Mark emitting device and moving body

Abstract

To provide a mark emitting device and a moving body capable of measuring a position or an attitude without installing a physical marker.SOLUTION: The measurement system 1 includes a mark emission unit 20 that emits a plurality of laser beams, an imaging unit 30 that images a plurality of marks 101 formed by the laser beams emitted by the mark emission unit 20 and applied to a measurement object, and a calculation unit 50 that calculates a relative positional relationship between the imaging unit 30 and the marks 101 by using images of the imaged plurality of marks 101.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a mark emission device and a moving body that measure the relative positional relationship between an observation position and a measurement object. [Background technology]

[0002] Conventionally, there has been known a technique for determining the position and orientation of a marker based on a plurality of reference points (for example, Patent Document 1). Also, a method for installing an AR marker has been disclosed in which an AR marker is projected onto a projection position on the tunnel wall surface in order to display information about the tunnel on the tunnel wall surface (Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-102246 [Patent Document 2] Japanese Patent Publication No. 2020-84654 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology of Patent Document 1 requires the installation of physical markers, which can be cumbersome and difficult to install, making it unusable in some cases. Furthermore, the projected AR marker in Patent Document 2 is only used as a reference for displaying information, and cannot be used for measurements such as determining position and orientation.

[0005] An object of the present invention is to provide a mark emission device and a moving body that can measure the position or attitude without installing a physical marker. [Means for solving the problem]

[0006] The present invention solves the above-mentioned problems by the following means: For ease of understanding, the following description will be given with reference to the corresponding embodiments of the present invention, but the present invention is not limited to these.

[0007] The first invention is a measurement system (1) comprising a mark emitting unit (20) that emits multiple laser beams, an imaging unit (30) that photographs multiple marks formed by the laser beams emitted by the mark emitting unit (20) and irradiated onto an object to be measured, and a calculation unit (50) that calculates the relative positional relationship between the imaging unit (30) and the marks using the photographed images of the multiple marks.

[0008] The second invention is the measurement system (1) according to the first invention, characterized in that the mark emission unit (20) emits parallel laser beams in a state parallel to each other at a predetermined interval.

[0009] The third invention is the measurement system (1) according to the first or second invention, characterized in that the mark emission unit (20) emits three or more laser beams.

[0010] The fourth invention is a measurement system (1) according to any one of the first to third inventions, characterized in that the mark emission unit (20), the photographing unit (30), and the calculation unit (50) are provided on a movable body (10).

[0011] The fifth invention is a measurement system (1) according to the fourth invention, characterized in that the moving body (10) is provided with a plurality of at least one of the mark emission unit (20), the photographing unit (30), and the calculation unit (50).

[0012] The sixth invention is a measurement system (1) according to the fourth or fifth invention, characterized in that the mark emission unit (20) emits the mark at a plurality of different positions as the moving body (10) moves, and the calculation unit (50) calculates the relative positional relationship between the mark emitted at the plurality of different positions and the photographing unit (30) in association with the movement of the moving body (10).

[0013] A seventh invention is a measurement system (1) according to any one of the fourth to sixth inventions, characterized in that it further comprises a control unit (60) that controls the moving body (10) based on the calculation results of the calculation unit (50).

[0014] The eighth invention is the measurement system (1) described in the seventh invention, characterized in that the control unit (60) controls the movement of the moving body (10) based on the calculation result of the calculation unit (50) so that the laser light emitted by the mark emission unit (20) is emitted in the normal direction of the object to be irradiated.

[0015] A ninth aspect of the present invention is a moving body (10) used in the measurement system (1) according to any one of the fourth to eighth aspects of the present invention.

[0016] The tenth invention is a measurement method comprising the steps of: a step in which a mark emitting unit (20) emits a plurality of laser beams; a step in which an imaging unit (30) photographs a plurality of marks formed by the laser beams emitted by the mark emitting unit (20) and irradiated onto the object to be measured; and a step in which a calculation unit (50) calculates the relative positional relationship between the imaging unit (30) and the marks using the photographed images of the plurality of marks.

