Measuring device and calibration method

Abstract

This measuring device acquires information relating to the position of a measurement target object, by emitting measurement light at the measurement target object. The measurement device comprises an emitting device that emits calibration light used to calibrate the measuring device, a first reflecting member, a support member that can rotate around a first axis of rotation and on which the first reflection member is provided, and a detector that can receive reflected light of the calibration light from the first reflecting member, wherein: the first reflecting member can reflect the calibration light emitted from the emitting device toward a second reflecting member disposed on the support member, and can reflect reflected light of the calibration light from the second reflecting member; and the detector can receive reflected light of the calibration light from the second reflecting member disposed on the support member via the first reflecting member.

Description

Measurement equipment and calibration method

[0001] The present invention relates to a measurement device and a calibration method.

[0002] As an example of a measurement system capable of measuring the position of a measurement object, Patent Document 1 describes a measurement system capable of measuring the position of a robot, which is an example of a measurement object. There is a demand for improving the measurement accuracy of such measurement systems.

[0003] U.S. Patent No. 8,036,552

[0004] According to a first aspect of the disclosure, a measurement device is a measurement device that irradiates a measurement object with measurement light and acquires information regarding the position of the measurement object, and includes an emission device that emits calibration light used to calibrate the measurement device, a first reflecting member, a support member that is rotatable around a first rotation axis and on which the first reflecting member is provided, and a detector that can receive the calibration light reflected from the first reflecting member, wherein the first reflecting member can reflect the calibration light emitted from the emission device toward a second reflecting member arranged on the support member and can reflect the calibration light reflected from the second reflecting member, and the detector can receive the calibration light reflected from the second reflecting member arranged on the support member via the first reflecting member.

[0005] According to a second aspect of the disclosure, a calibration method is a method for calibrating a measurement device that irradiates a measurement object with measurement light and acquires information regarding the position of the measurement object, and includes emitting calibration light used to calibrate the measurement device from an emitting device, reflecting the calibration light emitted from the emitting device toward a second reflecting member arranged on a support member that is rotatable around a first rotation axis by a first reflecting member provided on the support member, and receiving the reflected light of the calibration light from the second reflecting member arranged on the support member by a detector via the first reflecting member.

[0006] According to a third aspect of the disclosure, the measurement device is a measurement device that irradiates a measurement object with measurement light and acquires information regarding the position of the measurement object, and includes an emitting device that emits calibration light used to calibrate the measurement device, a first reflecting member, a support member that is rotatable around a first rotation axis and on which the first reflecting member is provided, and a detector that can receive the reflected light of the calibration light from the first reflecting member, and controls the irradiation direction of the measurement light based on the result of receiving the reflected light of the calibration light by the detector.

[0007] According to a fourth aspect of the disclosure, a calibration method is a method for calibrating a measurement device that irradiates a measurement object with measurement light and acquires information regarding the position of the measurement object, and includes emitting calibration light used to calibrate the measurement device from an emitting device, reflecting the calibration light emitted from the emitting device toward a detector by a first reflecting member provided on a support member that is rotatable around a first rotation axis, allowing the detector to receive the reflected light of the calibration light from the first reflecting member, and controlling the irradiation direction of the measurement light based on the result of receiving the reflected light of the calibration light by the detector.

[0008] According to a fifth aspect of the disclosure, a measurement device is a measurement device that irradiates a measurement object with measurement light and acquires information regarding the position of the measurement object, and includes an emitting device that emits calibration light used to calibrate the measurement device, a first reflecting member, a detector that can receive reflected light of the calibration light from the first reflecting member, a storage unit that houses the emitting device and the detector, and a support member that is rotatable around a first rotation axis and supports the storage unit rotatably around a second rotation axis that intersects the first rotation axis, and the first reflecting member is arranged to intersect the first rotation axis, and controls the irradiation direction of the measurement light based on the light reception result of the calibration light reflected by the first reflecting member received by the detector.

[0009] According to a sixth aspect of the disclosure, a calibration method is a method for calibrating a measurement device that irradiates a measurement object with measurement light and acquires information regarding the position of the measurement object, and includes emitting calibration light used to calibrate the measurement device from an emitting device, receiving reflected light of the calibration light from a first reflecting member by a detector that is rotatably supported around a second rotation axis intersecting the first rotation axis by a support member that is rotatable around the first rotation axis and is housed in a housing that houses the emitting device, and controlling the irradiation direction of the measurement light based on the light reception result of the reflected light of the calibration light reflected by the first reflecting member received by the detector, wherein the first reflecting member is arranged to intersect the first rotation axis.

[0010] The configurations of the embodiments described below may be modified as appropriate, and at least a portion of the configuration may be replaced with other components. Furthermore, components that are not particularly limited in terms of their placement may be placed in any position that can achieve their function, not limited to the placement disclosed in the embodiments.

[0011] FIG. 1A is a block diagram showing the configuration of a measurement system according to a first embodiment, and FIG. 1B is a block diagram showing the configuration of a measurement device according to the first embodiment. FIG. 2A is a perspective view showing an overview of the measurement device according to the first embodiment, FIG. 2B is a front view of the measurement device according to the first embodiment, and FIG. 2C is a side view of the measurement device according to the first embodiment. FIG. 3 is a cross-sectional view taken along line A-A in FIG. 2C. FIG. 4 is a cross-sectional view taken along line B-B in FIG. 2B. FIG. 5 is a block diagram showing the configuration of a control device. FIG. 6A is a diagram showing an ideal state in which there is no beam offset, and FIG. 6B is a diagram for explaining angle measurement errors when beam offset occurs. FIG. 7A is a diagram showing an ideal state in which there is no beam offset, and FIG. 7B is a diagram for explaining distance measurement errors when beam offset occurs. FIG. 8 is a cross-sectional view schematically showing the optical paths of the calibration light irradiated onto a calibration reflector by the measurement device and the calibration reflected light from the calibration reflector detected by the measurement device. Fig. 9(A) is a diagram showing the optical paths of the measurement light and the reflected light when the measurement light whose optical axis is offset from the azimuth axis is emitted with the center of the azimuth axis reflected by the mirror coinciding with the center of the reflector, and Fig. 9(B) is a diagram showing an example of the trajectory of the reflected light. Fig. 10(A) is a diagram showing a state in which the reflected light is not incident on the reflected light return point, and Fig. 10(B) is a diagram showing a state in which the attitude (elevation angle) of the mirror is changed from the state of Fig. 10(A) so that the reflected light is incident on the reflected light return point. Fig. 11(A) is a diagram showing a state in which the reflected light is not incident on the reflected light return point, and Fig. 11(B) is a diagram showing a state in which the attitude (elevation angle) of the mirror is changed from the state of Fig. 11(A) so that the reflected light is incident on the reflected light return point. Figs. 12(A) and 12(B) are diagrams for explaining beam tilt. FIG. 13A is a diagram for explaining the rotation angle az around the azimuth axis, and FIGS. 13B and 13C are diagrams for explaining the calculation of the beam tilt angle around the X axis.FIG. 14(A) is a diagram showing a state in which a mirror tilt occurs, and FIG. 14(B) shows an example of the trajectory of the calibration reflected light when the mirror with mirror tilt is rotated around the azimuth axis while irradiating the mirror with calibration light. FIG. 15(A) is a YZ cross-sectional view illustrating the distance between the azimuth axis and the incident position of the calibration reflected light when the rotation angle az = 0°, and FIG. 15(B) is a YZ cross-sectional view illustrating the distance between the azimuth axis and the incident position of the calibration reflected light when the rotation angle az = 180°. FIG. 16(A) is a perspective view showing an overview of a measurement device according to a second embodiment, and FIG. 16(B) is a diagram showing a schematic configuration of the measurement device according to the second embodiment. FIG. 17(A) is a diagram showing an example arrangement of a calibration reflector in the second embodiment, and FIG. 17(B) is a diagram showing the trajectory of the calibration reflected light acquired by a detector. 18(A) and 18(B) are diagrams for explaining calculation of the beam tilt angle around the elevation axis in the second embodiment. FIGS. 19(A) to 19(D) are diagrams for explaining calculation of the beam tilt angle around an axis perpendicular to the elevation axis in a plane perpendicular to the azimuth axis in the second embodiment. FIG. 20(A) is a diagram showing another example of the arrangement of the calibration reflector or calibration mirror, and FIG. 20(B) is a diagram showing another example of the arrangement of the calibration reflector and calibration mirror. FIG. 21 is a graph showing the transition of the residual in the approximation process when the trajectory of the calibration reflected light is approximated by a circle in the beam offset calibration process of the first embodiment. FIG. 22 is a diagram showing an application example of the measurement device.

[0012] First Embodiment A configuration of a measurement system SYS including a measurement device 100 according to a first embodiment will be described below. Fig. 1A is a block diagram showing the configuration of the measurement system SYS.

[0013] The measurement system SYS is a system for measuring the position of a measurement object MT, and includes a measurement device 100 and a control device 200.

[0014] (Measurement Device 100) The measurement device 100 irradiates the measurement object MT with measurement light ML and acquires information about the position of the measurement object MT. More specifically, the measurement device 100 irradiates a reflector attached to the measurement object MT with the measurement light ML. Furthermore, in order to acquire information about the position of the measurement object MT, the measurement device 100 detects reflected light RL from the measurement object MT irradiated with the measurement light ML. More specifically, the measurement device 100 detects reflected light RL from the reflector attached to the measurement object MT.

[0015] In the following description, the reflector attached to the measurement target MT may be referred to as the reflector MT. The reflector MT is, for example, a retroreflector. A retroreflector is an optical element that reflects a beam in the incident direction regardless of the position or direction from which the beam is incident on the retroreflector. In other words, a retroreflector has a retroreflecting function.

[0016] Fig. 1(B) is a block diagram showing the configuration of the measurement device 100. Fig. 2(A) is a perspective view showing an overview of the measurement device 100, Fig. 2(B) is a front view of the measurement device 100, and Fig. 2(C) is a side view of the measurement device 100. Fig. 3 is a cross-sectional view taken along line A-A in Fig. 2(C). Fig. 4 is a cross-sectional view taken along line B-B in Fig. 2(B).

[0017] 1B to 4, the measurement device 100 includes a rangefinder 101, a measurement optical system 102, a mirror 103, and a detector 104. Using the rangefinder 101, the measurement optical system 102, the mirror 103, and the detector 104, the measurement device 100 irradiates a measurement object MT with measurement light ML and detects reflected light RL from the measurement object MT.

[0018] Here, the rangefinder 101, the measurement optical system 102, the mirror 103, and the detector 104 will be described in detail with reference to Fig. 4. Fig. 4 schematically shows the optical paths of the measurement light ML that the measurement device 100 irradiates onto the measurement object MT and the reflected light RL that the measurement device 100 detects.

[0019] The rangefinder 101 measures the distance from the rangefinder 101 to the measurement target MT. The rangefinder 101 is, for example, an optical comb interferometer. The optical comb interferometer measures the distance from itself to the measurement target. The optical comb interferometer includes an optical comb light source. The optical comb light source is a light source capable of generating pulsed light containing frequency components equally spaced on the frequency axis (hereinafter referred to as an "optical frequency comb"). In this case, the optical comb light source emits pulsed light containing frequency components equally spaced on the frequency axis as measurement light. The optical comb interferometer irradiates the optical frequency comb as measurement light onto a reflecting element arranged on the measurement target. The optical comb interferometer receives reflected light generated when the optical frequency comb is reflected by a reflector. Note that the distance system 101 is not limited to an optical comb interferometer, and other measuring devices may be used.

[0020] 1B, the rangefinder 101 includes an emitter 101a as an emitter, a light-receiving unit 101b, and a signal processor 101c. The emitter 101a includes a light source and a frequency controller. The emitter 101a emits pulsed light generated by the light source as measurement light ML. The emitter 101a also branches a portion of the pulsed light generated by the light source and irradiates the branched light onto a reference surface within the rangefinder 101 as reference light.

[0021] The light receiving unit 101b includes a photodetector. The photodetector detects interference light between reflected light RL generated when the measurement light ML is reflected by the measurement object MT and the reference light irradiated on the reference surface. When the detection result from the photodetector is input, the signal processing unit 101c calculates the distance from the rangefinder 101 to the measurement object MT based on the generation position of the pulsed light that creates the interference light between the reflected light RL and the reference light. In the following description, information including the distance from the rangefinder 101 to the measurement object MT calculated by the signal processing unit 101c will be referred to as distance information. The signal processing unit 101c outputs the distance information to the control device 200.

