JP6499909B2 - Obstacle detection device and method - Google Patents

Description

  The present invention relates to a moving object obstacle detection apparatus and method.

  A moving body in which a laser device (for example, a laser range finder) is mounted on a traveling vehicle and autonomously traveling or semi-autonomously traveling is detected by detecting a road surface or an obstacle ahead is already disclosed (for example, Patent Documents 1 and 2). ).

JP 2011-150473 A JP 2012-159954 A

The moving bodies of Patent Documents 1 and 2 are equipped with a laser device that detects an obstacle position and a road surface position from a time difference between incident light and reflected light.
However, if the obliquely downward irradiation angle of the laser light emitted by the laser device is small (for example, less than 2 degrees), the reflected light from the road surface can hardly be detected. For this reason, the conventional laser device can detect an obstacle at a short distance (for example, less than 30 m) from the traveling vehicle, but cannot detect an obstacle at a longer distance than that, and thus it is difficult to travel at a high speed.

Therefore, in addition to the conventional laser device (short-distance laser device), it has been studied to add another laser device (far-distance laser device) in order to detect a long-distance obstacle.
As described above, the long-distance laser device detects almost no reflected light from the road surface because the obliquely downward irradiation angle of the laser light to be irradiated is small, but the reflected light from the obstacle is high in intensity. Can be detected.
However, if a highly reflective surface such as a white line lane is drawn on the road surface, the reflected light may be detected by the long-range laser device and erroneously detected as an obstacle.
For this reason, since a white line is erroneously detected as an obstacle on a travel path (for example, a vehicle-dedicated road) in which white line lanes are continuous, there is a possibility that it is difficult to travel at high speed.

  The present invention has been developed to solve the above-described problems. That is, an object of the present invention is to detect an obstacle at a long distance without erroneous detection even if a highly reflective (for example, white line) is drawn on a road surface at a long distance (for example, 30 m or more) from a traveling vehicle. An object of the present invention is to provide an obstacle detection apparatus and method.

According to the present invention, a short distance laser device and a long distance laser device mounted on a traveling vehicle traveling on a road surface,
A data processing device for detecting an obstacle position,
The short distance laser device irradiates a first laser beam on a short distance range close to the traveling vehicle, detects the obstacle position and the road surface position from the time difference between the incident light and the reflected light,
The long-distance laser device irradiates a second laser beam to an overlapping range that overlaps the short-distance range and a long-distance range that is farther than the short-distance range, and the failure is determined based on a time difference between the incident light and reflected light. Detect the object position,
The data processing device creates a local environment map ahead of the traveling vehicle using the detection result in the overlapping range, and the obstacle position mismatch detected by the short-range laser device and the long-range laser device. Extract the position,
In the overlapping range, the non-coincidence position that is located on a straight line is detected as a white line position,
Of the unmatched positions detected by the long-range laser device, extract the obstacle position located on an extension line of the white line position as a target position,
The obstacle in which the target position is erroneously detected when the distance of the target position from the traveling vehicle is equal to or greater than a first threshold, the number of detections is equal to or greater than a second threshold, and the detection width is equal to or smaller than a third threshold. Judging the position,
An obstacle detection apparatus is provided, wherein the obstacle position is erased from the local environment map .

The short-range laser device irradiates the first laser beam forward at an obliquely downward first angle, and the first angle is an angle range in which a road surface position and an obstacle position can be detected from the time difference,
The long-distance laser device irradiates the second laser light forward at an obliquely downward second angle, and the second angle is an angle range in which reflected light from the road surface cannot be detected.

The angle range of the first angle θ1 is not less than 2 degrees and not more than 60 degrees,
The angle range of the second angle θ2 is preferably greater than 0 degree and less than or equal to 3 degrees.

