JP7646199B2 - Position measuring device, method and program - Google Patents

Description

The present invention relates to a position measurement device, method, and program.

In recent years, mobile objects such as automated guided vehicles (automated transport vehicles) have been deployed in indoor spaces such as factories or warehouses, and items (luggage) are transported by the mobile objects in order to improve the efficiency of business operations.

In order to have a mobile object transport goods efficiently, it is useful to properly manage the location of the mobile object. However, as described above, when the mobile object moves through an indoor space, it may not be possible to obtain the exact location of the mobile object using, for example, a GPS (Global Positioning System) function.

In consideration of these circumstances, a technology for identifying indoor position information has been disclosed (see, for example, Patent Document 1). However, this technology involves matching a captured image with a target image, so it may not be possible to obtain a highly accurate position.

In response to this, for example, it is conceivable to place an optical recognition code in the indoor space described above, and to calculate the position of the moving object by photographing the optical recognition code with a camera installed on the moving object. However, in this case, it is necessary to measure the position of the optical recognition code in the indoor space in advance, and the task of measuring the position is very complicated.

JP 2016-164518 A

The object of the present invention is to provide a position measurement device, method, and program that can easily measure the position of an optical recognition code used to calculate the position of a moving object.

According to one aspect of the present invention, a position measurement device that measures the position of an optical recognition code captured by a visible light camera installed on a moving body in order to calculate the position of the moving body is provided, the position measurement device comprising: a storage means for storing first position information indicating the position of a first optical recognition code and second position information indicating the position of a second optical recognition code among a plurality of optical recognition codes arranged in an indoor space in which the moving body moves; an acquisition means for acquiring a depth image including first depth information indicating the depth of the first optical recognition code, second depth information indicating the depth of the second optical recognition code, and third depth information indicating the depth of the third optical recognition code by capturing images of the first and second optical recognition codes among the plurality of optical recognition codes and a third optical recognition code different from the first and second optical recognition codes by a depth camera; and a measurement means for measuring the position of the third optical recognition code based on the first and second position information stored in the storage means and the first to third depth information included in the acquired depth image.

The present invention makes it possible to easily measure the position of an optical recognition code that is used to calculate the position of a moving object.

FIG. 1 is a diagram showing an example of the appearance of a moving object moving in an indoor space. FIG. 13 is a diagram for explaining a color bit code. 10 is a flowchart showing an example of a processing procedure for calculating the position of a moving object. 11A and 11B are diagrams for explaining an operation of manually measuring the position of a color bit code. FIG. 2 is a diagram showing an example of a hardware configuration of a position measurement device according to an embodiment of the present invention. FIG. 2 is a diagram showing an example of the functional configuration of a position measurement device. 11 is a flowchart showing an example of a processing procedure of a position measurement device. FIG. 2 is a diagram for explaining an outline of the operation of the position measurement device. FIG. 2 is a diagram for explaining an outline of the operation of the position measurement device. FIG. 2 is a diagram for explaining an outline of the operation of the position measurement device.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
The position measurement device of this embodiment is used to measure the position of an optical recognition code that is used to calculate the position of a moving object moving in an indoor space, for example. Before explaining the position measurement device, the principle of obtaining the position of the moving object in this embodiment will be explained.

Figure 1 shows an example of the appearance of a moving body moving in the indoor space described above. As shown in Figure 1, moving body 1 is configured to be movable by being equipped with wheels, for example. In addition, a camera (imaging device) 1a is installed on moving body 1 in a direction that allows it to capture an image of the outside of moving body 1 (for example, the direction of travel, etc.). Note that camera 1a installed on moving body 1 is a visible light camera that captures color images based on visible light.

In addition, an optical recognition code is placed (attached, drawn, printed, displayed, etc.) in the indoor space in which the mobile object 1 moves. The optical recognition code is placed, for example, on a wall surface that forms the indoor space, but may be placed in another position as long as it is a position where the above-mentioned camera 1a can capture an image.

In this embodiment, the position of the moving body 1 is calculated (obtained) based on an image including an optical recognition code captured by a camera 1a installed on the moving body 1.

The optical recognition code used to calculate the position of the moving body 1 is explained in detail below.

The optical recognition code in this embodiment includes, for example, a code in which multiple elements are formed in a line (rod) shape (hereinafter referred to as a color bit code). This color bit code has a configuration in which multiple cells (elements) are arranged with one color of, for example, three or more colors. According to this color bit code, specific data such as identification information (e.g., ID, etc.) can be represented by the transition of colors assigned to each of the multiple arranged cells.

In the following explanation, the optical recognition code used to calculate the position of a moving object is assumed to be a color bit code.

The above-mentioned color bit code will be described in detail with reference to FIG. 2. Note that in FIG. 2, only a portion of the color bit code is shown for convenience.

As shown in FIG. 2, the color bit code 2 is composed of an array of cells 2a, each of which is colored, for example, with one of the colors red, green, and blue. In FIG. 2, red is indicated as R, green as G, and blue as B. For ease of explanation, FIG. 2 shows an example in which three colors (red, green, and blue) are used in the color bit code 2, but each cell 2a may be colored with a color other than red, green, and blue. Furthermore, the color bit code 2 may be created using four or more colors, as long as the transition of the colors assigned to each cell 2a can be identified.

