JP7138538B2 - Laser scanner calibration method, material handling machine - Google Patents

Description

The present invention relates to a technique for calibrating the attitude of a laser scanner mounted on a transportation machine such as a mining dump truck.

In mining work in mines, there is a demand for technology for unmanned machines to perform mining work for the purpose of improving safety and reducing costs. Among the mining operations, in open pit mining, the earth and sand are excavated at the deepest part, and the earth and sand are excavated at the deepest part, and the earth and sand are dumped outside the excavation site. must be transported.

The work of transporting earth and sand outside the mining site is carried out by dump trucks and other large vehicles with a large earth and sand load capacity. It is necessary to transport soil while maintaining the

In order to transport the earth and sand to the outside of the mining site with high efficiency, it is necessary for multiple vehicles to make many round trips on the transportation road. In addition, as a countermeasure against falls from cliffs, it is important to detect road shoulders made of embankment on the edge of the road and prevent them from deviating from the road.

A dumping site for discharging the earth and sand transported to the outside of the mining site may be set under a predetermined cliff within the mining area. At this time, a wheel chock is installed by an embankment or the like in front of the cliff, and the dump truck must travel backwards against the wheel chock and stop in front of the embankment.

In this way, dump trucks are required to detect embankments existing on the sides and rear of the vehicle body and accurately measure their positions, and it is important to calibrate the installation posture of the laser scanner.

For example, Patent Literature 1 discloses a technique for adjusting the detection axis of an external recognition sensor without using the axle as a reference.

JP 2017-161467 A

The technology disclosed in Patent Document 1 only targets the deviation angle between the traveling direction of the vehicle body and the detection direction of the sensor, and does not target the three-dimensional posture of the sensor such as the pitch angle.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a technique capable of accurately calibrating a laser scanner.

In order to solve the above-mentioned problems, the laser scanner calibration method of the present invention includes two front laser scanners, each of which is a right front laser scanner and a left front laser scanner, which are provided on the left and right sides of the front of a transporting machine, respectively; The postures of two side laser scanners consisting of a right side laser scanner and a left side laser scanner provided on the left and right sides of the transport machine are calibrated based on the vehicle body coordinate system for defining the posture of the transport machine. a laser scanner calibration method using a calibration device, wherein the intersection of the laser line of the right side laser scanner on a flat road surface and the laser line of the right front laser scanner on the flat road surface is a first intersection, a second intersection of the laser line of the right front laser scanner and the laser line of the left front laser scanner on a flat surface, and a second intersection of the laser line of the left front laser scanner and the A landmark, which is a reflector, is placed at each position of the third intersection, which is the intersection of the left side laser scanner with the laser line on the flat road surface, and the calibration device performs scanning of each laser scanner. The position of each landmark in each laser scanner coordinate system that defines the attitude of each laser scanner based on the read light amount difference between the reflected light of the landmark and the reflected light of the flat road surface, calculating the positions of the first intersection point, the second intersection point, and the third intersection point in the vehicle body coordinate system based on the positions of the landmarks in the laser scanner coordinate system; Based on the positions of the first intersection point, the second intersection point, and the third intersection point in the Based on the positions of the first intersection point, the second intersection point, and the third intersection point in the vehicle body coordinate system, a value indicating the current three-dimensional posture of the right side laser scanner and the left side laser scanner in the vehicle body coordinate system is calculated. characterized in that

According to the present invention, highly accurate data for calibrating the attitude of the laser scanners can be obtained when detecting an obstacle by combining a plurality of laser scanners.
Problems, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

1 is a schematic diagram showing a configuration example of an autonomous driving system according to an embodiment; FIG. It is a schematic perspective view showing the arrangement of laser scanners in a dump truck. It is a schematic diagram which shows a car stop detection. It is a schematic diagram which shows a road-shoulder detection. It is a figure which illustrates a vehicle body coordinate system and a laser scanner coordinate system. It is a figure which illustrates a vehicle body coordinate system and a laser scanner coordinate system, and is a figure which illustrates the detail of a laser scanner coordinate system. 1 is a block diagram showing a configuration example of a calibration device according to a first embodiment; FIG. 4 is a flowchart showing processing by the calibration device of the first embodiment; FIG. 4 is a diagram showing an example of arrangement of landmarks; It is a figure explaining the method of calculating|requiring the installation position of the landmark of embodiment. It is a figure explaining the method of calculating|requiring the installation position of a landmark using the wheel type mobile body of embodiment. It is a figure explaining the method of calculating|requiring the installation position of a landmark using the flying object of embodiment. FIG. 10 is a diagram illustrating a method of obtaining landmark positions from detection values of the laser scanner according to the embodiment; It is a figure explaining the process which calculates the position of the landmark in the vehicle body coordinate system of embodiment. It is a figure explaining the process which calculates the position of the landmark in the vehicle body coordinate system of embodiment. It is a figure explaining the process which calculates the position of the landmark in the vehicle body coordinate system of embodiment. FIG. 7 is a diagram illustrating processing for calculating the orientation of the front laser scanner according to the embodiment; It is a figure explaining the process which calculates the attitude|position of the side surface laser scanner of embodiment. It is a figure explaining the process which calculates the attitude|position of the side surface laser scanner of embodiment. It is a figure explaining the method of calculating|requiring the rotation matrix for calibrating the laser scanner of embodiment. It is a figure explaining the method of calculating|requiring the rotation matrix for calibrating the laser scanner of embodiment. It is a figure explaining the method of calculating|requiring the rotation matrix for calibrating the laser scanner of embodiment. It is a figure explaining the method of calculating|requiring the rotation matrix for calibrating the laser scanner of embodiment. It is a block diagram which shows the structural example of the calibration apparatus of 2nd Embodiment. 9 is a flowchart showing processing by the calibration device of the second embodiment; It is a figure explaining the aspect which determines the flatness of the road surface of 2nd Embodiment. It is a figure which shows each member which comprises the landmark of 3rd Embodiment. FIG. 11 is a diagram illustrating landmarks of the third embodiment; It is a figure explaining the aspect using the landmark of 3rd Embodiment. It is a figure explaining the aspect using the landmark of 3rd Embodiment. FIG. 11 is a diagram illustrating values when a laser scanner reads the landmarks of the third embodiment; It is a figure which shows the hardware structural example of the calibration apparatus of embodiment.

The following embodiments will be divided into multiple sections or embodiments when necessary for convenience. In the following embodiments, when referring to the number of elements, etc. (including the number, numerical value, amount, range, etc.), unless otherwise specified or clearly limited to a specific number in principle, The number is not limited to a specific number, and may be greater than or less than a specific number. In the following embodiments, the constituent elements (including processing steps and the like) are not necessarily essential, unless otherwise specified or clearly considered essential in principle.

Hereinafter, a method for calibrating a laser scanner and a transportation machine according to an embodiment will be described with reference to drawings and the like. The following description shows specific examples of the content of the present invention, and the present invention is not limited to these descriptions, and various modifications by those skilled in the art within the scope of the technical idea disclosed in the present embodiment. Changes and modifications are possible. Further, in all the drawings for explaining the present embodiment, the same reference numerals are assigned to those having the same functions, and repeated explanations thereof may be omitted.

