Work machinery

Abstract

To provide a work machine capable of achieving the efficiency of the whole construction by supporting work arrangement by appropriately providing a user of the work machine with information relating to the positioning accuracy of a GNSS.SOLUTION: A work machine is provided with a controller for calculating a distance between a work target surface acquired from design data and a work tool provided at a tip of the work machine on the basis of a calculation result of a position measurement device and attitude information from an attitude information measurement device. The controller divides a construction site into a plurality of areas on the basis of the design data, sets a representative position about each of the plurality of divided areas, calculates measurement accuracy by the position measurement device about each of representative positions of the plurality of areas on the basis of orbit information on a positioning satellite, topographic data, and structure data, and generates a positioning reliability map showing the positioning accuracy and each of the representative positions of the plurality of areas in association with each other.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a work machine. [Background technology]

[0002] In construction machines that support information-based construction, such as hydraulic excavators, for example, GNSS is used to measure the position coordinates of its own machine in the Earth coordinate system. Because some of the positioning satellites used in GNSS orbit the Earth, the accuracy of GNSS position measurements changes from moment to moment due to changes in the position of the positioning satellites. In addition, GNSS position measurements contain various error factors. Therefore, when a system that uses GNSS provides location information to users, it is also necessary to provide information related to the reliability of the positioning to the user.

[0003] The following is known as a conventional technique for providing a user with the reliability of positioning information using GNSS. For example, Patent Document 1 discloses a navigation device equipped with a satellite positioning unit that performs satellite positioning based on radio waves received from a satellite, the navigation device comprising: a current position calculation means that calculates a current position based on a position determined by the satellite positioning unit during a period when the satellite positioning unit is capable of performing satellite positioning; a current position estimation means that calculates an estimated current position during a period when the satellite positioning unit is unable to perform satellite positioning, at least until the estimated current position reaches an intersection; and a guide image display means that displays a guide image on a map in which a mark indicating the current position of the navigation device is placed, the current position estimation means sequentially calculates the estimated current position from the current position calculated by the current position calculation means immediately before the satellite positioning unit becomes unable to perform satellite positioning, and displays the estimated current position on a road where the current position calculated by the current position calculation means immediately before the satellite positioning unit becomes unable to perform satellite positioning is located. at a predetermined moving speed in the direction of travel immediately before the satellite positioning unit becomes unable to perform satellite positioning, and the guide image display means, during a period when the satellite positioning unit is able to perform satellite positioning, places the mark on the map at a position corresponding to the current position calculated by the current position calculation means, during a period after the satellite positioning unit becomes unable to perform satellite positioning and until the estimated current position calculated by the current position estimation means reaches an intersection, places the mark on the map at a position corresponding to the estimated current position calculated by the current position estimation means, and during a period after the estimated current position calculated by the current position estimation means reaches an intersection, during a period when the satellite positioning unit is unable to perform satellite positioning, places the mark on the map at a position corresponding to the intersection reached. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-137313 Summary of the Invention [Problem to be solved by the invention]

[0005] In information-based construction, the accuracy of construction work by hydraulic excavators and other work machines is significantly affected by positioning accuracy. Therefore, when users of work machines plan their work, they must take the machine's positioning accuracy into consideration. However, because the accuracy of GNSS positioning varies depending on the location of the work machine and positioning satellites at the work site, as well as the work site environment, it is not easy to properly plan the work. Furthermore, if the work plan cannot be properly planned, there is a concern that the efficiency of the entire construction work will decrease.

[0006] The present invention has been made in consideration of the above, and aims to provide a work machine that can assist in work planning by appropriately providing information related to GNSS positioning accuracy to the user of the work machine, thereby improving the efficiency of the entire construction work. [Means for solving the problem]

[0007] The present application includes a plurality of means for solving the above-mentioned problems, and one example thereof is a construction method and apparatus for carrying out the construction work at a construction site, comprising: a lower traveling body; an upper rotating body rotatably provided on the lower traveling body and constituting a vehicle body together with the lower traveling body; a working device configured by rotatably connecting a plurality of driven members including a working implement to each other and rotatably supported on the upper rotating body; an attitude information measuring device that measures attitude information of the upper rotating body and the plurality of driven members; a position measuring device that calculates the position and orientation of the vehicle body at the construction site based on a navigation signal from a positioning satellite; and a design design that is a target shape of the construction site based on the calculation result from the position measuring device and the attitude information from the attitude information measuring device. In a construction machine equipped with a controller that calculates the distance between a work target surface obtained from design data and a work implement attached to the tip of the work device, the controller divides the construction site into a plurality of areas based on the design data, sets a representative position for each of the divided areas, calculates the positioning accuracy of the position measuring device for each of the representative positions of the plurality of areas based on the orbital information of the positioning satellite, topographical data of the surrounding area including the construction site, and structure data that indicates the positions and shapes of structures included in the range of the topographical data, and generates a positioning reliability map that shows the positioning accuracy and each representative position of the plurality of areas in association with each other. [Effects of the Invention]

