Correction device and correction method

Abstract

A distance acquisition unit acquires first distance data of a range in which a first reference object provided at an arbitrary position outside the work machine exists, measured by a vehicle-mounted distance sensor. A position calculation unit calculates a position of the first reference object in a predetermined coordinate system based on the first distance data. A relationship acquisition unit acquires a positional relationship between the first reference object and a second reference object whose position in the coordinate system is known. A correction unit corrects a parameter for measuring a position in the coordinate system based on distance data of the vehicle-mounted distance sensor, based on the first distance data and the positional relationship.

Description

Technical Field

[0001] This disclosure relates to a calibration device and a calibration method for calibrating vehicle-mounted distance sensors installed on operating machinery.

[0002] This application claims priority based on Japanese Patent Application No. 2020-106401, filed on June 19, 2020, the contents of which are incorporated herein by reference. Background Technology

[0003] Patent Document 1 discloses a technique for calibrating a distance sensor in a work machine having a working device and a shooting device. Specifically, in the calibration system described in Patent Document 1, the distance sensor measures the distance to a target set on the working device, the positional relationship between the distance sensor and the target is determined based on an image, and the distance sensor is calibrated based on the posture of the working device and the positional relationship determined from the distance data.

[0004] Prior art literature

[0005] Patent documents

[0006] Patent Document 1: International Publication No. 2016 / 148309 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] However, the distance sensor on the working machine is not necessarily limited to being positioned facing the front of the machine. For example, there are cases where the distance sensor is located on the side of the machine. In this case, since the working device is not within the measurement range of the distance sensor, the calibration method disclosed in Patent Document 1 cannot be performed. Furthermore, not all working machines are limited to having a working device. In this case, the calibration method disclosed in Patent Document 1 also cannot be performed.

[0009] The purpose of this disclosure is to provide a calibration device and a calibration method that can calibrate a distance sensor regardless of whether the working device is within the measurement range of the distance sensor.

[0010] Methods for solving problems

[0011] According to one aspect of the present invention, the calibration device is a calibration device for calibrating an on-board distance sensor installed on a working machine, wherein the calibration device comprises: a distance acquisition unit that acquires first distance data, which is distance data of the range of a first reference object located at an arbitrary position outside the working machine as measured by the on-board distance sensor; a position calculation unit that calculates the position of the first reference object in a predetermined coordinate system based on the first distance data; a relationship acquisition unit that acquires the positional relationship between the first reference object and a second reference object whose position is known in the coordinate system; and a calibration unit that calibrates parameters used to measure the position in the coordinate system based on the distance data of the on-board distance sensor, based on the first distance data and the positional relationship.

[0012] Invention Effects

[0013] According to the above method, the calibration device can calibrate the distance sensor regardless of whether the working device is within the measurement range of the distance sensor. Attached Figure Description

[0014] Figure 1 This is a diagram showing an example of the posture of a working machine.

[0015] Figure 2 This is a schematic diagram showing the structure of the working machine according to the first embodiment.

[0016] Figure 3 This is a diagram showing the internal structure of the driver's cab according to the first embodiment.

[0017] Figure 4 This is a schematic block diagram showing the structure of the computer according to the first embodiment.

[0018] Figure 5 This is a diagram illustrating an outline of the calibration method for the distance sensor of the operating machinery according to the first embodiment.

[0019] Figure 6 This is a flowchart illustrating a calibration method for the distance sensor of the operating machinery according to the first embodiment.

[0020] Figure 7 This is a diagram illustrating an outline of the calibration method for the distance sensor of the operating machinery according to the second embodiment.

[0021] Figure 8 This is a flowchart illustrating a calibration method for the distance sensor of the operating machinery according to the second embodiment.

[0022] Figure 9 This is a diagram illustrating an outline of the calibration method for the distance sensor of the operating machinery according to the third embodiment.

[0023] Figure 10 This is a flowchart illustrating a calibration method for the distance sensor of the operating machinery according to the third embodiment. Detailed Implementation

[0024] <Coordinate System>

[0025] Figure 1 This is a diagram showing an example of the posture of the working machine 100.

[0026] In the following description, a three-dimensional field coordinate system (Xg, Yg, Zg), a three-dimensional vehicle body coordinate system (Xm, Ym, Zm), and a three-dimensional sensor coordinate system (Xs, Ys, Zs) are defined, and positional relationships are described based on them.

[0027] The on-site coordinate system is a coordinate system based on the location of a GNSS (Global Navigation Satellite System) reference station set up at the construction site, and consists of an Xg axis extending north-south, a Yg axis extending east-west, and a Zg axis extending vertically. An example of GNSS is GPS (Global Positioning System). It should be noted that in other implementations, a global coordinate system using latitude and longitude may be used instead of the on-site coordinate system.

[0028] The vehicle body coordinate system is based on a representative point O on the rotating body 130 of the work machinery 100, and is composed of the Xm axis extending forward and backward, the Ym axis extending left and right, and the Zm axis extending up and down when viewed from the operator's seat position in the cab 170 (described later). Using the representative point O of the rotating body 130 as a reference, the forward direction is referred to as +Xm, the rear direction as -Xm, the left direction as +Ym, the right direction as -Ym, the upward direction as +Zm, and the downward direction as -Zm.