[0022] The measurement optical system 102 is, for example, a half mirror, and emits at least a portion of the measurement light ML incident on the measurement optical system 102 toward the mirror 103. For example, the measurement optical system 102 may use a refractive optical element (for example, a lens) to emit at least a portion of the measurement light ML incident on the measurement optical system 102 toward the mirror 103. For example, the measurement optical system 102 may use a reflective optical element (for example, a mirror) to emit at least a portion of the measurement light ML incident on the measurement optical system 102 toward the mirror 103. As a result, at least a portion of the measurement light ML generated by the emission unit 101a is incident on the mirror 103 via the measurement optical system 102. However, at least a portion of the measurement light ML generated by the emission unit 101a may be incident on the mirror 103 without passing through the measurement optical system 102. In this case, the measurement optical system 102 may be omitted.

[0023] The mirror 103 is a reflective member that has a reflective surface 130 and is capable of reflecting the measurement light ML incident on the mirror 103 toward the measurement object MT (more specifically, toward a reflector provided on the measurement object MT). The mirror 103 reflects the measurement light ML incident on the reflective surface 130 toward the measurement object MT. As a result, the measurement light ML reflected by the mirror 103 is irradiated onto the measurement object MT. In this embodiment, the mirror 103 has a reflectance of 100% for the measurement light ML, but may also be a mirror with a reflectance less than 100%.

[0024] In this embodiment, the measurement light ML generated by the emission unit 101a is irradiated onto the measurement object MT via the measurement optical system 102 and the mirror 103. The rangefinder 101 does not necessarily have to include the emission unit 101a. In this case, an emission device that emits the measurement light ML and the calibration light CL described later may be provided separately from the rangefinder 101. The measurement light ML and the calibration light CL generated by the emission device may be incident on the measurement optical system 102 of the measurement device 100. The measurement device 100 does not necessarily have to include the emission unit 101a and the emission device. In this case, the measurement light ML and the calibration light CL generated by a light source external to the measurement device 100 may be incident on the measurement optical system 102 of the measurement device 100.

[0025] The measurement object MT, which is irradiated with the measurement light ML reflected by the mirror 103, reflects at least a portion of the measurement light ML. At least a portion of the measurement light ML reflected by the measurement object MT is incident on the mirror 103 as reflected light RL. The mirror 103 reflects the reflected light RL incident on the mirror 103 toward the measurement optical system 102. As a result, the reflected light RL reflected by the mirror 103 is incident on the measurement optical system 102.

[0026] The measurement optical system 102 emits at least a portion of the reflected light RL incident on the measurement optical system 102 toward the detector 104. That is, at least a portion of the reflected light RL from the measurement object MT is incident on the detector 104 via the mirror 103 and the measurement optical system 102. However, at least a portion of the reflected light RL from the measurement object MT may be incident on the detector 104 without passing through the measurement optical system 102. In this case, the measurement device 100 does not need to be equipped with the measurement optical system 102.

[0027] The detector 104 receives and detects the reflected light RL that is incident on the detector 104. Reflected light detection information relating to the detection result of the reflected light RL by the detector 104 is output from the measurement device 100 to the control device 200.

[0028] In this embodiment, the detector 104 is a detector that includes a detection surface 140 capable of detecting the reflected light RL and is capable of detecting the position of the reflected light RL on the detection surface 140. An example of such a detector 104 is a position-sensitive detector (PSD). The optical position sensor is a detector that is capable of outputting information relating to the detection result of the reflected light RL, in which a voltage signal corresponding to the light amount of the reflected light RL on the detection surface 140 is associated with the position on the detection surface 140. The position of the reflected light RL on the detection surface 140 is represented, for example, by coordinates in an X1-Y1 Cartesian coordinate system. The control device 200 can calculate the position of the reflected light RL on the detection surface 140 (for example, the position of the beam spot formed by the reflected light RL on the detection surface 140) based on the reflected light detection information.

[0029] In the following description, an example will be described in which an optical position sensor capable of detecting the position of reflected light RL on the detection surface 140 is used as the detector 104. The measurement device 100 may be provided with a detector 104 used for position measurement operations and a detector 104 used for calibration operations separately. The detector 104 may be a CCD (Charged Coupled Device) image sensor, a CMOS (Complementary Metal Oxide Semiconductor) image sensor, a line sensor, or other photoelectric conversion element. The detection surface 140 of the detector 104 may or may not be divided into a plurality of divided detection surfaces.

[0030] The measurement apparatus 100 is capable of rotating the mirror 103 around a first rotation axis and also rotating the mirror 103 around a second rotation axis. In the following description, an example will be described in which the first rotation axis is a rotation axis parallel to the Z axis and the second rotation axis is a rotation axis perpendicular to the Z axis (for example, a rotation axis parallel to the X axis). In the following description, the first rotation axis parallel to the Z axis will be referred to as the azimuth axis AZ, and the second rotation axis perpendicular to the Z axis will be referred to as the elevation axis EL.

[0031] More specifically, the measurement device 100 includes a first support unit 105 that supports the mirror 103 rotatably around the elevation axis EL and a second support unit 106 that supports the first support unit 105 rotatably around the azimuth axis AZ. That is, the first support unit 105 is rotatable around the azimuth axis AZ and has the mirror 103 mounted thereon. The first support unit 105 is provided with a mirror drive device (not shown) that rotates the mirror 103 around the elevation axis EL. The second support unit 106 is provided with a drive device (not shown) that rotates the first support unit 105 around the azimuth axis AZ. When the second support unit 106 rotates the first support unit 105 around the azimuth axis AZ, the mirror 103 supported by the first support unit 105 also rotates around the azimuth axis AZ.

[0032] In this way, since the mirror 103 is rotatable around the azimuth axis AZ and the elevation axis EL, the measurement light ML emitted from the rangefinder 101 can be irradiated onto the measurement object MT.

[0033] (Control device 200) The control device 200 controls the measurement device 100 to perform a position measurement process for measuring the position of the measurement object MT. For example, the control device 200 controls the measurement device 100 to irradiate the measurement object MT with measurement light ML and detect reflected light RL from the measurement object MT. The control device 200 also controls the measurement device 100 to perform a calibration process (details of which will be described later) for the measurement device 100.

[0034] The configuration of the control device 200 will be described with reference to Fig. 5. Fig. 5 is a block diagram showing the configuration of the control device 200.

[0035] 5 , the control device 200 includes an arithmetic device 201, a storage device 202, and a communication device 203. The control device 200 may further include an input device 204 and an output device 205. However, the control device 200 does not necessarily include at least one of the input device 204 and the output device 205. The arithmetic device 201, the storage device 202, the communication device 203, the input device 204, and the output device 205 may be connected via a data bus 206.

[0036] The arithmetic device 201 includes at least one processor (i.e., one processor or multiple processors) as hardware. The processor may include, for example, a processor conforming to a von Neumann computer architecture. The processor conforming to the von Neumann computer architecture may include at least one of a CPU (Central Processing Unit) and a GPU (Graphics Processing Unit). The processor may include, for example, a processor conforming to a non-von Neumann computer architecture. The processor conforming to the non-von Neumann computer architecture may include at least one of an FPGA (Field Programmable Gate Array) and an ASIC (Application Specific Circuit).

[0037] The arithmetic device 201 reads a computer program PRG including at least one of computer program code and computer program instructions. For example, the arithmetic device 201 may read a computer program PRG stored in the storage device 202. For example, the arithmetic device 201 may read a computer program PRG stored in a computer-readable, non-transitory storage medium using a storage medium reading device (not shown) included in the control device 200. The computer program PRG read from the storage medium may be stored in the storage device 202. The arithmetic device 201 may acquire (i.e., download or read) the computer program PRG from a device (not shown) located outside the control device 200 via the communication device 203 (or another communication device). The downloaded computer program PRG may be stored in the storage device 202.

[0038] The arithmetic device 201 executes the loaded computer program PRG. As a result, logical functional blocks for executing the processing to be performed by the control device 200 (e.g., the position measurement processing and calibration processing described above) are realized within the arithmetic device 201. In other words, the arithmetic device 201, together with the storage device 202 or the like in which the computer program PRG is recorded (in other words, together with the storage device 202 and the computer program PRG recorded in the storage device 202 or the like), can function as a controller or computer for realizing the logical functional blocks for executing the processing to be performed by the control device 200. In other words, the at least one processor included in the arithmetic device 201, the memory (recording medium) included in the storage device 202 or the like, and the computer program PRG are configured so that the control device 200 performs the processing to be performed by the control device 200 (e.g., the position measurement processing and calibration processing).

[0039] A computational model that can be constructed by machine learning may be implemented in the computational device 201 by the computational device executing the computer program PRG. An example of a computational model that can be constructed by machine learning is a computational model including a neural network (so-called artificial intelligence (AI)). In this case, learning of the computational model may include learning of parameters of the neural network (e.g., at least one of a weight and a bias). The computational device 201 may execute a position measurement process and a calibration process using the computational model. That is, the operation of executing the position measurement process and the calibration process may include the operation of executing the position measurement process and the calibration process using the computational model. That is, the computational model may calculate a correction amount based on the measurement result. In this case, the computational model may be a single computational model that can calculate correction amounts for beam offset, beam tilt, and mirror tilt, which will be described later, or may be a plurality of computational models that can respectively calculate correction amounts for beam offset, beam tilt, and mirror tilt.

[0040] Note that the computational model may be used to correct all correction items (beam offset, beam tilt, and mirror tilt), or only some of the correction items. For example, in the beam offset calibration process described below, the mirror 103 is rotated around the azimuth axis AZ while the calibration light CL is irradiated onto the calibration reflector 107, and the incident position of the calibration reflected light CRL on the detection surface 140 of the detector 104 is measured at multiple measurement points. However, some of the values ​​(incident positions of the calibration reflected light CRL) among the multiple measurement points may be replaced with values ​​obtained using the computational model. Also, for example, the correction amount for the beam offset may be calculated using the computational model, and the correction amounts for the beam tilt and mirror tilt may be calculated using actual measurement results. Using the computational model makes it possible to reduce the number of measurement points required for correction. The computational model may also be used to determine the timing of correction. Note that the computational device 201 may be equipped with a computational model already constructed by offline machine learning using training data. Furthermore, the computational model may be constructed based on at least one of the attitude of the measurement device, the number of measurements taken by the measurement device, environmental information inside and outside the measurement device, and vibration information. By learning the computational model including at least one of the attitude of the measurement device, the number of measurements taken by the measurement device, environmental information inside and outside the measurement device, and vibration information, it is possible to construct a computational model that calculates a correction amount more accurately. Furthermore, the computational model implemented in the computational device 201 may be updated by online machine learning on the computational device 201. Alternatively, the computational device 201 may perform the position measurement process and the calibration process using a computational model implemented in a device external to the computational device 201 (i.e., a device provided outside the control device 200) in addition to or instead of the computational model implemented in the computational device 201.

[0041] The recording medium for recording the computer program PRG executed by the arithmetic device 201 may be at least one of the following: a CD-ROM, CD-R, CD-RW, a flexible disk, an MO, a DVD-ROM, a DVD-RAM, a DVD-R, a DVD+R, a DVD-RW, a DVD+RW, and an optical disk such as Blu-ray (registered trademark), a magnetic medium such as a magnetic tape, a magneto-optical disk, a semiconductor memory such as a USB memory, and any other medium capable of storing a program. The recording medium may include a device capable of recording the computer program PRG (for example, a general-purpose device or a dedicated device in which the computer program PRG is implemented in a state in which it can be executed in at least one of the forms of software and firmware). Furthermore, each process or function included in the computer program PRG may be realized by a logical processing block realized within the arithmetic device 201 when the arithmetic device 201 (i.e., processor) executes the computer program PRG, or may be realized by hardware such as a predetermined gate array (FPGA (Field Programmable Gate Array), ASIC (Application Specific Integrated Circuit)) provided in the arithmetic device 201, or may be realized in a form that mixes logical processing blocks and partial hardware modules that realize some elements of the hardware.

[0042] 5 shows an example of logical functional blocks implemented in the arithmetic device 201 for executing the position measurement process and the calibration process. As shown in FIG. 5, the arithmetic device 201 implements, for example, a rotation angle control unit 201a, a position calculation unit 201b, and a calibration processing unit 201c.

[0043] The storage device 202 includes at least one memory capable of storing desired data. In other words, the storage device 202 includes at least one memory containing desired data. For example, the storage device 202 may store a computer program PRG executed by the arithmetic device 201. In this case, the storage device 202 (memory) may be used as the above-mentioned recording medium for recording the computer program PRG executed by the arithmetic device 201. The storage device 202 may temporarily store data used by the arithmetic device 201 when the arithmetic device 201 is executing the computer program PRG. The storage device 202 may store data to be stored long-term by the control device 200. The storage device 202 may include at least one of a RAM (Random Access Memory), a ROM (Read Only Memory), a hard disk device, a magneto-optical disk device, an SSD (Solid State Drive), and a disk array device. That is, storage device 202 may include non-transitory storage media.

