Positioning system for work machinery, work machinery, and method for positioning work machinery

Abstract

To provide a positioning system for a work machine that can appropriately execute initialization processing, in RTK positioning using GNSS, a work machine, and a positioning method for a work machine.SOLUTION: A positioning system 200 for a work machine 1 using RTK positioning using a satellite positioning system is provided with a sensor controller 40 which is a calculation unit that calculates the positions of antennas 61 and 62 of the satellite positioning system located in the work machine 1, based on a position of a work machine 4 of the work machine 1 aligned with a known reference point PR positioned at a work site, and a monitor controller 51 which is an initialization control unit that outputs control commands to cause a receiver of the satellite positioning system performing positioning calculations by RTK positioning, to perform initialization processing of positioning calculation in which the integer bias of each satellite and the positions of antennas 61 and 62 of the satellite positioning system are unknown, using the calculated positions of antennas 61 and 62 of the satellite positioning system.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a positioning system for a work machine, a work machine, and a method for positioning a work machine.

Background Art

[0002] In recent years, in work machines such as hydraulic excavators, the use of ICT (Information and Communication Technology) has been promoted. For example, there are work machines that detect the position of a work machine by mounting GNSS (Global Navigation Satellite Systems) or the like, compare the position information of the work machine with the current terrain data indicating the current terrain of the work site, and calculate and obtain the position or posture of the work machine (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a work machine, when performing real-time kinematic (RTK: Realtime Kinematic) positioning using GNSS (hereinafter referred to as "RTK positioning"), it is necessary to perform an initialization process. However, when the distance between the fixed station and the mobile station is long, or when there are obstacles around the mobile station, etc., the calculation for estimating and determining the integer value bias of each satellite may not converge, and the initialization process may not be completed.

[0005] The present disclosure has been made in view of the above, and an object thereof is to provide a positioning system for a work machine, a work machine, and a method for positioning a work machine that can appropriately execute an initialization process in RTK positioning using GNSS.

Means for Solving the Problems

[0006] In accordance with aspects of the present disclosure, a positioning system for a work machine using real-time kinematic positioning with a satellite positioning system is provided, comprising: a calculation unit that calculates the position of an antenna of a satellite positioning system placed on the work machine based on the position of the work machine of the work machine aligned with a known reference point positioned at a work site; and an initialization control unit that outputs a control command to a receiver of a satellite positioning system that performs positioning calculations by real-time kinematic positioning, causing it to perform an initialization process for positioning calculations using the position of the antenna of the satellite positioning system calculated by the calculation unit, with integer bias values ​​for each satellite and the position of the antenna of the satellite positioning system as unknowns. [Effects of the Invention]

[0007] According to the embodiments of this disclosure, initialization processing can be appropriately performed in RTK positioning using GNSS. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a perspective view showing the work machine according to this embodiment. [Figure 2] Figure 2 shows the operator's cab of the work machine according to this embodiment. [Figure 3] Figure 3 is a diagram illustrating the positioning of the work machine. [Figure 4] Figure 4 is a schematic diagram showing the positioning system of the work machine according to this embodiment. [Figure 5] Figure 5 is a block diagram showing an example of a positioning system for a work machine according to this embodiment. [Figure 6] Figure 6 is a block diagram showing the computer system according to this embodiment. [Figure 7] Figure 7 is a flowchart showing an example of a positioning method for a work machine according to this embodiment. [Modes for carrying out the invention]

[0009] Hereinafter, embodiments of the positioning system for work machines, work machines, and positioning methods for work machines relating to this disclosure will be described with reference to the drawings. However, this invention is not limited by these embodiments. Furthermore, the components in the following embodiments include those that are easily substituted or substantially identical to those that are easily substituted by those skilled in the art.

[0010] Figure 1 is a perspective view showing a work machine 1 according to this embodiment. In this embodiment, the work machine 1 is a hydraulic excavator. In the following description, the work machine 1 will be referred to as the hydraulic excavator 1. The hydraulic excavator 1 comprises a lower traveling body 2, an upper rotating body 3 supported by the lower traveling body 2, a work implement 4 supported by the upper rotating body 3, and a hydraulic cylinder 5 that drives the work implement 4.