[0029] The field coordinate system and the vehicle coordinate system can be converted to each other by determining the position and tilt of the working machine 100 in the field coordinate system.

[0030] The sensor coordinate system is based on the position of the distance sensor provided by the working machine 100, and is composed of the Xs axis extending along the measurement direction of the distance sensor, the Ys axis extending horizontally, and the Zs axis extending vertically.

[0031] Since the distance sensor is fixed to the vehicle body, if the location of the distance sensor in the vehicle body is known, the sensor's vehicle body coordinate system and the sensor's coordinate system can be converted to each other.

[0032] <First Implementation Method>

[0033] Structure of Operation Machinery 100

[0034] Figure 2 This is a schematic diagram showing the structure of the work machine 100 according to the first embodiment.

[0035] The work machinery 100 operates at the construction site, excavating objects such as sand and soil. In the first embodiment, the work machinery 100 is a hydraulic excavator.

[0036] The operating machinery 100 includes a traveling body 110, a rotating body 130, a working device 150, and a driver's cab 170.

[0037] The traveling body 110 supports the working machine 100 for movement. The traveling body 110 is, for example, a pair of tracks on the left and right sides. The slewing body 130 is supported on the traveling body 110 in a manner that allows it to rotate about a center of rotation. The working device 150 is hydraulically driven. The working device 150 is supported at the front of the slewing body 130 in a manner that allows it to be driven vertically. The operator's cab 170 is a space for the operator to sit in and operate the working machine 100. The operator's cab 170 is located at the front of the slewing body 130.

[0038] Structure of Rotary Body 130

[0039] like Figure 2 As shown, the rotating body 130 includes a position orientation detector 131, a tilt detector 132, and a distance sensor 133.

[0040] The position and orientation detector 131 calculates the position of the rotating body 130 in the local coordinate system and the azimuth of the rotating body 130. The position and orientation detector 131 has two antennas that receive positioning signals from artificial satellites constituting GNSS. The two antennas are respectively positioned at different locations on the rotating body 130. For example, the two antennas are positioned at the counterweight of the rotating body 130. Based on the positioning signal received by at least one of the two antennas, the position and orientation detector 131 detects the position of a representative point O of the rotating body 130 in the local coordinate system. The position and orientation detector 131 uses the positioning signals received by the two antennas respectively to detect the azimuth of the rotating body 130 in the local coordinate system.

[0041] The tilt detector 132 measures the acceleration and angular velocity of the rotating body 130, and detects the tilt angle of the rotating body 130 (e.g., the roll angle representing rotation relative to the Xm axis, and the pitch angle representing rotation relative to the Ym axis) based on the measurement results. The tilt detector 132 is, for example, located below the cab 170. An example of the tilt detector 132 is an IMU (Inertial Measurement Unit).

[0042] Distance sensor 133 is installed on the rotating body 130 to detect the distance to objects within its measurement range. Distance sensor 133 is installed on both sides of the rotating body 130 and detects the surrounding distances, including the work object, within a measurement range centered on an axis (Xs axis) extending in the width direction of the rotating body 130. Therefore, when the work machinery 100 is excavating sand using the working device 150, distance sensor 133 can detect the distance to a transport vehicle (not shown) storing the sand object parked to the side of the work machinery 100. Additionally, when the work machinery 100 is loading sand into the transport vehicle, distance sensor 133 can detect the distance to the work object.

[0043] The distance sensor 133 is positioned where its measurement range does not interfere with the working device 150. In other words, the distance sensor 133 measures distances within a range not covered by the working device 150. Examples of distance sensors 133 include LiDAR devices, radar devices, and stereo cameras. Since the distance sensor 133 is positioned where its measurement range does not interfere with the working device 150, it can also be located elsewhere on the rotating body 130, other than on its side. For example, the distance sensor 133 can be located at a point capable of detecting distances to the upper part of the rotating body 130 and to the side of the vehicle body. Alternatively, the distance sensor 133 can be located only on one side of the rotating body 130.

[0044] The distance sensor 133 is configured to be detachable relative to the rotating body 130. The distance sensor 133 is an example of an on-board distance sensor.

[0045] Structure of Working Device 150

[0046] like Figure 2 As shown, the working device 150 includes a boom 151, a stick 152, and a bucket 155.

[0047] The base end of the boom 151 is mounted to the slewing body 130 via boom pin P1. The stick 152 connects the boom 151 and the bucket 155. The base end of the stick 152 is mounted to the front end of the boom 151 via stick pin P2.

[0048] The bucket 155 has a shovel tip for digging sand and soil, and a receiving section for collecting the dug sand and soil. The base end of the bucket 155 is mounted to the front end of the stick 152 via a bucket pin P5.

[0049] The working device 150 includes multiple hydraulic cylinders that serve as actuators for generating power. Specifically, the working device 150 includes a boom cylinder 156, a stick cylinder 157, and a bucket cylinder 158.

[0050] The boom cylinder 156 is a hydraulic cylinder used to operate the boom 151. The base end of the boom cylinder 156 is mounted on the slewing body 130. The front end of the boom cylinder 156 is mounted on the boom 151. A boom cylinder stroke sensor 1561 for detecting the stroke amount of the boom cylinder 156 is provided in the boom cylinder 156.

