Distance Measurement System

Abstract

To provide a distance measuring system with which it is possible to detect the attached posture of a distance measuring device attached to a body unit, without using an apparatus for posture detection such as an inclination sensor or a level gauge.SOLUTION: A conveyance system 50 comprises a body unit 31, a TOF sensor 20, and an attached posture detection device 10. The TOF sensor 20 includes a lighting unit 21 for irradiating a floor surface FL with light, an imaging element 23 for detecting light radiated from the lighting unit 21, a distance information acquisition unit 11 for acquiring distance information to reference points P1, P2 on the floor surface FL in accordance with a phase difference between the received light wave and projected light wave of light detected by the imaging element 23, and an angle information acquisition unit 12 for acquiring angle information to the reference points P1, P2, the TOF sensor being mounted to the body unit 31. The attached posture detection unit 14 detects the attached posture of the TOF sensor 20 to the floor surface FL on the basis of the distance information and angle information acquired by the distance information acquisition unit 11 and the angle information acquisition unit 12.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a distance measurement system including a distance measurement device that measures the distance to an object based on the phase difference between a projected light wave irradiated onto the object and a received light wave. [Background technology]

[0002] In recent years, for example, a TOF (Time-of-Flight) sensor has been used that measures the distance to an object by receiving reflected light of light emitted from an LED (Light Emitting Diode) as a light source toward the object. For example, Patent Document 1 discloses an object detection device that includes an emission means for emitting a beam in order to correct a deviation in the projection direction of a laser beam emitted by the object detection device, a receiving means for receiving a reflected beam formed when the beam emitted by the emission means hits an object and is reflected, a discrimination means for discriminating whether the object that reflected the reflected beam received by the receiving means is a road surface, a measurement means for measuring the distance to the reflection position on the road surface based on the reflected beam received by the receiving means, a calculation means for calculating the inclination angle of the road surface based on the distance to the reflection position on the road surface measured by the measurement means, and a control means for controlling the emission angle of the beam based on the inclination angle of the road surface calculated by the calculation means. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-276023 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above-described conventional object detection device has the following problems. That is, the object detection device disclosed in the above publication is used as a laser radar mounted on an automobile, and calculates the inclination angle of the road surface based on the distance to the reflection position of the beam emitted from the emitting means when it hits the road surface and is reflected, and adjusts the emission angle of the beam.

[0005] However, with this configuration, although it is possible to adjust the direction of the laser projection in accordance with the deviation of the laser optical axis direction distorted by a collision or the like, it is not possible to recognize the installation posture of the laser radar. Therefore, in order to recognize the mounting orientation of the laser radar, a separate device for detecting the orientation, such as an inclination sensor or a level, is required.

[0006] An object of the present invention is to provide a distance measurement system that can detect the mounting posture of a distance measurement device attached to a main body without using posture detection equipment such as an inclination sensor or a spirit level. [Means for solving the problem]

[0007] A distance measurement system according to a first aspect of the present invention is a distance measurement system including a distance measurement device that measures the distance to an object based on the phase difference between a projected light wave and a received light wave irradiated onto the object, and includes a main body, the distance measurement device, and an installation attitude detection unit. The distance measurement device has an illumination unit that irradiates light onto a predetermined reference surface, a detection unit that detects the light irradiated from the illumination unit, a distance information acquisition unit that acquires distance information to a reference point on the reference surface based on the phase difference between the projected light wave and the received light wave of the light detected by the detection unit, and an angle information acquisition unit that acquires angle information to the reference point, and is attached to the main body. The installation attitude detection unit detects the installation attitude of the distance measurement device relative to the reference surface based on the distance information and angle information acquired by the distance information acquisition unit and the angle information acquisition unit.

[0008] Here, for example, in order to detect the mounting posture of a distance measuring device attached to a specified piece of equipment such as a conveying device, the mounting posture of the distance measuring device relative to a reference surface is detected using distance information and angle information measured by the distance measuring device. Here, the distance measurement device can be, for example, a TOF (Time-of-Flight) sensor, LiDAR (Light Detection And Ranging), or SC (Structural Camera), which is capable of acquiring distance information to a reference point on a reference plane and has angle information.

[0009] The mounting posture of the distance measuring device means, for example, the tilt angle of the distance measuring device relative to a reference plane, the distance from the reference plane, the rotation angle relative to the reference plane, and the like. A reference plane is, for example, a flat surface such as a floor surface on which a specified device is installed or a wall surface arranged along the vertical direction, and a reference point on the reference plane means, for example, a specified point on the floor surface or wall surface.

[0010] The light emitted from the illumination unit includes, for example, light in the broad sense (ultraviolet light, visible light, infrared light) and the like. The distance information acquisition unit may be configured to detect the reflection of light and calculate the distance information, or may be configured to acquire the distance information from, for example, a distance sensor or the like provided as an external device. The mounting attitude detection unit may be provided, for example, inside the distance measurement device, or may be provided separately from the distance measurement device.

[0011] Furthermore, the predetermined object on which the distance measuring device is attached may be, for example, a vehicle such as a conveyance device or a passenger car, or may be an indoor wall surface, a ceiling surface, an outdoor support, or the like. This makes it possible to detect the mounting orientation of the distance measurement device relative to a reference surface such as a floor surface using the results (distance information and angle information) measured or acquired by the distance measurement device. As a result, the mounting orientation of the distance measuring device attached to various devices can be detected without using any equipment for detecting the orientation, such as an inclination sensor or a level.

[0012] The distance measurement system of the second invention is the distance measurement system of the first invention, wherein the main body has wheels that can run on a reference surface, a drive unit that drives the wheels to rotate, and a drive control unit that controls the drive unit. This makes it possible to detect the mounting posture of a distance measuring device in a system configuration in which the distance measuring device is attached to a conveying device that can run on a reference surface by rotating its wheels, using distance and angle information measured or acquired by the distance measuring device itself.

[0013] A distance measurement system according to a third aspect of the present invention is the distance measurement system according to the second aspect of the present invention, wherein the drive control unit controls the drive unit to drive the wheels to rotate, and moves to a predetermined return position. This allows, in a system configuration in which a distance measuring device is attached to a transport device that can run on a reference surface by rotating its wheels, for example, to be controlled so that when use is finished, the device automatically returns to a predetermined return position and waits.

[0014] A distance measurement system according to a fourth aspect of the present invention is the distance measurement system according to the third aspect of the present invention, further comprising a charging station that is provided at a return location and to which a part of the main body is connected. This allows a system configuration in which a distance measuring device is attached to a transport device that can rotate its wheels and run on a reference surface to control it to return to a charging station located at a predetermined destination position and wait there.

[0015] A distance measurement system according to a fifth aspect of the present invention is the distance measurement system according to the fourth aspect of the present invention, wherein the main body has a secondary battery that supplies power to the drive unit, and the charging station has a charging device that charges the secondary battery.

