JP7834515B2 - Scan data creation method and scan data creation system - Google Patents

Description

This disclosure relates to a method for creating scan data and a system for creating scan data.

In recent years, the adoption of modeling methods using 3D scan data, such as BIM (Building Information Modeling), has been progressing in the architectural field. BIM allows for the creation of 3D digital models of buildings and other structures on a computer, and by adding management and equipment information, it can be transformed into comprehensive architectural data, enhancing its usability for various applications. For example, it can be applied to managing the progress of construction projects.

As a measuring instrument for acquiring 3D scan data, a 3D scanner is known that irradiates laser light onto the object being measured to acquire the 3D coordinates of its surface shape. If there are any measurement omissions, the resulting 3D digital data will be incomplete.

Patent Document 1 describes a method for evaluating the placement of multiple surveillance cameras in a monitored area where obstacles exist, in order to minimize blind spots caused by the obstacles.

Japanese Patent Publication No. 2011-86995

When the object to be modeled is large or wide, the object is divided into multiple areas, 3D scan data is acquired for each area, and then the data is combined. When combining the 3D scan data acquired for each area, common objects contained in the 3D scan data of each area are used as indicators for linking.

When acquiring 3D scan data for each area and performing data synthesis in this manner, the following challenges are generally known: The appearance of the object's shape (including common objects) changes depending on the scanning angle. This leads to an accumulation of errors each time 3D scan data is synthesized using a common object as a reference. Furthermore, if the common object used as a reference cannot be recognized during data synthesis, manual synthesis becomes necessary, increasing the burden on the operator. For example, if the objects consist of a series of similar shapes, it may be difficult to recognize the common object used as a reference.

These challenges can also arise when using multiple 3D scanners to efficiently generate 3D digital models.

This disclosure was made to solve the above problems and aims to provide a scan data creation method and scan data creation system capable of synthesizing 3D scan data with high accuracy.

One aspect of the present disclosure is a scan data creation method for acquiring three-dimensional scan data synthesized using a reference sphere as an indicator in order to create a three-dimensional digital model of an object, characterized by comprising: a measurement position calculation step of calculating a plurality of measurement positions in which the object can be measured by a measuring instrument; a measurement route calculation step of calculating a measurement route that allows the measuring instrument to reach the plurality of measurement positions with the minimum movement cost; a waiting position calculation step of calculating a plurality of waiting positions in which the reference sphere can wait based on the measurement route such that the measurement range of the measuring instrument at adjacent measurement positions on the measurement route includes the reference sphere waiting at the same waiting position; a waiting route calculation step of calculating a waiting route that allows the reference sphere to reach the plurality of waiting positions based on the measurement route; and a movement order calculation step of calculating the movement order of the measuring instrument and the reference sphere such that the measurement range of the measuring instrument at adjacent measurement positions on the measurement route includes the reference sphere waiting at the same waiting position .

One aspect of the present disclosure is a scan data creation system for acquiring three-dimensional scan data synthesized using a reference sphere as an indicator in order to create a three-dimensional digital model of an object, comprising: a measuring instrument for measuring the object; a reference sphere; a command creation means; a first moving body; and a second moving body, wherein the command creation means includes: a first calculation means for calculating a plurality of measurement positions in which the object can be measured; a first calculation means for calculating a measurement route that allows the measuring instrument to reach the plurality of measurement positions with the minimum movement cost; a second calculation means for calculating a plurality of standby positions in which the reference sphere can wait, based on the measurement route, such that the measurement range of the measuring instrument at adjacent measurement positions on the measurement route includes the reference sphere waiting at the same standby position; and a second calculation means for calculating a standby route that allows the reference sphere to reach the plurality of standby positions, based on the measurement route. The system includes, a third calculation means for calculating the movement order of the measuring instrument and the reference sphere such that the measurement range of the measuring instrument at adjacent measurement positions on the measurement route includes the reference sphere waiting at the same standby position , wherein the first mobile body is capable of autonomous movement with the measuring instrument mounted on it, and moves along the measurement route in the movement order and performs measurement with the measuring instrument at the measurement position in response to a command from the command creation means, and the second mobile body is capable of autonomous movement with the reference sphere mounted on it, and moves along the standby route in the movement order and waits at the standby position in response to a command from the command creation means.

According to the scan data creation method and scan data creation system of this disclosure, 3D scan data can be synthesized with high accuracy.

This diagram shows the hardware configuration and functional blocks of the scan data creation system. This is a flowchart showing the process for creating scanned data. This diagram illustrates the determination of multiple measurement locations. This diagram shows the connection relationships that allow multiple measurement locations to be moved along the shortest distance. This diagram shows multiple measurement locations grouped together. This figure shows the measurement route with the minimum travel cost for each group. This diagram shows the order of movement along the measurement route for each group. This figure shows the results after changing the group divisions and correcting the measurement route. This is a diagram (part 1) illustrating the determination of multiple waiting positions. This is a diagram (part 2) illustrating the determination of multiple waiting positions. This diagram shows the standby routes for each group's confirmed measurement routes. This diagram shows the order of movement of a pair of moving objects. This diagram illustrates the determination of the movement order along the measurement route.

The following describes in detail the scan data creation method and scan data creation system according to the embodiment, with reference to the attached drawings. The embodiment described below is applied to acquiring 3D scan data of the internal structure of a building at a construction site.

Figure 1 is a block diagram showing the hardware configuration and functional blocks of the scan data creation system 1. The scan data creation system 1 includes a command creation unit 10, a mobile body 20, and a mobile body 40. The command creation unit 10 is an example of a command creation means that includes a first calculation means for calculating the measurement position and measurement route performed by the mobile body 20, a second calculation means for calculating the standby position and standby route where the mobile body 40 will wait, and a third calculation means for calculating the movement order of the mobile body 20 and the mobile body 40. The mobile body 20 is an example of the first mobile body. The mobile body 40 is an example of the second mobile body.

The command creation unit 10 is composed of a local server or cloud server networked with the mobile body 20, mobile body 40, and other external devices, and includes a data receiving unit 11, a data processing unit 12, and an autonomous mobile operation command unit 13. The mobile body 20 includes a computer 21 and sensors and devices comprehensively controlled by the computer 21. The mobile body 40 includes a computer 41, sensors and devices comprehensively controlled by the computer 41, and a reference sphere (also referred to as a spherical marker or spherical target) 50. In the scan data creation system 1, the mobile body 20 and mobile body 40 form a pair, and one or more pairs can be used. Each pair of mobile body 20 and mobile body 40 has the configuration shown in Figure 1.

The instruction generation unit 10 comprises, as a hardware configuration, a CPU (Central Processing Unit) as a calculation means, a ROM (Read Only Memory) as a read-only semiconductor memory, a RAM (Random Access Memory) as a random access semiconductor memory, an input device, a display device, a communication interface, and the like. The instruction generation unit 10 can communicate with external devices, including the mobile units 20 and 40, via the communication interface. The communication method can be either wired or wireless, and the communication standard is not limited.

