JP2007147588A - Position measuring system for working machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a fluctuation in display when a vehicle body is in a stationary condition, to restrain followability in the display from getting low when the vehicle body is not in a stationary condition, and to enhance working efficiency, when computing and displaying a position and a posture of a working machine in a three-dimensional space, and an absolute position of a monitor point, in a position measuring system for the working machine. <P>SOLUTION: A position and a posture of an upper turning body 3 are found as values of a global coordinate system, based on three-dimensional positions of GPS antennas 31, 32, and the values are subjected to low path filtering processing. The low path filtering processing is carried out therein by a high cut-off frequency for removing a noise component, when a hydraulic shovel 1 turns or travels, and by a low cut-off frequency for restraining the fluctuation in the display when not so. A positional relation of the hydraulic shovel 1 to a geography is displayed superposedly on a monitor, based on computed values. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a position measurement system for a work machine that calculates the absolute position and orientation of a work machine such as a hydraulic excavator in a three-dimensional space and the absolute position of a monitor point set in the work machine in the three-dimensional space.

  2. Description of the Related Art In recent years, work management is performed at a construction site by measuring the position of a monitor point of a traveling work machine using a three-dimensional position measuring device such as GPS.

  As a representative example of the monitor point, there is a position of a working device of a work machine, for example, a bucket tip position of a hydraulic excavator. If the tip position of the bucket can be measured, the progress of the work during construction can be grasped by comparing the measured data with preset terrain data and target shape data, and management during construction can be performed. Moreover, even after construction, construction management can be performed by generating finished shape data (for example, excavation landform data) from the measurement data. As a prior art of such a position measurement system, for example, there is one described in Patent Document 1.

  In the technique described in Patent Document 1, two GPS antennas are installed on the upper swing body of a hydraulic excavator, and the position information of the GPS antennas and the angle of a rotation angle sensor that detects the rotation angles of the boom, arm, and bucket are detected. The absolute position of the bucket in the three-dimensional space is calculated from the information.

  In Patent Document 1, the three-dimensional position of a working machine such as a hydraulic excavator and the direction of the working machine are compared with the three-dimensional target landform, and the plane of the longitudinal section passing through the direction in which the working machine is facing and the three-dimensional target are compared. Proposal of a device that guides the target excavation surface by calculating the three-dimensional intersection line with the terrain and displaying the intersection line on the same screen on the same screen as the vehicle body and work implement on the display device installed in the cab is doing.

JP 2001-98585 A

  In the prior art described in Patent Document 1 described above, in order to calculate the position of the bucket in the three-dimensional space, the two GPS antennas are positioned by the respective GPS receivers based on the signals received by the two GPS antennas. RTK (Real Time Kinematic) measurement of the position of two points on the upper revolving body to be obtained, and a vehicle body coordinate system representing the position and posture of the hydraulic excavator is obtained from the measured position of the two points on the upper revolving body. The absolute position of the bucket in the three-dimensional space is calculated by combining the angle information of the rotation angle sensor attached to the arm and the bucket.

  By the way, in the RTK measurement performed using the GPS that is a three-dimensional position measurement device, the measurement state changes due to the influence of weather, topography, and the like. This measurement state includes FIX (accuracy of about ± 1 to 2 cm), FLOAT (accuracy of about ± 10 cm), DGPS (accuracy of about ± m), and the like. FIX is a normal measurement state, and FLOAT, DGPS, etc. are cases where a normal measurement state cannot be obtained. However, even in the normal measurement state (FIX), measurement results vary within a range of ± 1 to 2 cm due to the arrangement of captured GPS satellites, the influence of the ionosphere, and the like. For this reason, naturally, the value of the vehicle body coordinate system calculated based on the measurement result of GPS also varies. However, in the case of calculating using a plurality of GPSs as in the conventional technique, the calculation is performed. The influence on the result is greater, and even when the vehicle body is stationary without operating the operation lever, the hydraulic excavator displayed on the screen fluctuates and is displayed.

  For example, as described in Patent Document 1, when two GPS antennas are installed on the upper swing body of a hydraulic excavator to obtain a vehicle body coordinate system of the hydraulic excavator, the measured values of the positions of the two GPS antennas are respectively Since it fluctuates in the range of ± 1 to 2 cm, the direction (posture) of the straight line connecting the positions of the two GPS antennas fluctuates with fluctuations in their measured values. In this case, the variation in the direction (posture) of the straight line is greatest when the measured values of the positions of the two GPS antennas vary by ± 2 cm in the opposite direction to the longitudinal direction of the vehicle body. The change in the posture (direction) of the vehicle body coordinate system calculated based on the measured values of the positions of the two GPS antennas corresponds to the change in the direction (posture) of the straight line connecting the positions of the two GPS antennas. When the measured values of the positions of the two GPS antennas fluctuate ± 2 cm in the opposite direction of the vehicle body longitudinal direction, the posture (direction) of the vehicle body coordinate system also fluctuates the most, and the vehicle body and work implement displayed on the display device It will be the biggest fluctuation. In this case, since the bucket of the work implement is particularly located at the tip of the work implement and is far from the two GPS antennas, fluctuations in the measurement values of the bucket position and orientation increase, and the bucket fluctuates greatly accordingly. Is displayed.

  As a result, it takes time to align the bucket and the target terrain, and causes problems such as excavating a place different from the plan, resulting in a decrease in work efficiency.

  As a method for solving this problem, it is conceivable to perform a process for suppressing fluctuations in numerical values by performing a moving average process on the time axis and a low-pass filtering process on the position and orientation calculation values. However, in this case, the work performed in a state where the position or posture of the vehicle body is changed, such as during traveling or turning, the calculation result and display followability of the position and posture are deteriorated. A delay occurs in grasping the positional relationship of the (vehicle body), and work efficiency is reduced.

  The purpose of the present invention is to calculate the position and orientation of the work machine in the three-dimensional space and the absolute position of the monitor point set in the work machine, and when displaying an image of the work machine based on the calculation result, Work that reduces display wobbling when the machine body of the work machine is stationary, reduces the follow-up of the display when the machine body of the work machine is not stationary, and thus improves work efficiency It is to provide a position measurement system for a machine.

  In the present specification, the “absolute position in the three-dimensional space” is a position expressed by a coordinate system set outside the work machine. For example, when GPS is used as a three-dimensional position measuring device. It is a position expressed by a coordinate system fixed to a reference ellipsoid used as a height reference in GPS. In the present specification, the coordinate system set to the reference ellipsoid is referred to as a global coordinate system.

  In order to achieve the above object, a first invention is provided on a vehicle body of a work machine, each of which includes a plurality of three-dimensional position measurement devices that measure absolute positions in a three-dimensional space, and the plurality of three-dimensional position measurements. Position and orientation calculation means for calculating the position and orientation of the work machine in the three-dimensional space and the absolute position of the monitor point set in the work machine using the measurement values of the apparatus, and the calculation result of the position and orientation calculation means In a position measurement system for a work machine having a monitor display device that displays an image of the work machine and terrain information such as a target terrain based on the determination unit, a determination unit that determines an operating state of the work machine, And a smoothing means for smoothing the calculated values of the position and orientation of the work machine calculated by the position and orientation calculation means according to the detection result.

