TW200411184A - Laser velocimeter calibration apparatus and method thereof - Google Patents

Abstract

A laser velocimeter calibration apparatus and method thereof is for calibrating the velocity reading of a laser velocimeter on speed of objects, by utilizing a rotation member having one or a plurality of reflective faces and a rotation controller for controlling the rotation speed of the rotation member to simulate the length and speed of a moving object determined by parameters and rotation speed of the rotation member, the values of speed measured by the laser velocimeter is compared therewith such that the speed measured by the laser velocimeter can be calibrated.

Description

200411184

V. Description of the invention (1) [Technical field to which the invention belongs] The present invention is a calibration wear applied to a laser velocimeter by simulating the size of a traveling object and the degree of travel to achieve the purpose of freshness and correction. $ 射 ’则 速 仪 [Previous technology] Laser velocimeters can be roughly divided into Dupu,

Position, laser interference pattern or laser radar to measure the degree of moving objects. The working method of the Doppler velocimetry device is to emit a laser to a moving target. The light scattered by it and the original The light beam has a frequency difference, so the difference frequency signal of the two can be used to estimate the moving speed of the target. The laser interference pattern first uses the Doppler Burst signal generated by the laser to generate interference fringes when the object passes through the fringe ^ to estimate the moving speed of the object. In the prior art, the methods related to the calibration of laser speedometers are mostly directed to the calibration methods designed for these two types of laser speedometers', such as US application serial numbers 4176950, 4600301, 5598259, and 6088098. In addition, Light Detection and Ranging ’is a newer technology in traffic speed application compared to traditional radio wave radar speed measurement. In general, this type of laser light uses infrared rays, and its accuracy and reliability are far more than traditional radio wave radars. Among them, the Light Radar (Light Detection and Ranging 'LIDAR)' sends out infrared rays (infra-red) regularly. ) Laser to measure the return time of the beam 'Take any two of these times to calculate the speed. Since the laser beam emitted by the laser speed sensor is very narrow, a single speeding car can be picked out from the traffic flow, so it is more likely to be banned from overspeeding without the risk of being counter-detected.

200411184 V. Description of the Invention (2) Effect. Laser speed measurement uses laser emission to record time, and then record a frequency of 15 Η z so that it can be calculated. In addition to the previously mentioned function of measuring the length of the object by blocking the difference between several known animal bodies Speed, sturdy method [Content of the invention] The method of the present invention is to measure the speed of the rotating element and a controller to control the speed of the rotation through the calibration of the die-jet velocimeter. Principles and "The flight time of the radar electro-optic first records the time, the isochronous time, and then counts the operation (15 times per second). The traveling speed of the car is based on the principle of laser speed measurement. Therefore, the school of knowledge needs to have a detection method to achieve the "Doppler principle" of such waves, to calculate, that is, when the laser light to the laser light is reflected back by the object, the time difference is calculated, and the LIDAR device system, and The speed of light is 300,000 kilometers per second. Outside the instrument, another laser velocimeter is attached to the area to be measured, and when moving and moving objects leave each laser, This estimate was speedometer also has a positive method and system can not be applied to such technology, can provide a more simple, fast calibration of the laser gun. The purpose is to provide a laser velocimeter calibration device and the size and traveling speed of the object to be moved in order to achieve the purpose of lightning. The speed correction device includes a rotation controller with one or more reflecting surfaces to control the rotation speed of the rotating element. The rotating rotation element can simulate a specific length object at a specific speed. The speed and length of the object can be simulated with respect to the rotation. The parameters are determined by the rotation speed of the rotating element, and are compared with the measured speed value to achieve the correction of the laser.