The ROM of the instruction creation unit 10 stores various programs. The CPU of the instruction creation unit 10 reads programs from the ROM and executes them in response to operation signals from the input device. The RAM of the instruction creation unit 10 is used as a working area for programs and data when the CPU executes programs. The display device of the instruction creation unit 10 is a monitor with a display screen, which displays information such as the content and results of the processing. The functions of the data processing unit 12 in the instruction creation unit 10 are realized by at least the CPU, ROM, and RAM. Furthermore, each of the processes performed by the instruction creation unit 10, as described later, is executed based on the scan data creation program stored in the ROM.

Various data is input to the data receiving unit 11 of the command creation unit 10 through operation of the input device or communication via the communication interface. The data input to the data receiving unit 11 includes the drawing data of the building that is the measurement target (object) from which 3D scan data is to be acquired, and the number of pairs of mobile bodies 20 and 40 that are scheduled to be used (number of mobile body pairs). This data input to the data receiving unit 11 is sent to the data processing unit 12.

The data processing unit 12 calculates and determines, based on the input data, multiple measurement locations where the mobile body 20 will perform measurements, the assignment (group) of measurement locations to be handled by each mobile body 20 when multiple pairs of mobile bodies 20 and 40 are used, the measurement route which is the path the mobile body 20 will take to move between the measurement locations, multiple standby locations where the mobile body 40 will wait while the mobile body 20 is performing measurements, the standby route which is the path the mobile body 40 will take to move between the standby locations, and the movement order of the mobile body 20 and the mobile body 40. These calculation processes will be described later. The information determined by the data processing unit 12 is sent as an operation command from the autonomous movement operation command unit 13 to the mobile body 20 and the mobile body 40.

The computer 21 of the mobile unit 20 is composed of a CPU, ROM, RAM, etc. The computer 21 receives operation commands issued by the command creation unit 10 via the data receiving unit 22, and the autonomous movement command control unit 23 and the 3D scanner operation unit 24 execute the contents of the operation commands.

The mobile unit 20 is equipped with an object sensor 25, an inertial measurement device 26, and a driving unit 27. The object sensor 25 is a detector capable of measuring the distance and positional relationship with external objects. For example, a ToF (Time of Flight) type sensor using LiDAR (Light Detection And Ranging) technology or a stereo camera capable of capturing stereo images can be applied as the object sensor 25. The inertial measurement device 26 is also called an IMU (Internal Measurement Unit) and has sensors that detect various motion information such as acceleration and rotational angular velocity. Alternatively, a 360-degree camera can be used instead of the object sensor 25. By using a 360-degree camera, surrounding objects can be detected in a single shot. The drive unit 27 is a drive system mechanism consisting of wheels and tracks that make contact with the ground, motors and power transmission systems for operating the wheels and tracks. By obtaining information about surrounding objects and obstacles via the object sensor 25, recognizing the attitude and movement state of the vehicle using the inertial measurement device 26, and applying driving force via the drive unit 27, the mobile vehicle 20 can autonomously move to the measurement position without human intervention.

The mobile unit 20 is further equipped with a measuring instrument, a 3D scanner 30. The 3D scanner 30 is a non-contact optical scanner. The measuring unit 31 irradiates an object with a light beam, such as a laser beam, and analyzes the time difference of reflection and the irradiation angle to acquire the object's 3D shape. The 3D scanner 30 in this embodiment is a type that irradiates laser light radially from the measuring unit 31, enabling omnidirectional measurement. The 3D scan data acquired by the measuring unit 31 is stored in the data storage unit 32.

The 3D scan data stored in the data storage unit 32 of the mobile unit 20 is sent to the server or other data processing device that constitutes the command creation unit 10. By combining (concatenating) the 3D scan data acquired by each mobile unit 20 at multiple measurement locations, 3D scan data representing the entire building, which is the object of measurement, can be created. By having each mobile unit 20 acquire 3D scan data so that it includes a common object, the reference sphere 50, at adjacent measurement locations, data synthesis can be performed with high accuracy using the reference sphere 50 as an indicator.

The computer 41 of the mobile unit 40 is composed of a CPU, ROM, RAM, etc. The computer 41 receives operation commands issued by the instruction creation unit 10 via the data receiving unit 42, and the autonomous movement command control unit 43 executes the contents of the operation commands.

The mobile unit 40 is equipped with an object sensor 44, an inertial measuring device 45, and a driving unit 46. These are the same as those found in the object sensor 25, inertial measuring device 26, and driving unit 27 of the mobile unit 20. By obtaining information about surrounding objects and obstacles via the object sensor 44, recognizing its own attitude and movement state via the inertial measuring device 45, and applying driving force via the driving unit 46, the mobile unit 40 can autonomously move to its standby position without driver intervention.

The mobile unit 40 is further equipped with a reference sphere 50. The reference sphere 50 serves as an indicator when synthesizing 3D scan data acquired at adjacent measurement positions. Because the reference sphere 50 is spherical, its appearance does not change even if the scanning angle differs. Therefore, it is suitable as an indicator when synthesizing 3D scan data and is effective in improving the synthesis accuracy.

As described above, the 3D scan data created using the scan data creation system 1 is used for creating 3D digital models of buildings, etc.

Next, referring to the flowchart in Figure 2 and the explanatory diagrams from Figure 3 onward, we will explain in detail how the command generation unit 10 determines the measurement position and measurement route, the standby position and standby route, and the movement order of the mobile units 20 and 40.

The explanatory diagrams from Figure 3 onward show the case where the internal structure of a building 60 is scanned as the target object. The building 60 has a box-shaped outer wall 61 and multiple partition walls 62 located within the space enclosed by the outer wall 61. For the sake of clarity, Figures 3 through 12 show the building 60 in a plan view; however, the acquired 3D scan data will also include information in the height direction (the direction perpendicular to the plane of the paper in Figures 3 through 12).

[Step S1: Data Entry Step]
In step S1, data from the drawing (design drawing) of the building 60 to be measured is input to the data receiving unit 11 of the command creation unit 10, and the input drawing data, along with coordinate information, is expanded into the work area of the data processing unit 12. In addition, the number of pairs of mobile bodies 20 and 40 used for measurement (number of mobile body pairs) is input to the data receiving unit 11 and is held in the work area of the data processing unit 12 as mobile body pair number data. This embodiment illustrates the case where two pairs of mobile bodies 20 and 40 are used, and mobile body pair number data indicating two pairs is input.