(First embodiment)
FIG. 1 shows a configuration example of an autonomous driving system according to an embodiment. The autonomous driving system 1 includes an unmanned transporting machine (hereinafter referred to as a dump truck) 100 and a traffic control system 200, which can transmit and receive data to and from each other through wireless communication. The autonomous driving system 1 also has a landmark installation position specifying device 60 that is used when installing the landmark 50 on the road surface. How to use the landmark installation position specifying device 60 will be described later. Although one dump truck 100 and one landmark installation position specifying device 60 are shown in FIG. Alternatively, the dump truck 100 may be a transport machine that travels by being driven by an operator.

The traffic control system 200 is a system for transmitting route information for the dump truck 100 to autonomously travel to the dump truck 100, and is composed of one computer or a plurality of computers. The traffic control system 200 has a travel route generation unit 201, a communication device 202, a vehicle information storage unit 203, and a map information storage unit 204, which are pre-stored in a storage device by a computer processing unit. It is realized by executing the program

The travel route generation unit 201 generates a round-trip travel route between the loading site and the dumping site where the dump truck 100 autonomously travels, based on the map information in the map information storage unit 311 and the vehicle information in the vehicle information storage unit 314. generated by referring to The communication device 202 then transmits the generated route to the dump truck 100 . Conventional technology is used for the functions and operations provided by the traffic control system 200 .

The dump truck 100 has a surrounding environment recognition device 101 that measures the distance and direction from the position of the own vehicle to objects existing in the surroundings, and a self-position measurement device 102 that measures the position and orientation of the dump truck 100 . The dump truck 100 also has a communication device 104 that receives data from the traffic control system 200 . The dump truck 100 has a vehicle body motion control device 103 that changes the speed and steering angle of the dump truck 100 based on the data from the traffic control system 200 and on the surrounding conditions such as the width of the transport path and the presence of oncoming vehicles. have.

The surrounding environment recognition device 101 has laser scanners 2a and 2b, which are car stop detection devices, and laser scanners 3a, 3b, which are road shoulder detection devices. The laser scanners 2a, 2b, 3a, and 3b are, for example, LiDARs that project laser light in a fan shape and measure the distance and direction to an object from the reflected light from the object.

As shown in FIG. 2, one or a plurality of laser scanners 2a and 2b are installed on each of the left and right sides of the dump truck 100 in order to detect the distance to the car stop behind the dump truck 100. It is a lateral laser scanner. In this embodiment, the laser scanner installed on the left side of the dump truck 100 is called a laser scanner 2a (left side laser scanner), and the laser scanner installed on the right side is called a laser scanner 2b (right side laser scanner). do. The laser scanners 3 a and 3 b are laser scanners for detecting the position of a part of the road shoulder on the side of the dump truck 100 . The laser scanners 3a and 3b are front laser scanners, which are installed one or a plurality of them on the front left and right sides of the dump truck 100, respectively. In this embodiment, the laser scanner installed on the front left side of the dump truck 100 is called a laser scanner 3a (left front laser scanner), and the laser scanner installed on the front right side is called a laser scanner 3b (right front laser scanner). do.

The surrounding environment recognition device 101 has a surrounding object relative position measuring device 4 , a surrounding environment storage device 5 and a calibration device 105 . The surrounding object relative position measuring device 4 measures the distance and direction from the dump truck 100 to the car stop and the road shoulder based on the values indicating the positions of the surrounding objects measured by the laser scanners 2a, 2b, 3a, and 3b. Find the distance and direction of The surrounding environment storage device 5 stores the coordinate values of the car stop and the road shoulder in the site coordinate system with the reference point provided in the site as the origin.

The calibration device 105 is a device that calculates numerical data in order to calibrate the postures of the laser scanners 2a, 2b, 3a, and 3b so that they are normal postures. Used in conjunction with locating device 60 . The calibration device 105 utilizes the road surface estimation processing result used for measurement by the surrounding object relative position measuring device 4 to estimate the current installation postures of the laser scanners 2a, 2b, 3a, and 3b. It has an estimating device 6 . The calibration device 105 also has a calibration value recording device 7 that records a calibration value (correction value) for establishing a normal posture. The calibration values obtained by the laser scanner attitude estimation device 6 are recorded in the calibration value recording device 7 .

The laser scanners 2a, 2b, 3a, and 3b are connected to a surrounding object relative position measuring device 4, and the surrounding object relative position measuring device 4 is connected to a surrounding environment storage device 5 and a laser scanner attitude estimation device 6. is doing. In addition, the laser scanner attitude estimation device 6 and the calibration value recording device 7 are connected, and the calibration value recording device 7 can use the values recorded in the calibration value recording device 7 in the surrounding object relative position measurement device 4. As shown, it is also connected to the surrounding object relative position measuring device 4 .

The self-position measurement device 102 has a wheel speed measurement unit 14 that measures the wheel rotation speed of the dump truck 100 and a steering angle measurement unit 15 that measures the steering angle. The self-position calculating device 17 of the self-position measuring device 102 calculates the speed and angular velocity of the dump truck 100 and the position and attitude in the site coordinate system from the measurement results of the wheel speed measuring unit 14 and the steering angle measuring unit 15. . The self-position of the dump truck 100 is corrected by the self-position correction device 16 in order to measure the position and attitude of the dump truck 100 with higher accuracy. The self-position correction device 16 is composed of an IMU (Inertial Measurement Unit), a GPS (Global Positioning System), or the like.

In the self-position measuring device 102 , the wheel speed measuring section 14 , the steering angle measuring section 15 and the self-position correcting device 16 are connected to the self-position calculating device 17 .

The vehicle body motion control device 103 has a braking device 18 that reduces or stops the speed of the dump truck 100 and a driving torque limiting device 19 that limits the rotational torque command value of the driving wheels of the dump truck 100 . The vehicle body motion control device 103 includes a steering control device 20 that changes the distance of the dump truck 100 from the road shoulder, and a map database that records information on the route and road width of the transportation route obtained from the traffic control system 200 and information on oncoming vehicles. 22. Further, the vehicle body motion control device 103 determines the speed and traveling direction of the dump truck 100 based on the information in the map database 22, etc. It has a transporting machine control device 21 that calculates 20 control variables.

In the vehicle body motion control device 103 , the transporting machine control device 21 inputs outputs from the map database 22 , the self-position calculation device 17 , and the surrounding object relative position measurement device 4 . The transporting machine control device 21 then outputs the calculation result to the braking device 18 , the driving torque limiting device 19 and the steering control device 20 .

The surrounding object relative position measurement device 4, the surrounding environment storage device 5, the laser scanner attitude estimation device 6, and the self-position measurement device 102 are, for example, microcomputer devices comprising a central processing unit, a storage device, an input/output circuit, and a communication circuit. . For the processing of the ambient environment storage device 5, a separate microcomputer device may be provided, or a single microcomputer device may be used. Further, the transporting machine control device 21 is, for example, an in-vehicle controller composed of a plurality of microcomputers, and realizes its functions by software inside the in-vehicle controller.

3 and 4 are diagrams schematically showing vehicle stop detection and road shoulder detection by the dump truck 100. FIG.

FIG. 3 shows how the dump truck 100 moves backward while detecting the bollard 31 . An arrow Di1 in FIG. 3 indicates the shortest distance from the center of the body of the dump truck 100 to the car stop. The arrow Di1 is obtained by inputting the values obtained from the laser scanners 2a and 2b into the surrounding object relative position measuring device 4 and performing calculations. Further, as shown in FIG. 3, in this embodiment, the direction perpendicular to the wheel stop 31 is used as a reference, and the direction of the vehicle body with respect to this direction is indicated by α1.