[0011] The lower running body 2 is capable of moving while supporting the upper rotating body 3. The lower running body 2 has a pair of tracks. The lower running body 2 moves as the tracks rotate.

[0012] The upper slewing body 3 is supported by the lower traveling body 2 and can rotate around the slewing axis RX relative to the lower traveling body 2. The upper slewing body 3 has a cab 6 in which the operator of the hydraulic excavator 1 sits. The cab 6 is equipped with an operator's seat 9 in which the operator sits.

[0013] The work machine 4 includes a boom 4A connected to the upper slewing body 3, an arm 4B connected to the boom 4A, and a bucket 4C connected to the arm 4B. The hydraulic cylinder 5 includes a boom cylinder 5A that drives the boom 4A, an arm cylinder 5B that drives the arm 4B, and a bucket cylinder 5C that drives the bucket 4C.

[0014] The boom 4A is supported by the upper slewing body 3 so as to be rotatable around the boom rotation axis AX. The arm 4B is supported by the boom 4A so as to be rotatable around the arm rotation axis BX. The bucket 4C is supported by the arm 4B so as to be rotatable around the bucket rotation axis CX.

[0015] The boom rotation axis AX, the arm rotation axis BX, and the bucket rotation axis CX are parallel. The boom rotation axis AX, the arm rotation axis BX, and the bucket rotation axis CX are orthogonal to the axis parallel to the slewing axis RX. In the following description, the direction parallel to the slewing axis RX is referred to as the vertical direction, the direction parallel to the boom rotation axis AX, the arm rotation axis BX, and the bucket rotation axis CX is referred to as the left - right direction, and the direction orthogonal to both the boom rotation axis AX, the arm rotation axis BX, and the bucket rotation axis CX and the slewing axis RX is referred to as the front - rear direction. Based on the driver seated in the driver's cab 9, the direction in which the working machine 4 exists is the front, and the opposite direction of the front is the rear. Based on the driver seated in the driver's cab 9, one of the left - right directions is the right, and the opposite direction of the right is the left. The direction away from the ground contact surface of the lower traveling body 2 is the upper, and the opposite direction of the upper is the lower.

[0016] The driver's cab 6 is arranged in front of the upper slewing body 3. The driver's cab 6 is arranged to the left of the working machine 4. The boom 4A of the working machine 4 is arranged to the right of the driver's cab 6.

[0017] [Driver's cab] FIG. 2 is a view showing the driver's cab 6 of the hydraulic excavator 1 according to the present embodiment. The hydraulic excavator 1 includes an operation unit 10 arranged in the driver's cab 6. The operation unit 10 is operated for the operation of at least a part of the hydraulic excavator 1. The operation unit 10 is operated by the driver seated in the driver's seat 9. The operation of the hydraulic excavator 1 includes at least one of the operation of the lower traveling body 2, the operation of the upper slewing body 3, and the operation of the working machine 4.

[0018] The operation unit 10 includes a left working lever 11 and a right working lever 12 operated for the operation of the upper slewing body 3 and the working machine 4, a left traveling lever 13 and a right traveling lever 14 operated for the operation of the lower traveling body 2, and a left foot pedal 15 and a right foot pedal 16.

[0019] The left working lever 11 is arranged to the left of the driver's seat 9. When the left working lever 11 is operated in the front-rear direction, the arm 4B performs a dumping operation or an excavation operation. When the left working lever 11 is operated in the left-right direction, the upper slewing body 3 performs a left slewing or a right slewing. The right working lever 12 is arranged to the right of the driver's seat 9. When the right working lever 12 is operated in the left-right direction, the bucket 4C performs an excavation operation or a dumping operation. When the right working lever 12 is operated in the front-rear direction, the boom 4A performs a lowering operation or a raising operation.

[0020] The left traveling lever 13 and the right traveling lever 14 are arranged in front of the driver's seat 9. The left traveling lever 13 is arranged to the left of the right traveling lever 14. When the left traveling lever 13 is operated in the front-rear direction, the crawler on the left side of the lower traveling body 2 performs a forward movement or a backward movement. When the right traveling lever 14 is operated in the front-rear direction, the crawler on the right side of the lower traveling body 2 performs a forward movement or a backward movement.