[0017] The eleventh invention is a measurement program for causing a computer to execute the following steps: a step in which a mark emitting unit (20) emits a plurality of laser beams; a step in which an imaging unit (30) photographs a plurality of marks formed by the laser beams emitted by the mark emitting unit (20) and irradiated onto an object to be measured; and a step in which a calculation unit (50) calculates the relative positional relationship between the imaging unit (30) and the marks using the photographed images of the plurality of marks. [Effects of the Invention]

[0018] According to the present invention, it is possible to provide a measurement system, a measurement method, and a measurement program that can measure a position or a posture without installing a physical marker. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a diagram showing an overview of a measurement system 1 according to a first embodiment. [Figure 2] 1 is a block diagram showing the configuration of a measurement system 1 according to a first embodiment. [Figure 3] 2 is a diagram showing the internal configuration of the mark emission unit 20. FIG. [Figure 4] 3 is a flowchart showing the flow of operations of the measurement system 1. [Figure 5] FIG. 10 is a diagram showing an overview of a measurement system according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.

[0021] (First embodiment) FIG. 1 is a diagram showing an overview of a measurement system 1 according to the first embodiment. FIG. 2 is a block diagram showing the configuration of the measurement system 1 of the first embodiment. Note that the figures shown below, including Figure 1, are schematic diagrams, and the size and shape of each part are exaggerated or omitted as appropriate to make them easier to understand. In the following description, specific numerical values, shapes, materials, etc. are given, but these can be changed as appropriate. In addition, in the drawings, orthogonal coordinates of up and down (vertical direction), left and right (horizontal direction), and front and back (horizontal direction) are appropriately shown to make the orientation in use easier to understand.

[0022] The measurement system 1 of this embodiment includes a moving object 10, a mark emitting unit 20, an imaging unit 30, a GPS antenna 40, a calculation unit 50, a control unit 60, and a driving unit 70. Fig. 1 shows a state in which the mark emitting unit 20 emits laser light to form a marker 100 on a wall W. Note that Fig. 1 illustrates an example in which the wall W is a wall surface along the vertical direction.

[0023] The mobile object 10 can move under the control of a control unit 60, which will be described later. In the example of Fig. 1, the mobile object 10 is provided with wheels 11 and is capable of traveling on a floor, road, ground, etc., and examples thereof include an automated guided vehicle (AGV) and a robot vacuum cleaner. Note that the mobile object 10 is not limited to a form provided with wheels 11, and may be, for example, an unmanned aerial vehicle (drone) equipped with propellers and capable of flight.

[0024] The mark emitting unit 20 emits a plurality of laser beams, and these laser beams form markers 100 on the surface of the irradiation target. FIG. 3 is a diagram showing the internal configuration of the mark emission unit 20. As shown in FIG. In this embodiment, four laser pointers 22 are arranged in a square at predetermined intervals inside the housing 21 of the mark emission unit 20. The laser pointers 22 may be commercially available general-purpose products or may be manufactured specifically for this system, but all four laser pointers 22 emit parallel laser beams. The laser beams emitted by these four laser pointers 22 are adjusted to be parallel to each other at a predetermined interval (center-to-center distance). Since the laser beams emitted from the four laser pointers 22 are parallel to one another, the intervals between the laser beams remain constant regardless of the distance from the mark emitting unit 20. Therefore, when the laser light emitted by the mark emitting unit 20 is irradiated from a direction perpendicular to the wall W (the normal direction of the wall W), the spacing between the marks 101 formed on the wall W matches the spacing between the laser lights. On the other hand, when the laser light emitted by the mark emitting unit 20 is irradiated from an oblique direction other than perpendicular to the wall W, the interval between the marks 101 formed on the wall W changes depending on the incident angle of the laser light with respect to the wall W.

[0025] Here, a case where the laser light is irradiated from an angle other than the normal direction of the wall W will be considered. Situation 1: When wall W is tilted left or right relative to the laser irradiation direction. In this case, the marks 101 closer to the mark emission part are imaged with a larger distance between them, and the marks 101 farther from the mark emission part are imaged with a smaller distance between them. For example, when imaged with a CMOS sensor, the number of pixels between the marks 101 closer to the mark emission part is larger, and the number of pixels between the marks 101 farther from the mark emission part is smaller.

