Calibration system for non-contact speedometer and calibration method for non-contact speedometer

Abstract

To provide a new system capable of calibrating a noncontact velocity meter.SOLUTION: A calibration system for a noncontact velocity meter includes: a movable mobile device 20 on which a noncontact velocity meter 10 to be calibrated is arranged; a speedometer 30 for reference that measures the speed of the noncontact velocity meter 10 moving together with the mobile device 20 as the speed for reference; and a calibration signal generation section 301 that generates a calibration signal for calibrating the measured speed of the noncontact velocity meter 10 on the basis of the speed for reference and the measured speed measured by the noncontact velocity meter 10 moving together with the mobile device 20.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a system and method for calibrating a non-contact speed meter. [Background technology]

[0002] A non-contact speedometer can measure the speed of an object without contacting it, and is used, for example, to measure the transport speed of a film being wound onto a roll. Methods for calibrating a non-contact speedometer have been proposed to maintain its accuracy (see, for example, Patent Documents 1 to 3). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 59-126976 [Patent Document 2] Japanese Patent Application Publication No. 9-113526 [Patent Document 3] Japanese Patent Application Publication No. 2017-173216 Summary of the Invention [Problem to be solved by the invention]

[0004] SUMMARY OF THE INVENTION An object of the present invention is to provide a new system and method for calibrating a non-contact speed meter. [Means for solving the problem]

[0005] A calibration system for a non-contact speedometer according to an aspect of the present invention includes a movable mobile device on which a non-contact speedometer to be calibrated is placed, a reference speedometer that measures the speed of the non-contact speedometer that moves with the mobile device as a reference speed, and a calibration signal generation unit that generates a calibration signal for calibrating the measured speed of the non-contact speedometer based on the measured speed measured by the non-contact speedometer that moves with the mobile device and the reference speed.

[0006] The calibration system for the non-contact speed meter may further include a measurement object of the non-contact speed meter that is parallel to the direction of movement of the mobile device, and the non-contact speed meter may irradiate light onto the measurement object and measure the measurement speed based on the light reflected from the measurement object.

[0007] In the above-described calibration system for a non-contact speedometer, a reference speedometer may be disposed opposite the non-contact speedometer, and the reference speedometer may irradiate light onto the non-contact speedometer and measure the reference speed based on the light reflected from the non-contact speedometer.

[0008] In the above-described calibration system for a non-contact speedometer, a reference speedometer may be arranged opposite the non-contact speedometer, the reference speedometer may irradiate light onto the non-contact speedometer, and measure the reference speed based on the light reflected from the non-contact speedometer, and the non-contact speedometer, reference speedometer, and object to be measured may be arranged so that the light reflected from the object to the non-contact speedometer and the light reflected from the non-contact speedometer to the reference speedometer form a right angle.

[0009] In the above-described non-contact speedometer calibration system, the reference speedometer may be arranged in the direction of movement of the moving device or in the direction opposite to the direction of movement.

[0010] The above-described calibration system for a non-contact speedometer may further include a calibration signal transmitting unit for transmitting a calibration signal to the non-contact speedometer.

[0011] The calibration system for the non-contact speed meter may be configured such that the calibration signal causes the measured speed to approach a reference speed.

[0012] In the above-described non-contact speed meter calibration system, a time stamp may be added to the measured speed. Also, a time stamp may be added to the reference speed. The calibration signal generation unit may compare the measured speed and the reference speed, which are transmitted at the same time, based on the time stamp.

[0013] Furthermore, a method for calibrating a non-contact speedometer according to an aspect of the present invention includes placing the non-contact speedometer to be calibrated on a movable mobile device; having the non-contact speedometer moving with the mobile device measure a measured speed; having a reference speedometer measure the speed of the non-contact speedometer moving with the mobile device as a reference speed; and generating a calibration signal for calibrating the measured speed of the non-contact speedometer based on the measured speed and the reference speed.

[0014] In the above-described method for calibrating a non-contact speedometer, an object to be measured by the non-contact speedometer may be arranged parallel to the direction of movement of the mobile device, and the non-contact speedometer may irradiate light onto the object to be measured and measure the speed based on the light reflected from the object to be measured.

[0015] In the above-described method for calibrating a non-contact speedometer, a reference speedometer may be disposed opposite the non-contact speedometer, and the reference speedometer may irradiate light onto the non-contact speedometer and measure the reference speed based on the light reflected from the non-contact speedometer.