[0016] This means that in a system configuration in which a distance measuring device is attached to a conveying device that can run on a reference surface by rotating its wheels, for example, after use, the device can be connected to a charging station to charge the secondary battery provided in the main body. Therefore, the secondary battery is always in a charged state, and power can be stably supplied to the drive unit that drives the wheels.

[0017] A distance measurement system according to a sixth aspect of the present invention is a distance measurement system according to any one of the third to fifth aspects of the present invention, wherein the distance information acquisition unit acquires distance information relative to a reference point acquired at a return position. As a result, by acquiring distance information used to detect the mounting attitude of the distance measurement device at a specific position (return position), it is possible to perform more stable and accurate detection of the mounting attitude.

[0018] A distance measurement system according to a seventh aspect of the present invention is a distance measurement system according to the sixth aspect of the present invention, in which the mounting attitude detection unit detects the mounting attitude using distance information and angle information relative to a reference plane acquired at the return position. This allows the detection of the mounting attitude of the distance measuring device at a specific position (return position), thereby making it possible to detect the mounting attitude more stably and accurately.

[0019] The distance measurement system of the eighth invention is a distance measurement system of any one of the first to seventh inventions, wherein the mounting attitude detection unit detects at least one of the inclination angle of the distance measurement device relative to a reference plane, the distance from the reference plane, and the rotation angle relative to the reference plane as the mounting attitude. This makes it possible to detect at least one of the tilt angle, distance, and rotation angle of the distance measuring device relative to the reference plane as the mounting attitude.

[0020] A distance measurement system according to a ninth aspect of the present invention is a distance measurement system according to any one of the first to eighth aspects of the present invention, in which the mounting attitude detection unit detects the mounting attitude using distance information and angle information to two reference points on the reference plane. This makes it possible to detect the mounting orientation of the distance measuring device described above, for example, using information on the distance and angle relative to two reference points on a reference surface such as a floor surface.

[0021] A distance measurement system according to a tenth aspect of the present invention is a distance measurement system according to any one of the first to ninth aspects of the present invention, wherein the distance measurement device further includes a distance image generation unit that generates a distance image including a reference plane based on the results acquired by the distance information acquisition unit and the angle information acquisition unit, and further includes a distance image acquisition unit that acquires the distance image from the distance image generation unit. This allows each pixel included in the acquired distance image to have distance information and angle information, making it possible to detect the mounting orientation of the distance measuring device using a specific pixel as a reference point.

[0022] The distance measurement system of the 11th invention is the distance measurement system of the 10th invention, wherein the mounting attitude detection unit detects the mounting attitude of the distance measurement device using a first distance to a first reference point on the reference plane at a first pixel included in the distance image acquired by the distance image acquisition unit and a first angle relative to the reference plane, and a second distance to a second reference point on the reference plane at a second pixel different from the first pixel and a second angle relative to the reference plane. This allows the mounting posture of the distance measuring device to be detected using a first distance to a first reference point and a first angle relative to the reference plane, which are information held by a first pixel included in the distance image, and a second distance to a second reference point and a second angle relative to the reference plane, which are information held by a second pixel included in the distance image.

[0023] The distance measurement system of the 12th invention is a distance measurement system of the 10th or 11th invention, in which the mounting attitude detection unit detects rotation relative to a reference plane as the mounting attitude of the distance measurement device using a first angle relative to the illumination axis of light irradiated from the illumination unit at a first pixel included in the distance image acquired by the distance image acquisition unit, and a second angle relative to the illumination axis of light irradiated from the illumination unit at a second pixel different from the first pixel. This makes it possible to detect the mounting posture of the distance measuring device (whether it is rotated relative to the reference plane) using a first angle relative to the illumination axis of light emitted from the lighting unit at a first pixel included in the distance image and a second angle relative to the illumination axis at another second pixel.

[0024] The distance measurement system of the 13th invention is a distance measurement system of any one of the 10th to 12th inventions, in which the mounting attitude detection unit detects the rotation of the mounting attitude of the distance measurement device based on whether the position of a pixel in the distance image acquired by the distance image acquisition unit, at which the distance to the reference plane is the same, has moved from a predetermined reference position. This makes it possible to detect whether the mounting posture of the distance measuring device has rotated depending on whether the position of the pixel at which the distance to the reference surface in the distance image acquired by the distance image acquisition unit is the same has moved.

[0025] The distance measurement system of the 14th invention is a distance measurement system of any one of the 10th to 13th inventions, in which the mounting attitude detection unit detects the rotation angle of the mounting attitude of the distance measurement device based on how many degrees the position of a pixel at which the distance to the reference plane in the distance image acquired by the distance image acquisition unit is the same is rotated from a predetermined reference position. This makes it possible to detect the rotation angle of the pixel position at which the distance to the reference surface is the same in the distance image acquired by the distance image acquisition unit as the rotation angle of the mounting attitude of the distance measurement device.

[0026] The distance measurement system of the 15th invention is a distance measurement system of any one of the first to fourteenth inventions, and further includes a correction feasibility determination unit that determines whether or not to correct the measurement result of the distance measurement device based on the detection result of the mounting attitude detection unit.

[0027] This makes it possible to determine whether or not to correct the distance information measured by the distance measurement device depending on whether or not the mounting posture (mounting angle, rotation angle, etc.) of the distance measurement device is within a predetermined allowable range. Therefore, for example, in a situation where the distance measurement device is tilted so much that distance correction is not possible, measures can be taken such as informing the user without performing distance correction.

[0028] The distance measurement system of the 16th invention is a distance measurement system of any one of the 1st to 15th inventions, further comprising a memory unit that stores information regarding the mounting posture of the distance measurement device detected by the mounting posture detection unit. This allows information about the mounting attitude of the distance measuring device, such as the mounting angle and rotation angle, to be stored, and this information about the mounting attitude can be used to correct the distance information measured by the distance measuring device.

[0029] A distance measurement system according to a seventeenth aspect of the present invention is the distance measurement system according to any one of the first to sixteenth aspects of the present invention, wherein the reference plane is a floor surface. This makes it possible to detect the mounting orientation of the distance measuring device described above by using the floor surface as a reference plane and setting a reference point on the floor surface.