[0008] According to the present invention, by appropriately providing information related to the GNSS positioning accuracy to the user of the work machine, it is possible to support the work arrangements and improve the efficiency of the entire construction work. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram schematically illustrating the appearance of a hydraulic excavator, which is an example of a work machine. [Figure 2] FIG. 2 is a functional block diagram illustrating the relevant configuration of a machine guidance system extracted from the control system that controls the overall operation of the hydraulic excavator. [Figure 3] FIG. 1 is a diagram illustrating an example of an external system that functions as a reference station. [Figure 4] FIG. 2 is a functional block diagram illustrating the processing functions of the machine guidance unit together with related configurations including some functions of the GNSS receiver. [Figure 5] FIG. 2 is a functional block diagram illustrating the processing functions of a positioning reliability calculation unit together with related configurations including some functions of the GNSS receiver. [Figure 6] FIG. 2 is a functional block diagram illustrating the processing functions of a self-position reliability calculation unit together with related configurations including some functions of the GNSS receiver. [Figure 7] FIG. 2 is a functional block diagram showing the processing function of a construction information recording unit. [Figure 8] 10 is a flowchart showing the processing content of a representative position coordinate acquisition unit. [Figure 9] 10 is a flowchart showing the processing contents of a structure and topography data acquisition unit. [Figure 10] 10 is a flowchart showing the processing contents of a visible satellite identifying unit, a positioning accuracy calculating unit, and a positioning reliability map generating unit. [Figure 11] 10 is a flowchart showing the processing contents of a self-location reliability calculation unit. [Figure 12] 10 is a flowchart showing the processing contents of a construction information recording unit. [Figure 13] FIG. 10 is a diagram showing an example of a display of a positioning reliability map on a display device. [Figure 14] FIG. 10 is a diagram showing an example of a display of an estimated vertical error on a display device. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of the present invention will be described below with reference to the drawings. In this embodiment, a hydraulic excavator equipped with a front working implement will be described as an example of a work machine, but the present invention is not limited to this and can also be applied to other work machines that perform work using positioning results such as GNSS.

[0011] Fig. 1 is a diagram schematically showing the appearance of a hydraulic excavator 1, which is an example of a work machine according to this embodiment. Fig. 2 is a functional block diagram showing the relevant configuration of a machine guidance system 200 extracted from the control system that controls the overall operation of the hydraulic excavator 1.

[0012] In FIG. 1, the hydraulic excavator 1 comprises a multi-joint front working machine (working device) 5 formed by connecting a plurality of driven members (a boom 6, an arm 7, and a bucket 8) that each rotate vertically, and an upper rotating body 3 and a lower traveling body 2 that form the vehicle body, with the upper rotating body 3 being rotatable relative to the lower traveling body 2.

[0013] The base end of a boom 6 of the front working implement 5 is supported at the front of the upper rotating body 3 so as to be rotatable in the vertical direction, one end of an arm 7 is supported at an end (tip) different from the base end of the boom 6 so as to be rotatable in the vertical direction, and a bucket 8 is supported at the other end of the arm 7 so as to be rotatable in the vertical direction. The boom 6, arm 7, bucket 8, upper rotating body 3, and lower traveling body 2 are driven by hydraulic actuators: a boom cylinder 9, an arm cylinder 10, a bucket cylinder 11, a swing motor (not shown), and left and right traveling motors (not shown), respectively.

[0014] Inertial Measurement Units (IMUs) 21 to 24 are respectively disposed on the vehicle body (specifically, the upper rotating body 3), the boom 6, the arm 7, and the bucket 8. Hereinafter, when it is necessary to distinguish between these inertial measurement units 21 to 24, they will be referred to as the vehicle body inertial measurement unit 21, the boom inertial measurement unit 22, the arm inertial measurement unit 23, and the bucket inertial measurement unit 24, respectively.

[0015] The inertial measurement units 21-24 measure angular velocity and acceleration. When the upper rotating body 3 and the driven members 6-8 on which the inertial measurement units 21-24 are arranged are stationary, the orientations (ground angles) of the upper rotating body 3 and the driven members 6-8 can be detected as attitude information based on the direction of gravitational acceleration in the IMU coordinate system set in the inertial measurement units 21-24 (i.e., the vertical downward direction) and the mounting state of the inertial measurement units 21-24 (i.e., the relative positional relationship between the inertial measurement units 21-24 and the upper rotating body 3 and the driven members 6-8).

[0016] The detection results of the inertial measurement unit 21 can be used to calculate the tilt angle in the forward / backward direction (pitch angle) and the tilt angle in the left / right direction (roll angle) of the upper rotating body 3. Furthermore, the detection results of the inertial measurement units 21-24 can be used to calculate the relative angles of the upper rotating body 3 and the driven members 6-8, i.e., the rotation angle of the boom 6 relative to the upper rotating body 3 (boom angle), the rotation angle of the arm 7 relative to the boom 6 (arm angle), and the rotation angle of the bucket 8 relative to the arm 7 (bucket angle). Furthermore, the rotation angle of the upper rotating body 3 can be detected based on the angular velocity detected by the inertial measurement unit 21. In other words, the inertial measurement units 21-24 can also be considered angle detectors that detect the relative angles of the upper rotating body 3 and the driven members 6-8. An angle detection device may be used instead of the inertial measurement units 21-24 at the rotating portion of the upper rotating body 3 or the joints of the driven members 6-8. Here, the inertial measurement units 21 to 24 constitute a posture information measuring device that measures and outputs posture information, which is information relating to the posture of the hydraulic excavator 1.

[0017] An operator's cab 4, in which an operator sits, is located at the top front of the upper rotating body 3. The operator's cab 4 is provided with a plurality of operation levers (not shown) that output operation signals for operating a plurality of hydraulic actuators (boom cylinder 9, arm cylinder 10, bucket cylinder 11, swing motor, and travel motor), and each is assigned to operate a plurality of hydraulic actuators.

[0018] A display device 36 having a function of notifying an operator of information and a function of allowing the operator to input information is also disposed in the operator's cab 4. The screen of the display device 36 is provided with, for example, a touch panel formed on the surface, and the touch panel function can receive input from the operator.