The cells 2a that make up the color bit code 2 are areas or regions to which one color is applied, and can have various shapes. In the example shown in FIG. 2, each of the multiple cells 2a is rectangular, but they can also be round or triangular, for example. The color bit code 2 is created by arranging multiple such cells 2a in a line (straight line or curved line).

As described above, the color bit code 2 represents specific data by color transitions, so in the color bit code 2, adjacent cells 2a are not given the same color, but different colors. The color bit code 2 is created according to these conditions.

The multiple cells 2a that make up the color bit code 2 include end cells. End cells are cells 2a that are located at the end points (both ends) of the color bit code 2 that is made up of a group of cells 2a connected in a line. A cell 2a in the color bit code 2 is adjacent to two cells 2a, but an end cell is adjacent to only one cell 2a. There are two such end cells in the color bit code 2. Also, the colors assigned to these two end cells are different. This makes it possible to determine whether the end cell is a starting cell 2a (hereinafter referred to as a starting cell) or an ending cell 2a (hereinafter referred to as an ending cell) based on the color assigned to each end cell.

The color bit code 2 described above can express specific data by, for example, a transition (arrangement) of three colors, so there are fewer restrictions on the size and shape of the area occupied by each color in the color bit code 2, and high reading accuracy can be achieved even when the color bit code 2 is attached to, for example, an uneven surface or a flexible material, or is displayed on a display device such as digital signage.

The data represented by the color bit code 2 includes, for example, identification information (hereinafter referred to as a code ID) assigned to the color bit code 2, but may be other data.

Next, an example of a processing procedure for measuring the position of a moving object will be described with reference to the flowchart shown in FIG. 3. Note that the processing shown in FIG. 3 is executed by an image processing device connected to the camera 1a installed on the moving object 1 described above.

When the process shown in FIG. 3 is executed, for example, the power supply of the camera 1a installed on the moving object 1 is turned on and the camera 1a is started. By starting the camera 1a in this manner, it becomes possible to capture an image (color image) with the camera 1a.

As described above, multiple color bit codes 2 are arranged in the indoor space in which the mobile object 1 moves. Therefore, the image processing device acquires from the camera 1a an image including color bit codes 2 that are arranged near the mobile object 1 moving in the indoor space, among the multiple color bit codes 2 (step S1). In the following description, the image acquired in step S1 is conveniently referred to as the target image.

After the process of step S1 is executed, the image processing device executes an image analysis process on the target image (step S2). Note that the image analysis process executed in step S2 corresponds to a decoding process (reading process) on the color bit code 2 included in the target image. As a result, the image processing device acquires a code ID represented by the color transition from the start cell to the end cell in the color bit code 2 included in the target image (i.e., the code ID assigned to the color bit code 2).

For the sake of convenience, in the following description, the code ID obtained by executing the processing of step S2 described above will be referred to as the target code ID, and the color bit code 2 identified by the target code ID (i.e., the color bit code 2 contained in the target image) will be referred to as the target color bit code 2.

When the processing of step S2 is executed, the image processing device obtains the position in real space of the target color bit code 2 based on the target code ID (step S3).

The image processing device stores, for example, a code ID represented by each of a plurality of color bit codes 2 arranged in an indoor space in which the mobile object 1 moves, in association with position information (hereinafter referred to as code position information) indicating the position (in real space) of the color bit code 2. As a result, in step S3, the image processing device can obtain the position of the target color bit code 2 in real space based on the code position information associated with the target code ID. The position of the color bit code 2 in real space is represented, for example, in a three-dimensional coordinate system, and the code position information indicating the position of the color bit code 2 includes the X coordinate value, Y coordinate value, and Z coordinate value corresponding to the position of the color bit code 2.

When the processing of step S3 is executed, the image processing device calculates the position of the moving body 1 (the position of the moving body 1 in real space) (step S4).

Here, it is assumed that multiple color bit codes 2 are arranged in the indoor space in which the mobile body 1 moves, so that at least two color bit codes 2 are included within the angle of view of the camera 1a installed on the mobile body 1.

In this case, the image (target image) acquired in step S1 contains two color bit codes (target color bit codes) 2, and the image analysis process executed in step S2 is capable of extracting the positions (XY coordinate values) on the target image of the two end cells (start cell and end cell) of each of the two target color bit codes 2.

In this case, the positions in real space of each of the two target color bit codes 2 are obtained in step S3, but the image processing device is assumed to store code position information indicating the positions in real space of the cells at both ends of the color bit code 2 (the viewpoint cell and the end cell) for each color bit code 2, and in step S3, the positions in real space of the cells at both ends of each of the two target color bit codes 2 are assumed to be obtained.

According to this, the position of the moving body 1 can be calculated by applying the positions on the target image of the cells at both ends of each of the two target color bit codes 2 described above (four points on the target image) and the positions in real space of the cells at both ends of each of the two target color bit codes 2 (four points in real space) to the perspective projection model. Note that the angle of view of the camera 1a installed on the moving body 1 and the resolution of the image captured by the camera 1a are known, and information relating to the angle of view and resolution is managed within the image processing device. In the process of calculating the position of the moving body 1 described above, information relating to the angle of view and resolution is also used.

That is, in the image processing device, the position of the moving body 1 is calculated using the space defined by the two end cells of each of the two target color bit codes 2 included in the target image (i.e., four points extracted based on the two target color bit codes 2). In this case, the condition for calculating the position of the moving body 1 is that the two end cells of each of the two target color bit codes 2 captured by the camera 1a are not on the same plane, and in the indoor space in which the moving body 1 moves, multiple color bit codes 2 are arranged so that an image that satisfies this condition is captured in relation to the position of the camera 1a.