[0044] The control device 200 (rotation angle control unit 201a) controls the rotation angle of the mirror 103 about the elevation axis EL and about the azimuth axis AZ based on reflected light detection information related to the detection result of the reflected light RL by the detector 104. For example, the control device 200 controls the rotation angle of the mirror 103 about the elevation axis EL and about the azimuth axis AZ so that the reflected light is incident on a predetermined position on the detection surface 140 of the detector 104. Note that the measurement device 100 may also be equipped with the control device 200.

[0045] The control device 200 (position calculation unit 201b) calculates the position of the measurement object MT based on distance information regarding the distance between the rangefinder 101 and the measurement object MT when the reflected light is incident on a predetermined position on the detection surface 140 of the detector 104, and information regarding the irradiation direction of the measurement light ML from the mirror 103 (specifically, information regarding the rotation angle of the mirror 103 around the azimuth axis AZ obtained by an encoder not shown, and information regarding the rotation angle of the mirror 103 around the elevation axis EL obtained by an encoder not shown).

[0046] When measuring the position of the measurement object MT, if any of beam offset, beam tilt, and mirror tilt occurs, the position of the measurement object MT cannot be calculated accurately. Therefore, in this embodiment, the measurement system SYS executes beam offset calibration processing, beam tilt calibration processing, and mirror tilt calibration processing at predetermined timings, so that the position of the measurement object MT can be detected with high accuracy.

[0047] The measurement system SYS starts various calibration processes based on at least one of information about the state of the measurement device 100, information about time, environmental information about at least one of the external environment of the measurement device 100 and the internal environment of the measurement device 100, and instructions from an external device. Note that the various calibration processes do not have to be performed at the same time, and only one of the beam offset calibration process, beam tilt calibration process, and mirror tilt calibration process may be performed.

[0048] Examples of information related to the state of the measuring device 100 include information on whether the power of the measuring device 100 is on, the number of times the measuring device 100 has measured the position of the measurement target MT, and the attitude of the measuring device 100. For example, if the measuring device 100 is installed on an automatic guided vehicle (AGV) or a robot, the attitude of the measuring device 100 will change when the attitude of the automatic guided vehicle or the attitude of the robot changes. Furthermore, for example, the measuring system SYS may start various calibration processes when the number of times the measuring device 100 has measured the position of the measurement target MT reaches a predetermined number or more. Furthermore, examples of information related to time include predetermined time intervals (e.g., every tens of minutes or every few hours) or when a predetermined time has arrived. In other words, the measuring system SYS may periodically perform various calibration processes.

[0049] Examples of environmental information include the temperature and humidity inside the measurement device 100 and the temperature and humidity around the measurement device 100. The environmental information may be acquired from an environmental meter provided in the measurement device 100 or from an external environmental meter. For example, the measurement system SYS may start various calibration processes when the temperature inside or around the measurement device 100 reaches or exceeds a predetermined temperature, or when the humidity inside or around the measurement device 100 reaches or exceeds a predetermined humidity. Furthermore, the measurement system SYS may start various calibration processes when a vibration detector provided in the measurement device 100 or a vibration detector provided on the floor on which the measurement device 100 is installed detects vibration. An example of an instruction from an external device is an instruction from a robot or the like that uses the measurement results obtained by the measurement device 100.

[0050] In the following description, for convenience of explanation, the measurement light ML emitted from the rangefinder 101 in various calibration processes will be referred to as "calibration light CL" to distinguish it from the measurement light ML irradiated onto the measurement object MT to perform position measurement operations. That is, the measurement light ML and the calibration light CL are emitted from the emission unit 101a. In the following description, unless otherwise specified, the measurement light ML will be taken to mean the measurement light ML irradiated onto the measurement object MT to perform position measurement operations. In addition, in the emission unit 101a, the emission port of the measurement light ML and the emission port of the calibration light CL may be the same or different. Furthermore, the optical characteristics of the measurement light ML and the optical characteristics of the calibration light CL may be the same or different.

[0051] Similarly, in the following description, for convenience of explanation, the reflected light RL detected by the measurement device 100 in various calibration processes (i.e., the reflected light RL from the calibration reflector 107 or mirror 103 described below) will be referred to as "calibration reflected light CRL" to distinguish it from the reflected light RL detected by the measurement device 100 to perform a position measurement operation (i.e., the reflected light RL from the measurement object MT). Therefore, in the following description, unless otherwise specified, the reflected light RL will mean the reflected light RL detected by the measurement device 100 to perform a position measurement operation (i.e., the reflected light RL from the measurement object MT). Note that the measurement object MT may be measured using at least a portion of the calibration light CL. The measurement object MT may be measured using the calibration reflected light CRL. Calibration may be performed using the reflected light RL.

[0052] (Beam Offset Calibration Process) First, the beam offset calibration process will be described. The beam offset calibration process is a calibration process related to the positional relationship (shift) between the optical axis of the measurement optical system 102 that irradiates the measurement light ML and the azimuth axis AZ. Fig. 6A is a diagram showing an ideal state in which there is no beam offset. Note that Fig. 6A omits the measurement optical system 102 and illustrates how the reflected light RL is directly incident on the detector 104. The same applies to the other figures.

[0053] 6A, the ideal state is when the optical axis of the measurement light ML incident on the mirror 103 coincides with the azimuth axis AZ. In this case, if the irradiation direction of the measurement light ML (i.e., the irradiation direction of the measurement light ML from the mirror 103) is controlled based on reflected light detection information indicating the detection result of the reflected light RL by the detector 104, the position of the measurement object MT can be correctly detected (assuming that no beam tilt or mirror tilt occurs).

[0054] 6B is a diagram for explaining angle measurement errors when a beam offset occurs. The occurrence of a beam offset means that the optical axis of the measurement light ML does not coincide with (is shifted from) the azimuth axis AZ. In FIG. 6B, the optical axis of the measurement light ML is offset by BO from the azimuth axis AZ.

[0055] As shown in FIG. 6B , suppose the orientation of the mirror 103 is adjusted so that the measurement light ML, whose optical axis is offset from the azimuth axis AZ, is incident on the center of the reflector MT. Here, if the measurement light whose optical axis coincides with the azimuth axis AZ is called the ideal measurement light VML, the ideal measurement light VML reflected by the mirror 103, which has been adjusted so that the measurement light ML, whose optical axis is offset from the azimuth axis AZ, is incident on the center of the reflector MT, does not enter the center of the reflector MT. In this case, in order to make the ideal measurement light VML incident on the center of the reflector MT, the mirror 103 must be tilted as shown by the two-dot chain line. When a beam offset occurs, the rotation angle of the mirror 103 about the elevation axis EL when the ideal measurement light VML is incident on the center of the reflector MT does not match the rotation angle of the mirror 103 about the elevation axis EL when the measurement light ML, whose optical axis is offset from the azimuth axis AZ, is incident on the center of the reflector MT, resulting in an angle measurement error α.

[0056] Furthermore, when a beam offset occurs, a distance measurement error also occurs. This point will be explained below. Fig. 7A is a diagram showing an ideal state in which there is no beam offset, and Fig. 7B is a diagram for explaining a distance measurement error in a state in which a beam offset occurs.

[0057] As shown in FIG. 7A, when no beam offset occurs, the optical path length of the reflected light RL from the reflector MT to the mirror 103 is Rc2, and the optical path length from the mirror 103 to the detector 104 is Rc1.

[0058] 7B , when a beam offset occurs, the sum (Rm2+Rm1) of the optical path length Rm2 of the reflected light RL from the reflector MT to the mirror 103 and the optical path length Rm1 from the mirror 103 to the detector 104 does not match the sum (Rc2+Rc1) of the optical path length Rc2 of the reflected light VRL (shown by a dotted line) of the ideal measurement light VML in which no beam offset occurs from the reflector MT to the mirror 103 and the optical path length Rc1 from the mirror 103 to the detector 104. Note that in FIG. 7B , the attitude of the mirror 103 that causes the measurement light ML in which a beam offset occurs to be incident on the reflector MT is indicated by a solid line, and the attitude of the mirror 103 that causes the ideal measurement light VML in which no beam offset occurs to be incident on the reflector MT is indicated by a two-dot chain line.

[0059] In this way, if a beam offset occurs, angle measurement errors and distance measurement errors occur, making it impossible to accurately calculate the position of the measurement target MT. Therefore, in this embodiment, the measurement device 100 is provided with a calibration reflector 107 for calibrating the beam offset (see FIGS. 1B and 4).

[0060] FIG. 8 is a cross-sectional view that schematically shows the optical paths of the calibration light CL that the measurement device 100 irradiates onto the calibration reflector 107 and the calibration reflected light CRL that the measurement device 100 detects from the calibration reflector 107 .

[0061] In the beam offset calibration process, the measurement apparatus 100 irradiates the calibration light CL onto the calibration reflector 107 arranged on the first support unit 105. Specifically, the calibration light CL emitted from the rangefinder 101 is reflected by the mirror 103 and irradiated onto the calibration reflector 107. The calibration reflected light CRL from the calibration reflector 107 is reflected by the mirror 103 and irradiated onto the detector 104. That is, the mirror 103 can reflect the calibration light CL emitted from the emission unit 101a toward the calibration reflector 107 arranged on the first support unit 105, and can also reflect the calibration reflected light CRL from the calibration reflector 107.

[0062] The detector 104 can receive the calibration light CL reflected from the mirror 103. The detector 104 can also receive the calibration reflected light CRL from the calibration reflector 107 via the mirror 103. The detector 104 detects the calibration reflected light CRL from the calibration reflector 107 that is irradiated with the calibration light CL. Calibration reflected light detection information regarding the detection result of the calibration reflected light CRL by the detector 104 is output from the measurement device 100 to the control device 200.

[0063] The calibration reflector 107 is a retroreflective member capable of retroreflecting the calibration light CL. An example of a retroreflective member is a corner cube reflector. Types of corner cube reflectors include a hollow retroreflector and a retroreflector prism. The corner cube reflector may be a corner cube reflective element having a reflection-enhancing coating.

[0064] As a result, when calibration light CL is irradiated onto the calibration reflector 107 via the measurement optical system 102 and the mirror 103, the calibration reflected light CRL from the calibration reflector 107 is incident on the detector 104 via the measurement optical system 102 and the mirror 103.

[0065] Other examples of retroreflective members include a cat's eye, which includes a lens and a mirror placed at the focal point of the lens, and an SMR (Spherically Mounted Retroreflector), which is a combination of three mirrors that intersect with each other at a 90-degree angle.

[0066] The calibration reflector 107 may be at least one of a ball reflector and a cat's eye.

[0067] The calibration reflector 107 is disposed at a position where the measurement light ML does not pass through during a position measurement period for measuring the position of the measurement object MT (i.e., a position measurement period for performing a position measurement operation). As a result, even if the measurement device 100 includes the calibration reflector 107, the measurement light ML reflected by the mirror 103 toward the measurement object MT to measure the position of the measurement object MT is not blocked by the calibration reflector 107. As a result, even if the measurement device 100 includes the calibration reflector 107, the measurement device 100 can appropriately irradiate the measurement light ML onto the measurement object MT and appropriately measure the position of the measurement object MT.

[0068] 8, the calibration reflector 107 is disposed above the first support portion 105, but for example, as indicated by the dotted line, the calibration reflector 107 may be disposed below the first support portion 105. The calibration reflector 107 may be disposed anywhere as long as it rotates in accordance with the movement of the first support portion 105, which rotates about the azimuth axis AZ. Because the calibration reflector 107 is provided on the first support portion 105, when the first support portion 105 rotates about the azimuth axis AZ (i.e., when the mirror 103 rotates about the azimuth axis AZ), the calibration reflector 107 also rotates about the azimuth axis AZ.

[0069] Note that a support member that supports the calibration reflector 107 and is detachable from the first support unit 105 may be attached to the first support unit 105 when the beam offset calibration process is performed. In this case, the support member that supports the calibration reflector 107 can be removed from the first support unit 105 during the position measurement operation.

[0070] 9A is a diagram showing the optical paths of measurement light ML and reflected light RL when the azimuth axis AZ reflected by the mirror 103 is set as a virtual azimuth axis AZ′, and measurement light ML whose optical axis is offset from the azimuth axis AZ is emitted in a state where the virtual azimuth axis AZ′ passes through the center of the reflector MT.