FIG. 4 shows how the dump truck 100 travels while detecting the embankment 32 on the transport path. Arrow Di2 in FIG. 4 indicates the shortest distance from the center of the body of dump truck 100 to the road shoulder. The arrow Di2 is obtained by inputting the values obtained from the laser scanners 3a and 3b to the surrounding object relative position measuring device 4 and calculating them. Also, α2 in FIG. 4 is the orientation of the vehicle body with respect to the extending direction of the road shoulder obtained based on the detection values of the laser scanners 3a and 3b.

5 and 6(a) are diagrams showing the vehicle body coordinate system and the laser scanner coordinate system, and FIG. 6(b) is a diagram for explaining the details of the laser scanner coordinate system. Here, ΣT shown in FIGS. 5 and 6A is a vehicle body coordinate system, with the center of the dump truck 100 as a reference point, the length direction of the vehicle body (advancing direction of the dump truck 100), the width direction, It is a coordinate system with the height direction as the reference axis. Σ2b and Σ3b shown in FIGS. 5 and 6A are the laser scanner coordinate systems of the laser scanner 2b and the laser scanner 3b, respectively. Although the laser scanner coordinate systems for the laser scanners 2a and 3a are not shown here, they are also defined as Σ2a and Σ3a.

FIG. 6B illustrates the laser scanner coordinate system Σ3b of the laser scanner 3b. The laser scanner coordinate system Σ3b has the center inside the housing of the laser scanner 3b as a reference point, and the scanning direction of the laser beam as the Y-axis. When the surface having the irradiation lens 300b, which is the laser irradiation port, is the front, the front direction of the laser scanner is the X axis of the laser scanner coordinate system Σ3b. The Z-axis of the laser scanner coordinate system Σ3b is defined as the normal direction of the plane formed by the Y-axis and the X-axis. The same definitions apply to the other laser scanner coordinate systems Σ2a, Σ2b, and Σ3a. Note that the X-axis of the laser scanner coordinate system can also be defined as a direction connecting the center position of the laser scanner and the center position CP that divides the scanning range into two, due to the configuration of the laser scanner.

When mounting a laser scanner on a vehicle body such as the dump truck 100, the position of the laser scanner (the reference position of Σ2a, Σ2b, Σ3a, and Σ3b with respect to ΣT) can be set with relatively high accuracy. On the other hand, the attitude of the laser scanner (rotation of .SIGMA.2a, .SIGMA.2b, .SIGMA.3a, .SIGMA.3b with respect to .SIGMA.T) is difficult to set with high accuracy, and needs to be corrected depending on the attitude of the actual installation. In addition, at a mine site where the vehicle travels on an unpaved road surface, the road surface is not in good condition, so the posture of the laser scanner gradually deviates from the normal posture due to vibrations. The calibration device 105 of the present embodiment performs calibration processing so that the current attitude of the laser scanner in which there is a deviation is represented by the vehicle body coordinate system ΣT. By using the vehicle body coordinate system .SIGMA.T as a reference in this manner, it is possible to adjust the posture of each laser scanner so that it assumes a normal posture.

FIG. 7 is a diagram showing the internal configuration of the calibration device 105, and particularly a configuration example of the laser scanner attitude estimation device 6. As shown in FIG. The calibration device 105 has the laser scanner attitude estimation device 6 and the calibration value recording device 7 as described above. The laser scanner attitude estimation device 6 includes a laser scanner detection value acquisition unit 701, a landmark position identification unit 702 (intersection position identification unit), an intersection position calculation unit 703, a front laser scanner attitude calculation unit 704, and a side laser scanner attitude calculation unit 705. have

Processing according to the present embodiment will be described with reference to the flowchart of FIG. Here, steps S004 to S007 in FIG. 8 are processed by the laser scanner attitude estimation device 6, and the installation attitudes of the laser scanners 2a, 2b and the laser scanners 3a, 3b estimated there are recorded in the calibration value recording device 7. .

First, in step S001, the dump truck 100 is moved to a flat position so that the four laser scanners 2a, 2b, 3a, and 3b (indicated as LIDAR in the drawing) can scan the same road surface. Here, if the calibration implementation area of the destination is determined in advance, the traffic control system 200 issues an instruction to the dump truck 100, and the dump truck 100 uses the transport machine control device 21 to determine the calibration implementation area by itself. You can move to

Next, in step S002, the laser scanners 2a, 2b, 3a, and 3b irradiate the road surface with laser beams and start scanning.

In step S003, as shown in FIG. 9, the worker places landmarks at the intersections of the laser lines (intersection lines between the laser scan surface and the road surface) irradiated from the laser scanners 2a, 2b, 3a, and 3b. . Here, a landmark 51 is installed at the intersection of each laser line irradiated from the laser scanner 2b on the right side and the laser scanner 3b on the right front, and the landmark 51 is irradiated from the laser scanner 3b on the right front and the laser scanner 3a on the left front. A landmark 52 is placed at the intersection of each laser line. A landmark 53 is placed at the intersection of each laser line emitted from the left front laser scanner 3a and the left side laser scanner 2a.

The landmarks 51, 52, and 53 are reflectors, and are made of a retroreflecting material, which is a material that reflects a significant amount of light. That is, the landmarks 51, 52, and 53 are placed so that the scan result at each intersection has a significant value. The landmarks 51, 52, and 53 are approximately the same size as the light receiving surface of the laser light receiver, are thin sheet-like ones, and may be rectangular or circular in shape.

Here, the landmark installation position specifying device 60 for installing the landmarks 51, 52, 53 will be described with reference to FIG. As the landmark installation position specifying device 60, in this embodiment, a laser receiver used in laser surveying, laser marking, and the like is adopted. 10A and 10B are diagrams illustrating the manner of use of the landmark installation position specifying device 60. FIG. The landmark installation position specifying device 60 is a device that indicates with an arrow 64 on a display unit 63 whether the laser emitted from each laser scanner hits above or below a reference line 62 shown on a laser detection surface 61 . The worker traces the line of intersection (laser line) between the laser scan plane and the road surface while repeatedly causing the landmark installation position specifying device 60 to cross the laser scan plane near the road surface. This operation finds the intersection of the laser lines and places a landmark at that location.

Further, as shown in FIGS. 11A and 11B, the landmark installation position specifying device 60 or the like may be mounted on a wheeled mobile body 65. FIG. The wheel-type moving body 65 traces the laser beam leftward if the light receiving position is on the right side, and moves rightward if the laser light receiving position is on the left side, while changing the running direction and the angular velocity. For example, as shown in FIG. 11(b), when the wheel-shaped moving body 65 runs on the laser line L1 of the laser scanner 2b, the received light intensity reaches a high value when it reaches the intersection with the laser line L2 of the laser scanner 3b. show. By setting the landmark 51 with this position as the intersection point, the intersection point of the laser lines L1 and L2 irradiated on the road surface can be found.

Furthermore, as shown in FIG. 12, a camera 66A capable of photographing the wavelength range of the laser emitted from each laser scanner is mounted on the flying object 66, and the flying object 66 is flown above the dump truck 100. Each laser line L1, L2, L3, L4 can be detected. The flying object 66 may determine the position of the stronger intensity as the intersection point. The real-time video from the camera 66A mounted on the flying object 66 is transmitted to a terminal device such as a notebook PC carried by the worker and displayed on the screen. The worker arranges the landmarks 51, 52, 53 while confirming the position of the intersection on the projected image.