Note that the method for calculating the position of the moving body 1 described here is just one example, and the position of the moving body 1 may be calculated using other methods.

Furthermore, for the position of the moving body 1, it is sufficient to calculate the X coordinate value, Y coordinate value, and Z coordinate value corresponding to that position, but for example, the vertical tilt angle, horizontal tilt angle, and rotation angle of the camera 1a (the moving body 1 on which it is installed) may also be calculated.

When the processing of step S4 is executed, information indicating the position of the moving body 1 calculated in step S4 (hereinafter referred to as moving body position information) is transmitted to, for example, a server device communicatively connected to the image processing device, and is used, for example, to track (monitor) the moving body 1 or correct the position of the moving body 1.

When calculating the position of the moving object 1 using the color bit code 2 (optical recognition code) as described above, it is necessary to measure the position of the color bit code 2 (in real space) in advance and register the code position information indicating that position.

The position (X coordinate value, Y coordinate value, and Z coordinate value) of each of the multiple color bit codes 2 is determined by determining a reference point (hereinafter referred to as a base point) in the indoor space 3 through which the mobile object 1 moves, as shown in Figure 4, and manually measuring the distance in the X direction, Y direction, and Z direction from the base point to the color bit code 2 using various distance measuring devices (e.g., a tape measure, etc.).

However, the task of manually measuring the position of such a color bit code 2 is extremely cumbersome, and depending on the size of the indoor space in which the mobile object 1 moves, the task can take a very long time.

Furthermore, when the position of the color bit code 2 is measured manually as described above, the position of the measured color bit code 2 (i.e., the correspondence between the color bit code and the position of the color bit code) must also be input (registered) manually, which may lead to erroneous input. Incorrect input of the position of the color bit code 2 can reduce the accuracy of calculation of the position of the moving body 1.

The position measurement device according to this embodiment is therefore used to improve the ease of measuring the position of the color bit code 2 described above.

The position measurement device according to this embodiment will be described below. Note that in the following description, it will simply be described as "measuring the position of the color bit code 2", but if the positions of the cells at both ends of the color bit code 2 are used when calculating the position of the moving body 1, the "position of the color bit code 2" described below will be the positions of the cells at both ends of the color bit code 2 as described above.

Figure 5 shows an example of the hardware configuration of a position measurement device according to this embodiment. As shown in Figure 5, the position measurement device 10 includes a non-volatile memory 11, a CPU 12, a main memory 13, a communication device 14, and a depth camera 15.

The non-volatile memory 11 stores various programs. The various programs stored in the non-volatile memory 11 include software that runs on the position measurement device 10.

The CPU 12 executes various programs stored in, for example, the non-volatile memory 11. The CPU 12 is responsible for controlling the entire position measurement device 10.

The main memory 13 is used, for example, as a work area required when the CPU 12 executes various programs.

The communication device 14 has the function of communicating with devices external to the position measurement device 10, for example.

The depth camera 15 is a camera with a built-in depth sensor that acquires depth information indicating the depth to a subject when the subject is imaged by the depth camera 15. The depth information includes information such as the distance from the depth camera 15 to the subject and the direction in which the subject is located relative to the depth camera 15. The depth camera 15 is configured to output an image including depth information indicating the depth of the subject (hereinafter referred to as a depth image) by imaging the subject. The depth camera 15 is also referred to as, for example, a three-dimensional spatial seismic intensity measurement sensor.

In FIG. 5, the position measurement device 10 is described as being equipped with the depth camera 15, but for example, the depth camera 15 may be provided outside the position measurement device 10. In this case, the position measurement device 10 only needs to be configured to communicate with the depth camera 15 and acquire the depth image output from the depth camera 15.

Figure 6 shows an example of the functional configuration of the position measurement device 10. As shown in Figure 6, the position measurement device 10 includes a storage unit 101, an image acquisition unit 102, a decode processing unit 103, a code position acquisition unit 104, a code position measurement unit 105, and a registration processing unit 106.

In this embodiment, the storage unit 101 is realized, for example, by the non-volatile memory 11 shown in FIG. 5.

In addition, in this embodiment, the image acquisition unit 102, the decode processing unit 103, the code position acquisition unit 104, the code position measurement unit 105, and the registration processing unit 106 are realized by, for example, the CPU 12 (i.e., the computer of the position measurement device 10) shown in FIG. 5 executing a predetermined program stored in the non-volatile memory 11, that is, by software. Note that the program executed by this CPU 12 may be distributed by being stored in advance in a computer-readable storage medium, or may be downloaded to the position measurement device 10 via a network.

The storage unit 101 stores code position information indicating the positions of at least two color bit codes 2 out of a plurality of color bit codes 2 arranged in an indoor space in which the mobile object 1 moves. The code position information indicating the position of each of the two color bit codes 2 is registered in advance in the storage unit 101 by manually measuring the distances from a base point to the color bit code 2 in the X-direction, Y-direction, and Z-direction. The code position information is stored in the storage unit 101 in association with the code ID represented by the color bit code 2 whose position is indicated by the code position information.