[0019] Two GNSS antennas 31 and 32 for positioning using the Global Navigation Satellite System (GNSS) are arranged on the upper part of the upper rotating body 3, for example, behind the operator's cab 4. The GNSS antennas 31 and 32 receive navigation signals output from positioning satellites flying in the sky and send them to a GNSS receiver 33 (see FIG. 2). The GNSS receiver 33 calculates the positions of the GNSS antennas 31 and 32 in the Earth coordinate system based on the navigation signals received by the GNSS antennas 31 and 32, and outputs the calculated position information. Note that the site coordinate system set at the construction site can be easily converted to the Earth coordinate system, and a position in the Earth coordinate system can be said to be synonymous with a position in the site coordinate system.

[0020] Because the relative positions of the GNSS antennas 31, 32 with respect to the upper rotating body 3 are fixed and known, the position of the hydraulic excavator 1 in the Earth coordinate system can be calculated from the position information measured by the GNSS antennas 31, 32. Furthermore, from the deviation of the position information measured by the two GNSS antennas 31, 32, a direction vector between the GNSS antennas 31, 32 can be calculated, and the orientation of the upper rotating body 131 can be calculated.

[0021] Here, the GNSS receiver 33 including the GNSS antennas 31, 32 constitutes a position measurement device that measures the position of the hydraulic excavator 1, which is a work machine, at a construction site and outputs the measurement results as position information.

[0022] Further, for example, a radio set 34 is disposed on the upper rear side of the cab 4 for receiving correction data used for RTK (Real Time Kinematic) positioning (hereinafter referred to as RTK correction data) from a reference station.

[0023] FIG. 3 is a diagram showing an example of an external system 38 that functions as a reference station.

[0024] As shown in Figure 3, the external system 38 has a GNSS antenna 39 for positioning using GNSS, a GNSS receiver 40 that calculates the position of the GNSS antenna 39 in the Earth coordinate system based on the navigation signal received by the GNSS antenna 39 and generates RTK correction data based on the position of the GNSS antenna 39 shown in the calculation result and the position of the GNSS antenna 39 that has been measured separately in advance with high accuracy, and a radio 41 that outputs the RTK correction data generated by the GNSS receiver 40 via a radio antenna 41a.

[0025] 2, the machine guidance system 200 is composed of a GNSS receiver 33, a radio 34, a controller 35, a display device 36, inertial measurement units 21 to 24, and their associated components. An external storage medium (storage device) 37 is connected to the controller 35. The external storage medium (storage device) 37 stores three-dimensional design data that is the target shape of the construction site, three-dimensional topographical data of the surrounding area including the construction site, and three-dimensional structure data that indicates the positions and shapes of structures other than the topography included in the range of the three-dimensional topographical data.

[0026] The machine guidance system 200 includes a controller 35 that calculates the position and attitude of the hydraulic excavator 1, the position of the tip of the working implement (bucket 8), and the like, based on RTK correction data received from a reference station by a radio antenna 34a of a radio 34, position and orientation information calculated by a GNSS receiver 33 based on navigation signals received from positioning satellites by GNSS antennas 31 and 32, attitude information from the inertial measurement units 21 to 24, and information stored in an external storage medium 37. The controller 35 calculates, for example, the distance between the work target surface and the bucket 8, and outputs the calculation result to a display device 36 for display.

[0027] Although not shown, the controller 35 is hardware equivalent to a computer having a CPU (Central Processing Unit) as a processing device, and a storage device (for example, semiconductor memory such as ROM or RAM, or a hard disk drive) in which programs executed by the processing device and data necessary for executing the programs are stored. Note that if the controller 35 is configured using integrated circuits such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array), some or all of the functions of the controller 35 may be realized by these integrated circuits.

[0028] The controller 35 includes a machine guidance unit 35a that calculates the positional relationship between the position and attitude of the hydraulic excavator 1 and the three-dimensional design data and provides work support to the operator, a positioning reliability calculation unit 35b that calculates the reliability of GNSS positioning for the entire construction site, a self-position reliability calculation unit 35c that calculates the reliability of GNSS positioning at the position of the hydraulic excavator 1, and a construction information recording unit 35d that records the position coordinate data of the tip of the bucket 8 of the hydraulic excavator 1 and the reliability data of the GNSS positioning in association with each other.

[0029] FIG. 4 is a functional block diagram illustrating the processing functions of the machine guidance unit 35a together with the related configuration including some functions of the GNSS receiver 33.

[0030] In Figure 4, the GNSS receiver 33 has an RTK correction data receiving unit 100 that receives RTK correction data via the radio 34, a satellite signal receiving unit 101 that receives navigation signals via the GNSS antennas 31 and 32, a satellite selecting unit 102 that selects a positioning satellite to use for position calculation based on the satellite signal strength and satellite position, etc., and a GNSS position / vector calculation unit 103 that calculates the position of the GNSS antenna 31 and the vector from the GNSS antenna 31 to the GNSS antenna 32.

[0031] 4, the machine guidance unit 35a includes a vehicle body attitude calculation unit 104 that calculates the attitude of the vehicle body based on attitude information from the inertial measurement unit 21 provided on the vehicle body, a front attitude calculation unit 105 that calculates the attitude of the front work implement 5 based on attitude information from the inertial measurement units 22 to 24 provided on the front work implement 5, a three-dimensional design data acquisition unit 106 that acquires three-dimensional design data (target shape of the construction site) 37a stored in an external storage medium 37, a vehicle body position and attitude calculation unit 107 that calculates the position and attitude of the vehicle body in the site coordinate system based on the calculation results from the GNSS receiver 33 and the calculation results from the vehicle body attitude calculation unit 104, and a front attitude calculation unit 105 that calculates the attitude of the front work implement 5 based on attitude information from the inertial measurement units 22 to 24 provided on the front work implement 5. a cross section calculation unit 109 that calculates a cross section of the three-dimensional design data 37a in a work plane that is set to include the front work implement 5, based on the information from the position and attitude integration unit 108 and the information from the three-dimensional design data acquisition unit 106; and a distance calculation unit 110 that calculates the distance between the work target plane obtained from the three-dimensional design data and the front work implement 5 (specifically, the distance between the work target plane and the tip of the bucket 8) based on the information from the position and attitude integration unit 108 and the calculation result from the cross section calculation unit 109, and displays the distance on the display device 36.