[0016] In the above-described method for calibrating a non-contact speedometer, a reference speedometer may be disposed opposite the non-contact speedometer, the reference speedometer may irradiate the non-contact speedometer with light and measure the reference speed based on the light reflected from the non-contact speedometer, and the non-contact speedometer, the reference speedometer, and the object to be measured may be disposed so that the light reflected from the object to the non-contact speedometer and the light reflected from the non-contact speedometer to the reference speedometer form a right angle.

[0017] In the above-described method for calibrating a non-contact speedometer, the reference speedometer may be arranged in the direction of movement of the moving device or in the direction opposite to the direction of movement.

[0018] The method for calibrating a non-contact speedometer may further include transmitting a calibration signal to the non-contact speedometer.

[0019] In the above-described method for calibrating a non-contact speed meter, the calibration signal may be configured to bring the measured speed closer to the reference speed.

[0020] In the above-described method for calibrating a non-contact speed meter, a time stamp may be added to the measured speed. Also, a time stamp may be added to the reference speed. In generating the calibration signal, the measured speed and the reference speed transmitted at the same time may be compared based on the time stamp. [Effects of the Invention]

[0021] The present invention provides a novel system and method for calibrating a non-contact speed meter. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a schematic diagram showing a calibration system for a non-contact speed meter according to an embodiment. [Figure 2] FIG. 2 is a schematic diagram showing an optical velocimeter of the surface profile measuring apparatus according to the embodiment. [Figure 3] FIG. 3 is a schematic diagram showing an optical velocimeter of the surface profile measuring apparatus according to the embodiment. [Figure 4] FIG. 4 is a schematic diagram showing an optical velocimeter of the surface profile measuring instrument according to the embodiment. [Figure 5] FIG. 5 is a schematic graph showing the relationship between the reference speed and the measurement speed according to the embodiment. [Figure 6] FIG. 6 is a schematic graph showing the relationship between the reference speed and the measurement speed according to the embodiment. [Figure 7] FIG. 7 is a flowchart showing a method for calibrating a non-contact speed meter according to the embodiment. [Figure 8] FIG. 8 is a schematic diagram showing a calibration system for a non-contact speed meter according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, identical or similar parts are denoted by identical or similar reference numerals. However, the drawings are schematic. Therefore, specific dimensions and the like should be determined in light of the following description. Furthermore, it goes without saying that the dimensional relationships and ratios between the drawings may differ.

[0024] As shown in FIG. 1, the calibration system for a non-contact speedometer according to the embodiment includes a movable mobile device 20 on which a non-contact speedometer 10 to be calibrated is placed, a reference speedometer 30 that measures the speed of the non-contact speedometer 10 moving together with the mobile device 20 as a reference speed, and a calibration signal generation unit 301 that generates a calibration signal for calibrating the measured speed of the non-contact speedometer 10 based on the measured speed measured by the non-contact speedometer 10 moving together with the mobile device 20 and the reference speed.

[0025] The moving device 20 is capable of moving in one direction on the plane 21. In the present disclosure, the moving direction of the moving device 20 may be referred to as the x direction, and the direction perpendicular to the x direction may be referred to as the y direction. The moving device 20 may reverse its moving direction and move back and forth. The moving device 20 may have any shape on which the non-contact speed meter 10 can be placed. For example, the moving device 20 may have a stage on which the non-contact speed meter 10 can be placed.

[0026] The calibration system may further include a measurement object 40 for the non-contact speed meter 10. The measurement object 40 is arranged parallel to the movement direction of the moving device 20. The measurement object 40 has, for example, a plane parallel to the plane 21 along which the moving device 20 moves. The plane 21 may be part of a substrate 22 on which the non-contact speed meter 10 is arranged. The surface of the measurement object 40 may be covered with a reflecting object 41. The reflecting object 41 is made of a material with high light reflectivity, such as metal. The measurement object 40 is, for example, fixed and does not move.

[0027] The non-contact speedometer 10 may be an optical speedometer. When the non-contact speedometer 10 is an optical speedometer, the non-contact speedometer 10 irradiates the measurement object 40 with irradiation light and calculates the speed of the non-contact speedometer 10 relative to the measurement object 40 based on the light reflected from the measurement object 40.