[0051] The boom cylinder 157 is a hydraulic cylinder used to drive the boom 152. The base end of the boom cylinder 157 is mounted to the boom 151. The front end of the boom cylinder 157 is mounted to the boom 152. A boom cylinder stroke sensor 1571 is provided in the boom cylinder 157 to detect the stroke amount of the boom cylinder 157. The bucket cylinder 158 is a hydraulic cylinder used to drive the bucket 155. The base end of the bucket cylinder 158 is mounted to the boom 152. The front end of the bucket cylinder 158 is mounted to the bucket 155. A bucket cylinder stroke sensor 1581 is provided in the bucket cylinder 158 to detect the stroke amount of the bucket cylinder 158.

[0052] Structure of the driver's cab 170

[0053] Figure 3 This is a diagram showing the internal structure of the driver's cab according to the first embodiment.

[0054] like Figure 3 As shown, the driver's seat 171, operating device 172 and control device 173 are provided in the driver's cab 170.

[0055] The operating device 172 is an interface for driving the traveling body 110, the rotating body 130, and the working device 150 through manual operation by the operator. The operating device 172 includes a left operating lever 1721, a right operating lever 1722, a left foot pedal 1723, a right foot pedal 1724, a left travel lever 1725, and a right travel lever 1726.

[0056] The left control lever 1721 is located on the left side of the driver's seat 171. The right control lever 1722 is located on the right side of the driver's seat 171.

[0057] The left operating lever 1721 is an operating mechanism for rotating the slewing body 130 and pulling and pushing the stick 152. Specifically, when the operator tilts the left operating lever 1721 forward, the stick cylinder 157 is driven, and the stick 152 pushes. Conversely, when the operator tilts the left operating lever 1721 backward, the stick cylinder 157 is driven, and the stick 152 pulls. Furthermore, when the operator tilts the left operating lever 1721 to the right, the slewing body 130 rotates to the right. And when the operator tilts the left operating lever 1721 to the left, the slewing body 130 rotates to the left.

[0058] The right control lever 1722 is an operating mechanism for performing digging and unloading operations of the bucket 155, as well as lifting and lowering operations of the boom 151. Specifically, when the operator tilts the right control lever 1722 forward, the boom cylinder 156 is activated, performing the lowering operation of the boom 151. Conversely, when the operator tilts the right control lever 1722 backward, the boom cylinder 156 is activated, performing the lifting operation of the boom 151. Furthermore, when the operator tilts the right control lever 1722 to the right, the bucket cylinder 158 is activated, performing the unloading operation of the bucket 155. Finally, when the operator tilts the right control lever 1722 to the left, the bucket cylinder 158 is activated, performing the digging operation of the bucket 155. It should be noted that the relationship between the operating directions of the left operating lever 1721 and the right operating lever 1722 and the operating direction of the working device 150 and the rotation direction of the rotating body 130 may not be the relationship described above.

[0059] The left foot pedal 1723 is located on the left side of the floor surface in front of the driver's seat 171. The right foot pedal 1724 is located on the right side of the floor surface in front of the driver's seat 171. The left travel lever 1725 is pivotally supported on the left foot pedal 1723, and is configured such that the tilting of the left travel lever 1725 is linked to the depressing of the left foot pedal 1723. The right travel lever 1726 is pivotally supported on the right foot pedal 1724, and is configured such that the tilting of the right travel lever 1726 is linked to the depressing of the right foot pedal 1724.

[0060] The left foot pedal 1723 and the left travel lever 1725 correspond to the rotation drive of the left track of the traveling body 110. Specifically, when the drive wheel of the traveling body 110 is in the rear, when the operator reverses the left foot pedal 1723 or the left travel lever 1725 forward, the left track rotates in the forward direction. Conversely, when the operator reverses the left foot pedal 1723 or the left travel lever 1725 backward, the left track rotates in the backward direction.

[0061] The right foot pedal 1724 and the right travel lever 1726 correspond to the rotation drive of the right track of the traveling body 110. Specifically, when the drive wheel of the traveling body 110 is in the rear, when the operator reverses the right foot pedal 1724 or the right travel lever 1726 forward, the right track rotates in the forward direction. Conversely, when the operator reverses the right foot pedal 1724 or the right travel lever 1726 backward, the right track rotates in the reverse direction.

[0062] The control device 173 controls the traveling body 110, the rotating body 130, and the working device 150 based on operator input. The control device 173 is an input / output device and includes a display 1731 that shows information related to various functions of the working machine 100. The control device 173 is an example of a calibration device. In the first embodiment, the input method for the control device 173 is a hard key. It should be noted that in other embodiments, a touch panel, mouse, or keyboard may also be used as the input method. Furthermore, while the control device 173 and the display 1731 are integrated in the first embodiment, in other embodiments, the display 1731 may be separate from the control device 173.

[0063] Structure of Control Device 173

[0064] Figure 4 This is a schematic block diagram showing the structure of the computer according to the first embodiment.

[0065] The control device 173 is a computer equipped with a processor 210, a main memory 230, a storage device 250, and an interface 270.

[0066] The display 1731 is connected to the processor 210 via interface 270.