[0071] When measurement light ML whose optical axis is offset from the azimuth axis AZ is emitted with the virtual azimuth axis AZ' passing through the center of the reflector MT, the azimuth axis AZ is the midpoint between the incident position of the measurement light ML and the incident position of the reflected light RL on the detection surface 140 of the detector 104. Note that, in reality, the measurement light ML does not enter the detector 104, and therefore, what is detected by the detector 104 is only the incident position of the reflected light RL.

[0072] In this case, even if the mirror 103 is rotated around the azimuth axis AZ in a state where the virtual azimuth axis AZ' passes through the center of the reflector MT, the center of the image on the detector 104 does not move.

[0073] Therefore, in the beam offset calibration process, the mirror 103 is rotated around the azimuth axis AZ while the calibration reflector 107 is irradiated with the calibration light CL, with the virtual azimuth axis AZ' passing through the center of the reflector MT. The mirror does not have to rotate 360 ​​degrees. The calibration light CL may be irradiated by selecting positions at some rotation angles within 360 degrees.

[0074] As a result, a locus of the incident position of the calibration reflected light CRL is obtained on the detection surface 140 of the detector 104, as shown in FIG. 9B . This can also be said to obtain the results of reception of the calibration reflected light CRL by the detector 104 when the rotation angle of the first support unit 105 around the azimuth axis AZ is a certain rotation angle, and the results of reception of the calibration reflected light CRL by the detector 104 when the rotation angle of the first support unit 105 around the azimuth axis AZ is a different rotation angle. The control device 200 (calibration processing unit 201c) approximates the locus of the incident position of the calibration reflected light CRL with, for example, a circle or a polynomial, and obtains its center SV. In other words, the control device 200 obtains information regarding the position at which the calibration reflected light CRL is received on the detection surface 140 of the detector 104. In addition, if positions at several rotation angles within 360 degrees are selected and the calibration light CL is irradiated, the curve passing through the incident position of the calibration reflected light CRL at each selected position can be approximated with a circle or a polynomial to obtain its center SV.

[0075] In a position detection operation for detecting the position of the measurement object MT using the measurement light ML, the control device 200 controls the attitude of the mirror 103 (the rotation angle of the mirror 103 about the elevation axis EL) so that the reflected light RL from the measurement object MT is incident on the center SV. That is, the control device 200 acquires information about the positional relationship between the optical axis of the measurement optical system 102 that irradiates the calibration light CL and the azimuth axis AZ based on information about the positional relationship, based on information about the positional relationship.

[0076] Hereinafter, the position on the detection surface 140 where the reflected light RL is incident will be referred to as the reflected light return point RP. In FIG. 9B, the center SV is the reflected light return point RP. By making the reflected light RL incident on the reflected light return point RP, it is possible to reduce angle measurement errors and distance measurement errors even when a beam offset occurs. This point will be explained below.

[0077] First, angle measurement errors will be described. Fig. 10A is a diagram showing a state in which the reflected light RL is not incident on the reflected light return point RP. In this case, angle measurement errors occur as described in Fig. 6B.

[0078] 10B shows a state in which the attitude of the mirror 103 (the rotation angle of the mirror 103 about the elevation axis EL) is changed from the state shown in FIG. 10A so that the reflected light RL of the measurement light ML, whose optical axis is offset from the azimuth axis AZ, is incident on the reflected light return point RP. As shown in FIG. 10B, the attitude of the mirror 103 (the rotation angle of the mirror 103 about the elevation axis EL) that causes the reflected light RL to be incident on the reflected light return point RP matches the attitude of the mirror 103 (the rotation angle of the mirror 103 about the elevation axis EL) when the ideal measurement light VML, whose optical axis coincides with the azimuth axis AZ, is incident on the center of the reflector MT. In this way, by causing the reflected light RL of the measurement light ML, whose optical axis is offset from the azimuth axis AZ, to be incident on the reflected light return point RP, angle measurement errors can be reduced.

[0079] Next, distance measurement errors will be described. Fig. 11A is a diagram showing a state in which the reflected light RL of the measurement light ML, whose optical axis is offset from the azimuth axis AZ, is not incident on the reflected light return point RP. In this case, distance errors occur as described in Fig. 7B.

[0080] 11(B) shows a state in which the attitude of the mirror 103 (the rotation angle of the mirror 103 about the elevation axis EL) is changed from the state shown in FIG. 11(A) so that reflected light RL of the measurement light ML, whose optical axis is offset from the azimuth axis AZ, is incident on the reflected light return point RP. In FIG. 11(B), the lengths of the arrows AR11 and AR12 are equal to the lengths of the arrows AR21 and AR22. The lengths of the arrows AR13 and AR14 are equal to the lengths of the arrows AR23 and AR24. The lengths of the arrows AR15 and AR16 are equal to the lengths of the arrows AR25 and AR26.

[0081] As a result, the sum of the optical path length of measurement light ML from detection surface 140 to mirror 103 (the distance between points A and B) and the optical path length of reflected light RL from mirror 103 to detection surface 140 (the distance between points E and PR) becomes equal to the sum of the optical path length of ideal measurement light VML from detection surface 140 to mirror 103 (the distance between points F and G) and the optical path length of reflected light VRL from mirror 103 to detection surface 140 (the distance between points G and F). Furthermore, the sum of the optical path length of measurement light ML from mirror 103 to reflector MT (the distance between points B and C) and the optical path length of reflected light RL from reflector MT to mirror 103 (the distance between points D and E) becomes equal to the sum of the optical path length of ideal measurement light VML from point G to point H and the optical path length of reflected light VRL from point H to point G. The optical path length of the reflected light RL from point C to point D is equal to the sum of the optical path length of the ideal measurement light from point H to point I and the optical path length of the reflected light VRL from point I to point H.

[0082] 11B, when reflected light RL of measurement light ML whose optical axis is offset from the azimuth axis AZ is made incident on the reflected light return point RP, the optical path length from when measurement light ML whose optical axis is offset from the azimuth axis AZ is reflected by the reflector MT and when the reflected light RL is made incident on the detector 104 matches the optical path length from when ideal measurement light VML whose optical axis coincides with the azimuth axis AZ is reflected by the reflector MT and when the reflected light VRL is made incident on the detector 104. In this way, by making reflected light RL incident on the reflected light return point RP determined by the beam offset calibration process described above, it is possible to reduce distance measurement errors.

[0083] (Beam Tilt Calibration Process) Next, the beam tilt calibration process will be described. The beam tilt calibration process is a calibration process related to the positional relationship (tilt) between the optical axis of the measurement optical system 102 that irradiates the calibration light CL and the azimuth axis AZ. FIGS. 12A and 12B are diagrams for explaining beam tilt. As shown in FIGS. 12A and 12B, beam tilt refers to a state in which the optical axis of the measurement light ML is tilted with respect to the azimuth axis AZ. The ideal state is a state in which the optical axis of the measurement light ML is parallel to the azimuth axis AZ.

[0084] As shown in Fig. 12A, when the elevation axis EL is parallel to the X axis, the angle between the azimuth axis AZ and the measurement light ML is referred to as the beam tilt angle around the X axis, and is represented by BTx. Also, as shown in Fig. 12B, when the elevation axis EL is parallel to the Y axis, the angle between the azimuth axis AZ and the measurement light ML is referred to as the beam tilt angle around the Y axis, and is represented by BTy.

[0085] When beam tilt occurs, an angle measurement error occurs. Therefore, a process for calibrating the beam tilt is performed. In the beam tilt calibration process, the calibration light CL is not irradiated onto the calibration reflector 107, and the reflected light of the calibration light CL reflected by the mirror 103 is received by at least one of the rangefinder 101 and the detector 104.

[0086] In the beam tilt calibration process, the control device 200 changes the rotation angle of the mirror 103 about the elevation axis EL, acquires the elevation angle el at which the light intensity (amount of returned light) of the calibration reflected light CRL is maximized when the calibration light CL is directly reflected by the mirror 103 toward the rangefinder 101, and detects the beam tilt angle from the elevation angle el. That is, the control device 200 acquires a light reception result acquired by irradiating the mirror 103 with the calibration light CL when the rotation angle of the mirror 103 about the elevation axis EL is a certain rotation angle, and a light reception result acquired by irradiating the mirror 103 with the calibration light CL when the rotation angle of the mirror 103 about the elevation axis EL is another rotation angle, and acquires the elevation angle el at which the light intensity (amount of returned light) of the calibration reflected light CRL is maximized. Note that information regarding the light intensity of the calibration reflected light CRL may be acquired by at least one of the rangefinder 101 and the detector 104.

[0087] 13A , the initial state is a state in which the azimuth axis AZ and the reflecting surface 130 of the mirror 103 are parallel and the reflecting surface 130 faces the +X direction (rotation angle az about the azimuth axis AZ = 0°), with clockwise rotation being represented by a positive (+) rotation angle and counterclockwise rotation by a negative (−) rotation angle. In this case, when the reflecting surface 130 faces the −Y direction, the rotation angle az about the azimuth axis AZ is +90°, when the reflecting surface 130 faces the −X direction, the rotation angle az about the azimuth axis AZ is +180°, and when the reflecting surface 130 faces the +Y direction, the rotation angle az about the azimuth axis AZ is −90°. When the rotation angle az is 0° and +180°, the elevation axis EL is parallel to the Y axis, and when the rotation angle az is +90° and −90°, the elevation axis EL is parallel to the X axis.

[0088] The elevation angle at which the amount of returned light is maximum when the rotation angle az = a° is defined as el. ａ°The elevation angle el is the angle between the encoder origin and the measurement light ML reflected by the mirror 103. The encoder is an example of a measurement device that measures the elevation angle, and the encoder origin is the reference point of the encoder when measuring the elevation angle (the position where 0° is output).

[0089] As shown in FIG. 13B, when az = +90°, if the angle formed on the YZ plane between the origin of the encoder that detects the elevation angle el and the Z axis (azimuth axis AZ) is OC, the beam tilt angle BTx around the X axis is given by: BTx = el ＋９０° +OC-π (1) As shown in FIG. 13C, when az=-90°, the beam tilt angle BTx around the X axis is expressed as follows: BTx=π-(OC+el －９０° ) (2) From (1) + (2), 2BTx = el ＋９０° -el －９０° BTx = (el ＋９０° -el －９０° ) / 2 (3) In this way, by detecting the elevation angle at which the amount of returned light is maximum at az=+90° and az=−90°, the beam tilt angle BTx around the X axis can be calculated.

[0090] Similarly, by detecting the elevation angle at which the amount of returned light is maximum when az=0° and az=180°, the beam tilt angle BTy about the Y axis can be calculated.

[0091] Also, from (1)-(2), 2OC = (el ＋９０° +el －９０° )-2π OC=(el ＋９０° +el －９０° ) / 2−π (4) and OC can be calculated.

[0092] The control device 200 corrects the equation for calculating the rotation angle of the mirror 103 about the elevation axis EL using the calculated beam tilt angle BTx about the X axis, the calculated beam tilt angle BTy about the Y axis, and the calculated angle OC. Since the position of the measurement object MT is calculated based on distance information about the distance between the rangefinder 101 and the measurement object MT and information about the irradiation direction of the measurement light ML from the mirror 103 (specifically, information about the rotation angle of the mirror 103 about the azimuth axis AZ and the rotation angle of the mirror 103 about the elevation axis EL), correcting the beam tilt can improve the calculation accuracy of the position of the measurement object MT.

[0093] Note that the OC may be calculated at intervals of the rotation angle az smaller than the rotation angle az = 0°, +90°, +180°, and -90° to correct high-frequency axial tilt. Alternatively, the calculation may be speeded up by calculating the OC at intervals of the rotation angle az larger than the rotation angle az.

[0094] (Mirror Tilt Calibration Process) Next, the mirror tilt calibration process will be described. The mirror tilt calibration process is a process for calibrating the attitude of the mirror 103 with respect to a plane perpendicular to the azimuth axis AZ. Even if the mirror 103 is driven so as to be perpendicular to the azimuth axis AZ, the mirror 103 may not be perpendicular to the azimuth axis AZ and may be tilted from the plane perpendicular to the azimuth axis AZ. The mirror tilt is caused by a mirror tilt angle MTA that is generated by the assembly accuracy of the mirror 103 and an elevation tilt angle ETA that is generated by the drive accuracy of the drive system that rotates the mirror 103 around the elevation axis EL.

[0095] If mirror tilt occurs, it is not possible to accurately obtain the rotation angle around the elevation axis EL of the mirror 103. Therefore, a mirror tilt calibration process is executed to calibrate the mirror tilt.

[0096] In the mirror tilt calibration process, the calibration light CL is reflected by the mirror 103 and received by the detector 104 without irradiating the calibration light CL onto the calibration reflector 107 .