[0021] The left foot pedal 15 and the right foot pedal 1 are arranged in front of the driver's seat 9. The left foot pedal 15 is arranged to the left of the right foot pedal 16. The left foot pedal 15 is interlocked with the left traveling lever 13. The right foot pedal 16 is interlocked with the right traveling lever 14. When the left foot pedal 15 and the right foot pedal 16 are operated, the lower traveling body 2 may perform a forward movement or a backward movement.

[0022] [Positioning System] FIG. 3 is a diagram for explaining the positioning of the hydraulic excavator

[0023] As shown in Figure 3, RTK positioning is a method in which the position of the mobile station MS is determined by measuring the carrier phase transmitted by multiple GNSS satellites SV using GNSS receivers RC, which are receivers of the satellite positioning system installed on the fixed station FS located at a known point PF and the mobile station MS, respectively. Figure 3 illustrates GNSS satellites SV1, SV2, SV3, and SV4.

[0024] The carrier phase is the sum of the variations in distance between each GNSS satellite SV and the GNSS receiver RC. The number of wavenumbers (called "integer bias" or "ambiguity") between each GNSS satellite SV and the GNSS receiver RC is unknown when the GNSS receiver RC is in its initial state (immediately after startup). Therefore, as part of its initialization process, the GNSS receiver RC onboard the mobile station MS searches for the position of the mobile station that minimizes the distance error between each satellite (called a convergence calculation) to determine the highly accurate position of the mobile station and the integer bias of each GNSS satellite SV.

[0025] The GNSS receiver RC uses correction information from the fixed station FS to correct the received position information and determine the mobile station's position. However, if the distance between the fixed station FS and the mobile station MS is long, the correction effect of the correction information deteriorates, and the error in the position measured by the GNSS receiver RC increases. This increase in error makes it difficult for the GNSS receiver RC to search for its position during the initialization process, preventing it from determining the mobile station MS's position with high accuracy, and potentially preventing the initialization process from completing.

[0026] Therefore, the positioning system 200 first calculates the position of the mobile station MS by a method other than RTK positioning. Then, based on the calculated position of the mobile station MS, the positioning system 200 has the GNSS receiver RC mounted on the mobile station MS perform an initialization process, thereby reducing the number of unknown variables and making it easier for the integer bias calculation to converge. In this embodiment, the positioning system 200 calculates the position of the GNSS antenna 61, which is the antenna of the satellite positioning system placed on the hydraulic excavator 1, based on the position of the cutting edge 4Cp of the work machine 4 of the hydraulic excavator 1, which is aligned with a known reference point PR positioned at the work site. The positioning system 200 outputs a control command to the GNSS receiver 60, which performs positioning calculations by RTK positioning, to perform an initialization process for positioning calculations using the calculated position of the GNSS antenna 61, with the integer bias of each GNSS satellite and the position of the GNSS antenna 61 as unknowns.

[0027] The positioning system 200 includes a cylinder stroke sensor 5a for detecting the stroke length of each cylinder of the work machine 4, an IMU (Inertial Measurement Unit) 30, a sensor controller (calculation unit) 40, a monitor controller (initialization control unit) 51 of the monitor 50, a GNSS receiver 60, and GNSS antennas 61 and 62. The GNSS antenna 61 is used to determine the position of the hydraulic excavator 1, and the GNSS antenna 62 is used to determine the yaw angle, which is the azimuth angle of the hydraulic excavator 1's body.

[0028] The cylinder stroke sensor 5a detects information representing the posture of the work machine 4. The cylinder stroke sensor 5a includes a boom cylinder sensor 5Aa, an arm cylinder sensor 5Ba, and a bucket cylinder sensor 5Ca. The boom cylinder sensor 5Aa, arm cylinder sensor 5Ba, and bucket cylinder sensor 5Ca are located on the work machine 4. The boom cylinder sensor 5Aa detects boom cylinder length data, which indicates the stroke length, the amount of movement of the boom cylinder 5A. The arm cylinder sensor 5Ba detects arm cylinder length data, which indicates the stroke length, the amount of movement of the arm cylinder sensor 5Ba. The bucket cylinder sensor 5Ca detects bucket cylinder length data, which indicates the stroke length, the amount of movement of the bucket cylinder 5C. The cylinder stroke sensor 5a outputs the detected cylinder length data to the sensor controller 40.

