Topographical information management system

Abstract

To provide a topographical information management system with which, by taking into account a change of the correctness of measurement accuracy per sensor, it is possible to more accurately synthesize topographical information measured by a plurality of sensors.SOLUTION: A topographical information management system according to the present invention comprises a plurality of topographical measurement devices for measuring a topography and generating topographical information, and a server device for aggregating and processing the topographical information. The server device includes: a measurement point distance calculation unit for calculating the distance between the installed position of a terrain measurement device and a measurement point at which terrain measurement is taken; a measurement reliability estimation unit for estimating the measurement reliability of the terrain measurement device per measurement point on the basis of the measurement accuracy information per terrain measurement device and the distance information; and a topographical information synthesis unit for synthesizing the topographical information generated by a plurality of terrain measurement devices on the basis of the measurement reliability.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a topographical information management system for managing information relating to topography. [Background technology]

[0002] At civil engineering construction sites, development is underway on a system that manages wide-area current terrain information in real time by synthesizing terrain information measured by multiple sensors installed on work machines such as hydraulic excavators and on-site structures. Various practical applications are expected, such as efficient excavation control of construction machines according to the current terrain and construction progress management based on changes in the current terrain.

[0003] To accurately combine topographical information measured by multiple sensors installed on-site, it is necessary to consider the accuracy (reliability) of each individual piece of topographical information. The accuracy of topographical information varies depending on the position of the target topography relative to the sensor, the time of measurement, and the condition and performance of the sensor that measured it. In particular, in areas where topographical information is obtained redundantly by multiple sensors, selecting and combining the more accurate topographical information will ensure that the topographical information generated after the combination is also accurate.

[0004] As a means for synthesizing topographical information by taking into consideration the accuracy of each piece of measurement data, a technique such as that disclosed in Patent Document 1 is disclosed. Patent Document 1 discloses a technique for synthesizing topographical information based on priorities set by accuracy information in measurement data from multiple sensors. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6289731 specification Summary of the Invention [Problem to be solved by the invention]

[0006] To accurately combine measurement data from multiple sensors, it is necessary to accurately understand the measurement accuracy of each sensor. In particular, the variation in sensor measurement accuracy tends to increase the farther the measurement point is from the sensor. Therefore, even within the measurement data of a single sensor, the accuracy (reliability) of topographical information varies depending on the distance.

[0007] The technology disclosed in Patent Document 1 determines the priority by focusing on the measurement accuracy of each individual sensor, but does not consider the variation in accuracy within the measurement data of a single sensor. Therefore, there is a risk that, among the measurement data of a certain sensor that is determined to have the highest accuracy, data with low accuracy may end up being given a higher priority.

[0008] The present invention aims to provide a topographical information management system that can more accurately combine topographical information measured by multiple sensors by taking into account variations in the accuracy (reliability) of measurement precision for each sensor. [Means for solving the problem]

[0009] In order to solve the above problems, a topographic information management system according to the present invention comprises a plurality of topographic measurement devices that measure topography and generate topographic information, and a server device that aggregates and processes the topographic information. The server device comprises a measurement point distance calculation unit that calculates the distance between the installation position of the topographic measurement device and the measurement point where the topography was measured to generate distance information, a measurement reliability estimation unit that estimates the measurement reliability of the topographic measurement device at the measurement point based on the measurement accuracy information and distance information for each topographic measurement device, and a topographic information synthesis unit that synthesizes the topographic information generated by the plurality of topographic measurement devices based on the measurement reliability. [Effects of the Invention]

[0010] According to the present invention, the measurement reliability of the topographical information measured by each sensor at each measurement point is estimated based on the distance information between the installation position of each sensor and each measurement point where the sensor measured the topographical information. In addition, by taking into account the measurement reliability estimated for each sensor for each measurement point, it becomes possible to synthesize topographical information more accurately. Further features related to the present invention will become apparent from the description of the present specification and the accompanying drawings. Furthermore, problems, configurations, and effects other than those described above will become apparent from the following description of the embodiments. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a diagram showing an overview of a topographical information management system according to a first embodiment; [Figure 2] FIG. 2 is a diagram showing the processing functions of the topographical information management system according to the first embodiment. [Figure 3] FIG. 4 is a diagram showing an example of distance information DI calculated by a measurement point distance calculation unit according to the first embodiment. [Figure 4] FIG. 4 is a diagram showing an example of measurement reliability CI calculated by a measurement reliability estimating unit according to the first embodiment. [Figure 5] FIG. 3 is a diagram showing an example of topographical information EI synthesized by a topographical information synthesis unit according to the first embodiment. [Figure 6] FIG. 3 is a diagram showing a processing flow of the server device 10 according to the first embodiment. [Figure 7] FIG. 1 is a diagram showing the effects of the invention according to the first embodiment. [Figure 8] FIG. 10 is a diagram showing an example of measurement reliability CI calculated by a measurement reliability estimating unit according to the second embodiment. [Figure 9] FIG. 10 is a diagram showing the effect of the invention according to the second embodiment. [Figure 10] FIG. 10 is a diagram showing the processing functions of a topographical information management system according to a third embodiment. [Figure 11] FIG. 11 is a diagram showing an example of history information TAB stored in a topographical information history storage unit according to the third embodiment. [Figure 12] FIG. 10 is a diagram showing a processing flow of the server device 10 according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The following description shows specific examples of the contents of the present invention, and the present invention is not limited to these descriptions. Various changes and modifications are possible by those skilled in the art within the scope of the technical ideas disclosed in this specification. Furthermore, in all drawings used to explain the present invention, parts having the same function are designated by the same reference numerals, and repeated description thereof may be omitted.