[0030] The distance measurement system of the 18th invention is a distance measurement system of any one of the 1st to 17th inventions, wherein the distance measurement device is any one of a TOF (Time-of-Flight) sensor, a LiDAR (Light Detection And Ranging), or an SC (Structural Camera). This makes it possible to detect the mounting attitude using distance information and angle information measured by various distance measurement devices such as a TOF sensor, LiDAR, and SC. [Effects of the Invention]

[0031] According to the distance measurement system of the present invention, the mounting orientation of the distance measurement device attached to the main body can be detected without using any orientation detection equipment such as an inclination sensor or a level. [Brief explanation of the drawings]

[0032] [Figure 1] 1 is a perspective view showing the configuration of a transport system in which a transport device is equipped with a TOF sensor equipped with an attachment attitude detection device according to an embodiment of the present invention. [Figure 2] (a) is a conceptual diagram showing the configuration of the transport system when the transport device in Figure 1 is set in the DOCK. (b) is a top view of (a). [Figure 3] A conceptual diagram showing the polar coordinates, Cartesian coordinates, and Cartesian coordinate system parallel to the floor of the TOF sensor attached to the transport device in Figure 2. [Figure 4] FIG. 2 is a control block diagram of a TOF sensor and the like included in the transport system of FIG. 1. [Figure 5] FIG. 2 is a diagram explaining the principle by which the TOF sensor in FIG. 1 calculates the distance to an object using the TOF method. [Figure 6] FIG. 5 is a control block diagram showing the configuration of an attachment attitude detection device included in the TOF sensor of FIG. 4. [Figure 7] 7A and 7B are diagrams for explaining the principle of detecting the mounting angle and mounting height of the TOF sensor in the mounting attitude detection device of FIG. 6. [Figure 8] 7A and 7B are diagrams for explaining the principle of detecting the rotation angle of the TOF sensor in the mounting attitude detection device of FIG. 6. [Figure 9] 7A and 7B are diagrams for explaining the principle of detecting the rotation angle of the TOF sensor in the mounting attitude detection device of FIG. 6. [Figure 10] 7A and 7B are diagrams for explaining the principle of detecting the rotation angle of the TOF sensor in the mounting attitude detection device of FIG. 6; [Figure 11] 7A and 7B are diagrams illustrating the principle of detecting the mounting angle and mounting height when the TOF sensor is rotated in the mounting attitude detection device of FIG. 6; [Figure 12] 7 is a flowchart showing a process flow for detecting the mounting angle and mounting height of the TOF sensor in the mounting attitude detection device of FIG. 6; [Figure 13] 7 is a flowchart showing the flow of a process for detecting the rotation angle of the TOF sensor in the mounting attitude detection device of FIG. 6; [Figure 14]10 is a flowchart showing the flow of processing performed when the transport device in FIG. 1 returns to the DOCK. [Figure 15] 10 is a diagram showing a state in which a TOF sensor including an installation posture detection device according to another embodiment of the present invention is installed on a wall in a room as a monitoring device. FIG. [Figure 16] FIG. 10 is a control block diagram showing the configuration of a conveyance system including an attachment attitude detection device according to still another embodiment of the present invention. [Figure 17] FIG. 10 is a control block diagram showing the configuration of a conveying system including a conveying device including a mounting attitude detection device according to still another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0033] The following describes a conveying system (distance measurement system) 50 equipped with a conveying device (predetermined object) 30 equipped with a TOF sensor (distance measurement device) 20 including an installation posture detection device 10 according to one embodiment of the present invention, using Figures 1 to 14. (1) Transport System 50 The conveying system (distance measurement system) 50 is a system that controls the conveying device 30 shown in Figure 1 so that it automatically performs the desired conveying task, and is equipped with the conveying device 30, a TOF sensor (distance measurement device) 20 attached to the conveying device 30, an attachment attitude detection device 10 provided within the TOF sensor 20, and a DOCK (return position, charging station) 40 (see Figure 2(a) etc.).

[0034] In the transport system 50, the transport device 30 automatically travels while recognizing obstacles and the like in the traveling direction using the TOF sensor 20, and performs a predetermined transport operation. Then, for example, when the transport operation is completed or when the remaining charge of the transport device 30 is low, the transport device 30 returns to a predetermined waiting position (return position) as shown in Figures 2(a) and 2(b). The control unit 100 controls the robot to return to DOCK40, which is installed at the DOCK40 location.

[0035] The mounting posture detection device 10 is provided inside the TOF sensor 20, and detects the mounting posture of the TOF sensor 20 relative to the floor surface FL using distance information and angle information to reference points P1, P2 (see Figure 7, etc.) on the floor surface FL detected by the TOF sensor 20. The detailed configuration of the mounting posture detection device 10 will be described later. As shown in FIG. 1 etc., the TOF sensor 20 is attached to the upper surface of the main body 31 of the conveying device 30, and detects information such as the distance to obstacles in the traveling direction of the conveying device 30 and to the luggage being conveyed.

[0036] The detailed configuration of the TOF sensor 20 will be described later. The transport device (predetermined object) 30 is an example of a predetermined object to which the TOF sensor 20 is attached, and is, for example, an automatic transport device such as an AGV (Automatic Guided Vehicle) or an AMR (Autonomous Mobile Robot) that is controlled by a predetermined travel program. The transport device 30 performs transport work, for example, in a factory, a warehouse, or the like, either unmanned or manned.

[0037] As shown in Figures 1 and 4, the conveying device (specified object) 30 includes a main body 31, a drive unit 32, wheels 32a, a fork 33, a drive control unit 34, a charging terminal 35, and a secondary battery 36. The main body 31 is, for example, a substantially cylindrical housing, and the TOF sensor 20 is attached to the upper surface thereof. In addition, a plurality of wheels 32a are provided on the lower part of the main body 31, which are rotatably attached and move the transport device 30 in a desired direction.

[0038] The drive unit 32 is, for example, an electric motor, and drives at least one of a plurality of wheels 32a attached to the lower part of the main body 31 to rotate, thereby causing the transport device 30 to travel in a desired direction. In this embodiment, three wheels 32a are provided on the lower part of the main body 31, and at least one of them is rotationally driven by the drive unit 32. In addition, at least one of the wheels 32a is provided as a steering wheel that determines the traveling direction of the transport device 30.

[0039] The forks 33 are provided in front of the main body 31 and are used to carry loads during transport work. The forks are controlled by a transport control unit (not shown) provided in the transport device 30 to raise and lower the forks, change their tilt angle, and so on. The drive control unit 34 controls the rotation speed and direction of the drive unit 32 that rotates the multiple wheels 32a, allowing the conveyance device 30 to move in a desired direction at a desired speed to perform conveyance work.

[0040] 1, the charging terminal 35 is provided on the rear side (opposite side from the fork 33) of the main body 31. Then, as shown in FIGS. 2(a) and 2(b), when the transport device 30 is connected to the DOCK 40, the charging terminal 35 is connected to a connection part 41 on the DOCK 40 side, and power is supplied to the transport device 30 from a power supply part (charging device) 42. 1, the secondary battery 36 is provided inside the main body 31 of the transport device 30. When the transport device 30 is connected to the DOCK 40, the secondary battery 36 is repeatedly charged by power supplied from the DOCK 40 via the charging terminal 35. The secondary battery 36 then supplies the stored power to the drive unit 32.

[0041] As shown in Figures 2(a) and 2(b), DOCK 40 is installed at a predetermined waiting position (return position) where the transport device 40 returns after completing its transport work, and the transport device 30 is connected to DOCK 40 at this waiting position, and the secondary battery 36 installed therein is charged. Furthermore, on the front side of the transport device 30 connected to the DOCK 40, as shown in FIGS. 2(a) and 2(b), a mark M drawn on the floor surface FL is placed.