[Step S2: Measurement position calculation step]
Step S2 is processed by the measurement position calculation unit 12a (Figure 1), which is a functional block of the data processing unit 12. In step S2, the data processing unit 12 of the command creation unit 10 calculates the measurement positions where the mobile body 20 will acquire 3D scan data. When calculating the measurement positions, the following conditions are imposed: the entire object to be measured should be scanned to minimize blind spots; the number of measurement positions should be kept to a minimum; and the scanning ranges of adjacent measurement positions should include overlapping areas. Multiple measurement positions that satisfy these conditions are determined. The overlapping areas may include the reference sphere 50, which will serve as an indicator for later data synthesis. Each measurement position determined in step S2 is stored as coordinate data in the RAM of the command creation unit 10.

In step S2, the measurement position can be calculated using the position evaluation method described in Japanese Patent Publication No. 2011-86995 (Patent Document 1). Briefly, a non-diffraction Voronoi diagram is created for the measurement target area, where the blind spots of obstacles viewed from each generator point are considered non-diffraction areas. The measurement positions within the measurement target area are then evaluated using this non-diffraction Voronoi diagram.

Figure 3 shows the results of the processing performed in step S2 for building 60. As a result of the calculation, 12 measurement positions were determined, from measurement position P1 to measurement position P12. Measurements are performed at each of these measurement positions P1 to P12 using the 3D scanner 30. If there are partition walls 62, the laser beam from the measurement unit 31 is directed from both sides of the partition wall 62 to scan the entire internal structure of building 60 and obtain 3D scan data.

[Step S3: Movable Information Calculation Step]
Step S3 is processed by the movable information calculation unit 12b (Figure 1), which is a functional block of the data processing unit 12. In step S3, movable information between multiple measurement positions is calculated. In this calculation process, provisional connection relationships (links) are set between the multiple measurement positions obtained in step S2 that can be moved along the shortest distance (straight-line movement) without being obstructed by obstacles such as partition walls 62. For example, a straight line is set to connect each of the multiple measurement positions, and it is determined whether or not there are obstacles that obstruct each straight line in the drawing data. Then, a straight line without obstacles is established as a link. In this way, a graph is created in which the measurement positions are vertices or nodes and the links are edges. The link information created in step S3 is stored in the RAM of the command creation unit 10.

Figure 4 shows the results of the processing in step S3 for building 60. All measurement points P1 to P12 are connected to other measurement points by at least one link L. In Figure 4, only the link L connecting measurement point P2 and measurement point P5 is labeled, but all solid lines connecting each measurement point represent links L. On the other hand, dashed lines indicate that the points are blocked by partitions 62 or other barriers, meaning that movement is not possible via the shortest distance, and therefore a link is not formed.

Figure 4 shows examples of locations where a link cannot be formed due to the partition wall 62, specifically between measurement position P1 and P2, between measurement position P3 and P6, between measurement position P9 and P10, and between measurement position P11 and P12. These are not the only locations where a link cannot be formed; there are several other locations. For example, a link cannot be formed between measurement position P1 and measurement position P3 because a bend in the outer wall 61 lies on the straight line connecting them.

[Step S4: Measurement Location Classification Step]
Step S4 is processed by the measurement position assignment calculation unit 12c (Figure 1), which is a functional block of the data processing unit 12. In step S4, a calculation is performed to group (classify) multiple measurement positions. Based on the number of mobile object pairs data input to the data receiving unit 11, groups are created for each number of mobile object pairs, and the measurement positions to be included in each group are determined. Specifically, starting from any measurement position on the graph based on the number of mobile object pairs, adjacent measurement positions connected by links are added to the same group one by one. It is efficient to start from different ends for the first measurement position. This process is performed for each group, and the process stops when all measurement positions are included in a group. Since all measurement positions belong to one of the groups, the grouping is completed.

It is preferable that the number of measurement positions in each group be nearly equal, but in the processing in step S4, the number of measurement positions in each group may not be equal. Furthermore, if the total number of measurement positions is not divisible by the number of groups (number of moving object pairs), the number of measurement positions in each group will inevitably be unequal. In either case, the correction process described later optimizes the number of measurement positions in each group, taking into account the movement cost.

Figure 5 shows the results of the processing performed in step S4 for building 60. Based on the two input data points for the number of moving object pairs, the measurement positions P1 to P12 are divided into two groups: Group 1 and Group 2. In the initial grouping shown in Figure 5, the five measurement positions P1 to P5 are included in Group 1, and the seven measurement positions P6 to P12 are included in Group 2.

[Step S5: Measurement Route Calculation Step]
Step S5 is processed by the measurement route calculation unit 12d (Figure 1), which is a functional block of the data processing unit 12. In step S5, the measurement route for each group, that is, the movement path of each pair of mobile bodies 20, is determined. The determination of the measurement route is performed using the criterion of which of the previously set links is the most efficient route (the one with the lowest movement cost), and includes the following two substeps. Movement cost is either the distance traveled or the time spent traveling. In this embodiment, the movement speed of the mobile bodies 20 is assumed to be constant.

[Step S5, first substep]
In the first substep of step S5, a minimum spanning tree in graph theory is found based on a graph in which the measurement locations of each group are vertices or nodes and links are edges. A spanning tree is a tree obtained by eliminating edges while maintaining the condition that the graph is connected, and a minimum spanning tree is a spanning tree in which the sum of the costs of each edge is minimized. For example, Kruskal's algorithm can be used as an algorithm to find the minimum spanning tree.

Figure 6 shows the results of the processing of the first substep in step S5 for building 60. In Figure 6, link L1, represented by a solid line, constitutes the minimum spanning tree, and this portion is the measurement route. Link L2, represented by a dashed-dotted line in Figure 6, is a portion that does not correspond to the minimum spanning tree. In Figure 6, only one symbol is assigned to each link L1 and L2; however, all solid lines connecting each measurement position represent link L1, and all dashed-dotted lines represent link L2.

In the first group, the sum of the costs of each edge in the spanning tree is minimized when measurement point P4 is used as the hub (center), and measurement points P1, P2, P3, and P5 are connected radially to it.

In the second group, the sum of the costs of each edge in the spanning tree is minimized when measurement point P7 is used as the hub (center), connecting to measurement points P6, P8, and P10, then connecting from measurement point P6 to measurement points P9 and P11, and finally connecting from measurement point P10 to measurement point P12.

[Second substep of Step S5]
In the second substep of step S5, the order in which to move between the edges of the previously defined minimum spanning tree is determined, and the order with the lowest movement cost is selected. The determination of the movement order is based on a depth-first search algorithm, starting from the measurement position located at any of the terminals (vertices) in the group.

Figure 13 shows example routes A through F for the movement sequence of measurement locations in the second group. These route examples A through F compare the movement costs when starting from measurement locations P8, P11, and P12, which are at the end of the second group (connected by only one other measurement location via a link). Since there is one branching point in each case, there are a total of six route examples, including the cases where each branch is reached.