[0013] [Example 1] 1 is a diagram illustrating an overview of a topographical information management system 500 according to Example 1. The topographical information management system 500 includes a topographical measurement device 1 attached to an external measurement system 100, a topographical measurement device 4 attached to a machine 200, a communication facility 8, a user interface 9, a server device 10, and the like.

[0014] The off-vehicle measurement system 100 includes a topographic measurement device 1, an information processing device 2, and a communication terminal 3, and is installed on pillars and walls within a construction site. In this embodiment, the topographic measurement device 1 is assumed to be equipped with a stereo camera or LiDAR (Light Detection and Ranging) capable of measuring the three-dimensional shape of the topography. The information processing device 2 includes, for example, a CPU (Central Processing Unit) and memory, and realizes various information processing functions by the CPU executing programs stored in the memory. Note that the number of topographic measurement devices 1 provided in the off-vehicle measurement system 100 is not limited to one, and multiple or multiple types of measurement devices may be installed and integrated and processed by the information processing device 2. Hereinafter, data measured by the stereo camera or LiDAR will be referred to as topographic information EI. The data measured by the topographic measurement device 1 is processed by the information processing device 2 and transmitted from the communication terminal 3 to the server device 10 via communication equipment 8.

[0015] The machine 200 includes all kinds of machines that perform work at a construction site, such as construction machines and transport vehicles. In this embodiment, a hydraulic excavator 200a and a wheel loader 200b are illustrated as examples of the machine 200, but the types of machine 200 that can be assumed are not limited to these two types, and all kinds of construction machines and transport vehicles are assumed.

[0016] A hydraulic excavator 200a, which is one of the machines 200, has a terrain measurement device 4a, a machine condition measurement device 5a, an information processing device 6a, and a communication terminal 7a. In this embodiment, it is assumed that the terrain measurement device 4a is equipped with a stereo camera, LiDAR, or the like, which is capable of measuring the three-dimensional shape of terrain information. The number of terrain measurement devices 4a equipped in the external measurement system is not limited to one, and multiple or different types of measurement devices may be installed and integrated and processed by the information processing device 6a. In this embodiment, the machine condition measurement device 5a is configured to use at least two GNSS (Global Navigation Satellite System) antennas and at least one IMU (Inertial Measurement Unit), and to calculate the three-dimensional position of the upper rotating body 201a of the hydraulic excavator 200a in the horizontal and vertical directions, and the three-dimensional attitude in the roll, pitch, and yaw directions. The data measured by the topography measuring device 4a and the machine condition measuring device 5a are integrated and processed by an information processing device 6a and transmitted from a communication terminal 7a to a server device 10 via a communication facility 8. Reference numeral 203a denotes a lower running body.

[0017] A wheel loader 200b, another of the machines 200, has a terrain measurement device 4b, a machine state measurement device 5b, an information processing device 6b, and a communication terminal 7b. The details of each component are the same as those of the hydraulic excavator 200a, so detailed description will be omitted.

[0018] The communication equipment 8 includes a communication terminal 3 provided in the external measurement system 100 and a communication terminal 7 provided in the machine 200. The communication equipment 8 is equipment that enables all controllers and sensors within the construction site to be connected to the same network, and is composed of wireless LAN (Local Area Network) access points, etc.

[0019] The server device 10 is a computer connected to the communication network of the communication equipment 8. In this embodiment, the server device 10 is provided in the office 300 and is connected to a user interface 9 (for example, a personal computer or a tablet terminal) for receiving input from a user or displaying and outputting the results of integrated processing of measurement data. The server device 10 may be prepared as a virtual machine on the cloud and configured to be able to communicate with the cloud via the network provided by the communication equipment 8. The server device 10 may also be configured to be mounted on one of the machines 200 at the construction site.

[0020] 2 is a diagram showing the processing functions of the topographical information management system 500 according to Example 1. The overall processing of the topographical information management system 500 is configured by the processing functions of the outside-vehicle measurement system 100, the machine 200, the user interface 9, and the server device 10.

[0021] The off-vehicle measurement system 100 includes a topographic measurement device 1 such as a camera / LiDAR, an information processing device (controller) 2, and a communication terminal 3. Processing in the off-vehicle measurement system 100 is executed by the information processing device 2. The information processing device 2 is composed of a measurement state storage unit 2a and an integrated processing unit 2b. The measurement state storage unit 2a stores the measurement state MS of each topographic measurement device 1. The measurement state MS includes the measurement position and orientation MSa and measurement performance MSb.