The image acquisition unit 102 acquires a depth image output from the depth camera 15 described above. The depth image acquired by the image acquisition unit 102 is a depth image output from the depth camera 15 by capturing images of at least the two color bit codes 2 described above (color bit codes for which code position information has already been registered) and a color bit code 2 different from the two color bit codes 2 (color bit code for which code position information has not yet been registered). Since the depth camera 15 has the depth sensor described above built in, the depth image acquired by the image acquisition unit 102 includes depth information indicating the depths (distances and directions from the depth camera 15) of the three color bit codes 2 captured by the depth camera 15.

The decode processing unit 103 executes a process of reading (decoding) the three color bit codes 2 captured by the depth camera 15 based on the depth image acquired by the image acquisition unit 102. The decoding by the decode processing unit 103 is performed based on the color transitions in the color bit codes 3 (i.e., the color transitions applied to each of the multiple cells 2a that make up the color bit code 2). In this way, the decode processing unit 103 acquires the code ID represented by each of the color bit codes 2 captured by the depth camera 15.

The code position acquisition unit 104 acquires code position information associated with the code ID acquired by the decoding processing unit 103 from the storage unit 101.

The code position measurement unit 105 measures the position of a color bit code for which code position information is not registered, based on the code position information acquired from the storage unit 101 and the depth information contained in the depth image acquired by the image acquisition unit 102.

The registration processing unit 106 registers (adds) the code position information indicating the position of the color bit code 2 measured by the code position measurement unit 105 in the storage unit 101.

Below, an example of the processing procedure of the position measurement device 10 according to this embodiment will be described with reference to the flowchart in Figure 7.

First, before the process of FIG. 7 is executed, multiple color bit codes 2 are placed in the indoor space in which the mobile object 1 moves. Note that the multiple color bit codes 2 are placed at intervals such that at least two color bit codes 2 are included within the angle of view of the camera 1a installed on the mobile object 1, for example.

When multiple color bit codes 2 are placed in an indoor space as described above, a base point is set (confirmed) in the indoor space, and the positions of, for example, two color bit codes 2 (hereinafter referred to as the first and second color bit codes) 2 among the multiple color bit codes 2 based on the base point are measured manually (such as a user using the position measurement device 10).

The code position information indicating the position of the first color bit code 2 measured manually as described above is registered as an initial value in the storage unit 101 in association with the code ID represented by the first color bit code 2 (the code ID assigned to the color bit code 2) (step S11). The same applies to the code position information indicating the position of the second color bit code 2.

When the process of step S11 is executed, measurement of the positions of color bit codes 2 other than the first and second color bit codes 2 described above is started. Here, if a third color bit code 2 is placed near the first and second color bit codes 2, for example, the depth camera 15 captures the first to third color bit codes 2 (or the area including them) from, for example, a base point in response to the user's operation described above. When the first to third color bit codes are captured by the depth camera 15 in this manner, the image acquisition unit 102 acquires the depth image output from the depth camera 15 (step S12).

Next, the decode processing unit 103 executes an image analysis process on the depth image acquired in step S12 to acquire the code ID represented by the color bit code 2 captured by the depth camera 15 (step S13). Note that the process of step S13 is the same as step S2 shown in FIG. 3, and therefore a detailed description thereof will be omitted here. When the depth camera 15 captures the first to third color bit codes 2 as described above, the decode processing unit 103 acquires the code ID represented by each of the first to third color bit codes 2.

When the process of step S13 is executed, the code position acquisition unit 104 acquires the code position information stored in the storage unit 101 in association with the code ID acquired in step S13 (step S14).

Here, in step S11 described above, code position information indicating the positions of the first and second color bit codes (hereinafter referred to as code position information of the first and second color bit codes) is registered in the storage unit 101, but code position information indicating the position of the third color bit code (hereinafter referred to as code position information of the third color bit code) is not registered in the storage unit 101. Therefore, in step S14, the code position information of the first and second color bit codes is acquired.

Next, the code position measurement unit 105 measures (calculates) the position of the third color bit code 2 based on the code position information acquired in step S14 and the depth information indicating the depth of the first to third color bit codes 2 included in the depth image acquired in step S12 (hereinafter referred to as the depth information of the first to third color bit codes 2) (step S15). Note that in step S15, for example, a process is performed to convert the depth information of the third color bit code 2 into code position information (X coordinate value, Y coordinate value, and Z coordinate value) of the third color bit code 2 based on the correspondence between the code position information of the first and second color bit codes 2 and the depth information of the first and second color bit codes 2.

When the process of step S15 is executed, the code position information (code position information of the third color bit code) indicating the position of the third color bit code 2 measured in step S15 is registered in the storage unit 101 in correspondence with the code ID represented by the third color bit code 2 (step S16).

When the process of step S16 is executed, for example, it is determined whether or not to end the measurement of the position of the color bit code 2 (step S17).

In step S17, for example, if a user of the position measurement device 10 issues an instruction to end the measurement of the position of the color bit code 2, it is determined that the measurement is to be ended (YES in step S17), and the process shown in FIG. 7 is ended.

On the other hand, if it is determined that the measurement of the positions of the color bit codes is not to be ended (NO in step S17), the process returns to step S12 and is repeated. In this case, the code position information of the first to third color bit codes 2 is registered (stored) in the storage unit 101, but in step S12, the depth camera 15 captures at least two of the first to third color bit codes 2 and a color bit code different from the first to third color bit codes 2 (i.e., a color bit code whose code position information is not registered), thereby acquiring a depth image output from the depth camera 15. Thereafter, the process from step S13 onwards is executed, thereby making it possible to measure the position of the color bit code 2 different from the first to third color bit codes 2.

