JP2006250834A - Calibration method for speed measuring instrument, and device therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To calibrate an overall precision of a speed measuring instrument by using only a gravitational acceleration. <P>SOLUTION: The speed measuring instrument B is arranged in an instrument calibration posture with a frame rotated by 90° to make a line segment connecting the first and second respective sensors K<SB>1</SB>, K<SB>2</SB>constituting the speed measuring instrument B laid along a vertical direction, and is fallen naturally using a longitudinally long specified speed slider S<SB>1</SB>, in a speed measuring posture of the speed measuring instrument B, a falling-down theoretical calculated time T<SB>1</SB>until the second detected part 36 is detected by the second sensor K<SB>2</SB>after the first detected part 35 is detected by the first sensor K<SB>1</SB>is calculated theoretically, the plurality of respective first to Nth specified speed sliders S<SB>1</SB>-S<SB>n</SB>different in the falling-down theoretical calculated times is prepared preliminarily, the first to Nth specified speed sliders S<SB>1</SB>-S<SB>n</SB>are fallen down naturally, and each measured time measured practically by the speed measuring instrument of a calibration object is compared with the each falling-down theoretical calculated time to calibrate the precision of the speed measuring instrument that is precision of the calibration object. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  In the present invention, a shielding plate provided on an object to be measured such as a test vehicle of a vehicle collision test apparatus passes between first and second sensors having a predetermined interval along the traveling direction of the object to be measured. The present invention relates to a method for verifying the measurement accuracy of a speed measuring apparatus that measures time and measures the speed of the object to be measured, and the apparatus.

For example, in the vehicle collision test apparatus, the measurement accuracy of the speed measurement device has a great influence on the determination of the test result, so that a certain level of accuracy is required from the viewpoint of the reliability of the measurement result. Conventionally, as shown in Patent Documents 1 and 2, the detection accuracy of the speed measuring device itself, that is, the arithmetic device itself is increased by increasing the detection accuracy of the detection pulse of the arithmetic device constituting the speed measuring device. It was from beginning to end.
JP-A-8-278321 Japanese Patent No. 2,933,954

  On the other hand, verification (confirmation) of the accuracy of the arithmetic device of the speed measuring device is performed by inputting a reference signal, and the accuracy of the arithmetic device itself can be confirmed, but the accuracy of the entire speed measuring device is Not only the accuracy, but also the accuracy of the interval between a set of sensors, the accuracy of detection response of each sensor (variation of detection response), the display accuracy of a display that displays detected data, and the like are affected. Accordingly, the overall accuracy of the speed measuring device cannot be verified (confirmed) only by detecting the accuracy of the arithmetic device by inputting the reference signal.

  An object of the present invention is to enable verification of the overall accuracy of the speed measuring device only by using gravitational acceleration.

  In order to solve the above-mentioned problems, the invention of claim 1 is characterized in that the first and second sensors are attached to a frame at a set distance along the horizontal direction and are provided on an object to be measured such as a test vehicle. A method for measuring the time required for the shielding plate to pass between the first and second sensors and verifying the measurement accuracy of a speed measuring device for measuring the speed of the object to be measured. In addition, the platform is rotated 90 ° so that the line connecting the second sensors is along the vertical direction, and the object to be measured travels at a specific speed in the speed measurement posture of the speed measurement device. In this case, a theoretical calculation time of the time required to pass between the first and second sensors is defined as a travel theoretical calculation time, and the sensor light is transmitted along the vertical direction through the vertically long slider body. Specific speed slider with through-holes The slider is naturally dropped at a falling start position where the lower end edge of the transmission hole is lower than the upper first sensor, and the first detected part which is the upper end edge of the transmission hole is detected by the first sensor. The theoretical calculation time of the fall until the second detected portion at the lower end of the slider body is detected by the second sensor is calculated, and the theoretical calculation time is equal to the travel theoretical calculation time. In this case, the slider having the drop theory calculation time is defined as a first specific speed slider, and a plurality of first to Nth specific speed sliders having different drop theory calculation times are prepared in advance, In the apparatus verification posture, each of the first to Nth specific speed sliders is naturally dropped as described above, and each measurement time actually measured by the speed measuring apparatus as the test object is It is characterized in that the measurement accuracy of the velocity measuring device, which is the test subject, is verified by comparison with each drop theory calculation time.