[0032] The machine guidance unit 35a requires highly accurate position information, and therefore uses position information calculated by performing RTK positioning with the GNSS receiver 33. The RTK correction data receiving unit 100 receives, via the radio 34, RTK correction data that is generated in a reference station (external system) 38 and transmitted at regular intervals.

[0033] The GNSS receiver 33 performs RTK positioning of the three-dimensional position of the antenna 31 and the vector from the antenna 31 to the antenna 32 based on the RTK correction data received via the radio 34 and the signals from the positioning satellites received by the GNSS antennas 31 and 32. This RTK positioning allows the three-dimensional position of the antenna 31 and the vector from the antenna 31 to the antenna 32 to be measured with high accuracy.

[0034] Based on the various input data, controller 35 performs general vector calculations and coordinate conversions to calculate the position and attitude of hydraulic excavator 1 and the three-dimensional position of the tip of bucket 8. Furthermore, based on the position and attitude of hydraulic excavator 1 and three-dimensional design data 37a input from external storage medium 37, controller 35 calculates the cross-sectional shape of three-dimensional design data 37a and the distance between the tip of bucket 8 and the target surface.

[0035] By outputting the calculation results by the controller 35 to the display device 36, the operator can refer to the positional relationship between the hydraulic excavator 1 measured with high precision and the three-dimensional design data, thereby enabling soil shaping work to be performed with high quality.

[0036] FIG. 5 is a functional block diagram illustrating the processing functions of the positioning reliability calculation unit 35b together with the related configuration including some functions of the GNSS receiver 33.

[0037] 5, the GNSS receiver 33 has a satellite orbit information receiving unit 111 that receives satellite orbit information of each positioning satellite via a radio 34. The satellite orbit information receiving unit 111 receives, via the radio 34, satellite orbit information that is stored in a GNSS receiver 40 of a reference station (external system 38) and transmitted via a radio 41, for example.

[0038] 5, the positioning reliability calculation unit 35b includes a structure and topography data acquisition unit 112 that acquires structure position and shape data (i.e., three-dimensional topography data, three-dimensional structure data) 37b stored in the external storage medium 37 and integrates it with current topography data 300 that represents the current topography of the construction site that is sequentially stored, a three-dimensional design data acquisition unit 106 (a functional unit shared with the machine guidance unit 35a, etc.) that acquires three-dimensional design data (target shape of the construction site) 37a stored in the external storage medium 37, and a three-dimensional design data acquisition unit 106 that divides the construction site into a plurality of regions (blocks) of a predetermined size based on the coordinate range of the three-dimensional design data 37a acquired by the three-dimensional design data acquisition unit 106, and calculates the coordinates of the divided plurality of regions (blocks). The system includes a representative position coordinate acquisition unit 113 that acquires a representative position (e.g., a center of gravity position) for each of the regions; a visible satellite identification unit 114 that identifies visible satellites (i.e., positioning satellites that can receive navigation signals at the representative positions) at any time at the representative positions of each of the multiple regions acquired by the representative position coordinate acquisition unit 113 based on the structure position / shape data 37b and satellite orbit information; a positioning accuracy calculation unit 115 that calculates information related to the positioning accuracy by the GNSS receiver 33 (e.g., position dilution of precision (PDOP), which is one of the accuracy indicators) for the visible satellites identified by the visible satellite identification unit 114 based on the structure position / shape data 37b and the satellite orbit information obtained via the visible satellite identification unit 114) for each of the representative positions of the multiple regions; and a positioning reliability map generation unit 116 that generates a positioning reliability map that links the information related to the positioning accuracy (e.g., position dilution of precision (PDOP)) with the representative positions of each of the multiple regions, and outputs the map to the display device 36 for display.

[0039] 8 to 10 are flowcharts showing the processing contents of the positioning reliability calculation unit 35b, FIG. 8 is a flowchart showing the processing contents of the representative position coordinate acquisition unit, FIG. 9 is a flowchart showing the processing contents of the structure and topography data acquisition unit 112, and FIG. 10 is a flowchart showing the processing contents of the visible satellite identification unit, the positioning accuracy calculation unit, and the positioning reliability map generation unit.

[0040] The positioning reliability calculation unit 35b acquires in advance via the GNSS receiver 33 the satellite locations at representative positions in each area in order to calculate the reliability of GNSS positioning for the entire construction site, which is the working area of ​​the hydraulic excavator 1.

[0041] As shown in FIG. 8, the positioning reliability calculation unit 35b first acquires the three-dimensional design data 37a (step S100), divides the planar coordinates (=work area) of the three-dimensional design data 37a into regions of a predetermined size, and acquires the coordinates of the representative position of each region (step S110).

[0042] As shown in FIG. 9, the positioning reliability calculation unit 35b acquires structure position and shape data (i.e., three-dimensional topography data, three-dimensional structure data) 37b (step S200). To identify visible satellites at each representative position, information on obstacles that block the positioning satellite signals is required. At a construction site, the obstacles are structures around the site and the topography of the site. The data on these obstacles are acquired in different ways, and since the structures around the site do not change significantly from day to day, the controller 35 can acquire this information by storing structure position and shape data 37b indicating the position and shape data of the structures in the external storage medium 37.

