JP7613922B2 - Positioning accuracy output system and server device thereof - Google Patents

Description

The present invention relates to a positioning accuracy output system and its server device.

Informatized construction, which applies information and communication technology to construction using hydraulic excavators and other construction machinery, is being promoted. In informationized construction, machine control (3D-MC) or machine guidance (MG) of construction machinery is performed so that construction is carried out according to 3D design data while 3D surveying of the construction target is carried out, and the progress and accuracy of construction are managed using position information of the construction machinery and the construction target (for example, Patent Document 1).

Patent Document 1 describes a work machine having a calculation unit that calculates the position coordinates of the vehicle body and the longitudinal direction of the work machine from the measurement results of the position measurement device and the orientation measurement device, an information generation unit that sets another design surface adjacent to the first target surface among multiple design surfaces that make up the three-dimensional design data as a second target surface and generates first operation support information including the amount of rotation of the upper rotating body to make the longitudinal direction of the work machine parallel to the boundary line between the first target surface and the second target surface when viewed from above the vehicle body, and an information output unit that outputs the first operation support information generated by the information generation unit to a display device.

JP 2019-157600 A

In information-based construction, a satellite positioning system is used to position and survey the construction machinery and construction target. In a satellite positioning system, the positioning accuracy may decrease due to the influence of the positioning satellite's position and multipath, as highly accurate position information cannot be calculated or the position information may jump up discontinuously. If the positioning accuracy decreases, the construction accuracy may decrease or machine control may become impossible, so the construction company at the construction site may stop construction work using the satellite positioning system. It is important to let the construction company understand the state of the positioning accuracy, but the work machine of Patent Document 1 does not take this into consideration at all, and depending on the state of the positioning accuracy, there is a possibility that the construction work may not be carried out as planned.

In view of the above circumstances, the present invention aims to provide a positioning accuracy output system and its server device that can easily present the positioning accuracy status of construction machinery that uses a satellite positioning system to construction workers and support planned and efficient construction work.

In order to solve the above problem, the positioning accuracy output system of the present invention is a positioning accuracy output system having a construction machine that performs positioning based on radio waves from a positioning satellite, and a server device that is communicatively connected to the construction machine and outputs the state of the positioning accuracy of the construction machine, the construction machine is equipped with a GNSS receiver that acquires satellite information including information about the position and orbit of the positioning satellite from the radio waves, performs positioning based on the satellite information, and acquires position information of the construction machine, and a controller that calculates the positioning accuracy based on the satellite information and acquires the positioning accuracy information, and the server device determines the state of the positioning accuracy at the position of the construction machine based on the position information, the positioning accuracy information, and the satellite information transmitted from the construction machine, and outputs a symbol according to the determination result.

According to the present invention, the positioning accuracy of construction machinery that uses a satellite positioning system can be presented to construction workers in an easy-to-understand manner, supporting planned and efficient construction work.

FIG. 1 is a diagram showing the configuration of a positioning accuracy output system according to an embodiment of the present invention. FIG. 2 is a diagram for explaining the RTK-GPS positioning method. FIG. 2 is a diagram showing a functional configuration of the positioning accuracy output system shown in FIG. 1 . 10 is a flowchart showing the flow of a process for determining the state of positioning accuracy. 5 is a flowchart showing a process flow relating to multipath prediction shown in FIG. 4 . FIG. 4 is a diagram showing a first example of a screen displayed on a display unit of the terminal device. FIG. 13 is a diagram showing a second example of a screen displayed on the display unit of the terminal device. FIG. 13 is a diagram showing a third example of a screen displayed on the display unit of the terminal device. FIG. 13 is a diagram showing a fourth example of a screen displayed on the display unit of the terminal device.

Embodiments of the present invention will be described below with reference to the drawings. Components with the same reference numerals in each embodiment have the same functions in each embodiment unless otherwise specified, and the description thereof will be omitted.

Figure 1 is a diagram showing the configuration of the positioning accuracy output system 1 of this embodiment.

The positioning accuracy output system 1 is a system that outputs the state of the positioning accuracy of a construction machine 10 that uses a satellite positioning system for positioning. The positioning accuracy output system 1 has a construction machine 10, a positioning satellite 20, a server device 30, and a terminal device 40.

The construction machine 10 is a construction machine such as a hydraulic excavator or a dump truck that can measure its own position based on radio waves from a positioning satellite 20. In FIG. 1, the construction machine 10 is shown as an example of a hydraulic excavator equipped with a lower traveling body 10a, an upper rotating body 10b, and a front working machine 10c.

The construction machine 10 is equipped with a GNSS (Global Navigation Satellite System) receiver 11 that receives radio waves from positioning satellites 20, a controller 12 that performs various processes according to various programs and performs overall control of each component of the construction machine 10, and a communication device 13 that communicates with a server device 30. In addition, the construction machine 10 is equipped with a monitor 14 that displays the processing results of the controller 12 and the operating status of the construction machine 10, and a camera 15 equipped with a wide-angle lens such as a hemispherical or spherical camera that captures images of the surroundings of the construction machine 10 and the sky above.