The basic idea is that the travel cost is minimized when all edges included in a route can be traversed in a single continuous line (without backtracking). Assuming that each edge has the same length (distance), the travel cost increases as the number of edges requiring backtracking, or the number of backtracking trips along a particular edge, increases. For example, when traveling from a branch to the terminal node (measurement point) and then returning along the same route back to the original branch, backtracking occurs along the edges included in that round trip. In the route examples A-F in Figure 13, the change in the numbers following the letters A-F indicates a change in direction due to a choice at a branch or a backtracking trip.

In the example route A in Figure 13, the starting point is measurement position P11, the path proceeds to measurement position P7 (A1), then branches off towards measurement position P8 (A2), and returns from measurement position P8 to measurement position P7 (A3). This A2 and A3 movement constitutes a round trip. Next, the path proceeds towards measurement position P10, an unexplored node, and ends at measurement position P12 (A4). In this case, the number of edges to return is "1".

In Route Example B in Figure 13, the route is the same as Route Example A up to the point where it starts at measurement position P11 and proceeds to measurement position P7 (B1). At the branching point, it proceeds towards measurement position P10 and reaches the terminal measurement position P12 (B2), then returns to measurement position P7 (B3). This B2 and B3 movement constitutes a round trip. Next, it proceeds towards the unexplored node, measurement position P8, which is the endpoint (B4). In this case, the number of edges to return is "2".

In the example route C in Figure 13, the starting point is measurement position P8, and the path proceeds to measurement position P7 (C1). At the branching point, the path proceeds towards measurement position P6, reaching the terminal measurement position P11 (C2), and then returns to measurement position P7 (C3). This C2 and C3 movement constitutes a round trip. Next, the path proceeds towards the unexplored node, measurement position P10, and ends at the terminal measurement position P12 (C4). In this case, the number of edges to return is "3".

In Route Example D in Figure 13, the route is the same as Route Example C up to the point where it starts at measurement position P8 and proceeds to measurement position P7 (D1). At the branching point, it proceeds towards measurement position P10 and reaches the terminal measurement position P12 (D2), then returns to measurement position P7 (D3). This D2 and D3 represent a round trip movement. Next, it proceeds towards the unexplored node, measurement position P6, and ends at the terminal measurement position P11 (D4). In this case, the number of edges to return is "2".

In the example route E in Figure 13, the starting point is measurement position P12, and the path proceeds to measurement position P7 (E1). At the branching point, the path proceeds towards measurement position P6, reaching the terminal measurement position P11 (E2), and then returns to measurement position P7 (E3). This E2 and E3 movement constitutes a round trip. Next, the path proceeds towards measurement position P8, an unexplored node, to reach the endpoint (E4). In this case, the number of edges to return is "3".

In example route F in Figure 13, the route is the same as example route E up to the point where it starts at measurement position P12 and proceeds to measurement position P7 (F1). At the branch, it proceeds towards measurement position P8 (F2), and then returns from measurement position P8 to measurement position P7 (F3). This F2 and F3 movement constitutes a round trip. Next, it proceeds towards measurement position P6, an unexplored node, and ends at the terminal measurement position P11 (F4). In this case, the number of edges to return is "1".

As can be seen from the route examples A to F above, the number of return edges may differ depending on the order in which the multiple measurement locations are moved in the measurement route determined in the second substep of step S5. Route examples A and F, which have the fewest return edges, have the shortest total travel distance and can be completed in the shortest time, thus representing the order of movement with the minimum travel cost.

Route example G shown in Figure 13 is a comparative example of setting a route using the breadth-first search method. Starting from measurement position P7, the route proceeds to measurement positions P6, P9, and P11 (G1). At measurement position P11, it turns back and returns to measurement position P7 (G2). Next, it proceeds towards measurement position P10 among the unexplored nodes to reach the terminal measurement position P12 (G3). At measurement position P12, it turns back and returns to measurement position P7 (G4). Furthermore, it proceeds towards measurement position P8, which is an unexplored node, to reach the endpoint (G5). In this case, the number of edges to return to is "5".

Route example G shows the case with the largest number of return edges. However, in route setting using breadth-first search starting from measurement position P7, the number of return edges will be at least 3. Therefore, it can be seen that depth-first search is more suitable than breadth-first search for calculating the minimum movement cost.

Note that while Figure 13 focuses on the number of edges to return to, if the cost (distance) of each edge is not uniform, it is necessary to calculate the movement cost including the differences in the costs of the individual edges that cause the return. For example, even if the number of edges to return is the same, if the cost (length) of the edges to return differs, the sequence with the smaller cost of the edges to return should be selected as the movement sequence with the minimum movement cost.

Furthermore, even if the number of edges to return to is "1," if the cost of that single edge is large, and the return travel distance (amount of movement) is greater than if you were to return to two other edges, then returning to the other two edges will result in a lower overall travel cost for the group. Therefore, it is best to store the cost of each edge in the minimum spanning tree determined in the first substep of step S5, and then in the second substep of step S5, determine the route that minimizes the sum of the costs of the edges that result in a return as the route with the minimum travel cost.

Figure 13 illustrates the second group, but the second substep in step S5 is performed similarly for the first group to determine the measurement route with the minimum travel cost.

As described above, a measurement route is determined for each group to allow the mobile unit 20 to reach multiple measurement locations with the minimum movement cost. Figure 7 shows the results of the processing of the second substep in step S5 for the building 60. The arrows next to the edges (links) connecting each measurement location in Figure 7 indicate whether or not a return trip occurs along the determined measurement route. Where there are two arrows, one in forward and one in opposite directions, on both sides of an edge, it means that a return trip occurs from the measurement location at the end to the branch. Where there is a one-way arrow on only one side of an edge, it means that the route is a single continuous path without any return trips.

In the example shown in Figure 7, the first group has its measurement route movement sequence set starting from measurement position P1. In the first group, since the edges connecting each measurement position P1 to P3 and P5 are spoke-like around measurement position P4, the measurement route results in a return movement occurring at all edges except the edge from the starting point (measurement position P1) to measurement position P4.

In the example shown in Figure 7, the second group adopts Route Example A, explained with reference to Figure 13, as the order of movement for the measurement route. This measurement route involves a return movement between measurement position P7 and measurement position P8, but no return movement occurs on any of the other edges.