[0026] Situation 2: When the wall W is tilted vertically relative to the laser irradiation direction. The marks 101 are captured with a larger gap between them on the side closer to the mark emission part, and a smaller gap between them on the side farther from the mark emission part. For example, when captured with a CMOS sensor, the number of pixels between the marks 101 on the side closer to the mark emission part is larger, and the number of pixels between the marks 101 on the side farther from the mark emission part is smaller.

[0027] Considering the above two situations and the fact that buildings are usually constructed perpendicular to the ground and that when wall W is observed from a direction other than the normal direction, wall W is observed tilted left-right and / or up-down, the following conclusion can be drawn. That is, it is preferable that the laser light be irradiated at at least four points, and that the marks 101 be arranged along the left-right and up-down directions. It is also more preferable that the marks 101 be arranged so as to form the four corners of a square or rectangle. This arrangement reduces the computational load, significantly reducing the computational processing load compared to conventional structured light methods. This makes it possible to use the method in AGVs, drones, cleaning robots, and other applications where real-time processing is essential.

[0028] The distance and angle are calculated from the interval between the marks 101, but the size and distortion of the shape of each mark 101 may also be used. For example, the smaller the size of the mark 101 that is imaged, the farther the distance to that mark 101 is, and if the mark 101 is irradiated in a circular shape and is imaged as a circle, it is in the normal direction of the wall W, but if it is imaged as an ellipse, it is clear that the laser is being irradiated from a direction other than the normal to the wall W. Furthermore, the calculation unit 50 may perform calculations based on the above information, and the control unit 60 may control the moving body 10 to move in the normal direction of the wall W (irradiation target) based on the calculation results so that the laser light emitted by the mark emitting unit 20 is emitted in the normal direction of the wall W (irradiation target). This further reduces the subsequent calculation processing load, and by performing measurement again in this state, it is possible to perform measurement with higher accuracy.

[0029] The photographing unit 30 photographs four marks 101 formed by the laser light emitted from the mark emitting unit 20 and irradiated onto the wall W, which is the measurement object. In this embodiment, the mark emitting unit 20 and the photographing unit 30 are both positioned facing forward of the moving body 10 so as to emit laser light in the main traveling direction of the moving body 10 and photograph it.

[0030] The GPS antenna 40 receives radio waves from GPS satellites of the GPS (Global Positioning System). Note that if it is not necessary to obtain location information using GPS, the GPS antenna 40 may be omitted. Note that although the widely used GPS is exemplified here, other satellite positioning systems such as the QZSS (Quasi-Zenith Satellite System) may also be used, and various GNSS (Global Navigation Satellite Systems) can be applied as appropriate.

[0031] The calculation unit 50 calculates the relative positional relationship between the photographing unit 30 and the mark 101, that is, the relative positional relationship between the photographing unit 30 and the wall W on which the mark 101 is formed, using an image including the mark 101 photographed by the photographing unit 30. Here, the relative positional relationship refers to, for example, the distance to the position of the wall W based on the position of the photographing unit 30, the direction in which the normal to the wall W faces, etc. The method used by the calculation unit 50 to calculate the relative positional relationship between the photographing unit 30 and the mark 101 using the photographed image of the mark 101 can be the method described in Hideyuki Tanaka, "Fundamentals and Latest Trends of AR Marker Technology," Journal of the Institute of Electrical, Information and Communication Engineers, Vol. 97, No. 8, 2014, pp. 734-740.

[0032] Furthermore, the calculation unit 50 can calculate the relative positional relationship between the marks 101 projected at a plurality of different positions and the image capturing unit 30 while moving the mobile object 10 or rotating it on the spot, i.e., while the mobile object 10 is moving, in association with the movement of the mobile object 10. Through this calculation, the calculation unit 50 can create map data (mapping) about the environment surrounding the mobile object 10. Furthermore, during mapping, location information calculated from a GPS antenna can also be added, making it possible to clarify the location for which the mapping data is being generated.

[0033] The control unit 60 comprehensively controls various operations of the measurement system 1. The control unit 60 also controls the driving of the moving body 10 in consideration of the relative positional relationship with an obstacle such as a wall W calculated by the calculation unit 50. In addition, if mapping data has been acquired, the control unit 60 also uses the mapping data to control the driving.