[0029] The IMU 30 is a state detection device that detects operational information indicating the operation of the hydraulic excavator 1. Antennas 61 and 62 are also examples of state detection devices. In this embodiment, the operational information may include information indicating the posture of the hydraulic excavator 1. Examples of information indicating the posture of the hydraulic excavator 1 include the roll angle, pitch angle, and yaw angle of the hydraulic excavator 1. The IMU 30 is attached to the upper slewing body 3. The IMU 30 may also be installed, for example, below the operator's cab 6.

[0030] The IMU30 detects the angular velocity and acceleration of the hydraulic excavator 1. As the hydraulic excavator 1 operates, various accelerations occur in the excavator 1, such as acceleration generated during travel, angular acceleration generated during rotation, and gravitational acceleration. The IMU30 detects and outputs at least the gravitational acceleration. Here, gravitational acceleration is the acceleration corresponding to the force resisting gravity. For example, in a three-dimensional global coordinate system (X, Y, Z), the IMU30 detects the acceleration in the X-axis, Y-axis, and Z-axis directions, as well as the angular velocity (rotational angular velocity) around the X-axis, Y-axis, and Z-axis.

[0031] A global coordinate system is a coordinate system based on a fixed origin on Earth. Global coordinate systems are defined by GNSS (Global Navigation Satellite System).

[0032] The sensor controller 40 has a processing unit which is a processor such as a CPU (Central Processing Unit), and a storage unit which is a storage device such as RAM (Random Access Memory) and ROM (Read Only Memory). The sensor controller 40 receives the detection values ​​from the IMU 30 and the detection values ​​from the boom cylinder sensor 5Aa, the arm cylinder sensor 5Ba, and the bucket cylinder sensor 5Ca. The sensor controller 40 also receives the position of the hydraulic excavator 1 in global coordinates, which is determined by the GNSS receiver 60, via the monitor controller 51. The sensor controller 40 functions as a calculation unit.

[0033] After the initialization process of the GNSS receiver 60 is completed, the sensor controller 40 generates target cutting edge position data, which indicates the target cutting edge position, based on the cutting edge position data of the hydraulic excavator 1 and the current terrain data indicating the current terrain of the work site. The cutting edge position data is data indicating the current position of the cutting edge 4Cp of the hydraulic excavator 1. The cutting edge position data is generated based on the position of the hydraulic excavator 1 in global coordinates, the detected value of the cylinder stroke sensor 5a, and the detected value of the IMU 30. For example, the target cutting edge position data is generated by creating a virtual target ground by offsetting the current terrain indicated by the current terrain data by a predetermined distance downward, and the cutting edge 4Cp is generated to align with the virtual target ground. Based on the cutting edge position data and the target cutting edge position data, the sensor controller 40 generates and outputs work machine command values ​​that control the operation of the work machine 4.

[0034] The sensor controller 40 calculates the position of the GNSS antenna 61 placed on the work machine 1 based on the position of the cutting edge 4Cp of the work machine 4, which is aligned with a known reference point PR that has been measured at the work site. The sensor controller 40 converts the position of the GNSS antenna 61 of the hydraulic excavator 1, which has been determined in the vehicle coordinate system, to the global coordinate system and outputs it to the monitor controller 51 of the monitor 50.

[0035] The sensor controller 40 may calculate the position of the GNSS antenna 61 based on the position of a known reference point PR and the angle representing the posture of the work implement 4 when the cutting edge 4Cp of the work implement 4 is aligned with the position of the reference point PR. More specifically, the sensor controller 40 determines the position of the GNSS antenna 61 of the hydraulic excavator 1 in the vehicle coordinate system (Xm, Ym, Zm) based on the position of the reference point PR measured in a three-dimensional field coordinate system and the detected value of the cylinder stroke sensor 5a detected when the cutting edge 4Cp of the work implement 4 is aligned with the position of the reference point PR.

