Measurement system of work machine, and measurement method of work machine

Abstract

To measure an error in an attaching posture of a posture sensor that detects a posture of a work machine.SOLUTION: A measurement system of a work machine comprises: a posture sensor attached to a work device of the work machine and detecting a rotational posture around each of three reference axes of a work device coordinate system defined for the work device; and a calculation unit for calculating a detected rotation axis based on detection data detected by the posture sensor when the work device is changed from a first posture to a second posture and calculating an attaching posture error of the posture sensor based on the detected rotation axis and an index axis.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a measurement system for a work machine and a measurement method for a work machine. [Background technology]

[0002] In the technical field of construction machines, there is known a technique for excavating an excavation target based on a target construction surface. Known techniques for excavating an excavation target based on a target construction surface include a machine guidance technique that presents a guidance image showing the relative position of the target construction surface and the work machine to the operator of the work machine, and a machine control technique that assists and controls the operator's operation so that the work machine operates in accordance with the target construction surface. Also known in the technical field of construction machines is a work machine equipped with an inertial measurement unit (IMU), as disclosed in Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-067498 Summary of the Invention [Problem to be solved by the invention]

[0004] When excavating an excavation target based on a target construction surface, it is necessary to detect the attitude of the work machine. When detecting the attitude of the work machine using an attitude sensor attached to the work machine, if there is an error in the installation attitude of the attitude sensor, it may be difficult to excavate the excavation target based on the target construction surface.

[0005] The present disclosure aims to measure an installation attitude error of an attitude sensor that detects the attitude of a work machine. [Means for solving the problem]

[0006] According to the present disclosure, there is provided a measurement system for a work machine, comprising: an attitude sensor attached to a work implement of the work machine, which detects the attitude in the rotational direction centered on each of three reference axes of a work implement coordinate system defined for the work implement; and a calculation unit which calculates a detected rotation axis based on detection data detected by the attitude sensor when the work implement is changed from a first attitude to a second attitude, and calculates an installation attitude error of the attitude sensor based on the detection data, the detected rotation axis, and an index axis. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to measure an installation attitude error of an attitude sensor that detects the attitude of a work machine. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing a work machine according to an embodiment. [Figure 2] FIG. 2 is a schematic diagram showing a work machine according to an embodiment. [Figure 3] FIG. 3 is a block diagram showing a measurement system for a work machine according to the embodiment. [Figure 4] FIG. 4 is a diagram for explaining the operation of the work machine when measuring the mounting attitude error of the attitude sensor according to the embodiment. [Figure 5] FIG. 5 is a diagram for explaining the operation of the work machine when measuring the mounting attitude error of the attitude sensor according to the embodiment. [Figure 6] FIG. 6 is a diagram for explaining a sensor work system in the case where there is no mounting attitude error of the attitude sensor according to the embodiment. [Figure 7] FIG. 7 is a diagram for explaining a sensor work system when there is an error in the mounting posture of the posture sensor according to the embodiment. [Figure 8] FIG. 8 is a diagram for explaining the detection rotation axis when there is no mounting attitude error of the attitude sensor according to the embodiment. [Figure 9]FIG. 9 is a diagram for explaining the detection rotation axis when there is an error in the mounting posture of the posture sensor according to the embodiment. [Figure 10] FIG. 10 is a flowchart showing a method for measuring an error difference in the mounting posture of the posture sensor according to the embodiment. [Figure 11] FIG. 11 is a flowchart showing a control method for a work machine according to an embodiment. [Figure 12] FIG. 12 is a schematic diagram showing a control method for a work machine according to an embodiment. [Figure 13] FIG. 13 is a block diagram illustrating a computer system according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings, but the present disclosure is not limited to the embodiments. The components of the embodiments described below can be combined as appropriate. In addition, some components may not be used.

[0010] [Work machinery] Fig. 1 is a perspective view showing a work machine 1 according to an embodiment. Fig. 2 is a schematic diagram showing a work machine 1 according to an embodiment.

[0011] The work machine 1 operates at a work site. In this embodiment, the work machine 1 is a shovel. The work machine 1 may be a hydraulic shovel or an electric shovel. The work machine 1 includes a traveling body 2, a revolving body 3, a work implement 4, a work implement cylinder 5, an attitude sensor 6, and an on-board controller 7.

[0012] As shown in FIG. 2, a three-dimensional work machine coordinate system (Xm, Ym, Zm) is defined for the work machine 4. A three-dimensional sensor coordinate system (Xs, Ys, Zs) is defined for the posture sensor 6. The work machine coordinate system is composed of the Xm axis extending in the left-right direction of the work machine 4, the Ym axis extending in the front-rear direction of the work machine 4, and the Zm axis extending in the up-down direction of the work machine 4. The Xm axis, Ym axis, and Zm axis are mutually orthogonal. The sensor coordinate system is composed of the Xs axis extending in the left-right direction of the posture sensor 6, the Ys axis extending in the front-rear direction of the posture sensor 6, and the Zs axis extending in the up-down direction of the posture sensor 6. The Xs axis, Ys axis, and Zs axis are mutually orthogonal.