  In a second aspect based on the first aspect, the determination means takes in a signal from a detector that detects the operation of the vehicle body in the work machine, determines whether the vehicle body of the work machine is stationary, and performs the smoothing process. The means smoothes the calculated values of the position and orientation of the work machine calculated by the position and orientation calculation means based on the stationary determination from the determination means.

  Further, according to a third aspect, in the first aspect, the determination means takes in a signal from a detector that detects the operation of the vehicle body of the work machine and the swing body on the vehicle body, and the vehicle body and the turn of the work machine. It is characterized in that the body is stationary, and the smoothing means smoothes the calculated values of the position and orientation of the work machine calculated by the position and orientation calculation means based on the stationary determination from the determination means.

  In a fourth aspect based on the first aspect, the determination means is configured to determine whether the vehicle body and the turn of the work machine are based on the previous measurement value and the current measurement value measured by the plurality of three-dimensional position measurement devices. It is characterized in that the body is stationary, and the smoothing means smoothes the calculated values of the position and orientation of the work machine calculated by the position and orientation calculation means based on the stationary determination from the determination means.

  Further, according to a fifth aspect of the present invention, in the first aspect, the determination means takes in a signal from a detector that detects a vehicle speed in the work machine, determines an operating state of the work machine, and the smoothing means The calculation values of the position and orientation of the work machine calculated by the position and orientation calculation means based on the operating state from the determination means are smoothed.

  Further, a sixth invention is characterized in that, in any one of the first to fifth inventions, the smoothing processing means is a filter processing arithmetic means for performing a low-pass filtering process on a time axis.

  Furthermore, in a seventh aspect based on any one of the first to fifth aspects, the smoothing means is a filter processing arithmetic means for performing a low pass filtering process on a time axis, and the filter processing arithmetic means When the vehicle body of the work machine is in a stationary state based on the determination result of the determination means, low-pass filtering is performed using the first cutoff frequency, and when the vehicle body of the work machine is not in a stationary state, The low-pass filtering process is performed using a second cutoff frequency higher than the first cutoff frequency.

  In addition, in an eighth invention according to any one of the first to fifth inventions, each time the sampling is performed, the smoothing means is equal to the past predetermined number of samples including the sampling data of that time. A moving average process is performed in which the data is averaged and the calculated values are smoothed by using the data as current data.

  According to the present invention, the position and orientation of the work machine in the three-dimensional space and the absolute position of the monitor point set in the work machine are calculated, and when displaying the image of the work machine based on the calculation result, When the vehicle body of the work machine is in a stationary state, display fluctuation can be reduced, and when the vehicle body of the work machine is not in a stationary state, a decrease in display followability can be suppressed, thereby improving work efficiency.

  Embodiments of a position measurement system for a work machine according to the present invention will be described below with reference to the drawings. In this embodiment, the present invention is applied to a crawler excavator as a work machine, and a monitor point is set at the bucket tip of the excavator.

  FIG. 1 is a diagram showing an external appearance of a hydraulic excavator equipped with an embodiment of a position measurement system for a work machine according to the present invention.

  In FIG. 1, reference numeral 1 denotes a hydraulic excavator. The hydraulic excavator 1 is provided on a lower traveling body 2, a lower traveling body 2, and an upper revolving body 3 that forms a vehicle body together with the lower traveling body 2. The front work machine 4 includes a boom 5 provided on the upper swing body 3 so as to be rotatable in the vertical direction, and is provided at the tip of the boom 5 so as to be rotatable in the vertical direction. The arm 6 and a bucket 7 provided at the tip of the arm 6 so as to be rotatable in the vertical direction are driven by expanding and contracting the boom cylinder 8, the arm cylinder 9, and the bucket cylinder 10, respectively. The upper swing body 3 is provided with a cab 11.

  The hydraulic excavator 1 includes an angle sensor 21 that detects a rotation angle (boom angle) between the upper swing body 3 and the boom 5, an angle sensor 22 that detects a rotation angle (arm angle) between the boom 5 and the arm 6, An angle sensor 23 that detects a rotation angle (bucket angle) between the arm 6 and the bucket 7, an inclination sensor 24 that detects an inclination angle (pitch angle) in the front-rear direction of the upper swing body 3, the upper swing body 3 and the lower traveling body 2. An angle sensor 26 for detecting a rotation angle (turning angle) is provided.

  Although not shown in FIG. 1, a pressure sensor 27 (see FIG. 2) that detects a pilot pressure (swing pilot pressure) generated when the upper swing body 3 is turned, and a pilot pressure generated when the lower track 2 is operated. A pressure sensor 28 (see FIG. 2) for detecting (traveling pilot pressure) is provided.

  Further, the excavator 1 includes two GPS antennas 31 and 32 that receive signals from GPS satellites, a wireless antenna 33 that receives correction data (described later) from a reference station, and a wireless antenna 34 that transmits position data. Is provided. The two GPS antennas 31 and 32 are installed on the left and right of the rear part of the revolving unit that is off the turning center of the upper revolving unit 3.

  FIG. 2 is a block diagram showing an overall configuration of an embodiment of a position measurement system for a work machine according to the present invention.

  In FIG. 2, reference numeral 200 denotes an embodiment of the position measurement system of the present invention. A wireless device 41 that receives correction data (described later) from a reference station via an antenna 33, and correction data received by the wireless device 41 is displayed. A distributor 42 that distributes, and a GPS receiver 43 that measures the three-dimensional positions of the GPS antennas 31 and 32 in real time based on correction data from the distributor 42 and signals from GPS satellites received by the GPS antennas 31 and 32. 44, the position data from the GPS receivers 43, 44, the angle sensors 21-23 of the front work machine 4, the angle data from the tilt sensor 24, the turning angle sensor 26, and the pressure data from the pilot pressure sensors 27, 28. , And the position and form of the excavator 1 based on the aggregated data. And a vehicle-mounted computer 46 having a monitor screen 46a for calculating and displaying the position of the tip (monitor point) of the bucket 7, and a radio 47 for transmitting the position data calculated by the vehicle-mounted computer 46 via the antenna 34. I have. The GPS antenna 31 and the GPS receiver 43, and the GPS antenna 32 and the GPS receiver 44 each constitute a set of GPS (Global Positioning System) receivers.

  Here, reference numeral 48 denotes an IC card, which stores original terrain data and target terrain data of a work range planned by a server computer, which will be described later. The operator connects the IC card 48 to the in-vehicle computer 46 when the system is started. Enter the data. At the end of the work, the measurement data is recorded on the IC card 48, connected to the server computer, input the measurement data, and used for construction management.

  FIG. 3 is a block diagram showing an apparatus configuration of an office side system having a role as a GPS reference station related to the position measurement system for work machines according to the present invention.

  In FIG. 3, 51 is an office that manages the position and work of the hydraulic excavator 1 and bucket 7, etc. The office 51 receives a GPS antenna 52 that receives signals from GPS satellites, and correction data is transmitted to the hydraulic excavator 1. From the excavator 1, the radio antenna 54 that receives the position data of the hydraulic excavator 1, the bucket 7, etc. from the excavator 1, the three-dimensional position data measured in advance and the GPS satellite 52 received from the GPS satellite 52 Based on the signal, the GPS receiver 43 and 44 of the excavator 1 described above generates correction data for performing RTK (real-time kinematic) measurement. The wireless device 56 for transmitting the corrected data through the antenna 53 and the antenna 54 Radio 57 for receiving data, the server computer 58 for performing computation and display for displaying and managing the location of the hydraulic excavator 1 and the bucket 7 on the basis of the position data received is established by radio 57. The GPS antenna 52 and the GPS receiver 55 constitute a set of GPS receivers.