[0036] Information representing the posture of the work machine 4 can be obtained from the amount of movement of the boom cylinder 5A indicated by the detection value of the boom cylinder sensor 5Aa, the amount of movement of the arm cylinder 5B indicated by the detection value of the arm cylinder sensor 5Ba, and the amount of movement of the bucket cylinder 5C indicated by the detection value of the bucket cylinder sensor 5Ca. Information representing the posture of the work machine 4 is defined, for example, by the angle θ1 between the boom 4A and the upper slewing body 3, the angle θ2 between the boom 4A and the arm 4B, and the angle θ3 between the arm 4B and the bucket 4C.

[0037] The sensor controller 40 may further calculate the position of the GNSS antenna 61 based on the attitude angles, including the roll angle, pitch angle, and yaw angle, of the hydraulic excavator 1. More specifically, the sensor controller 40 further determines the position of the GNSS antenna 61 of the hydraulic excavator 1 in the vehicle coordinate system based on the detected value of the IMU 30, which is detected when the cutting edge 4Cp of the work implement 4 is aligned with the position of the reference point PR.

[0038] The attitude angles (roll angle and pitch angle) of the hydraulic excavator 1 can be obtained from the angular velocity and acceleration detected by the IMU30. The yaw angle is obtained from the monitor controller 51.

[0039] The monitor 50 displays specified display data. The monitor 50 has a monitor controller 51 and a display unit 52. The display unit 52 may be a separate unit. The monitor controller 51 has a processing unit which is a processor such as a CPU and a storage unit which is a storage device such as RAM and ROM (Read Only Memory). The monitor controller 51 functions as an initialization control unit. The monitor controller 51 outputs a control command to the GNSS receiver 60, which performs positioning calculations by RTK positioning, to execute an initialization process for positioning calculations, using the position of the GNSS antenna 61 calculated by the sensor controller 40, with the integer bias of each GNSS satellite and the position of the GNSS antenna 61 as unknowns. The monitor controller 51 outputs the position of the GNSS antenna 61 of the hydraulic excavator 1, which has been converted to a global coordinate system and obtained from the sensor controller 40, to the GNSS receiver 60.

[0040] The monitor controller 51 determines the yaw angle, which is the azimuth angle of the vehicle body, from the antenna azimuth angle determined by the GNSS receiver 60 and the relative positions of the GNSS antennas 61 and 62 on the vehicle body. It also outputs the determined yaw angle to the sensor controller 40.

[0041] The display unit 52 includes a flat panel display such as a liquid crystal display (LCD) or an organic electroluminescence display (OELD). The display unit 52 can display the progress of the initialization process of the GNSS receiver 60, such as whether the initialization process of the GNSS receiver 60 is in progress or has been completed. The monitor 50 is connected to the sensor controller 40 and the GNSS receiver 60 so as to be able to communicate data.

[0042] The GNSS receiver 60 functions as a global coordinate calculation device. The GNSS receiver 60 has a processing unit, which is a processor such as a CPU, and a storage unit, which is a storage device such as RAM and ROM. The GNSS receiver 60 is a position detection device that uses GNSS to detect the current position of the hydraulic excavator 1. Based on the signal corresponding to the GNSS radio waves received by the GNSS antenna 61, the GNSS receiver 60 determines the position of the GNSS antenna 61 in the global coordinate system shown in Figure 1. An example of GNSS is GPS (Global Positioning System), but it is not limited to this. The GNSS antenna 61 is installed on the hydraulic excavator 1, for example.

[0043] The GNSS antenna 61 is located on the upper rotating body 3. The GNSS antenna 61 is used to detect the current position of the hydraulic excavator 1. The GNSS antenna 61 is connected to the GNSS receiver 60. The signal corresponding to the GNSS radio waves received by the GNSS antenna 61 is input to the GNSS receiver 60.

[0044] In its initialization process, the GNSS receiver 60 estimates and determines the integer bias of each GNSS satellite through convergence calculations to obtain the highly accurate position of the GNSS antenna 61, which is a mobile station. When the initialization process is executed, the GNSS receiver 60 obtains the position of the GNSS antenna 61, expressed in a global coordinate system, from the monitor controller 51 of the monitor 50. Using the position of the GNSS antenna 61 expressed in a global coordinate system, the GNSS receiver 60 estimates and determines the integer bias of each GNSS satellite through convergence calculations.