[Step S6, Step S7: Measurement route evaluation step]
Step S6 is processed by the calculation result evaluation unit 12e (Figure 1), which is a functional block of the data processing unit 12. In step S6, the measurement route calculated in step S5 is evaluated. In this evaluation, the travel costs of the measurement routes for each group are compared. The lower the travel cost for each group, the shorter the time required for scanning in that group. Also, when scanning is performed in parallel with multiple groups, the smaller the variation in travel costs between the multiple groups, the shorter the time required to complete the overall scanning work. From this perspective, the measurement route in which the travel costs of each group are most evenly distributed is the best in terms of work efficiency and work time, and whether or not this best measurement route is selected is the evaluation criterion. If it is not the best measurement route, it is determined that there is "room for improvement," and the result is YES in step S7, and the process proceeds to step S8. If it is the best measurement route, it is determined that "no improvement is needed," and the result is NO in step S7, and the process proceeds to step S9.

[Step S8: Measurement Route Correction Step]
Step S8 is processed by the calculation result correction unit 12f (Figure 1), which is a functional block of the data processing unit 12. In step S8, the grouping of measurement locations is changed. Specifically, from the grouping done in step S4, the affiliation of one measurement location is temporarily changed to another group. Returning from step S8 to step S4, step S5 calculates the measurement route that minimizes travel cost for each updated group. Then, the evaluation in step S6 is performed again.

In other words, after changing the group to which a single measurement location belongs (steps S8 and S4), the minimum travel cost is recalculated for each group (step S5), and it is evaluated whether an improvement in travel cost is expected compared to the previous calculation result (step S6). As for the evaluation method, for example, one can choose to aim to minimize the travel cost in the group with the highest travel cost among all groups (making the maximum travel cost as small as possible), or to minimize the difference in travel costs between the group with the highest and lowest travel costs (making the difference in travel costs as small as possible).

The loop from step S8 back to step S4 and continuing until the judgment result of step S7 is obtained is a correction process for the calculation results related to the measurement route. Therefore, strictly speaking, the measurement route correction step includes not only step S8, but also steps S4 through S7 from the second time onward. The change history of group divisions and the calculation results of movement costs performed during the correction process are stored in the RAM of the instruction creation unit 10. The correction process for the calculation results is then repeated until the judgment in step S7 becomes NO (no further improvement is possible).

An example of the correction process for the calculation results is shown in Figure 8. In Figure 8, the measurement position P8 is changed from the second group to the first group (step S8), and the contents of the first and second groups are updated (step S4). For the updated first and second groups, the measurement route is calculated (step S5), and the calculation results are evaluated (step S6). At this time, the route that most evenly distributes the travel costs between the first and second groups is extracted as the measurement route, and the travel costs are determined.

In Figure 7, before correction, the first group has 4 edges and the second group has 6 edges. In contrast, in Figure 8, after correction, both the first and second groups have 5 edges. Therefore, the movement cost of the second group, which was high in Figure 7, has decreased, and the difference in movement costs between the two groups has also decreased. Thus, the measurement route in Figure 8 is an improvement over the measurement route in Figure 7.

Furthermore, in the pre-correction state shown in Figure 7, the first group includes five measurement locations (P1-P5), and the second group includes seven measurement locations (P6-P12). In contrast, in the post-correction state shown in Figure 8, both the first and second groups include six measurement locations, thus averaging the scanning time across each group. This averaging of the number of measurement locations across groups may be included as a criterion for determining improvement.

Furthermore, considering the return movement, the following can be observed. In the corrected version shown in Figure 8, since measurement position P8 is no longer in the second group, the second group becomes a route without any branches. Regardless of whether measurement position P11 or P12 is the starting point, this represents the minimum movement cost without requiring a return movement. Therefore, for the second group, the reduction in movement cost due to the group classification update is reliably obtained.

In addition to measurement location P8, where the group affiliation was changed in Figure 8, the same calculation and evaluation of the measurement route when the group is changed will be performed for all measurement locations that can be changed to a different group. A measurement location that can be changed to a different group is one that satisfies the following conditions: "it is connected by links to two or more other measurement locations" and "the change in group affiliation does not increase the number of groups (it does not disrupt the link structure of each existing group)."

For example, in the initial grouping shown in Figure 5, measurement positions P1, P2, P4, P5, P7, and P8 are measurement positions that can be moved to another group. Measurement positions P6, P9, and P10 cannot be moved to another group if they change their affiliation from the second group to the first group, as the end measurement positions P11 and P12 become a new group separated from the second group. Measurement positions P3, P11, and P12 have only one link destination, and it is not possible to skip that link destination and connect to measurement positions in other grooves; therefore, they cannot be moved to another group.

As shown in Figure 8, once the minimum movement cost for each group has been calculated when measurement position P8 is changed to the first group, measurement position P8 is returned to the second group. Next, the minimum movement cost for each group when measurement position P7 is changed from the second group to the first group is calculated, and measurement position P7 is returned to the second group. Similarly, the minimum movement cost for each group when measurement positions P1, P2, P4, and P5 are changed from the first group to the second group is calculated. In this way, each measurement position that can be changed to another group is changed one by one, and the minimum movement cost for each group in each case is calculated.

If the travel cost calculated after changing the measurement location group is better than the existing best travel cost stored (for example, if the travel cost of the group with the highest travel cost has decreased, or if the difference in travel costs between the group with the highest and lowest travel costs has narrowed), the improved travel cost is updated and stored. If the existing best travel cost stored is better than the travel cost calculated after changing the measurement location group, the existing travel cost is retained.

In this way, the measurement position grouping and movement cost calculation are repeated, and the calculation results are corrected. Finally, the grouping of measurement positions and the measurement route for each group are finalized, resulting in the optimal movement cost (the state where the determination in step S7 is "NO"). This finalized content becomes the final measurement route that allows each moving object 20 to reach multiple measurement positions P1 to P12 with the minimum movement cost, and the information of the finalized measurement route is stored in the RAM of the instruction creation unit 10.

In the following explanation, we will assume that the confirmed data is divided into two groups, as shown in Figure 8: measurement positions P1-P5 and P8 belong to the first group, and measurement positions P6, P7, and P9-P12 belong to the second group. The confirmed measurement route for the first group is P2→P4→P5→P4→P8→P4→P3→P4→P1, and the confirmed measurement route for the second group is P11→P9→P6→P7→P10→P12.

[Step S9: Standby position calculation step]
Step S9 is processed by the standby position calculation unit 12g (Figure 1), which is a functional block of the data processing unit 12. In step S9, the data processing unit 12 of the instruction creation unit 10 calculates the standby positions in which the mobile body 40 will wait while the mobile body 20 is measuring, for each group's determined measurement route. The calculation of standby positions is performed, in principle, under the condition that the same standby position (more specifically, the reference sphere 50 of the mobile body 40 waiting at the same standby position) is included in the scan range (measurement range) of adjacent measurement positions on the determined measurement route, and multiple standby positions are determined. Each standby position determined in step S9 is stored as coordinate data in the RAM of the instruction creation unit 10. The calculation of standby positions includes, for example, the following two substeps.

[First substep of Step S9]
In the first substep of step S9, three adjacent consecutive measurement locations on the determined measurement route for each group are connected by straight lines to create a triangle.