  An IC card 48 can be connected to the server computer 58 to input / output original terrain data, target terrain data, measurement data, and the like.

Next, the outline of the operation of the embodiment of the position measurement system of the present invention will be described.
In the present embodiment, in order to perform position measurement with high accuracy, RTK measurement is performed by the GPS receivers 43 and 44 shown in FIG. For this purpose, first, the GPS reference station 55 for generating the correction data shown in FIG. 3 is required. The GPS reference station 55 generates correction data for RTK measurement based on the position data of the GPS antenna 52 measured in advance three-dimensionally as described above and the signal from the GPS satellite received by the GPS antenna 52, The generated correction data is transmitted by the wireless device 56 through the antenna 53 at a constant cycle.

  On the other hand, the GPS receivers 43 and 44 on the vehicle side shown in FIG. 2 are based on correction data received by the wireless device 41 via the antenna 33 and signals from GPS satellites received by the antennas 31 and 32. RTK measurement is performed on the three-dimensional positions of the antennas 31 and 32. By this RTK measurement, the three-dimensional positions of the antennas 31 and 32 are measured with an accuracy of about ± 1 to 2 cm. The measured three-dimensional position data is input to the controller 45.

  Further, the rotation angle of the boom 5, the arm 6 and the bucket 7 by the angle sensors 21 to 23, the pitch angle of the hydraulic excavator 1 by the inclination sensor 24, the rotation angle of the lower traveling body 2 by the turning angle sensor 26, the pilot pressure sensor 27, The turning and traveling pilot pressures are respectively measured by 28 and similarly input to the controller 45.

  The in-vehicle computer 46 includes a storage unit and a calculation unit, performs general vector calculation and coordinate conversion based on various data input to the controller 45, and determines the position and posture of the excavator 1 and the tip of the bucket 7. A three-dimensional position is calculated. Further, based on the obtained three-dimensional position and the terrain data input from the IC card 48, the information is displayed on the monitor screen 46a of the in-vehicle computer 46 to inform the operator of the work status, and the wireless device 47 via the antenna 34. Send.

  The transmitted position and orientation of the excavator 1 and the position data of the tip of the bucket 7 are received by the wireless device 57 via the antenna 54 and input to the server computer 58. The server computer 58 stores the input position and posture of the excavator 1 and the position data of the tip of the bucket 7 and displays them on the monitor screen of the server computer 58. Thereby, the working state of the excavator 1 can be managed in the office 51.

Next, the arithmetic processing in the vehicle-mounted computer 46 which comprises one embodiment of the position measuring system of this invention is demonstrated using FIGS.
FIG. 4 is a diagram showing a coordinate system used for calculating the position and posture of the excavator 1 used in one embodiment of the position measurement system of the present invention and the absolute position of the tip of the bucket 7 in a three-dimensional space. It is. In FIG. 4, Σ0 is a global coordinate system having an origin O0 at the center of a GPS-compliant ellipsoid, Σ3 is fixed to the upper swing body 3 of the hydraulic excavator 1, and the origin O3 is set at the intersection of the swing base frame and the swing center. An upper revolving body coordinate system, Σ7, is a bucket tip coordinate system fixed to the bucket 7 and having a center O7 at the tip of the bucket 7. OC is the intersection of the ground contact surface of the lower traveling body 2 with the ground and the turning center.

  Since the positional relationship Xga, Xgb, Yga, Ygb, Zga, Zgb of the GPS antennas 31 and 32 with respect to the origin (intersection of the turning base frame and the turning center) O3 of the upper turning body coordinate system Σ3 is known, the global coordinate system Σ0 If the three-dimensional positions of the GPS antennas 31 and 32 and the pitch angle θ2 of the hydraulic excavator 1 are known, the position and orientation of the upper swing body coordinate system Σ3 in the global coordinate system Σ0 (the direction of the upper swing body 3) can be obtained. Can do.

  Further, since the positional relationship α3, α4, β4 between the origin O3 of the upper-part turning body coordinate system Σ3 and the base end of the boom 5 and the dimensions α5, α6, α7 of the boom 5, arm 6, and bucket 7 are known, the boom angle If θ5, arm angle θ6, and bucket angle θ7 are known, the position and orientation of bucket tip coordinate system Σ7 in upper swing body coordinate system Σ3 can be obtained.

  Naturally, since the positional relationship αC between the origins O3 and OC of the upper swing body coordinate system Σ3 is known, if the swing angle θSW is known, the position and posture of the lower traveling body 2 in the upper swing body coordinate system Σ3 can be determined. Can be sought.

  Accordingly, the three-dimensional positions of the GPS antennas 31 and 32 obtained by the GPS receivers 43 and 44 on the vehicle side are obtained as values in the global coordinate system Σ0, the pitch angle θ2 of the hydraulic excavator 1 is obtained by the angle sensor 24, and the angle sensor The boom angle θ5, the arm angle θ6, and the bucket angle θ7 are obtained from 21 to 23, the turning angle θSW is obtained by the turning angle sensor 26, and the coordinate conversion calculation is performed, whereby the position and posture of the excavator 1 (the upper turning body 3 The position and orientation, the position and orientation of the lower traveling body 2), and the tip position of the bucket 7 can be obtained from the values of the global coordinate system Σ0.

FIG. 5 is a diagram for explaining the concept of the global coordinate system used in one embodiment of the position measurement system of the present invention.
In FIG. 5, G is a compliant ellipsoid used in GPS, and the origin O0 of the global coordinate system Σ0 is set at the center of the compliant ellipsoid G. Further, the x0 axis direction of the global coordinate system Σ0 is located on a line passing through the intersection C of the equator A and the meridian B and the center of the reference ellipsoid G, and the z0 axis direction is a line extending from the center of the reference ellipsoid G to the north and south. The y0 axis direction is located on a line orthogonal to the x0 axis and the z0 axis. In GPS, the position on the earth is expressed by latitude and longitude, and the height (depth) with respect to the reference ellipsoid G. By setting the global coordinate system Σ0 in this way, the GPS position information is expressed in the global coordinate system. It can be easily converted to a value of Σ0.

FIG. 6 is a flowchart showing a calculation processing procedure of the in-vehicle computer 46 constituting one embodiment of the position measurement system of the present invention.
6, first, the three-dimensional position (latitude, longitude, height) of the GPS antenna 31 obtained by the GPS receiver 43 on the vehicle-mounted side is converted into the value 0P1 of the global coordinate system Σ0 based on the above idea (step S10). ). An arithmetic expression for this is generally well known and is omitted here. Similarly, the three-dimensional position of the GPS antenna 32 obtained by the in-vehicle side GPS receiver 44 is converted into a value 0P2 of the global coordinate system Σ0 (step S20).