[0045] After the initialization process is complete, the GNSS receiver 60 outputs the generated position of the GNSS antenna 61 to the monitor controller 51 of the monitor 50.

[0046] The GNSS receiver 60 calculates the azimuth angle from the satellite signals received by the GNSS antennas 61 and 62 through baseline analysis, and uses this azimuth angle as the antenna azimuth angle of GNSS antenna 62 with respect to GNSS antenna 61 as the axis. The GNSS receiver 60 also outputs the calculated antenna azimuth angle to the monitor controller 51.

[0047] [Computer System] Figure 6 is a block diagram showing a computer system 1000 according to this embodiment. The positioning system 200 described above includes the computer system 1000. The computer system 1000 has a processor 1001 such as a CPU (Central Processing Unit), a main memory 1002 including non-volatile memory such as ROM (Read Only Memory) and volatile memory such as RAM (Random Access Memory), a storage 1003, and an interface 1004 including input / output circuits. The functions of the positioning system 200 described above are stored in the storage 1003 as a computer program. The processor 1001 reads the computer program from the storage 1003, loads it into the main memory 1002, and executes the above-mentioned processing according to the computer program. The computer program may be distributed to the computer system 1000 via a network.

[0048] The computer program or computer system 1000 can, in accordance with the above-described embodiment, perform the following actions: align the position of the cutting edge 4Cp of the work machine 4 with a known reference point PR surveyed at the work site; calculate the position of the GNSS antenna 61 placed on the work machine 1 from the position of the reference point to which the cutting edge 4Cp of the work machine 4 has been aligned; and output a control command to the GNSS receiver 60, which performs positioning calculations by real-time kinematic positioning, to perform an initialization process for positioning calculations using the calculated position of the GNSS antenna 61, with the integer bias of each GNSS satellite and the position of the GNSS antenna 61 as unknowns.

[0049] Figure 7 is a flowchart illustrating an example of a positioning method for the hydraulic excavator 1 according to this embodiment. At the work site, the reference point PR is measured in a three-dimensional site coordinate system, and its position is known. When the hydraulic excavator 1 is started, the initialization process of the GNSS receiver 60 is executed. The monitor 50 can display the progress of the initialization process, such as whether the initialization process of the GNSS receiver 60 is being executed or whether the initialization process has been completed. If the initialization process of the GNSS receiver 60 is not completed, for example, the operator can perform the process shown in Figure 7. First, the operator operates the work implement 4 to align the position of the cutting edge 4Cp of the work implement 4 with the reference point PR measured at the work site.

[0050] The positioning system 200 executes steps SP1 to SP5 in the sensor controller 40 and the monitor controller 51 of the monitor 50. In addition, the GNSS receiver 60 executes steps ST1 to ST4.

[0051] The sensor controller 40 calculates the position of the GNSS antenna 61 (step SP1). More specifically, the sensor controller 40 calculates the position of the GNSS antenna 61 of the hydraulic excavator 1 in the vehicle coordinate system based on the position of a known reference point PR, the detected value of the cylinder stroke sensor 5a when the cutting edge 4Cp of the work implement 4 is aligned with the reference point PR, and at least one of the detected values ​​of the IMU 30. The sensor controller 40 outputs the calculated position of the GNSS antenna 61 to the monitor controller 51.

[0052] The monitor controller 51 outputs the position of the GNSS antenna 61, acquired from the sensor controller 40, to the GNSS receiver 60 (step SP2).

[0053] The GNSS receiver 60 obtains the position of the GNSS antenna 61 from the monitor controller 51 (step ST1).

[0054] The monitor controller 51 outputs a control command to the GNSS receiver 60 to perform an initialization process using the position of the GNSS antenna 61 calculated by the sensor controller 40, with the integer bias value of each GNSS satellite and the position of the GNSS antenna 61 as unknowns (step SP3).

[0055] The GNSS receiver 60 interrupts the initialization process that is currently running (step ST2).

[0056] The GNSS receiver 60 performs the initialization process again based on the acquired position of the GNSS antenna 61 (step ST3).

