CN101493317B - Anti-runout non-collaboration target laser corner and speed measurement method and apparatus - Google Patents

Abstract

The invention belongs to the technical field of optical precision measurement, relating to a non-cooperative target laser corner and speed measuring method and device for radial run-out prevention. The method uses two beams of laser to irradiate the diffuse rotary surface of a rotator and uses the characteristic that doppler shift effect of diffused reflection light irradiated along radial direction is insensitive to radial run-out of the rotator so that high-precision corner measurement is realized by interference detection technique. The measuring device in the invention comprises a laser and further comprises a photoelectric sensor, a convergent mirror, an optical fiber branching device, optical fibers, a frequency shifter, a first circuit of collimating mirror and a second circuit of collimating mirror; the invention uses the optical fibers to construct light paths, thereby reducing the volume of a measuring head; and simultaneously a plurality of measuring heads are installed on the rotary circumference of the rotator, thereby improving harmonic suppression characteristic of a single measuring head by using an error separation technology and eliminating the influence of radial run-out of the rotator on measuring results. The device has the characteristics of small volume, high real-time and good measuring stability.

Description

The noncooperative target laser corner of anti-diameter run-out and speed measurement method and apparatus

Technical field

The invention belongs to technical field of optical precision measurement, can carry out high precision corner, angular velocity, angular acceleration at rotor and measure, rotate control accurately and fast angle-data is provided for large-scale dynamo-electric corner system realizes high precision with big diameter run-out.

Technical background

The outer corner measurement sensor is widely used in Mechatronic Systems, and the corner value of especially large-scale dynamo-electric turntable shaft is obtained, the motion control of large multi-dimensional turntable etc. all be unable to do without the outer corner measurement sensor.But the outer corner measurement sensor of widespread use in the present dynamo-electric corner system, as grating angular encoder, induction synchro angle sensor, magnetic grid angular measurement sensor etc., owing to there are shortcomings such as the gap variable quantity is limited between the dynamic and static scale, measuring speed is low, can not satisfy the high precision of modern dynamo-electric platform corner, quick measurement requirement, and become the dynamo-electric corner of restriction system and further promote one of major influence factors of its performance, this situation seems particularly outstanding in large-scale dynamo-electric corner system.

For dynamo-electric corner system, rotor need carry out Fast Azimuth according to command request and rotate, be implemented in rotate or quiescent conditions under accurate rotational positioning.But the diameter of some large-scale multistage transmission rotors is about 2-3m, ton surplus in the of ten weighs, need the power of transmission big, back lash between gear train is also big, this just causes the rotating part of rotor and the gap between nonrotational part to change near the millimeter magnitude, and existing grating, magnetic grid, angle measuring systems such as inductosyn, because of its measuring principle is limit, be difficult to adapt to this moving, quiet scale gap changes situation greatly, thereby the outer corner measurement system of rotor has to be installed in the drive motor end, the corner data of rotor are also had to through multistage gear train transmission, by the angle measurement sensor-based system perception that is installed in drive end, and then resolve out by computing.

Because the volume of rotor is big, transfer motion power is big, transmission link is many, the transmission gap is big, the measurement chain length of corner data, thereby the transmission error of corner data is big, the data that its result measures the Electromechanical Control module can not really reflect the orientation corner information of rotor reality, make the outer corner measurement precision far below other module in the system, seriously reduce the control accuracy of Electromechanical Control module, restricted the overall performance of whole large-scale dynamo-electric corner system.

Angle measurement and velocity-measuring system are directly installed on the rotation gear ring position of rotor, obtain corner and rotating speed and be acknowledged as reasonable design scheme already, but its prerequisite are at first to develop corner and the tachometric survey sensor with anti-rotor diameter run-out.In fact, the angular measurement sensor technology of anti-rotor diameter run-out has become the technical bottleneck that the large-scale dynamo-electric corner of restriction system carries out the high precision Electromechanical Control.

The technological approaches that improves corner accuracy at present has two kinds of ways: the one, improve the kinematic train precision, and reduce the corner transmission error, but this can not tackle the problem at its root; The 2nd, what research can adapt to the rotor diameter run-out can directly be placed in locational new principle corner of rotor and speed sensing technology, fundamentally promotes the corner accuracy of dynamo-electric corner system, reduces the manufacturing cost of kinematic train.

At present, domestic raising has the approach of the outer corner measurement precision of big diameter run-out rotor, mainly by improving the kinematic train precision, reducing transmission link and realize, but this can not solve root problem, the precision of this type of outer corner measurement method can only reach 10 ' about, do not meet the design requirement of high precision corner of new generation system.

Based on this, the present invention proposes a kind of noncooperative target laser corner and speed measurement method and apparatus of anti-diameter run-out, and corner and the rotary speed precision of effectively breaking through existing rotor influence the technical bottleneck that is difficult to improve because of being subjected to multistage gear train precision.