[0042] The mark M has a line segment L2 that is approximately parallel to the front of the transport device 30 on which the fork 33 is provided. The line segment L2 is disposed approximately perpendicular to the line connecting the DOCK 40 and the transport device 30 connected to the DOCK 40. This allows the mounting posture detection device 10 to detect the mounting posture of the TOF sensor 20 attached to the transport device 30 with the line segment L2 of the mark M as a reference. In this embodiment, an example will be given in which the transport device 30 detects the mounting posture of the TOF sensor 20, determines whether correction is possible, and performs correction processing of the measured distance information while connected to the DOCK 40; however, processing such as detecting the mounting posture of the TOF sensor 20 may also be performed while the transport device 30 is not connected to the DOCK 30.

[0043] (2) TOF sensor 20 As shown in FIG. 3, the TOF sensor (distance measurement device) 20 is attached to the upper surface of the main body 31 of the transport device 30, facing downward from the horizontal plane. The TOF sensor 20 converts the polar coordinate system into a Cartesian coordinate system (the TOF optical axis coordinate system (X ) shown by the solid line in FIG. 3) using a preset angle table and the measured distance value. T ,Y T ,Z T Furthermore, the TOF sensor 20 performs a first coordinate transformation to convert the TOF optical axis coordinate system (X T ,Y T ,Z T ) on the Cartesian coordinate system (shown by the dashed lines in Figure 3) parallel to the floor surface FL. TH ,Y TH ,Z TH Furthermore, the TOF sensor 20 performs a second coordinate transformation to convert the rotation angle of the TOF sensor 20 obtained by a rotation angle detection process described later into a Cartesian coordinate system (X TH ,Y TH ,Z TH ) in the Cartesian coordinate system (X A ,Y A ,Z A ) and perform a third coordinate transformation to match

[0044] After the third coordinate transformation is performed, the transport device 30 (TOF sensor 20) is A The axis is arranged so as to be perpendicular to the line segment L2 of the mark M (see FIGS. 2(a) and 2(b)). The rotation angle of the TOF sensor 20 is an angle indicating a positional deviation in a rotation direction around the irradiation axis of the light emitted from the illumination unit 21.

[0045] As shown in FIG. 4, the TOF sensor 20 includes an illumination unit 21, a light receiving lens 22, an imaging element 23, a control unit 24, a storage unit 25, and the mounting attitude detection device 10. The lighting unit 21 has, for example, an LED, and irradiates light L1 having a desired wavelength onto an object such as a cargo or a floor surface FL. The lighting unit 21 is provided with a light projection lens (not shown) that guides the light L1 irradiated from the LED toward the object.

[0046] The light receiving lens 22 is provided to receive light that is irradiated from the illumination unit 21 onto the object and reflected by the object, and to guide the light to the imaging element 23. The image sensor 23 has a plurality of pixels, and receives the reflected light received by the light receiving lens 22 at each of the plurality of pixels, and transmits photoelectrically converted electrical signals to the control unit 24. The electrical signals corresponding to the amount of received reflected light detected by the image sensor 23 are used by the control unit 24 to calculate distance information.

[0047] The control unit 24 reads various control programs stored in the storage unit 25 and controls the illumination unit 21 that irradiates the object with light. The control unit 24 also adjusts the light emitted by the illumination unit 21 and the exposure time of the image sensor 23 that detects the amount of reflection of the light irradiated from the illumination unit 21, for example, depending on the distance to the object. Specifically, the control unit 24 adjusts the exposure time to be shorter when the distance to the object is short, and adjusts the exposure time to be longer when the distance to the object is far.

[0048] As shown in FIG. 4, the control unit 24 includes a distance information calculation unit 24a, an angle information acquisition unit 24b, a distance image generation unit 24c, and a distance correction processing unit 24d. The distance information calculation unit 24a calculates distance information to the object for each pixel based on the electrical signal corresponding to each pixel received from the image sensor 23. Here, the calculation of distance information to an object by the TOF sensor 20 of this embodiment will be described below with reference to FIG.

[0049] That is, in this embodiment, using the so-called TOF (Time of Flight) method, the distance information calculation unit 24a calculates the distance to the target object based on the phase difference Φ (see Figure 4) between the AM-modulated constant-frequency projected light wave, such as a sine wave or rectangular wave, irradiated from the illumination unit 21 and the received light wave of the light received by the imaging element 23. Here, the phase difference Φ is expressed by the following relational expression (1).

[0050] Φ=atan(y / x) (1) (x=a2-a0, y=a3-a1, a0 to a3 are the amplitudes of the received light wave sampled four times at 90-degree intervals) The conversion formula from the phase difference Φ to the distance D is given by the following relational expression (2). D=(c / (2×fLED))×(Φ / 2π)+DOFFSET (2) (c is the speed of light (≒3×108 m / s), fLED is the modulation frequency of the LED light wave, and DOFFSET is the distance offset.) As a result, the distance information calculation unit 24a can easily calculate the distance to the object using the speed of light c by receiving the reflected light of the light irradiated from the illumination unit 21 and comparing the phase difference.

[0051] The angle information acquisition unit 24b acquires the angle (angle information) of each pixel constituting the image sensor 23 of the TOF sensor 20 with respect to the irradiation axis of light irradiated from the illumination unit 21. The angle information acquisition unit 24b can acquire, for example, angle information for each pixel stored in advance in the storage unit 25 as a table from the storage unit 25. Distance image generation unit 24c uses the distance information and angle information calculated and acquired by distance information calculation unit 24a and angle information acquisition unit 24b, respectively, to generate a distance image in which distance information and angle information are assigned to each pixel.

[0052] The distance correction processing unit 24d performs correction processing as necessary on the distance information calculated by the distance information calculation unit 24a based on the mounting posture (mounting angle, rotation angle, etc.) of the TOF sensor 20 detected by the mounting posture detection device 10 described later. The memory unit 25 stores, for example, various programs that control the operation of the TOF sensor 20, as well as distance information calculated by the distance information calculation unit 24a, angle information corresponding to each pixel that is stored in advance as a table, a distance image generated by the distance image generation unit 24c, and distance information corrected by the distance correction processing unit 24d.

[0053] (3) Mounting posture detection device 10 4, the mounting attitude detection device 10 according to this embodiment is provided in the TOF sensor 20, and detects the mounting attitude of the TOF sensor 20 itself using distance information and angle information to reference points P1 and P2 on the floor surface FL detected by the TOF sensor 20. As shown in FIG. 6, the mounting attitude detection device 10 includes a distance information acquisition unit 11, an angle information acquisition unit 12, a distance image acquisition unit 13, a mounting attitude detection unit 14, a correction feasibility determination unit 15, a storage unit 16, and a notification unit 17.

[0054] The distance information acquisition unit 11 acquires, from the control unit 24, information about the distance to the object calculated by the distance information calculation unit 24a. The angle information acquisition unit 12 acquires from the control unit 24 the angle information to the target object acquired by the angle information acquisition unit 24b. Distance image acquisition unit 13 acquires from control unit 24 the distance image generated by distance image generation unit 24c.