[0043] Also, the controller 35 reads and acquires the current terrain data 300 stored in a storage area (not shown) (step S210). Since the terrain of the work site changes from moment to moment depending on the work being done, the position data of the tip of the bucket 8 of the hydraulic excavator 1 is stored in the controller 35 as the current terrain data 300.

[0044] Next, the structure position and shape data 37b is integrated with the current topography data 300 (step S220). By integrating the information in this way, it is possible to obtain information on the shape and position of obstacles that may block navigation signals from the positioning satellite at each representative position within the construction site.

[0045] 10, the positioning reliability calculation unit 35b acquires satellite orbit information (step S300). To acquire the satellite constellation at each work position, satellite orbit information for all positioning satellites is acquired from the external system 38 via the radio 34 of the GNSS receiver 33. Here, the satellite orbit information is information indicating the flight start of each positioning satellite and its position at each time in the past and future, and is information that has been identified and made public in advance by an administrator of the positioning satellite, etc. Note that because each positioning satellite orbits the Earth at a regular interval, it is also possible to acquire satellite orbit information (time-series data of the satellite constellation) for several hours in the future in advance.

[0046] Next, visible satellites at each representative position are identified from the positioning satellite arrangement information, the coordinates of each representative position, and the shape data of obstacles (step S310).

[0047] In this embodiment, if there is no obstacle between the line connecting each representative position of a plurality of areas and the position of a positioning satellite, the positioning satellite is determined to be a visible satellite. For example, if the position of a certain positioning satellite is Pi, the operation position is pi, the normal of a certain face constituting the shape of an obstacle is n, and the vertices are a, b, and c, it can be determined whether or not the positioning satellite is a visible satellite by performing intersection determination using the following (Equation 1) to (Equation 3).

[0048]

number

[0049]

number

[0050]

number

[0051] Here, R(t) is the coordinate of the intersection point where a surface constituting the shape of the obstacle intersects with the line from satellite Pi to work position pi, and t represents the distance from satellite Pi to intersection point R(t). Also, u and v are variables used to determine whether intersection point R(t) exists inside the surface.

[0052] Next, the position dilution of precision (PDOP) of each representative position is calculated using the position information of visible satellites (step S320).

[0053] The position dilution of precision (PDOP) is widely used as an index of GNSS positioning accuracy caused by satellite placement, and can be calculated using the following formula (4):

[0054]

number

[0055] Here, σxx^2, σyy^2, and σzz^2 in the above (Equation 4) can be calculated by the following (Equation 5) and (Equation 6).

[0056]

number

[0057]

number

[0058] The above (Equation 5) and (Equation 6) use the trace of the covariance matrix G, which is determined from the geometric relationship between the satellite position and the work position. Note that EL and AZ in the above (Equation 6) are the elevation angle and azimuth angle, respectively, that represent the satellite position.

[0059] Next, the obtained Dilution of Precision (PDOP) of each representative position is associated with each of the multiple regions to generate a positioning reliability map (step S330). Note that by using time-series data of satellite constellation (satellite orbit information), the PDOP can be calculated using a similar procedure to calculate not only the current value but also the value several hours from now. In other words, a positioning reliability map for any date and time can be generated.

[0060] FIG. 13 is a diagram showing an example of a display of a positioning reliability map on the display device 36. As shown in FIG.

[0061] 13, on the display device 36, a shovel icon 124 indicating the position and orientation of the hydraulic excavator 1 at the construction site is superimposed on an overhead view 123 of three-dimensional design data 37a at the construction site. The shovel icon 124 is drawn based on the position and orientation of the hydraulic excavator 1 output from the machine guidance unit 35a, for example, so that the positional relationship between the overhead view 123 of the three-dimensional design data 37a and the shovel icon 124 is displayed correctly. Furthermore, a reliability map 125 is superimposed on the overhead view 123 of the three-dimensional design data 37a, and the positional dilution rate of precision (PDOP) of the representative position of each region (block) is drawn using, for example, color information corresponding to the positional dilution rate. In this embodiment, the positional dilution rate is illustrated by hatching or the like. In addition, a time adjustment bar 126 is displayed, and by operating 126a of the time adjustment bar 126, the operator can switch the display to a positioning reliability map that reflects the position dilution of precision (PDOP) at a certain point in time several hours from now (any time).

[0062] As described above, the operator can know the reliability of satellite positioning at each location for the entire construction site, both now and several hours from now (any time), allowing them to consider the optimal setup (route to work locations) and improve work efficiency.

[0063] FIG. 6 is a functional block diagram illustrating the processing functions of the self-position reliability calculation unit 35c together with the related configuration including some functions of the GNSS receiver 33.

[0064] 6, the GNSS receiver 33 has a position variance calculation unit 117 that calculates the position variance of the antenna 31 (position variance data).