Figure 9 shows the results of the processing performed in the first substep of step S9 for building 60. In Figure 9, in the first group, triangle T1 is created by connecting three adjacent consecutive measurement positions P2, P4, and P5 with straight lines; triangle T2 is created by connecting three adjacent consecutive measurement positions P5, P4, and P8 with straight lines; triangle T3 is created by connecting three adjacent consecutive measurement positions P8, P4, and P3 with straight lines; and triangle T4 is created by connecting three adjacent consecutive measurement positions P3, P4, and P1 with straight lines. In the second group, triangles T5 was created by connecting three adjacent measurement points P11, P9, and P6 with straight lines; triangle T6 was created by connecting three adjacent measurement points P9, P6, and P7 with straight lines; triangle T7 was created by connecting three adjacent measurement points P6, P7, and P10 with straight lines; and triangle T8 was created by connecting three adjacent measurement points P7, P10, and P12 with straight lines.

[Second substep of Step S9]
In the second substep of step S9, the centroid position of each triangle created in the first substep of step S9 is calculated as a standby position. However, if the centroid position is in a position where the mobile body 40 cannot stand, such as when it overlaps with the outer wall 61 or the bulkhead 62, that centroid position is excluded and not considered a standby position. Also, if multiple centroid positions are close together (for example, within 1 m), only one of those multiple centroid positions is considered a standby position, and the rest are excluded and not considered standby positions.

Figure 10 shows the results of the processing performed in the second substep of step S9 for building 60. In Figure 10, for the first group of confirmed measurement routes, the centroid positions H1 of triangle T1, H2 of triangle T2, and H3 of triangle T3 are calculated as standby positions. Note that the centroid position H4 of triangle T4 is excluded as it overlaps with the outer wall 61 and is therefore not considered a standby position. For the second group of confirmed measurement routes, the centroid positions H5 of triangle T5, H7 of triangle T7, and H8 of triangle T8 are calculated as standby positions. Note that since the centroid positions H6 of triangle T6 and H7 of triangle T7 are close together, only centroid position H7 is designated as a standby position, and the remaining centroid position H6 is excluded.

[Step S10: Waiting route calculation step]
Step S10 is processed by the standby route calculation unit 12h (Figure 1), which is a functional block of the data processing unit 12. In step S10, the standby route for each group relative to the confirmed measurement route, that is, the movement path of each pair of mobile bodies 40, is determined. The standby route is determined by connecting each standby position with a straight line so that it becomes a single-stroke route, based on the confirmed measurement route (the order of movement of each measurement position by the mobile body 20). However, if the route between standby positions is blocked by the outer wall 61 or the partition wall 62, the route between those standby positions is replaced with a route that uses a part of the confirmed measurement route. The standby route determined in step S10 is stored in the RAM of the instruction creation unit 10.

Figure 11 shows the results of the processing in step S10 for building 60. In Figure 11, the standby route from standby position H1 → H2 → H3 is determined for the first group's confirmed measurement route. For the second group's confirmed measurement route, the standby route from standby position H5 → measurement position P9 → P6 → standby position H7 → measurement position P7 → standby position H8 is determined. Note that for the second group's confirmed measurement route, the route connecting standby positions H5 and H7 in a straight line is blocked by the partition wall 62. Therefore, the route between these standby positions (H5 → H7) is replaced with a route using a portion of the confirmed measurement route (H5 → P9 → P6 → H7). Similarly, the route connecting standby positions H7 and H8 in a straight line is also blocked by the partition wall 62. Therefore, the route between these standby positions (H7 → H8) is replaced with a route using a portion of the confirmed measurement route (H7 → P7 → H8).

[Step S11: Movement Order Calculation Step]
Step S11 is processed by the movement order calculation unit 12i (Figure 1), which is a functional block of the data processing unit 12. In step S11, the movement order of each pair of moving bodies 20 and 40 is determined. The determination of the movement order is, in principle, performed under the condition that the same standby position (more specifically, the reference sphere 50 of the moving body 40 waiting at the same standby position) is included in the scan range (measurement range) of adjacent measurement positions on the fixed measurement route. The determined movement order is stored in the RAM of the instruction creation unit 10.

Figure 12 shows the results of the processing in step S11 for the building 60. In Figure 12, the movement sequence of a pair of mobile bodies 20 and 40 is determined as follows: First, mobile body 40 moves to standby position H1. Next, mobile body 20 moves sequentially to measurement positions P2, P4, and P5 (I1, I2). Next, mobile body 40 moves from standby position H1 to standby position H2 (I3). Next, mobile body 20 moves sequentially from measurement position P5 to measurement positions P4 and P8 (I4, I5). Next, mobile body 40 moves from standby position H2 to standby position H3 (I6). Next, mobile body 20 moves sequentially from measurement position P8 to measurement positions P4, P3, P4, and P1 (I7 to I10). In this sequence of movement between the mobile body 20 and mobile body 40, for example, while mobile body 40 is waiting at standby position H1, measurements are taken by mobile body 20 at measurement positions P2, P4, and P5; while mobile body 40 is waiting at standby position H2, measurements are taken by mobile body 20 at measurement positions P4 and P8; and while mobile body 40 is waiting at standby position H3, measurements are taken by mobile body 20 at measurement positions P4, P3, and P1.

In Figure 12, the movement sequence of another pair of mobile bodies 20 and 40 is determined as follows: First, mobile body 40 moves to standby position H5. Next, mobile body 20 moves sequentially to measurement positions P11 and P9 (J1). Next, mobile body 40 moves from standby position H5 to standby position H7 via measurement positions P9 and P6 (J2-J4). Next, mobile body 20 moves sequentially from measurement position P9 to measurement positions P6 and P7 (J5, J6). Next, mobile body 40 moves from standby position H7 to standby position H8 via measurement position P7 (J7, J8). Next, mobile body 20 moves sequentially from measurement position P7 to measurement positions P10 and P12 (J9, J10). In this sequence of movement between the mobile body 20 and mobile body 40, for example, while mobile body 40 is waiting at standby position H5, measurements are taken by mobile body 20 at measurement positions P11 and P9; while mobile body 40 is waiting at standby position H7, measurements are taken by mobile body 20 at measurement positions P6 and P7; and while mobile body 40 is waiting at standby position H8, measurements are taken by mobile body 20 at measurement positions P10 and P12.

[Step S12: Step to issue commands to the mobile unit]
In step S12, based on the movement order of each pair of mobile bodies 20 and 40 calculated by the data processing unit 12, the autonomous movement operation command unit 13 transmits operation commands to each pair of mobile bodies 20 and 40.