[0028] The optical speedometer may be a laser Doppler speedometer. When the non-contact speedometer 10 is a laser Doppler speedometer, the non-contact speedometer 10 includes a light source 201 that emits a laser beam, as shown in FIG. 2. The laser beam passes through a collimating lens 202 and is split into two beams by a half mirror 203. One of the split laser beams is reflected by a mirror 204, and the two laser beams are incident on the measurement object 40 at an incident angle θ and interfere with each other. The scattered light reflected by the measurement object 40 is collected by a collecting lens 205 and received by a light-receiving element 206.

[0029] The relationship between the frequency F of the Doppler signal obtained from the light receiving element 206, the velocity V of the non-contact velocimeter 10 relative to the measurement object 40, the wavelength λ of the laser light, and the incident angle θ of the laser light is given by the following equation (1). F=(2V / λ)sinθ (1) The wavelength λ of the laser light and the angle of incidence θ of the laser light can be obtained in advance. The frequency F of the Doppler signal can be obtained by performing a Fourier transform on the time change of the light received by the light receiving element 206. Therefore, by obtaining the frequency F of the Doppler signal, the non-contact velocimeter 10 can calculate the velocity V of the non-contact velocimeter 10 relative to the measurement object 40.

[0030] The non-contact speedometer 10 may be a self-coupling speedometer. When the non-contact speedometer 10 is a self-coupling speedometer, the non-contact speedometer 10 includes a light source 211 that emits a laser beam, as shown in FIG. 3 . The laser beam is incident on the measurement object 40. The scattered light reflected by the measurement object 40 travels in the opposite direction along the same optical path as the irradiated light, and the returning light that re-enters the optical resonator in the light source 211 interferes with the laser beam generated in the optical resonator. This interference indicates that a self-coupling effect occurs in the optical resonator. The light-receiving element 212 detects an interference waveform generated by the self-coupling. Based on the period of the interference waveform, the non-contact speedometer 10 calculates the speed of the non-contact speedometer 10 relative to the measurement object 40.

[0031] The non-contact speedometer 10 may be a spatial filter speedometer. When the non-contact speedometer 10 is a spatial filter speedometer, the non-contact speedometer 10 includes a light source 221 that emits light, as shown in FIG. 4. The measurement object 40 is irradiated with the condensed light from an oblique direction so as to provide dark-field illumination for the light-receiving optical system of the non-contact speedometer 10. The light scattered by the measurement object 40 is condensed by a condenser lens 222, and an image of the measurement object 40 is formed on a grating 223 having a periodic transmittance distribution.

[0032] If the magnification of the light receiving optical system is M and the speed of the non-contact speedometer 10 relative to the measurement object 40 is V, the image on the grating 223 moves at a speed MV. Light transmitted through the grating 223 is received by the light receiving element 224. If the spacing of the grating 223 is p, the period F of the signal of the transmitted light received by the light receiving element 224 is given by the following equation (2). F=MV / p (2) Since the magnification M of the light receiving optical system and the spacing p of the grating 223 can be obtained in advance, the non-contact velocimeter 10 calculates the velocity V of the non-contact velocimeter 10 relative to the measurement object 40 by measuring the frequency F.

[0033] The method by which the reference speedometer 30 shown in FIG. 1 measures the reference speed of the non-contact speedometer 10 is not particularly limited. For example, the reference speedometer 30 measures the reference speed optically. For example, the reference speedometer 30 is disposed opposite the non-contact speedometer 10. The reference speedometer 30 may be disposed in the moving direction of the moving device 20 or in the opposite direction to the moving direction. The reference speedometer 30 is, for example, fixed and does not move. The reference speedometer 30 irradiates light onto the moving non-contact speedometer 10 and measures the moving speed of the non-contact speedometer 10 as the reference speed based on the reflected light from the non-contact speedometer 10. For example, the reference speedometer 30 measures the moving speed of the non-contact speedometer 10 based on the frequency of the irradiated light and the frequency of the reflected light. The non-contact speedometer 10 may be provided with a reflector 11 for reflecting the irradiated light emitted by the reference speedometer 30.