  In the verification method of the present invention, when the object to be measured travels at a specific speed in the speed measurement posture of the speed measurement device, the time calculated theoretically between the first and second sensors is calculated. It is defined as “travel theory calculation time”. In the “device verification posture” in which the frame of the speed measurement device is rotated 90 ° from the “speed measurement posture”, the first to Nth holes having holes in the vertical direction for transmitting the sensor light and having different verification target velocities are provided. By using the plurality of specific speed sliders, the sliders detected by the first and second sensors differ even if the specific speed slider naturally falls at a speed much lower than the speed to be verified. By setting the “falling theoretical calculation time”, which is the difference in detection time between the two detected parts, equal to the “running theoretical calculation time”, the measurement accuracy of the speed measuring device can be verified.

  In the specific speed slider, a vertically long slider body is formed with a transmission hole through which sensor light is transmitted along the vertical direction (vertical direction), and the second detected part formed at the lower end of the slider body is positioned above. By naturally dropping the slider at a position lower than the first sensor, the upper edge of the transmission hole, which is the first detected portion of the slider body, is detected by the upper first sensor, and then the slider body The dimension of each part of the slider is determined so that the time until the second detected part at the lower end is detected by the second sensor is equal to the “running theoretical calculation time”.

  Then, using a plurality of specific speed sliders having different verification target speeds, each of the first and second sliders detected by the first and second sensors provided on the “device verification posture” base By comparing the differences in the detection times of the detected parts with the "running theoretical calculation times" at multiple different speeds, the overall accuracy of the speed measurement device including sensors, calculators, and indicators can be integrated. Can be verified.

  Also, by correcting various errors such as dimensional errors due to thermal expansion of sliders due to the ambient temperature and errors due to differences in gravitational acceleration depending on the measurement area, the verification accuracy of the verification apparatus can be improved. Increased further. Furthermore, since it is portable, the verification device can be transported to an arbitrary place such as a place where the speed measurement device exists, and the speed measurement device can be verified using only gravitational acceleration. , It can be verified without the need to supply special utilities (power supply other than AC100V, water, air, etc.).

  The invention of claim 2 is a verification apparatus for carrying out the verification method of the speed measuring apparatus of claim 1, wherein the upper ends of a pair of support columns are separated by a fall start position determining plate at a predetermined interval in the horizontal direction. The first and second of the gantry are connected and arranged in a device verification posture in which the gantry is rotated 90 ° so that the line segment connecting the first and second sensors is along the vertical direction. It is detected by the first and second sensors after being dropped naturally with the upper end face in contact with the drop start position determining plate and a column-like gantry placed upright facing each sensor. And a plurality of specific speed sliders having different target speeds to be detected, the specific speed sliders transmitting sensor light along a longitudinal direction of a vertically long slider body. Through holes are formed, The upper edge of the hole is a first detected portion, and the second detected portion is provided at the lower end of the slider body. In the apparatus verification posture, one or more specific speed sliders are provided. The first and second detected parts measure time differences detected by the first and second sensors of the speed measuring device, and verify the measurement accuracy of the speed measuring device.

  According to the second aspect of the present invention, a frame having a simple configuration in which a drop start position determining plate is provided at the upper end, and the first and second sensors detected by the first and second sensors constituting the speed measuring device. By simply preparing a plurality of specific speed sliders having different detection target velocities provided with two detected parts, it is possible to verify the overall accuracy of the speed measuring device using only gravitational acceleration.

  The invention of claim 3 is characterized in that, in the invention of claim 2, the gantry is provided with an adjuster for both leveling and height adjustment.

  According to the third aspect of the present invention, the height of the gantry with respect to each of the first and second sensors provided in the speed measuring device of the “device verification posture” that is the test object can be adjusted, and the first test object of the slider can be adjusted. It is possible to accurately adjust the drop distance of the slider until the detection unit detects it by the first sensor, and the verification accuracy can be improved. At the same time, the drop start position determination plate at the upper end of the gantry can be set horizontally. Accuracy is increased.