[0022] The measurement position and attitude MSa is an index that indicates the position and attitude of the topographic measurement device 1 measured in advance by surveying or the like, using a coordinate system defined within the construction site (hereinafter referred to as the on-site coordinate system) as a reference, in a total of six dimensions, including three-dimensional position and three-dimensional attitude. The measurement performance MSb indicates the performance of the sensor installed in the topographic measurement device 1 using a constant value classified into levels such as low, medium, and high. Note that the measurement performance may be calculated as a real value as numerical data based on the variation of the sensor, etc. Furthermore, the measurement performance MSb corresponds to the measurement accuracy information in the claims, and more specifically, the measurement accuracy information referred to here includes the camera resolution, the number of beams per LiDAR, measurement variation, etc. Note that the measurement position and attitude MSa may be configured so that the external measurement system 100 is equipped with a GNSS, an IMU, etc., and the position and attitude of the topographic measurement device 1 are directly measured.

[0023] The integration processing unit 2b integrates the topography information EI measured by the topography measurement device 1 mounted on the external measurement system 100 and the measurement state MS output by the measurement state memory unit 2a, generates transmission data processed into a format that can be transmitted, and transmits the transmission data to the server device 10 via the communication terminal 3 and communication equipment 8.

[0024] The machine 200 has a terrain measurement device 4 such as a camera / LiDAR, a machine state measurement device 5 such as a GNSS / IMU, an information processing device (controller) 6, and a communication terminal 7. Processing in the machine 200 is executed by the on-board information processing device 6. The information processing device 6 is composed of a measurement state memory unit 6c, a measurement state calculation unit 6d, and an integrated processing unit 6e. The measurement state memory unit 6c stores the vehicle body measurement state MMS of each terrain measurement device 4 mounted on the machine 200. The vehicle body measurement state MMS includes the vehicle body measurement position and attitude MMSa and measurement performance MSb. The vehicle body measurement position and attitude MMSa indicates the installation position and attitude of the terrain measurement device 4 measured in advance by surveying or the like, using a coordinate system defined on the upper rotating body 201a of the machine 200 (hereinafter referred to as the machine coordinate system) as the reference, in a total of six dimensions, including a three-dimensional position and a three-dimensional attitude.

[0025] The measurement state calculation unit 6d calculates the vehicle body position and attitude of the upper rotating body 201a relative to the on-site coordinate system from the measurement results of the GNSS and IMU, and also converts the vehicle body measurement position and attitude MMSa into the on-site coordinate system based on the calculated vehicle body position and attitude, and calculates the measurement state MS of each topography measurement device 4 relative to the on-site coordinate system. The function of the integration processing unit 6e is similar to that of the integration processing unit 2b of the outside-vehicle measurement system 100, so a detailed description will be omitted.

[0026] The server device 10 is configured, for example, by a computer equipped with a CPU (Central Processing Unit) and memory, and performs the functions described below by the CPU executing programs stored in the memory. The server device 10 has, as its functional units, a topographical information acquisition unit 10a, a measurement point distance calculation unit 10b, a measurement reliability estimation unit 10c, and a topographical information synthesis unit 10d. The topographical information acquisition unit 10a receives topographical information EI transmitted from the external measurement system 100 and the machine 200, and stores the topographical information EI in a linked state with the identifiers of the topographical measurement devices 1 and 4 that transmitted it. The measurement point distance calculation unit 10b calculates and stores distance information DI of each topographical measurement device 1 and 4 for each gridded measurement point based on the topographical information EI measured by each topographical measurement device 1 and 4 and the measurement state MS.

[0027] 3 is a diagram showing an example of distance information DI calculated by the measurement point distance calculation unit 10b according to the first embodiment. Here, distance information DI calculated for the topography measurement device 1 mounted on the outside-vehicle measurement system 100 is shown as an example. In this embodiment, it is assumed that the synthesis range MA is determined in advance and stored in the measurement point distance calculation unit 10b.

[0028] The composite range MA is gridded at a certain resolution, and for each cell where topography information EI exists, the distance from the installation position of the topography measuring device 1 is calculated, and distance information DI is generated with the calculated distance stored in the map information. The value stored in each cell of the distance information DI is calculated as the three-dimensional distance between the corresponding cell and the topography measuring device 1 as a positive real number, but in the example of Figure 3, for ease of explanation, it is written in the cell as an integer value. The distance information DI is generated so that the farther the cell is from the topography measuring device 1, the larger the numerical value in the cell.

[0029] Returning to Fig. 2, the measurement reliability estimation unit 10c estimates the degree of measurement reliability CI for each gridded measurement point based on the measurement performance MSb of each topography measurement device 1, 4 and the distance information DI calculated for each topography measurement device 1, 4. Here, measurement reliability CI is an index that indicates how reliable the measurement results are when a certain topography measurement device 1, 4 measures the topography at a certain measurement point, and is expressed as a real value between 0 and 1, for example (the larger the number, the higher the reliability).

[0030] 4A and 4B are diagrams showing an example of measurement reliability CI calculated by the measurement reliability estimation unit 10c according to the first embodiment. Here, Fig. 4A shows an example of measurement reliability CIa estimated for the topography measurement device 1a mounted on the outside-vehicle measurement system 100a, and Fig. 4B shows an example of measurement reliability CIb estimated for the topography measurement device 1b mounted on the outside-vehicle measurement system 100b. In this embodiment, it is assumed that the synthesis range MA is determined in advance and stored in the measurement reliability estimation unit 10c.

[0031] The measurement reliability CI is calculated based on the measurement performance MSb and the distance information DI. For example, for the n-th topographic measurement device 1, 4, the measurement reliability CI of the i-th cell is calculated as shown in Equation 1 below.