[0013] The running body 2 runs while supporting the rotating body 3. The running body 2 has a pair of tracks 2A. The running body 2 runs by the rotation of the tracks 2A. The work machine 1 can move around the work site by using the running body 2.

[0014] The rotating unit 3 is the body of the work machine 1. The rotating unit 3 is supported by the running unit 2. The rotating unit 3 is positioned higher than the running unit 2. The rotating unit 3 rotates while being supported by the running unit 2. A driver's cab is provided on the rotating unit 3.

[0015] The work implement 4 is supported by the rotating body 3. The work implement 4 performs work. In this embodiment, the work performed by the work implement 4 includes an excavation work of excavating an excavation target and a loading work of loading excavated material onto a loading target. The work implement 4 includes a boom 4A, an arm 4B, and a bucket 4C. The base end of the boom 4A is rotatably connected to the front of the rotating body 3. The base end of the arm 4B is rotatably connected to the tip of the boom 4A. The base end of the bucket 4C is rotatably connected to the tip of the arm 4B.

[0016] The work implement 4 rotates around a work implement rotation axis that is parallel to the Xm axis. As shown in FIG. 2, the work implement rotation axis includes a boom rotation axis AX1, an arm rotation axis AX2, and a bucket rotation axis AX3. The base end of the boom 4A is rotatable around the boom rotation axis AX1. The base end of the arm 4B is rotatable around the arm rotation axis AX2. The base end of the bucket 4C is rotatable around the bucket rotation axis AX3.

[0017] The work implement cylinder 5 operates the work implement 4. The work implement cylinder 5 may be a hydraulic cylinder or an electric cylinder. The work implement cylinder 5 includes a boom cylinder 5A, an arm cylinder 5B, and a bucket cylinder 5C. The boom cylinder 5A raises and lowers the boom 4A. The arm cylinder 5B performs digging and dumping operations on the arm 4B. The bucket cylinder 5C performs digging and dumping operations on the bucket 4C. The base end of the boom cylinder 5A is connected to the revolving unit 3. The tip end of the boom cylinder 5A is connected to the boom 4A. The base end of the arm cylinder 5B is connected to the boom 4A. The tip end of the arm cylinder 5B is connected to the arm 4B. The base end of the bucket cylinder 5C is connected to the arm 4B. The tip end of the bucket cylinder 5C is connected to the bucket 4C.

[0018] The boom 4A rotates within the movable range of the boom 4A. When the boom 4A is raised, it is positioned at the upper end of the movable range of the boom 4A, and when it is lowered, it is positioned at the lower end of the movable range of the boom 4A. The arm 4B rotates within the movable range of the arm 4B. When the arm 4B is dumped, it is positioned at the upper end of the movable range of the arm 4B, and when it is excavated, it is positioned at the lower end of the movable range of the arm 4B. The bucket 4C rotates within the movable range of the bucket 4C. When the bucket 4C is dumped, it is positioned at the upper end of the movable range of the bucket 4C, and when it is excavated, it is positioned at the lower end of the movable range of the bucket 4C.

[0019] The attitude sensor 6 detects the attitude of the work implement 4. The attitude sensor 6 is attached to the work implement 4. The attitude sensor 6 detects the attitude of the work implement 4 in the rotation direction around each of the three reference axes of a work implement coordinate system defined for the work implement 4. The three reference axes of the work implement coordinate system are the Xm axis, the Ym axis, and the Zm axis. The attitude sensor 6 detects the attitude of the work implement 4 in the rotation direction around the Xm axis, the attitude of the work implement 4 in the rotation direction around the Ym axis, and the attitude of the work implement 4 in the rotation direction around the Zm axis. The attitude of the work implement 4 in the rotation direction indicates the rotation angle of the work implement 4. The attitude sensor 6 detects a roll angle that indicates the rotation angle of the work implement 4 around the Xm axis, a pitch angle that indicates the rotation angle of the work implement 4 around the Ym axis, and a yaw angle that indicates the rotation angle of the work implement 4 around the Zm axis.

[0020] In this embodiment, the posture sensors 6 include a posture sensor 6A attached to the boom 4A and a posture sensor 6B attached to the arm 4B. The posture sensor 6A detects the posture of the boom 4A in the rotation direction about each of the Xm-axis, Ym-axis, and Zm-axis of the boom 4A. The posture sensor 6B detects the posture of the arm 4B in the rotation direction about each of the Xm-axis, Ym-axis, and Zm-axis of the arm 4B.