  Next, the pitch angle θ2 measured by the tilt sensor 24 is input (step S30), the three-dimensional positions 0P1, 0P2 in the global coordinate system Σ0 of the GPS antennas 31 and 32 obtained in steps S10 and 20 and the pitch angle θ2 thereof. And the positional relationship Xga, Xgb, Yga, Ygb, Zga, Zgb of the GPS antennas 31 and 32 with respect to the origin (intersection of the turning base frame and the turning center) O3 of the upper turning body coordinate system Σ3 stored in the storage device. The position and orientation of the revolving body coordinate system Σ3 are obtained from the value 0Σ3 of the global coordinate system Σ0 (step S40). This calculation is coordinate transformation and can be performed by a general mathematical method.

  Next, the position and posture 0Σ3 of the upper-part turning body coordinate system Σ3 in the global coordinate system Σ0 obtained in step S40 are subjected to low-pass filtering processing (step S50). Details of this processing will be described later.

  Next, the turning angle θSW obtained from the measured value of the turning angle sensor 26 is input, and the posture 3P4 of the lower traveling body 2 with respect to the upper turning body 3 is obtained (step S60). Next, the boom angle θ5, the arm angle θ6, and the bucket angle θ7 detected by the angle sensors 21 to 23 are input, and these values and the origin O3 of the upper-part turning body coordinate system Σ3 and the base end of the boom 5 stored in the storage device are input. The bucket tip position 3P7 is determined in the upper swing body coordinate system Σ3 from the positional relationships α3, α4, β4 and the dimensions α5, α6, α7 of the arms 5, 6 and 7 (step S70). This calculation is also coordinate transformation and can be performed by a general mathematical method.

  Next, the value 0Σ3 of the upper swing body coordinate system Σ3 in the global coordinate system Σ0 filtered in step S50 and the bucket tip position 3P7 in the upper swing body coordinate system Σ3 obtained in step S70 are used in the global coordinate system Σ0. The bucket tip position 0P7 is obtained (step S80).

  Next, the position and orientation of the upper swing body 3 obtained as described above and the attitude 3P4 of the lower traveling body 2 with respect to the upper swing body 3 (hereinafter, the position and attitude of the hydraulic excavator are appropriately referred to as 0Σ3 and 3P4), Display data is created based on each data of the bucket tip position 0P7 and the terrain data input from the IC card 48, and the monitor screen 46a of the in-vehicle computer 46 includes the upper swing body 3 and the bucket 7 and the lower traveling body 2 for the terrain. The positional relationship with the hydraulic excavator 1 is displayed superimposed (step S90). Further, the position and posture of the excavator and the bucket tip position data are transmitted by the radio 47 via the antenna 34, and a similar image is displayed on the monitor screen of the server computer 58.

FIG. 7 shows an example of images displayed on the monitor screen 46a of the in-vehicle computer 46 and the monitor screen of the server computer 58 that constitute one embodiment of the position measurement system of the present invention.
In FIG. 7, reference numeral 100 denotes a terrain such as an original terrain or a target terrain, and the excavator 1 is displayed superimposed on the terrain 100. As a result, the operator can accurately grasp the positional relationship between the terrain and the hydraulic excavator 1 including the bucket 7, and can perform work safely and efficiently.

  FIG. 8 is a flowchart showing details of the low-pass filtering process in step S50 of the flowchart shown in FIG.

  In FIG. 8, first, the turning pilot pressure and the traveling pilot pressure measured by the pressure sensors 27 and 28 are read (steps S51 and S52).

  Next, it is determined whether or not the swing pilot pressure and the traveling pilot pressure are equal to or higher than the threshold values, respectively, and it is determined whether or not the excavator 1 is performing a swing operation or whether or not the hydraulic excavator 1 is performing a travel operation (step S53). ). Here, each threshold value is a value at which the upper turning body 3 starts to move and a value at which the lower traveling body 2 starts to move. By performing the determination in step S53 using such a threshold value, it is possible to determine whether or not the excavator 1 is turning or whether or not the excavator 1 is traveling.

  If the determination result in step S53 is true (the excavator 1 is turning or traveling), the process proceeds to step S54, and the value 0Σ3 of the upper turning body coordinate system Σ3 in the global coordinate system Σ0. A low-pass filtering process with a relatively high cut-off frequency (for example, 5 Hz) is performed for the purpose of removing noise components. As a result, it is possible to improve calculation results and display followability during turning or traveling.

  If the determination result in step S53 is false (the excavator 1 is neither turning nor running), the process proceeds to step S55, where the value 0Σ3 of the upper turning body coordinate system Σ3 in the global coordinate system Σ0. On the other hand, a low-pass filtering process with a relatively low cutoff frequency (for example, 1 Hz) is performed for the purpose of suppressing fluctuations in the monitor display. Thereby, variation in the calculation result when the work machine is stopped or only the front work machine 4 is operating can be reduced, and display fluctuation can be reduced.

  In the above, the GPS antennas 31 and 32 and the GPS receivers 43 and 44, the wireless antenna 33 and the wireless device 41 are installed on the vehicle body (the lower traveling body 2 and the upper turning body 3) of the hydraulic excavator 1 which is a work machine. A plurality of three-dimensional position measuring devices that measure absolute positions in a three-dimensional space are configured, and the processing functions of steps S10 to S40 and steps S60 to S80 of the flowchart shown in FIG. A position and orientation calculation means for calculating the position and orientation of the work machine in the three-dimensional space and the absolute position of the monitor point (bucket tip) set in the work machine using the measurement value of the three-dimensional position measurement device, The processing function and monitor screen 46a of step S90 in the flowchart shown in FIG. Configuring the monitor display device for displaying the topographical information such as the work machine and the target topography on the basis of the calculation results. Further, the pressure sensor 27 for detecting the turning pilot pressure and the pressure sensor 28 for detecting the traveling pilot pressure constitute an operation detecting means for detecting the operation state of the work machine, and step S50 of the flowchart shown in FIG. The processing function (steps S51 to S55 in FIG. 8) is a smoothing processing means for smoothing the calculated values of the position and orientation of the work machine calculated by the position and orientation calculation means according to the detection result of the motion detection means. Constitute.

Next, the operation and effect of the embodiment of the position measurement system for the industrial machine according to the present invention described above will be described.
In the position measurement system for a work machine such as a hydraulic excavator according to the present invention, in order to calculate the position of the bucket 7 in the three-dimensional space, each GPS reception is performed based on the signals received by the two GPS antennas 31 and 32. The positions of the two GPS antennas 31 and 32 (two positions on the upper swing body 3 where the two GPS antennas 31 and 32 are located) are measured by RTK using the machines 43 and 44, and the measured upper swing body 3, a vehicle body coordinate system (upper revolving body coordinate system 0Σ3) representing the position and posture of the excavator 1 is obtained from the positions of two points on the angle 3, and the angle sensors 21, 22 attached to the boom 5, the arm 6 and the bucket 7 are obtained. The absolute position (bucket tip position 0P7) in the three-dimensional space of the bucket 7 is calculated by combining the angle information of 23 and the like.