[0097] In the mirror tilt calibration process, first, the mirror 103 is driven so that it is perpendicular to the azimuth axis AZ. More specifically, the mirror 103 is driven so that the reflective surface 130 of the mirror 103 is perpendicular to the azimuth axis AZ. If mirror tilt occurs, even if the mirror 103 is driven so that the reflective surface 130 of the mirror 103 is perpendicular to the azimuth axis AZ, the reflective surface 130 of the mirror 103 will not be perpendicular to the azimuth axis AZ, as shown in FIG. 14A. The angle β between the reflective surface 130 of the mirror 103 and a plane PL1 that contains the elevation axis EL and is perpendicular to the azimuth axis AZ is expressed as the sum of the mirror tilt angle MTA and the elevation tilt angle ETA. Note that beam tilt also occurs in the diagram of FIG. 14A.

[0098] Therefore, the mirror 103 is driven so that its reflecting surface 130 is perpendicular to the azimuth axis AZ, and while the calibration light CL continues to be irradiated onto the mirror 103, the mirror 103 is rotated about the azimuth axis AZ to obtain the trajectory of the incident position of the calibration reflected light CRL on the detector 104. That is, information is obtained about the position where the calibration reflected light CRL is received on the detection surface 140 of the detector 104. This can also be said to obtain the result of receiving the calibration reflected light CRL by the detector 104 when the rotation angle of the first support unit 105 about the azimuth axis AZ is a certain rotation angle, and the result of receiving the calibration reflected light CRL by the detector 104 when the rotation angle of the first support unit 105 about the azimuth axis AZ is another rotation angle. More specifically, while the first support part 105 is rotated around the azimuth axis AZ, information regarding the position on the detection surface 140 of the detector 104 where the calibration reflected light CRL is received is acquired.

[0099] 14B shows an example of the locus of the incident position of the calibration reflected light CRL when the mirror 103, which is tilted, is rotated around the azimuth axis AZ while the calibration light CL is irradiated onto the mirror 103. If this locus is approximated by a circle with a radius r, it can be expressed as 2r = a + b. Here, a represents the distance between the azimuth axis AZ and the incident position of the calibration reflected light CRL when the rotation angle az = 0°, and b represents the distance between the azimuth axis AZ and the incident position of the calibration reflected light CRL when the rotation angle az = 180°. If the calibration light CL is irradiated at positions selected from several rotation angles within 360°, the curve passing through the incident position of the calibration reflected light CRL at each selected position can be approximated by a circle.

[0100] 15A is a YZ cross-sectional view illustrating the distance between the azimuth axis AZ and the incident position of the calibration reflected light CRL when the rotation angle az = 0°. In FIG. 15A, a line NL represents the normal to the reflecting surface 130 of the mirror 103.

[0101] If the distance between the detection surface 140 of the detector 104 and the reflecting surface 130 of the mirror 103 on the azimuth axis AZ is L, the mirror tilt angle is MTA, the elevation tilt angle is ETA, and the beam tilt angle is BTA, then a = L × tan (BTA + 2MTA + 2ETA) However, since BTA + 2MTA + 2ETA is actually small, a can be calculated as a = L × (BTA + 2MTA + 2ETA) (5)

[0102] 15B is a YZ cross-sectional view illustrating the distance between the azimuth axis and the incident position of the calibration reflected light CRL when the rotation angle az is 180°. In FIG. 15B, a line NL represents the normal to the reflecting surface 130 of the mirror 103.

[0103] If the distance between the detection surface 140 of the detector 104 and the reflecting surface 130 of the mirror 103 on the azimuth axis AZ is L, the mirror tilt angle is MTA, the elevation tilt angle is ETA, and the beam tilt angle is BTA, then b = L × tan (2MTA + 2ETA - 2BTA) However, since 2MTA + 2ETA - 2BTA is actually small, b can be calculated as b = L × (2MTA + 2ETA - 2BTA) (6)

[0104] Therefore, as shown in FIG. 14B, 2r=a+b=L×4(MTA+ETA), and MTA+ETA=r / 2L (7)

[0105] The mirror tilt angle MTA is caused by the assembly accuracy of the mirror 103 and therefore changes very little over time. Therefore, for example, by substituting the mirror tilt angle MTA measured in the calibration process at the time of shipment into the above equation (7), the elevation tilt angle ETA can be calculated. The control device 200 uses the calculated elevation tilt angle ETA to correct the equation for calculating the horizontal angle of the measurement object MT relative to the measurement device 100. This makes it possible to improve the calculation accuracy of the position of the measurement object MT.

[0106] It is also possible to calibrate higher-order tilt of the azimuth axis AZ from the trajectory of the calibration reflected light CRL.

[0107] As described above in detail, according to the first embodiment, the measurement device 100 is a measurement device that irradiates the measurement object MT with measurement light ML and acquires information about the position of the measurement object MT, and includes an emission unit 101a that emits calibration light CL used to calibrate the measurement device 100, a mirror 103, a first support unit 105 that is rotatable around the azimuth axis AZ and on which the mirror 103 is provided, and a detector 104 that can receive the calibration light CL reflected from the mirror 103. The mirror 103 can reflect the calibration light CL emitted from the emission unit 101a toward a calibration reflector 107 arranged on the first support unit 105, and can reflect the calibration light CL reflected from the calibration reflector 107. The detector 104 can receive the calibration light CL reflected from the calibration reflector 107 arranged on the first support unit 105 via the mirror 103. Beam shift calibration processing, beam tilt calibration processing, and mirror tilt calibration processing can be performed using the results of the detector 104 receiving the reflected light of the calibration light CL from the mirror 103 and the results of the detector 104 receiving the reflected light of the calibration light CL from the calibration reflector 107 via the mirror 103.

[0108] Furthermore, in the first embodiment, the measurement device 100 starts at least one of a beam shift calibration process, a beam tilt calibration process, and a mirror tilt calibration process based on at least one of information about the state of the measurement device 100, information about time, environmental information about at least one of the external environment of the measurement device 100 and the internal environment of the measurement device 100, and an instruction from an external device. This allows various calibration processes to be performed automatically, so that the measurement accuracy of the measurement device 100 can be maintained at a high level.

[0109] In the first embodiment, the reflector provided on the measurement object MT and the calibration reflector 107 may be the same or different. For example, the reflectance, model number, and type (e.g., SMR, cat's eye) of the reflector provided on the measurement object MT may be the same as or different from the reflectance, model number, and type (e.g., SMR, cat's eye) of the calibration reflector 107. Furthermore, the shape of the reflector provided on the measurement object MT and the shape of the calibration reflector 107 may be the same or different. Furthermore, the size of the reflector provided on the measurement object MT and the calibration reflector 107 may be the same or different. By using a small-sized calibration reflector 107, the calibration reflector 107 can be provided within the measurement device 100.

[0110] In the first embodiment, the calibration reflector 107 may be omitted. In this case, the measurement device 100 can perform the mirror tilt calibration process and beam tilt calibration process described above.

[0111] Second Embodiment In the first embodiment, the rangefinder 101 was fixed inside the second support portion 106, but in the second embodiment, the rangefinder 101 is rotatable around the azimuth axis AZ and the elevation axis EL, which is different from the first embodiment. Fig. 16(A) is a perspective view showing an overview of a measurement apparatus 100A according to the second embodiment, and Fig. 16(B) is a diagram showing the schematic configuration of the measurement apparatus 100A according to the second embodiment.

[0112] As shown in FIG. 16B, the measurement apparatus 100A includes a rangefinder 101, a measurement optical system 102, a detector 104, and the like.

[0113] The housing 120 houses the rangefinder 101, the measurement optical system 102, and the detector 104. The housing 120 is supported by a first support unit 150 so as to be rotatable around an elevation axis EL. The first support unit 150 is supported by a second support unit 160 so as to be rotatable around an azimuth axis AZ. This allows the housing 120 to rotate around the azimuth axis AZ and also around the elevation axis EL. The second support unit 160 supports the housing 120 via the first support unit 150 but does not move relative to the housing 120.

[0114] When the housing 120 rotates around the azimuth axis AZ, the rangefinder 101 housed in the housing 120 rotates around the azimuth axis AZ, and when the housing 120 rotates around the elevation axis EL, the rangefinder 101 housed in the housing 120 rotates around the elevation axis EL.

[0115] That is, in the second embodiment, the mirror 103 in the first embodiment is omitted, and by adjusting the rotation angle of the rangefinder 101 around the azimuth axis AZ and the rotation angle around the elevation axis EL, the measurement light ML emitted from the rangefinder 101 is directly irradiated onto the measurement object MT.

[0116] (Beam Offset Calibration Process) Here, also in the measurement apparatus 100A according to the second embodiment, if the optical axis of the measurement light ML is deviated from the azimuth axis AZ, angle measurement errors and distance measurement errors occur.

[0117] In the second embodiment, the measurement apparatus 100A also includes a calibration reflector 107 for calibrating the beam offset, but differs from the first embodiment in that the calibration reflector 107 is disposed on the azimuth axis AZ.

[0118] Fig. 17(A) is a diagram showing an example of the arrangement of the calibration reflector 107 in the second embodiment. In the example of Fig. 17(A), the calibration reflector 107 is fixed, for example, inside the second support part 160 so that its center coincides with the azimuth axis AZ. Note that even if the center of the calibration reflector 107 is deviated from the azimuth axis AZ, it is possible to calibrate the beam offset. Note that although the calibration reflector 107 is arranged on the -Z side of the housing 120 in Fig. 17(A), it may also be arranged on the +Z side of the housing 120.

[0119] In the beam offset calibration process according to the second embodiment, first, as shown in FIG. 17A , the attitude of the housing 120 (the rotation angle around the elevation axis EL) is adjusted so that the optical axis of the calibration light CL is parallel to the azimuth axis AZ, and the calibration light CL is irradiated onto the calibration reflector 107. Then, while the calibration light CL is still irradiated onto the calibration reflector 107, the housing 120 is rotated around the azimuth axis AZ. This causes the rangefinder 101 to rotate around the azimuth axis AZ. Note that the housing 120 does not have to rotate 360 ​​degrees. The calibration light CL may be irradiated by selecting positions at several rotation angles within 360 degrees.

[0120] When the housing 120 is rotated around the azimuth axis AZ while the calibration light CL is being irradiated onto the calibration reflector 107, the locus of the incident position of the calibration reflected light CRL on the detection surface 140 of the detector 104 is acquired, as shown in Fig. 17B. This can also be said to acquire the result of receiving the calibration reflected light CRL by the detector 104 when the rotation angle of the housing 120 around the azimuth axis AZ is a certain rotation angle, and the result of receiving the calibration reflected light CRL by the detector 104 when the rotation angle of the housing 120 around the azimuth axis is a different rotation angle.

[0121] As in the first embodiment, the control device 200 approximates the locus of the incident positions of the calibration reflected light CRL with a circle or a polynomial to determine the center SV of the locus. That is, the control device 200 acquires information about the positions at which the calibration reflected light CRL is received on the detection surface 140 of the detector 104. Note that, if positions at several rotation angles within 360 degrees are selected and the calibration light CL is irradiated, the center SV can be determined by approximating a curve passing through the incident positions of the calibration reflected light CRL at each selected position with a circle or a polynomial.

[0122] When measuring the position of the measurement target MT, the control device 200 adjusts the attitude of the housing 120 (the rotation angle of the housing 120 around the elevation axis EL) so that the reflected light RL of the measurement light ML by the reflector MT is incident on the center SV, as in the first embodiment. This makes it possible to reduce angle measurement errors and distance measurement errors due to beam offset, as in the first embodiment.

[0123] (Beam Tilt Calibration Process) In the second embodiment, since the mirror 103 is omitted, no mirror tilt occurs, but beam tilt does occur. In the second embodiment, as shown in FIG. 18A , the beam tilt is calibrated using a calibration mirror 170 arranged on the azimuth axis AZ. The reflective surface of the calibration mirror 170 is arranged so as to be perpendicular to the azimuth axis AZ. The calibration mirror 170 is fixed, for example, within the second support portion 160.

[0124] The beam tilt angle BTx around the elevation axis EL (X-axis) can be calculated in the same way as in the first embodiment. That is, as shown in FIG. 18A, the rotation angle az of the housing 120 around the azimuth axis is set to +90°, and the housing 120 is rotated around the elevation axis EL (X-axis), and the elevation angle el when the light amount (return light amount) of the calibration light CL reflected by the calibration mirror 170 as the calibration reflected light CRL is maximized is calculated. ＋９０°The control device 200 acquires a light reception result obtained by irradiating the calibration light CL when the rotation angle of the housing 120 around the elevation axis EL is a certain rotation angle, and a light reception result obtained by irradiating the calibration light CL when the rotation angle of the housing 120 around the elevation axis EL is another rotation angle, and acquires the elevation angle el at which the light intensity (returned light intensity) of the calibration reflected light CRL is maximized. In FIG. 18(A), the straight line LN1 indicates the direction in which the measurement light ML (calibration light CL) is emitted when no beam tilt occurs. In addition, OC indicates the angle in the YZ plane between the origin of the encoder that detects the elevation angle el and the Z axis (azimuth axis AZ).