[0021] In this embodiment, the attitude sensor 6 includes an inertial measurement unit (IMU). The attitude sensor 6 has an inertial sensor unit that detects the acceleration and angular velocity of the work implement 4, and an arithmetic circuit unit that includes a microcomputer. The attitude sensor 6 detects the attitude of the work implement 4 in the rotational direction about each of the Xm-axis, Ym-axis, and Zm-axis based on the detection data of the acceleration and angular velocity of the work implement 4.

[0022] The inertial sensor unit of the posture sensor 6 calculates the posture of the work implement 4 in the sensor coordinate system (Xs, Ys, Zs). The inertial sensor unit of the posture sensor 6 calculates the posture of the work implement 4 in the rotation direction about the Xs axis, the posture of the work implement 4 in the rotation direction about the Ys axis, and the posture of the work implement 4 in the rotation direction about the Zs axis. The arithmetic circuit unit of the posture sensor 6 calculates the posture of the work implement 4 in the work implement coordinate system (Xm, Ym, Zm) based on the posture of the work implement 4 in the sensor coordinate system (Xs, Ys, Zs). The posture of the work implement 4 in the sensor coordinate system (Xs, Ys, Zs) is converted into the posture of the work implement 4 in the work implement coordinate system (Xm, Ym, Zm).

[0023] [Measurement system] 3 is a block diagram showing a measurement system 10 of a work machine 1 according to an embodiment. In this embodiment, the measurement system 10 measures at least an attachment attitude error of an attitude sensor 6 relative to the work implement 4. The attitude sensor 6 is attached to the work implement 4. When the work implement coordinate system and the sensor coordinate system are parallel, there is no attachment attitude error of the attitude sensor 6. When the work implement coordinate system and the sensor coordinate system are not parallel, there is an attachment attitude error of the attitude sensor 6. In other words, when at least one of the following states exists: the Xm-axis and the Xs-axis are non-parallel, the Ym-axis and the Ys-axis are non-parallel, and the Zm-axis and the Zs-axis are non-parallel, there is an attachment attitude error of the attitude sensor 6.

[0024] The measurement system 10 has an on-board controller 7, an attitude sensor 6, a work implement cylinder 5, an operation lever 8, and an information terminal 9. The on-board controller 7, the attitude sensor 6, the work implement cylinder 5, and the operation lever 8 are each provided on the work machine 1. The information terminal 9 is disposed outside the work machine 1. The information terminal 9 has a controller 19 and an output device 20.

[0025] The work lever 8 is arranged in the cab of the work machine 1. The work lever 8 is operated by an operator in the cab. By operating the work lever 8, the work implement cylinder 5 is driven and the work implement 4 operates. The operator can enter the cab while holding the information terminal 9. The information terminal 9 may be fixed to a predetermined location in the cab. The information terminal 9 may be considered to be part of the work machine 1.

[0026] The on-vehicle controller 7 includes a computer system. The controller 19 also includes a computer system. The on-vehicle controller 7 and the controller 19 can communicate wirelessly. The on-vehicle controller 7 has a detection data acquisition unit 11, a control unit 13, and a communication unit 14. The controller 19 has a communication unit 15, a guidance unit 16, a calculation unit 17, and an output unit 18. The attitude sensor 6 has a correction unit 12. As described above, the attitude sensor 6 has an inertial sensor unit that detects the acceleration and angular velocity of the work machine 4, and an arithmetic circuit unit that includes a microcomputer. The arithmetic circuit unit of the attitude sensor 6 has the correction unit 12.

[0027] The detection data acquisition unit 11 acquires detection data from the attitude sensor 6. The detection data from the attitude sensor 6 indicates the attitude of the work implement 4. The detection data from the attitude sensor 6 acquired by the detection data acquisition unit 11 indicates the attitude of the work implement 4 in the sensor coordinate system (Xs, Ys, Zs) detected by the inertial sensor unit of the attitude sensor 6. The communication unit 14 transmits the detection data from the attitude sensor 6 acquired by the detection data acquisition unit 11 to the information terminal 9. The communication unit 15 of the information terminal 9 acquires the detection data from the attitude sensor 6 transmitted from the on-board controller 7.

[0028] The guidance unit 16 generates guidance data when measuring the mounting attitude error of the attitude sensor 6. The output unit 18 outputs the guidance data generated by the guidance unit 16 to the output device 20. The output device 20 includes a display device or an audio output device provided in the information terminal 9. When the output device 20 is a display device, the output unit 18 displays the guidance data on the display device.

[0029] The calculation unit 17 calculates the mounting attitude error of the attitude sensor 6 with respect to the work implement 4. The calculation unit 17 calculates the detection rotation axis AXs based on the detection data detected by the attitude sensor 6 when the work implement 4 is changed from the first attitude to the second attitude. The calculation unit 17 calculates the mounting attitude error of the attitude sensor 6 based on the detection rotation axis AXs and the Xs axis. Here, the Xs axis is the X axis extending in the left-right direction of the attitude sensor 6. The Xs axis is an index axis that serves as an index used when calculating the mounting attitude error.