[0065] 6, the self-position reliability calculation unit 35c includes a position variance acquisition unit 118 that acquires position variance data from the GNSS receiver 33, a three-dimensional design data acquisition unit 106 that acquires three-dimensional design data (target shape of the construction site) 37a stored in the external storage medium 37, a vehicle body position and attitude calculation unit 107 that calculates the position and attitude of the vehicle body in the site coordinate system based on the calculation results from the GNSS receiver 33 and the calculation results from the vehicle body attitude calculation unit 104, a position and attitude integration unit 108 that integrates the calculation results from the vehicle body position and attitude calculation unit 107 and the calculation results from the front attitude calculation unit 105 to output the position and attitude of the entire hydraulic excavator 1 including the front work implement 5 in the site coordinate system, and a three-dimensional design data acquisition unit 106 that acquires three-dimensional design data (target shape of the construction site) 37a stored in the external storage medium 37. The machine guidance unit 35a includes a target surface acquisition unit 119 that acquires a target surface to be worked on by the hydraulic excavator 1 from among the many surfaces constituting the three-dimensional design data 37a, based on the acquired three-dimensional design data 37a and the information on the position and attitude of the hydraulic excavator 1 integrated by the position and attitude integration unit 108, and an estimated vertical error calculation unit 120 that calculates an estimated vertical error, which is the error in the position of the working implement (bucket 8) in the vertical direction (height direction) relative to the target surface (error in the distance between the target surface and the bucket), based on the position variance data acquired by the position variance acquisition unit 118, the target surface acquired by the target surface acquisition unit 119, and the position and attitude of the vehicle body calculated by the vehicle body position and attitude calculation unit 107 (i.e., the direction vector of the hydraulic excavator 1 calculated by the machine guidance unit 35a). The three-dimensional design data acquisition unit 106, the vehicle body position and attitude calculation unit 107, and the position and attitude integration unit 108 are functional units shared with the machine guidance unit 35a, etc.

[0066] FIG. 11 is a flowchart showing the processing contents of the self-location reliability calculation unit 35c.

[0067] The self-position reliability calculation unit 35c is a functional unit that calculates the influence of the accuracy of GNSS positioning on the excavation accuracy of the target surface of the hydraulic excavator 1 as an error in the vertical direction, which is the excavation direction.

[0068] 11, the self-position reliability calculation unit 35c first acquires the three-dimensional design data 37a (step S400), acquires the tip position of the bucket 8 (step S410), and then, from this information, identifies a target surface that is the current work target of the hydraulic excavator 1 from the three-dimensional design data 37a made up of multiple surfaces, and acquires data on the target surface (step S420). Note that, although the present embodiment illustrates a case where the system automatically identifies the target surface, it may also be configured so that the operator manually selects it.

[0069] When performing excavation work, the tip of the bucket 8 of the hydraulic excavator 1 is located on the target surface, so the target surface that is the current work target can be identified by determining whether a line drawn vertically from the position of the tip of the bucket 8 intersects with a surface that constitutes the three-dimensional design data 37a. Identification of the target surface can be achieved by substituting the above (Equations 1) to (Equations 3), in the same way as the intersection determination between the satellite signal and an obstacle. Note that, for an adjacent surface adjacent to the identified target surface, if the normal vector of the target surface matches the normal vector of the adjacent surface, the adjacent surface is treated as part of the target surface.

[0070] Next, the direction vector of the hydraulic excavator 1, the target surface of the work object, and the position dispersion data of the antenna 31 calculated by the GNSS receiver 33 are acquired (step S430), and an estimated vertical error representing the reliability of satellite positioning at the current position of the hydraulic excavator 1 is calculated (step S440).

[0071] The estimated vertical error is calculated using the following (Equation 7) and (Equation 8).

[0072]

number

[0073]

number

[0074] First, the horizontal error Eh is calculated using the horizontal variances σxx and σyy using Equation 7 above. The error Eh is set to 2DRMS, which is a commonly used index. Next, the estimated vertical error Ed in the distance between the bucket 8 and the target surface is calculated using the vertical variance σzz and the horizontal error Eh calculated using Equation 7 above using Equation 8 above. The gradient θm of the target surface is the ground angle between the intersection of the plane passing through the front work implement 5 (boom 6, arm 7, bucket 8) and the target surface.

[0075] In the above (Equation 7) and (Equation 8), the distance between the bucket 8 and the target surface is calculated using the horizontal position variance and the vertical position variance, but the GNSS receiver 33 also calculates the azimuth angle and azimuth angle variance from the vector (baseline vector) between the antennas. Therefore, when determining the estimated vertical error Ed of the vertical distance between the bucket 8 and the target surface, the error in the horizontal position of the bucket 8 may be calculated using the azimuth angle variance in addition to the horizontal position variance.

[0076] FIG. 14 is a diagram showing an example of the display of the estimated vertical error on the display device 36.

[0077] As shown in FIG. 14, the display device 36 displays numerical information 127 output by the machine guidance unit 35a indicating the distance from the tip of the bucket 8 to the target surface, and a light bar 128 indicating the distance by display area and color.

[0078] The estimated vertical error 129 output from the self-position reliability calculation unit 35c is displayed together with the numerical information 127 representing the distance. Although not shown, the color information of the light bar 128 may be changed depending on the magnitude of the estimated vertical error.

[0079] With the above configuration, the operator can determine how much to trust the information about the distance from the tip of the bucket 8 to the target surface. Furthermore, if the estimated vertical error is a value that exceeds the accuracy required at the construction site, the operator can check the reliability map output by the positioning reliability calculation unit 35b and reconsider the construction arrangements.

[0080] FIG. 7 is a functional block diagram showing the processing functions of the construction information recording unit 35d.