The operation of the position measurement device 10 according to this embodiment will be outlined below with reference to Figs. 8 to 10. Here, it is assumed that the multiple color bit codes 2 placed in the indoor space 3 are color bit codes 21 to 26. It is also assumed that the code position information of color bit codes 21 and 22 is stored (registered) in the storage unit 101 as the initial value of the position measurement device 10.

In addition, in Figures 8 to 10, color bit codes 2 for which code position information has already been registered are represented by hatching.

As this has been explained above in FIG. 7, a detailed explanation will be omitted, but when the code position information of color bit codes 21 and 22 is registered in storage unit 101, the position of color bit code 23 is measured by photographing the area including color bit codes 21 to 23 with depth camera 15 as shown in FIG. 8, and the code position information of color bit code 23 is registered in storage unit 101.

When the code position information of the color bit code 23 is registered in the storage unit 101 as described above, the position of the color bit code 24 is measured by, for example, photographing an area including the color bit codes 22 to 24 with the depth camera 15 as shown in FIG. 9, and the code position information of the color bit code 24 is registered in the storage unit 101.

When the code position information of color bit code 24 is registered in storage unit 101 as described above, the positions of color bit codes 25 and 26 are measured by, for example, photographing an area including color bit codes 23 to 26 with depth camera 15 as shown in FIG. 10, and the code position information of color bit codes 25 and 26 is registered in storage unit 101. In the example shown in FIG. 10, the position of color bit code 25 is measured using the code position information of color bit codes 23 and 24 and the depth information of color bit codes 23 to 25. On the other hand, the position of color bit code 26 is measured using the code position information of color bit codes 23 and 24 and the depth information of color bit codes 23, 24, and 26.

In other words, in this embodiment, in order to measure the position of the color bit code 2, it is sufficient that at least two color bit codes 2 for which code position information is registered and at least one color bit code 2 for which code position information is not registered are imaged by the depth camera 15.

As described above, in this embodiment, among the multiple color bit codes 2 (optical recognition codes) arranged in the indoor space in which the mobile object 1 moves, the code position information (first position information indicating the position of the first color bit code 2) of the first color bit code 2 and the code position information (second position information indicating the position of the second color bit code 2) of the second color bit code 2 are stored in the storage unit 101, and the first to third color bit codes 2 are imaged by the depth camera 15 to obtain a depth image including the depth information (first to third depth information) of the first to third color bit codes 2, and the position of the third color bit code is measured based on the code position information of the first and second color bit codes 2 and the depth information of the first to third color bit codes 2.

In this embodiment, this configuration makes it possible to easily measure the position of the color bit code 2 (optical recognition code) used to calculate the position of the moving object 1.

In this embodiment, as described above, by repeating the operation (processing) of photographing at least two color bit codes 2 for which code position information is registered and at least one color bit code 2 for which code position information is not registered with the depth camera 15 and measuring the position of the color bit code 2 for which code position information is not registered, the position of each of the color bit codes 2 can be easily measured even if a large number of color bit codes 2 are placed in a large indoor space.

In other words, in this embodiment, only two of the multiple color bit codes 2 are manually measured, and the color bit codes 2 only need to be photographed using the depth camera 15, so the ease of position measurement can be dramatically improved compared to the case where all of the positions of the multiple color bit codes 2 are manually measured as described in Figure 4.

In addition, in this embodiment, the code position information indicating the position of the color bit code 2 measured by the position measurement device 10 is automatically registered, so that it is possible to prevent the position (code position information) from being erroneously registered manually. In other words, according to this embodiment, it is possible to reduce erroneous registrations (mistakes) caused by human work.

Furthermore, in this embodiment, after the positions of the multiple color bit codes 2 are measured using the position measurement device 10 and the code position information of the multiple color bit codes 2 is registered (i.e., the image processing device is operated to calculate the position of the moving body 1), when checking whether or not there is any deviation in each position, it is only necessary to take a depth image with the depth camera 15, so that the position deviation can be easily checked.

In this embodiment, at least three color bit codes 2 (two color bit codes 2 for which code position information is registered and one color bit code 2 for which code position information is not registered) are captured within the field of view of the depth camera 15. If the three color bit codes 2 are not within the field of view, the three color bit codes 2 may be captured while rotating the depth camera 15 (i.e., panoramic capture).

In addition, in this embodiment, the error increases as one moves away from the base point (i.e., measuring the position of the color bit code 2 farther from the base point), but when measuring the position of the color bit code 2 farther from the base point, for example, a predetermined algorithm that minimizes the error may be applied to improve the measurement accuracy of the position.

In the present embodiment, a base point is first determined, and then the positions of the two color bit codes in real space based on the base point are manually measured (hereinafter referred to as measurement work), and the code position information indicating the positions of the two color bit codes in real space is registered as an initial value in the storage unit 101, after which the color bit code 2 is photographed by the depth camera 15. However, the position measurement device 10 according to the present embodiment is also capable of executing a process that enables the above-mentioned measurement work to be performed after photographing the color bit code 2 by the depth camera 15.

The following describes the processing procedure of the position measurement device 10 (hereinafter, referred to as the position measurement device 10 according to the modified example of this embodiment) when performing measurement work after photographing the color bit code 2 with the depth camera 15. Note that in the following description, detailed explanations of parts similar to the processing of the position measurement device 10 according to the present embodiment described above will be omitted.