  The invention of claim 4 is the invention of claim 2 or 3, wherein the gantry includes a sensor alignment jig for determining the height of the gantry with respect to each of the first and second sensors, and the gantry Is provided with a bracket for supporting the jig.

  According to the invention of claim 4, the sensor alignment jig is supported on the bracket provided on the frame of the verification device, and the first position relative to the reference position in the height direction provided on the sensor alignment jig is first. By irradiating the sensor light of at least one of the second sensor and the position of the gantry in the height direction with respect to each sensor, the accuracy of the test can be improved.

  According to a fifth aspect of the present invention, in the invention according to any one of the second to fourth aspects, a guide for preventing the slider from toppling is formed on an inner facing surface of each of the columns of the frame. Is characterized in that an impact absorber for absorbing the impact of the dropped slider is attached.

  According to the fifth aspect of the present invention, the slider can be prevented from overturning when it reaches the bottom of the gantry due to the presence of the guide, and the impact due to the collision of the slider is mitigated by the presence of the shock absorber. Damage or the like can be prevented, and as a result, the slider can be used repeatedly.

  According to the present invention, it is possible to collectively verify the overall accuracy including the accuracy of each of the arithmetic device, the sensor device, the display device, and the like constituting the speed measuring device only by using naturally occurring gravitational acceleration.

Hereinafter, the present invention will be described in more detail with reference to the best mode. FIG. 1 is a perspective view of the test apparatus A according to the present invention in use, FIG. 2 is a plan view, and FIG. 3 is a perspective view of the test apparatus A. As shown in FIGS. 1 and 2, a speed measuring device B used in a vehicle collision test apparatus includes a gantry 1 having both sides and a front surface that are open in use and having a U-shaped side shape. The first and second sensors K ₁ and K ₂ constituted by a pair of upper and lower are attached to a portion near the front opening 2 of the gantry 1, and the horizontal distance between the first and second sensors K ₁ and K ₂ . The speed of the passing vehicle is detected by measuring the time of the vehicle passing between (L ₀ ). Each of the first and second sensors K ₁ and K ₂ is a transmissive sensor and has light emitting portions K ₁₁ and K ₂₁ and light receiving portions K ₁₂ and K ₂₂ , respectively, and is integrated with the traveling vehicle. The attached shielding plate (not shown) passes between the light emitting parts K ₁₁ , K ₂₁ and the light receiving parts K ₁₂ , K ₂₂ , thereby shielding the sensor lights R ₁ , R ₂ from the upper side to the lower side. Then, the presence of the shielding plate is recognized. A caster 3 is attached to the gantry 1 and can be conveyed, and a control panel 4 is attached to the back side of the gantry 1.

When performing the verification of the speed measuring device B, as shown in FIG. 1, by rotating the speed measuring device B by 90 ° with respect to the use state (speed measurement state), first and second line segment connecting the sensor K _1, K ₂ are carried out arranged so as to be perpendicular.

The verification apparatus A according to the present invention is a column 10 that can be adjusted in height by a plurality of (four in the embodiment) adjusters 11 and that naturally falls from the drop start position at the upper end of the frame 10. , For a plurality of specific speeds for reading the difference in detection time between the first and second sensors K ₁ and K ₂ provided on the speed measuring device B in the “device verification posture” rotated 90 °. Sliders (hereinafter also simply referred to as “sliders”) S _{1 to} S ₃ are provided. The gantry 10 includes a base portion 13 disposed at a predetermined distance from the installation surface by four adjusters 11 via a mounting plate 12, and the sliders S _{1 to} S _{3 on} the top surface of the base portion 13. A pair of struts 14 erected opposite to each other with a gap wider than the width and the upper ends of the pair of struts 14 are integrally connected, and the sliders S _{1 to} S ₃ start falling. A fall start position determining plate 15 for determining the position is provided. As shown in FIG. 1, the sensor lights R ₁ and R ₂ emitted from the light emitting portions K ₁₁ and K _{21 of} the first and second sensors K ₁ and K ₂ are the speeds of the “apparatus verification posture”. The light beam is transmitted through the single column 14 of the verification device A installed at the setting position of the measurement device B, and is received by the light receiving portions K ₁₂ and K _22, and the presence of an object is detected by shielding the sensor lights R ₁ and R _2. Is confirmed.