  By the way, in RTK measurement performed using GPS, which is a three-dimensional position measurement device, ± 1 to 2 cm depending on the location of captured GPS satellites and the influence of the ionosphere, even in the normal measurement state (FIX) Since the measurement results vary in the range, naturally, the vehicle coordinate system values calculated based on the GPS measurement results also vary. When the calculation is performed using a plurality of (two) GPS as in the position measurement system according to the present invention, the variation of the measurement result has a greater influence on the calculation result, and the vehicle body (the lower traveling body is not operated without operating the operation lever). Even when the 2 and the upper swing body 3) are stationary, the hydraulic excavator 1 displayed on the monitor screen 46a of the in-vehicle computer 46 will be displayed in a flickering manner.

  In actual work such as excavation, a work machine such as a hydraulic excavator often works by operating only the front work machine 4 with the vehicle body (the lower traveling body 2 and the upper swing body 3) stationary. In this case, if the image of the hydraulic excavator 1 displayed on the monitor screen 46a is fluctuated due to variations in GPS measurement values even though the turning operation or the traveling operation is not performed, it becomes difficult to align the position. This leads to a decrease in work efficiency such as misrecognizing the relationship.

  For example, in the slope excavation work, the positional relationship of the bucket with respect to the target terrain is confirmed while looking at the target terrain (target slope) displayed on the monitor screen 46a and the bucket symbol, and the target terrain (target slope) is formed. Excavation is performed by operating the bucket 7. In such an operation, if the image of the hydraulic excavator 1 fluctuates and is displayed on the monitor screen 46a, it may take a long time for alignment or excavate a place different from the target landform.

  Further, in the work for confirming the current position after moving the excavator, when the excavator is moved and stopped, the positional relationship of the current excavator with respect to the surrounding terrain is displayed on the monitor screen 46a and the excavator symbol. Confirm and grasp by. In this case as well, if the image of the hydraulic excavator 1 is displayed on the monitor screen 46a, it may take time to confirm the positional relationship with respect to the surrounding terrain, or may stop at a place different from the target.

  In the present embodiment, as described above, it is determined whether or not the excavator 1 is turning, or whether or not the excavator 1 is running (step S53). When neither movement operation is performed, a relatively low cutoff frequency (for example, for the purpose of suppressing fluctuations in the monitor display with respect to the value 0Σ3 of the upper swing body coordinate system Σ3 in the global coordinate system Σ0) A low-pass filtering process using 1 Hz) is performed (step S55). As a result, variations in the calculation results of the position and orientation of the hydraulic excavator 1 when the hydraulic excavator 1 is stopped or only the front work machine 4 is operating can be reduced, and display fluctuation can be reduced. When checking the current position after slope excavation work or excavator movement, the visibility on the monitor screen 46a is improved, and it is easy to check and grasp the position of the bucket blade and the positional relationship with the surrounding terrain. Can be improved.

  Here, in the low-pass filtering process, when the cut-off frequency is set low, the calculation result and the display followability deteriorate. However, in the work performed with the vehicle body (the lower traveling body 2 and the upper swing body 3) being stationary, an adverse effect due to a decrease in the calculation result and the followability of the display hardly occurs, and the visibility is improved by reducing the display fluctuation. The merit by is greater.

  On the other hand, in an operation performed while the vehicle body (the lower traveling body 2 and the upper revolving body 3) is moved, such as during traveling or turning, an operation performed while the vehicle body (the lower traveling body 2 and the upper revolving body 3) is stationary. Similarly, when low-pass filtering processing is performed using a low cutoff frequency (for example, 1 Hz), the calculation results regarding the position and orientation and the followability of the display deteriorate, and the display on the monitor screen 46a is delayed. As a result, there is a delay in grasping the positional relationship of the work machine (vehicle body) with respect to the work efficiency.

  For example, during the traveling of the excavator 1, during the traveling of the excavator 1, the positional relationship between the excavator 1 and the surrounding terrain is confirmed and grasped by the terrain data and the excavator symbol displayed on the monitor screen 46a. Further, in the turning work, while the upper turning body 3 is turning, the positional relationship between the front work machine 4 and the surrounding terrain is confirmed and grasped by the terrain data and the hydraulic excavator symbol displayed on the monitor screen 46a. In this case, if a delay occurs in the display on the monitor screen 46a, the actual positional relationship of the hydraulic excavator 1 or the front working machine 4 with respect to the surrounding terrain and the positional relationship on the display are shifted, and the vehicle is traveling or turning. Alignment with the target terrain (surrounding terrain) is reduced.

  In the present embodiment, as described above, it is determined whether or not the excavator 1 is turning, or whether or not the excavator 1 is running (step S53), and the excavator 1 turns. Or, when the vehicle is running, a low-pass with a relatively high cut-off frequency (for example, 5 Hz) for the purpose of removing noise components with respect to the value 0Σ3 of the upper-part turning body coordinate system Σ3 in the global coordinate system Σ0. A filtering process is performed (step S54). As a result, the follow-up of calculation results and display during turning or running improves, so that the positional relationship between the excavator 1 and the surrounding terrain can be grasped without delay in the position checking work and turning work as described above. In addition, the alignment property between the hydraulic excavator 1 and the target landform is improved, and as a result, work efficiency can be improved.

  In addition, the display wobbling may be a problem even when the vehicle is running or turning. For example, during traveling such as moving on a thin single road, if the display fluctuates, the work machine will be displayed outside the road. In this embodiment, even when the vehicle is running or turning, low-pass filtering processing with a relatively high cutoff frequency (for example, 5 Hz) is performed for the purpose of removing noise components, thereby ensuring display followability. However, the display wobbling can be reduced to some extent, and the work machine can also improve the display performance with respect to the target landform (road).

  As described above, according to the present embodiment, the position and orientation of the work machine in the three-dimensional space and the absolute position of the monitor point set on the work machine are calculated, and the image of the work machine is calculated based on the calculation result. When the machine body of the work machine is stationary, the display fluctuation is reduced.When the machine body of the work machine is not stationary, the decrease in the follow-up performance of the display is suppressed. Can be improved.

  FIG. 9 is a flowchart showing details of low-pass filtering processing in another embodiment of the position measurement system of the present invention. In FIG. 9, the same reference numerals as those in FIG. 8 denote the same steps.

  In this embodiment, whether or not the work machine moves (runs the vehicle body or turns the upper-part turning body) in the low-pass filtering process during the calculation processing procedure of the in-vehicle computer 46 constituting the embodiment of the position measurement system of the present invention. This determination process is performed based on the amount of movement of the positions of the two GPS antennas 31 and 32. In other words, in FIG. 9, the in-vehicle computer 46 obtains the movement distance L1 from the value one cycle before and the current value of the position (OP1) of the GPS antenna 31 in the global coordinate system (step S51).

  Next, the movement distance L2 is obtained from the value one cycle before the position (OP2) in the global coordinate system of the GPS antenna 32 and the current value (step S52).

  Next, whether or not the movement distances L1 and L2 are equal to or greater than a threshold value is compared to determine whether or not the excavator 1 is turning or whether or not the excavator 1 is running (step S53). ). Here, each threshold value sets the measurement accuracy (for example, 2 cm) in the RTK-GPS FIX state. Here, this threshold value is a value at which the upper turning body 3 starts to move and a value at which the lower traveling body 2 starts to move. By performing the determination in step S53 using such a threshold value, it is possible to determine whether or not the excavator 1 is turning or whether or not the excavator 1 is traveling.