[0034] For example, the non-contact speedometer 10, the measurement object 40, and the reference speedometer 30 are arranged so that the light reflected from the measurement object 40 to the non-contact speedometer 10 and the light reflected from the non-contact speedometer 10 to the reference speedometer 30 are perpendicular to each other. For example, the direction of the light reflected from the measurement object 40 to the non-contact speedometer 10 is parallel to the y direction, and the light reflected from the non-contact speedometer 10 to the reference speedometer 30 is parallel to the x direction. This makes it possible to suppress the effects of rolling or yawing even if the measurement object 40 rolls or yawing.

[0035] The calibration system for a non-contact speedometer according to the embodiment may further include a control unit 303 for controlling at least one of the moving device 20, the non-contact speedometer 10, and the reference speedometer 30 via wired or wireless communication. The control unit 303 controls the movement of the moving device 20. The control unit 303 controls the start and stop of speed measurement by the non-contact speedometer 10. The control unit 303 controls the start and stop of speed measurement by the reference speedometer 30.

[0036] The calibration signal generation unit 301 generates a calibration signal to bring the measured speed closer to the reference speed. The non-contact speedometer 10 transmits the measured speed to the calibration signal generation unit 301 via a wired or wireless connection. The reference speedometer 30 transmits the reference speed to the calibration signal generation unit 301 via a wired or wireless connection. The calibration signal generation unit 301 receives the measured speed from the non-contact speedometer 10 and receives the reference speed from the reference speedometer 30.

[0037] The calibration signal generation unit 301 compares the measurement speed with the reference speed. For example, as shown in FIG. 5, if the measurement speed and the reference speed are the same, the calibration signal generation unit 301 does not generate a calibration signal. As shown in FIG. 6(a), if the measurement speed is faster than the reference speed, the calibration signal generation unit 301 generates a calibration signal to calibrate the measurement speed so that the measurement speed becomes equal to the reference speed. As shown in FIG. 6(b), if the measurement speed is slower than the reference speed, the calibration signal generation unit 301 generates a calibration signal to calibrate the measurement speed so that the measurement speed becomes equal to the reference speed.

[0038] The calibration signal is not particularly limited as long as it can calibrate the speed measured by the non-contact speedometer 10 shown in Fig. 1. For example, the calibration signal may include a coefficient or formula by which the measured speed calculated by the non-contact speedometer 10 is multiplied. Alternatively, the calibration signal may be a signal that calibrates the sensitivity of an optical system or the strength and frequency of an electrical signal of an electrical circuit used by the non-contact speedometer 10 to calculate the measured speed.

[0039] The calibration system for a non-contact speedometer according to the embodiment further includes a calibration signal transmission unit 302 for transmitting the calibration signal generated by the calibration signal generation unit 301 to the non-contact speedometer 10. The non-contact speedometer 10 is configured to receive the calibration signal and calculate a calibrated measured speed based on the calibration signal.

[0040] The calibration signal generating unit 301, the calibration signal transmitting unit 302, and the control unit 303 are included in a central processing unit (CPU) 300, for example.

[0041] Next, a method for calibrating the non-contact speed meter according to the embodiment will be described with reference to FIG.

[0042] In step S101, the non-contact speedometer 10 is placed on the moving device 20. In response to an instruction from the control unit 303, the reference speed measured by the reference speedometer 30 is reset to zero while the moving device 20 is stationary. Then, in step S102, in response to an instruction from the control unit 303, the reference speedometer 30 starts measuring the reference speed, and in step S103, in response to an instruction from the control unit 303, the non-contact speedometer 10 starts measuring the measured speed.

[0043] In step S104, in response to an instruction from the control unit 303, the mobile device 20 starts moving, and while the mobile device 20 is moving, the reference speedometer 30 continues measuring the reference speed, and the non-contact speedometer 10 continues measuring the measurement speed. The reference speedometer 30 transmits the measured reference speed to the calibration signal generation unit 301, and the non-contact speedometer 10 transmits the measured measurement speed to the calibration signal generation unit 301. Thereafter, in step S105, in response to an instruction from the control unit 303, the mobile device 20 stops moving, the reference speedometer 30 stops measuring the reference speed, and the non-contact speedometer 10 stops measuring the measurement speed.

[0044] In step S106, the calibration signal generation unit 301 generates a calibration signal based on the received reference speed and the measured speed. In step S107, the calibration signal transmission unit 302 transmits the calibration signal generated by the calibration signal generation unit 301 to the non-contact speedometer 10. The non-contact speedometer 10 is configured to receive the calibration signal and thereafter calculate a calibrated measured speed.