According to the present invention, (A) a short-range laser device, a long-range laser device, and a data processing device are prepared,
(B) The short-range laser device irradiates a first laser beam to a short-range range close to the traveling vehicle, detects an obstacle position and a road surface position from a time difference between the incident light and the reflected light,
(C) By the long-distance laser device, the overlapping range overlapping the short-distance range and the long-distance range far from the short-distance range are irradiated with the second laser light, and the time difference between the incident light and the reflected light detecting said obstacle position from
(D) By using the detection result in the overlapping range by the data processing device,
(D1) Create a local environment map ahead of the traveling vehicle from the road surface position and the obstacle position detected by the short-range laser device and the long-range laser device,
(D2) Compare each detected obstacle position in the local environment map;
(D3) Extracting the inconsistent position of the obstacle position by the comparison,
(E1) Among the disagreement positions, those located on a straight line in the overlapping range are detected as white line positions,
(E2) Among the mismatched positions, the obstacle position located on an extension line of the white line position in the long distance range is extracted as a target position,
(E3) The target position is erroneously detected when the distance from the traveling vehicle of the target position is greater than or equal to the first threshold, the number of detections is greater than or equal to the second threshold, and the detection width is less than or equal to the third threshold. There is provided an obstacle detection method characterized by determining an obstacle position and deleting the obstacle position from the local environment map .

  According to the above-described apparatus and method of the present invention, the data processing device makes a false detection from the road surface position and the obstacle position detected by the short-range laser device and the long-range laser device using the detection result in the overlapping range. Obstacle location is identified and erased. Therefore, even when a highly reflective object (for example, a white line) is drawn on a road surface at a long distance (for example, 30 m or more) from the traveling vehicle, an obstacle at a long distance can be detected without erroneous detection.

It is the block diagram (B) with the block diagram (A) of the traveling vehicle provided with the obstacle detection apparatus of this invention. It is explanatory drawing of the measurement range of a short-distance laser apparatus and a long-distance laser apparatus. It is explanatory drawing of the obstacle detection means of a short-distance laser apparatus and a long-distance laser apparatus. It is an example of the measurement result of a short distance laser apparatus. It is an example of the measurement result of a long-distance laser apparatus. It is a schematic diagram of a real environment. It is a flowchart of the obstacle detection method of the present invention. It is explanatory drawing of the obstacle detection method of this invention.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, the same code | symbol is attached | subjected to the common part in each figure, and the overlapping description is abbreviate | omitted.

FIG. 1 is a configuration diagram (A) and a block diagram (B) of a traveling vehicle 1 including an obstacle detection device 10 of the present invention.
In this example, the traveling vehicle 1 is a work vehicle that travels on a road surface 3 with a soil removal device 2 at the front of the vehicle. However, the traveling vehicle 1 is not limited to a work vehicle provided with the earth removing device 2, and may be a mobile body that performs autonomous traveling or semi-autonomous traveling.

  In FIG. 1, the obstacle detection device 10 of the present invention includes a short-range laser device 12, a long-range laser device 14, and a data processing device 16.

The short distance laser device 12 and the long distance laser device 14 are mounted on the traveling vehicle 1.
In this example, the short distance laser device 12 is installed above the earth removal device 2 of the traveling vehicle 1. The installation height H1 of the short distance laser device 12 is preferably higher than the installation height H2 of the long distance laser device 14. The installation heights H1 and H2 are, for example, in the range of 2 to 3 m.

The data processing device 16 is, for example, a computer (PC), and detects the position of the obstacle 4 (obstacle position 5) from the detection data of the short-range laser device 12 and the long-range laser device 14. The detection data includes the position of the road surface 3 (road surface position 6) and the position of the obstacle 4 (obstacle positions 5a and 5b).
The data processing device 16 is mounted on the traveling vehicle 1 in this example. However, the data processing device 16 may be mounted other than the traveling vehicle, and the traveling vehicle 1 may be remotely operated.

  The data processing device 16 uses the detection result in the overlapping range B (see FIG. 2) to detect the detection data (the road surface position 6 and the obstacle position 5a, detected by the short-range laser device 12 and the long-range laser device 14). The obstacle position 5c (see FIG. 4B) erroneously detected from 5b) is specified and deleted.

FIG. 2 is an explanatory diagram of the measurement range of the short-range laser device 12 and the long-range laser device 14.
The short-range laser device 12 and the long-range laser device 14 are preferably laser range finders (LRF). The principle of distance measurement by the laser range finder is based on a time-of-flight method that measures the time difference from the projection of incident laser light to the reception of reflected light.
The short-range laser device 12 and the long-range laser device 14 use one or a plurality of laser light sources, and irradiate laser light in a preset range by a combination of horizontal line scan or vertical frame scan.

The short distance laser device 12 irradiates the short distance range A1 close to the traveling vehicle 1 with the first laser light L1 (see FIG. 3), and the obstacle position 5a shown in FIG. 4A from the time difference between the incident light and the reflected light. And the road surface position 6 are detected.
In this example, the short distance range A1 is a sector area surrounded by the arc ab and the arc cd.