[0081] 7, the construction information recording unit 35d includes a position and attitude integration unit 108 that integrates the calculation results from the vehicle body position and attitude calculation unit 107 and the front attitude calculation unit 105, and outputs the position and attitude of the entire hydraulic excavator 1 including the front work implement 5 in the site coordinate system; an estimated vertical error calculation unit 120 that calculates an estimated vertical error of the implement (bucket 8) with respect to the target plane, based on the position variance data acquired by the position variance acquisition unit 118, the target plane acquired by the target plane acquisition unit 119, and the vehicle body position and attitude calculated by the vehicle body position and attitude calculation unit 107 (i.e., the direction vector of the hydraulic excavator 1 calculated by the machine guidance unit 35a); and an estimated vertical error calculation unit 120 that calculates information related to the positioning accuracy of the GNSS receiver 33 (for example, position dilution of precision (PDOP) which is one of the accuracy indicators) for the visible satellites identified by the visible satellite identification unit 114, based on the structure position and shape data 37b obtained via the visible satellite identification unit 114 and satellite orbit information. The position and attitude integration unit 108 includes a positioning accuracy calculation unit 115 that calculates the positioning accuracy (Positioning Accuracy) for each of the representative positions of a plurality of regions, a current terrain data update determination unit 121 that determines whether to update current terrain data 300 that represents the current shape of the earth and sand at the construction site based on the current position coordinates of the tip of the bucket 8 of the hydraulic excavator 1, and a current terrain and positioning reliability recording unit 122 that also records the reliability of GNSS positioning when updating the current terrain data 300. Note that the position and attitude integration unit 108, the positioning accuracy calculation unit 115, and the current terrain data 300 are functional units that are shared with the machine guidance unit 35a, the positioning reliability calculation unit 35b, the self-position reliability calculation unit 35c, etc.

[0082] FIG. 12 is a flowchart showing the processing contents of the construction information recording unit 35d.

[0083] The construction information recording unit 35d is a functional unit that measures three-dimensional position data representing the shape of the current terrain that has changed due to the excavation work of the hydraulic excavator 1 using the position coordinates of the tip of the bucket 8, and records the position coordinates of the tip of the bucket 8 in association with the positional dilution of precision (PDOP) calculated by the positioning reliability calculation unit 35b and the estimated vertical error output by the self-position reliability calculation unit 35c.

[0084] As shown in FIG. 12, first, the construction information recording unit 35d acquires the position coordinate data (referred to as current position coordinates) of the tip of the bucket 8 calculated by the machine guidance unit 35a (step S500).

[0085] Next, the current terrain data (referred to as past position coordinates) in the X and Y coordinates of the current position coordinates is acquired (step S510), and the Z coordinate value of the current position coordinates is compared with the Z coordinate value of the past position coordinates to determine whether or not to update the current terrain data 300 (step S520). In step S520, if the Z component of the current position coordinates is smaller than the Z component of the past position coordinates, it is determined that the current terrain data 300 should be updated to the current position coordinates (YES). On the other hand, if the Z component of the current position coordinates is larger than the Z component of the past position coordinates, it is determined that the current terrain data 300 should not be updated to the current position coordinates (NO).

[0086] If the determination result in step S520 is YES, that is, if it is determined that the current terrain data should be updated, the position dilution of precision (PDOP) and estimated vertical error (i.e., positioning reliability) are obtained (step S530), and the current position coordinates and the position dilution of precision (PDOP) and estimated vertical error (i.e., positioning reliability) at that time are linked to the current terrain data and recorded as current terrain data 300 in a memory area (not shown) of the controller 35 (step S540).

[0087] With the above configuration, the construction history information recorded in the controller 35 is output to the external storage medium 37, and the operator and construction manager can utilize the construction history information as operation data for the hydraulic excavator 1. In other words, since they can refer to the current topography shaped by the hydraulic excavator 1 and the reliability of that shape, they can determine whether or not to use the current topography data 300 for as-built management, etc.

[0088] The effects of the present embodiment configured as above will be described.

[0089] In information-based construction, the accuracy of construction work by hydraulic excavators and other work machines is greatly affected by positioning accuracy. For this reason, users of work machines must take the positioning accuracy of the work machine into consideration when planning work. However, because the positioning accuracy of GNSS varies depending on the positions of the work machine and positioning satellites at the work site, as well as the work site environment, it is not easy to plan work appropriately. Furthermore, if work planning cannot be done appropriately, there is a concern that the efficiency of the entire construction work will decrease.

[0090] In contrast to this, in this embodiment, the system includes a lower traveling body, an upper rotating body that is rotatably provided on the lower traveling body and that constitutes a vehicle body together with the lower traveling body, a working device that is configured by rotatably connecting a plurality of driven members including a working implement to each other and is rotatably supported on the upper rotating body, an attitude information measuring device that measures attitude information of each of the upper rotating body and the plurality of driven members, a position measuring device that calculates the position and orientation of the vehicle body at the construction site based on navigation signals from positioning satellites, a storage device that stores design data that is the target shape of the construction site, topographical data of the surrounding area including the construction site, and structure data that indicates the positions and shapes of structures included in the range of the topographical data, and calculation results from the position measuring device and information from the attitude information measuring device. In a construction machine equipped with a controller that calculates the distance between the work target surface obtained from the design data and the work implement attached to the tip of the work device based on attitude information from the GNSS, the controller divides the construction site into multiple areas based on the design data, sets a representative position for each of the multiple divided areas, calculates the positioning accuracy of the position measurement device for each representative position of the multiple areas based on the orbital information of the positioning satellites, topographical data, and structure data, and generates a positioning reliability map that links the positioning accuracy with the representative position of each of the multiple areas.Therefore, by appropriately providing information related to the GNSS positioning accuracy to the user of the construction machine, it is possible to support work arrangements and improve the efficiency of the entire construction work.

[0091] That is, the reliability of GNSS positioning can be obtained for the entire construction site and the current machine position in combination with the work support information calculated by the machine guidance unit 35a. As a result, the operator can decide whether to continue the current work and consider moving to another work position, improving the efficiency of setup and ultimately the efficiency of the entire work.