[0055] The mounting attitude detection unit 14 detects the mounting attitude of the TOF sensor 20 relative to the floor surface FL by using the distance information and angle information to the floor surface FL measured by the TOF sensor 20. More specifically, as shown in Fig. 6, the mounting attitude detection unit 14 has a mounting angle detection unit 14a, a mounting height detection unit 14b, and a rotation detection unit 14c. The mounting angle detection unit 14a detects information about the mounting angle of the TOF sensor 20 with respect to the floor surface FL as information about the mounting attitude. Specifically, the mounting angle detection unit 14a detects the mounting angle θa of the TOF sensor 20 with respect to the floor surface FL, which is attached to the transport device 30, using the measurement results (distance information d1, d2) to the two reference points P1, P2 and the angle information θ1, θ2 corresponding to each pixel of the image sensor 23.

[0056] The mounting height detection unit 14b detects information regarding the mounting height of the TOF sensor 20 from the floor surface FL. Specifically, the mounting height detection unit 14b detects the mounting height da of the TOF sensor 20 attached to the conveying device 30 from the floor surface FL using the measurement results (distance information d1, d2) to the two reference points P1, P2 and the angle information θ1, θ2 corresponding to each pixel of the image sensor 23.

[0057] Here, the detected mounting posture (mounting angle θa, mounting height da) is calculated using the results (d1, d2, θ1, θ2) of measuring the distances to any two reference points P1 and P2 on the floor surface FL, as shown in Figure 7. That is, da: The installation height of the TOF sensor from the floor surface FL (da is a line perpendicular to the floor surface FL at 90°), θa: the angle between the floor surface FL and the optical axis of the TOF sensor 20, θ1: angle of the first pixel of the TOF sensor 20 relative to the TOF center (sensor specifications), d1: the distance (measured value) from the first pixel of the TOF sensor 20 to the reference point P1 on the floor surface FL, θ2: angle of the second pixel of the TOF sensor 20 relative to the TOF center (sensor specifications), d2: distance from the second pixel of the TOF sensor 20 to the reference point P2 on the floor surface FL (measured value) Then, the following relation holds:

[0058] cos(θa)=da / d cos(θa-θ1)=da / d1 cos(θa-θ2)=da / d2 Therefore, the mounting height da is expressed by the following two equations using the mounting angle θa, distance information (d1, d2) to the reference points P1 and P2, and angle information (θ1, θ2).

[0059] da=d1cos(θa-θ1) ····(1) da=d2cos(θa-θ2) ····(2) Here, θ1 and θ2 are known values ​​determined by the sensor specifications, and d1 and d2 are values ​​obtained by measurement. Therefore, the mounting height da and mounting angle θa can be calculated from equations (1) and (2).

[0060] The rotation detector 14c detects information related to the rotation angle around the optical axis of the TOF sensor 20. Specifically, as shown in Fig. 8, the rotation detector 14c assumes that all pixels on a circle C centered on the central pixel P0 of the frame of the distance image generated by the distance image generator 24c of the TOF sensor 20 attached to the transport device 30 should have the same angle of view (e.g., θ1). Therefore, as shown in Fig. 9, the rotation detector 14c detects whether the TOF sensor 20 has rotated and calculates the rotation angle θb depending on whether the position of the pixel on the circle C centered on the image center of the frame image has moved.

[0061] That is, as shown in Fig. 10(a), the rotation angle θb detected by the rotation detection unit 14c indicates that the detected distances to pixels P3 and P4 that intersect with the horizontal line passing through the center pixel P0 (x0, y0) are the same when there is no rotation of the TOF sensor 20. On the other hand, when there is rotation of the TOF sensor 20, the pixels whose detected distances to pixels P3 and P4 are the same move by the amount of the rotation angle θb, as shown in Fig. 10(b).

[0062] As a result, the rotation angle θb of the TOF sensor 20 can be found from the presence or absence of a change in the positions of the pixels P3 and P4 that are at the same distance and the rotation angle thereof. Regarding the mounting angle θa and mounting height da when the TOF sensor 20 is rotating, as shown in Figures 11(a) and 11(b), the pixels of θ1 and θ2 can be similarly calculated by defining the distances d1 and d2 as the pixel distances at the intersection of the same field-angle circle and the vertical line passing through the center of the diameter line a connecting the same distance described above.

[0063] The correction possibility determination unit 15 determines whether or not to correct the measurement results (distance information) in the distance information calculation unit 24a of the control unit 24 based on the information on the mounting angle and rotation angle detected in the mounting angle detection unit 14a and rotation detection unit 14c of the mounting posture detection device 10. Here, a case where correction is not possible is, for example, when the transport device 30 collides with an unexpected obstacle while traveling, resulting in a large distortion in the mounting posture of the TOF sensor 20.

[0064] The determination of whether or not correction is possible is made depending on whether or not the mounting angle and rotation angle detected by the mounting angle detection unit 14a and rotation detection unit 14c of the mounting posture detection device 10 are within a predetermined correctable reference range. As a result, if the detection result of the mounting posture detection device 10 indicates a large distortion in the mounting posture of the TOF sensor 20, the distance value that is the measurement result is not corrected, and measures can be taken such as notifying the user to adjust the mounting posture of the TOF sensor 20.

[0065] The storage unit 16 stores information about the mounting attitude (mounting angle, rotation angle, etc.) of the TOF sensor 20 detected by the mounting attitude detection unit 14. This allows the TOF sensor 20 to correct the measurement results (distance information) using information about the mounting attitude of the TOF sensor 20 stored in the storage unit 16. For example, if the correction feasibility determination unit 15 determines that the distance information cannot be corrected, the notification unit 17 notifies the user to adjust the mounting posture of the TOF sensor 20, since there is a high possibility that the mounting posture of the TOF sensor 20 is extremely misaligned.

[0066] <Installation posture detection method> The method for detecting the mounting attitude of the TOF sensor 20 according to this embodiment will be described below with reference to the flowchart shown in FIG. Here, a process of detecting the mounting angle θa and the mounting height da as the mounting attitude of the TOF sensor 20 will be described.

[0067] 12, in step S11, it is determined whether or not the central pixel P0 of the TOF sensor 20 is within the floor surface FL. If the central pixel P0 is within the floor surface FL, the process proceeds to step S13, and if it is outside the floor surface FL, the process proceeds to step S12a. It should be noted that the determination in step S11 does not necessarily have to be based on the central pixel, and a pixel other than the central pixel may be used, but in this embodiment, the central pixel will be used for the sake of simplicity.

[0068] Here, in step S12a, since it was determined in step S11 that the central pixel P0 is outside the floor surface FL, the notification unit 17 notifies the user that information regarding the mounting attitude of the TOF sensor 20 cannot be detected. Next, in step S13, since it was determined in step S11 that the central pixel P0 is within the floor surface FL, light is emitted from the lighting unit 21, the reflected light is received by the image sensor 23, and the measurement value (distance information) of the central pixel P0 of the TOF sensor 20 is set to d.