[0045] Although the present invention has been described above by way of the embodiments, the description and drawings forming part of this disclosure should not be understood as limiting the present invention. From this disclosure, various alternative embodiments, examples, and operating techniques will become apparent to those skilled in the art.

[0046] 8, the calibration system for a non-contact speedometer according to the embodiment may further include a time information providing device 400 that provides time stamps to the measured speed and the reference speed. The time information providing device 400 communicates with the non-contact speedometer 10 and the reference speedometer 30 via wired or wireless communication, and transmits time information to the non-contact speedometer 10 and the reference speedometer 30. The time information providing device 400 may be connected to an access point of the CPU 300 for wireless connection with the non-contact speedometer 10 and the reference speedometer 30.

[0047] When transmitting a measured speed, the non-contact speedometer 10 adds a timestamp to the measured speed based on time information. When transmitting a reference speed, the reference speedometer 30 adds a timestamp to the reference speed based on time information. The calibration signal generator 301 compares the measured speed and the reference speed transmitted at the same time based on the timestamp. This makes it possible to generate a highly accurate calibration signal.

[0048] Thus, it should be understood that the present invention encompasses various embodiments that are not described herein. [Explanation of symbols]

[0049] 10 non-contact speedometer, 11 reflective object, 20 moving device, 21 flat surface, 22 substrate, 30 reference speedometer, 40 measurement object, 41 reflective object, 201 light source, 202 collimating lens, 203 half mirror, 204 mirror, 205 condenser lens, 206 light receiving element, 211 light source, 212 light receiving element, 221 light source, 222 condenser lens, 223 grating, 224 light receiving element, 301 calibration signal generation unit, 302 calibration signal transmission unit, 303 control unit, 400 time information providing device

Claims

1. a moving device on which the non-contact speed meter to be calibrated is placed and which can be moved; a reference speedometer that measures the speed of the non-contact speedometer that moves together with the moving device as a reference speed; a calibration signal generating unit configured to generate a calibration signal for calibrating the measured speed of the non-contact speed meter based on the measured speed measured by the non-contact speed meter that moves together with the moving device and the reference speed; A non-contact speedometer calibration system comprising:

2. a measurement target of the non-contact speed meter that is parallel to the direction of movement of the moving device; the non-contact speed meter irradiates the measurement object with light and measures the measurement speed based on the light reflected from the measurement object; The calibration system for a non-contact speedometer according to claim 1 .

3. the reference speedometer is disposed opposite the non-contact speedometer; The reference speedometer irradiates the non-contact speedometer with light and measures the reference speed based on the light reflected from the non-contact speedometer.

3. The calibration system for a non-contact speedometer according to claim 1 or 2.

4. the reference speedometer is disposed opposite the non-contact speedometer; the reference speedometer irradiates the non-contact speedometer with light and measures the reference speed based on the light reflected from the non-contact speedometer; The non-contact speedometer, the reference speedometer, and the measurement object are arranged so that the light reflected from the measurement object to the non-contact speedometer and the light reflected from the non-contact speedometer to the reference speedometer form a right angle. The calibration system for a non-contact speedometer according to claim 2 .

5. 5. The calibration system for a non-contact speedometer according to claim 1, wherein the reference speedometer is arranged in a direction of movement of the moving device or in a direction opposite to the direction of movement of the moving device.

6. The calibration system for a non-contact speedometer according to claim 1 , further comprising a calibration signal transmitting unit for transmitting the calibration signal to the non-contact speedometer.

7. 7. The calibration system for a non-contact speed meter according to claim 1, wherein the calibration signal is configured to make the measured speed approach the reference speed.

8. Placing a non-contact speedometer to be calibrated on a movable moving device; the non-contact speed meter moving with the moving device measures a measured speed; a reference speedometer measuring the speed of the non-contact speedometer moving together with the moving device as a reference speed; generating a calibration signal for calibrating the measured speed of the non-contact speed meter based on the measured speed and the reference speed; How to calibrate a non-contact speedometer, including:

9. The method of calibrating a non-contact speedometer according to claim 8 , further comprising transmitting the calibration signal to the non-contact speedometer.

10. 10. The method for calibrating a non-contact speed meter according to claim 8, wherein the calibration signal is configured to make the measured speed approach the reference speed.

Images