[0034] The calculation unit 50 and control unit 60 of this embodiment are configured by installing a computer program on a computer. More specifically, the calculation unit 50 and control unit 60 of this embodiment are configured by installing an application program (measurement program) for the measurement system of the present invention on a computer used to control the measurement system 1. The computer used to control the measurement system 1 may be a general-purpose smartphone or tablet terminal, a laptop computer, or a dedicated computer specialized for controlling the measurement system 1. The computer referred to in this invention refers to an information processing device equipped with a control unit, a storage device, etc.

[0035] In the present embodiment, the calculation unit 50 and the control unit 60 are mounted on the mobile object 10, but for example, the calculation unit 50 and the control unit 60 may be provided on a server or the like installed at a location away from the mobile object 10. In this case, information from multiple mobile objects 10 can be integrated to more appropriately control the operation of each mobile object 10. Note that the calculation unit 50 may be mounted on the mobile object 10, and the control unit 60 may be provided on a server.

[0036] The driving unit 70 is controlled by the control unit 60 to drive the moving body 10. The driving unit 70 includes the wheels 11, a motor that generates driving force, a steering device, and the like.

[0037] Next, a measurement method using the measurement system 1 will be described. FIG. 4 is a flowchart showing the flow of operations of the measurement system 1.

[0038] In step (hereinafter simply referred to as S) 11, the mark emitting section 20 emits four laser beams. In S12, the photographing unit 30 photographs the wall W on which the mark 101 is formed.

[0039] In S13, the calculation unit 50 calculates the relative positional relationship between the mark 101 and the photographing unit 30. In S14, the control unit 60 determines whether or not to perform mapping. This determination can be made based on the settings registered in advance by the user. If mapping is to be performed, the process proceeds to S15; if mapping is not to be performed, the measurement operation ends.

[0040] In S15, the control unit 60 controls the driving unit 70 to change the orientation and position of the moving body 10, and changes the position at which the mark emitting unit 20 irradiates the laser light. In S16, the mark emitting unit 20 emits four laser beams. In S17, the photographing unit 30 photographs the wall W on which the mark 101 is formed.

[0041] In S18, the calculation unit 50 calculates the relative positional relationship between the mark 101 and the photographing unit 30. The information about the position calculated in this step, together with information about the change in the irradiation position caused by moving the moving body 10 in S15, is added to the information about the position calculated previously to form mapping data. In S19, the control unit 60 determines whether or not mapping has been completed. If mapping has been completed, the measurement operation is terminated, and if mapping is to be continued, the process returns to S15. The above steps are executed by a computer under an application program for the measurement system.

[0042] As described above, the measurement system 1 of the first embodiment is highly convenient because it is possible to measure the position or attitude without installing a physical marker. Also, it is possible to detect obstacles and the like from the moving body 10 while moving, allowing for more appropriate automatic driving of the moving body 10. Furthermore, by performing mapping, it is possible to grasp the surrounding conditions in advance, allowing for more appropriate automatic driving of the moving body 10.

[0043] (Second embodiment) FIG. 5 is a diagram showing an outline of a measurement system according to the second embodiment. The measurement system of the second embodiment is similar to that of the first embodiment, except that the shape of the marker 100B formed by the laser light emitted by the mark emitting unit 20 is different from that of the marker 100 of the first embodiment. Therefore, parts that perform the same functions as those in the first embodiment described above are given the same reference numerals, and duplicated explanations will be omitted as appropriate.

[0044] The marker 100B of the second embodiment differs from the first embodiment in that an identification mark 102 is further formed in the area surrounded by the four marks 101. The identification mark 102 is a pattern graphic (graphic for identification) that displays unique information by its pattern, with a specific meaning associated with the pattern of the mark. For example, the identification mark 102 has a unique number, alphabet, or the like associated with each different pattern. The identification mark 102 can function similarly to a two-dimensional barcode. Note that, while it is desirable for the positions of the laser beams of the identification mark 102 to be closely spaced from each other as shown in FIG. 5, they may also be spaced apart. Furthermore, the irradiation shape of each of the identification marks 102 is not limited to a square as shown in the figure, and may be a circle, etc.