[0069] Next, in step S14, an arbitrary pixel P1 having the same x-coordinate as the center pixel P0 is selected. Note that P1 is on the floor surface FL, and the angle between the center pixel P0 and the arbitrary pixel P1 is defined as θ1, and the measurement value (distance) of the arbitrary pixel P1 is defined as d1 (distance and angle information acquisition step). Next, in step S15, an arbitrary pixel P2 having the same x-coordinate as the center pixel P0 is selected. The arbitrary pixel P2 is located on the floor surface FL, and the angle between the center pixel P0 and the arbitrary pixel P2 is θ2, and the measurement value (distance) of the arbitrary pixel P2 is d2.

[0070] Next, in step S16, as described above, the mounting angle θa and mounting height da of the TOF sensor 20 are calculated by the following equations (1) and (2) (mounting attitude detection step). da=d1cos(θa-θ1) ····(1) da=d2cos(θa-θ2) ····(2) Next, in step S17, it is determined whether or not the mounting angle θa and mounting height da of the TOF sensor 20 are within a reference range.

[0071] The reference range may be set to any range depending on the user's preference, the type, shape, performance, etc. of the TOF sensor 20. Here, in step S12b, since it was determined in step S17 that the mounting angle θa and mounting height da were outside the reference range, the notification unit 17 notifies the user that the measurement results measured by the TOF sensor 20 cannot be corrected.

[0072] Next, in step S18, since it has been determined in step S17 that the mounting angle θa and the mounting height da are within the reference range, the mounting angle θa and the mounting height da are stored in the storage unit 16. Next, in step S19, the measurement results of the TOF sensor 20 are corrected based on the values ​​of the mounting angle θa and the mounting height da, and the process ends.

[0073] After step S19, coordinate conversion may be performed using the values ​​of the mounting angle θa and the mounting height da when measuring the distance by the TOF sensor 20. Alternatively, the user may adjust the mounting posture of the TOF sensor 20 by referring to the values ​​of the mounting angle θa and the mounting height da. Next, the process of detecting the rotation angle θb as the mounting attitude of the TOF sensor 20 will be described below with reference to FIG.

[0074] 13, in step S21, it is determined whether or not the central pixel P0 of the TOF sensor 20 is within the floor surface FL. If the central pixel P0 is within the floor surface FL, the process proceeds to step S23, and if it is outside the floor surface FL, the process proceeds to step S22a. Here, in step S22a, since it was determined in step S21 that the central pixel P0 is outside the floor surface FL, the notification unit 17 notifies the user that information regarding the mounting attitude of the TOF sensor 20 cannot be detected.

[0075] Next, in step S23, since it has been determined in step S21 that the central pixel P0 is within the floor surface FL, a circle C having the central pixel P0 of the TOF sensor 20 as its center is defined on the floor surface FL. Next, in step S24, the distance values ​​of the pixels on the circumference of the circle C are read (distance information acquisition step).

[0076] Next, in step S25, pixels P3 and P4 are determined as being at the same distance from the distance values ​​obtained in step S24. Next, in step S26, it is determined whether pixel P3, central pixel P0, and pixel P4 are not aligned on the same Y coordinate. If pixel P3, central pixel P0, and pixel P4 are not aligned on the same Y coordinate, the process proceeds to step S28; if they are aligned, the process proceeds to step S27.

[0077] Next, in step S27, in step S26, since it is determined that the pixel P3, the central pixel P0, and the pixel P4 are arranged on the same Y coordinate, it is determined that the rotation of the TOF sensor 20 is 0 degrees (no deviation in the mounting posture in the rotation direction), and the process ends. At this time, it may be notified to the user via the notification unit 17 that there is no need for correction due to the rotation of the TOF sensor 20.

[0078] Next, in step S28, assuming the coordinates of the central pixel P0 are (x0, y0), and the angle formed by the line connecting the pixels P3, P0, P4 and the line Y = y0 is defined as the rotation angle θb in the optical axis direction (mounting posture detection step). Next, in step S29, it is determined whether the rotation angle θb is within the reference angle range. If it is within the reference angle range, the process proceeds to step S30. If it is outside the reference angle range, the process proceeds to step S22b.

[0079] Here, in step S22b, since it is determined in step S29 that the rotation angle θb is outside the reference angle range, the notification unit 17 notifies the user that the measurement result of the TOF sensor 20 cannot be corrected. Next, in step S30, since it is determined in step S29 that the rotation angle θb is within the reference angle range, the rotation angle θb is saved in the storage unit 16.

[0080] Next, in step S31, based on the value of the rotation angle θb, the result (distance value) measured by the TOF sensor 20 is corrected and the process ends. Note that after step S31, coordinate transformation may be performed when measuring the distance by the TOF sensor 20 using the rotation angle θb. Alternatively, the user may adjust the rotation angle of the TOF sensor 20 referring to the value of the rotation angle θb.

[0081] <Mounting Posture Detection Method at Return to DOCK> Regarding the process performed when the transport system 50 returns to the DOCK 40 as the mounting posture detection method of the TOF sensor 20 in the present embodiment, it is as follows when described using the flowchart shown in FIG. 14. Here, we will explain the process of adjusting the mounting posture using the mounting angle θa, mounting height da, and rotation angle θb detected when the conveying device 30 equipped with the TOF sensor 20 completes the specified work and returns to the DOCK 40.

[0082] 14, in step S41, it is determined whether or not it is recognized that the transport device 30 is connected to the DOCK 40. If it is recognized that the transport device 30 is connected to the DOCK 40, the process proceeds to step S43, and if it is not recognized, the process proceeds to step S42. Here, in step S42, since it is determined in step S41 that the transport device 30 is not recognized as being connected to the DOCK 40, steps S41 and S42 are repeated until the transport device 30 is connected to the DOCK 40.

[0083] Next, in step S43, since it is determined in step S41 that the transport device 30 is recognized as being connected to the DOCK 40, the exposure time Inti of the image pickup element 23 of the TOF sensor 20 is initially set. Next, in step S44, it is determined whether or not the mark M on the chart can be identified by the TOF sensor 20. If the mark M can be identified, the process proceeds to step S46, and if it cannot be identified, the process proceeds to step S45.

[0084] Next, in step S45, since it was determined in step S44 that the mark M on the chart cannot be identified by the TOF sensor 20, adjustment is made to the exposure time Inti of the image sensor 23 of the TOF sensor 20. This adjustment process of the exposure time Inti is repeated until the mark M on the chart is recognized. Next, in step S46, since it was determined in step S44 that the mark M on the chart can be identified by the TOF sensor 20, the TOF sensor 20 captures an image of the mark M drawn substantially parallel to the front of the conveyance device 30 together with the floor surface FL.