The height of the gantry 10 of the verification device A is the vertical distance (L ₀ ) between the first and second sensors K ₁ and K ₂ of the speed measurement device B in the “device verification posture”, and the upper first sensor. It changes relatively with K ₁ as a main factor, such as the drop speed when the first detected portions 35 of the sliders S _{1 to} S ₃ are detected. Each of the sliders S _{1 to} S ₃ is opened in a state where its upper end surface is in contact with the lower surface of the drop start position determining plate 15, so that the slider drop space 16 between the pair of struts 14 facing each other is naturally formed. In the meantime, the first and second sensors K ₁ and K ₂ have a set time difference between the first and second detected portions 35 and 36 of the sliders S _{1 to} S ₃ , respectively. Is detected. The upper ends of the slider S ₁ to S _3, have gripping pieces 37 can be gripped is attached manually, the grip piece 37 is the fall start position determination plate during a drop starting position of each slider S ₁ to S ₃ In order to protrude upward from 15 and to be easily gripped, the width of the central portion in the longitudinal direction of the drop start position determining plate 15 (opposite direction of the pair of support columns 14) is formed narrower than both ends. Further, the sliders S _{1 to} S ₃ swing sideways at the falling start position or the sliders S _{1 to} S ₃ roll over on the opposing surfaces of the upper end and the lower end of the pair of support columns 14. A plurality of sets (three sets in the embodiment) of one-to-one set of guides 17 for prevention are attached. Further, an impact absorber 18 such as a thick rubber plate is attached to the upper surface of the base portion 13 to alleviate the impact of the sliders S _{1 to} S ₃ that collide and fall on the upper surface.

The verification method of the speed measuring device B according to the present invention is based on the sliders S _{1 to} S ₃ by the first and second sensors K ₁ and K ₂ that are provided one after the other on the speed measuring device B in the “device verification posture”. The actual detection time difference between the first and second detected portions 35 and 36 is calculated by referring to “the fall theory calculation time (T ₁ , T ₂ , The test is conducted by comparing with “T ₃ )”. Then, as shown in equation (4) described later, the “drop theory calculation time (T ₁ , T ₂ , T ₃ )” indicates that the first detected portion 35 of the sliders S _{1 to} S ₃ is the speed measuring device B. The drop speed when detected by the first sensor K ₁ (in other words, from the fall start position until the first detected portion 35 of the sliders S _{1 to} S ₃ is detected by the first sensor K _1. The distance (H ₀ ) where the sliders S _{1 to} S ₃ have dropped, the distance (L _{1 to} L ₃ ) between the first and second detected portions 35 and 36 of the sliders S _{1 to} S ₃ , This is a function of the distance (L ₀ ) between the first and second sensors K ₁ and K ₂ of the velocity measuring device B and the gravitational acceleration (g).

For this reason, the position of the verification device A in the height direction with respect to the first and / or second sensors K ₁ and K ₂ of the speed measurement device B placed on the pedestal 5 in the “device verification posture” (in other words, the first It is necessary to accurately determine the height position detected by the first and / or second sensors K ₁ and K ₂ . Accordingly, a pair of brackets 19 are attached to the side surfaces of the pair of support columns 14 of the verification apparatus A at different positions in the height direction, and the square bar-like height position detection jig 21 is attached to the pair of brackets 19. A detection line (not shown) provided horizontally at the center in the height direction of the jig 21 is detected by the first and / or second sensors K ₁ and K _{2 while} being horizontally supported. By adjusting the plurality of adjusters 11, the arrangement position of the verification device A in the height direction is determined. Further, the fall start position determining plate 15 is leveled by adjusting the plurality of adjusters 11.

