3) between the first region and the second region.

Then, when the absolute value of the first azimuth angle is equal to or less than the first value (S5: YES), the coordinates are calculated using the detection result of the first sensor (S7). When the absolute value of the second azimuth is equal to or less than the second value (S9: YES), the coordinates are calculated using the detection result of the second sensor (S11). When the absolute value of the first azimuth is larger than the first value and the absolute value of the second azimuth is larger than the second value (S9: NO), the detection result of the first sensor and the detection result of the second sensor are displayed. The coordinates are calculated using (S15).

Therefore, the coordinates of the object in the region (A1) excluding the overlapping region (A3) from the first region are calculated based on the detection result of the second sensor with less error, and the overlapping region (A3) is excluded from the second region. The coordinates of the object in the region (A2) are calculated based on the detection result of the first sensor with less error. As a result, more accurate coordinates can be obtained.

Further, since the coordinates of the object in the overlapping region (A3) are calculated based on the detection results of the first and second sensors, not based on only one of the detection results, more accurate coordinates can be obtained. it can.

Further, the absolute value of the first azimuth is larger than the first value and the absolute value of the second azimuth is larger than the second value (S9: NO), and the vertical distance of the detection result of the first sensor and the vertical distance of the second sensor. When the difference between the detection result and the vertical distance is equal to or less than the predetermined threshold value th2 (S13: YES), the coordinates are calculated using each detection result (S15). As a result, the coordinates of the object can be obtained only when the objects detected by the first and second sensors can be determined to be the same object (S13: YES).

Further, the average value dav of each vertical distance is calculated, and the coordinates are calculated using one linear distance of the two detection results, one azimuth angle of the two detection results, and the average value dav (S15). .. Therefore, the coordinates of the object can be obtained only when the objects detected by the first and second sensors can be determined to be the same object (S13: YES).

(Example 2)
Next, Example 2 will be described. Since the configuration of the overlapping region of the observation region is different from that of the first embodiment and the other parts are the same in the second embodiment, the description will be focused on the difference.

In FIG. 6, the intersection P of the outer edge of the observation area 21 and the outer edge of the observation area 22 is shown. The first region composed of the regions A1 and A3 is still a region in which the absolute value of the azimuth angle s (first azimuth angle) obtained by the sensor 111 is equal to or higher than the first value, but the first value (first value). 1 azimuth angle) indicates the azimuth from the sensor 111 to the intersection P. As a result, the first value is larger than the first value of Example 1, 45 degrees.

Further, the second region composed of the regions A2 and A3 is still a region in which the absolute value of the azimuth angle s (second azimuth angle) obtained by the sensor 112 is equal to or higher than the second value, but the second value. (Second azimuth angle) indicates the azimuth from the sensor 112 to the intersection P. As a result, the second value is larger than the second value of Example 1, 45 degrees.

As a result, the area of the region A3 can be made smaller than that of the first embodiment. As a result, even when the coordinates of the object are calculated, the number of times the average value is calculated can be reduced, and the calculation load can be reduced.

(Modified Example of Example 2)
The arrangement of the sensors is not limited to the arrangements of Examples 1 and 2, and for example, as shown in FIG. 7, the sensors 112 and 114 may be shifted forward. Even in this case, the area of the region A3 can be reduced and the calculation load can be reduced by setting the first and second azimuth angles to indicate the directions to the intersection P, respectively.

(Another variant of Example 2)
Further, as shown in FIG. 8, the sensors may be arranged at the left and right ends of the front portion and the left and right ends of the rear portion of the vehicle. Even in this case, by setting the first and second azimuth angles to indicate the azimuth to the intersection P, the area of the region A3 can be reduced and the calculation load can be reduced.

Although not shown, the number of sensors is not limited to 4, and may be 2 or 5 or more. Further, the above technique may be applied to a part of a plurality of sensors, for example, two of three sensors.

Further, in the above embodiment, the case where the observation regions overlap in the horizontal direction has been described, but the observation regions may overlap in other directions, for example, in the axial direction around the traveling direction of the vehicle. In this case, the sensors may be arranged at the left and right ends of the roof of the vehicle.

Although embodiments of the present invention have been described above, the statements and drawings that form part of this disclosure should not be understood to limit the invention. Various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art from this disclosure.