The positioning satellite 20 is an artificial satellite that constitutes a satellite positioning system such as Japan's Quasi-Zenith Satellite System (QZSS), the United States' GPS, the European Union's Galileo, China's BeiDou, or Russia's GLONASS. The server device 30 is a device such as a cloud server that is communicatively connected to the construction machine 10, manages the construction machine 10, and outputs information indicating the state of the positioning accuracy of the construction machine 10. The terminal device 40 is a device such as a tablet or PC that is communicatively connected to the server device 30 and presents information indicating the state of the positioning accuracy transmitted from the server device 30 to a construction company, etc. The terminal device 40 has a display unit 41 such as a touch panel display, and displays information indicating the state of the positioning accuracy transmitted from the server device 30 on the display unit 41.

Figure 2 is a diagram explaining the RTK-GPS positioning method.

Positioning methods using satellite positioning systems include the independent positioning method used for car and ship navigation, and the relative positioning method. The relative positioning method improves accuracy by correcting errors through relative positioning with a reference point. In the independent positioning method, the distance between the satellite and the GNSS receiver is calculated from the time when the four positioning satellites orbiting about 20,000 km above the ground emitted radio waves and the time when the radio waves were received by a GNSS receiver on the ground, and the position of the GNSS reception is calculated from the relative positions of the positioning satellites and the distance from the satellites. Here, four positioning satellites are required to determine a three-dimensional position, as time is one variable. In the independent positioning method, radio wave delays are a cause of errors.

On the other hand, in the relative positioning method, four or more positioning satellites are captured simultaneously by two or more GNSS receivers. In this case, the time difference when the radio waves from the positioning satellite reach each GNSS receiver is calculated based on the position of the positioning satellite, and the relative positional relationship of the two or more GNSS receivers is calculated. Since each GNSS receiver receives radio waves from the same positioning satellite, the weather conditions until the radio waves from the positioning satellite reach the ground are the same, and the position error of the positioning satellite and the delay of the radio waves due to the troposphere or ionosphere are eliminated. In addition, in the relative positioning method, the difference in the time it takes for the radio waves from the positioning satellite to reach each GNSS receiver is calculated from the difference in the phase of the radio waves. In this case, the phase (distance from the satellite) contains uncertainty (integer value bias) of the number of waves (an integer part of 2π), so complex calculations are required to remove this.

Relative positioning methods include D-GPS (Differential GPS), which uses multiple GNSS receivers to perform standalone positioning and determine relative positions from their respective position information, and RTK-GPS (Real-Time Kinematic GPS; interferometric positioning method), which determines the relative positions between multiple GNSS receivers from the distance between each GNSS receiver and a positioning satellite. D-GPS performs positioning using code information contained in radio waves. RTK-GPS performs positioning using phase data from radio waves. With D-GPS and RTK-GPS, radio waves from a positioning satellite are received simultaneously at a reference station whose position is known and at a measurement point whose position is to be determined, and the phase data measured at the reference station is transmitted in real time to the measurement point by wireless or other means, determining the position of the measurement point with high accuracy.

Specifically, D-GPS calculates the difference between the reference position at the reference station and the measured coordinate value, and transmits this to the measurement point as correction information. On the other hand, RTK-GPS calculates phase data of the radio waves received at the reference station (base) and measurement point (rover), and transmits the phase data calculated at the reference station to the measurement point.

Figure 2 is an explanatory diagram of RTK-GPS, showing an example in which four positioning satellites 20a to 20d fly above the construction machine 10, which is the measurement point, and a reference station 25 is installed around the construction machine 10. The GNSS receiver 11 of the construction machine 10 is also called a mobile station. The GNSS receiver 11 of the construction machine 10 and the GNSS receiver of the reference station 25 simultaneously receive radio waves from the positioning satellites 20a to 20d. The reference station 25 transmits the measured phase data to the GNSS receiver 11 of the construction machine 10. The GNSS receiver 11 analyzes the phase data of the received radio waves and the phase data transmitted from the reference station 25 in real time to determine the relative positional relationship from the reference station 25, and can determine the position of the measurement point with high accuracy.

The phase data of the radio wave is expressed as in equation (1).

In formula (1), Φ _iA is the carrier phase data from the positioning satellite i measured by the GNSS receiver A. f is the carrier frequency. c is the speed of light. r _iA is the true distance between the GNSS receiver A and the positioning satellite i. _{d i} is the error of the carrier phase data due to the clock error of the positioning satellite i. δ _A is the error of the carrier phase data due to the internal clock error of the GNSS receiver A. N _iA is an ambiguity (integer value). From formula (1), the true distance r _iA between the GNSS receiver A and the positioning satellite i is obtained. As a result, for example, the distance R1 from the positioning satellite 20a to the GNSS receiver 11 and the distance R2 from the positioning satellite 20a to the reference station 25 are obtained. Then, the distance L (baseline length) between the construction machine 10, which is the measurement point, and the reference station 25 is obtained from the difference between the distance R1 and the distance R2. This makes it possible to determine the position of the construction machine 10, which is the measurement point, with high accuracy.

In addition, RTK-GPS generally uses radio waves from six or more positioning satellites to determine the distance to the positioning satellite. Furthermore, there is a system of RTK-GPS called network-type RTK-GPS. In network-type RTK-GPS, errors contained in the measurement points are corrected using real-time survey data from electronic reference points. In D-GPS and RTK-GPS, various error factors are eliminated, so the position accuracy of D-GPS is about a few meters, and that of RTK-GPS is about a few centimeters.