Next, with reference to FIGS. 3 to 5 will be described slider S ₁ to S _3. The sliders S _{1 to} S ₃ have the same basic shape, and are substantially similar to the overall shape and transmit the sensor light R to the central portion of a rectangular slider body 31 that is long in the vertical direction in use. A rectangular transmission hole 32 is formed in the vertical direction, and concave portions 33 and 34 are respectively formed in the center portions in the width direction at the upper and lower end portions. The upper end edge of the rectangular transmission hole 32 constitutes a first detected portion 35 that is first detected by the upper first sensor K ₁ when the sliders S _{1 to} S ₃ naturally fall. The edge forming the bottom surface of the lower concave portion 34 constitutes a second detected portion 36 that is detected by the lower second sensor K ₂ after the first detected portion 35 is detected by the first sensor K ₁ . ing. As shown in FIGS. 1 and 3, each slider S _{1 to} S ₃ has a gripping piece 37 attached to the upper end portion thereof as described above, and the upper end surface of the slider body 31 is moved to the drop start position. The gripping piece 37 protrudes above the upper surface of the fall start position determining plate 15 in a state of being in contact with the back surface of the determination plate 15, and each slider S is held by gripping the protruding portion of the gripping piece 37. holds ₁ to S ₃ to drop the start position, the sliders S ₁ to S ₃ by the opening of the grip is adapted to freely fall from a drop starting position.

As shown in FIG. 5, the sliders S _{1 to} S ₃ are used for the verification of the specific speed, and therefore the vertical direction between the first and second detected parts 35 and 36. Only the distances (L ₁ , L ₂ , L ₃ ) are different. The sliders S ₁ , S ₂ , and S ₃ in the embodiment test the speeds of (80 km / h), (100 km / h), and (120 km / h), respectively, and the distance (L ₁ , L ₂ , L ₃ ), the relationship (L ₁ <L ₂ <L ₃ ) is established. In FIG. 5, δ ₁₂ and δ ₂₃ represent (L ₂ −L ₁ ) and (L ₃ −L ₂ ), respectively.

In FIG. 4, the slider S ₁ for testing the speed of 80 km / h is taken as an example, and the distance (L ₀ ) between the first and second sensors K ₁ and K ₂ of the speed measuring device B is 1 m (1 , 000 mm), and the distance (H ₀ ) where the slider S ₁ naturally falls from the drop start position determining plate 15 and the first detected portion 35 is detected by the first sensor K ₁ is 0. Assuming 6 m (600 mm), the following general formula and specific values are obtained. In FIG. 4, N ₁ and N ₂ indicate the height lines of the first and second sensors K ₁ and K ₂ , respectively, and the first detected portion at the drop start position of the slider S _1. 35 is located below the height line N ₁ of the first sensor K ₁ located above.

First, the slider at the drop starting position the slider S ₁ is naturally dropped from [4 (b)], when the first detection target portion 35 itself is detected by the first sensor K ₁ [4 (b)] If the falling speed of S ₁ is (V ₁ ) and the distance that the slider S ₁ has dropped by the time of the detection is (H ₀ ), equation (1) is established. However, (g) is the acceleration of gravity and was set to (9.8 m / s ² ) in the calculation of the following specific values.

Next, after the first detected portion 35 of the slider S ₁ is detected by the first sensor K ₁ , the second detected portion 36 is detected by the second sensor K ₂ [FIG. 4 (c)]. If the “falling theory calculation time” required for (T ₁ ) is (T ₁ ), Equation (2) is established.

Substituting (Equation 1) into (V ₁ ) in (Equation 2) establishes (Equation 3), and solving (Equation 3) for (T ₁ ) yields (Equation 4).

Here, in the actual speed measurement, the “travel theory calculation required to travel (1 m) which is the horizontal distance between the first and second sensors K ₁ and K ₂ at a speed of (80 km / h). “Time (T ₁₀ )” is (0.045 seconds). Also in the slider S ₁ that verifies the speed of (80 km / h), after the first detected portion 35 is detected by the first sensor K ₁ , the second detected portion 36 is detected by the second sensor K _2. If the “falling theoretical calculation time (T ₁ )” until this is equal to the “running theoretical calculation time (T ₁₀ )”, the actual falling speed of the slider S ₁ is the verification target speed (80 km / h). Even if it is much smaller than this, the measurement accuracy of the speed measuring device B can be verified.