[0030] The calculation unit 17 calculates the detected rotation axis AXs based on the attitude of the work implement 4 in the sensor coordinate system (Xs, Ys, Zs) detected by the inertial sensor unit of the attitude sensor 6. The attitude of the work implement 4 in the sensor coordinate system (Xs, Ys, Zs) includes the attitude of the work implement 4 in the rotation direction about the Xs axis, the attitude of the work implement 4 in the rotation direction about the Ys axis, and the attitude of the work implement 4 in the rotation direction about the Zs axis. The calculation unit 17 calculates the mounting attitude error of the attitude sensor 6 based on the calculated detected rotation axis AXs and the attitude of the work implement 4 in the rotation direction about the Xs axis detected by the inertial sensor unit of the attitude sensor 6. The calculation unit 17 calculates the detected rotation axis AXs using a quaternion.

[0031] The output unit 18 outputs calculation data indicating the calculation result of the calculation unit 17 to the communication unit 15. The calculation data of the calculation unit 17 indicates the mounting attitude error of the attitude sensor 6. The communication unit 15 transmits the calculation data of the calculation unit 17 to the in-vehicle controller 7. The communication unit 14 of the in-vehicle controller 7 acquires the calculation data of the calculation unit 17 transmitted from the information terminal 9. The communication unit 14 transfers the calculation data of the calculation unit 17 transmitted from the information terminal 9 to the correction unit 12 of the attitude sensor 6.

[0032] The correction unit 12 corrects the detection data of the attitude sensor 6 based on the mounting attitude error of the attitude sensor 6 calculated by the calculation unit 17. When work is performed by the work implement 4, the correction unit 12 corrects the detection data of the attitude sensor 6 based on the mounting attitude error of the attitude sensor 6 calculated by the calculation unit 17. The correction unit 12 corrects the detection data of the attitude sensor 6 so as to reduce the detection error of the attitude sensor 6 caused by the mounting attitude error of the attitude sensor 6. The correction unit 12 corrects the attitude of the work implement 4 in the sensor coordinate system (Xs, Ys, Zs) based on the mounting attitude error of the attitude sensor 6 and converts it into the attitude of the work implement 4 in the work implement coordinate system (Xm, Ym, Zm). The correction unit 12 corrects at least one of the detection data of the pitch angle indicating the rotation angle of the work implement 4 about the Ym axis and the detection data of the yaw angle indicating the rotation angle of the work implement 4 about the Zm axis. The correction unit 12 calculates the amount of correction to reduce the detection error of the pitch angle. The correction unit 12 calculates a correction amount for reducing the detection error of the yaw angle.

[0033] The control unit 13 controls the work implement cylinder 5 to control the operation of the work implement 4. Control of the work implement cylinder 5 includes drive control of the work implement cylinder 5. The control unit 13 controls the operation of the work implement 4 based on an operation command generated by operating the work lever 8. In the embodiment, the control unit 13 assists and controls the operation of the operator so that the work implement 4 operates in accordance with the target construction surface 30. During excavation work on an excavation target, the control unit 13 controls the operation of the work implement 4 so that the bucket 4C moves along the target construction surface based on the detection data of the attitude sensor 6 corrected by the correction unit 12.

[0034] [Measurement of the installation position error of the position sensor] 4 and 5 are diagrams illustrating the operation of the work implement 4 when measuring the installation attitude error of the attitude sensor 6 according to the embodiment. Fig. 4 shows the operation of the work implement 4 when measuring the installation attitude error of the attitude sensor 6A attached to the boom 4A. Fig. 5 shows the operation of the work implement 4 when measuring the installation attitude error of the attitude sensor 6B attached to the arm 4B.

[0035] As shown in Fig. 4, when measuring the mounting attitude error of the attitude sensor 6A, the operator operates the working lever 8 so that the boom 4A moves but the arm 4B and bucket 4C do not move. In other words, when measuring the mounting attitude error of the attitude sensor 6A, the operator operates the working lever 8 so that the boom cylinder 5A drives but the arm cylinder 5B and bucket cylinder 5C do not drive. The boom 4A rotates around the boom rotation axis AX1.

[0036] In this embodiment, the operator operates the working lever 8 so as to change the work implement 4 from the initial position (first position) to a boom-raising position (second position). As an example, the initial position of the work implement 4 refers to a position in which the boom 4A is positioned at the lower end of the movable range of the boom 4A, the arm 4B is positioned at the lower end of the movable range of the arm 4B, and the bucket 4C is positioned at the lower end of the movable range of the bucket 4C. The boom-raising position refers to a position in which the boom 4A is positioned at the upper end of the movable range of the boom 4A, the arm 4B is positioned at the lower end of the movable range of the arm 4B, and the bucket 4C is positioned at the lower end of the movable range of the bucket 4C. The operator can change the work implement 4 from the initial position to the boom-raising position by raising the boom 4A while stopping the movements of the arm 4B and the bucket 4C.