[0085] At this time, the TOF sensor 20 is aligned so that the front of the conveying device 30 is approximately parallel to the line segment L2 of the mark M, and therefore, by measuring the distance to the two reference points P1 and P2 on the floor surface FL in this state, the installation posture can be detected more accurately. Next, in step S47, two reference points P1 and P2 are set on the photographed floor surface FL, and the mounting angle θa and mounting height da of the TOF sensor 20 are calculated using the above-mentioned equations (1) and (2) (distance information acquisition step, angle information acquisition step, mounting posture detection step).

[0086] Next, in step S48, it is determined whether the mounting angle θa of the TOF sensor 20 calculated in step S47 is within a reference range. If it is determined that the mounting angle θa is within the reference range, the process proceeds to step S50, and if it is determined that it is outside the reference range, the process proceeds to step S49. The reference range may be set to any range depending on the user's preference, the type, shape, performance, etc. of the TOF sensor 20.

[0087] Next, in step S49, since it was determined in step S48 that the mounting angle θa was outside the reference range, the notification unit 17 notifies the user that the measurement results measured by the TOF sensor 20 cannot be corrected using the mounting angle θa. Next, in step S50, since it is determined in step S48 that the mounting angle θa is within the reference range, the rotation detection unit 14c described above performs a calculation process for the rotation angle θb (mounting attitude detection step).

[0088] Next, in step S51, it is determined whether the rotation angle θb is within a reference angle range in which it can be corrected. If it is within the reference angle range, the process proceeds to step S53, and if it is outside the reference angle range, the process proceeds to step S52. Here, in step S52, since it was determined in step S51 that the rotation angle θb is outside the reference angle range, the notification unit 17 notifies the user that the measurement result of the TOF sensor 20 cannot be corrected using the rotation angle θb.

[0089] Next, in step S53, since it is determined in step S51 that the rotation angle θb is within the reference angle range, the optical axis coordinate system of the TOF sensor 20 is converted into an orthogonal coordinate system parallel to the floor surface FL. Specifically, the TOF optical axis coordinate system (X T ,Y T ,Z T ) and the three axes (X TH ,Y TH ,Z TH ) and stores it in the storage unit 16.

[0090] Next, in step S54, the Cartesian coordinate system parallel to the floor surface FL, which has been converted in step S53, is converted into the Cartesian coordinate system of the transport device 30. Specifically, the three axes (X TH ,Y TH ,Z TH ) to the Cartesian coordinate system (X A ,Y A ,Z A ) and stores it in the storage unit 16.

[0091] Next, in step S55, it is determined whether the difference compared to the previous conversion coefficient is equal to or greater than a predetermined threshold. If the difference is equal to or greater than the predetermined threshold, the process proceeds to step S56. If it is less than the threshold, it is determined that further adjustment is not necessary and the process ends. Next, in step S56, since it was determined in step S55 that the difference in the conversion coefficient from the previous ratio is equal to or greater than a predetermined threshold, the notification unit 17 notifies the user that the mounting posture of the TOF sensor 20 has shifted significantly compared to the time of the previous adjustment. Next, in step S57, since it is found that the mounting posture of the TOF sensor 20 has shifted significantly compared to the previous adjustment, the mounting angle θa, mounting height da, and rotation angle θb of the TOF sensor 20 mounted on the conveying device 30 are adjusted.

[0092] <Main features> The conveyance system 50 of this embodiment includes a main body 31, a TOF sensor 20, and an installation attitude detection device 10. The TOF sensor 20 includes an illumination unit 21 that irradiates a floor surface FL with light, an imaging element 23 that detects the light irradiated from the illumination unit 21, a distance information acquisition unit 11 that acquires distance information to reference points P1 and P2 on the floor surface FL based on the phase difference between the received light wave and the projected light wave detected by the imaging element 23, and an angle information acquisition unit 12 that acquires angle information to the reference points P1 and P2, and is attached to the main body 31. The installation attitude detection unit 14 detects the installation attitude of the TOF sensor 20 with respect to the floor surface FL based on the distance information and angle information acquired by the distance information acquisition unit 11 and the angle information acquisition unit 12.

[0093] This makes it possible to automatically detect the mounting orientation of the TOF sensor 20 relative to a reference surface such as the floor surface FL using the results of measurement by the TOF sensor 20 (distance information and angle information). Therefore, without performing measurements using posture detection equipment such as an inclination sensor or a level, the mounting posture of the TOF sensor 20 attached to various devices can be detected, and the measurement results of the TOF sensor 20 can be corrected appropriately depending on any disturbance in the mounting posture.

[0094] [Other embodiments] Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the gist of the invention. (A) In the above embodiment, an example has been described in which the TOF sensor 20 (distance measurement device) is attached to the transport device 30. However, the present invention is not limited to this.

[0095] For example, the distance measurement device 120 (mounting attitude detection device 110) may be configured to be installed inside a monitoring device attached to a wall surface inside a room, or inside a surveillance camera, as shown in FIG. 15, other than the conveying device. In this case, the mounting orientation of the monitoring device can be automatically detected by arranging the camera with the optical axis AX facing the floor surface so that the floor surface serves as the reference plane. The mounting attitude detection device of the present invention may also be mounted on other devices, such as vehicles, including automobiles, motorcycles, and electric bicycles.

[0096] (B) In the above embodiment, an example has been described in which the mounting attitude detection device 10 is provided inside the TOF sensor 20. However, the present invention is not limited to this. For example, the mounting posture detection device 10 may be configured to be provided outside the TOF sensor 20 as shown in FIG. Alternatively, the mounting posture detection device 10 may be configured to be provided inside a transport device 30 to which a distance measurement device such as a TOF sensor is attached, as shown in FIG.

[0097] (C) In the above embodiment, an example has been described in which the mounting angle, mounting height, and rotation angle with respect to the floor surface FL are detected as the mounting posture of the TOF sensor 20. However, the present invention is not limited to this. For example, other than the mounting angle etc. described above, other mounting attitudes such as twisting may be detected.

[0098] (D) In the above embodiment, an example has been described in which the mounting angle, mounting height, etc. of the TOF sensor 20 are detected using distance information from the TOF sensor 20 to two points on the floor surface FL. However, the present invention is not limited to this. For example, the mounting angle, mounting height, etc. may be detected using distances to three or more points on a reference plane such as a floor surface.

[0099] (E) In the above embodiment, an example has been described in which the floor surface FL is used as the reference surface when automatically detecting the mounting posture of the TOF sensor 20. However, the present invention is not limited to this. For example, in addition to the floor surface, other surfaces such as a wall surface or a ceiling surface may be used as the reference surface.

[0100] (F) In the above embodiment, an example has been described in which the position where the DOCK 40 is installed is used as the predetermined return position to detect the mounting attitude of the TOF sensor 20. However, the present invention is not limited to this. For example, if there is no inclination on the reference surface such as the floor surface, it is not necessary to detect the mounting attitude at a specific position, and the mounting attitude may be detected at any desired position and timing.

[0101] (G) In the above embodiment, an example has been described in which the TOF sensor 20 is used as the distance measurement device, but the present invention is not limited to this.