Error factors in RTK-GPS include errors due to the position of the positioning satellite. The positioning error at the measurement point varies depending on the position of the positioning satellite. Ideally, the positions of the positioning satellites are distributed relatively between high and low altitudes. Radio waves from low-altitude positioning satellites are a source of error because the distance they travel through the atmosphere is long. Positioning satellites lower than the horizon are unable to be captured as they move, which also causes errors. Clock errors and GNSS receiver noise are also sources of error. Note that, unlike the point-based positioning method, the relative positioning method receives radio waves at multiple measurement points and aims to improve the positioning accuracy of the baseline length by offsetting the effects of error factors common to each measurement point.

Furthermore, one of the error factors in RTK-GPS is error due to the orbit of the positioning satellite. The position of the positioning satellite is determined using orbit information contained in the radio waves from the positioning satellite. This orbit information is monitored and corrected by a monitoring station on the ground, but before it is corrected, it drifts due to disturbances such as the gravitational forces of the sun and moon and the radiation pressure of sunlight, resulting in errors.

Furthermore, one of the causes of errors in RTK-GPS is errors caused by the influence of obstacles such as buildings. Radio waves from positioning satellites are extremely weak and have properties similar to light, so they can be reflected by obstacles before reaching the GNSS receiver (multipath). This can reduce the positioning accuracy of the GNSS receiver. In particular, radio waves from low-altitude positioning satellites close to the horizon propagate long distances through the Earth's atmosphere, and so propagation errors are often large.

Figure 3 is a diagram showing the functional configuration of the positioning accuracy output system 1 shown in Figure 1.

The GNSS receiver 11 of the construction machine 10 includes a satellite information acquisition unit 111 and a position information acquisition unit 112. The satellite information acquisition unit 111 acquires satellite information from radio waves from the positioning satellite 20. The satellite information includes information on the identification number, position, orbit, and radio wave transmission time of the positioning satellite 20. The satellite information may be acquired in accordance with the NMEA format. The NMEA format is a specification for marine electronic devices such as sonars, anemometers (wind vane and anemometers), and is defined by the Marine Electronics Association. The satellite information acquisition unit 111 outputs the acquired satellite information to the position information acquisition unit 112 and the controller 12. The position information acquisition unit 112 performs positioning based on the satellite information and acquires position information of the construction machine 10. The position information acquisition unit 112 may perform positioning using, for example, the above-mentioned RTK-GPS positioning method. The location information acquisition unit 112 outputs the acquired location information to the controller 12.

The controller 12 of the construction machine 10 acquires the position information (three-dimensional coordinates) of the undercarriage 10a, upper rotating body 10b, or front work machine 10c of the construction machine 10 from the position information from the GNSS receiver 11, and compares it with pre-stored three-dimensional design data or three-dimensional construction data generated from the three-dimensional design data. The controller 12 then automatically controls the operation of the undercarriage 10a, upper rotating body 10b, or front work machine 10c of the construction machine 10 (3D-MC) so that construction is performed according to the three-dimensional design data or three-dimensional construction data, or displays guidance on the monitor 14 (MG). The three-dimensional design data and three-dimensional construction data may be data transmitted in advance from the server device 30 that manages the construction machine 10.

The controller 12 also calculates the positioning accuracy of the construction machine 10 (GNSS receiver 11) based on the satellite information of the positioning satellites 20 output from the GNSS receiver 11, and acquires positioning accuracy information. Specifically, the controller 12 includes a calculation condition setting unit 121, a positioning accuracy calculation unit 122, and a transmission processing unit 123.

The calculation condition setting unit 121 sets the calculation conditions for the positioning accuracy in the positioning accuracy calculation unit 122. The calculation condition setting unit 121 specifies the position information of the construction machine 10 to be calculated and the satellite information of the positioning satellite 20, as well as previously calculated information on the positioning accuracy and the calculation conditions, etc., as the calculation conditions for the positioning accuracy, and sets them in the positioning accuracy calculation unit 122.

The positioning accuracy calculation unit 122 calculates the positioning accuracy of the construction machine 10 based on the above calculation conditions including the satellite information, and acquires the positioning accuracy information. The positioning accuracy calculation unit 122 outputs the acquired positioning accuracy information to the transmission processing unit 123.

In this embodiment, the positioning accuracy calculation unit 122 calculates the Position Dilution of Precision (hereinafter also referred to as "PDOP") as the positioning accuracy, and the calculated PDOP value is used as the positioning accuracy information.

The PDOP is calculated using the Horizontal Dilution of Precision (HDOP) and the Vertical Dilution of Precision (VDOP) as shown in Equation (2).

HDOP and VDOP are indexes of the horizontal and vertical components of PDOP, respectively, and are calculated using methods used in existing satellite positioning systems and are included in the satellite information output from the GNSS receiver 11. The larger the PDOP value, the lower the positioning accuracy, and the smaller the PDOP value, the higher the positioning accuracy. A PDOP value of 1 indicates the highest positioning accuracy. Similarly, for HDOP and VDOP, the larger the respective values, the lower the positioning accuracy, and the smaller the respective values, the higher the positioning accuracy.