Returning to the description of the flowchart in FIG. Next, in step S<b>004 , the laser scanner detection value acquisition unit 701 of the laser scanner attitude estimation device 6 acquires the road surface detected by the four laser scanners 2 a, 2 b, 3 a, and 3 b via the surrounding object relative position measurement device 4 . Acquire measurement data (reflected light detection value). Then, the landmark position specifying unit 702 detects the landmarks placed at the intersections based on the difference in light intensity of the reflection intensity, and specifies the positions of the landmarks in the laser scanner coordinate system, that is, the positions of the intersections where the laser lines intersect. .

FIG. 13 shows how landmarks are detected by the laser scanner 3b. FIG. 13(a) shows the measured point group represented by the distance and angle data acquired by the laser scanner 3b, converted from polar coordinates to orthogonal coordinates (X _3b , Y _3b ), and plotted on the laser scanner coordinate system Σ3b. It is the figure which showed the result. FIG. 13(b) is a graph plotting the magnitude E of the reflected intensity of each of these point clouds against the _Y3b coordinate of Σ3b. Here, the landmark position specifying unit 702 determines that the positions at which the reflection intensities show locally large values 54 and 55 are the installation positions of the landmarks 51 and 52 . That is, the landmark position specifying unit 702 obtains coordinate values Y ₅₁ and Y ₅₂ on Y _3b indicating values 54 and 55 from FIG. 13(b). Then, the landmark position specifying unit 702 obtains coordinate values X ₅₁ and X ₅₂ corresponding to the coordinate values Y ₅₁ and Y ₅₂ from the relationship shown in FIG. 13(a). The landmark position specifying unit 702 converts the position coordinates (X ₅₁ , Y ₅₁ ) and (X ₅₂ , Y ₅₂ ) thus obtained to the positions of the landmarks 51 and 52 in the laser scanner coordinate system Σ3b, that is, the laser coordinates. Take as the intersection of lines. The landmark position specifying unit 702 also obtains other intersection points by the same method.

Returning to the description of the flowchart in FIG. In step S005, the intersection position calculator 703 of the laser scanner posture estimation device 6 calculates the position of each intersection in the vehicle body coordinate system. Processing of the intersection position calculation unit 703 will be described with reference to FIGS. 14, 15, and 16. FIG.

The intersection position calculator 703 calculates the positions of the landmarks 51, 52, and 53 in the laser scanner coordinate system and the installation positions of the laser scanners 2a, 2b, 3a, and 3b in the vehicle body coordinate system (the installation points are P2a and P2b, respectively). , P3a and P3b), vertex A (first intersection), vertex B (second intersection), and vertex C (third intersection) of a triangle T formed by straight lines connecting the landmarks shown in FIG. Calculate the position in the vehicle body coordinate system. In FIG. 14, the vertices A, B, and C of the triangle T are intersection points of laser lines emitted from the laser scanners 2a, 2b, 3a, and 3b.

There are several methods for calculating the positions of the vertices A, B, and C, and one example is shown below. First, the parameters to be obtained are the three-dimensional position coordinates of the vertices A, B, and C.

In FIG. 15(a), the following four equations are derived, where H _AB is the leg of the _{perpendicular} extending from P3b to straight line AB, and HBC is the leg of the perpendicular extending from _P3a to straight line _BC . where _hAB is the distance between P3b and straight line _AB , _hBC is the distance between P3a and straight line _BC , _rAB is the distance between vertex A and vertex B, _rBC is vertex B and is the distance between vertices C; β _A is the angle between the straight line AB and AP _3b , and β _B is the angle between the straight line BC and BP _3a .

Note that h _AB , r _AB , β _A can be geometrically calculated using the coordinates of A and B in the laser scanner coordinate system, as shown in FIG _{. BC} and β _B can also be obtained by the same method.

Next, in FIG. 16, if the legs of perpendiculars drawn from A, B, and C to straight lines P _2b P _3b , P _3b P _3a , and P _3a P _2a are P _A , P _B , and P _C , respectively, the following are derived.

Here, since the lengths of the line segments P _2b P _3b , P _3b P _3a and P _3a P _2a are design values, the lengths of the line segments AP _2b and AP _3b and the lengths of the line segments BP _3b and BP _3a The length of the line segments CP _3a and CP _2a can be obtained from the detection data of each laser scanner. Therefore, the triangles AP _2b P _3b , BP _3b P _3a , and CP _3a P _2a in FIG. 16 are triangles with three known sides, and the values of h _A , h _B , and h _C are derived by performing geometrical operations. be done.

From the above results, 10 equations could be derived for 9 unknowns (three-axis position coordinates of vertices A, B, and C). The intersection position calculation unit 703 obtains the coordinate positions of A, B, and C using the above formulas and, for example, the method of least squares. In addition, since P _2b , P _3b , P _3a , and P _2a can be represented by the position coordinates in the vehicle body coordinate system, the intersection position calculation unit 703 calculates the position coordinates of the vertices A, B, and C in the vehicle body coordinate system. can be asked for.

Returning to the description of the flowchart in FIG. Next, in step S006, the front laser scanner attitude calculation unit 704 of the laser scanner attitude estimation device 6 calculates the following from the positional relationship between the installation positions of the left and right laser scanners 3a and 3b on the front surface and the triangle T formed by the straight line connecting the intersection points. The three-dimensional postures of the left and right laser scanners 3a and 3b are calculated.

と表すことができる。ここで、ｒ_ＡＯは点Ａと点Ｏ_ｘ３ｂとの間の距離であり、図１７（ｂ）のように、レーザスキャナ座標系での点Ａの位置と、直線ＡＢのＸ_３ｂ軸切片の位置との間の距離から求めることができる。尚、図１７（ｂ）において、点Σ３ｂ（点Ｐ_３ｂの位置）と点Ａとの位置関係は、ステップＳ００５により既に求められている。また、レーザスキャナ座標系のＸ_３ｂ軸方向は、上記図６（ｂ）での説明のとおり、レーザスキャナがスキャンする走査範囲の中心としており、この中心位置は、レーザスキャナの製造段階などで既に決まっている（レーザスキャナの走査範囲（走査角度）が例えば１２０°と規定されている場合、走査開始から６０°走査した位置が中心位置であるなど）。このことから、当該中心での読み取り値が、点Σ３ｂ（点Ｐ_３ｂ）と点Ｏ_ｘ３ｂ（Ｘ_３ｂ軸と直線ＡＢとの交点）との距離を示すものとなる。以上により、レーザスキャナ座標系における点Ａおよび点Ｏ_ｘ３ｂの各位置が求められるため、点Ａと点Ｏ_ｘ３ｂとの距離を示すｒ_ＡＯを導出することも可能となる。 First, in FIG. 17A, the intersection of a straight line extending from _P3b in the _X3b axis direction of the laser scanner coordinate system and the straight line AB is assumed to be _Ox3b . Here, the position of O _x3b in the vehicle body coordinate system is obtained by taking the origin of the vehicle body coordinate system as O,

It can be expressed as. Here, _rAO is the distance between point A and point _Ox3b , and as shown in FIG. 17(b), the position of point A in the laser scanner coordinate system and the position of the _X3b can be obtained from the distance between In FIG. 17(b), the positional relationship between point _Σ3b (position of point P3b) and point A has already been obtained in step S005. Further, the _X3b axis direction of the laser scanner coordinate system is the center of the scanning range scanned by the laser scanner, as explained in FIG. It is fixed (if the scanning range (scanning angle) of the laser scanner is defined as 120°, for example, the center position is the position scanned by 60° from the start of scanning). Therefore, the read value at the center indicates the distance between the point Σ3b (point P _3b ) and the point O _x3b (the intersection of the X _3b axis and the straight line AB). Since each position of the point A and the point _Ox3b in the laser scanner coordinate system is obtained by the above, it is also possible to derive _rAO indicating the distance between the point A and the point _Ox3b .