[0032]

number

[0033] In Figure 4(a), the composite range MA is gridded at a certain resolution, as in Figure 3, and measurement reliability CIa is generated for each cell where topographic information EIa exists, based on measurement performance MSb and distance information DIa. In this embodiment, the value of measurement reliability CIa stored in each cell is estimated to increase as the distance information DIa decreases. Furthermore, in this embodiment, it is assumed that the topographic measurement device 1a is a sensor with high measurement performance MSb, so the value of measurement reliability CIa is higher overall than measurement reliability CIb.

[0034] In Fig. 4(b), the composite range MA is gridded at a certain resolution as in Fig. 3, and measurement reliability CIb is generated for each cell that contains topography information EIb based on measurement performance MSb and distance information DIb. In this embodiment, it is assumed that the topography measurement device 1b has a sensor with lower measurement performance MSb than the topography measurement device 1a, so the value of measurement reliability CIb is generally lower than the measurement reliability CIa.

[0035] Returning to Fig. 2, the topographic information synthesis unit 10d synthesizes the topographic information EI generated by the multiple topographic measurement devices based on the measurement reliability CI estimated for each of the topographic measurement devices 1 and 4, to generate synthetic topographic information SEI. The generated synthetic topographic information SEI is visualized on a user interface 9 equipped with a display for display.

[0036] To summarize the configuration of the topographic information management system in this embodiment, the topographic information management system 500 includes a plurality of topographic measurement devices 1, 4 that measure the topography and generate topographic information, and a server device 10 that aggregates and processes the topographic information. The server device 10 includes a measurement point distance calculation unit 10b that calculates the distance between the installation positions of the topographic measurement devices 1, 4 and the measurement points where the topography was measured to generate distance information, a measurement reliability estimation unit 10c that estimates the measurement reliability of the topographic measurement device for each measurement point based on the measurement accuracy information and distance information for each topographic measurement device 1, 4, and a topographic information synthesis unit 10d that synthesizes the topographic information generated by the plurality of topographic measurement devices based on the measurement reliability.

[0037] Fig. 5 is a diagram showing an example of topographic information EI synthesized by the topographic information synthesis unit 10d according to Example 1. Fig. 5 shows an example in which topographic information EIa and EIb are synthesized based on the reliability CIa of the topographic measuring device 1a shown in Fig. 4(a) and the reliability CIb of the topographic measuring device 1b shown in Fig. 4(b).

[0038] In this embodiment, the topographical information EI represents the elevation information at the point indicated by each cell. When multiple pieces of topographical information EI and reliabilities CI are stored for each cell, the combined topographical information SEI is calculated by a weighted average as shown in the following equation 2. That is, the topographical information combining unit 10d combines the topographical information for each measurement point using a weighted average with the measurement reliability CI as the weight.

[0039]

number

[0040] Each gridded cell in Figure 5 shows which information is dominant in the combined topography information SEI, the topography information EIa from the topography measurement device 1a or the topography information EIb from the topography measurement device 1b, i.e., whether it is combined with a higher reliability CI. Diagonally shaded (downward to the right) cells indicate that the topography information EIa is dominant, diagonally shaded (downward to the left) cells indicate that the topography information EIb is dominant, and shaded cells indicate that the topography information EIa and EIb are equally dominant. Basically, the combination is performed so that the cell closer to each of the topography measurement devices 1a and 1b is dominant. However, because the measurement performance MSb of the topography measurement device 1a is higher than that of the topography measurement device 1b, there are many cells in which the topography information EIa is dominant.

[0041] FIG. 6 is a diagram showing a processing flow executed by the server device 10 according to the first embodiment. First, in FC1a, the topographical information acquisition unit 10a acquires topographical information EI and measurement status MS transmitted from the external measurement system 100 and the machine 200 for the plurality of topographical measurement devices 1 and 4. Next, in FC2a, the measurement point distance calculation unit 10b selects one of the topographical measurement devices 1 and 4 that transmitted the topographical information EI and measurement status MS to the server device 10. Next, in FC3a, the measurement point distance calculation unit 10b selects one cell to be calculated from the gridded cell group. Next, in FC4a, the measurement point distance calculation unit 10b calculates distance information DI between the selected topographical measurement device 1 and 4 and the selected cell. Next, in FC5a, the measurement reliability estimation unit 10c estimates measurement reliability CI based on the measurement performance MSb and distance information DI of the selected topographical measurement device 1 and 4.

[0042] After the calculation of the measurement reliability CI is completed, FC6a determines whether the calculation of the measurement reliability CI has been completed for all cells, and if there are any cells for which calculation has not yet been completed, the process returns to FC3a. If calculation of all cells has been completed, FC7a determines whether the calculation of the measurement reliability CI has been completed for all topographic measurement devices 1, 4 that have transmitted data to the server device 10. If there are any topographic measurement devices 1, 4 for which calculation has not yet been completed, the process returns to FC2a. Note that the process of FC7a may be executed by either the measurement point distance calculation unit 10b or the measurement reliability estimation unit 10c.