In this way, the positioning accuracy output system 1 calculates the position accuracy degradation rate used in existing satellite positioning systems as the positioning accuracy, and uses the value of the position accuracy degradation rate as positioning accuracy information, so that the positioning accuracy can be easily calculated and output without using complicated means. This makes it possible for the positioning accuracy output system 1 to be easily introduced into existing systems including construction machines 10 that use satellite positioning systems. Therefore, the positioning accuracy output system 1 can easily present the state of positioning accuracy to construction companies in an easy-to-understand manner, making it easier to support planned and efficient construction work.

The transmission processing unit 123 transmits the position information of the construction machine 10 and the satellite information of the positioning satellites 20 output from the GNSS receiver 11, the positioning accuracy information acquired by the positioning accuracy calculation unit 122, and the image captured by the camera 15 to the server device 30 via the communication device 13.

The server device 30 is communicatively connected to the construction machine 10, which includes a GNSS receiver 11 that performs positioning based on radio waves from positioning satellites 20 and a controller 12 that calculates the positioning accuracy of the GNSS receiver 11, and outputs the state of the positioning accuracy. The server device 30 determines the state of the positioning accuracy at the position of the construction machine 10 based on the position information of the construction machine 10 transmitted from the construction machine 10, the satellite information of the positioning satellites 20, and the positioning accuracy information, and outputs a symbol according to the determination result. Specifically, the server device 30 includes a memory unit 31, an arrival prediction unit 32, a multipath prediction unit 33, a positioning accuracy prediction calculation unit 34, a positioning accuracy prediction determination unit 35, and an output processing unit 36.

The memory unit 31 is a storage device that stores information transmitted from the construction machine 10 and various information that manages the construction machine 10. The memory unit 31 stores the position information of the construction machine 10, satellite information of the positioning satellite 20, positioning accuracy information (PDOP value), and images captured by the camera 15, all transmitted from the construction machine 10. The memory unit 31 not only stores currently transmitted information as the information transmitted from the construction machine 10, but also stores information transmitted in the past, and accumulates this information.

The memory unit 31 also stores construction information indicating the construction content of the construction machine 10, and surrounding environment information indicating the position and shape of the surrounding environment of the construction machine 10. The construction information of the construction machine 10 includes information on the construction target such as the above-mentioned three-dimensional design data or three-dimensional construction data, as well as information on the construction plan of the construction machine 10, construction progress, and construction accuracy. The surrounding environment information of the construction machine 10 is information on the terrain around the construction machine 10, including the construction site of the construction machine 10, and the positions and shapes of ground objects such as buildings and forests. Of the surrounding environment information, the position and shape of the terrain around the construction machine 10, including the construction site of the construction machine 10, can be obtained from three-dimensional map data. Of the surrounding environment information, the position and shape of ground objects such as buildings and forests can be obtained from three-dimensional construction data that may be included in the construction information.

The arrival prediction unit 32 predicts the arrival of the positioning satellite 20 at the position of the construction machine 10 based on the position information of the construction machine 10 transmitted from the construction machine 10 and the satellite information of the positioning satellite 20. Specifically, the arrival prediction unit 32 acquires information on the current, past, and future positions of the positioning satellite 20 that will arrive at the position of the construction machine 10 from information on the position and orbit of the positioning satellite 20 included in the satellite information of the positioning satellite 20 stored in the memory unit 31. For example, the arrival prediction unit 32 may identify the current and past positions of the positioning satellite 20 that will arrive around or above the construction machine 10 at the position of the construction machine 10. The arrival prediction unit 32 may then predict the future position of the arriving positioning satellite 20 from the current and past positions of the identified positioning satellite 20. The arrival prediction unit 32 outputs information about the current, past, and future positions of the positioning satellites 20 that will arrive at the position of the construction machine 10 to the multipath prediction unit 33 and the positioning accuracy prediction calculation unit 34.

The multipath prediction unit 33 predicts whether or not multipath will occur in the radio waves from the positioning satellite 20 based on the arrival information of the positioning satellite 20 output from the arrival prediction unit 32, the surrounding environment information of the construction machine 10 stored in the memory unit 31, and the captured image of the camera 15. When the multipath prediction unit 33 predicts that multipath will occur in the radio waves from the positioning satellite 20, it identifies the positioning satellite 20 that is the source of the radio waves generating multipath, and sets the positioning accuracy prediction calculation unit 34 so that the satellite information of the identified positioning satellite 20 is excluded from the calculation of the positioning accuracy. The multipath prediction unit 33 outputs the multipath prediction result and the arrival information of the positioning satellite 20 to the positioning accuracy prediction calculation unit 34. Details of the process related to the multipath prediction will be described later with reference to FIG. 5.

The positioning accuracy prediction calculation unit 34 performs a prediction calculation of the positioning accuracy (PDOP) at the position of the construction machine 10 based on information related to the positions of the positioning satellites 20, satellite information, and the predicted results of the multipath. Specifically, the positioning accuracy prediction calculation unit 34 may perform a prediction calculation of the positioning accuracy using the following method.

When calculating the positioning accuracy at the current position of the positioning satellite 20, if it is predicted that no multipath will occur in the radio waves from the positioning satellite 20, the positioning accuracy prediction calculation unit 34 may use the positioning accuracy information transmitted from the construction machine 10 and stored in the memory unit 31 as is.