[0037] As shown in Fig. 5, when measuring the mounting attitude error of the attitude sensor 6B, the operator operates the working lever 8 so that the arm 4B moves but the boom 4A and bucket 4C do not move. In other words, when measuring the mounting attitude error of the attitude sensor 6B, the operator operates the working lever 8 so that the arm cylinder 5B is driven but the boom cylinder 5A and bucket cylinder 5C are not driven. The arm 4B rotates around the arm rotation axis AX2.

[0038] In this embodiment, the operator operates the work lever 8 so as to change the work implement 4 from a boom-raised position (first position) to an arm-raised position (second position). As an example, the arm-raised position of the work implement 4 refers to a position in which the boom 4A is positioned at the upper end of the movable range of the boom 4A, the arm 4B is positioned at the upper end of the movable range of the arm 4B, and the bucket 4C is positioned at the lower end of the movable range of the bucket 4C. The operator can change the work implement 4 from the boom-raised position to the arm-raised position by performing a dumping operation on the arm 4B while stopping the movement of the boom 4A and the bucket 4C.

[0039] When measuring the mounting attitude error of the attitude sensor 6 (6A, 6B), the operator gets into the cab while holding the information terminal 9. When measuring the mounting attitude error of the attitude sensor 6, the operator starts up application software stored in the controller 19 of the information terminal 9. The application software is application software used to measure the mounting attitude error of the attitude sensor 6. When the application software is started up, the functions of the communication unit 15, guidance unit 16, calculation unit 17, and output unit 18 are each fulfilled. Note that the operator who operates the work machine 1 and the operator who operates the information terminal 9 may be the same operator or different operators.

[0040] When measuring the mounting attitude error of the attitude sensor 6A, the guidance unit 16 generates guidance data for changing the work implement 4 from the initial attitude to the boom-raising attitude. The output unit 18 outputs the guidance data generated by the guidance unit 16 to the output device 20. By checking the guidance data output to the output device 20, the operator can operate the work lever 8 so as to change the work implement 4 from the initial attitude to the boom-raising attitude.

[0041] When measuring the mounting attitude error of the attitude sensor 6B, the guidance unit 16 generates guidance data for changing the work implement 4 from the boom-raising attitude to the arm-raising attitude. The output unit 18 outputs the guidance data generated by the guidance unit 16 to the output device 20. By checking the guidance data output to the output device 20, the operator can operate the work lever 8 so as to change the work implement 4 from the boom-raising attitude to the arm-raising attitude.

[0042] The following describes the procedure for measuring the mounting attitude error of the attitude sensor 6B. The procedure for measuring the mounting attitude error of the attitude sensor 6A is similar to the procedure for measuring the mounting attitude error of the attitude sensor 6B, so the description will be simplified or omitted.

[0043] As described above, when measuring the mounting attitude error of the attitude sensor 6B, the operator operates the work lever 8 so that the arm 4B moves but the boom 4A and bucket 4C do not move. The arm 4B rotates about the arm rotation axis AX2. The arm rotation axis AX2 is parallel to the Xm axis. By operating the arm 4B to rotate about the arm rotation axis AX2, which is parallel to the Xm axis among the Xm axis, Ym axis, and Zm axis, the arm 4B changes from the boom-raising attitude (first attitude) to the arm-raising attitude (second attitude).

[0044] Fig. 6 is a diagram for explaining a sensor work system when there is no mounting attitude error of the attitude sensor 6B according to the embodiment. Fig. 7 is a diagram for explaining a sensor work system when there is a mounting attitude error of the attitude sensor 6B according to the embodiment.

[0045] A state in which there is no mounting attitude error in the attitude sensor 6B is a state in which the work machine coordinate system and the sensor coordinate system are parallel. A state in which there is no mounting attitude error in the attitude sensor 6B is a state in which the Xm axis and the Xs axis are parallel, the Ym axis and the Ys axis are parallel, and the Zm axis and the Zs axis are parallel. A state in which there is no mounting attitude error is a state in which the Xs axis in the boom-up attitude (first attitude) and the Xs axis in the arm-up attitude (second attitude) are parallel. A state in which there is a mounting attitude error in the attitude sensor 6B is a state in which the work machine coordinate system and the sensor coordinate system are not parallel. A state in which there is a mounting attitude error in the attitude sensor 6B includes at least one of a state in which the Xm axis and the Xs axis are not parallel, a state in which the Ym axis and the Ys axis are not parallel, and a state in which the Zm axis and the Zs axis are not parallel.