200411184 V. Description of the invention (3) Speed measured by the speedometer. [Embodiment] Please refer to the first figure, which shows the implementation architecture diagram of the laser speedometer calibration device of the present invention. As shown in the first figure, the laser velocimeter calibration device of the present invention includes at least a rotating element 1 1. The rotating element 11 has one or more reflective surfaces or shielding surfaces, and is used to block a laser velocimeter. A laser beam emitted by the instrument; and a rotation controller 13 for controlling the rotation speed of the rotation element 11. Please continue to refer to the first figure. This preferred embodiment of the present invention is a calibration device and method for a speedometer that emits two laser beams. As shown in the first figure, the front surface of the rotating element 11 facing the laser velocimeter 12 has two masking surfaces, which can be divided into four regions. The first fan-shaped rotating regions 1 and Two fan-shaped rotating regions 3 and non-masked rotating regions 2 and 4. Among them, the first fan-shaped rotating region 1 and the second fan-shaped rotating region 3 are objects for simulating movement and can block the laser speedometer 1 2 The two laser beams 5 and 6 are emitted, and the first fan-shaped rotating area 1 and the second fan-shaped rotating area 3 both have a spread angle. According to the rotation direction of the rotating element 11, the first fan-shaped rotating region 1 is bounded by a leading edge 7 and a rear edge 8; on the other hand, the second fan-shaped rotating region 3 is also bounded by a leading edge 10 and a trailing edge 9. The two laser beams emitted by the laser velocimeter 12 are the laser beam 5 and the laser beam 6, respectively, and the parallel distance d between the laser beam 5 and the laser beam 6 is equal to the laser velocimeter 1 2 The distance between the two emitted lasers; when the laser velocimeter 12 is calibrated, both the laser beam 5 and the laser beam 6 fall on the rotating element 11 and the first fan-shaped rotating area of the mask surface 1 and the second fan-shaped rotation 111 m 1 ι _ ι 200411184 V. Description of the invention (4) Zone 3 will block the laser beams 5, 6 and the rotation zones 2, 4 will transmit the laser beams 5, 6. Among them, C is the center of the rotation axis of the rotating element 11 and α is the angle formed by the straight line connecting the position of the laser beam 6 at the position of the rotating element 11 and the center C of the rotation axis and the leading edge 10 of the second sector-shaped rotation region. Therefore, the parameters on the rotating element 11 include: the included angle α, the unfolding angle 第一 of the first fan-shaped rotating region 1 and the second fan-shaped rotating region 3, and the two laser beams 5 emitted by the laser velocimeter 12 And 6 fall on a distance d on the surface of the rotating element 11; and the angular velocity (ω) of the rotating element 11 is controlled and adjusted by the rotation controller 13. According to the correction method implemented by the present invention, the rotation controller 13 controls the rotation element 11 to rotate at a specific rotation speed (ω). When the leading edge 7 of the first fan-shaped rotating area 1 contacts the laser beam 5, it indicates that the front end of a simulated linear traveling object reaches the position of the first laser beam; and when the leading edge 10 of the second fan-shaped rotating area 3 contacts When the laser beam 6 is reached, it indicates that the front end of the simulated linear traveling object reaches the position of the second laser beam. In contrast, when the trailing edge 8 of the first sector rotation region 1 leaves the laser beam 5, it indicates the simulated straight line. The rear end of the traveling object leaves the position of the first laser beam; and when the trailing edge 9 of the second fan-shaped rotating region 3 leaves the laser beam 6, it indicates the position where the rear end of the simulated straight traveling object leaves the second laser beam. The speed of a simulated linear traveling object simulated by the laser velocimeter calibration method of the present invention is V. When the rotating element 11 is rotated at a rotation speed ω, it is considered that the simulated linear traveling object passes at a speed V = ω X d / α, and the The length L of the simulated straight traveling object is equal to d X / 5 / α. Since the parameters α, / 3, d of the rotating element 11 and the rotation speed ω of the rotating element 11 are known, the present invention corrects the speed of the laser velocimeter by simulating the speed V and length L of the object.

Page 9 200411184 V. Description of the invention (5) Numerical values. The results obtained by the speed V and the length L are further explained below. Please refer to the second figure, and please refer to FIG. 1 together, which is a schematic diagram showing the implementation of the first embodiment of the laser velocimeter calibration device of the present invention. As shown in the second figure, in the first embodiment of the present invention, two light detectors 14 and 15 can be placed behind the rotating element 11 to detect the light emitted by the laser speedometer 12 The laser beam 5 and the laser beam 6. When the rotating element 11 starts to rotate, the first fan-shaped rotating region 1 and the second fan-shaped rotating region 3 will block the laser beam 5 and the laser beam 6 and cannot pass through, so that the photodetectors 14 and 15 cannot receive the lightning. The laser beams 5 and 6 are rotated, and the rotating regions 2 and 4 do not block the laser beams 5 and 6, so that the photodetectors 14 and 15 can receive the laser beams 5 and 6. Please refer to the third diagram, and please refer to the second diagram, which shows the waveform of the output signal of the photodetector in the second diagram. As shown in the third figure, it represents the output signals of light detectors 14 and 15 as a function of time. The horizontal coordinates represent time, and the vertical coordinates represent the output signal amplitudes of the two detectors. , Time 11 and time t 3 respectively indicate the time when the two laser beams are interrupted by the first fan-shaped rotating region 1 and the second fan-shaped rotating region 3 respectively, and time t 2 and time t 4 respectively indicate the two lightning The time when the laser beams pass through the non-fan-shaped rotating regions 2 and 4 respectively; 5t represents the time when the laser beam 5 contacts the leading edge 7 of the first fan-shaped rotating region and the laser beam 6 contacts the leading edge 10 of the second fan-shaped rotating region. Time difference. Therefore, it can be seen from the third figure that the time required for one rotation of the rotating element 11 is t1 + t2 + t3 + t4, so the angular velocity ω is