[0067] Storage 250 is a non-temporary tangible storage medium. Examples of storage 250 include magnetic disks, optical disks, optical discs, and semiconductor memories. Storage 250 can be an internal medium directly connected to the bus of control device 173, or an external medium connected to control device 173 via interface 270 or a communication line. Storage 250 stores calibration programs for calibrating distance sensor 133.

[0068] The calibration program can be a program used to implement the functions of the control device 173. For example, the calibration program can be a program that functions by combining with other programs already stored in the memory 250 or with other programs installed in other devices. It should be noted that in other embodiments, the control device 173 may also have a custom LSI (Large Scale Integrated Circuit) such as a PLD (Programmable Logic Device) in addition to or replacing the above-described structure. Examples of PLDs include PAL (Programmable Array Logic), GAL (Generic Array Logic), CPLD (Complex Programmable Logic Device), and FPGA (Field Programmable Gate Array). In this case, some or all of the functions implemented by the processor 210 may also be implemented by this integrated circuit.

[0069] The processor 210 functions as a display control unit 211, an acquisition unit 212, a position calculation unit 213, an attitude determination unit 214, a correction unit 215, a coordinate transformation unit 216, and a parameter storage unit 217 by executing a correction program.

[0070] The display control unit 211 generates screen data for display on the monitor 1731 and outputs the screen data to the monitor 1731.

[0071] The acquisition unit 212 acquires measurement data from various sensors. Specifically, the acquisition unit 212 acquires measurement data from the position orientation detector 131, tilt detector 132, distance sensor 133, boom cylinder stroke sensor 1561, stick cylinder stroke sensor 1571, and bucket cylinder stroke sensor 1581.

[0072] The position calculation unit 213 calculates the position of the marker M in the sensor coordinate system, which is used in the calibration of the distance sensor 133, based on the measurement data (hereinafter referred to as distance data) acquired by the acquisition unit 212 from the distance sensor 133. The marker M can be a reflective material with a specified reflectivity. Therefore, the position calculation unit 213 can determine the position of the marker M by exploring the portion of the measurement data from the distance sensor 133 that relates to the specified reflectivity.

[0073] The attitude determination unit 214 determines the position of the bucket 155 tip in the vehicle coordinate system based on the measurement data obtained by the acquisition unit 212 from the boom cylinder stroke sensor 1561, stick cylinder stroke sensor 1571, and bucket cylinder stroke sensor 1581. Hereinafter, refer to... Figure 1 The method for determining the position of the bucket 155 tip by the attitude determination unit 214 will be described. First, the attitude determination unit 214 calculates the tilt angle α of the boom 151 based on the measurement data of the boom cylinder stroke sensor 1561. Based on the calculated tilt angle α, the known position of the boom pin P1 in the vehicle coordinate system, and the known length L1 of the boom 151, the attitude determination unit 214 determines the position of the stick pin P2 in the vehicle coordinate system. The attitude determination unit 214 calculates the tilt angle β of the stick 152 based on the measurement data of the stick cylinder stroke sensor 1571. Based on the calculated tilt angle β, the position of the stick pin P2 in the vehicle coordinate system, and the known length L2 of the stick 152, the attitude determination unit 214 determines the position of the bucket pin P5 in the vehicle coordinate system. The attitude determination unit 214 calculates the tilt angle γ of the bucket 155 based on the measurement data of the bucket cylinder stroke sensor 1581. The attitude determination unit 214 determines the position of the tip of the bucket 155 in the vehicle coordinate system based on the calculated tilt angle γ, the position of the bucket pin P5 in the vehicle coordinate system, and the known length L3 of the bucket 155.

[0074] The calibration unit 215 calculates parameters for converting the position in the sensor coordinate system to the position in the vehicle body coordinate system based on the position of the marker M and the position of the bucket tip 155. The calibration unit 215 stores the calculated parameters in the parameter storage unit 217. Examples of parameters include the position and tilt (external parameters) of the distance sensor 133 in the work machine 100.

[0075] The coordinate transformation unit 216 converts the position in the vehicle coordinate system to the position in the field coordinate system based on the measurement data of the position orientation detector 131 and the tilt detector 132 acquired by the acquisition unit 212. In addition, the coordinate transformation unit 216 converts the position in the sensor coordinate system to the position in the vehicle coordinate system based on the parameters stored in the parameter storage unit 217.

[0076] Calibration Methods for Distance Sensors

[0077] Figure 5 This is a diagram showing an outline of the calibration method for the distance sensor 133 of the working machine 100 according to the first embodiment.

[0078] In the first embodiment, multiple markers M are set within the measurement range R of the distance sensor 133 installed on the work machinery 100, and the positions of the markers M are measured. Then, the operator operates the work machinery 100 to align the tip of the bucket 155 with each marker M. Thus, the control device 173 of the work machinery 100 can calibrate the parameters of the distance sensor 133 in such a way that the positions of the markers M measured by the distance sensor 133 coincide with the positions of the markers M calculated based on the position of the bucket tip of the bucket 155. It should be noted that in other embodiments, the control device 173 may use only one marker M to calibrate the parameters of the distance sensor 133. However, it is preferable to use multiple markers M for parameter calibration. By using the positions of multiple markers M, parameters can be calibrated with high accuracy even when the vehicle body tilts.

[0079] Figure 6 This is a flowchart illustrating the calibration method of the distance sensor 133 of the working machine 100 according to the first embodiment.