[0046] As shown in FIG. 6, if there is no mounting attitude error in the attitude sensor 6B, the Xm axis and Xs axis remain parallel even when the work implement 4 changes from the boom-up attitude to the arm-up attitude.

[0047] As shown in FIG. 7, if there is an error in the mounting posture of the posture sensor 6B, when the work implement 4 changes from the boom-up posture to the arm-up posture, the Xm axis and the Xs axis become non-parallel.

[0048] The calculation unit 17 can calculate a change in the orientation of the sensor coordinate system due to a change in the attitude of the work implement 4 using a quaternion based on the detection data of the attitude sensor 6B when the work implement 4 is changed from a boom-raising attitude to an arm-raising attitude.The calculation unit 17 can calculate a detected rotation axis AXs using a quaternion based on the detection data of the attitude sensor 6B when the work implement 4 is changed from a boom-raising attitude to an arm-raising attitude.The detected rotation axis AXs corresponds to a virtual arm rotation axis (work implement rotation axis) calculated based on the detection data of the attitude sensor 6B when the work implement 4 is changed from a boom-raising attitude (first attitude) to an arm-raising attitude (second attitude).The calculation unit 17 calculates at least the orientation (vector) of the detected rotation axis AXs.

[0049] Fig. 8 is a diagram for explaining the detection axis of rotation AXs when there is no mounting attitude error of the attitude sensor 6B according to the embodiment, and Fig. 9 is a diagram for explaining the detection axis of rotation AXs when there is a mounting attitude error of the attitude sensor 6B according to the embodiment.

[0050] 8, if there is no mounting attitude error of the attitude sensor 6B, the Xs axis and the detection rotation axis AXs will be parallel. In other words, if there is no mounting attitude error of the attitude sensor 6B, the actual arm rotation axis AX2 and the detection rotation axis AXs will be parallel.

[0051] 9, if there is an error in the mounting posture of posture sensor 6B, the Xs axis and the detection rotation axis AXs will be non-parallel. In other words, if there is an error in the mounting posture of posture sensor 6B, the actual arm rotation axis AX2 and the detection rotation axis AXs will not be parallel.

[0052] The calculation unit 17 calculates the mounting attitude error of the attitude sensor 6B based on the detection rotation axis AXs and the Xs axis detected by the attitude sensor 6B when the work implement 4 is changed from the boom-up attitude (first attitude) to the arm-up attitude (second attitude). The calculation unit 17 calculates the angular difference between the work implement coordinate system and the sensor coordinate system as the mounting attitude error of the attitude sensor 6B. The calculation unit 17 calculates the angular difference between the Xs axis and the detection rotation axis AXs as the mounting attitude error of the attitude sensor 6B. As shown in FIG. 8, if there is no mounting attitude error of the attitude sensor 6B, the angular difference between the Xs axis and the detection rotation axis AXs is zero. As shown in FIG. 9, the larger the mounting attitude error of the attitude sensor 6B, the larger the angular difference between the Xs axis and the detection rotation axis AXs.

[0053] [Measurement method] 10 is a flowchart showing a method for measuring an installation attitude error of the attitude sensor 6B according to the embodiment. The operator gets into the driver's cab while carrying the information terminal 9. The operator operates the information terminal 9 to start up application software used to measure the installation attitude error of the attitude sensor 6.

[0054] When measuring the mounting attitude error of the attitude sensor 6B, the guidance unit 16 generates guidance data for changing the work implement 4 from the boom-raising attitude to the arm-raising attitude. The output unit 18 outputs the guidance data generated by the guidance unit 16 to the output device 20. By checking the guidance data output to the output device 20, the operator can operate the work lever 8 so as to change the work implement 4 from the boom-raising attitude to the arm-raising attitude.

[0055] The detection data acquisition unit 11 acquires detection data from the posture sensor 6B when the work implement 4 is in the boom-up posture (step SA1).

[0056] The detection data acquisition unit 11 acquires the detection data of the posture sensor 6B when the work machine 4 is in the arm-raised posture (step SA2).

[0057] The detection data of the attitude sensor 6B when the work implement 4 is in the boom-up attitude and the detection data of the attitude sensor 6B when the work implement 4 is in the arm-up attitude are transmitted from the on-vehicle controller 7 to the information terminal 9.

[0058] The calculation unit 17 calculates the detected rotation axis AXs based on the detection data of the posture sensor 6B when the work implement 4 is in the boom-up posture and the detection data of the posture sensor 6B when the work implement 4 is in the arm-up posture. The calculation unit 17 calculates at least the orientation of the detected rotation axis AXs (step SA3).