Summary of the invention

First purpose of the present invention is in order to solve the problem that the big rotor of diameter run-out can't carry out the high precision outer corner measurement, the noncooperative target laser corner and the speed measurement method of anti-diameter run-out are proposed, this method is used the diffuse reflection rotary surface of two bundle laser radiation rotors, utilize doppler shift effect that outgoing radially diffuses to the insensitive characteristics of rotor diameter run-out, and then by interfering detection technique to realize the high precision outer corner measurement.

Second purpose of the present invention is noncooperative target laser corner and the speed measurement device that proposes anti-diameter run-out according to this measuring method.This device has the advantages that volume is little, real-time is high, measurement stability is good.

The objective of the invention is to be achieved through the following technical solutions.

The noncooperative target laser corner of anti-diameter run-out and speed measurement method, its measuring process is:

(a) measure the preceding light path of adjusting of beginning, making two bundle frequency differences is that the collimation laser of f shines the same diffuse reflection zone on the rotor rotary surface simultaneously, the part of two bundle collimation lasers diffuses along the radial direction outgoing of rotor, the diffuse light that this two bundle overlaps mutually interferes on the photoelectric sensor surface after focusing on through convergent mirror;

(b) in the measuring process, when rotor was static, the frequency difference of two bundle diffuse lights was f, the output signal frequency value of photodetector is f, when rotor rotates, moves along the tangential direction of rotary surface, make the diffuse light generation Doppler shift of two bundle collimation lasers, frequency shift value is a Δ _f, the frequency difference of two bundle diffuse lights is the f+2 Δ _f, the output signal frequency value of photodetector is the f+2 Δ _f

(c) calculate rotation data in the measuring process, the fluctuation number of times that at first needs recording light electric explorer output signal is n (t), recording light electric explorer output signal frequency is F (t), can calculate rotational angle θ (t), angular velocity omega (t), the angular acceleration ε (t) of rotor then according to formula (1) (2) (3):

$\mathrm{\θ}\left(t\right)=\frac{\mathrm{\λ}\·(n\left(t\right)-f\·t)}{2\sin (\mathrm{\α}/2)\·r}\left(\mathrm{rad}\right)---\left(1\right)$

$\mathrm{\ω}\left(t\right)=\frac{\mathrm{\λ}\·(F\left(t\right)-f)}{2\sin (\mathrm{\α}/2)\·r}(\mathrm{rad}/s)---\left(2\right)$

$\mathrm{\ϵ}\left(t\right)=\frac{\mathrm{d\ω}\left(t\right)}{\mathrm{dt}}(\mathrm{rad}/s^2)---\left(3\right)$

Wherein λ is a laser instrument output Wavelength of Laser, and r is the turning radius of rotor, and f is the frequency difference of the first via collimation laser and the second road collimation laser, and α is the angle of the first via collimation laser and the second road collimation laser.

This measuring method can also be installed a plurality of measuring heads on the circumference of rotor, adopt error separating technology, analyzes the data of a plurality of measuring heads, improves the harmonic wave rejection characteristic of single measuring head, eliminates the influence of rotating shaft diameter run-out to measurement result.

The noncooperative target laser corner of anti-diameter run-out and speed measurement device comprise laser instrument, also comprise, photoelectric sensor, convergent mirror, optical fiber splitter, optical fiber, frequency shifter, first via collimating mirror, the second road collimating mirror; Wherein laser process optical fiber enters the optical fiber splitter in the measuring head, and be divided into two-way: the one tunnel through outgoing first via collimation laser behind optical fiber and the first via collimating mirror, and another road laser is successively by outgoing the second road collimation laser behind optical fiber, frequency shifter, optical fiber and the second road collimating mirror; The same area on first via collimation laser and the second road collimation laser irradiation rotor circumference, the part of two bundle collimation lasers diffuses along the radial direction outgoing of rotor, the diffuse light that this two bundle overlaps mutually focuses on photodetector surfaces through convergent mirror, receive the output signal of photodetector at last by treatment circuit, and calculate the measurement of angle result.

Rotor is used for the conjunction measuring head, and to finish the rotary surface of measurement of angle be diffuse reflection surface.

This measurement mechanism can also comprise a plurality of measuring heads, is installed in around the circumference of rotor.

Beneficial effect

The present invention contrasts prior art and has following remarkable advantage:

1. the present invention utilizes doppler shift effect that outgoing radially diffuses to the insensitive characteristic of rotor diameter run-out, when rotor generation diameter run-out, two-way diffuses and can guarantee that interferometry do not interrupt, and diameter run-out is very little to outer corner measurement result's influence.

2. adopt two-way diffuse Doppler effect, interfere detection technique to merge mutually with the photosignal real-time processing technique, measure during the high-precision real of corner, angular velocity and the angular acceleration of realization diameter run-out rotor;

3. on rotor, cooperative targets such as grating chi, prism need be installed in the measuring process, can realize the outer corner measurement of noncooperative target by the diffuse surface of rotor;

4. apparatus of the present invention utilize optical fiber to make up light path, and the measuring head volume is little, antijamming capability is strong, stable and reliable for performance.