  Thereafter, similarly to the process shown in FIG. 8 described above, if the determination result in step S53 is true (the hydraulic excavator 1 is performing a turning operation or a traveling operation), the process proceeds to step S54 and the global coordinate system Σ0 A low-pass filtering process with a relatively high cut-off frequency (for example, 5 Hz) for the purpose of removing noise components is performed on the value 0Σ3 of the upper swing body coordinate system Σ3. As a result, it is possible to improve calculation results and display followability during turning or traveling.

  If the determination result in step S53 is false (the excavator 1 is neither turning nor running), the process proceeds to step S55, where the value 0Σ3 of the upper turning body coordinate system Σ3 in the global coordinate system Σ0. On the other hand, a low-pass filtering process with a relatively low cutoff frequency (for example, 1 Hz) is performed for the purpose of suppressing fluctuations in the monitor display. Thereby, variation in the calculation result when the work machine is stopped or only the front work machine 4 is operating can be reduced, and display fluctuation can be reduced.

  According to this embodiment, as in the above-described embodiment, the display fluctuation is reduced when the vehicle body of the work machine is stationary, and the display is followed when the vehicle body of the work machine is not stationary. It is possible to suppress the deterioration of the performance and to improve the work efficiency. Further, since it is not necessary to take in a signal from a detector that detects the operating state of the work machine, it is possible to omit wiring for that purpose.

  The embodiment described above can be variously modified within the spirit of the present invention. Some of the modifications will be described below.

<Modification 1>
In the above embodiment, in the low-pass filtering process of step S50 in the calculation processing procedure of the in-vehicle computer 46 shown in FIG. 6, whether or not the excavator 1 is turning as shown in FIGS. Alternatively, it is determined whether or not the excavator 1 is traveling (step S53), and if the determination result is true (the excavator 1 is turning or traveling), the global coordinate system Σ0 A low-pass filtering process with a relatively high cut-off frequency (for example, 5 Hz) for the purpose of removing noise components was performed on the value 0Σ3 of the upper swing body coordinate system Σ3 at (Step S54).

  However, in the process of step S54, the low-pass filtering process is not performed, and the value 0Σ3 of the upper swing body coordinate system Σ3 in the global coordinate system Σ0 is used as it is in step S80 of FIG. 6, and the bucket tip position in the global coordinate system Σ0 is used. 0P7 may be obtained.

  In the present invention, the main purpose of performing the low-pass filtering process (smoothing process) is a state in which the vehicle body is stationary, such as when the vehicle body (the lower traveling body 2 and the upper turning body 3) is stationary and the work is performed only by the front work machine 4. This is to prevent the image of the hydraulic excavator displayed on the monitor screen 46a of the vehicle-mounted computer 46 from being staggered. Also in this modification, in step S55 of FIG. 8, when the excavator 1 is neither turning nor running (the vehicle body is stationary), the upper turning body coordinate system Σ3 in the global coordinate system Σ0. By performing a low-pass filtering process with a relatively low cut-off frequency (for example, 1 Hz) for the purpose of suppressing fluctuations in the monitor display with respect to the value 0Σ3, it is possible to reduce calculation results and display variations. Can serve that purpose. Further, when the excavator 1 is turning or running (the vehicle body is not in a stationary state), the low-pass filtering process is not performed, so that the followability of the calculation result and the display can be improved.

<Modification 2>
In the above embodiment, the low-pass filtering process is performed on the value 0Σ3 of the upper swing body coordinate system Σ3 in the global coordinate system Σ0 in step S50 in the calculation processing procedure of the in-vehicle computer 46 shown in FIG. S54, S55). However, the low-pass filtering process is an example of a smoothing process, and other smoothing processes may be performed. As another smoothing process, for example, there is a moving average process. The moving average process is a process that averages the data of the past predetermined number of samples including the sampling data of each time, and smoothes the calculated value by using it as the current data each time sampling is performed. The smoothness can be changed by increasing or decreasing the number of samplings to be averaged.

  For example, during turning or running that does not require high smoothness (when the vehicle body is not stationary), the number of samples is reduced (for example, about 2), and other than turning or running that requires high smoothness In the case of (when the vehicle body is stationary), the number of samples is increased (for example, about 10), and the data corresponding to the number of samples is averaged and used as current data. As a result, the smoothing process can be performed so that the smoothness is higher when the body of the excavator 1 is stationary than when it is not stationary. The fluctuation of the image of the hydraulic excavator displayed on the monitor screen 46a of the computer 46 can be prevented, and when the vehicle body is not in a stationary state, the calculation result and display followability can be improved.

  In this case as well, when the vehicle body is not stationary, smoothing processing (moving average processing) may not be performed.

<Modification 3>
In the above embodiment, the present invention is applied to the position measurement system of a hydraulic excavator. However, the present invention can also be applied to other work machines as long as the vehicle body is provided. Examples of other work machines equipped with a vehicle body include a wheeled excavator, a crane vehicle, a wheel loader, a bulldozer, a telehandler, and a mine disposal machine. A wheeled excavator, a crane vehicle, etc. have a swivel on the vehicle body in the same way as a hydraulic excavator, and the same effect as when applied to a hydraulic excavator can be obtained. Wheel loaders, bulldozers, telehandlers, etc. do not have a swivel, but display smoothing can be prevented by performing smoothing processing with high smoothness during non-traveling work, and work efficiency can be improved. As a landmine disposer, for example, a modified hydraulic excavator as described in JP-A-2004-239666 is known, and by applying the present invention to such a landmine disposer position measurement system, Fluctuation of the display on the monitor screen is prevented, and landmine removal work can be performed appropriately and safely when the vehicle is stationary while viewing the display.

  10 to 13 show an example in which one embodiment of the position measurement system for a work machine according to the present invention is applied to a wheel loader. FIG. 10 shows a wheel loader equipped with the position measurement system according to this embodiment. It is a figure which shows the external appearance. In FIG. 10, reference numeral 101 denotes a wheel loader. The wheel loader 101 includes a vehicle body 102, a driver's cab 103 provided on the vehicle body 12, and tires 104 (104 FL: front left, 104 FR: provided on a side portion of the vehicle body 102. Front right, 104RL: rear left, 104RR: rear right), and a front work machine 105 provided on the rear side of the vehicle body 101.

  The front work machine 105 includes an arm 106 provided at the front end of the front work machine, a bucket 107 provided rotatably at the front end of the arm 106, and a cylinder 108 for rotating the arm 106 and the bucket 107. , 109, and the front work machine 105 is rotatable with respect to the vehicle body 102 by a cylinder 110 (not shown).

  Here, the arm 106 includes a pair of left and right arms 106L (left side) and 106R (right side), and the cylinder 18 that rotates the arm 106 is also configured by 108L (left side) and 108R (right side), respectively. The bucket 107 is rotated by a cylinder 109 via a bell crank 110.

  Further, the wheel loader 101 includes a vehicle speed sensor 111 (not shown, which will be described later) for measuring the vehicle speed incorporated in the transmission, and an angle for detecting a turning angle (steering angle) between the vehicle body 102 and the front work machine 105. A sensor 112 (not shown), an angle sensor 113 that detects a rotation angle (arm angle) between the front work machine 105 and the arm 106, and a rotation angle (bucket angle) between the arm 106 and the bucket 107 are detected. An angle sensor 114 and an inclination sensor 115 (not shown) for detecting an inclination angle (pitch angle) in the front-rear direction of the vehicle body 102 are provided.