[0059] The calculation unit 17 calculates the mounting attitude error of the attitude sensor 6B based on the detection rotation axis AXs calculated in step SA3 and the Xs axis (X axis of the attitude sensor 6). In the embodiment, the calculation unit 17 calculates the angular difference between the Xs axis (X axis of the attitude sensor 6) and the detection rotation axis AXs calculated in step SA3 as the mounting attitude error of the attitude sensor 6B (step SA4).

[0060] The mounting attitude error of the attitude sensor 6B has been described above. The procedure for measuring the mounting attitude error of the attitude sensor 6A is the same as the procedure for measuring the mounting attitude error of the attitude sensor 6B. When measuring the mounting attitude error of the attitude sensor 6A, the work implement 4 is operated to change from the initial attitude to the boom-raised attitude. The calculation unit 17 can calculate the mounting attitude error of the attitude sensor 6A based on the detected rotation axis AXs and Xs axis detected by the attitude sensor 6A when the work implement 4 is changed from the initial attitude (first attitude) to the boom-raised attitude (second attitude). The detected rotation axis AXs calculated based on the detection data of the attitude sensor 6A corresponds to the virtual boom rotation axis (work implement rotation axis) calculated based on the detection data of the attitude sensor 6A when the work implement 4 is changed from the initial attitude (first attitude) to the boom-raised attitude (second attitude).

[0061] [Control method] 11 is a flowchart showing a control method for the work machine 1 according to the embodiment. An example of excavating an excavation target based on machine control technology will be described below.

[0062] During excavation of an excavation target, the attitude of the work machine 4 is detected by the attitude sensor 6. The detection data acquisition unit 11 acquires the detection data of the attitude sensor 6 (step SB1).

[0063] The correction unit 12 corrects the detection data of the attitude sensor 6 acquired in step SB1 based on the mounting attitude error calculated in step SA4 (step SB2).

[0064] The correction unit 12 corrects the detection data of the attitude sensor 6 so as to reduce errors in the detection data of the attitude sensor 6 caused by installation attitude errors. As described with reference to Fig. 9, when there is an angular difference between the Xs axis (X axis of the attitude sensor 6) and the detection rotation axis AXs, the correction unit 12 corrects the detection data of the attitude sensor 6 so as to reduce errors in the detection data of the attitude sensor 6 caused by the angular difference. The correction unit 12 corrects the orientation of the sensor coordinate system based on the angular difference so that the Xs axis (X axis of the attitude sensor 6) and the detection rotation axis AXs are parallel, and corrects the pitch angle and yaw angle of the work implement 4 detected by the attitude sensor 6 based on the corrected sensor coordinate system.

[0065] The control unit 13 calculates the position of the cutting edge of the bucket 4C based on the detection data of the attitude sensor 6 corrected by the correction unit 12 in step SB2, the dimensional data of the work implement 4 which is known data, and the detection data of a GNSS (Global Navigation Satellite System) receiver (not shown) provided on the rotating body 3 (step SB3).

[0066] The control unit 13 assist-controls the work machine 4 based on the position of the cutting edge of the bucket 4C calculated in step SB3 and the target construction surface 30 (step SB4).

[0067] Fig. 12 is a schematic diagram showing a control method for the work machine 1 according to the embodiment. As shown in Fig. 12, a target construction surface 30 is set for the excavation target. The control unit 13 controls the operation of the work machine 4 so that the cutting edge of the bucket 4C moves along the target construction surface 30, based on the detection data of the attitude sensor 6 corrected by the correction unit 12, known dimensional data of the work machine 4, and detection data of the GNSS receiver provided on the revolving body 3. The control unit 13 assists and controls the operation of the operator so that the cutting edge of the bucket 4C moves along the target construction surface 30.

[0068] [Computer System] FIG. 13 is a block diagram showing a computer system 1000 according to an embodiment. The above-described on-board controller 7 and controller 19 each include a computer system 1000. The computer system 1000 includes a processor 1001 such as a central processing unit (CPU), a main memory 1002 including a nonvolatile memory such as a read-only memory (ROM) and a volatile memory such as a random access memory (RAM), a storage 1003, and an interface 1004 including an input / output circuit. The functions of the above-described on-board controller 7 and controller 19 are stored in the storage 1003 as computer programs. The processor 1001 reads the computer programs from the storage 1003, loads them into the main memory 1002, and executes the above-described processes according to the programs. The computer programs may be distributed to the computer system 1000 via a network.

[0069] According to the above-described embodiment, the computer program or computer system 1000 can execute the following operations: when an attitude sensor 6 is attached to the work implement 4 of the work machine 1, the attitude sensor 6 detects the rotational attitude around each of the three reference axes (Xm-axis, Ym-axis, Zm-axis) of the work implement coordinate system defined for the work implement 4; change the work implement 4 from a first attitude to a second attitude; calculate detection data detected by the attitude sensor 6 when the work implement 4 is changed from the first attitude to the second attitude and a detected rotation axis based on the detection data; and calculate an attachment attitude error of the attitude sensor 6 based on the detected rotation axis and the index axis.