When calculating the positioning accuracy at the current position of the positioning satellite 20, if it is predicted that multipath will occur in the radio waves from the positioning satellite 20, the positioning accuracy prediction calculation unit 34 may exclude the positioning satellite 20 that is the source of the radio waves that generate multipath, and calculate the positioning accuracy from the satellite information of the positioning satellite 20 that remains after the exclusion.

When calculating the positioning accuracy at the future position of the positioning satellite 20, if it is predicted that no multipath will occur in the radio waves from the positioning satellite 20, the positioning accuracy prediction calculation unit 34 may identify positioning accuracy information at each of the current and past positions of the positioning satellite 20. The positioning accuracy prediction calculation unit 34 may calculate the positioning accuracy at the future position of the positioning satellite 20 from the identified positioning accuracy information at each of the current and past positions of the positioning satellite 20 and the future position of the positioning satellite 20.

When calculating the positioning accuracy at the future position of the positioning satellite 20, if it is predicted that multipath will occur in the radio waves from the positioning satellite 20, the positioning accuracy prediction calculation unit 34 may exclude the positioning satellite 20 that is the source of the radio waves that generate multipath. Positioning accuracy information at each of the current and past positions of the positioning satellite 20 remaining after the exclusion may be identified. The positioning accuracy prediction calculation unit 34 may calculate the positioning accuracy at the future position of the positioning satellite 20 from the positioning accuracy information at each of the current and past positions of the identified positioning satellite 20 and the future position of the positioning satellite 20 remaining after the exclusion.

The positioning accuracy prediction calculation unit 34 outputs the positioning accuracy information (PDOP value) at the current or future position of the positioning satellite 20 that is orbiting the position of the construction machine 10 to the positioning accuracy prediction determination unit 35.

The positioning accuracy prediction determination unit 35 determines the state of positioning accuracy at the position of the construction machine 10 based on the positioning accuracy information output from the positioning accuracy prediction calculation unit 34. Specifically, the positioning accuracy prediction determination unit 35 determines the current or future state of positioning accuracy at the position of the construction machine 10 from the positioning accuracy information at the current or future position of the positioning satellite 20. The state of positioning accuracy is determined by comparing the value of PDOP indicated by the positioning accuracy information output from the positioning accuracy prediction calculation unit 34 with a threshold range of PDOP set in advance for each state of positioning accuracy. The threshold range of PDOP is set in advance, for example, as follows. That is, the threshold range indicating a state of high positioning accuracy is set in advance to a range of PDOP values less than 2. The threshold range indicating a state of medium positioning accuracy is set in advance to a range of PDOP values greater than or equal to 2 and less than 4. The threshold range indicating a state of low positioning accuracy is set in advance to a range of PDOP values greater than or equal to 4.

The positioning accuracy prediction determination unit 35 outputs the determination result of the state of positioning accuracy at the current or future position of the positioning satellite 20 that is orbiting the position of the construction machine 10 to the output processing unit 36.

The output processing unit 36 selects a symbol according to the determination result of the state of positioning accuracy output from the positioning accuracy prediction determination unit 35. This symbol is information indicating the state of positioning accuracy, and may be represented by a figure, an icon, or the like. This symbol is stored in advance in association with the state of positioning accuracy and the threshold range of the PDOP. Details of the process related to the selection of the symbol will be described later with reference to FIG. 4. The output processing unit 36 outputs the selected symbol to the communication device of the server device 30. The communication device of the server device 30 transmits the symbol output from the output processing unit 36 to the terminal device 40. The terminal device 40 displays the symbol transmitted from the server device 30 on the display unit 41.

Thus, the positioning accuracy output system 1 of this embodiment includes a construction machine 10 that performs positioning based on radio waves from a positioning satellite 20, and a server device 30 that is communicatively connected to the construction machine 10 and outputs the state of the positioning accuracy of the construction machine 10. The construction machine 10 is equipped with a GNSS receiver 11 that acquires satellite information including information on the position and orbit of the positioning satellite 20 from the radio waves, performs positioning based on the satellite information, and acquires the position information of the construction machine 10. Furthermore, the construction machine 10 is equipped with a controller 12 that calculates the positioning accuracy based on the satellite information and acquires the positioning accuracy information. The server device 30 judges the state of the positioning accuracy at the position of the construction machine 10 based on the position information, positioning accuracy information, and satellite information transmitted from the construction machine 10, and outputs a symbol 415 according to the judgment result.

As a result, the positioning accuracy output system 1 can easily present the state of the positioning accuracy of the construction machine 10 that uses the satellite positioning system to the construction contractor. This can make it easier for the construction contractor to formulate a plan that enables construction work to be carried out efficiently. Therefore, the positioning accuracy output system 1 can support planned and efficient construction work.

In addition, the positioning accuracy output system 1 determines the state of positioning accuracy based on the predicted arrival of the positioning satellites 20 and outputs a symbol according to the determination result, so that it can predict the future state of positioning accuracy and output a symbol according to the predicted result. This allows the positioning accuracy output system 1 to present the future progress of the state of positioning accuracy to the construction company in an easy-to-understand manner. This makes it easier for the construction company to formulate a plan that allows construction work to be performed more efficiently. Therefore, the positioning accuracy output system 1 can further support planned and efficient construction work.