ここで、ｒ_ＣＯは、上記同様に、レーザスキャナ座標系での頂点Ｃの位置と、直線ＢＣのＸ_３ａ軸切片の位置との間の距離から求めることができる。 In FIG. 17(a), if the intersection of the straight line extending from P3a in the _X3b axis direction of the laser scanner coordinate system and the straight line BC is _Ox3a , the position of _Ox3a with _respect to the origin O of the vehicle body coordinate system (vehicle body coordinate system) is as follows by the same method as above.

Here, _rCO can be obtained from the distance between the position of the vertex C in the laser scanner coordinate system and the position of the _X3a -axis intercept of the straight line BC in the same manner as described above.

By performing calculations using the above method, the front laser scanner attitude calculation unit 704 can calculate the points O _x3b and O _x3a in the vehicle body coordinate system, and the current orientation of the laser scanner ( X-axis) can be expressed in the vehicle body coordinate system.

ここで、点Ｐ_３ｂ、点Ｐ_３ａ、点Ａ、点Ｂ、点Ｃは、いずれも車体座標系で表されるため、法線ベクトルｎ_３ｂ、ｎ_３ａも、車体座標系で表される。 Let n _3b be the normal vector of the scan plane (the plane formed by point P _3b , point A, and point B in FIG. 17(a)) irradiated by the laser scanner 3b. Let n _3a be the normal vector of the scan plane irradiated by the laser scanner 3a (the plane formed by points P _3a , B, and C in FIG. 17(a)). In this case, normal vectors n _3b and n _3a are as follows.

Here, since the point P _3b , the point P _3a , the point A, the point B, and the point C are all expressed in the vehicle body coordinate system, the normal vectors n _3b and n _3a are also expressed in the vehicle body coordinate system.

In this way, the front laser scanner attitude calculation unit 704 can calculate the current front direction (X-axis) of the laser scanner in the vehicle body coordinate system and the current scan plane direction (normal vector). Therefore, the front laser scanner posture calculation unit 704 can obtain the current three-dimensional postures of the left and right front laser scanners 3b and 3a in the vehicle body coordinate system.

Returning to the description of FIG. In step S007, the side laser scanner posture calculation unit 705 of the laser scanner posture estimation device 6 uses the fact that the triangle T is on the road surface to calculate the line of intersection between the scan planes of the left and right side laser scanners 2b and 2a and the road surface. A straight line AH _A and a straight line CH _C shown in FIGS. 18A and 18B are calculated. Here, H _A and H _C are legs of perpendiculars drawn from P _2b and P _2a to respective laser lines (lines indicated by straight lines AH _A and CH _C in FIG. 18).

で表すことができる。ここで、上記の方程式は、ｘ成分、ｙ成分、ｚ成分で示されるベクトルであるため、計６つの方程式が得られたことになる。 At this time, since the straight lines AH _A and CH _C are straight lines on the plane formed by the triangle T (ABC), using four parameters m _A , m _C , n _A , and n _C ,

can be expressed as Here, since the above equations are vectors represented by x, y, and z components, a total of six equations are obtained.

Further, the distance h _2b between P _2b and straight line AH _A , the distance h _2a between P _2a and straight line CH _C , the angle α _A between straight line AH _A and straight line AP _2b , and straight line CH _C and straight line Using the angle α _C with CP _2a , the following four equations can be obtained. Note that h _2b , h _2a , α _A , and α _C can be obtained based on measured values of a laser scanner.

From the above results, ten equations could be obtained for ten unknowns (positional coordinates of H _A and H _C and four unknown parameters m _A , m _C , n _A and n _C ). The side laser scanner attitude calculation unit 705 obtains the position coordinates of H _A and H _C as solutions of the simultaneous equations. Moreover, since each of the above formulas is represented by position coordinates in the vehicle body coordinate system, H _A and H _C can also be represented in the vehicle body coordinate system.

と求めることができる。ここで、ｓ_ＡＯは、図１９（ｂ）のように、レーザスキャナ座標系での頂点Ａの位置と、直線ＡＨ_ＡのＸ_２ｂ軸切片の位置との間の距離から求めることができる（図１７と同様の手法となる）。 Next, in step S007, the side laser scanner posture calculation unit 705 determines that the line of intersection between the scan planes of the laser scanners 2a and 2b on the left and right sides and the road surface is on the plane formed by the triangle T formed by the straight lines connecting the landmarks. The three-dimensional postures of the laser scanners 2a and 2b on the left and right sides are calculated so as to do so. In FIG. 19A, the intersection of a straight line extending from P _2b in the X _2b axis direction of the laser scanner coordinate system and the laser scanner 2b (straight line AH _A ) is assumed to be O _x2b . Here, the position of O _x2b in the vehicle body coordinate system is obtained by taking the origin of the vehicle body coordinate system as O,

can be asked. Here, s _AO can be obtained from the distance between the position of the vertex A in the laser scanner coordinate system and the position of the X _2b axis intercept of the straight line AH _A , as shown in FIG. 17).

Similarly, the position of _Ox2a in the vehicle body coordinate system can be determined by the following, with O being the origin of the vehicle body coordinate system.

By performing calculations using the above method, the side laser scanner attitude calculation unit 705 can calculate the points O _x2b and O _x2a in the vehicle body coordinate system, and the current orientation of the laser scanner ( A vector indicating the direction of the X axis) can be expressed in the vehicle body coordinate system.

ここで、点Ｐ_２ｂ、点Ｐ_２ａ、点Ａ、点Ｂ、点Ｈ_Ａ、点Ｈ_Ｃは、いずれも車体座標系で表されるため、法線ベクトルｎ_２ｂ、ｎ_２ａも、車体座標系で表される。 Let n _2b be the normal vector of the scan plane irradiated by the laser scanner 2b (the plane formed by point P _2b , point _A , and point HA in FIG. 19(a)). Let n _2a be the normal vector of the scan plane irradiated by the laser scanner 2a (the plane formed by points P _2a , _C , and H 2 C in FIG. 19(a)). In this case, normal vectors n _2b and n _2a are as follows.

Here, since the points P _2b , P _2a , A, B, H _A , and H _C are all expressed in the vehicle body coordinate system, the normal vectors n _2b and n _2a are also expressed in the vehicle body coordinate system. is represented by

In this way, the side laser scanner attitude calculation unit 705 calculates the current orientation of the laser scanner in the vehicle body coordinate system (vector indicating the direction of the X-axis) and the current orientation of the scan plane (normal vector). can be done. Therefore, the side laser scanner posture calculation unit 705 can obtain the current three-dimensional postures of the left and right side laser scanners 2b and 2a in the vehicle body coordinate system.