For example, if the movement order is determined as shown in Figure 12, the following commands are sent to a pair of moving objects 20 and 40. First, moving object 40 is sent the command "Move to standby position H1". Next, moving object 20 is sent the command "Move to measurement positions P2, P4, and P5 in order, and perform a scan with the 3D scanner 30 at each measurement position". Next, moving object 40 is sent the command "Move to standby position H2". Next, moving object 20 is sent the command "Move to measurement positions P4 and P8 in order, and perform a scan with the 3D scanner 30 at each measurement position". Next, moving object 40 is sent the command "Move to standby position H3". Next, moving object 20 is sent the command "Move to measurement positions P4, P3, P4, and P1 in order, and perform a scan with the 3D scanner 30 at each measurement position".

The following commands are sent to another pair of mobile units 20 and 40. First, mobile unit 40 is sent the command "Move to standby position H5". Next, mobile unit 20 is sent the command "Move sequentially to measurement positions P11 and P9, and perform a scan with the 3D scanner 30 at each measurement position". Next, mobile unit 40 is sent the command "Move to standby position H7 via measurement positions P9 and P6". Next, mobile unit 20 is sent the command "Move sequentially to measurement positions P6 and P7, and perform a scan with the 3D scanner 30 at each measurement position". Next, mobile unit 40 is sent the command "Move to standby position H8 via measurement position P7". Next, mobile unit 20 is sent the command "Move sequentially to measurement positions P10 and P12, and perform a scan with the 3D scanner 30 at each measurement position".

Furthermore, the timing for sending a command to one of the paired mobile units 20 and 40, after sending a command to the other, may be after receiving notification of the completion of command execution from the other unit, or, if the time required for command execution on the other unit can be predicted, it may be after that predicted time has elapsed.

The transmission of the command in step S12 completes the series of processes in the command creation unit 10, and the system exits the flowchart in Figure 2. Note that in the functional blocks of the data processing unit 12 that process each of the steps described above, the measurement position calculation unit 12a, the movable information calculation unit 12b, the measurement position assignment calculation unit 12c, the measurement route calculation unit 12d, the calculation result evaluation unit 12e, and the calculation result correction unit 12f are examples of the first calculation means. The standby position calculation unit 12g and the standby route calculation unit 12h are examples of the second calculation means. The movement sequence calculation unit 12i is an example of the third calculation means.

Each mobile unit 20 receives commands from the command creation unit 10 via the data receiving unit 22. The autonomous movement command control unit 23 operates the driving unit 27 while referring to signals from the object sensor 25 and the inertial measurement device 26 to execute movement to each measurement position specified by the command. Upon reaching each measurement position, the mobile unit 20 stops moving, and the 3D scanner operation unit 24 controls the 3D scanner 30 to perform a scan of the target object.

Each mobile unit 40 receives commands from the command creation unit 10 via the data receiving unit 42. The autonomous movement command control unit 43 operates the driving unit 46 while referring to signals from the object sensor 44 and the inertial measuring device 45 to execute movement to the standby position specified by the command. When the mobile unit 40 reaches the standby position, it stops moving. If a mobile unit 20 is stopped at a measurement position when the mobile unit 40 moves to the standby position via a measurement position, in order to avoid a collision with the mobile unit 20, the mobile unit 40 considers that it has reached the measurement position when the distance between the mobile unit 40 and the mobile unit 20 measured by the object sensor 44 reaches within a predetermined distance (for example, within 1 m), and then proceeds to the standby position. For example, in the standby route for the second group's confirmed measurement route, when the mobile body 40 moves from standby position H5 to standby position H7, measurement position P9 is passed through which the mobile body 20 is stopped. In this case, when the distance between the mobile body 20 stopped at measurement position P9 and the mobile body 40 reaches within a predetermined distance, it is considered that the mobile body has reached measurement position P9, and the subsequent movement to standby position H7 is performed.

The data processing unit 12 of the command creation unit 10 determines the measurement route in a way that minimizes the difference in movement costs between groups of moving objects 20, and reduces the movement cost of the moving object 20 in the group with the highest movement cost. Therefore, when acquiring 3D scan data by simultaneously operating multiple pairs of moving objects 20 and 40, the time required to complete all measurement work can be shortened. As a result, 3D scan data can be created efficiently. Furthermore, since the scan range of two adjacent measurement positions on the determined measurement route of each group generally includes a common object, the reference sphere 50, can be used as an indicator to synthesize the 3D scan data, improving the synthesis accuracy. Even with objects that have a series of similar shapes, the reference sphere 50 can be used as an indicator, eliminating the need for manual synthesis work due to the inability to recognize a common object.

As an example, we have explained the case where there are two pairs of mobile bodies 20 and 40, but this method can also be applied when using three or more pairs of mobile bodies 20 and 40. Processing is possible by changing the number of groups set in step S4 according to the number of pairs of mobile bodies 20 and 40.

As explained above, the scan data creation method and scan data creation system of this disclosure make it possible to synthesize 3D scan data with high accuracy.

Furthermore, the present invention is not limited to the embodiments described above, and can be appropriately modified and implemented without altering its essence.

For example, in the above embodiment, in step S12, commands were transmitted alternately multiple times to each pair of mobile bodies 20 and 40. However, if the time it takes for mobile body 20 to move to the starting measurement position, the time it takes for mobile body 20 to move between each measurement position, the measurement time at each measurement position by mobile body 20, the time it takes for mobile body 40 to move to the starting standby position, and the time it takes for mobile body 40 to move between each standby position are known in advance, then commands may be transmitted only once to each pair of mobile bodies 20 and 40. In this case, for example, in one pair, the mobile unit 40 receives the command "move to standby position H1 and wait for a predetermined time, then move to standby position H2 and wait for a predetermined time, then move to standby position H3," and the mobile unit 20 receives the command "after a predetermined time has elapsed, move sequentially to measurement positions P2, P4, and P5 and perform a scan with the 3D scanner 30 at each measurement position, then after a predetermined time has elapsed, move sequentially to measurement positions P4 and P8 and perform a scan with the 3D scanner 30 at each measurement position, then after a predetermined time has elapsed, move sequentially to measurement positions P4, P3, P4, and P1 and perform a scan with the 3D scanner 30 at each measurement position."

In another pair, the mobile unit 40 receives the command to "move to standby position H5 and wait for a predetermined time, then move to standby position H7 via measurement positions P9 and P6 in order and wait for a predetermined time, then move to standby position H8 via measurement position P7," and the mobile unit 20 receives the command to "move to measurement positions P11 and P9 in order after a predetermined time has elapsed and perform a scan with the 3D scanner 30 at each measurement position, then move to measurement positions P6 and P7 in order after a predetermined time has elapsed and perform a scan with the 3D scanner 30 at each measurement position, then move to measurement positions P10 and P12 in order after a predetermined time has elapsed and perform a scan with the 3D scanner 30 at each measurement position."