The long-distance laser device 14 irradiates the overlapping range B overlapping the short-distance range A1 and the long-distance range A2 farther than the short-distance range A1 with the second laser light L2 (see FIG. 3), and the incident light. The obstacle position 5b shown in FIG. 4B is detected from the time difference between the reflected light and the reflected light.
In this example, the long distance range A2 is a fan-shaped region surrounded by the arc ef and the arc gh. The overlapping range B is a hatched range in this example, and is a sector region surrounded by the arc gh and the arc ij.
Each sector region includes a predetermined angular range (for example, 30 degrees or more) on the left and right with respect to the traveling direction 1a of the traveling vehicle 1. The angular ranges of the sector regions do not have to match.

  3A and 3B are explanatory views of the obstacle detection means of the short-range laser device 12 and the long-range laser device 14. FIG. 3A shows the case of the short-range laser device 12 and FIG. 3B shows the case of the long-range laser device 14. Show.

In FIG. 3A, the short-range laser device 12 irradiates the first laser beam L1 forward at a first angle θ1 that is obliquely downward. The first angle θ1 is an angle range in which the road surface position 6 and the obstacle position 5a shown in FIG. 4A can be detected from the time difference between the incident light and the reflected light of the first laser light L1. The angle range of the first angle θ1 is, for example, 2 degrees or more and 60 degrees or less, and preferably 3 degrees or more.
In this case, the road surface position 6 is determined when the difference in height between the two measurement points 4A and 4B is less than a predetermined threshold value, and the obstacle position 5a is determined when the difference is greater than or equal to the threshold value. This threshold value is set to a height that does not hinder the traveling of the traveling vehicle 1 (for example, 5 to 20 cm).

In FIG. 3B, the long-distance laser device 14 irradiates the second laser light L2 forward at a second angle θ2 that is obliquely downward. The second angle θ2 is an angle range in which the reflected light from the road surface 3 cannot be detected. The angle range of the second angle θ2 is, for example, not less than 0 degrees and not more than 3 degrees, preferably not more than 2 degrees.
In this case, the measurement point becomes far away, and the incident angle of the second laser light L2 becomes shallow, so that reflection from the road surface 3 is not measured. In such remote measurement, when the reflected light is measured from the measurement point 4C, it is determined as the obstacle position 5b.
However, the long-distance laser device 14 may detect the reflected light and erroneously detect it as the obstacle position 5b when a highly reflective object such as a white line lane is drawn on the road surface.

4A is an example of a measurement result of the short-range laser device 12, and FIG. 4B is an example of a measurement result of the long-range laser device 14. FIG. 4C is a schematic diagram of a real environment.
4A and 4B, the horizontal axis is the position in the width direction, the vertical axis is the position in the front direction, and the numbers in the drawings mean distance (m). The traveling vehicle 1 is located at a position where the width direction position is 0 m and the front direction position is 0 m.

  In FIG. 4A, the irradiation range of the first laser beam L1 by the short distance laser device 12, that is, the short distance range A1, is a fan-shaped range of about 10 m to 30 m. In this figure, ■ is an obstacle position 5a, and □ is a road surface position 6.

In FIG. 4B, the overlapping range B of the irradiation range of the second laser beam L2 by the long-range laser device 14 is a fan-shaped range of about 20 m to 30 m. The long distance range A2 is a fan-shaped range of about 30 m to 80 m. Moreover, in this figure, ■ is an obstacle position 5b.
Note that FIG. 4B includes an obstacle position 5c in which the white line lane on the road surface is erroneously detected as the obstacle position 5b.

  In FIG. 4C, the white line 11 is provided in the center of the road surface 3 and its both sides. The obstacle 4 is, for example, a pylon, and is disposed on the white lines 11 on both sides with a space therebetween.

FIG. 5 is a flowchart of the obstacle detection method of the present invention. In this figure, (A) is an overall flowchart, (B) is a partial flowchart of step S4, and (C) is a detailed flowchart of step S4-4.
FIG. 6 is an explanatory diagram of the obstacle detection method of the present invention. In this figure, (A) is a local environment map 7 by the short-range laser device 12, and (B) is a local environment map 8 by the long-range laser device 14. Further, (C) is a diagram showing the disagreement position 9, (D) is a diagram showing the white line position 9a and the target position 9b, and (E) is a local environment map in which the erroneously detected obstacle position 5c is deleted.
Hereinafter, the obstacle detection method of the present invention will be described by comparing FIG. 5 and FIG.