[0125] Next, as shown in FIG. 18B, the rotation angle az of the housing 120 around the azimuth axis is set to −90°, and the housing 120 is rotated around the elevation axis EL (X-axis). The elevation angle el when the amount of calibration reflected light CRL of the calibration light CL by the calibration mirror 170 is maximized is －９０° 18B, a straight line LN1 indicates the direction in which the measurement light ML (calibration light CL) is emitted when no beam tilt occurs. Information regarding the light intensity of the calibration reflected light CRL may be acquired by the rangefinder 101 or the detector 104.

[0126] As a result, similarly to the first embodiment, BTx=(el ＋９０° -el －９０° ) / 2, the beam tilt angle BTx about the elevation axis EL (X-axis) can be calculated. Note that in the second embodiment, since the rangefinder 101 rotates about the azimuth axis AZ, the beam tilt angle BTx about the elevation axis (X-axis) can be calculated by detecting the elevation angle el when the light intensity (returned light intensity) of the calibration reflected light CRL is maximized at positions where the rotation angle az differs by 180°. Therefore, the rotation angle az is not limited to +90° and −90°, and for example, the elevation angle el when the light intensity of the calibration reflected light CRL is maximized may be detected at positions where the rotation angle az is +10° and +190°.

[0127] In the second embodiment, when the rangefinder 101 rotates around the azimuth axis AZ and the elevation axis EL, the measurement optical system 102 and the detector 104 also rotate around the azimuth axis AZ and the elevation axis EL, so the beam tilt angle BTy around the axis (Y axis) perpendicular to the elevation axis EL (X axis) in a plane perpendicular to the azimuth axis AZ cannot be calculated in the same manner as in the first embodiment.

[0128] Therefore, in the second embodiment, the beam tilt angle BTy about the axis (Y axis) perpendicular to the elevation axis EL (X axis) in a plane perpendicular to the azimuth axis AZ is calculated by the following method.

[0129] To calculate the beam tilt angle BTy, as shown in FIG. 19A, the rangefinder 101 (housing 120) is rotated around the elevation axis EL and fixed at the position (angle) where the amount of returned light is maximum.

[0130] Next, while maintaining the orientation of the rangefinder 101, the calibration mirror 170 is irradiated with the calibration light CL, and the rangefinder 101 is rotated around the azimuth axis AZ while the calibration mirror 170 is still irradiated with the calibration light CL. This can be said to obtain the results of reception of the calibration reflected light CRL by the detector 104 when the rotation angle of the housing 120 around the azimuth axis AZ is a certain rotation angle, and the results of reception of the calibration reflected light CRL by the detector 104 when the rotation angle of the housing 120 around the azimuth axis AZ is a different rotation angle. More specifically, while rotating the housing 120 around the azimuth axis AZ, information is obtained regarding the position where the calibration reflected light CRL is received on the detection surface 140 of the detector 104. The rangefinder 101 does not have to rotate 360 ​​degrees. The calibration light CL may be irradiated by selecting positions at several rotation angles within 360 degrees.

[0131] As a result, as shown in FIG. 19D, the locus of the incident position of the calibration reflected light CRL on the detection surface 140 of the detector 104 can be obtained.

[0132] In the locus of the incident position of the calibration reflected light CRL, for example, the radius of a circle having a diameter of a straight line LN3 connecting the position where the calibration reflected light CRL is incident when az = 0° and the position where the calibration reflected light CRL is incident when az = 180° is defined as r ｙ Here, c represents the distance between the azimuth axis AZ and the incident position of the calibration reflected light CRL when the rotation angle az = 0°, and d represents the distance between the azimuth axis AZ and the incident position of the calibration reflected light CRL when the rotation angle az = 180°, then 2r ｙ = c + d.

[0133] 19B is an XZ cross-sectional view illustrating the distance c between the azimuth axis AZ and the incident position of the calibration reflected light CRL when the rotation angle az = 0°. In FIG. 19B, a straight line LN2 indicates the direction of the measurement light ML (calibration light CL) emitted from the rangefinder 101 when no beam tilt occurs. In FIG. 19B, the measurement optical system 102 is not shown.

[0134] 19(B), it is assumed that detector 104 is installed on a plane that passes through the emission point of calibration light CL from rangefinder 101 and is perpendicular to azimuth axis AZ. In this case, the distance c between azimuth axis AZ and the incident position of calibration reflected light CRL is given by c=2×L×tan(ETA+BTy). L is the distance between rangefinder 101 and calibration mirror 170, and ETA represents the tilt angle of rangefinder 101 with respect to elevation axis EL. Since ETA+BTy is actually very small, c=2×L×(ETA+BTy).

[0135] 19C is an XZ cross-sectional view illustrating the distance d between the azimuth axis AZ and the incident position of the calibration reflected light CRL when the rotation angle az is 180°. In FIG. 19C, a straight line LN2 indicates the direction of the measurement light ML (calibration light CL) emitted from the rangefinder 101 when no beam tilt occurs. In FIG. 19C, the measurement optical system 102 is not shown.

[0136] 19(C), it is assumed that detector 104 is installed on a plane that passes through the emission point of calibration light CL from rangefinder 101 and is perpendicular to azimuth axis AZ. In this case, the distance d between azimuth axis AZ and the incident position of calibration reflected light CRL is given by d = 2 × L × tan(ETA + BTy). L is the distance between rangefinder 101 and calibration mirror 170, and ETA represents the tilt angle of rangefinder 101 with respect to elevation axis EL. Since ETA + BTy is actually very small, d = 2 × L × (ETA + BTy).

[0137] Therefore, as shown in FIG. ｙ = c + d = L × 4 (ETA + BTy), and ETA + BTy = r ｙ The tilt angle of the rangefinder 101 with respect to the elevation axis EL can be calculated by various methods, so BTy can be calculated from the above formula.

[0138] In this way, even when the rangefinder 101 rotates around the azimuth axis AZ and around the elevation axis EL, it is possible to calculate the beam tilt angle BTx around the elevation axis EL and the beam tilt angle BTy around an axis perpendicular to the azimuth axis AZ and the elevation axis EL. The calculated beam tilt angles BTx and BTy are used to correct the calculation formula for calculating the position of the measurement target MT from the rotation angle of the rangefinder 101 around the elevation axis EL, thereby improving the calculation accuracy of the position of the measurement target MT.

[0139] If the orthogonality between the azimuth axis AZ and the calibration mirror 170 changes, r ｙ The measurement device 100A is ｙ A mechanism for automatically adjusting the attitude of the calibration mirror 170 so that the difference is minimized may be provided.

[0140] The other configurations are the same as those of the first embodiment, and therefore detailed description thereof will be omitted.

[0141] As described above in detail, according to the second embodiment, the measurement device 100A is a measurement device that irradiates the measurement object MT with measurement light ML and acquires information regarding the position of the measurement object MT, and is equipped with an emission unit 101a that emits calibration light CL used to calibrate the measurement device 100, a calibration reflector 107 or a calibration mirror 170, a detector 104 that can receive reflected light of the calibration light CL from the calibration reflector 107 or the calibration mirror 170, a housing 120 that accommodates the emission unit 101a and the detector 104, and a first support unit 105 that is rotatable around an azimuth axis AZ and supports the housing 120 rotatably around an elevation axis EL that intersects with the azimuth axis AZ. The calibration reflector 107 or the calibration mirror 170 is disposed so as to intersect with the azimuth axis AZ, and the measurement device 100A controls the irradiation direction of the measurement light ML based on the light reception result of the calibration light CL reflected by the calibration reflector 107 or the calibration mirror 170 received by the detector 104. This makes it possible to perform a beam shift calibration process or a beam tilt calibration process, thereby improving the measurement accuracy of the measurement device 100A.

[0142] In the second embodiment, the example in which the calibration reflector 107 or the calibration mirror 170 is provided inside the second support portion 160 has been described, but the present invention is not limited to this.

[0143] 20A is a diagram showing another example of the arrangement of the calibration reflector 107 or the calibration mirror 170. In Fig. 20A, the measurement apparatus 100A has a support 161 that extends upward from the second support unit 160 and intersects with the azimuth axis AZ. The support 161 supports the calibration reflector 107 or the calibration mirror 170 above the first support unit 150 so that the calibration reflector 107 or the calibration mirror 170 is positioned on the azimuth axis AZ. In this manner, the calibration reflector 107 or the calibration mirror 170 may be arranged above the first support unit 150.

[0144] 20B is a diagram showing another example of the arrangement of the calibration reflector 107 and the calibration mirror 170. In the example shown in FIG. 20B , one of the calibration reflector 107 and the calibration mirror 170 is provided either inside the second support unit 160 or on the support column 161, and the other of the calibration reflector 107 and the calibration mirror 170 is provided either inside the second support unit 160 or on the support column 161. For example, the calibration reflector 107 is provided on the support column 161, and the calibration mirror 170 is provided inside the second support unit 160. In this way, when performing the beam offset calibration process, the posture of the housing 120 is changed to irradiate the calibration light CL onto the calibration reflector 107, and when performing the beam tilt calibration process, the posture of the housing 120 is changed to irradiate the calibration light CL onto the calibration mirror 170.

[0145] (Self-Check) In the first and second embodiments, various calibration processes are performed at predetermined timings, but the control device 200 may be configured to issue a warning if predetermined conditions are satisfied at the timing when various calibration processes are performed. That is, the control device 200 may output a warning based on the result of reception of the calibration reflected light CRL by at least one of the detector 104 and the rangefinder 101.

[0146] For example, the control device 200 stores the values ​​of various parameters (e.g., the radius of the trajectory of the incident position of the calibration reflected light CRL on the detection surface 140 of the detector 104, the beam tilt angle BTx, the beam tilt angle BTy, etc.) acquired when various calibration processes are performed, as well as residuals in the approximation process when calculating the various parameters, in a memory unit not shown, together with the timing at which the various calibration processes are performed.

[0147] 21 is a graph showing the transition of the residual error in the approximation process when the locus of the incident positions of the calibration reflected light CRL is approximated by a circle to find the center SV of the locus of the incident positions of the calibration reflected light CRL (see FIG. 9B ) in the beam offset calibration process of the first embodiment, for example. In FIG. 21 , the horizontal axis represents the elapsed time, and the vertical axis represents the residual error.

[0148] As the residual error in the approximation process increases, the approximation accuracy decreases, thereby reducing the accuracy of the beam offset calibration. Therefore, for example, at timing T1 when the residual error exceeds threshold TV1, the control device 200 may indicate a risk of a decrease in the accuracy of the beam offset calibration by displaying a warning on a display screen or outputting a warning sound from a speaker. Furthermore, the control device 200 may stop the measurement of the position of the measurement object MT by the measurement device 100 at timing T2 when the residual error exceeds threshold TV2, which is greater than threshold TV1. The residual error exceeding threshold TV2 indicates a further decrease in the approximation accuracy. Therefore, even if the reflected light RL is incident on the center SV calculated based on such an approximation result, it may not be possible to sufficiently correct the angle measurement error and distance measurement error, and the position of the measurement object MT may not be accurately measured. Therefore, when the residual error exceeds threshold TV2, the control device 200 stops the measurement of the position of the measurement object MT by the measurement device 100. In this case, the control device 200 may display a message on the display device or may communicate this to the user by voice, urging the user to request repairs from the manufacturer.

[0149] Fig. 22 is a diagram showing an application example of the measurement device 100 or the measurement device 100A. In Fig. 22, the reflector MT is provided at the tip of the robot hand RBT. In this way, by providing the reflector MT at the tip of the robot hand RBT and irradiating the measurement light ML from the measurement device 100 or the measurement device 100A onto the reflector MT, the position of the robot hand RBT can be measured.

[0150] The above-described embodiment is a preferred example of the present invention, but the present invention is not limited to this and can be modified in various ways without departing from the spirit of the present invention.