2; r / (tl + t2 + t3 + t4), and the times tl and t3 are related to the expansion angles of the first sector rotation area 1 and the second sector rotation area 3, and because the expansion angles of these two areas are both / 3, so 11 2 t 3, so the expansion angle / 3 = 11 X ω = t 3 X

Μ m Page 10 200411184 V. Description of the invention (6) ω, α is equal to the speed multiplied by the time difference 5 t, that is, a = 5 t X ω. Its derivation formula is as follows: t = d / V, t ~ CK / ύϋ fd / V = OL / (λ) > ω · (5 t = a α / 5 t and two ω d / δ t = V, that is, V = 6Jxd / (2 β 2 11 · ω L / ω = 11 L = V · 11, that is, L = dx / 3 / a Therefore, it can be inferred from tl, t2, t3, t4, and can be inferred from ω, a, and no simulation Speed V and length L. Please refer to the fourth figure, which is a schematic diagram showing the implementation of the second embodiment of the laser velocimeter calibration device of the present invention. As shown in the fourth figure, in the second embodiment of the present invention, the rotation The front surface of the component 11 only uses a fan-shaped rotating area of a single mask surface to simulate a linear traveling object. The fan-shaped rotating area is used to block the laser beam emitted by the laser speedometer 12 and the fan-shaped rotating area has a Unfolding angle. According to the rotation direction of the rotating element 11, the fan-shaped rotating area defines a leading edge and a trailing edge; the two laser beams emitted by the laser speedometer 12 are the laser beam 5 and the laser, respectively. Beam 6, and the parallel distance d between the laser beam 5 and the laser beam 6; C is the center of the rotation axis of the rotating element 11; when the laser beam 5 falls on the fan-shaped rotation At the leading edge of the zone, the angle formed by the laser beam 6 falling on the position of the rotating element 11 and the line connected to the center C of the rotating axis and the leading edge of the fan-shaped rotating zone is α; the angular velocity (ω) of the rotating element 11 is obtained Adjusted by the rotation controller 1 3. According to the correction method implemented by the present invention, the rotation controller 13 controls the rotation

Page 11 200411184 V. Description of the invention (7) Element 11 rotates at a specific speed (ω). When the leading edge of the fan-shaped rotating area contacts the laser beam 5, it represents a position where the front end of a simulated linear traveling object reaches the first laser beam; when the leading edge of the fan-shaped rotating area contacts the laser beam 6, then Indicates that the front end of the simulated linear traveling object reaches the position of the second laser beam; and when the trailing edge of the fan-shaped rotating area contacts the laser beam 5, it indicates that the rear end of the simulated linear traveling object leaves the first laser beam. Position; and when the trailing edge of the fan-shaped rotating area contacts the laser beam 6, it indicates the position where the rear end of the simulated linear traveling object leaves the second laser beam. In this embodiment, the speed of the linearly traveling object simulated by the laser speedometer calibration method of the present invention is V. When the rotating element 11 is rotated at a rotation speed ω, the simulated linearly traveling object is regarded as having a velocity V = ω X d / α passes, and the length L of the simulated linearly traveling object is equal to d x 10,000 / α. Please refer to the fifth figure, and please refer to the fourth figure, which shows the waveform of the output signal of the photodetector in the fourth figure. As shown in the fourth figure, it can be known from the output signal of the photodetector 14 that its period (T) is T = t 2-t 0, and the photodetector 15 and the photodetector 14 are subjected to the sector The time difference of the occlusion in the rotation zone (5 t = tO'-tO, so t1 = t0 = tl '-tO' and t2-tl = t2'-tl '; and a = (5tx ω, β 2 11 · ω •' therefore The following formulas can be derived: a = ω (ΐΟ?-Ϊ́0) = ω St --- (1) β = ω (ΐΗΟ) ... ⑴ d = V (tO '-tO) = V 5 t… ⑴ L- V (tl-tO)-(4) Therefore, from formula (1), formula (2), formula (3), and formula (4), m can be obtained. Page 12 200411184 V. Description of invention (8) The speed (V) and length (L) of the measured object are ν = ωχ (ά / α); L = d X (/ 5 / α) 〇 After a detailed description of the preferred embodiment of the present invention, those skilled in the art will be familiar with it It can be clearly understood that various changes and modifications can be made without departing from the scope and spirit of the patent application described below, and the present invention is not limited to the implementation modes of the embodiments in the description.