Vectors indicating the current attitudes of the laser scanners 2a, 2b, 3a, and 3b calculated by the front laser scanner attitude calculator 704 and the side laser scanner attitude calculator 705 are recorded in the calibration value recording device 7 as calibration data. It should be noted that the three-dimensional posture data is recorded as data in a three-dimensional coordinate system or data in a polar coordinate system.

In the following, a method for determining the amount of rotation for associating the current attitudes (laser scanner coordinate system _{Σ P} ) of the laser scanners 2a, 2b, 3a, and 3b thus obtained with the vehicle body coordinate system ΣT will be described. do.

In FIG. 20, the position of the laser scanner is P (x, y, z), the normal vector of the scan plane is n, the X coordinate axis (x _s ) of the laser scanner coordinate system Σ _P and the straight line formed by the measurement point group of the laser scanner Let O(x ₀ , y ₀ , z ₀ ) be the intersection with .

In addition, the _{foot P} '( _{x , y} , z ₀ ), and let H be the foot from P' to the straight line PO.

となり、図２１のようにレーザスキャナ座標系をそのｘ_ｓ軸まわりにθ_ｘ回転させる。ここで、回転後の新たな座標系を（ｘ_ｓ，ｙ’_ｓ，ｚ’_ｓ）とする。 Here, the amount of rotation of the laser scanner coordinate system _ΣP can be obtained from the amount of rotation when _ΣP is rotated so as to coincide with the vehicle body coordinate system _ΣT . First, assuming that the angle between the normal vector n and the straight line _P'H is θx,

Then, as shown in FIG. 21, the laser scanner coordinate system is rotated by _.theta.x around its xs _axis . Here, let the new coordinate system after rotation be (x _{s ,} y' _s , z' _s ).

となり、図２２のようにレーザスキャナ座標系をそのｙ’_ｓ軸まわりにθ_Ｙ回転させる。ここで、回転後の新たな座標系を（ｘ’_ｓ，ｙ’_ｓ，ｚ’’_ｓ）とする。 Next, assuming that the angle between the straight line PO and the straight line _P'O is θY,

As a result, the laser scanner coordinate system is rotated by _{θ Y} about its y's axis as shown in FIG. Here, let the new coordinate system after rotation be (x' _s , y' _s , z'' _s ).

となり、図２３のようにレーザスキャナ座標系をそのＺ’’_ｓ軸まわりにθ_Ｚ回転させる。ここで、回転後の新たな座標系を（ｘ’’_ｓ，ｙ’’_ｓ，ｚ’’_ｓ）とする。このとき、回転後のレーザスキャナ座標系（ｘ’’_ｓ，ｙ’’_ｓ，ｚ’’_ｓ）と車体座標系の姿勢が一致する。レーザスキャナの姿勢は、これらθ_Ｘ、θ_Ｙ、θ_Ｚで表すことができ、回転行列をＲ（θ）とすると、レーザスキャナで取得した計測点の座標（ｘ_ｓ，ｙ_ｓ）を車体座標系の座標（ｘ_Ｔ，ｙ_Ｔ，ｚ_Ｔ）に変換する式は、次式となる。

Finally, assuming that the angle between the straight line _P'O and the x _T -axis of the vehicle body coordinate system is θZ,

Then, as shown in FIG. 23, the laser scanner coordinate system is rotated by _.theta.Z around its _Z ''s axis. Here, let the new coordinate system after rotation be (x'_'s , y''s, _z '_'s ). At this time, the posture of the laser scanner coordinate system (x'_'s , y''s, _z ''s) after rotation _coincides with the vehicle body coordinate system. The attitude of the laser scanner can be represented by these θ _X , θ _Y , and θ _Z , and if the rotation matrix is R(θ), the coordinates (x _s , y _s ) of the measurement points acquired by the laser scanner are the vehicle body coordinates. The formula for conversion to system coordinates (x _T , y _T , z _T ) is the following formula.

By applying the above method to the laser scanners 2a, 2b, 3a, and 3b, the attitudes of the four laser scanners, that is, the laser scanner coordinate systems Σ2a and Σ2b of the laser scanners 2a, 2b, 3a, and 3b with respect to the vehicle body coordinate system ΣT. , .SIGMA.3a and .SIGMA.3b can be calculated.

20 to 23 may be performed by the front laser scanner attitude calculation unit 704 for the laser scanners 3a and 3b, and by the side laser scanner attitude calculation unit 705 for the laser scanners 2a and 2b. good. In this case, the obtained rotation matrices R(θ _x ), R(θ _y ) and R(θ _z ) are recorded in the calibration value recording device 7 as calibration data.

The calibration data recorded in the calibration value recording device 7 are displayed, for example, on a display device provided in the driver's seat of the dump truck 100 or transmitted to the traffic control system 200 . Ultimately, a correction suitable for each site is separately performed on this calibration data, such as by directing the laser scanner downward by a specified value. Each laser scanner is adjusted so as to have the orientation after the correction.

(Second embodiment)
In the first embodiment, the operator or the traffic control system 200 guides the dump truck 100 to a place assumed to be flat, thereby moving the dump truck 100 to a flat road surface. However, if the vehicle body is large, the area where the calibration is performed is correspondingly large, and it is difficult for the human eye to judge whether the road surface is flat or not. Therefore, as shown in FIG. 24, the laser scanner posture estimation device 6 of the second embodiment is provided with a road surface state identification unit 2501. FIG.

FIG. 25 is a flowchart including the operation of the road surface condition identifying section 2501, and FIG. 26 is a diagram for explaining the operation of the road surface condition identifying section 2501. FIG. In step S201, the road surface condition identification unit 2501 calculates a regression line L from each measurement point Q _i indicating the road surface shape measured by the four laser scanners 2a, 2b, 3a, and 3b (see FIG. 26).

Then, in step S202, the road surface condition identification unit 2501 obtains the residual σ _i of each measurement point Q _i with respect to the regression line L, and calculates the variance (sum of squares Σ _i σ _i ² ). The road surface condition identification unit 2501 determines whether this variance is less than a preset threshold value D _th (Σ _i σ _i ² <D _th ). If it is less than the threshold value D _th (S202: Yes), the road surface condition identification unit 2501 regards the location as suitable for performing calibration, and advances the process to step S203. The processing of steps S203 to S207 is the same as steps S003 to S007 of the first embodiment. On the other hand, if it is equal to or greater than the threshold value D _th (S202: No), the road surface condition identification unit 2501 outputs a warning command to the speaker indicating that the location is unsuitable for calibration, and the speaker emits a buzzer sound or the like. A warning is issued to notify this effect (S208).

By performing such checks and selecting the implementation location, it is possible to improve the accuracy of the calibration work in the post-process.

(Third Embodiment)
In the first and second embodiments described above, workers or drones examine the intersection positions of the laser lines irradiated onto the road surface from the laser scanners 2a, 2b, 3a, and 3b, and place the landmarks 50 at the intersections. Example embodiments have been described. In the third embodiment, a mode will be described in which the positions of the intersections can be calculated while further reducing the support work of workers and the like.

Landmarks used in the third embodiment are linear sheets 71 and 73 (linear members) composed of members 72a, 72b, 74a, and 74b having different laser reflectances, as shown in FIG. A circular sheet 75, which is a member having a different laser reflectance from the members 72a, 72b, 74a, and 74b, is used as the landmark used in the third embodiment. FIG. 28 is a diagram showing a landmark 70 created using these members. The circular sheet 75 of the landmark 70 forms the outline of the landmark, and the inner side thereof has a configuration in which linear sheets 71 and 73 are arranged in a lattice.