[0045] The identification mark 102 is formed by a laser beam emitted from the mark emission unit 20, similar to the mark 101. To be able to emit such a laser beam, the mark emission unit 20 of the second embodiment has more laser pointers 22 therein than in the first embodiment. In the example of FIG. 5, the mark emission unit 20 has four laser pointers 22 for the mark 101 and 36 laser pointers 22 for the identification mark 102, for a total of 40 laser pointers 22. By switching each laser pointer 22 for the identification mark 102 between emitting and not emitting light, many patterns can be created as the identification mark 102.

[0046] By providing the identification mark 102, it becomes possible to determine which moving body 10 has emitted the marker 100B in a situation where multiple moving bodies 10 are operating. Therefore, it is possible to accurately control multiple moving bodies 10 in the same location.

[0047] As described above, according to the second embodiment, since the identification mark 102 is provided, it is possible to easily determine from which moving body 10 the marker 100B is emitted.

[0048] (Variations) The present invention is not limited to the above-described embodiment, and various modifications and variations are possible, and these are also within the scope of the present invention.

[0049] (1) In each embodiment, the mark emitting unit 20 has been described as emitting parallel laser beams at a predetermined interval in a parallel state. This is not limiting, and for example, the laser beams may travel in different directions, each at a slight angle from the parallel state. In this case, the traveling direction of each laser beam may be known in advance, and the traveling direction (angle) of each laser beam may be corrected by calculation.

[0050] (2) In each embodiment, an example has been described in which the moving body 10 is provided with one combination of the mark emitting unit 20 and the photographing unit 30. However, this is not limiting, and the moving body 10 may be provided with multiple combinations of the mark emitting unit 20 and the photographing unit 30. Furthermore, the moving body 10 may be provided with multiple units of at least one of the mark emitting unit 20, the photographing unit 30, and the calculation unit 50.

[0051] (3) In each embodiment, an example in which the mark emitting unit 20, the photographing unit 30, and the calculation unit 50 are provided on the moving object 10 has been described. However, this is not limiting. For example, the mark emitting unit 20, the photographing unit 30, and the calculation unit 50 may be provided on a fixed object such as a ceiling or wall. In this case, the height of luggage passing through the monitoring position can be measured, the number of layers of luggage can be estimated, and the size of the moving object that has passed can be measured. In this case, the mark emitting unit 20 may be provided with an irradiation direction variable mechanism so that the irradiation position can be changed, thereby tracking luggage, moving objects, etc. Alternatively, the mark emitting unit 20 may be provided on a fixed object, and the photographing unit 30 and the calculation unit 50 may be provided on the moving object. Each component may be provided on either a fixed object or a moving object.

[0052] (4) In the second embodiment, an example has been described in which the identification mark 102 is formed using the laser pointer 22. However, the present invention is not limited to this, and for example, a hologram may be projected from the mark emission unit 20.

[0053] (5) In each embodiment, a configuration in which four marks 101 can be formed has been exemplified. However, the present invention is not limited to this, and the number of emitted marks 101 may be, for example, two, three, or five or more. When the number of emitted marks 101 is two, distance measurement is possible, and when the number is three or more, distance and tilt (posture) of the irradiated surface can be measured.

[0054] (6) In each embodiment, the mark emitting unit 20 and the photographing unit 30 are arranged facing forward of the moving body 10. However, the present invention is not limited to this. For example, the mark emitting unit 20 and the photographing unit 30 may face in another direction, or may be attached to the moving body 10 so that the emitting direction of the laser light and the photographing direction can be freely changed. [Explanation of symbols]

[0055] 1. Measurement System 10 Mobile 11 wheels 20 Mark emission part 21. Cabinet 22 Laser Pointer 30 Photography Department 40 GPS antenna 50 Arithmetic section 60 Control Unit 70 Drive unit 100, 100B markers 101 marks 102 Identification Mark

Claims

1. A mark emitting device having a mark emitting unit that emits a plurality of laser beams, the mark emitting unit further emits an identification mark which is a pattern graphic that displays information by a pattern in addition to the plurality of marks formed by the laser light; A mark emission device characterized by:

2. 2. The mark emission device according to claim 1, the mark emitting unit emits parallel laser beams in a state parallel to each other at a predetermined interval; A mark emission device characterized by:

3. 3. The mark emission device according to claim 1, the mark emitting unit emits three or more laser beams; A mark emission device characterized by:

4. 4. A moving body provided with the mark emitting device according to claim 1.

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