Page 13 200411184 Brief description of the diagram The first diagram is the implementation architecture diagram of the laser speedometer calibration device of the present invention. The second figure is a schematic diagram of the first embodiment of the laser velocimeter calibration device of the present invention. The third figure is the waveform diagram of the output signal of the second detector. The fourth figure is a schematic diagram of the implementation of the second embodiment of the laser velocimeter calibration device of the present invention. The fifth figure is a waveform diagram of the output signal of the fourth photodetector. [Comparison explanation of main component symbols] 1 —First fan-shaped rotation area 3 --- Second fan-shaped rotation area 2, 4 --- Non-fan-shaped rotation area 5, 6 ----. Laser beam 7 --- First fan shape Leading edge of rotating area 8 --- Following edge of second fan-shaped rotating area 9 --- Following edge of first fan-shaped rotating area 10 --- Leading edge of second fan-shaped rotating area 11 --- Rotating element 12 Laser velocimeter 13- --Square walk controller 14 '15 --- Light detector d --t Parallel distance of light C --- 4 Vehicle center ω --- Angular velocity >-Length

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Claims (1)

200411184 VI. Application Patent Scope 1. A laser velocimeter calibration device for calibrating one or two laser velocimeters, comprising: a rotating element with one or more masking surfaces, the masking surfaces can block the The two laser beams emitted by the laser velocimeter; and a rotation controller to control the rotation speed of the rotating element; wherein the rotation of the rotating element can simulate the speed of a traveling object, which is determined by the foregoing rotation speed and the two laser beams. The distance and the angle between the position where the laser beam falls on the rotating element and the edge of the mask surface are determined. 2. The laser velocimeter calibration device according to item 1 of the patent application scope, wherein the aforementioned rotating element is a disc element. 3. For the laser velocimeter calibration device according to item 1 of the patent application scope, the shape of the aforementioned shielding surface is a fan shape. 4. For the laser velocimeter calibration device in the scope of the patent application, the expansion angle of the aforementioned sector is related to the length of the simulated object. 5. The laser speedometer calibration device according to item 4 of the scope of patent application, wherein the aforementioned length is determined by the aforementioned spreading angle, the distance of the two laser beams, and the position where the laser beam falls on the rotating element and the edge of the mask surface. The angle between them is determined. 6. A laser velocimeter calibration device for calibrating one or two laser velocimeters, including: a rotating element with one or more masking surfaces, which can block the laser velocimeter Two laser beams emitted; and a rotation controller to control the rotation speed of the aforementioned rotating element; Page 16 200411184 6. The scope of the patent application, where the rotation of the rotating element can simulate the speed of a traveling object, the speed is determined by the position where the two laser beams fall on the surface of the rotating element, so that the laser velocimeter The speed measurement value is corrected by the aforementioned speed. 7. —A laser velocimeter calibration method for calibrating one or two laser velocimeters, comprising: providing a rotating element, the rotating element having one or more masking surfaces, and the masking surfaces can block the The two laser beams emitted by the laser velocimeter; control the rotating element to rotate at a rotation speed; the rotation speed, the distance of the two laser beams, and the position of the laser beam on the rotating element and the edge of the mask surface The included angle determines a simulated speed value; and the simulated speed value is used to correct the speed value of the laser velocimeter. 8. If the laser speedometer calibration method of item 7 of the patent application scope includes: providing a fan-shaped mask surface, the fan-shaped spreading angle, the distance between the two laser beams, and the laser beam falling on the rotating element The included angle between the upper position and the edge of the mask surface determines a simulated length. Page 17