Therefore, when (L ₁ ) is obtained by substituting each known value of (T ₁ ), (H ₀ ), and (L ₀ ) into (Equation 4), (L ₁ = 0.83 m) is obtained. In exactly the same manner, when L ₂ and L ₃ are obtained for the sliders S ₂ and S ₃ whose test target speeds are (100 km / h) and (120 km / h), respectively, (L ₂ = 0.87 m), ( L ₃ = 0.89 m).

Therefore, the intervals (L ₁ , L ₂ , L ₃ ) between the first and second detected parts 35 and 36 are different, and a plurality of sliders S _{1 to} S having specific different test target speeds. ₃ is subjected to the above-described verification test, and the “actual drop time” required when each slider S _{1 to} S ₃ naturally falls is measured, and the “running theoretical calculation time” of each slider S _{1 to} S ₃ is measured. By comparing with (T ₂₀ , T ₃₀ ) ”, the speed measuring device B is verified. The above-mentioned “actual fall time” is a time measured by the first and second sensors K ₁ and K ₂ , the arithmetic unit, the display, and the like constituting the speed measuring device B in cooperation. The total accuracy of the speed measuring device B can be verified by integrating the individual accuracy of each device constituting the speed measuring device B. Also, the verification test using the plurality of sliders S _{1 to} S ₃ having different verification target speeds causes the speed measurement device B to always generate an error with respect to the “drop theory time” at a constant rate at any speed. This is because the tolerance may be exceeded at a specific speed, but may exceed the tolerance at other specific speeds. Each of the sliders S ₂ and S ₃ “drop theory calculation time (T ₂ , T ₃ ) [equal to travel theory calculation time (T ₂₀ , T ₃₀ )]” is (0.036 seconds), (0. 03 seconds).

Since the sliders S _{1 to} S ₃ fall on the shock absorber 18 on the base portion 13, the impact of the fall is alleviated, and the sliders S _{1 to} S ₃ after dropping fall on the guide 17. Since it is supported, its rollover is prevented. Therefore, yet slider S ₁ to S ₃ to be used for the drop test, about the damage so minimal, and can be used repeatedly.

Further, the distance (L ₀ ) of the verification device A based on the ambient temperature, the distances (L _{1 to} L ₃ ) between the first and second detected portions 35 and 36 of the sliders S _{1 to} S ₃ , and the speed. The dimensional error due to thermal expansion of the distance (L ₀ ) between the first and second sensors K ₁ and K ₂ of the measuring device B, or the error due to the difference in gravitational acceleration depending on the measurement area, etc. By correcting, the “drop theory calculation time (T ₁ ′ to T ₃ ′)” of each slider S _{1 to} S ₃ taking into account the above errors can be theoretically calculated in advance, so the corrected “drop theory calculation time ( By performing the test based on “T ₁ ′ to T ₃ ′)”, the verification accuracy of the verification apparatus A is further increased.

In the above-described embodiment, three types of sliders S _{1 to} S ₃ having the verification target speeds of (80 km / h), (100 km / h), and (120 km / h) are given as an example. By subdividing different speeds with high measurement frequency of the measuring device B and further using various types of sliders, a highly accurate test can be performed.

  As described above, the verification apparatus A according to the present invention does not require any special utility (power supply other than AC 100V, water, air, etc.) and uses only the gravitational acceleration to provide a sensor, a computing unit, a display, etc. The total accuracy of the speed measuring device B including can be verified collectively. Moreover, since the verification apparatus A of the said embodiment is portable, it can carry out a verification by conveying to the arbitrary places (site) where the speed measurement apparatus B exists.