In a modified example of this embodiment, first, from a predetermined position in an indoor space in which a moving object 1 is moving, the depth camera 2 captures an image of two color bit codes (first and second color bit codes 2) out of a plurality of color bit codes 2 arranged in the indoor space. When the first and second color bit codes 2 are captured by the depth camera 15 in this manner, the image acquisition unit 102 acquires the depth image output from the depth camera 15.

Next, the decoding processing unit 103 performs image analysis processing on the depth image acquired by the image acquisition unit 102 to acquire the code ID represented by each of the first and second color bit codes 2 captured by the depth camera 15 described above.

Here, the depth image acquired by the image acquisition unit 102 includes depth information (first depth information) indicating the depth of the first color bit code 2 and depth information (second depth information) indicating the depth of the second color bit code. Therefore, the code position acquisition unit 104 acquires the positions of the first and second color bit codes 2 in virtual space, for example, based on the position of the depth camera 15, based on the first and second depth information included in the depth image. The code position information indicating the positions of the first and second color bit codes 2 in virtual space acquired by the code position acquisition unit 104 in this manner is stored in the storage unit 101 in association with the code ID represented by each of the first and second color bit codes 2 acquired by the decoding processing unit 103.

Next, when a third color bit code 2 is arranged near the first and second color bit codes 2, the depth camera 15 captures the first to third color bit codes 2 (the area including them). When the first to third color bit codes are captured by the depth camera 15 in this manner, the image acquisition unit 102 acquires the depth image output from the depth camera 15.

Next, the decode processing unit 103 performs image analysis processing on the depth image acquired by the image acquisition unit 102 to acquire the code ID represented by each of the first to third color bit codes captured by the depth camera 15.

In this case, the code position acquisition unit 104 acquires the code position information registered in the storage unit 101 based on the code ID acquired by the decoding processing unit 103 described above, and acquires the position of the third color bit code 2 in the virtual space based on the positions of the first and second color bit codes 2 in the virtual space indicated by the code position information and the depth information (first to third depth information) indicating the depths of the first to third color bit codes 2 included in the depth image acquired by the image acquisition unit 102. The position of the third color bit code 2 in the virtual space is acquired (calculated) by executing a process equivalent to the process of step S15 shown in FIG. 7 described above. The code position information indicating the position of the third color bit code 2 in the virtual space acquired by the code position acquisition unit 104 is stored in the storage unit 101 in association with the code ID represented by the third color bit code 2 acquired by the decoding processing unit 103.

Then, by sequentially photographing at least two color bit codes 2 for which code position information (position in virtual space) is registered and at least one color bit code 2 for which code position information (position in virtual space) is not registered using the depth camera 15, code position information indicating the positions in virtual space of each of all color bit codes 2 placed in the indoor space is stored in the storage unit 101.

In a modified example of this embodiment, after the code position information indicating the position in virtual space of each of the multiple color bit codes 2 is stored (registered) in the storage unit 101 as described above, the positions in real space (positions based on the base point) of two color bit codes (e.g., the first and second color bit codes) among the multiple color bit codes are manually measured. The code position information indicating the positions in real space of the two color bit codes thus manually measured is registered (stored) in the storage unit 101. Note that the base point may be set (confirmed) before the code position information indicating the position in virtual space of each of the multiple color bit codes 2 described above is stored in the storage unit 101, or may be set after the code position information is stored in the storage unit 101.

In this case, the code position measurement unit 105 corrects the virtual space positions of each of the multiple color bit codes 2 (color bit codes 2 other than the first and second color bit codes 2) indicated by the code position information stored in the storage unit 101 to positions in real space based on the real space positions of the first and second color bit codes 2 described above. Note that the code position measurement unit 105 executes a process of converting the virtual space positions of the other color bit codes 2 to real space positions, for example, based on the correspondence between the real space positions of the first and second color bit codes 2 and the virtual space positions.

The registration processing unit 106 registers in the storage unit 101 code position information indicating the position in real space of each color bit code 2 obtained (i.e., measured) by correcting the position in virtual space by the code position measurement unit 105.

As described above, in the modified embodiment, the first depth image is acquired by capturing images of the first and second color bit codes 2 by the depth camera 15, and the positions of the first and second color bit codes 2 in the virtual space are acquired based on the first and second depth information included in the acquired first depth image, and the second depth image is acquired by capturing images of the first to third color bit codes 2 by the depth camera 15, and the position of the third color bit code in the virtual space is acquired based on the positions of the virtual space information of the first and second color bit codes 2 and the first to third depth information included in the acquired second depth image. In the modified embodiment, the position of the third color bit code in the real space is measured by correcting the position of the third color bit code 2 in the virtual space based on the positions of the first and second color bit codes 2 in the real space measured manually and the positions of the first to third color bit codes 2 in the virtual space described above.

That is, the position measurement device 10 according to the above-described embodiment measures the position of the third color bit code 2 in real space based on the depth (information) of the third color bit code 2 relative to the positions of the first and second color bit codes 2 in real space, whereas the position measurement device 10 according to the modified embodiment of the present invention measures the position of the third color bit code 2 in real space by correcting the position of the third color bit code 2 in virtual space based on the positions of the first and second color bit codes 2 in real space.

Even with the configuration of the position measurement device 10 according to the modified example of this embodiment described above, it is possible to easily measure the position of the color bit code 2 used to calculate the position of the moving body 1, just like in this embodiment.