[0057] The monitor controller 51 determines whether the initialization process by the GNSS receiver 60 has been completed (step SP4). If it determines that the initialization process by the GNSS receiver 60 has been completed (Yes in step SP4), the process proceeds to step SP5. If it does not determine that the initialization process by the GNSS receiver 60 has been completed (No in step SP4), the process in step SP4 is executed again.

[0058] The monitor controller 51 outputs a control command to the GNSS receiver 60 to release the fixed position mode of the GNSS antenna 61 (step SP5).

[0059] The GNSS receiver 60 releases the fixed position mode of the GNSS antenna 61 (step ST4). During the initialization process of the GNSS receiver 60, it is set to fixed mode, and processing is performed assuming that the position of the GNSS antenna 61 is fixed. While fixed mode is set, the position of the hydraulic excavator cannot be measured by RTK positioning. By releasing the fixed mode, it becomes possible to measure the high-precision position of the moving hydraulic excavator 1 by RTK positioning.

[0060] In this way, the number of unknown variables is reduced during the initialization process of the GNSS receiver 60, making it easier for the integer bias calculation to converge, and thus the initialization process of the GNSS receiver 60 is completed properly. Even if the hydraulic excavator 1 moves after the initialization process of the GNSS receiver 60 is completed, the highly accurate position of the GNSS antenna 61 mounted on the hydraulic excavator 1 can be determined.

[0061] Note that the flowchart in Figure 7 is an example, and in other embodiments, it is not necessary to perform all steps. For example, although it was described as an example of when the initialization process of the GNSS receiver 60 is not completed, it may be performed even when the initialization process of the GNSS receiver 60 is not completed. In this case, for example, steps ST2 and SP3 may not be performed.

[0062] [effect] As described above, this embodiment causes the GNSS receiver 60, which performs positioning calculations by RTK positioning, to perform an initialization process for positioning calculations based on the position of the GNSS antenna 61 calculated from the position of a known reference point PR. According to this embodiment, the GNSS receiver 60 can estimate and determine the integer bias of each GNSS satellite by convergence calculation using the position of the GNSS antenna 61. According to this embodiment, it is possible to suppress the occurrence of a state in which the initialization process of the GNSS receiver 60 is not completed. This embodiment enables the initialization process of the GNSS receiver 60 to be executed appropriately.

[0063] Although embodiments have been described above, the embodiments are not limited by the above. Furthermore, the components described above include those that can be easily imagined by those skilled in the art, those that are substantially the same, and those that are equivalent. Moreover, the components described above can be combined as appropriate. Furthermore, at least one of various omissions, substitutions, and modifications of the components can be made without departing from the gist of the embodiments. For example, each process described as being performed by the sensor controller 40 may be performed by the monitor controller 51 of the monitor 50 or another controller. For example, each process described as being performed by the monitor controller 51 of the monitor 50 may be performed by the sensor controller 40 or another controller. For example, the functions of the sensor controller 40 and the monitor controller 51 of the monitor 50 may be implemented in a single controller.

[0064] In this embodiment, the task of aligning the cutting edge 4Cp of the work machine 4 with a known reference point PR is a task that has also been performed at the start of work in conventional methods. In this embodiment, since the operator does not perform any new tasks, an increase in workload can be suppressed.

[0065] Furthermore, although the above embodiment uses a hydraulic excavator 1 as an example of a work machine, it is not limited to this, and other work machines such as bulldozers or wheel loaders may also be used.

[0066] Furthermore, although the above embodiment describes aligning the cutting edge 4Cp of the work implement 4 to a known reference point PR, the invention is not limited to this, and other parts of the work implement 4 may be aligned to the known reference point PR.

[0067] In the above embodiment, the yaw angle was described as being calculated by the monitor controller 51, but it may also be calculated by the sensor controller 40. Specifically, the monitor controller 51 outputs the antenna azimuth angle obtained by the GNSS receiver 60 to the sensor controller 40, and the sensor controller 40 calculates the yaw angle from the antenna azimuth angle and the arrangement of the GNSS antennas 61 and 62 on the vehicle body.