  Furthermore, the wheel loader 101 includes two GPS antennas 31 and 32 that receive signals from GPS satellites, a wireless antenna 33 that receives correction data from a reference station, and a wireless antenna 34 that transmits position data. Is provided.

FIG. 11 is a block diagram showing an overall configuration of an embodiment of a position measurement system for a work machine according to the present invention mounted on a wheel loader 101. In FIG. 11, the same reference numerals as those in FIGS. 10 and 2 denote the same or corresponding parts.
In FIG. 11, reference numeral 200 denotes a position measurement system according to the present invention, which includes a radio 41 that receives correction data from a reference station via an antenna 33, a distributor 42 that distributes correction data received by the radio 41, and a distribution. GPS receivers 31 and 32 that measure the three-dimensional positions of the GPS antennas 1025 and 1026 in real time based on correction data from the machine 42 and signals from GPS satellites received by the GPS antennas 1025 and 1026, and the GPS receivers The position data from 31 and 32 and the angle data from the angle sensors 112 to 114 of the front work machine 105 and the angle data from the inclination sensor 115 are input, and the controller 45 for collecting and the position of the wheel loader 101 based on these collected various data. And calculate the position and position of the tip of the bucket 107 (monitor point) , And a radio 47 for transmitting vehicle computer 46 having a monitor screen 46a for displaying the position data calculated by the onboard computer 46 via the antenna 34.

  Here, 48 is an IC card, which stores original terrain data, target terrain data, etc. of the work range planned by the server computer, and the operator connects the IC card 48 to the in-vehicle computer 46 when the system is started. Enter. At the end of the work, the measurement data is recorded on the IC card 48, connected to the server computer, input the measurement data, and used for construction management.

  In addition, regarding the coordinate system and calculation procedure of the position and posture of the wheel loader 101 and the position of the tip (monitor point) of the bucket 107 in this embodiment, it is only necessary to consider up to the body 102 portion, and the lower traveling body in FIG. If the tires, the upper turning body are replaced with the vehicle body, and the upper turning body coordinate system Σ3 is replaced with the vehicle body coordinate system Σ3, the calculation can be performed in the same manner, and the description thereof will be omitted.

FIG. 12 is a flowchart showing details of the low-pass filtering process.
In FIG. 12, the same reference numerals as those in FIG. 8 denote the same steps. First, the vehicle body speed BDv measured by the vehicle speed sensor 111 is read (step S121).

  Next, it is determined whether the vehicle body speed BDv is equal to or higher than the first threshold value (step S122).

  Here, the first threshold is set to 10 km / h, for example. By performing the determination in step S122 using such a threshold value, it can be determined whether or not the wheel loader 1001 is traveling at a high speed.

  If the determination result in step S122 is true (the wheel loader 101 is traveling at high speed), the process proceeds to step S121, and the noise component of the value 0Σ3 of the vehicle body coordinate system Σ3 in the global coordinate system Σ0 is detected. A low-pass filtering process with a relatively high cutoff frequency (for example, 5 Hz) is performed for the purpose of removal. Thereby, it is possible to improve calculation results and display followability during high-speed traveling.

  If the determination result in step S122 is false (the wheel loader 101 is not traveling at high speed), the process proceeds to step S123, where it is determined whether the vehicle body speed BDv is equal to or higher than the second threshold value.

  Here, the second threshold is set to 0.1 km / h, for example. By performing the determination in step S1304 using such a threshold value, it can be determined whether or not the wheel loader 1 is traveling at a low speed.

  If the determination result in step S123 is true (the wheel loader 101 is traveling at a low speed), the process proceeds to step S124, and the noise component is compared with the value 0Σ3 of the vehicle body coordinate system Σ3 in the global coordinate system Σ0. A low-pass filtering process with a medium cutoff frequency (for example, 3 Hz) is performed for the purpose of removal. Thereby, it is possible to improve the calculation result and display followability during low-speed traveling.

  On the other hand, if the determination result in step S123 is false (the wheel loader 101 is not traveling or is traveling at an extremely low speed), the process proceeds to step S125, and the value 0Σ3 of the vehicle body coordinate system Σ3 in the global coordinate system Σ0. On the other hand, a low-pass filtering process with a relatively low cutoff frequency (for example, 1 Hz) is performed for the purpose of suppressing fluctuations in the monitor display. Thereby, variation in the calculation result when the work machine is not traveling can be reduced, and display fluctuation can be reduced.

FIG. 13 is a flowchart showing details of the low-pass filtering process.
In FIG. 13, the same reference numerals as those in FIG. 8 denote the same steps. First, the movement distances L1 and L2 of the GPS antenna 31 and the GPS antenna 32 are respectively the values before and 1 cycle before the position 0P1 in the global coordinate system, and the values 1 cycle before the position 0P2 in the global coordinate system. It calculates | requires from the present value (step S51, S52).

  Next, it is determined whether or not the movement distances L1 and L2 are each greater than or equal to the first threshold (step S131).

  Here, the first threshold is set to several tens of centimeters, for example. By performing the determination in step S131 using such a threshold value, it is possible to determine whether or not the wheel loader 101 is traveling at a high speed.

  If the determination result in step S131 is true (the wheel loader 101 is traveling at a high speed), the process proceeds to step S54, and the noise component is compared with the value 0Σ3 of the vehicle body coordinate system Σ3 in the global coordinate system Σ0. A low-pass filtering process with a relatively high cutoff frequency (for example, 5 Hz) is performed for the purpose of removal. Thereby, it is possible to improve calculation results and display followability during high-speed traveling.

  If the determination result in step S131 is false (the wheel loader 101 is not traveling at high speed), the process proceeds to step S132, and it is determined whether the movement distances L1 and L2 are each greater than or equal to the second threshold value.

  Here, the second threshold value sets the measurement accuracy (for example, 2 cm) in the RTK-GPS FIX state. By performing the determination in step S132 using such a threshold value, it is possible to determine whether or not the wheel loader 1 is traveling at a low speed.

  If the determination result in step S132 is true (the wheel loader 101 is traveling at a low speed), the process proceeds to step S133, and the noise component is compared with the value 0Σ3 of the vehicle body coordinate system Σ3 in the global coordinate system Σ0. A low-pass filtering process with a medium cutoff frequency (for example, 3 Hz) is performed for the purpose of removal. Thereby, it is possible to improve the calculation result and display followability during low-speed traveling.

  On the other hand, if the determination result in step S132 is false (the wheel loader 101 is not traveling or is traveling at an extremely low speed), the process proceeds to step S134 and the value 0Σ3 of the vehicle body coordinate system Σ3 in the global coordinate system Σ0. On the other hand, a low-pass filtering process with a relatively low cutoff frequency (for example, 1 Hz) is performed for the purpose of suppressing fluctuations in the monitor display. Thereby, variation in the calculation result when the work machine is not traveling can be reduced, and display fluctuation can be reduced.