  In FIG. 5 (A), the obstacle detection method of the present invention includes steps (steps) S1 to S4.

  In step S1, the short distance laser device 12, the long distance laser device 14, and the data processing device 16 described above are prepared.

In step S2, the short distance laser device 12 irradiates the short distance range A1 close to the traveling vehicle 1 with the first laser light L1, and determines the obstacle position 5a and the road surface position 6 from the time difference between the incident light and the reflected light. To detect.
In step S3, the long-range laser device 14 irradiates the overlapping range B overlapping the short-range range A1 and the long-range range A2 farther than the short-range range A1 with the second laser light L2, and the incident light and The obstacle position 5b is detected from the time difference of the reflected light. The obstacle position 5b includes an erroneously detected obstacle position 5c.

In step S4, using the detection result in the overlapping range B, the data processing device 16 makes a false detection from the road surface position 6 and the obstacle positions 5a and 5b detected by the short distance laser device 12 and the long distance laser device 14. The detected obstacle position 5c is specified and deleted.
By step S4, a local environment map in which the erroneously detected obstacle position 5c in FIG. 6 (E) is deleted from the local environment map 7 in FIG. 6 (A) and the local environment map 8 in FIG. 6 (B) is created. .

  In FIG. 5 (B), step S4 consists of each step (process) of S4-1 to S4-4.

In step S4-1, local environment maps 7 and 8 in front of the traveling vehicle are created from the road surface position 6 and obstacle positions 5a and 5b detected by the short distance laser device 12 and the long distance laser device 14.
The local environment map 7 in FIG. 6A is created from the detection data of the short-range laser device 12, and the local environment map 8 in FIG. 6B is created from the detection data of the long-range laser device 14. The ranges of the local environment maps 7 and 8 are preferably common in a predetermined angle range (for example, 30 degrees or more) to the left and right with respect to the traveling direction 1a of the traveling vehicle 1.

In step S4-2, the detected obstacle positions 5a and 5b in the local environment maps 7 and 8 are compared.
In step S4-3, the mismatch position 9 between the obstacle positions 5a and 5b is extracted. FIG. 6C shows a mismatch position 9 extracted by synthesizing the local environment maps 7 and 8.
The obstacle position 5b (detected by the long-range laser device 14) in the overlapping range B is the mismatch position 9 when there is no obstacle position 5a (detected by the short-range laser device 12) at the same position. In addition, the obstacle positions 5a and 5b in the short distance range A1 and the long distance range A2 that do not overlap each other are always the mismatch positions 9.

  In step S4-4, the obstacle position 5c erroneously detected from the mismatch position 9 is detected and deleted.

In FIG. 5C, step S4-4 includes steps (processes) T1 to T3.
In step T1, as shown in FIG. 6D, the position on the straight line among the mismatch positions 9 in the overlapping range B is detected as the white line position 9a.
In step T2, the obstacle position 5b located on the extension line of the white line position 9a is extracted as the target position 9b among the mismatch positions 9 detected by the long-range laser device 14.
In step T3, when the distance from the traveling vehicle 1 of the target position 9b is equal to or greater than the first threshold, the number of detections is equal to or greater than the second threshold, and the detection width is equal to or smaller than the third threshold, the target position 9b is erroneously detected. The obstacle position 5c is determined, and the obstacle position 5c is deleted from the local environment maps 7 and 8. Each threshold is arbitrarily set in advance.

  That is, using the data of the obstacle position 5b detected in the overlapping range B and the data of the obstacle position 5a detected by the short-range laser device 12, the mismatch position 9 in the overlapping range B is obtained, and the mismatch position Using the information 9 and the above-described conditions, the obstacle position 5c erroneously detected by the long-range laser device 14 is specified and deleted from the local environment maps 7 and 8.

The white line (center line) has the following characteristics.
(1) Since the irradiation angle of the long-distance laser device 14 is shallow, it is not detected far away. This feature is used for the distance from the traveling vehicle 1 that is the first threshold.
(2) Since the measurement is performed like noise, the detected positions are irregular. This feature is used for the number of detections that is the second threshold.
(3) The width is about 10 cm. This feature is used for the width that is the third threshold value.