[0043] If the calculation of measurement reliability CI has been completed for all cells and the topography measurement devices 1 and 4, the topography information synthesis unit 10d synthesizes the topography information EI based on the estimated measurement reliability CI in FC8a to generate synthesized topography information SEI. The synthesized topography information SEI is output from the topography information synthesis unit 10d to the topography information visualization unit 9a provided in the user interface 9 in FC9a.

[0044] Figure 7 is a diagram showing the effects of the invention according to Example 1. Figure 7(a) shows two topographic measurement devices 1a and 1b installed facing each other, measuring a synthesis range MA, similar to Figure 5. To simplify the explanation, the following will show a comparison between the synthesis results of topographic information EI and measurement reliability CI in the black-hued cells.

[0045] 7(b) shows a graph comparing the results of a comparative example in which the priorities for the topography information EI at each measurement point were determined and synthesized based only on the measurement performance MSb of the topography measurement devices 1 and 4, with the results of this embodiment in which the priorities were determined based on the measurement performance MSb and distance information DI. In this graph, the topography information EIa measured by the topography measurement device 1a is shown by a white circle, and the topography information EIb measured by the topography measurement device 1b is shown by a black circle, and it is assumed that although the same topography was measured, there was some error due to errors in the installation position and orientation, device performance, etc.

[0046] In FIG. 7(b), the results of combining topographic information EI using the comparative example are indicated by triangles. In the comparative example, the topographic information was combined using only the measurement performance MSb, so the topographic information EIa from the topographic measurement device 1a, which has high measurement performance MSb, is weighted heavily overall. On the other hand, the results of combining topographic information EI using this embodiment are indicated by squares. In this embodiment, as described above, measurement reliability CI is estimated using distance information DI in addition to measurement performance MSb, and this measurement reliability CI is used to combine the topography. In other words, the higher the measurement reliability CI, the greater the weighting applied to combine the topography. Therefore, the topographic information EIa is weighted heavily at the measurement points on the left side of the graph that are closer to the topographic measurement device 1a, and the topographic information EIb is weighted heavily at the measurement points on the right side of the graph that are closer to the topographic measurement device 1b.

[0047] Figure 7(c) shows the measurement reliability CI estimated at each measurement point. The measurement reliability CIa estimated for the topographic measurement device 1a is shown as a white circle, and the measurement reliability CIb estimated for the topographic measurement device 1b is shown as a black circle. The estimation results follow the results in Figure 4, and the measurement reliability CI is large at measurement points that are close to each other for the topographic measurement devices 1a and 1b. However, since it is assumed that the measurement performance MSb of the topographic measurement device 1a is high, the measurement reliability CI value is large overall.

[0048] FIG. 7(c) also shows the measurement reliability CI of the combined topographic information EI in the comparative example and this embodiment. This is an index showing how reliable the combined topographic information EI is, rather than the measurement reliability of the topographic measurement device alone. The measurement reliability CI of the combined topographic information EI in the comparative example is indicated by a triangle, while the measurement reliability CI of the combined topographic information EI in this embodiment is indicated by a square. At the measurement point on the left, close to the topographic measurement device 1a, the measurement reliability CI of both the comparative example and this embodiment is high due to the influence of the high measurement reliability CIa of the topographic measurement device 1a. However, compared to the comparative example, in which the measurement reliability CI is determined based only on the measurement performance MSb, the measurement reliability CI of the combined topographic information SEI in this embodiment, in which the measurement reliability CI is determined based on two pieces of information, the measurement performance MSb and the distance information DI, is higher.

[0049] Furthermore, at the measurement point on the right side close to the topography measuring device 1b, the measurement reliability CIa of the topography measuring device 1a is low, and so the measurement reliability CI of both the comparative example and this example is low. However, this example, which estimates the measurement reliability CI of the topography measuring device 1b higher based on the distance information DI, has a higher measurement reliability CI of the composite topography information SEI.

[0050] As described above, according to this embodiment, by estimating the measurement reliability CI by taking into account the distance information DI in addition to the measurement performance MSb of the topographic measurement device, it is possible to select and synthesize more reliable topographic information EI throughout the entire synthesis range MA, thereby generating more accurate synthesized topographic information SEI.

[0051] In this embodiment, it is assumed that two topography measuring devices 1 are installed facing each other, but the application of this embodiment is not limited to this, and it can also be applied to a situation where two topography measuring devices 1 are facing in directions that are 90 degrees apart from each other, or to a situation where three or more topography measuring devices 1 are installed.

[0052] [Example 2] Next, a topographical information management system according to a second embodiment will be described with reference to Figures 8 and 9. In the topographical information management system according to the second embodiment, the configuration of each component is the same as in the first embodiment, and therefore a description thereof will be omitted. The second embodiment differs from the first embodiment in that, while the first embodiment assumes topographical measurement using a topographical measurement device installed in an off-vehicle measurement system 100 that is fixedly installed on-site, the second embodiment assumes topographical measurement using a topographical measurement device installed in an operating machine 200, and therefore the amount of information to be handled is increased. More specifically, in this embodiment, the vehicle body measurement status MMS output by the machine 200 includes the vehicle body measurement position and attitude MMSa and measurement performance MSb, as well as the measurement position and attitude reliability MSc and the operating speed MSd. The measurement position and attitude reliability MSc is an index that indicates the reliability of the vehicle body measurement position and attitude MMSa (an index that indicates the position and attitude of the terrain measurement device 1 in a total of six dimensions, including three-dimensional position and three-dimensional attitude), and is calculated from the GNSS satellite reception status used to calculate the vehicle body measurement position and attitude MMSa, measurement variations of the GNSS and IMU, etc., and is shown as a constant value classified into levels such as low, medium, and high. The operating speed MSd represents the operating speed when the machine 200 is operating, and is calculated from the amount of change per time in the position and attitude of the machine 200 measured by GNSS and the rotational speed acquired by the IMU, and is shown as a real number representing the magnitude of the speed.