Figure 4 is a flowchart showing the process for determining the state of positioning accuracy.

In step S401, the server device 30 acquires the position information of the construction machine 10 and the satellite information of the positioning satellite 20 transmitted from the construction machine 10 and stored in the memory unit 31.

In step S402, the server device 30 predicts the future position of the positioning satellite 20 that will arrive at the position of the construction machine 10 based on the position information of the construction machine 10 and the satellite information of the positioning satellite 20.

In step S403, the server device 30 acquires the surrounding environment information stored in the memory unit 31 and the image captured by the camera 15.

In step S404, the server device 30 performs processing related to multipath prediction. This processing will be described later with reference to FIG. 5.

In step S405, the server device 30 performs a prediction calculation of the positioning accuracy (PDOP) at the position of the construction machine 10 based on information related to the positions of the positioning satellites 20, the satellite information, and the predicted results of multipath. As described above, when it is predicted that multipath occurs in the radio waves from the positioning satellites 20, the server device 30 excludes the positioning satellites 20 that are the source of the radio waves generating multipath, and performs a prediction calculation of the positioning accuracy from the satellite information of the positioning satellites 20 that remain after the exclusion.

In step S406, the server device 30 compares the PDOP value acquired in step S405 with the above-mentioned PDOP threshold range to determine the state of the positioning precision (PDOP) at the position of the construction machine 10. If the PDOP value acquired in step S405 is smaller than 2, the server device 30 proceeds to step S407. If the PDOP value acquired in step S405 is equal to or greater than 2 and smaller than 4, the server device 30 proceeds to step S409. If the PDOP value acquired in step S405 is equal to or greater than 4, the server device 30 proceeds to step S411.

In step S407, the server device 30 determines that the positioning accuracy is high and proceeds to step S408.

In step S408, the server device 30 selects a symbol corresponding to the determination result that the positioning accuracy is high, for example, a sunny symbol, and proceeds to step S413.

In step S409, the server device 30 determines that the positioning accuracy is medium and proceeds to step S410.

In step S410, the server device 30 selects a symbol corresponding to the determination result that the positioning accuracy is medium, for example, a cloudy symbol, and proceeds to step S413.

In step S411, the server device 30 determines that the positioning accuracy is low and proceeds to step S412.

In step S412, the server device 30 selects a symbol corresponding to the determination result that the positioning accuracy is low, for example, a rain symbol, and proceeds to step S413.

In step S413, the server device 30 outputs the selected symbol and transmits it to the terminal device 40. The terminal device 40 displays the symbol transmitted from the server device 30 on the display unit 41. The server device 30 can output various information related to the positioning accuracy and the construction site together with the symbol corresponding to the result of the determination of the state of the positioning accuracy, and display it on the display unit 41 of the terminal device 40. Details of the information displayed on the terminal device 40 will be described later with reference to Figures 6 to 9.

Figure 5 is a flowchart showing the process flow for multipath prediction (step S404) shown in Figure 4.

In step S501, the server device 30 checks the surrounding environment information and the captured image of the camera 15 acquired in step S403, and checks the position of the positioning satellite 20 predicted in step S402. Then, based on the surrounding environment information and the captured image, the server device 30 checks the position and shape of terrain such as slopes and ground objects such as buildings that appear in the captured image. Furthermore, based on the position of the positioning satellite 20 and the captured image, the server device 30 checks the position of the positioning satellite 20 in the captured image.

In step S502, the server device 30 determines whether or not an obstacle that blocks radio waves from the positioning satellite 20 is present in the captured image of the camera 15. Specifically, the server device 30 determines whether or not the position of the positioning satellite 20 in the captured image overlaps with a terrain such as a slope or a ground object such as a building that appears in the captured image. If the position of the positioning satellite 20 in the captured image overlaps with a terrain such as a slope or a ground object such as a building that appears in the captured image, the server device 30 determines that the overlapping terrain or ground object is an obstacle that blocks radio waves from the positioning satellite 20. In this case, the server device 30 determines that an obstacle is present in the captured image of the camera 15 and proceeds to step S504. On the other hand, if the position of the positioning satellite 20 in the captured image does not overlap with a terrain such as a slope or a ground object such as a building that appears in the captured image, the server device 30 determines that no obstacle is present in the captured image of the camera 15 and proceeds to step S503.

In step S503, the server device 30 predicts that no multipath occurs in the radio waves from the positioning satellite 20. After that, the server device 30 ends the process shown in FIG. 5 and proceeds to step S405 in FIG. 4.

In step S504, the server device 30 predicts that multipath will occur in the radio waves from the positioning satellite 20.

In step S505, the server device 30 masks the portion determined in step S502 to be an obstacle blocking radio waves from the positioning satellite 20.

In step S506, the server device 30 identifies the positioning satellites 20 included in the masked portion as the positioning satellites 20 that are the source of the radio waves that generate multipath. The server device 30 sets the satellite information of the identified positioning satellites 20 to be excluded from the predicted calculation of the positioning accuracy. The server device 30 then ends the process shown in FIG. 5 and proceeds to step S405 in FIG. 4.