[0080] When the operator operates the control device 173 and activates the calibration function of the distance sensor 133, the control device 173 begins... Figure 6 The correction process shown.

[0081] First, the display control unit 211 outputs a setting instruction screen to the display 1731, prompting the user to set multiple markers M within the measurement range R of the distance sensor 133 (step S1). The setting instruction screen may include, for example, a prompt such as, "Please set four markers within the measurement range of the distance sensor." Additionally, the setting instruction screen may also include three-dimensional data showing the shape of the measurement range R generated based on the measurement data from the distance sensor 133. Thus, the operator can visually confirm whether the markers M are set within the measurement range R by checking the setting instruction screen.

[0082] After the operator completes the setting of marker M, the operator operates the control device 173 to advance the process. Next, the acquisition unit 212 acquires measurement data from various sensors (step S2). Based on the measurement data acquired in step S2, the position calculation unit 213 determines the position of marker M in the sensor coordinate system (step S3).

[0083] Next, the display control unit 211 outputs an operation instruction screen to the display 1731 (step S4) to remind the operating machinery 100 to align the tip of the bucket 155 with one of the multiple marks M. The operation instruction screen may include, for example, a prompt such as "Please align the tip with the mark." In addition, the operation instruction screen may also include three-dimensional data showing the shape of the measurement range R generated based on the measurement data obtained in step S2.

[0084] The operator operates the operating device 172 to rotate the rotary body 130, drive the working device 150, and bring the tip of the bucket 155 into contact with one of the multiple markers M. While bringing the tip into contact with one of the multiple markers M, the operator operates the control device 173 to input the completion of the movement of the bucket 155 (step S5). For example, the operator can input the completion of the movement of the bucket 155 by touching the portion of the multiple markers M that are in contact with the tip of the bucket 155, which is included in the operation instruction screen and reflects the three-dimensional data, and can output the marker M that is in contact with the bucket 155 to the control device 173.

[0085] Next, the acquisition unit 212 acquires measurement data from various sensors (step S6). Based on the measurement data acquired in step S6 from the boom cylinder stroke sensor 1561, stick cylinder stroke sensor 1571, and bucket cylinder stroke sensor 1581, the attitude determination unit 214 determines the position of the bucket 155 tip in the vehicle coordinate system (step S7). At this time, the position of the bucket 155 tip is approximately consistent with the position of the marker M. In other words, the attitude determination unit 214 is an example of a relationship acquisition unit that obtains the positional relationship between the marker M and the bucket 155 tip.

[0086] The coordinate transformation unit 216, based on the measurement data of the position orientation detector 131 and tilt detector 132 obtained in step S2 and the measurement data of the position orientation detector 131 and tilt detector 132 obtained in step S6, converts the position of the bucket tip 155 calculated in step S7 into the position of the field coordinate system at the time point of step S2 (step S8). In other words, the coordinate transformation unit 216 calculates the changes in position, rotation angle, and tilt by acquiring the difference between the measurement data of the position orientation detector 131 and tilt detector 132 obtained in step S2 and the measurement data of the position orientation detector 131 and tilt detector 132 obtained in step S7. Then, the coordinate transformation unit 216 deforms the position calculated in step S7 based on the calculated changes in position, rotation angle, and tilt, thereby obtaining the position of the field coordinate system at the time point of step S2.

[0087] The correction unit 215 determines whether all of the multiple markers M have come into contact with the tip of the bucket 155 (step S9). For example, the correction unit 215 determines whether the input for the completion of movement in step S5 has been performed the number of times corresponding to the number of markers M specified in step S1. If there are markers M that have not come into contact with the tip of the bucket 155 (step S9: No), the control device 173 returns the processing to step S4 and outputs the operation instruction screen to the display 1731.

[0088] On the other hand, if all of the multiple markers M have come into contact with the tip of the bucket 155 (step S9: Yes), the correction unit 215 calculates the parameters of the distance sensor 133 based on the position of the marker in the sensor coordinate system calculated in step S3 and the position of the tip of the bucket 155 corresponding to each marker M obtained in step S8 (step S10). That is, the position of the tip of the bucket 155 obtained in step S8 represents the position of the marker M in the vehicle coordinate system at the time point of step S2. Therefore, the correction unit 215 makes the positions of the multiple markers M calculated in step S3 consistent with the positions of the multiple buckets 155 obtained in step S8 by calculating the determinant of all overlapping positions and performing a coordinate transformation, thereby determining the position and tilt of the distance sensor 133 in the working machine 100.

[0089] The correction unit 215 stores the parameters calculated in step S10 in the parameter storage unit 217 (step S11).

[0090] Functions and Effects

[0091] Thus, the control device 173 of the first embodiment calibrates the parameters of the distance sensor as follows.

[0092] The acquisition unit 212 acquires distance data, measured by the distance sensor 133, of the range in which the marker M, located at any position outside the working machine 100, exists. The position calculation unit 213 calculates the position of the marker M based on the distance data. The attitude determination unit 214 acquires the position of the bucket tip when it contacts the marker M, and uses this position as the positional relationship between the marker M and the bucket tip of the bucket 155, whose position is known in both the vehicle coordinate system and the field coordinate system. The correction unit 215 corrects the parameters determining the position and tilt of the distance sensor 133 in the vehicle coordinate system based on the position of the bucket tip when it contacts the marker M and the position of the marker M measured by the distance sensor 133.