[0151] The following supplementary notes are further disclosed regarding the above-described embodiments: [Supplementary Note 1] A measurement device that irradiates a measurement object with light and acquires information regarding the position of the measurement object, comprising: an emission device that emits the light; a support member that is rotatable about a first rotation axis and has a first reflecting member provided thereon; the first reflecting member that reflects the light emitted from the emission device toward a second reflecting member that is arranged on the support member and reflects the light reflected from the second reflecting member; and a detector that receives the light reflected from the second reflecting member, wherein the measurement device controls the irradiation direction of the light based on a result of reception of the light by the detector. [Supplementary Note 2] A calibration method for a measurement device that irradiates a measurement object with measurement light and acquires information regarding the position of the measurement object, the calibration method including: emitting calibration light used for calibrating the measurement device from an emission device; reflecting the calibration light emitted from the emission device toward a second reflecting member arranged on a support member rotatable about a first rotation axis by a first reflecting member provided on the support member; and receiving the calibration light reflected from the second reflecting member arranged on the support member by a detector via the first reflecting member. [Supplementary Note 3] The calibration method according to Supplementary Note 2, further including setting a reception result of the reflected light of the calibration light by the detector as a first light reception result, and controlling the irradiation direction of the measurement light based on the first light reception result. [Supplementary Note 4] The calibration method according to Supplementary Note 3, wherein the first light reception result is acquired while rotating the support member about the first rotation axis. [Supplementary Note 5] The calibration method according to any one of Supplementary Note 2 to Supplementary Note 4, further comprising: using the detector as a first detector; receiving the reflected light of the calibration light reflected by the first reflecting member by at least one of the first detector and a second detector different from the first detector as a second light-receiving result; and controlling the irradiation direction of the measurement light based on the second light-receiving result.[Supplementary Note 6] The calibration method according to Supplementary Note 5, wherein the second light reception result includes a third light reception result of reflected light of the calibration light received by the first detector and reflected by the first reflecting member, and the third light reception result includes a light reception result obtained by irradiating the calibration light when the rotation angle of the support member about the first rotation axis is a first rotation angle, and a light reception result obtained by irradiating the calibration light when the rotation angle of the support member about the first rotation axis is a second rotation angle different from the first rotation angle. [Supplementary Note 7] The calibration method according to Supplementary Note 6, wherein the third light reception result is obtained while rotating the support member about the first rotation axis. [Supplementary Note 8] The calibration method according to any one of Supplementary Note 5 to Supplementary Note 7, wherein the second light receiving result includes a fourth light receiving result in which reflected light of the calibration light is detected by at least one of the first detector and the second detector, and the fourth light receiving result includes a light receiving result obtained by irradiating the calibration light when the rotation angle of the first reflecting member about the second rotation axis is a third rotation angle, and a light receiving result obtained by irradiating the calibration light when the rotation angle of the first reflecting member about the second rotation axis is a fourth rotation angle different from the third rotation angle. [Supplementary Note 9] A measurement device that irradiates a measurement object with measurement light and acquires information regarding the position of the measurement object, comprising: an emission device that emits calibration light used to calibrate the measurement device, a first reflecting member, a support member that is rotatable about a first rotation axis and on which the first reflecting member is provided, and a detector that can receive the calibration light reflected from the first reflecting member, wherein the measurement device controls the irradiation direction of the measurement light based on a light reception result of the reflected light of the calibration light by the detector. [Supplementary Note 10] The measurement device according to Supplementary Note 9, wherein the detector is a first detector, and a result of receiving the reflected light of the calibration light reflected by the first reflecting member by at least one of the first detector and a second detector different from the first detector is set as a first light reception result, and the irradiation direction of the measurement light is controlled based on the first light reception result. [Supplementary Note 11] The measurement device according to Supplementary Note 10, wherein the first light reception result is a light reception result of reflected light of the calibration light that is reflected by the first reflecting member without irradiating the calibration light onto another reflecting member.[Supplementary Note 12] The measurement device according to Supplementary Note 10 or Supplementary Note 11, wherein the first light reception result includes a second light reception result of reflected light of the calibration light reflected by the first reflecting member and received by the first detector, and the second light reception result includes a light reception result obtained by irradiating the calibration light when the rotation angle of the support member about the first rotation axis is a first rotation angle, and a light reception result obtained by irradiating the calibration light when the rotation angle of the support member about the first rotation axis is a second rotation angle different from the first rotation angle. [Supplementary Note 13] The measurement device according to Supplementary Note 12, wherein the second light reception result is obtained while rotating the support member about the first rotation axis. [Supplementary Note 14] The measurement device according to Supplementary Note 12 or Supplementary Note 13, wherein the second light reception result includes information on a position at which the reflected light of the calibration light is received on a detection surface of the first detector. [Supplementary Note 15] The measurement device according to Supplementary Note 14, wherein information about an attitude of the first reflecting member with respect to a plane orthogonal to the first rotation axis is acquired based on information about a position where reflected light of the calibration light is received on the detection surface of the second light receiving result, and the irradiation direction of the measurement light is controlled based on the information about the attitude. [Supplementary Note 16] The measurement device according to any of Supplementary Notes 10 to 15, wherein the calibration includes calibration of the attitude of the first reflecting member with respect to a plane orthogonal to the first rotation axis. [Supplementary Note 17] The measurement device according to any of Supplementary Notes 10 to 16, wherein the support member supports the first reflecting member rotatably around a second rotation axis intersecting the first rotation axis. [Supplementary Note 18] The measurement device according to Supplementary Note 17, wherein the first light receiving result includes a third light receiving result in which reflected light of the calibration light is detected by at least one of the first detector and the second detector, and the third light receiving result includes a light receiving result obtained by irradiating the calibration light when the rotation angle of the first reflecting member about the second rotation axis is a third rotation angle, and a light receiving result obtained by irradiating the calibration light when the rotation angle of the first reflecting member about the second rotation axis is a fourth rotation angle different from the third rotation angle. [Supplementary Note 19] The measurement device according to Supplementary Note 18, wherein the third light receiving result includes information on the amount of reflected light of the calibration light by at least one of the first detector and the second detector.[Supplementary Note 20] The measurement device according to Supplementary Note 19, wherein information on a positional relationship between an optical axis of an optical system that irradiates the calibration light and the first rotation axis is acquired based on information on the light amount in the third light reception result, and the irradiation direction of the measurement light is controlled based on the information on the positional relationship. [Supplementary Note 21] The measurement device according to any of Supplements 17 to 20, wherein the calibration includes calibration of a positional relationship between the optical axis of the optical system that irradiates the calibration light and the first rotation axis. [Supplementary Note 22] The measurement device according to any of Supplements 10 to 21, wherein the second detector is capable of receiving the measurement light via the first reflecting member, and wherein information on a position of the measurement object is acquired based on a result of receiving the measurement light by the second detector. [Supplementary Note 23] The measurement device according to any of Supplements 9 to 22, wherein the calibration of the measurement device is started based on at least one of information on a state of the measurement device, information on time, environmental information on at least one of an environment external to the measurement device and an environment internal to the measurement device, and an instruction from an external device. [Supplementary Note 24] The measurement device according to any one of Supplementary Notes 9 to 23, comprising an output device that outputs a warning based on the light receiving result. [Supplementary Note 25] The measurement device according to any one of Supplementary Notes 9 to 23, wherein the first reflecting member reflects at least one of the measurement light and the calibration light. [Supplementary Note 26] The measurement device according to any one of Supplementary Notes 9 to 25, wherein the emission device is capable of irradiating the measurement light to a second reflecting member provided on the measurement object. [Supplementary Note 27] A measurement device that irradiates a measurement object with measurement light and acquires information related to the position of the measurement object, comprising: an emission device that emits calibration light used to calibrate the measurement device; a first reflecting member; a detector that can receive reflected light of the calibration light from the first reflecting member; and a housing unit that houses the emission device and the detector and is rotatable around a first rotation axis and a second rotation axis that intersects with the first rotation axis, wherein the first reflecting member is arranged to intersect with the first rotation axis, and the measurement device controls the irradiation direction of the measurement light based on a light reception result of the reflected light of the calibration light reflected by the first reflecting member received by the detector.[Supplementary Note 28] The measurement device according to Supplementary Note 27, wherein the calibration includes calibration of the irradiation direction of the measurement light. [Supplementary Note 29] The measurement device according to Supplementary Note 27 or Supplementary Note 28, wherein a light reception result of reflected light of the calibration light by the detector is set as a first light reception result, and wherein the irradiation direction of the measurement light is controlled based on the first light reception result. [Supplementary Note 30] The measurement device according to Supplementary Note 29, wherein the first light reception result is acquired while rotating the container about the first rotation axis. [Supplementary Note 31] The measurement device according to Supplementary Note 29 or Supplementary Note 30, wherein the first light reception result includes a light reception result when the rotation angle of the container about the first rotation axis is a first rotation angle, and a light reception result when the rotation angle of the container about the first rotation axis is a second rotation angle different from the first rotation angle. [Supplementary Note 32] The measurement device according to any one of Supplementary Notes 29 to 31, wherein the first light-reception result includes information about a position where the reflected light of the calibration light is received on a detection surface of the detector. [Supplementary Note 33] The measurement device according to Supplementary Note 32, wherein first information about a positional relationship between an optical axis of an optical system that irradiates the calibration light and the first rotation axis is acquired based on information about a position where the reflected light of the calibration light is received on the detection surface, and the irradiation direction of the measurement light is controlled based on the first information about the positional relationship. [Supplementary Note 34] The measurement device according to any one of Supplementary Notes 27 to 33, wherein the detector is a first detector, and a result of receiving the reflected light of the calibration light reflected by the first reflecting member by at least one of the first detector and a second detector different from the first detector is set as a second light-reception result, and the irradiation direction of the measurement light is controlled based on the second light-reception result. [Supplementary Note 35] The measuring device described in Supplementary Note 34, wherein the second light receiving result includes a third light receiving result of reflected light of the calibration light received by the first detector and reflected by the first reflecting member, and the third light receiving result includes a light receiving result obtained by irradiating the calibration light when the rotation angle of the container unit about the first rotation axis is a third rotation angle, and a light receiving result obtained by irradiating the calibration light when the rotation angle of the container unit about the first rotation axis is a fourth rotation angle different from the third rotation angle.[Supplementary Note 36] The measurement device according to Supplementary Note 35, wherein the third light-reception result is acquired while rotating the container around the first rotation axis. [Supplementary Note 37] The measurement device according to Supplementary Note 35 or Supplementary Note 36, wherein the third light-reception result includes information about a position where reflected light of the calibration light is received on the detection surface of the first detector. [Supplementary Note 38] The measurement device according to Supplementary Note 37, wherein second information about a positional relationship between an optical axis of an optical system that irradiates the calibration light and the first rotation axis in a first plane orthogonal to the second rotation axis is acquired based on information about the position where reflected light of the calibration light is received on the detection surface of the first detector in the third light-reception result, and controls the irradiation direction of the measurement light based on the second information about the positional relationship. [Supplementary Note 39] The measurement device according to any of Supplements 34 to 38, wherein the calibration includes calibration of a positional relationship between an optical axis of the optical system that irradiates the calibration light and a direction orthogonal to the first rotation axis in a first plane orthogonal to the second rotation axis. [Supplementary Note 40] The measurement device according to any one of Supplementary Notes 34 to 39, wherein the second light receiving result includes a fourth light receiving result in which reflected light of the calibration light is detected by at least one of the first detector and the second detector, and the fourth light receiving result includes a light receiving result obtained by irradiating the calibration light when the rotation angle of the container about the second rotation axis is a fifth rotation angle, and a light receiving result obtained by irradiating the calibration light when the rotation angle of the container about the second rotation axis is a sixth rotation angle different from the fifth rotation angle. [Supplementary Note 41] The measurement device according to Supplementary Note 40, wherein the fourth light receiving result includes information on the amount of reflected light of the calibration light by at least one of the first detector and the second detector. [Supplementary Note 42] The measurement device according to Supplementary Note 41, wherein third information regarding a positional relationship between an optical axis of an optical system that irradiates the calibration light in a second plane orthogonal to the first plane and the first rotation axis is acquired based on information regarding the light amount in the fourth light reception result, and the irradiation direction of the measurement light is controlled based on the third information regarding the positional relationship. [Supplementary Note 43] The measurement device according to any of Supplementary Notes 34 to 42, wherein the second detector is capable of receiving the measurement light, and information regarding a position of the measurement object is acquired based on a result of receiving the measurement light by the second detector.[Supplementary Note 44] The measurement device according to any one of Supplementary Notes 27 to 43, wherein the calibration of the measurement device is started based on at least one of information about the state of the measurement device, information about time, environmental information about at least one of an environment external to the measurement device and an environment internal to the measurement device, and an instruction from an external device. [Supplementary Note 45] The measurement device according to any one of Supplementary Notes 27 to 44, comprising an output device that outputs a warning based on the light receiving result. [Supplementary Note 46] The measurement device according to any one of Supplementary Notes 27 to 45, wherein the emission device is capable of irradiating the measurement light onto a second reflecting member provided on the measurement object, and the second reflecting member and the first reflecting member have the same shape. [Supplementary Note 47] The measurement device according to any one of Supplementary Notes 27 to 45, wherein the emission device is capable of irradiating the measurement light onto a second reflecting member provided on the measurement object, and the second reflecting member and the first reflecting member have different sizes. [Supplementary Note 48] The measurement device according to any one of Supplementary Note 27 to Supplementary Note 47, further comprising a support part that supports the housing part and does not move relative to the housing part, and the first reflecting member is provided on the support part.