Furthermore, although the above embodiment shows the operation of multiple pairs of mobile bodies 20 and 40, it may also be applied when there is only one pair of mobile bodies 20 and 40. In this case, the grouping of measurement positions in step S4 is skipped. Also, the movement of measurement positions between groups and the corresponding correction processing of calculation results in step S8 are not performed.

In the above embodiment, the case where the number of pairs of mobile bodies 20 and 40 to be used is predetermined was shown. However, it can also be used as a means to determine a suitable number of input pairs when the number of pairs to be used is undetermined. By changing the number of mobile body pairs input in step S1, the travel cost of the best measurement route for different group sizes can be determined in the subsequent processing. Then, the number of mobile body pairs to be used can be determined based on the criterion of the best average travel cost per mobile body pair.

In the above embodiment, a 3D scanner 30 capable of measuring in all directions is used as the measuring instrument, resulting in excellent work efficiency for measurement at each measurement position. However, the measuring instrument is not limited to this. For example, a device such as a handheld scanner with a limited field of view may also be used as the measuring instrument. Depending on the field of view of the measuring instrument, the number and positions of the measurement positions set in step S2 will differ. Consequently, the number and positions of the standby positions determined in step S9 will also differ.

In addition to scanners that emit laser light or other beams of light onto the object, it is also possible to use cameras that capture images of the subject without emitting any light from the device itself as measuring instruments. These cameras can include 360-degree spherical cameras or standard cameras with a narrower field of view.

This invention can be used to create scan data requiring measurements at multiple locations, and is particularly useful when scanning large measurement targets such as buildings and construction sites.

1. Scan data creation system 10: Command creation unit (command creation means)
11 Data receiving unit 12 Data processing unit 12a Measurement position calculation unit 12b Movable information calculation unit 12c Measurement position assignment calculation unit 12d Measurement route calculation unit 12e Calculation result evaluation unit 12f Calculation result correction unit 12g Standby position calculation unit 12h Standby route calculation unit 12i Movement order calculation unit 13 Autonomous movement operation command unit 20 Mobile body (first mobile body)
21 Computer 22 Data receiving unit 23 Autonomous movement command control unit 24 3D scanner operation unit 25 Object sensor 26 Inertial measurement device 27 Driving drive unit 30 3D scanner (measuring instrument)
31 Measurement unit 32 Data storage unit 40 Mobile body (second mobile body)
41 Computer 42 Data receiving unit 43 Autonomous movement command control unit 44 Object sensor 45 Inertial measuring device 46 Driving drive unit 50 Reference sphere 60 Building (object)
61 Outer wall 62 Partition wall H1~H8 Center of gravity position H1~H3, H5, H7, H8 Standby position P1~P12 Measurement position T1~T8 Triangle

Claims (8)

A method for creating scan data, which involves acquiring 3D scan data synthesized using a reference sphere as an indicator in order to create a 3D digital model of an object,
A measurement position calculation step that calculates multiple measurement positions where the object can be measured using a measuring instrument,
A measurement route calculation step that calculates a measurement route that allows the measuring instrument to reach the plurality of measurement locations with the minimum travel cost,
A waiting position calculation step is to calculate multiple waiting positions in which a reference sphere can wait , based on the measurement route, such that the measurement range of the measuring instrument at adjacent measurement positions on the measurement route includes the reference sphere waiting at the same waiting position ,
A waiting route calculation step in which a waiting route is calculated based on the measurement route to reach the reference sphere at the plurality of waiting positions,
A movement sequence calculation step that calculates the movement sequence of the measuring instrument and the reference sphere so that the measurement range of the measuring instrument at adjacent measurement positions on the measurement route includes the reference sphere waiting at the same standby position ,
A method for creating scan data, characterized by performing the following steps. The scan data creation method according to claim 1, characterized in that, in the measurement route calculation step, all edges that can connect the multiple measurement locations by the shortest distance are set, and the measurement route is determined by the minimum spanning tree calculated from all of the edges. The scan data creation method according to claim 2, characterized in that the measurement route calculation step calculates the most efficient movement sequence for following the measurement route and determines it as a measurement route including movement sequence information. The scan data creation method according to any one of claims 1 to 3, characterized in that the standby position calculation step involves calculating the standby position as the centroid of a triangle formed by connecting three adjacent consecutive measurement positions on the measurement route with straight lines. When measuring the object using multiple pairs of the measuring instrument and the reference sphere, the measurement position classification step involves dividing the multiple measurement positions into multiple groups,
After calculating the measurement route for each group in the measurement route calculation step, the measurement route correction step involves changing the measurement locations included in each group and calculating the measurement route again to calculate the grouping that minimizes travel costs.
A method for creating scan data according to any one of claims 1 to 4 , characterized by performing the following. The scan data creation method according to claim 5 , characterized in that the measurement route correction step is performed until the difference between the travel costs of the group with the largest travel cost and the group with the smallest travel cost is minimized. The measuring instrument is mounted on a first mobile body capable of autonomous movement.
The aforementioned reference sphere is mounted on a second mobile body capable of autonomous movement.
A command is sent to the first mobile body to move along the measurement route calculated in the measurement route calculation step in the movement order calculation step, and to perform measurements using the measuring instrument at the measurement positions included in the measurement route.
A command is sent to the second mobile body to move along the waiting route calculated in the waiting route calculation step in the movement order calculated in the movement order calculation step.
A method for creating scan data according to any one of claims 1 to 6 . A scan data creation system that acquires 3D scan data synthesized using a reference sphere as an indicator in order to create a 3D digital model of an object,
Measuring instruments for measuring objects,
Reference ball and,
Instruction creation means,
The first mobile unit,
The second mobile unit,
It has,
The instruction generation means is
A first calculation means calculates a plurality of measurement positions in which the object can be measured, and calculates a measurement route that allows the measuring instrument to reach the plurality of measurement positions with the minimum movement cost,
A second calculation means calculates a plurality of standby positions in which the reference sphere can be stationed , based on the measurement route, such that the measurement range of the measuring instrument at adjacent measurement positions on the measurement route includes the reference sphere stationed at the same standby position , and calculates a standby route to which the reference sphere can reach the plurality of standby positions, based on the measurement route.
a third calculation means for calculating the movement order of the measuring instrument and the reference sphere such that the measurement range of the measuring instrument at adjacent measurement positions on the measurement route includes the reference sphere waiting at the same standby position ,
Includes,
The first mobile body is capable of autonomous movement with the measuring instrument mounted on it, and, upon receiving a command from the command generation means, moves along the measurement route in the specified movement sequence and performs measurement using the measuring instrument at the measurement position.
The second mobile body is capable of autonomous movement with the reference sphere mounted on it, and, upon receiving a command from the command generation means, moves along the waiting route in the specified movement sequence and waits at the waiting position.
A scan data creation system characterized by the following features.