[0092] <Additional Notes> The present invention is not limited to the above-described embodiments, and includes various modifications and combinations within the scope of the gist thereof. Furthermore, the present invention is not limited to those including all of the configurations described in the above-described embodiments, and includes those in which some of the configurations are omitted. Furthermore, the above-described configurations, functions, etc. may be realized in part or in whole by designing them as, for example, integrated circuits. Furthermore, the above-described configurations, functions, etc. may be realized in software by a processor interpreting and executing a program that realizes each function. [Explanation of symbols]

[0093] 1...hydraulic excavator, 2...lower running body, 3...upper rotating body, 4...operator cab, 5...front work machine (working device), 6...boom, 7...arm, 8...bucket, 9...boom cylinder, 10...arm cylinder, 11...bucket cylinder, 21-24...inertial measurement unit (IMU), 31, 32...GNSS antenna, 34...radio, 34a...radio antenna, 35...controller, 35a...machine guidance unit, 35b...positioning reliability calculation unit, 35c...self-position reliability calculation unit, 35d...construction information recording unit, 36...display device, 37...external storage medium (storage device), 37a...three-dimensional design data, 37b...structure position and shape data, 38...reference station (external system), 39...GNSS antenna, 40...GNSS receiver, 41...radio, 41a...radio antenna, 100...RTK correction data receiving unit, 101...satellite signal receiving unit, 102...satellite selection unit, 103...GNSS position and shape data vector calculation unit, 104... vehicle body attitude calculation unit, 105... front attitude calculation unit, 106... three-dimensional design data acquisition unit, 107... vehicle body position and attitude calculation unit, 108... position and attitude integration unit, 109... cross-section calculation unit, 110... distance calculation unit, 111... satellite orbit information receiving unit, 112... structure and terrain data acquisition unit, 113... representative position coordinate acquisition unit, 114... visible satellite identification unit, 115... positioning accuracy calculation unit, 116... positioning reliability map generation unit, 117... position distribution dispersion calculation unit, 118...position dispersion acquisition unit, 119...target surface acquisition unit, 120...estimated vertical error calculation unit, 121...current terrain data update determination unit, 122...current terrain and positioning reliability recording unit, 123...bird's-eye view, 124...shovel icon, 125...reliability map, 126...time adjustment bar, 127...numerical information, 128...light bar, 129...estimated vertical error, 131...upper rotating body, 200...machine guidance system, 300...current terrain data

Claims

1. a lower running body; an upper rotating body that is rotatably provided on the lower traveling body and that constitutes a vehicle body together with the lower traveling body; a working device configured by a plurality of driven members including working implements rotatably connected to one another and rotatably supported on the upper rotating body; a posture information measuring device that measures posture information of the upper rotating body and the plurality of driven members; a position measurement device that calculates the position and orientation of the vehicle body at the construction site based on a navigation signal from a positioning satellite; a controller that calculates a distance between a work target surface obtained from design data that is a target shape of the construction site and a work implement attached to a tip of the work implement based on a calculation result from the position measurement device and posture information from the posture information measurement device, The controller Dividing the construction site into a plurality of areas based on the design data; A representative position is set for each of the divided regions; Calculating the positioning accuracy of the position measuring device for each representative position of the plurality of areas based on the orbital information of the positioning satellite, topographical data of the surrounding area including the construction site, and structure data indicating the position and shape of structures included in the range of the topographical data; generating a positioning reliability map that associates the positioning accuracy with each of the representative positions of the plurality of regions; determining whether or not to record coordinates of the work tool based on a distance between the work tool disposed at the tip of the work device and the work target surface; When it is determined that the coordinates of the work implement should be recorded, the coordinates of the work implement are associated with the positioning accuracy and stored in a storage device.

2. a lower running body; an upper rotating body that is rotatably provided on the lower traveling body and that constitutes a vehicle body together with the lower traveling body; a working device configured by a plurality of driven members including working implements rotatably connected to one another and rotatably supported on the upper rotating body; a posture information measuring device that measures posture information of the upper rotating body and the plurality of driven members; a position measurement device that calculates the position and orientation of the vehicle body at the construction site based on a navigation signal from a positioning satellite; a controller that calculates a distance between a work target surface obtained from design data that is a target shape of the construction site and a work implement attached to a tip of the work implement based on a calculation result from the position measurement device and posture information from the posture information measurement device, the position measurement device calculates a position variance, which is a variance of a calculation result of the position of the vehicle body at the construction site; The controller Dividing the construction site into a plurality of areas based on the design data; A representative position is set for each of the divided regions; Calculating the positioning accuracy of the position measuring device for each representative position of the plurality of areas based on the orbital information of the positioning satellite, topographical data of the surrounding area including the construction site, and structure data indicating the position and shape of structures included in the range of the topographical data; generating a positioning reliability map that indicates the positioning accuracy and each representative position of the plurality of regions in association with each other; Calculating an estimated vertical error, which is the accuracy of the position of the work tool in a vertical direction relative to the work target surface, based on the position variance; determining whether or not to record coordinates of the work tool based on a distance between the work tool disposed at the tip of the work device and the work target surface; When it is determined that the coordinates of the work implement should be recorded, the coordinates of the work implement and the estimated vertical error are linked and stored in a storage device.

3. 2. The work machine according to claim 1, The controller generates an overhead view image in which information on the three-dimensional position and orientation of the vehicle body is superimposed on the positioning reliability map, and displays the image on a display device.

4. 2. The work machine according to claim 1, the position measurement device calculates a position variance, which is a variance of a calculation result of the position of the vehicle body at the construction site; The working machine is characterized in that the controller calculates an estimated vertical error, which is the accuracy of the position of the working implement in a direction vertical to the work target surface, based on the position variance.

5. 5. The work machine according to claim 4, the controller generates a distance display image that simultaneously displays the distance between the work implement disposed at the tip of the work device and the work target surface, and the estimated vertical error, based on the estimated vertical error, and displays the image on a display device.

Images