[0053] In this embodiment, the measurement reliability estimation unit 10c estimates the measurement reliability CI based on the measurement position and orientation reliability MSc and the motion speed MSd in addition to the measurement performance MSb and distance information DI. Fig. 8 is a diagram showing an example of the measurement reliability CI calculated by the measurement reliability estimation unit 10c according to the second embodiment. Figs. 8(a) and 8(b) show the measurement reliability CI estimated for the topography measurement device 4 mounted on the machine 200. In this embodiment as well, it is assumed that the synthesis range MA is determined in advance and stored in the measurement reliability estimation unit 10c.

[0054] The measurement reliability CI is calculated based on the measurement position and orientation reliability MSc and the operation speed MSd in addition to the measurement performance MSb and distance information DI as described above. For example, for the n-th topographic measurement device 1, 4, the measurement reliability CI of the ith cell is calculated as shown in Equation 3 below.

[0055]

number

[0056] The topography measurement device 4 in Fig. 8(a) has high measurement performance MSb equivalent to that of the topography measurement device 1a shown in Fig. 4(a), but is mounted on a machine 200 rather than on an external measurement system 100, so it is assumed that the measurement position and orientation reliability MSc is slightly lower. In this case, the value of measurement reliability CI shown in Fig. 8(a) is estimated to be lower overall compared to the value of measurement reliability CIa shown in Fig. 4(a).

[0057] The topography measurement device 4 in Fig. 8(b) has high measurement performance MSb and measurement position and attitude reliability MSc equivalent to those of the topography measurement device 4 shown in Fig. 8(a), but it is assumed that the machine 200 is turning clockwise and the operating speed MSd is increasing. In this case, the values ​​of measurement reliability CI shown in Fig. 8(b) are estimated to be even lower overall compared to the values ​​of measurement reliability CI shown in Fig. 8(a).

[0058] Figure 9 is a diagram showing the effects of the present invention according to this embodiment. Figure 9(a) shows how two machines 100a and 100b are equipped with topographic measurement devices 4a and 4b, which are installed facing each other and measuring a synthesis area MA. Here, it is assumed that the measurement performance MSb and measurement position and orientation reliability MSc of the topographic measurement devices 4a and 4b are equivalent, but the operating speed MSd of the topographic measurement device 4b is greater. To simplify the explanation below, a comparison of the synthesis results of topographic information EI and measurement reliability CI in the black-shaded cells is shown.

[0059] Figure 9(b) shows the measurement reliability CI estimated at each measurement point. The measurement reliability CIa estimated for the topography measurement device 4a is shown as a white circle, and the measurement reliability CIb estimated for the topography measurement device 4b is shown as a black circle. The estimation results follow the results in Figure 8, and the measurement reliability CI is large at measurement points that are close to each other for the topography measurement devices 4a and 4b. However, the measurement reliability CI value for the topography measurement device 4b is generally low because it is assumed that the operating speed MSd is high.

[0060] FIG. 9(b) is a graph showing the measurement reliability of the topographic information synthesized by the methods of this embodiment and Example 1 for the situation in FIG. 9(a). In FIG. 9(b), the measurement reliability CI of the topographic information EI synthesized by the method of Example 1 is indicated by a triangle, and the measurement reliability CI of the topographic information EI synthesized by the method of Example 2 is indicated by a square. At the measurement point on the left, far from the topographic measurement device 4b, the method of Example 1 results in low measurement reliability CI due to the influence of the low measurement reliability CIb of the topographic measurement device 4b. However, in the method of this embodiment, the influence of the operating speed MSd is taken into consideration when determining measurement reliability CI. Therefore, at positions far from the topographic measurement device 4b, the measurement reliability CI of the topographic information EIb measured by the topographic measurement device 4b is very low, and is therefore almost ignored, resulting in a high measurement reliability CI of the synthesized topographic information SEI.

[0061] As described above, according to this embodiment, by estimating the measurement reliability CI by taking into account the measurement position and orientation reliability MSc and the motion speed MSd in addition to the measurement performance MSb and distance information DI, it becomes possible to efficiently exclude terrain information EI at points with low reliability from the synthesis process, and more accurate synthesized terrain information SEI is generated.

[0062] [Example 3] Next, a topographical information management system 500 according to a third embodiment will be described with reference to Figs. 10 to 12. The topographical information management system 500 according to the third embodiment differs from the above-described embodiments in that the server device 10 according to the third embodiment further includes a topographical information history storage unit 10e. Fig. 10 is a diagram showing the processing functions of the topographical information management system 500 according to the third embodiment. The server device 10 includes a topographical information acquisition unit 10a, a measurement point distance calculation unit 10b, a measurement reliability estimation unit 10c, a topographical information synthesis unit 10d, and a topographical information history storage unit 10e.