Note that in this modified embodiment, unlike the present embodiment described above, it is not necessary to register the real space positions (or the code position information indicating) of the two color bit codes 2 (first and second color bit codes) in the storage unit 101 before photographing the color bit codes 2 with the depth camera 15. However, the position measurement device 10 according to the modified embodiment of the present embodiment only needs to be configured to use the real space positions of at least two color bit codes 2 to correct the virtual space position of other color bit codes 2, and does not prevent the real space position of the color bit code 2 from being measured in advance.

In the above embodiment, the code position information is registered in the storage unit 101 included in the position measurement device 10. However, if the code position information is used by the image processing device to calculate the position of the moving body 1, it may be transmitted from the position measurement device 10 to an external server device (e.g., a cloud server that provides a cloud computing service) and managed by the server device.

In addition, in this embodiment, the position of the color bit code 2 (optical recognition code) arranged in an indoor space is measured to calculate the position of the moving object 1, but this embodiment can also be used to measure the positions of various reference points (color bit codes 2 attached to them) in radio wave-based positioning. Specifically, this embodiment can be used, for example, in the initial position setting work of a reference radio wave device used in an indoor positioning system.

In addition, since this embodiment can be used to check the positional misalignment of the color bit code 2 as described above, this embodiment may also be used to verify the positional misalignment of various reference points in existing systems.

In this embodiment, the color bit code 2 is used as the optical recognition code, but other optical recognition codes (automatic recognition technology), such as bar codes or two-dimensional codes, may also be used as the optical recognition code.

Furthermore, in this embodiment, the optical recognition code (the part whose position is to be measured) placed in the indoor space may be created using, for example, a retroreflector (tape). This makes it possible to take advantage of the property of light from the retroreflector returning toward the light source (depth camera 15) and to expand the range of optical recognition codes (i.e., the distance to the optical recognition code) whose position can be measured in one shot by the depth camera 15. Note that when a retroreflector is used, highly accurate position measurement can be achieved even in an environment where, for example, ambient light during the day enters the indoor space.

In addition, in this embodiment, the depth information of the optical recognition code (depth information included in the depth image) acquired by the depth camera 15 is used to measure the position of the optical recognition code, but the depth information of the optical recognition code may be acquired by a visible light camera such as the camera 1a installed on the mobile body 1. In this case, for example, the depth information of the optical recognition code can be obtained by applying a triangulation technique to two optical recognition codes captured by a visible light camera at different points.

The various configurations applicable to this embodiment described here may also be applied to the modified examples of this embodiment described above.

The techniques described in the above embodiments can also be distributed as a program that can be executed by a computer, stored on a storage medium such as a magnetic disk (e.g., a floppy disk, a hard disk, etc.), an optical disk (e.g., a CD-ROM, a DVD), a magneto-optical disk (MO), or a semiconductor memory.

In addition, this storage medium may be in any storage format as long as it is capable of storing a program and is computer-readable.

In addition, an OS (operating system), database management software, network software, or other MW (middleware) running on a computer may execute some of the processes for implementing this embodiment based on instructions from a program installed on the computer from a storage medium.

Furthermore, the storage medium in the present invention is not limited to a medium independent of a computer, but also includes a storage medium that stores or temporarily stores a program downloaded from a LAN, the Internet, etc.

In addition, the number of storage media is not limited to one, and the processing in this embodiment can be performed from multiple media, and the storage media in this invention can have any configuration.

The computer in the present invention executes each process in this embodiment based on a program stored in a storage medium, and may be configured as either a single device such as a personal computer, or a system in which multiple devices are connected to a network.

In addition, the computer in this invention is not limited to a personal computer, but also includes an arithmetic processing unit, a microcomputer, etc. included in information processing equipment, and is a general term for equipment or devices that can realize the functions of this invention by a program.

The present invention is not limited to the above-described embodiment as it is, and in the implementation stage, the components can be modified to the extent that does not deviate from the gist of the invention. In addition, various inventions can be formed by appropriate combinations of multiple components disclosed in the above-described embodiment. For example, some components may be deleted from all of the components shown in the embodiment. Furthermore, components from different embodiments may be appropriately combined.

1...mobile body, 1a...camera (visible light camera), 2, 21-26...color bit code (optical recognition code), 3...indoor space, 4...base point, 10...position measurement device, 11...non-volatile memory, 12...CPU, 13...main memory, 14...communication device, 15...depth camera, 101...storage unit, 102...image acquisition unit, 103...decoding processing unit, 104...code position acquisition unit, 105...code position measurement unit, 106...registration processing unit.

Claims (6)