[0102] For example, instead of a TOF sensor, other distance measurement devices such as LiDAR (Light Detection And Ranging) or SC (Structural Camera) that can acquire distance information to a reference point and have angle information to the reference point may be used. [Industrial Applicability]

[0103] The distance measurement system of the present invention has the effect of being able to detect the installation posture of a distance measurement device attached to the main body without using posture detection equipment such as an inclination sensor or a spirit level, and is therefore widely applicable to various systems including distance measurement devices. [Explanation of symbols]

[0104] 10 Mounting position detection device 11 Distance information acquisition section 12 Angle information acquisition section 13 Range image acquisition unit 14 Mounting position detection unit 14a Mounting angle detection unit 14b Mounting height detection unit 14c Rotation detector 15 Correction possibility determination section 16 Memory section 17 Notification Department 20 TOF sensor (distance measuring device) 21 Lighting Department 22 Receiving lens 23 Imaging element (detection unit) 24 Control Unit 24a Distance information calculation unit 24b Angle information acquisition section 24c Distance image generation section 24d distance correction processing section 25 Memory section 30 Conveying device (predetermined object) 31 Main body 32 Drive unit 32a wheels 33 Fork 34 Drive control unit 35 Charging terminal 36 Secondary battery 40 DOCK (return location, charging station) 41 Connection 42 Power supply unit (charging device) 50 Conveying system (distance measuring system) 110 Mounting posture detection device 120 TOF sensor (distance measuring device) AX optical axis C yen d,d1,d2 distance da height (distance) FL floor surface (reference surface) L1 light L2 line segment P0 Image center (pixel) P1,P2 reference point P3, P4 pixels S1 Object θ1, θ2 angle information θa Mounting angle θb rotation angle

Claims

1. A distance measurement system including a distance measurement device that measures a distance to an object according to a phase difference between a projected light wave irradiated onto the object and a received light wave, a distance measuring device having an illumination unit that irradiates the light onto a predetermined reference plane, a detection unit that detects the light irradiated from the illumination unit, a distance information acquisition unit that acquires distance information to a reference point on the reference plane according to a phase difference between a received wave of the light detected by the detection unit and an irradiated wave, and an angle information acquisition unit that acquires angle information to the reference point; a main body portion serving as a housing to which the distance measuring device is attached; an attachment attitude detection unit that detects an attachment attitude of the distance measurement device with respect to the reference surface based on the distance information and angle information acquired by the distance information acquisition unit and the angle information acquisition unit; Equipped with the distance measurement device further includes a distance image generation unit that generates a distance image including the reference plane based on results acquired by the distance information acquisition unit and the angle information acquisition unit; a distance image acquisition unit that acquires the distance image from the distance image generation unit; the mounting attitude detection unit detects the rotation of the mounting attitude of the distance measurement device based on whether or not the position of a pixel in the distance image acquired by the distance image acquisition unit, at which the distance to the reference surface is the same, has moved from a predetermined reference position. Distance measurement system.

2. The main body includes wheels that can run on the reference surface, a drive unit that drives the wheels to rotate, and a drive control unit that controls the drive unit.

2. The distance measurement system according to claim 1.

3. the drive control unit controls the drive unit to rotate the wheels, and moves the vehicle to a predetermined return position.

3. A distance measurement system according to claim 2.

4. The vehicle further includes a charging station provided at the return location and to which a portion of the main body is connected.

4. A distance measurement system according to claim 3.

5. the main body portion has a secondary battery that supplies power to the drive portion, The charging station has a charging device that charges the secondary battery.

5. A distance measurement system according to claim 4.

6. the distance information acquisition unit acquires the distance information relative to the reference point acquired at the return position. A distance measurement system according to any one of claims 3 to 5.

7. the mounting attitude detection unit detects the mounting attitude using distance information and angle information relative to the reference plane acquired at the return position.

7. A distance measurement system according to claim 6.

8. the mounting attitude detection unit detects at least one of an inclination angle of the distance measurement device with respect to the reference plane, a distance from the reference plane, and a rotation angle of the distance measurement device with respect to the reference plane as the mounting attitude; A distance measurement system according to any one of claims 1 to 7.

9. the mounting attitude detection unit detects the mounting attitude using distance information to two reference points on the reference surface and the angle information. A distance measurement system according to any one of claims 1 to 8.

10. the mounting attitude detection unit detects the mounting attitude of the distance measurement device using a first distance to a first reference point on the reference surface at a first pixel included in the distance image acquired by the distance image acquisition unit and a first angle with respect to the reference surface, and a second distance to a second reference point on the reference surface at a second pixel different from the first pixel and a second angle with respect to the reference surface.

3. A distance measurement system according to claim 1 or 2.

11. the mounting attitude detection unit detects rotation with respect to the reference plane as the mounting attitude of the distance measurement device using a first angle of a first pixel included in the distance image acquired by the distance image acquisition unit with respect to an irradiation axis of the light irradiated from the illumination unit, and a second angle of a second pixel different from the first pixel with respect to the irradiation axis of the light irradiated from the illumination unit.

3. A distance measurement system according to claim 1 or 2.

12. A distance measurement system including a distance measurement device that measures a distance to an object according to a phase difference between a projected light wave irradiated onto the object and a received light wave, a distance measuring device having an illumination unit that irradiates the light onto a predetermined reference plane, a detection unit that detects the light irradiated from the illumination unit, a distance information acquisition unit that acquires distance information to a reference point on the reference plane according to a phase difference between a received wave of the light detected by the detection unit and an irradiated wave, and an angle information acquisition unit that acquires angle information to the reference point; a main body portion serving as a housing to which the distance measuring device is attached; an attachment attitude detection unit that detects an attachment attitude of the distance measurement device with respect to the reference surface based on the distance information and angle information acquired by the distance information acquisition unit and the angle information acquisition unit; Equipped with the distance measurement device further includes a distance image generation unit that generates a distance image including the reference plane based on results acquired by the distance information acquisition unit and the angle information acquisition unit; a distance image acquisition unit that acquires the distance image from the distance image generation unit; the mounting attitude detection unit detects a rotation angle of the mounting attitude of the distance measurement device based on how many degrees a position of a pixel at which the distance to the reference surface is the same in the distance image acquired by the distance image acquisition unit is rotated from a predetermined reference position. Distance measurement system.

13. The distance measuring device further includes a correction possibility determination unit that determines whether or not to correct the measurement result of the distance measuring device based on the detection result of the mounting attitude detection unit. A distance measurement system according to any one of claims 1 to 12.

14. The distance measuring device further includes a storage unit for storing information about the mounting posture of the distance measuring device detected by the mounting posture detection unit. A distance measurement system according to any one of claims 1 to 13.

15. The reference surface is a floor surface. A distance measurement system according to any one of claims 1 to 14.

16. The distance measurement device is any one of a TOF (Time-of-Flight) sensor, a LiDAR (Light Detection And Ranging), or a SC (Structural Camera); A distance measurement system according to any one of claims 1 to 15.

Images