In this way, the positioning accuracy output system 1 predicts whether or not multipath will occur, judges the state of positioning accuracy based on the multipath prediction result, and outputs a symbol according to the judgment result, so that the state of positioning accuracy can be judged more accurately and a symbol according to the judgment result can be output. This allows the positioning accuracy output system 1 to present the exact state of positioning accuracy to the construction company in an easy-to-understand manner. The construction company can accurately formulate a plan that allows construction work to be carried out efficiently. Therefore, the positioning accuracy output system 1 can properly support planned and efficient construction work.

Figure 6 shows a first example of a screen 411 displayed on the display unit 41 of the terminal device 40.

The server device 30 can output various information related to the positioning accuracy and the construction site together with a symbol corresponding to the result of the determination of the state of the positioning accuracy, and display it on the display unit 41 of the terminal device 40. For example, a screen 411 as shown in FIG. 6 is displayed on the display unit 41 of the terminal device 40. The screen 411 shown in FIG. 6 includes a setting item 412 for setting the display contents of the screen 411, and a display image 413 for displaying information related to the positioning accuracy and the construction site. This display image 413 displays a graph 414 showing the progress of the values of VDOP, HDOP, and PDOP, a symbol 415 corresponding to the result of the determination of the state of the positioning accuracy, a work section 416 in the construction site where the construction machine 10 is located, and a work process 417 of the construction machine 10.

Graph 414 is a graph in which one axis, vertical axis 414a, indicates the values of VDOP, HDOP, and PDOP, and the other axis, horizontal axis 414b, indicates time. The larger the VDOP, HDOP, and PDOP values, the lower the positioning accuracy, and the smaller the values, the higher the positioning accuracy. Construction workers who are unfamiliar with values such as PDOP may mistakenly believe that the larger the value of PDOP, the higher the positioning accuracy. Therefore, server device 30 creates graph 414 by inverting the positive and negative directions of one axis, vertical axis 414a, outputs the created graph 414, and displays it on display unit 41 of terminal device 40.

As a result, the positioning accuracy output system 1 can output the progress of the positioning accuracy in a format that is intuitively easy to understand even for construction workers who are unfamiliar with positioning accuracy. Therefore, the positioning accuracy output system 1 can present the state of the positioning accuracy to construction workers in an even easier-to-understand manner, further supporting planned and efficient construction work.

In addition, the display image 413 shown in FIG. 6 displays a graph 414 showing hourly changes in PDOP, etc., for a specific work section 416 in the construction site on a specific work day, hourly symbols 415, and work processes 417 performed on the specific work day in association with each other. This one hour is a predetermined time set in advance within the construction period of the construction machine 10, and is the cycle for determining the state of positioning accuracy and outputting symbols 415. In other words, the server device 30 determines the state of positioning accuracy every predetermined time during the construction period of the construction machine 10, outputs symbols 415 every predetermined time, and displays them on the display unit 41 of the terminal device 40. The server device 30 then outputs the work process 417 of the construction machine 10 in association with the symbols 415, and displays them on the display unit 41 of the terminal device 40.

This allows the positioning accuracy output system 1 to output the relationship between the flow of the work process 417 of the construction machine 10 and the state of positioning accuracy in a format that is intuitively easy for the construction contractor to understand. Therefore, the positioning accuracy output system 1 can easily present the state of positioning accuracy when each work process 417 is performed to the construction contractor, further supporting planned and efficient construction work.

Figure 7 shows a second example of the screen 411 displayed on the display unit 41 of the terminal device 40.

The display image 413 shown in FIG. 7 displays the progress of the symbol 415 at each predetermined time in each of the multiple work sections 416 within the construction site. In other words, the server device 30 determines the state of positioning accuracy in each of the multiple work sections 416 within the construction site of the construction machine 10, outputs the symbol 415 for each work section 416, and displays it on the display unit 41 of the terminal device 40.

Therefore, the positioning accuracy output system 1 can output the differences in the positioning accuracy state for each work section 416 in a format that is intuitively easy for the construction worker to understand. Therefore, the positioning accuracy output system 1 can present the differences in the positioning accuracy state for each work section 416 in an easy-to-understand manner for the construction worker, further supporting planned and efficient construction work.

Figure 8 shows a third example of a screen 411 displayed on the display unit 41 of the terminal device 40.

The display image 413 shown in FIG. 8 displays a map image 418 of the construction site, as well as work sections 416 within the construction site and symbols 415 for each work section 416, superimposed on the map image 418. The map image 418 is not limited to a still image, and may be a moving image. The display image 413 shown in FIG. 8 displays a time setting toolbar 419 for displaying the map image 418 and symbols 415 at any time during the construction period. In other words, the server device 30 outputs the symbols 415 for each work section 416 superimposed on the map image 418 of the construction site of the construction machine 10, and displays them on the display unit 41 of the terminal device 40.

This allows the positioning accuracy output system 1 to output the relationship between the environment and work conditions at the construction site and the state of positioning accuracy in a format that is intuitively easy for construction workers to understand. Therefore, the positioning accuracy output system 1 can present the state of positioning accuracy to construction workers in an easy-to-understand manner while comparing it with the environment and work conditions at the construction site, further supporting planned and efficient construction work.

Figure 9 shows a fourth example of a screen 411 displayed on the display unit 41 of the terminal device 40.