[0093] Therefore, the control device 173 of the first embodiment can calibrate the distance sensor 133 that measures distances not within the range of the working device 150.

[0094] <Second Implementation Method>

[0095] The control device 173 of the first embodiment requires the machine tool 100 to rotate and the working device 150 to drive in order to calibrate the distance sensor 133. In contrast, the control device 173 of the second embodiment calibrates the distance sensor 133 without operating the machine tool 100.

[0096] Figure 7This is a diagram showing an outline of the calibration method for the distance sensor 133 of the working machine 100 according to the second embodiment.

[0097] In the second embodiment, after measuring the positions of multiple markers M and the tip of the bucket 155 using the distance sensor 133 removed from the work machine 100, the distance sensor 133 is installed on the work machine 100 and the positions of each marker M are measured again. Thus, the control device 173 of the work machine 100 can configure the parameters of the distance sensor 133 in a manner consistent with the relationship between the positions of the markers M and the tip of the bucket 155 measured by the removed distance sensor 133 and the positions of the markers M measured by the installed distance sensor 133 and the positions of the tip of the bucket 155 measured by the cylinder stroke sensor.

[0098] Calibration Methods for Distance Sensors

[0099] Figure 8 This is a flowchart illustrating the calibration method of the distance sensor 133 of the working machine 100 according to the second embodiment.

[0100] When the operator operates the control device 173 to activate the calibration function of the distance sensor 133, the control device 173 begins... Figure 8 The correction process shown.

[0101] First, the display control unit 211 outputs a setting instruction screen to the display 1731, prompting the user to set multiple markers M within the measurement range R of the distance sensor 133 (step S31). The setting instruction screen may include, for example, a prompt such as, "Please set four markers within the measurement range of the distance sensor." Additionally, the setting instruction screen may include three-dimensional data showing the shape of the measurement range R generated based on the measurement data from the distance sensor 133. Thus, the operator can visually confirm the setting instruction screen to determine whether the markers M are set within the measurement range R.

[0102] After the operator completes the setting of marker M, the operator operates the control device 173 to advance the process.

[0103] Next, the acquisition unit 212 acquires measurement data from various sensors (step S32). Based on the measurement data acquired in step S32 from the boom cylinder stroke sensor 1561, stick cylinder stroke sensor 1571, and bucket cylinder stroke sensor 1581, the attitude determination unit 214 determines the position of the tip of the bucket 155 in the vehicle coordinate system (step S33).

[0104] Next, the display control unit 211 outputs a measurement instruction screen to the display 1731, reminding users to remove the distance sensor 133 from the operating machine 100 and to measure the range including multiple markers M and the tip of the bucket 155 using the distance sensor 133 (step S34). The measurement instruction screen includes, for example, guidance text such as "Please reinstall the distance sensor after removing it and measuring the distance between the markers and the tip of the bucket."

[0105] The operator removes the distance sensor 133 from the work machinery 100 and measures the range including the tip of the bucket 155 and multiple markers M. The distance sensor 133 may also have a measurement button, for example, allowing the operator to perform manual measurements based on the distance sensor 133 by pressing the button.

[0106] After the operator installs the distance sensor 133 onto the work machine 100, the acquisition unit 212 acquires the distance data measured during the period when the distance sensor 133 is removed (step S35). The distance data measured when the distance sensor 133 is removed is the distance data of the area where the bucket 155 tip and the mark M exist. In other words, the acquisition unit 212 is an example of a relationship acquisition unit that acquires the positional relationship between the mark M and the bucket 155 tip. Based on the measurement data acquired in step S35, the position calculation unit 213 determines the position of the bucket 155 tip and the mark M in the sensor coordinate system when the distance sensor is removed (step S36).

[0107] Next, the acquisition unit 212 acquires the distance data measured after installation from the distance sensor 133 (step S37). Based on the measurement data acquired in step S36, the position calculation unit 213 determines the position of the marker M in the sensor coordinate system after the distance sensor is installed (step S38).

[0108] Next, the calibration unit 215 determines the position of each mark M in the vehicle body coordinate system based on the position of the bucket 155 tip obtained in step S33 and the positions of the bucket 155 tip and mark M in the sensor coordinate system when the distance sensor was removed, calculated in step S36 (step S39). The calibration unit 215 can determine the position of the mark M in the vehicle body coordinate system by aligning the position of the bucket 155 tip and mark M in the vehicle body coordinate system with the position obtained in step S36.

[0109] Next, the calibration unit 215 calculates parameters representing the installation position and tilt of the distance sensor 133 in the work machinery 100 based on the position of the marker M in the sensor coordinate system after the distance sensor is installed, as determined in step S38, and the position of the marker M in the vehicle body coordinate system, as determined in step S39 (step S40). The calibration unit 215 stores the parameters calculated in step S38 in the parameter storage unit 217 (step S41).

[0110] Functions and Effects

[0111] Thus, the control device 173 of the second embodiment calibrates the parameters of the distance sensor as follows.