[0063] The topographical information history memory unit 10e links the synthesized topographical information SEI synthesized by the topographical information synthesis unit 10d with the synthesis time ST at which the synthesis was performed and the synthesized measurement reliability SCI calculated at the time of synthesis, and stores this as history information TAB for each gridded cell in the synthesis range MA.

[0064] 11 is a diagram showing an example of the history information TAB stored in the topographical information history storage unit 10e according to this embodiment. The history information TAB is generated for each gridded cell in the synthesis range MA. The history information TAB is composed of at least three pieces of information: synthesis time ST, synthesis reliability SCI, and topographical information history EH.

[0065] The synthesis time ST is the time when the terrain information EI is synthesized in the terrain information synthesis unit 10d, and is determined from the time of the server device 10 or the time of data transmission from the external measurement system 100 or the machine 200. The synthesis reliability SCI is determined from the measurement reliability CI used in the synthesis process of the terrain information EI, and in this embodiment, the maximum measurement reliability MAXCI within the same cell is taken as the synthesis reliability SCI. The terrain history EH is history information of past synthesized terrain information SEI, and in this embodiment, it is taken as height information of the terrain measured in each cell.

[0066] The history information TAB stores at least the synthesis reliability SCI and the terrain history EH at the most recent synthesis time ST, but history information from the past several times may also be stored in the same cell. Storing long-term history information makes it possible to more reliably suppress the effects of unexpected measurement errors in the synthesis process described below.

[0067] FIG. 12 is a diagram showing the processing flow executed by the terrain information history storage unit 10e of the server device 10 in this embodiment. First, in FC1b, synthesized terrain information SEI for all cells in the synthesis range MA synthesized in FC8a described in FIG. 6 is acquired. Next, in FC2b, one cell to be calculated is selected from the gridded cell group. Next, in FC3b, the history information TAB stored in the selected cell is referenced. Next, in FC4b, a process is executed to attenuate (reduce) the synthesis reliability SCI at the past synthesis time ST contained in the referenced history information TAB. The reason for attenuating the past synthesis reliability SCI in this way is because the more time has passed since the terrain was measured, the more likely it is that the terrain at the measurement point has changed since the measurement.

[0068] As described above, in the topographical information management system 500 of this embodiment, the server device 10 further includes a topographical information history storage unit 10e that stores the synthesized topographical information EI as topographical information history EH for each measurement point, linking the synthesized topographical information EI to at least the time ST at which the topographical information EI was synthesized and the synthesized measurement reliability SCI estimated from the measurement reliability CI at the time of synthesis, and the topographical information history storage unit 10e attenuates the synthesized reliability SCI of the topographical information EI stored in the topographical information history storage unit 10e based on the elapsed time from the synthesis time ST.

[0069] The attenuation process of the composite reliability SCI will be described. In this embodiment, the attenuated composite reliability SCI new is calculated so that the attenuation rate increases as the synthesis time ST becomes farther from the current time CT. As an example, in this embodiment, the calculation is performed as shown in the following equation 4.

[0070]

number

[0071] Calculated composite reliability SCI new is saved again in the history information TAB as a new composite reliability SCI, and the information is updated.

[0072] Next, in FC5b, the synthetic terrain information SEI and the terrain history EH are synthesized to generate new synthetic terrain information SEI new In this embodiment, the weighted average is calculated using the composite reliability SCI as shown in the following equation 5. That is, the topographic information history storage unit 10e combines the latest topographic information EI with past topographic information EI included in the topographic information history based on the composite reliability SCI.

[0073]

number

[0074] After the calculation of the new synthetic terrain information SEInew is completed, FC6b determines whether the calculation is complete for all cells, and if there are any cells that have not yet been calculated, the process returns to FC2b. If the calculation of all cells is completed, FC7b adds and saves the new synthetic terrain information SEInew, synthesis reliability SCInew, and synthesis time STnew for each cell in the history information TAB.

[0075] The synthesized terrain information SEI is finally outputted to the terrain information visualization unit 9a provided in the user interface 9 by the FC 9b.

[0076] As described above, in this embodiment, the synthesized topography information SEI and the topography history EH are synthesized based on the synthesis reliability SCI stored in the history information TAB. In this way, by having past topography information as history, if a specific topography measurement device 1, 4 experiences a sudden measurement failure or a drop in reliability, it is possible to minimize the impact and synthesize the topography information EI more robustly.

[0077] According to the embodiment of the present invention described above, the following advantageous effects are achieved. (1) A topographical information management system according to the present invention comprises a plurality of topographical measurement devices that measure topography and generate topographical information, and a server device that aggregates and processes the topographical information. The server device comprises a measurement point distance calculation unit that calculates the distance between the installation position of the topographical measurement device and the measurement point where the topography was measured and generates distance information, a measurement reliability estimation unit that estimates the measurement reliability of the topographical measurement device at the measurement point based on the measurement performance and distance information of each topographical measurement device, and a topographical information synthesis unit that synthesizes the topographical information generated by the plurality of topographical measurement devices based on the measurement reliability.