ここでθ_１の符号は、図２９（ｂ）において、円状シート７５の２つの検出点群の中心ｙ_ｃに対して、直線７１の検出点群の位置がどちらに寄っているかで判断できる。 Also, L1 (broken line) shown in FIG. 29A is assumed to be a laser line irradiated onto the road surface from one of the laser scanners. FIG. 29B shows a graph in which the laser line L1 is plotted on the horizontal axis ys and the laser reflection intensity corresponding to each spot light forming the laser line is plotted on the vertical axis. The laser line _L1 is expressed using _an inclination θ1 with respect to the xL axis of the landmark coordinate system and _a distance d1 from the origin of the landmark coordinate system. The inclination θ ₁ of the straight line L1 is obtained from the distance n ₁ between the straight lines 71 (=linear sheet 71) of the landmark 70 and the distance m ₁ between the members 74a forming the straight line 71 obtained from FIG. It can be obtained by the formula.

Here, the sign of θ ₁ can be judged by the position of the detection point group of the straight line 71 with respect to the center yc of the two detection point groups of the circular sheet 75 in _FIG . 29(b). .

Further, the distance _d1 is obtained by the following equation using the radius _D1 of the circular sheet 75 and the distance _t1 between the intersections of the circular sheet 75 and the laser line _L1 obtained from FIG. be able to.

ここで、ｎ_２はランドマーク７０の直線７１（＝直線状シート７１）の間隔、ｍ_２は直線７１を構成する部材７４ａまたは部材７４ｂの間隔である。また、Ｄ_２は円状シート７５の半径、ｔ_２は円状シート７５とレーザラインＬ_２との交点間の距離である。 A laser line (here, L2) irradiated onto the road surface from another laser scanner that intersects the laser line L1 can also be obtained by the method shown in FIG. That is, the inclination θ ₂ of the laser line _L2 with respect to the xL axis of the landmark coordinate system and the distance d ₂ from the origin of the landmark coordinate system to the laser line L2 are as follows.

Here, _n2 is the interval between the straight lines 71 (=linear sheets 71) of the landmarks 70, and _m2 is the interval between the members 74a or 74b forming the straight line 71. FIG. _D2 is the radius of the circular sheet 75, and _t2 is the distance between the intersections of the circular sheet 75 and the laser line _L2 .

Next, how to find the intersection of the laser lines L ₁ and L ₂ will be described with reference to FIG. 30 . 30 is a diagram in which the angle of the laser line L1 of FIG. 29 is changed. The intersection point C _c (x _cc , y _cc ) of the laser line L ₁ and the laser line L ₂ in the landmark coordinate system is obtained from the linear parameters θ ₁ , d ₁ , θ ₂ , d ₂ by the following equation. can ask.

最後に、図３１（ａ）、（ｂ）のように、円状シート７５に相当する反射強度の検出位置から、距離ｃ_１、ｃ_２離れた位置として、それぞれのレーザスキャナ座標系でのレーザラインＬ_１、Ｌ_２の交点Ｃ_ｃの位置を求めることができる。図３１（ａ）を例にして説明すると、レーザスキャナ姿勢推定装置６のランドマーク位置特定部７０２は、レーザスキャナによって走査されたレーザラインＬ_２上におけるレーザ反射率の高い位置Ｐ２の座標値を検出することができる。ランドマーク位置特定部７０２は、レーザラインＬ_２上においてこの交点Ｐ２から距離ｃ_２離れた位置を求めることで、交点を導出することができる。またランドマーク位置特定部７０２は、図３１（ｂ）に示すように、レーザラインＬ_１上におけるレーザ反射率の高い位置Ｐ１の座標値も、同様に検出することができ、Ｐ１の位置から距離ｃ_１離れた位置を交点とする。このようにして求めた２つの交点の位置が、仮に異なっている場合、ランドマーク位置特定部７０２は、これら交点の中間の位置を正規の交点の位置とする。 Furthermore, the distances c ₁ and _{c 2} from the intersection points P1 and P2 of the circular sheet 75 and the laser lines L ₁ and L ₂ to the point Cc can be obtained by the following equations.

Finally, as shown in FIGS. 31(a) and 31(b), from the reflection intensity detection position corresponding to the circular sheet 75, positions separated by distances c ₁ and c ₂ are set as laser beams in respective laser scanner coordinate systems. The position of the intersection point C _c of the lines L ₁ and L ₂ can be determined. Taking FIG. 31(a) as an example, the landmark position specifying unit 702 of the laser scanner attitude estimation device 6 calculates the coordinate values of the position P2 with the _high laser reflectance on the laser line L2 scanned by the laser scanner. can be detected. _The landmark position specifying unit 702 can derive the intersection point by finding a position _on the laser line L2 which is separated from the intersection point P2 by a distance c2. In addition, as shown in FIG. 31(b), the landmark position specifying unit 702 can similarly detect the coordinate values of the position P1 _on the laser line L1 where the laser reflectance is high. The point of intersection is set at a distance of ₁ c. If the positions of the two points of intersection obtained in this way are different, the landmark position specifying unit 702 sets the middle position of these points of intersection as the normal position of the point of intersection.

As described above, the position of the intersection point on the scanning plane of each laser scanner can be detected.

(Hardware configuration of calibration device)
Finally, a hardware configuration example of the calibration device 105 described in each of the above embodiments will be described with reference to FIG. The calibration device 105 has the same hardware configuration as a conventional computer, as shown in FIG.

A CPU 3201 (CPU: Central Processing Unit) is a processing device that expands a program stored in a ROM 3203 (ROM: Read Only Memory) or a storage 3204 into a RAM 3202 (RAM: Random Access Memory) and executes arithmetic operations. The CPU 3201 comprehensively controls each hardware inside the calibration device 105 by executing a program. A RAM 3202 is a volatile memory and a work memory for directly inputting/outputting data to/from the CPU 3201 . The RAM 3202 temporarily stores necessary data while the CPU 3201 is executing the program.

A ROM 3203 is a non-volatile memory and stores firmware executed by the CPU 3201 . A storage 3204 is an auxiliary storage device such as a flash memory, an SSD (Solid State Drive), or a hard disk drive. The storage 3204 non-volatilely stores programs to be executed by the CPU 3201 and control data such as parameters.

A connection I/F 3205 is a group of interfaces for connecting various peripheral devices, and is responsible for, for example, connection with the surrounding object relative position measuring device 4, connection with a display device, buzzer, and the like.

Although the calibration device 105 has such a configuration, part or all of it may be implemented by an integrated circuit such as ASIC. Even if part or all of it is implemented by an integrated circuit or the like, the configuration is regarded as one form of computer. Also, each block shown in FIGS. 7 and 24 is realized by the CPU 3201 executing a program.

In addition, the present invention is not limited to the above-described embodiment, and includes various modifications. For example, the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described. Also, part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Moreover, it is possible to add, delete, or replace part of the configuration of each embodiment with another configuration. Further, each of the configurations, functions, processing units, processing means, etc. described above may be realized by hardware, for example, by designing a part or all of them using an integrated circuit. Moreover, each of the above configurations, functions, etc. may be realized by software by a processor interpreting and executing a program for realizing each function. Information such as programs, tables, and files that implement each function can be stored in recording devices such as memories, hard disks, SSDs (Solid State Drives), or recording media such as IC cards, SD cards, and DVDs.