[0112] The acquisition unit 212 acquires first distance data, measured by the distance sensor 133 installed on the working machine 100, of the range of a marker M located at any position outside the working machine 100. Additionally, the acquisition unit 212 acquires second distance data, measured by the distance sensor 133 removed from the working machine 100, of the range reflecting the tip of the bucket 155 and the marker M, to serve as the positional relationship between the marker M and the tip of the bucket 155, whose position is known in both the vehicle coordinate system and the field coordinate system. The correction unit 215, based on the first and second distance data, corrects the parameters used to measure the position in the vehicle coordinate system based on the distance data from the distance sensor 133.

[0113] Therefore, the control device 173 of the second embodiment can calibrate the distance sensor 133 that measures distances that do not correspond to the range of the working device 150.

[0114] It should be noted that, according to the second embodiment, the distance data measured by the distance sensor 133 removed from the working machine 100 is used as the second distance data, but other embodiments are not limited to this. For example, according to other embodiments, the distance data measured by an external distance sensor prepared separately from the distance sensor 133 may also be used as the second distance data.

[0115] <Third Implementation Method>

[0116] The control device 173 of the first embodiment requires the machine tool 100 to rotate and the working device 150 to drive in order to calibrate the distance sensor 133. In contrast, the control device 173 of the third embodiment calibrates the distance sensor 133 without operating the machine tool 100. The control device 173 of the third embodiment uses measurement data from an external distance sensor 300 to calibrate the distance sensor 133. The external distance sensor 300 has a positioning function to locate its position in the local coordinate system. The control device 173 is connected to the external distance sensor 300 in a manner that enables wireless or wired communication. The control device 173 may also be configured to acquire data from the external distance sensor 300 via a movable medium or the like.

[0117] Figure 9 This is a diagram showing an outline of the calibration method for the distance sensor 133 of the work machine 100 according to the third embodiment.

[0118] In the third embodiment, multiple markers M and an external distance sensor 300 are provided within the measurement range R of the distance sensor 133, and the external distance sensor 300 is used to measure the positions of the multiple markers M. Therefore, the control device 173 of the work machinery 100 can formulate the parameters of the distance sensor 133 based on the position of the external distance sensor in the vehicle body coordinate system when the position of the marker M measured by the distance sensor 133 is aligned with the position of the marker M measured by the external distance sensor 300, and the known position of the external distance sensor in the field coordinate system.

[0119] Calibration Methods for Distance Sensors

[0120] Figure 10 This is a flowchart illustrating the calibration method of the distance sensor 133 of the working machine 100 according to the third embodiment.

[0121] When the operator operates the control device 173 to activate the calibration function of the distance sensor 133, the control device 173 begins... Figure 10 The correction process shown.

[0122] First, the display control unit 211 outputs a setting instruction screen to the display 1731, prompting the user to set multiple markers M within the measurement range R of the distance sensor 133 and an external measuring device (step S51). The setting instruction screen may include, for example, guidance text such as, "Please set four markers within the measurement range of the distance sensor, and set the external distance sensor within this measurement range so that the four markers are reflected." Additionally, the setting instruction screen may include three-dimensional data showing the shape of the measurement range R generated based on the measurement data from the distance sensor 133. Thus, by visually confirming the setting instruction screen, the operator can determine whether the markers M and the external distance sensor 300 are set within the measurement range R.

[0123] After the operator completes the setting of the marker M and the external distance sensor 300, the operator operates the control device 173 to advance the process. The acquisition unit 212 acquires measurement data from various sensors (step S52). The position calculation unit 213 determines the position of the marker M and the external distance sensor 300 in the sensor coordinate system based on the distance data acquired in step S52 (step S53). The coordinate transformation unit 216 converts the position of the marker M and the external distance sensor 300 determined in step S53 into the position in the field coordinate system based on the parameters stored in the parameter storage unit 217 and the measurement data of the position orientation detector 131 and the tilt detector 132 acquired in step S52 (step S54).

[0124] Additionally, the acquisition unit 212 acquires position data and measurement data representing the position of the external distance sensor 300 in the field coordinate system from the external distance sensor 300 (step S55).

[0125] The calibration unit 215 determines the position of each marker M in the field coordinate system based on the position data of the external distance sensor 300 and the measurement data obtained in step S55 (step S56). Next, the calibration unit 215 determines the parameters for the position and tilt of the distance sensor 133 in the working machine 100 in such a way that the difference between the position of the marker M and the external distance sensor 300 in the field coordinate system determined in step S54 and the position of the external distance sensor 300 in the field coordinate system obtained in step S55 and the position of the marker M in the field coordinate system determined in step S56 is minimized (step S57).

[0126] The correction unit 215 stores the parameters calculated in step S57 in the parameter storage unit 217 (step S58).

[0127] Functions and Effects

[0128] Thus, the control device 173 of the third embodiment calibrates the parameters of the distance sensor as follows.

[0129] The acquisition unit 212 acquires first distance data, measured by the distance sensor 133 installed on the work machinery 100, of a marker M located at an arbitrary position outside the work machinery 100, and the range where the external distance sensor 300 exists. Additionally, the acquisition unit 212 acquires second distance data, measured by the external distance sensor 300, of the range corresponding to the marker M, to serve as the positional relationship between the marker M and the external distance sensor 300, whose position is known in both the vehicle coordinate system and the field coordinate system. The correction unit 215, based on the first and second distance data, corrects the parameters used to measure the position in the vehicle coordinate system based on the distance data from the distance sensor 133.