[0078] By adopting the above configuration, the measurement reliability of the topographical information at each measurement point is estimated based on the distance information between the installation position of each sensor and each measurement point. In addition, by taking into account the measurement reliability estimated for each sensor for each measurement point, it becomes possible to synthesize topographical information more accurately.

[0079] (2) The topographical information synthesis unit synthesizes the topographical information generated by the plurality of topographical measurement devices using a weighted average with the measurement reliability as the weight. Specifically, it is preferable that the topographical information synthesis unit uses such a calculation method.

[0080] (3) The measurement reliability estimation unit estimates measurement reliability based on the measurement position and orientation reliability in addition to measurement accuracy information and distance information. Alternatively, if a topography measurement device is installed on the work machine, the measurement reliability estimation unit estimates measurement reliability based on the measurement accuracy information and distance information as well as the operating state of the work machine. Using this information makes it possible to estimate measurement reliability more accurately.

[0081] (4) The server device further includes a topographical information history storage unit that stores the synthesized topographical information as a topographical information history for each measurement point, linking the synthesized topographical information with at least the synthesis time when the topographical information was synthesized and the synthesis measurement reliability estimated from the measurement reliability at the time of synthesis, and the topographical information history storage unit attenuates the synthesis measurement reliability of the topographical information stored in the topographical information history storage unit based on the elapsed time from the synthesis time. It is preferable to perform such processing because past topographical information that has been synthesized for a long time is likely to not reflect the correct topography.

[0082] (5) The terrain information history storage unit combines the latest terrain information with past terrain information included in the terrain information history based on the composite measurement reliability. This makes it possible to combine more accurate terrain information that also takes past terrain information into account.

[0083] (6) A server device according to the present invention aggregates and processes topography information received from multiple topography measurement devices that measure topography and generate topography information, and includes a measurement point distance calculation unit that calculates the distance between the installation position of the topography measurement device and the measurement point where the topography was measured to generate distance information, a measurement reliability estimation unit that estimates the measurement reliability of the topography measurement device for each measurement point based on the measurement accuracy information and distance information for each topography measurement device, and a topography information synthesis unit that synthesizes the topography information generated by the multiple topography measurement devices based on the measurement reliability. This configuration also provides the same effect as (1).

[0084] The present invention is not limited to the above-described embodiments, and various modifications are possible. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to embodiments including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment. It is also possible to add the configuration of another embodiment to the configuration of one embodiment. It is also possible to delete part of the configuration of each embodiment, or to add or replace other configurations. [Explanation of symbols]

[0085] 1, 4 Terrain measurement device (camera / LiDAR), 10 Server (server device), 10a Terrain information acquisition unit, 10b Measurement point distance calculation unit, 10c Measurement reliability estimation unit, 10d Terrain information synthesis unit, 10e Terrain information history storage unit, 200 Machine (work machine)

Claims

1. A method for measuring a terrain using a plurality of topographical measurement devices that measure terrain and generate topographical information, and a server device that aggregates and processes the topographical information, The server device a measurement point distance calculation unit that calculates the distance between the installation position of the topography measurement device and a measurement point where the topography is measured, and generates distance information; a measurement reliability estimation unit that estimates the measurement reliability of the topography measuring device at the measurement point based on the measurement accuracy information and the distance information for each of the topography measuring devices; a topographical information synthesis unit that synthesizes the topographical information generated by the plurality of topographical measurement devices based on the measurement reliability. A topographical information management system characterized by:

2. 2. The topographical information management system according to claim 1, the topographical information synthesis unit synthesizes the topographical information generated by the plurality of topographical measurement devices using a weighted average with the measurement reliability as a weight. A topographical information management system characterized by:

3. 2. The topographical information management system according to claim 1, the measurement reliability estimation unit estimates the measurement reliability based on the measurement accuracy information and the distance information as well as the measurement position and orientation reliability of each of the topographic measurement devices. A topographical information management system characterized by:

4. 2. The topographical information management system according to claim 1, the topographical measurement device is installed on a work machine, the measurement reliability estimation unit estimates the measurement reliability based on the measurement accuracy information and the distance information as well as an operating state of the work machine. A topographical information management system characterized by:

5. 2. The topographical information management system according to claim 1, the server device further includes a topographical information history storage unit that stores the synthesized topographical information as a topographical information history for each measurement point, in association with at least a synthesis time when the topographical information was synthesized and a synthesized measurement reliability estimated from the measurement reliability at the time of synthesis; the topographical information history storage unit attenuates the synthetic measurement reliability of the topographical information stored in the topographical information history storage unit based on the elapsed time from the synthesis time. A topographical information management system characterized by:

6. 6. The topographical information management system according to claim 5, the topographical information history storage unit combines the latest topographical information with the past topographical information included in the topographical information history based on the composite measurement reliability; A topographical information management system characterized by:

7. A server device that aggregates and processes topographical information received from a plurality of topographical measurement devices that measure topography and generate topographical information, a measurement point distance calculation unit that calculates the distance between the installation position of the topography measurement device and a measurement point where the topography is measured, and generates distance information; a measurement reliability estimation unit that estimates the measurement reliability of the topographic measuring device for each measurement point based on the measurement accuracy information and the distance information for each topographic measuring device; a topographical information synthesis unit that synthesizes the topographical information generated by the plurality of topographical measurement devices based on the measurement reliability. A server device characterized by:

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