1 Vehicle 111-114 Sensor 12 Coordinate calculation unit 1101 Light transmission unit 1102 Image sensor 1103 Drive control unit 1104 Measurement unit 1105 Calculation unit 21, 22, 23, 24 Observation area d1 Straight line distance d2 Vertical distance s Azimuth g Elevation angle th1 Straight line Threshold for difference in distance th2 Threshold for difference in vertical distance r1 Detection result by sensor 111 r2 Detection result by sensor 112 d11 Linear distance d12 included in detection result r1 Linear distance s1 detection result included in detection result r2 Azimuth angle s2 included in r1 Azimuth angle d21 included in detection result r2 Vertical distance included in detection result r1 d22 Vertical distance included in detection result r2

Claims (4)

By irradiating the surroundings of the vehicle with light and receiving the reflected light from the object that received the light with the image sensor, the linear distance to the object, the azimuth and elevation angle with respect to the normal of the light receiving surface of the image sensor, An object that calculates the coordinates of the object using the first sensor and the second sensor that obtain the detection results including the vertical distance between the object and the object, which are calculated based on the linear distance and the elevation angle, respectively. In the coordinate calculation method
The first and second sensors are mounted on the vehicle so that a part of each observation region overlaps, and the overlapping region of the observation region has an absolute value of the first azimuth obtained by the first sensor. A first region larger than the first value, a second region in which the absolute value of the second azimuth obtained by the second sensor is larger than the second value is included, and the overlapping region of the first region and the second region and the said A region excluding the overlapping region of the first region and the second region from the first region and a region excluding the overlapping region of the first region and the second region from the second region exist, respectively.
When the absolute value of the first azimuth is equal to or less than the first value, the coordinates are calculated using the detection result of the first sensor.
When the absolute value of the second azimuth is equal to or less than the second value, the coordinates are calculated using the detection result of the second sensor.
When the absolute value of the first azimuth angle is larger than the first value and the absolute value of the second azimuth angle is larger than the second value, the detection result of the first sensor and the detection result of the second sensor The coordinates are calculated using the above, and the average value of each vertical distance included in the detection result of the first sensor and the detection result of the second sensor is calculated, and the detection result of the first sensor and the first sensor are calculated. It is characterized in that coordinates are calculated using the linear distance of one of the detection results of the two sensors, the azimuth of one of the detection results of the first sensor and the detection result of the second sensor, and the average value. Coordinate calculation method. Absolute value is larger than said second value of large and said second azimuth angle absolute value than the first value of the first azimuth angle, the vertical distance between the second included in the detection result of the first sensor If the difference between the vertical distance contained in the detection result of the sensor is below a predetermined threshold value, the coordinate calculation method according to claim 1, wherein the calculating the coordinates by using the detection results. The first value from the first sensor, which indicates the direction of the outer edge of the intersection of the observation area of the outer edge and the second sensor of the observation area of the first sensor,
The coordinate calculation method according to claim 1 or 2 , wherein the second value indicates an orientation from the second sensor to the intersection. By irradiating the surroundings of the vehicle with light and receiving the reflected light from the object that received the light with the image sensor, the linear distance to the object, the azimuth and elevation angle with respect to the normal of the light receiving surface of the image sensor, An object that calculates the coordinates of the object using the first sensor and the second sensor that obtain the detection results including the vertical distance between the object and the object, which are calculated based on the linear distance and the elevation angle, respectively. In the coordinate calculation device
The first and second sensors are mounted on the vehicle so that a part of each observation region overlaps, and the overlapping region of the observation region has an absolute value of the first azimuth obtained by the first sensor. A first region larger than the first value, a second region in which the absolute value of the second azimuth obtained by the second sensor is larger than the second value is included, and the overlapping region of the first region and the second region and the said A region excluding the overlapping region of the first region and the second region from the first region and a region excluding the overlapping region of the first region and the second region from the second region exist, respectively.
When the absolute value of the first azimuth is equal to or less than the first value, the coordinates are calculated using the detection result of the first sensor, and the absolute value of the second azimuth is equal to or less than the second value. In this case, the coordinates are calculated using the detection result of the second sensor, and the absolute value of the first azimuth is larger than the first value and the absolute value of the second azimuth is larger than the second value. Provided a coordinate calculation unit that calculates coordinates using the detection result of the first sensor and the detection result of the second sensor .
The coordinate calculation unit
The average value of each vertical distance included in the detection result of the first sensor and the detection result of the second sensor is calculated, and the linear distance of one of the detection result of the first sensor and the detection result of the second sensor. When the coordinate calculation apparatus characterized that you calculate coordinates using the one the azimuth angle of the detection result of the detection result of the first sensor and the second sensor, and said average value.

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