[0130] Therefore, the control device 173 of the third embodiment can calibrate the distance sensor 133 that measures distances that do not correspond to the range of the working device 150.

[0131] <Other Implementation Methods>

[0132] The above description of one embodiment, with reference to the accompanying drawings, is detailed. However, the specific structure is not limited to the above-described manner, and various design changes are possible. That is, in other embodiments, the order of the above-described processes can be appropriately changed. Furthermore, some processes can be executed in parallel.

[0133] For example, in other implementations, a GNSS-RTK (Real Time Kinematic) rover is used to determine the position of multiple markers M in the field coordinate system, and the distance sensor 133 is calibrated based on the position in the field coordinate system.

[0134] Specifically, in other embodiments, the control device 173 can also calibrate the distance sensor 133 according to the following steps: The control device 173 accepts input of the positions of three or more markers M in their respective field coordinate systems, measured using a GNSS-RTK rover. Based on the measurement data obtained from the position orientation detector 131 and the tilt detector 132, the control device 173 converts the positions of the markers M measured by the distance sensor 133 into field coordinate systems. The control device 173 calibrates the parameters of the distance sensor 133 so that the converted positions of the multiple markers M are consistent with the positions of the multiple markers M determined by the GNSS-RTK rover. Alternatively, in other embodiments, the control device 173 can also calibrate the distance sensor 133 according to the following steps: The control device 173 accepts input of the position of a marker M in its field coordinate system, measured using a GNSS-RTK rover. The operator operates the work machinery 100 to measure the positions of the markers M at three or more different locations within the measurement range R of the distance sensor 133 using the distance sensor 133. Based on the measurement data obtained from the position orientation detector 131 and the tilt detector 132, the control device 173 converts the positions of the markers M measured from different locations into the field coordinate system. The control device 173 then corrects the parameters of the distance sensor 133 in such a way that the converted positions of the multiple markers M are consistent with the positions of the markers M determined by the GNSS-RTK rover.

[0135] The control device 173 described above can be a device consisting of a single computer, or it can be a device in which the structure of the control device 173 is separately arranged in multiple computers, and the multiple computers work together to function as the control device 173. In this case, it is also possible that some of the computers constituting the control device 173 are installed inside the machine 100, while other computers are located outside the machine 100.

[0136] According to the above-described embodiment, the attitude of the working device 150 is determined based on the measurement data of the cylinder stroke sensor, but it is not limited to this in other embodiments. For example, in other embodiments, the attitude of the working device 150 may be determined based on IMUs respectively installed on the boom 151, stick 152, and bucket 155, encoders that measure the rotation of each pin, etc., instead of the cylinder stroke sensor.

[0137] Explanation of reference numerals in the attached figures:

[0138] 100…Working machinery; 133…Distance sensor; 150…Working device; 212…Acquisition unit; 213…Position calculation unit; 214…Attitude determination unit; 215…Correction unit.

Claims

1. A calibration device for calibrating an onboard distance sensor installed on a working machine, wherein, The correction device includes: The distance acquisition unit acquires distance data, i.e., first distance data, which is measured by the vehicle-mounted distance sensor and includes the range of a first reference object located at any position outside the operating machinery. The position calculation unit calculates the position of the first reference object in a specified coordinate system based on the first distance data; The relationship acquisition unit acquires the positional relationship between the first reference object and a second reference object whose position is known in the coordinate system. as well as The calibration unit, based on the first distance data and the positional relationship between the first reference object and the second reference object, corrects the parameters used to measure the position in the coordinate system according to the distance data of the vehicle-mounted distance sensor.

2. The calibration device according to claim 1, wherein, The second reference object is the working device of the operating machinery. The relationship acquisition unit acquires the position of the working device when a portion of the working device comes into contact with the first reference object.

3. The calibration device according to claim 1, wherein, The second reference object is the working device of the operating machinery. The relationship acquisition unit acquires the second distance data, which is the distance data of the range between the working device and the first reference object, measured by an external distance sensor located outside the working machinery.

4. The calibration device according to claim 3, wherein, The vehicle-mounted distance sensor is installed on the operating machinery in a detachable manner. The external distance sensor is the vehicle-mounted distance sensor removed from the operating machinery.

5. The calibration device according to claim 1, wherein, The second reference object is an external distance sensor with positioning function installed outside the operating machinery. The relationship acquisition unit acquires distance data of the range in which the first reference object exists, as measured by the external distance sensor.

6. The calibration device according to claim 5, wherein, The first distance data is the distance data within the range where the external distance sensor and the first reference object exist.

7. The calibration device according to claim 1, wherein, The vehicle-mounted distance sensor is positioned at a location where the second reference object does not interfere with the measurement range of the vehicle-mounted distance sensor.

8. A calibration method, which is a calibration method for an on-board distance sensor installed on a working machine, wherein, The correction method includes the following steps: The first distance data is obtained by measuring the range of a first reference object located at any position outside the operating machinery using the vehicle-mounted distance sensor. Obtain the positional relationship between the first reference object and the second reference object whose position is known; as well as Based on the first distance data and the positional relationship between the first reference object and the second reference object, the parameters used to measure the position in a specified coordinate system according to the distance data of the vehicle-mounted distance sensor are corrected.

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