It is a perspective view of the use condition of the test | inspection apparatus A of this invention. It is also a plan view. It is a perspective view of the test | inspection apparatus A. FIG. (A), (b), (c), the drop starting position of the slider S ₁ respectively, the detection position of the first detection target portion 35, and an operation explanatory view illustrating the detection position of the second detection target portion 36. (A), (B), and (C) are front views of sliders S ₁ , S ₂ , and S ₃ , respectively.

Explanation of symbols

A: Testing device
B: Speed measuring device K ₁ : First sensor K ₂ : Second sensor L _{1 to} L ₃ : Distance between first and second detected parts of slider N ₁ , N ₂ : Sensor light height line R ₁ , R ₂ : Sensor light S _{1 to} S ₃ : Slider T _{1 to} T ₃ : Drop theory calculation time T _{10 to} T ₃₀ : Travel theory calculation time 10: Test device stand 11: Adjuster 14: Stand alone 15: Fall start position determining plate 18: shock absorber 31: slider body 32: transmission hole 35: first detected portion of slider 36: second detected portion of slider

Claims (5)

The first and second sensors are attached to the gantry at a set distance along the horizontal direction, and a shielding plate provided on the object to be measured such as a test vehicle is provided between the first and second sensors. Measuring the speed of the object to be measured and measuring the measurement accuracy of the speed measuring device for measuring the speed of the measured object,
Arranged in a device verification posture in which the gantry is rotated 90 ° so that the line connecting the first and second sensors is along the vertical direction;
When the measured object travels at a specific speed in the speed measurement posture of the speed measurement device, the theoretical calculation time is calculated as the time required to pass between the first and second sensors. And
Using a slider for specific speed in which a transmission hole for transmitting sensor light along the vertical direction is formed in a vertically long slider body, the slider has a lower end edge of the transmission hole at a drop start position lower than the upper first sensor. The first sensor detects the first detected part which is the upper edge of the transmission hole by the first sensor, and then the second sensor detects the second detected part at the lower end of the slider body. Calculate the theoretical calculation time until the
When the drop theory calculation time is equal to the travel theory calculation time, a slider having the drop theory calculation time is defined as a first specific speed slider, and a plurality of first to Nth different drop theory calculation times are provided. Prepare a slider for each specific speed in advance,
In the apparatus verification posture, each of the first to Nth specific speed sliders is naturally dropped as described above, and each measurement time actually measured by the speed measuring apparatus as the test object is measured. A speed measurement device verification method, wherein the measurement accuracy of a speed measurement device as a test object is verified by comparison with a theoretical calculation time. A verification device for carrying out the speed measurement device verification method of claim 1,
The upper ends of the pair of single columns are connected by a drop start position determining plate at a predetermined interval in the horizontal direction, and the gantry is moved so that the line segment connecting the first and second sensors is along the vertical direction. In a state where the device is placed in the rotated device verification posture, a column-like gantry that is erected and opposed to each of the first and second sensors of the gantry,
It is allowed to naturally fall in a state where the upper end surface is in contact with the fall start position determining plate, and the test target speed provided with the first and second detected portions detected by the first and second sensors. With different specific speed sliders,
In the specific speed slider, a vertically long slider body is formed with a transmission hole through which sensor light is transmitted along the vertical direction. The upper edge of the transmission hole serves as a first detected portion, and the lower end of the slider body. The second detected part is provided in the part,
In the apparatus verification posture, the first and second detected portions of the one or more specific speed sliders measure the time difference detected by the first and second sensors of the speed measuring apparatus, and the speed measuring apparatus A speed measuring device verification device characterized by verifying measurement accuracy. 3. The speed measuring device verification apparatus according to claim 2, wherein the gantry is provided with an adjuster for both leveling and height adjustment. The gantry includes a sensor alignment jig for determining the height of the gantry with respect to each of the first and second sensors, and the gantry is provided with a bracket for supporting the jig. 4. The speed measuring device verification device according to claim 2 or 3, characterized in that: A guide for preventing the slider from overturning is formed on the inner facing surface of each column of the gantry, and a shock absorber for absorbing the impact of the dropped slider is attached to the bottom of the gantry. The verification apparatus for a speed measuring device according to any one of claims 2 to 4.

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