[0068] In the above embodiment, the GNSS antenna 61 was described as being used to determine the position of the hydraulic excavator 1, but it is not limited to this. For example, the GNSS antenna 62 may be used as follows: It may also be used to determine the position of the hydraulic excavator 1. In this case, the GNSS antenna 61 may be used to determine the yaw angle, which is the azimuth angle of the hydraulic excavator 1's body. Alternatively, GNSS antennas other than GNSS antenna 61 and GNSS antenna 62 may be provided and used to determine the position of the hydraulic excavator 1.

[0069] In the above embodiment, it was described as having two GNSS antennas, but the invention is not limited to this, and there may be only one GNSS antenna. For example, if the work machine is a bulldozer, the direction of the vehicle may be calculated from the velocity vector detected by one GNSS antenna.

[0070] The implement described above is just one example and can be applied to implements of other work machines, such as bulldozer blades and wheel loader buckets. [Explanation of Symbols]

[0071] 1...Hydraulic excavator (working machine), 2...Lower travel body, 3...Upper slewing body, 4...Working equipment, 4A...Boom, 4B...Arm, 4C...Bucket, 5...Hydraulic cylinder, 5A...Boom cylinder, 5Aa...Boom cylinder sensor, 5B...Arm cylinder, 5Ba...Arm cylinder sensor, 5C...Bucket cylinder, 5Ca...Bucket cylinder sensor, 6...Operator's cab, 9...Operator's seat, 10...Control panel, 11...Left work lever, 12...Right work lever, 13...Left travel lever, 14...Right travel lever, 15...Left foot pedal, 16...Right foot pedal, 30...IMU, 40...Sensor Calculation unit, 50...Monitor, 51...Monitor controller (initialization control unit), 52...Display unit, 60...GNSS receiver (receiver for satellite positioning system), 61...GNSS antenna (antenna for satellite positioning system), 62...GNSS antenna (antenna for satellite positioning system), 200...Positioning system, 1000...Computer system, 1001...Processor, 1002...Main memory, 1003...Storage, 1004...Interface, AX...Boom rotation axis, BX...Arm rotation axis, CX...Bucket rotation axis, RX...Slewing axis.

Claims

1. A positioning system for work machinery using real-time kinematic positioning with a satellite positioning system, A calculation unit calculates the position of the satellite positioning system antenna in the vehicle coordinate system, based on the position of the work machine of the work machine aligned with a known reference point positioned at the work site, using a method other than real-time kinematic positioning. An initialization control unit outputs a control command to the receiver of a satellite positioning system that performs positioning calculations by real-time kinematic positioning, causing it to perform an initialization process for positioning calculations, where the integer bias of each satellite and the position of the antenna of the satellite positioning system are unknowns, using the position of the antenna of the satellite positioning system in the vehicle coordinate system calculated by the calculation unit. A positioning system for work machinery, equipped with the following features.

2. The calculation unit calculates the position of the satellite positioning system antenna in the vehicle coordinate system based on the position of the reference point and the angle representing the attitude of the work machine. A positioning system for a work machine according to claim 1.

3. The calculation unit calculates the position of the satellite positioning system antenna in the vehicle coordinate system based on the attitude angles, including the roll angle, pitch angle, and yaw angle of the work machine. A positioning system for a work machine according to claim 1 or 2.

4. The calculation unit calculates the position of the satellite positioning system antenna in the vehicle coordinate system based on the position of the cutting edge of the work machine, which is aligned with the reference point. A positioning system for a work machine according to any one of claims 1 to 3.

5. A traveling unit that carries the aforementioned work machine, A positioning system for a work machine according to any one of claims 1 to 4, A work machine equipped with the following features.

6. A method for positioning a work machine using real-time kinematic positioning with a satellite positioning system, Aligning a part of the work equipment with a known reference point surveyed at the work site, The position of the satellite positioning system antenna on the work machine in the vehicle coordinate system is calculated from the position of the reference point, which is the position of a part of the work machine, by a method other than real-time kinematic positioning. To output a control command to the receiver of a satellite positioning system that performs positioning calculations by real-time kinematic positioning, causing it to perform an initialization process for positioning calculations, where the integer bias of each satellite and the position of the antenna of the satellite positioning system are unknowns, using the calculated position of the antenna of the satellite positioning system in the vehicle coordinate system; A method for positioning work machinery, including the above.

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