[0152] 100, 100A Measuring device 200 Control device 103 Mirror 104 Detector 107 Calibration reflector 170 Calibration mirror 105 First support portion 150 First support portion

Claims

A measurement device that irradiates a measurement object with measurement light and acquires information about the position of the measurement object, an emission device that emits calibration light used to calibrate the measurement device; A first reflecting member; a support member rotatable about a first rotation axis and provided with the first reflecting member; a detector capable of receiving the calibration light reflected from the first reflecting member; Equipped with the first reflecting member is capable of reflecting the calibration light emitted from the emission device toward a second reflecting member disposed on the support member, and is capable of reflecting the calibration light reflected by the second reflecting member; the detector is capable of receiving, via the first reflecting member, the calibration light reflected from the second reflecting member disposed on the support member; Measuring equipment. 　 the calibration includes calibration related to the irradiation direction of the measurement light; The measurement device according to claim 1 . 　 a light reception result of the reflected light of the calibration light by the detector is defined as a first light reception result; The irradiation direction of the measurement light is controlled based on the first light receiving result. The measuring device according to claim 1 or 2. 　 the first light receiving result is acquired while rotating the support member around the first rotation axis; The measurement device according to claim 3 . 　 the first light reception result includes a light reception result when a rotation angle of the support member about the first rotation axis is a first rotation angle, and a light reception result when the rotation angle of the support member about the first rotation axis is a second rotation angle different from the first rotation angle. The measuring device according to claim 3 or 4. 　 the first light receiving result includes information about a position on the detection surface of the detector where the reflected light of the calibration light is received; The measuring device according to any one of claims 3 to 5. 　 acquiring first information regarding a positional relationship between an optical axis of an optical system that irradiates the calibration light and the first rotation axis based on information regarding a position where the reflected light of the calibration light is received on the detection surface, and controlling the irradiation direction of the measurement light based on the first information regarding the positional relationship; The measurement device according to claim 6. 　 the calibration includes calibration of a positional relationship between an optical axis of an optical system that irradiates the calibration light and the first rotation axis; The measuring device according to any one of claims 1 to 7. 　 the detector is defined as a first detector, and a result of receiving the reflected light of the calibration light reflected by the first reflecting member by at least one of the first detector and a second detector different from the first detector is defined as a second light receiving result; The irradiation direction of the measurement light is controlled based on the second light receiving result. The measuring device according to any one of claims 1 to 8. 　 the second light receiving result is a light receiving result of reflected light of the calibration light reflected by the first reflecting member without irradiating the calibration light onto the second reflecting member; The measurement device according to claim 9. 　 the second light receiving result includes a third light receiving result of reflected light of the calibration light received by the first detector and reflected by the first reflecting member, the third light reception result includes a light reception result obtained by irradiating the calibration light when the rotation angle of the support member around the first rotation axis is a third rotation angle, and a light reception result obtained by irradiating the calibration light when the rotation angle of the support member around the first rotation axis is a fourth rotation angle different from the third rotation angle. The measuring device according to claim 9 or 10. 　 the third light receiving result is acquired while rotating the support member around the first rotation axis; The measurement device according to claim 11. 　 the third light reception result includes information about a position on the detection surface of the first detector where the reflected light of the calibration light is received. The measuring device according to claim 11 or 12. 　 acquiring information about an attitude of the first reflecting member with respect to a plane perpendicular to the first rotation axis based on information about a position where the reflected light of the calibration light is received on the detection surface of the third light receiving result, and controlling the irradiation direction of the measurement light based on the information about the attitude; The measurement device according to claim 13. the calibration includes calibration of an attitude of the first reflecting member with respect to a plane perpendicular to the first rotation axis; The measurement device according to any one of claims 9 to 14. 　 the support member supports the first reflecting member rotatably around a second rotation axis intersecting the first rotation axis; The measuring device according to any one of claims 9 to 15. 　 the second light receiving result includes a fourth light receiving result in which reflected light of the calibration light is detected by at least one of the first detector and the second detector; the fourth light reception result includes a light reception result obtained by irradiating the calibration light when the rotation angle of the first reflecting member around the second rotation axis is a fifth rotation angle, and a light reception result obtained by irradiating the calibration light when the rotation angle of the first reflecting member around the second rotation axis is a sixth rotation angle different from the fifth rotation angle. The measurement device according to claim 16. 　 the fourth light receiving result includes information about the amount of reflected light of the calibration light at at least one of the first detector and the second detector; The measurement device according to claim 17. 　 acquiring second information on a positional relationship between an optical axis of an optical system that irradiates the calibration light and the first rotation axis based on information on the light amount in the fourth light receiving result, and controlling the irradiation direction of the measurement light based on the second information on the positional relationship; The measurement device according to claim 18. 　 the calibration includes calibration of a positional relationship between an optical axis of an optical system that irradiates the calibration light and the first rotation axis; The measurement device according to any one of claims 9 to 19. 　 the second detector is capable of receiving the measurement light via the first reflecting member, acquiring information about the position of the measurement object based on a result of receiving the measurement light by the second detector; The measuring device according to any one of claims 18 to 20. 　 The calibration of the measurement device is started based on at least one of information on a state of the measurement device, information on time, environmental information on at least one of an environment outside the measurement device and an environment inside the measurement device, and an instruction from an external device. The measurement device according to any one of claims 1 to 21. 　 an output device that outputs a warning based on the result of reception of the reflected light of the calibration light by the detector; The measurement device according to any one of claims 1 to 22. 　 the first reflecting member reflects at least one of the measurement light and the calibration light; The measurement device according to any one of claims 1 to 23. 　 the emission device is capable of irradiating the measurement light onto a third reflecting member provided on the measurement object, The shape of the third reflecting member is the same as the shape of the second reflecting member. The measurement device according to any one of claims 1 to 24. 　 the emission device is capable of irradiating the measurement light onto a third reflecting member provided on the measurement object, The third reflecting member and the second reflecting member have different sizes. The measurement device according to any one of claims 1 to 24.

1. A method for calibrating a measurement device that irradiates a measurement object with measurement light and acquires information about a position of the measurement object, comprising: emitting calibration light from an emitting device to be used for calibrating the measurement device; reflecting the calibration light emitted from the emission device toward a second reflecting member disposed on a support member rotatable around a first rotation axis by a first reflecting member provided on the support member; receiving the calibration light reflected from the second reflecting member disposed on the support member with a detector via the first reflecting member; A calibration method including: 　 a light reception result of the reflected light of the calibration light by the detector is set as a first light reception result, and an irradiation direction of the measurement light is controlled based on the first light reception result.

28. The calibration method of claim 27. 　 A measurement device that irradiates a measurement object with measurement light and acquires information about the position of the measurement object, an emission device that emits calibration light used to calibrate the measurement device; A first reflecting member; a support member rotatable about a first rotation axis and provided with the first reflecting member; a detector capable of receiving the calibration light reflected from the first reflecting member; Equipped with controlling the irradiation direction of the measurement light based on the result of reception of the reflected light of the calibration light by the detector; Measuring equipment. 　 the detector is defined as a first detector, and a result of receiving the reflected light of the calibration light reflected by the first reflecting member by at least one of the first detector and a second detector different from the first detector is defined as a first light receiving result; controlling the irradiation direction of the measurement light based on the first light receiving result; 30. The measurement device of claim 29. 　 the first light receiving result is a light receiving result of reflected light of the calibration light reflected by the first reflecting member without irradiating the calibration light onto another reflecting member; The measurement device of claim 30.

1. A method for calibrating a measurement device that irradiates a measurement object with measurement light and acquires information about a position of the measurement object, comprising: emitting calibration light from an emitting device to be used for calibrating the measurement device; reflecting the calibration light emitted from the emission device toward a detector by a first reflecting member provided on a support member rotatable around a first rotation axis; The calibration light reflected from the first reflecting member can be received by the detector; controlling the irradiation direction of the measurement light based on a result of reception of the reflected light of the calibration light by the detector; A calibration method including: 　 the detector is a first detector, a result of receiving the reflected light of the calibration light reflected by the first reflecting member by at least one of the first detector and a second detector different from the first detector is set as a first light receiving result, and an irradiation direction of the measurement light is controlled based on the first light receiving result.

33. The calibration method of claim 32. 　 A measurement device that irradiates a measurement object with measurement light and acquires information about the position of the measurement object, an emission device that emits calibration light used to calibrate the measurement device; A first reflecting member; a detector capable of receiving the calibration light reflected from the first reflecting member; a housing section that houses the injection device and the detector and is rotatable around a first rotation axis and a second rotation axis that intersects with the first rotation axis; Equipped with the first reflecting member is disposed so as to intersect with the first rotation axis, controlling the irradiation direction of the measurement light based on a light reception result of the calibration light reflected by the first reflecting member and received by the detector; Measuring equipment. 　 the calibration includes calibration related to the irradiation direction of the measurement light; 35. The measurement device of claim 34. 　 a light reception result of the reflected light of the calibration light by the detector is defined as a first light reception result; controlling the irradiation direction of the measurement light based on the first light receiving result; The measuring device according to claim 34 or claim 35. 　 The first light receiving result is acquired while rotating the storage unit around the first rotation axis.

37. The measurement device of claim 36. 　 the calibration includes calibration of a positional relationship between an optical axis of an optical system that irradiates the calibration light and the first rotation axis; 38. The measurement device according to any one of claims 34 to 37. 　 the detector is defined as a first detector, and a result of receiving the reflected light of the calibration light reflected by the first reflecting member by at least one of the first detector and a second detector different from the first detector is defined as a second light receiving result; controlling the irradiation direction of the measurement light based on the second light receiving result; 39. The measurement device according to any one of claims 34 to 38. 　 the second light receiving result includes a third light receiving result of reflected light of the calibration light received by the first detector and reflected by the first reflecting member, the third light receiving result includes a light receiving result obtained by irradiating the calibration light when the rotation angle of the storage unit around the first rotation axis is a third rotation angle, and a light receiving result obtained by irradiating the calibration light when the rotation angle of the storage unit around the first rotation axis is a fourth rotation angle different from the third rotation angle.

40. The measurement device of claim 39. 　 the second light receiving result includes a fourth light receiving result in which reflected light of the calibration light is detected by at least one of the first detector and the second detector; The fourth light reception result includes a light reception result obtained by irradiating the calibration light when the rotation angle of the container about the second rotation axis is a fifth rotation angle, and a light reception result obtained by irradiating the calibration light when the rotation angle of the container about the second rotation axis is a sixth rotation angle different from the fifth rotation angle.

40. The measurement device of claim 39. 　 the calibration includes calibration of a positional relationship between an optical axis of an optical system that irradiates the calibration light and the first rotation axis; 42. The measuring device according to any one of claims 39 to 41. 　 a support part that supports the storage part and does not move relative to the storage part, the first reflecting member is provided on an attachment portion that faces the support portion across the accommodation portion in a direction parallel to the first rotation axis; 43. The measurement device according to any one of claims 34 to 42. 　 a support part that supports the storage part and does not move relative to the storage part, the first reflecting member includes a reflector that reflects the incident calibration light in a direction parallel to and opposite to the incident direction, and a flat mirror; one of the reflector and the mirror is provided on the support; The other of the reflector and the mirror is provided on an attachment part facing the support part with the accommodation part interposed therebetween.

44. The measuring device according to any one of claims 34 to 43.

1. A method for calibrating a measurement device that irradiates a measurement object with measurement light and acquires information about a position of the measurement object, comprising: emitting calibration light from an emitting device to be used for calibrating the measurement device; receiving the calibration light reflected from the first reflecting member by a detector accommodated in a housing portion rotatable about a first rotation axis and about a second rotation axis intersecting the first rotation axis and housing the emission device; controlling the irradiation direction of the measurement light based on a light reception result of the calibration light reflected by the first reflecting member and received by the detector; Including, The first reflecting member is disposed so as to intersect with the first rotation axis. Calibration methods. 　 a light reception result of the reflected light of the calibration light by the detector is set as a first light reception result, and an irradiation direction of the measurement light is controlled based on the first light reception result.

46. ​​The calibration method of claim 45.

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