A position measurement device that measures a position of an optical recognition code captured by a visible light camera installed on a moving object in order to calculate the position of the moving object, comprising:
a storage means for storing first position information indicating a position of a first optical recognition code and second position information indicating a position of a second optical recognition code among a plurality of optical recognition codes arranged in an indoor space in which the moving object moves;
an acquisition means for acquiring a depth image including first depth information indicating a depth of the first optical recognition code, second depth information indicating a depth of the second optical recognition code, and third depth information indicating a depth of the third optical recognition code by capturing images of the first and second optical recognition codes among the plurality of optical recognition codes and a third optical recognition code different from the first and second optical recognition codes with a depth camera;
and a measuring means for measuring the position of the third optical recognition code based on the first and second position information stored in the storage means and the first to third depth information included in the acquired depth image. A position measurement device that measures a position of an optical recognition code captured by a visible light camera installed on a moving object in order to calculate the position of the moving object, comprising:
a first acquisition means for acquiring a first depth image including first depth information indicating a depth of the first optical recognition code and second depth information indicating a depth of the second optical recognition code by capturing images of first and second optical recognition codes among a plurality of optical recognition codes arranged in an indoor space in which the moving object moves using a depth camera;
a second acquisition means for acquiring positions of the first and second optical recognition codes in a virtual space based on first and second depth information included in the acquired first depth image;
a third acquisition means for acquiring a second depth image including first depth information indicating a depth of the first optical recognition code, second depth information indicating a depth of the second optical recognition code, and third depth information indicating a depth of the third optical recognition code by capturing images of first and second optical recognition codes among the plurality of optical recognition codes and a third optical recognition code different from the first and second optical recognition codes by the depth camera;
a fourth acquisition means for acquiring a position of the third optical recognition code in a virtual space based on positions of the first and second optical recognition codes in a virtual space and the first to third depth information included in the acquired second depth image;
a storage means for storing first position information indicating a position of the first optical recognition code in real space and second position information indicating a position of the second optical recognition code in real space;
and a correction means for correcting the position of the third optical recognition code in the virtual space to a position in real space based on the positions of each of the first to third optical recognition codes in the virtual space and the first and second position information stored in the storage means. A method for calculating a position of a moving object by a position measurement device that measures a position of an optical recognition code captured by a visible light camera installed on the moving object, the method comprising the steps of:
storing in a storage device first position information indicating a position of a first optical recognition code and second position information indicating a position of a second optical recognition code among a plurality of optical recognition codes arranged in an indoor space in which the moving object moves;
a step of acquiring a depth image including first depth information indicating a depth of the first optical recognition code, second depth information indicating a depth of the second optical recognition code, and third depth information indicating a depth of the third optical recognition code by capturing images of the first and second optical recognition codes and a third optical recognition code different from the first and second optical recognition codes with a depth camera;
and measuring the position of the third optical recognition code based on the first and second position information stored in the storage means and the first to third depth information included in the acquired depth image. A method for calculating a position of a moving object by a position measurement device that measures a position of an optical recognition code captured by a visible light camera installed on the moving object, the method comprising the steps of:
a step of acquiring a first depth image including first depth information indicating a depth of the first optical recognition code and second depth information indicating a depth of the second optical recognition code by capturing images of first and second optical recognition codes among a plurality of optical recognition codes arranged in an indoor space in which the moving object moves using a depth camera;
acquiring positions of the first and second optical recognition codes in a virtual space based on first and second depth information included in the acquired first depth image;
a step of acquiring a second depth image including first depth information indicating a depth of the first optical recognition code, second depth information indicating a depth of the second optical recognition code, and third depth information indicating a depth of the third optical recognition code by capturing images of first and second optical recognition codes among the plurality of optical recognition codes and a third optical recognition code different from the first and second optical recognition codes by the depth camera;
acquiring a position of the third optical recognition code in a virtual space based on positions of the first and second optical recognition codes in a virtual space and the first to third depth information included in the acquired second depth image;
storing, in a storage means, first position information indicating a position of the first optical recognition code in real space and second position information indicating a position of the second optical recognition code in real space;
and correcting the position of the third optical recognition code in the virtual space to a position in real space based on the positions of each of the first to third optical recognition codes in the virtual space and the first and second position information stored in the storage means. A program executed by a computer of a position measurement device that measures a position of an optical recognition code captured by a visible light camera installed on a moving object in order to calculate the position of the moving object,
The computer includes:
storing in a storage device first position information indicating a position of a first optical recognition code and second position information indicating a position of a second optical recognition code among a plurality of optical recognition codes arranged in an indoor space in which the moving object moves;
a step of acquiring a depth image including first depth information indicating a depth of the first optical recognition code, second depth information indicating a depth of the second optical recognition code, and third depth information indicating a depth of the third optical recognition code by capturing images of the first and second optical recognition codes and a third optical recognition code different from the first and second optical recognition codes with a depth camera;
and a step of measuring the position of the third optical recognition code based on the first and second position information stored in the storage means and the first to third depth information included in the acquired depth image. A program executed by a computer of a position measurement device that measures a position of an optical recognition code captured by a visible light camera installed on a moving object in order to calculate the position of the moving object,
The computer includes:
a step of acquiring a first depth image including first depth information indicating a depth of the first optical recognition code and second depth information indicating a depth of the second optical recognition code by capturing images of first and second optical recognition codes among a plurality of optical recognition codes arranged in an indoor space in which the moving object moves using a depth camera;
acquiring positions of the first and second optical recognition codes in a virtual space based on first and second depth information included in the acquired first depth image;
a step of acquiring a second depth image including first depth information indicating a depth of the first optical recognition code, second depth information indicating a depth of the second optical recognition code, and third depth information indicating a depth of the third optical recognition code by capturing images of first and second optical recognition codes among the plurality of optical recognition codes and a third optical recognition code different from the first and second optical recognition codes by the depth camera;
acquiring a position of the third optical recognition code in a virtual space based on positions of the first and second optical recognition codes in a virtual space and the first to third depth information included in the acquired second depth image;
storing, in a storage means, first position information indicating a position of the first optical recognition code in real space and second position information indicating a position of the second optical recognition code in real space;
and a step of correcting the position of the third optical recognition code in the virtual space to a position in real space based on the positions of each of the first to third optical recognition codes in the virtual space and the first and second position information stored in the storage means.

Images