  According to this embodiment, as described above, it is determined whether or not the wheel loader 101 is traveling (low speed, including high speed determination). If the wheel loader 101 is not traveling, the global coordinate system Σ0 is used. A low-pass filtering process using a relatively low cut-off frequency (for example, 1 Hz) for the purpose of suppressing fluctuations in the monitor display is performed on the value 0Σ3 of the vehicle body coordinate system Σ3. As a result, variation in the calculation result of the position and orientation of the wheel loader 101 when the wheel loader 101 is not traveling can be reduced, and the display fluctuation can be reduced. Therefore, the visibility on the monitor screen 46a is improved, and the bucket This makes it easy to check the position of the blade tip, check the surrounding terrain, and the positional relationship with surrounding machines such as dump trucks, and improve work efficiency.

  Further, when the wheel loader 101 is traveling at a low speed, the fluctuation in the monitor display is suppressed to some extent with respect to the value 0Σ3 of the vehicle body coordinate system Σ3 in the global coordinate system Σ0, while removing noise components. A target low-pass filtering process using a medium cut-off frequency (for example, 3 Hz) is performed. As a result, variation in the calculation result of the position and orientation of the wheel loader 101 and fluctuation of display when the wheel loader 1001 is traveling at low speed can be reduced to some extent, and tracking of calculation and display can be secured to some extent. It is easy to check and grasp the positional relationship when approaching a truck, and work efficiency can be improved.

  Further, when the wheel loader 101 is traveling, a relatively high cutoff frequency (for example, 5 Hz) for the purpose of removing noise components with respect to the value 0Σ3 of the vehicle body coordinate system Σ3 in the global coordinate system Σ0. The low pass filtering process is performed. This improves the follow-up of calculation results and display during traveling, so that the positional relationship between the wheel loader 101 and the surrounding terrain can be grasped without delay in the position confirmation operation during traveling. Matchability is improved, and as a result, work efficiency can be improved.

  Of course, in this embodiment, the first and second modifications can be applied.

It is a figure which shows the external appearance of the hydraulic shovel carrying one embodiment of the position measuring system of this invention. It is a block diagram which shows the apparatus structure of one Embodiment of the position measurement system of this invention. It is a block diagram which shows the apparatus structure of the office side system which also has a role as a reference | standard station relevant to one Embodiment of the position measurement system of this invention. It is a figure which shows the coordinate system used in order to calculate the position and attitude | position of the hydraulic shovel used for one embodiment of the position measurement system of this invention, and the absolute position in the three-dimensional space of a bucket front-end | tip. It is a figure explaining the outline | summary of the global coordinate system used for one embodiment of the position measurement system of this invention. It is a flowchart figure which shows the arithmetic processing procedure of the vehicle-mounted computer which comprises one Embodiment of the position measurement system of this invention. It is a figure which shows an example of the image displayed on the monitor screen of the vehicle-mounted computer and server computer which comprise one Embodiment of the position measurement system of this invention. It is a flowchart figure which shows the detail of the low-pass filtering process in one Embodiment of the position measurement system of this invention. It is a flowchart figure which shows the detail of the low-pass filtering process in other embodiment of the position measurement system of this invention. It is a figure which shows the external appearance of the wheel loader carrying one embodiment of the position measuring system of this invention. It is a block diagram which shows the whole structure of one Embodiment of the position measuring system of the working machine of this invention mounted in the wheel loader shown in FIG. It is a flowchart figure which shows the detail of the low-pass filtering process in one Embodiment of the position measurement system of this invention shown in FIG. It is a flowchart figure which shows the detail of the low-pass filtering process in other embodiment of the position measurement system of this invention shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hydraulic excavator 2 Lower traveling body 3 Upper turning body 4 Front work machine 5 Boom 6 Arm 7 Bucket 21-23 Angle sensor 24 Inclination sensor 26 Turning angle sensor 27 Turning pilot pressure sensor 28 Traveling pilot pressure sensor 31, 32 GPS antenna 33, 34 Radio antenna 41 Radio 43, 44 GPS receiver 45 Controller 46 On-board computer 46a Monitor screen (display screen)
47 Radio 48 IC card 51 Office 52 GPS antenna 53, 54 Radio antenna 55 GPS receiver 56, 57 Radio 58 Server computer

Claims (8)

  A plurality of three-dimensional position measuring devices that are installed on the body of the work machine and each measure an absolute position in the three-dimensional space, and work in the three-dimensional space using the measurement values of the plurality of three-dimensional position measuring devices. Position / orientation calculation means for calculating the absolute position of the monitor point set on the work machine and the position of the machine, and terrain information such as the image of the work machine and the target terrain based on the calculation result of the position / orientation calculation means In a position measurement system for a work machine having a monitor display device that displays the above, a determination unit that determines an operation state of the work machine, and a work that is calculated by the position and orientation calculation unit according to a detection result of the determination unit A position measurement system for a working machine, comprising: smoothing processing means for smoothing the calculated values of the position and orientation of the machine.   2. The position measurement system for a work machine according to claim 1, wherein the determination means takes in a signal from a detector that detects the operation of the vehicle body in the work machine, determines whether the vehicle body of the work machine is stationary, and the smoothing processing means. Is a position measurement system for a work machine that smoothes the calculated values of the position and orientation of the work machine calculated by the position / orientation calculation means based on the stationary determination from the determination means.   2. The position measurement system for a work machine according to claim 1, wherein the determination means takes in a signal from a detector for detecting the operation of the vehicle body of the work machine and the swing body on the vehicle body, and the vehicle body and the swing body of the work machine. The smoothing means smoothes the calculated values of the position and orientation of the work machine calculated by the position and orientation calculation means based on the stillness determination from the determination means. Position measurement system.   2. The work machine position measurement system according to claim 1, wherein the determination unit is configured to determine a vehicle body and a swing body of the work machine based on a previous measurement value and a current measurement value measured by the plurality of three-dimensional position measurement devices. The smoothing means smoothes the calculated values of the position and orientation of the work machine calculated by the position and orientation calculation means based on the stillness determination from the determination means. Position measurement system.   2. The work machine position measurement system according to claim 1, wherein the determination unit takes in a signal from a detector that detects a vehicle speed in the work machine, determines an operating state of the work machine, and the smoothing processing unit includes: A position measurement system for a work machine that smoothes the calculated values of the position and posture of the work machine calculated by the position / orientation calculation means based on an operating state from the determination means.   The work machine position measuring system according to any one of claims 1 to 5, wherein the smoothing means is a filter processing operation means for performing a low-pass filtering process on a time axis. Measuring system.   The position measurement system for a work machine according to any one of claims 1 to 5, wherein the smoothing processing unit is a filter processing calculation unit that performs a low-pass filtering process on a time axis, and the filter processing calculation unit includes: When the vehicle body of the work machine is in a stationary state based on the determination result of the determination means, low-pass filtering is performed using the first cutoff frequency, and when the vehicle body of the work machine is not in a stationary state, A position measurement system for a work machine that performs low-pass filtering using a second cutoff frequency that is higher than the first cutoff frequency.   6. The position measurement system for a work machine according to claim 1, wherein the smoothing means is equivalent to a predetermined number of past samples including sampling data each time sampling is performed. A position measurement system for a work machine, characterized by performing a moving average process that averages data and uses the current data as a smoothing for a calculation value.

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