In the screen 411 shown in FIG. 9, a setting item 412 for setting the display contents of the screen 411 may be operated to display a display image 420 displaying the arrival status of the positioning satellite 20 instead of a display image 413 displaying information about the positioning accuracy and the construction site. The display image 420 shown in FIG. 9 is provided with a celestial image 422 on which the position 421 of the positioning satellite 20 at a certain location and at a certain time is plotted, and a time setting toolbar 423 for displaying the celestial image 422 at any time. The display image 420 may display the type, position, and orbit of the positioning satellite 20 at any location and any time specified by the construction company. That is, the server device 30 can output the type, position, and orbit of the positioning satellite 20 at any location and any time specified by the construction company by operating the terminal device 40, and display it on the display unit 41 of the terminal device 40.

As a result, the positioning accuracy output system 1 can output the positions and number of positioning satellites 20 captured when positioning the construction machine 10 in a format that is intuitively easy for the construction worker to understand. Therefore, the positioning accuracy output system 1 can clearly show the construction worker which positioning satellite 20 is used to obtain the position information of the construction machine 10 and ensure the positioning accuracy, further supporting planned and efficient construction work.

In the above embodiment, the server device 30 outputs various information related to the positioning accuracy, such as the symbol 415, and displays it on the display unit 41 of the terminal device 40, but this is not limited to the above, and the information may be displayed on the monitor 14 of the construction machine 10.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various design modifications can be made without departing from the spirit of the present invention described in the claims. The present invention allows the configuration of one embodiment to be added to the configuration of another embodiment, the configuration of one embodiment to be replaced with another embodiment, or part of the configuration of one embodiment to be deleted.

1... Positioning accuracy output system, 10... Construction machine, 11... GNSS receiver, 12... Controller, 15... Camera, 20, 20a to 20d... Positioning satellites, 30... Server device, 414... Graph, 415... Symbol, 416... Work area, 417... Work process, 418... Map image

Claims (4)

A positioning accuracy output system including: a construction machine that performs positioning based on radio waves from a positioning satellite; and a server device that is communicatively connected to the construction machine and outputs a state of the positioning accuracy of the construction machine,
The construction machine includes:
a GNSS receiver that acquires satellite information including information regarding the position and orbit of the positioning satellite from the radio waves, performs positioning based on the satellite information, and acquires position information of the construction machine;
a controller for calculating the positioning accuracy based on the satellite information and acquiring positioning accuracy information;
The controller calculates a position accuracy degradation rate as the positioning accuracy, and sets the value of the position accuracy degradation rate as the positioning accuracy information.
The server device includes:
predicting the arrival of the positioning satellite at the position of the construction machine based on the satellite information and the position information transmitted from the construction machine, determining the state of the positioning accuracy at the position of the construction machine based on the positioning accuracy information and the arrival prediction, and outputting a symbol according to the determination result;
a graph in which one axis indicates the value of the position accuracy degradation rate and the other axis indicates time, is created by inverting the positive and negative directions of one of the axes, and the created graph is output. The construction machine is equipped with a camera that captures images of the surroundings and the sky above the construction machine,
The positioning accuracy output system according to claim 1, characterized in that the server device predicts whether or not multipath will occur in the radio waves based on the surrounding environment information of the construction machine, the camera image transmitted from the construction machine, and the arrival prediction, determines the state of the positioning accuracy based on the prediction result of the multipath , and outputs the symbol according to the determination result. A positioning accuracy output system including: a construction machine that performs positioning based on radio waves from a positioning satellite; and a server device that is communicatively connected to the construction machine and outputs a state of the positioning accuracy of the construction machine,
The construction machine includes:
a GNSS receiver that acquires satellite information including information regarding the position and orbit of the positioning satellite from the radio waves, performs positioning based on the satellite information, and acquires position information of the construction machine;
a controller for calculating the positioning accuracy based on the satellite information and acquiring positioning accuracy information;
The server device includes:
predicting the arrival of the positioning satellite at the position of the construction machine based on the satellite information and the position information transmitted from the construction machine, determining the state of the positioning accuracy at the position of the construction machine based on the positioning accuracy information and the arrival prediction, and outputting a symbol according to the determination result;
A positioning accuracy output system characterized by determining the state of the positioning accuracy at each predetermined time during a construction period of the construction machine, outputting the symbol at each predetermined time, and outputting the work process of the construction machine in association with the symbol. A positioning accuracy output system including: a construction machine that performs positioning based on radio waves from a positioning satellite; and a server device that is communicatively connected to the construction machine and outputs a state of the positioning accuracy of the construction machine,
The construction machine includes:
a GNSS receiver that acquires satellite information including information regarding the position and orbit of the positioning satellite from the radio waves, performs positioning based on the satellite information, and acquires position information of the construction machine;
a controller for calculating the positioning accuracy based on the satellite information and acquiring positioning accuracy information;
The server device includes:
predicting the arrival of the positioning satellite at the position of the construction machine based on the satellite information and the position information transmitted from the construction machine, determining the state of the positioning accuracy at the position of the construction machine based on the positioning accuracy information and the arrival prediction, and outputting a symbol according to the determination result;
A positioning accuracy output system characterized by determining the state of the positioning accuracy in each of a plurality of work sections within a construction site of the construction machine, and outputting the symbol by superimposing it for each work section on a map image of the construction site of the construction machine.

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