[0070] [effect] As described above, according to the embodiment, the calculation unit 17 can calculate the detected rotation axis AXs using quaternions based on the detection data of the attitude sensor 6 when the work implement 4 is changed from the first attitude to the second attitude. The calculation unit 17 can calculate the angle difference between the detected rotation axis AXs and the Xs axis as the mounting attitude error of the attitude sensor 6. During work using the work implement 4, the correction unit 12 can calculate correction amounts to reduce the detection errors of the pitch angle and yaw angle of the work implement 4 detected by the attitude sensor 6, based on the mounting attitude error.

[0071] [Other embodiments] In the above-described embodiments, at least some of the functions of the in-vehicle controller 7 may be provided in the attitude sensor 6 or the information terminal 9. At least some of the functions of the information terminal 9 may be provided in the attitude sensor 6 or the in-vehicle controller 7. At least some of the functions of the attitude sensor 6 may be provided in the in-vehicle controller 7 or the information terminal 9. For example, the function of the calculation unit 17 may be provided in the in-vehicle controller 7 or the attitude sensor 6. For example, the function of the correction unit 12 may be provided in the in-vehicle controller 7 or the information terminal 9.

[0072] In the above-described embodiment, each of the detection data acquisition unit 11, correction unit 12, control unit 13, communication unit 14, communication unit 15, guidance unit 16, calculation unit 17, and output unit 18 may be configured by separate hardware (processors).

[0073] In the above-described embodiment, the work machine 1 is an excavator having a running body 2 and a rotating body 3. The work machine 1 does not have to have the running body 2 and the rotating body 3. The work machine 1 only needs to have a working implement, and may be, for example, a bulldozer, a wheel loader, or a motor grader. [Explanation of symbols]

[0074] 1... Excavator (work machine), 2... Traveling body, 2A... Track, 3... Swinging body, 4... Work machine, 4A... Boom, 4B... Arm, 4C... Bucket, 5... Work machine cylinder, 5A... Boom cylinder, 5B... Arm cylinder, 5C... Bucket cylinder, 6... Posture sensor, 6A... Posture sensor, 6B... Posture sensor, 7... On-board controller, 8... Work lever, 9... Information terminal, 10... Measurement system, 11... Detection data acquisition unit, 12... Correction unit, 13... Control unit, 14... Communication unit, 15...communication unit, 16...guidance unit, 17...calculation unit, 18...output unit, 19...controller, 20...output device, 30...target construction surface, AX1...boom rotation axis (work equipment rotation axis), AX2...arm rotation axis (work equipment rotation axis), AX3...bucket rotation axis (work equipment rotation axis), AXs...detection rotation axis, 1000...computer system, 1001...processor, 1002...main memory, 1003...storage, 1004...interface.

Claims

1. an attitude sensor attached to a work implement of a work machine, which detects the attitude of the work implement in a rotational direction about each of three reference axes of a work implement coordinate system defined for the work implement; a calculation unit that calculates a detected rotation axis based on detection data detected by the attitude sensor when the work machine is changed from a first attitude to a second attitude, and calculates an installation attitude error of the attitude sensor based on the detected rotation axis and an index axis, Measurement system for work machines.

2. The work machine is changed from the first posture to the second posture by being operated to rotate about a work machine rotation axis that is parallel to a first reference axis among the three reference axes. The measurement system for a work machine according to claim 1 .

3. the calculation unit calculates, as the mounting attitude error, an angular difference between the index axis and the detection rotation axis. The measurement system for a work machine according to claim 2.

4. The work implement includes a boom, The attitude sensor is attached to the boom. The measurement system for a work machine according to claim 1 .

5. The work machine includes an arm, The attitude sensor is attached to the arm. The measurement system for a work machine according to claim 1 .

6. a correction unit that corrects the detection data of the attitude sensor based on the mounting attitude error calculated by the calculation unit; The measurement system for a work machine according to claim 1 .

7. The work machine includes a boom, an arm connected to the boom, and a bucket connected to the arm, the attitude sensor is attached to each of the boom and the arm, A control unit is provided that controls the operation of the work machine so that the bucket moves along a target construction surface based on the detection data corrected by the correction unit. The measurement system for a work machine according to claim 6.

8. the attitude sensor includes an inertial measurement unit; The measurement system for a work machine according to claim 1 .

9. changing the work implement from a first posture to a second posture in a state in which posture sensors are attached to the work implement of the work machine, the posture sensors detecting postures in rotation directions around each of three reference axes of a work implement coordinate system defined for the work implement; calculating a detected rotation axis based on detection data detected by the attitude sensor when the work machine is changed from a first attitude to a second attitude, and calculating an installation attitude error of the attitude sensor based on the detected rotation axis and an index axis. How to measure work machines.

Images