1: Autonomous running system 2a, 2b, 3a, 3b: Laser scanner 4: Surrounding object relative position measuring device 5: Surrounding environment storage device 6: Laser scanner posture estimating device 7: Calibration value recording device 14: Wheel speed measuring unit 15 : Steering angle measurement unit 16: self-position correction device 17: self-position calculation device 18: braking device 19: driving torque limiting device 20: steering control device 21: transporting machine control device 22: map database 50, 51, 52, 53: Landmark 60: Landmark installation position specifying device 61: Laser detection surface 62: Reference line 63: Display unit 64: Arrow 65: Wheel type moving body 66: Flying body 70: Landmarks 71, 73: Linear sheet 75: Circle Shape sheet 100: Dump truck 101: Surrounding environment recognition device 102: Self-position measurement device 103: Vehicle body motion control device 104: Communication device 105: Calibration device 200: Traffic control system 201: Travel route generation unit 202: Communication device 203: Vehicle information storage unit 204: map information storage unit 300b: irradiation lens 311: map information storage unit 314: vehicle information storage unit 701: laser scanner detection value acquisition unit 702: landmark position specifying unit 703: intersection position calculation unit 704: front surface Laser scanner attitude calculation unit 705: Side laser scanner attitude calculation unit 2501: Road surface condition identification unit

Claims (8)

Postures of two front laser scanners consisting of a right front laser scanner and a left front laser scanner respectively provided on the left and right sides of the front surface of the material handling machine, and right and left side laser scanners respectively provided on the left and right sides of the material handling machine. A method of calibrating a laser scanner using a calibration device for calibrating the postures of two side laser scanners, which are laser scanners, with reference to a vehicle body coordinate system for defining the posture of the transporting machine,
a first intersection point between the laser line of the right side laser scanner on a flat road surface and the laser line of the right front laser scanner on the flat road surface; the laser line of the right front laser scanner and the left front surface; at a second point of intersection, which is the point of intersection of the laser line of the laser scanner on the flat surface, and the point of intersection of the laser line of the left front laser scanner and the laser line of the left side laser scanner on the flat surface; Placing a landmark, which is a reflector, at each position of a certain third intersection,
The calibration device
Based on the light amount difference between the reflected light of the landmark and the reflected light of the flat road surface read by the scanning of each laser scanner, each laser scanner coordinate system defining the attitude of each laser scanner. Deriving the position of each landmark respectively,
calculating positions of the first intersection point, the second intersection point, and the third intersection point in the vehicle body coordinate system based on the positions of the landmarks in the laser scanner coordinate system;
Based on the positions of the first intersection point, the second intersection point, and the third intersection point in the vehicle body coordinate system, a value indicating the current three-dimensional posture of the right front laser scanner and the left front laser scanner in the vehicle body coordinate system is calculated. calculate,
Based on the positions of the first intersection point, the second intersection point, and the third intersection point in the vehicle body coordinate system, a value indicating the current three-dimensional posture of the right side laser scanner and the left side laser scanner in the vehicle body coordinate system is calculated. calculate,
A method of calibrating a laser scanner, characterized by: In the calibration method according to claim 1,
The current three-dimensional posture of each of the laser scanners is the normal to the vehicle body coordinate system of the laser scanner facing forward in the vehicle body coordinate system and the scan plane that forms the laser line by intersecting the flat road surface. indicated by the orientation and
A method of calibrating a laser scanner, characterized by: In the calibration method according to claim 1,
The calibration device
Calculating a regression line from the measurement point group indicating the shape of the road surface obtained by scanning the road surface with the laser scanner,
Calculate the residual of each measurement point with respect to the regression line for each measurement point,
Comparing the variance of the residual with a threshold, and issuing a warning command when the variance is greater than or equal to the threshold;
A method of calibrating a laser scanner, characterized by: In the calibration method according to claim 1,
When arranging the landmarks, the light receiver of the laser scanner traces along the laser line on the flat road surface based on the amount of light received, so that the first intersection point, the second intersection point, the third intersection point, and the third intersection point. identify the location of the intersection point,
A method of calibrating a laser scanner, characterized by: In the calibration method according to claim 4,
When arranging the landmarks, a laser line on the flat road surface is traced based on the amount of light received by the wheeled mobile body on which the light receiver is mounted. Identifying the location of the three intersections,
A method of calibrating a laser scanner, characterized by: In the calibration method according to claim 1,
When arranging the landmarks, a flying object equipped with a camera that captures the wavelength range of the laser emitted from each of the laser scanners is flown over the transportation machine, and based on the image from the camera, the second Identifying the positions of the first intersection, the second intersection, and the third intersection;
A method of calibrating a laser scanner, characterized by: In the calibration method according to claim 1,
The landmark is composed of a member having a different laser reflectance and forming an outline of the landmark, and a plurality of linear members forming a grid on the inner side thereof,
The calibration device
Positions of the first intersection point, the second intersection point, and the third intersection point in each laser scanner coordinate system based on the light amount difference of the reflected light from each member of the landmark read by the scanning of each of the laser scanners. respectively,
A method of calibrating a laser scanner, characterized by: a conveying machine,
two front laser scanners consisting of a right front laser scanner and a left front laser scanner respectively provided on the left and right sides of the front surface of the transport machine;
two side laser scanners comprising a right side laser scanner and a left side laser scanner respectively provided on both left and right sides of the transport machine;
a laser scanner calibration device that calibrates the attitude of each of the laser scanners with reference to a vehicle body coordinate system for defining the attitude of the transport machine;
The calibration device is
A laser scanner detection value acquisition unit that acquires detection values read by scanning by each laser scanner, the laser line on the flat road surface of the right side laser scanner and the laser on the flat road surface of the right front laser scanner a first intersection point that is the intersection point of the right front laser scanner and the laser line on the flat surface of the left front laser scanner; and a second intersection point that is the intersection point of the laser line of the right front laser scanner and the laser line on the left front laser scanner. a laser scanner detection value acquisition unit that acquires a reflected light detection value for the flat road surface at each position of a third intersection, which is an intersection point between the laser line and the laser line of the left side laser scanner on the flat road surface;
In each laser scanner coordinate system, which defines the attitude of each laser scanner, based on the light amount difference between the reflected light at the first intersection, the second intersection, and the third intersection and the reflected light from the flat road surface. an intersection position specifying unit that derives the positions of the first intersection, the second intersection, and the third intersection;
Based on the positions of the first intersection point, the second intersection point, and the third intersection point in each of the laser scanner coordinate systems, the positions of the first intersection point, the second intersection point, and the third intersection point in the vehicle body coordinate system are calculated. an intersection position calculator for
Based on the positions of the first intersection point, the second intersection point, and the third intersection point in the vehicle body coordinate system, a value indicating the current three-dimensional posture of the right front laser scanner and the left front laser scanner in the vehicle body coordinate system is calculated. a front laser scanner posture calculation unit for calculating;
Based on the positions of the first intersection point, the second intersection point, and the third intersection point in the vehicle body coordinate system, a value indicating the current three-dimensional posture of the right side laser scanner and the left side laser scanner in the vehicle body coordinate system is calculated. a side laser scanner posture calculation unit for calculating;
A transport machine characterized by having

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