  According to the above-described apparatus and method of the present invention, the data processing device 16 uses the detection result in the overlapping range B to detect the road surface position 6 and the obstacle detected by the short-range laser device 12 and the long-range laser device 14. The obstacle position 5c erroneously detected from the object positions 5a and 5b is specified and deleted. Accordingly, even when a highly reflective object (for example, a white line) is drawn on the road surface at a long distance (for example, 30 m or more) from the traveling vehicle 1, the long distance obstacle 4 can be detected without erroneous detection. .

  Note that the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the gist of the present invention.

A1 short range, A2 long range, B overlap range,
H1, H2 installation height, L1 first laser beam, L2 second laser beam,
θ1 first angle, θ2 second angle, 1 traveling vehicle (moving body), 1a traveling direction,
2 earth removal equipment, 3 road surface, 4 obstacles, 4A, 4B, 4C measuring points,
5, 5a, 5b, 5c Obstacle position, 6 Road surface position,
7, 8 Local environment map, 9 Disagreement position, 9a White line position, 9b Target position,
10 Obstacle detection device, 11 White line,
12 Short range laser device (laser range finder),
14 Long-distance laser device (laser range finder),
16 Data processing device

Claims (4)

A short-range laser device and a long-range laser device mounted on a traveling vehicle traveling on a road surface;
A data processing device for detecting an obstacle position,
The short distance laser device irradiates a first laser beam on a short distance range close to the traveling vehicle, detects the obstacle position and the road surface position from the time difference between the incident light and the reflected light,
The long-distance laser device irradiates a second laser beam to an overlapping range that overlaps the short-distance range and a long-distance range that is farther than the short-distance range, and the failure is determined based on a time difference between the incident light and reflected light. Detect the object position,
The data processing device creates a local environment map ahead of the traveling vehicle using the detection result in the overlapping range, and the obstacle position mismatch detected by the short-range laser device and the long-range laser device. Extract the position,
In the overlapping range, the non-coincidence position that is located on a straight line is detected as a white line position,
Of the unmatched positions detected by the long-range laser device, extract the obstacle position located on an extension line of the white line position as a target position,
The obstacle in which the target position is erroneously detected when the distance of the target position from the traveling vehicle is equal to or greater than a first threshold, the number of detections is equal to or greater than a second threshold, and the detection width is equal to or smaller than a third threshold. Judging the position,
An obstacle detection apparatus, wherein the obstacle position is erased from the local environment map . The near laser device, the first laser beam is irradiated forward at a first angle oblique downward, the first angle, with a detectable angle range and the obstacle position and the road surface position from the time difference Yes,
The long-distance laser device irradiates the second laser beam forward at an obliquely downward second angle, and the second angle is an angle range in which reflected light from the road surface cannot be detected. The obstacle detection apparatus according to claim 1. The angle range of the first angle θ1 is not less than 2 degrees and not more than 60 degrees,
The obstacle detection apparatus according to claim 2, wherein an angle range of the second angle θ2 is greater than 0 degrees and equal to or less than 3 degrees. (A) Prepare a short-range laser device, a long-range laser device, and a data processing device,
(B) The short-range laser device irradiates a first laser beam to a short-range range close to the traveling vehicle, detects an obstacle position and a road surface position from a time difference between the incident light and the reflected light,
(C) By the long-distance laser device, the overlapping range overlapping the short-distance range and the long-distance range far from the short-distance range are irradiated with the second laser light, and the time difference between the incident light and the reflected light detecting said obstacle position from
(D) By using the detection result in the overlapping range by the data processing device,
(D1) Create a local environment map ahead of the traveling vehicle from the road surface position and the obstacle position detected by the short-range laser device and the long-range laser device,
(D2) Compare each detected obstacle position in the local environment map;
(D3) Extracting the inconsistent position of the obstacle position by the comparison,
(E1) Among the disagreement positions, those located on a straight line in the overlapping range are detected as white line positions,
(E2) Among the mismatched positions, the obstacle position located on an extension line of the white line position in the long distance range is extracted as a target position,
(E3) The target position is erroneously detected when the distance from the traveling vehicle of the target position is greater than or equal to the first threshold, the number of detections is greater than or equal to the second threshold, and the detection width is less than or equal to the third threshold. An obstacle detection method comprising: determining an obstacle position, and erasing the obstacle position from the local environment map .

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