5. a plurality of measuring heads can be installed, utilize error separating technology to improve measuring accuracy, improve the harmonic wave rejection characteristic of single measuring head, further eliminate the influence of rotor diameter run-out measurement result.

Description of drawings

Fig. 1 is the principle schematic of measuring method of the present invention;

Fig. 2 is the diffuse reflection synoptic diagram of oblique incidence light;

Fig. 3 is the anti-diameter run-out principle schematic of measuring method of the present invention;

Fig. 4 is the interference region synoptic diagram on photoelectric sensor surface when diameter run-out takes place;

Fig. 5 is the structural representation of measuring head in apparatus of the present invention;

Fig. 6 is a measuring head distribution schematic diagram of the present invention;

Wherein: 1-rotor, 2-diffuse light, 3-photoelectric sensor, 4-convergent mirror, 5-first via collimation laser, 6-the second road collimation laser, 7-diameter run-out, 8-laser instrument, 9-optical fiber, 10-optical fiber splitter, 11-optical fiber, 12-optical fiber, 13-frequency shifter, 14-optical fiber, 15-first via collimating mirror, 16-the second road collimating mirror, 17-measuring head, 18-treatment circuit, 19-measuring head, 20-measuring head, 21-measuring head, 22-measuring head.

Embodiment

The invention will be further described below in conjunction with drawings and Examples.Embodiment carries out outer corner measurement at the revolving shaft with diameter run-out, and the radius of revolving shaft is 1.5m.

Basic thought of the present invention is to adopt two-way to diffuse to take place the interference signal behind the Doppler shift to realize accurate outer corner measurement, utilize doppler shift effect that outgoing radially diffuses to the insensitive characteristic of rotor diameter run-out, reduce the influence of diameter run-out angle measurement.The present invention uses optical fiber to make up light path, reduced the volume of measuring head, and a plurality of measuring heads are installed on the revolution circumference of rotor simultaneously, utilize error separating technology to improve the harmonic wave rejection characteristic of single measuring head, and eliminate the influence of rotor diameter run-out measurement result.

Embodiment

As shown in Figure 1, a kind of angle-measuring method of anti-rotor diameter run-out, its measuring process is:

At first, begin to adjust light path, the laser coupled of wavelength X=632nm laser instrument 8 is entered optical fiber 9, form two-way through optical fiber splitter 10 backs and measure light path, one the tunnel through optical fiber 11 and first via collimating mirror 15 back outgoing first via collimation lasers 5, and another road laser is successively by optical fiber 12,20Mhz frequency shifter 13, optical fiber 14 and the second road collimating mirror, 16 back outgoing, the second road collimation laser 6; Diffuse reflection surface on two-way collimation laser irradiation rotor 1 circumference, wherein the frequency difference of the first via collimation laser 5 and the second road collimation laser 6 is that 20Mhz, angle are 60 °.As shown in Figure 2, in the diffuse light of two-way collimation laser, some diffuse light 2 that overlaps mutually is along the radial direction outgoing of rotor.Then diffuse light 2 focuses on photodetector 3 surfaces through convergent mirror 4, and interferes, and after photodetector 3 is realized opto-electronic conversion, sends signal to treatment circuit 18, calculates the angle result by treatment circuit 18.

In the measuring process, when rotor 1 clockwise rotated, diffusing of first via collimation laser 5 produced Doppler's blue shift, the generation Doppler redshift that diffuses of the second road collimation laser 6, and the frequency difference that two bundles diffuse changes.

In the measuring process, by the burst of treatment circuit 18 storage photodetectors 3 outputs, and the fluctuation frequency n (t) of recording light electric explorer 3 output signals, recording light electric explorer 3 output signal frequency F (t);

Then, according to formula (1) (2) (3), treatment circuit 18 can calculate rotational angle θ (t), angular velocity omega (t), the angular acceleration ε (t) of rotor 1 in real time by computing circuit:

$\mathrm{\θ}\left(t\right)=\frac{\mathrm{\λ}\·(n\left(t\right)-f\·t)}{2\sin (\mathrm{\α}/2)\·r}\left(\mathrm{rad}\right)---\left(1\right)$

$\mathrm{\ω}\left(t\right)=\frac{\mathrm{\λ}\·(F\left(t\right)-f)}{2\sin (\mathrm{\α}/2)\·r}(\mathrm{rad}/s)---\left(2\right)$

$\mathrm{\ϵ}\left(t\right)=\frac{\mathrm{d\ω}\left(t\right)}{\mathrm{dt}}(\mathrm{rad}/s^2)---\left(3\right)$

Wherein, laser wavelength lambda=632 * 10 ^-9M, turning radius r=1.5m, frequency difference f=20 * 10 ⁶Hz, angle α=60 °.

As shown in Figure 3, in the measuring process when rotor generation diameter run-out 7, the first via collimation laser 5 of oblique incidence and the second road collimation laser, 6 irradiation areas still have lap, and radially outgoing of diffuse light is still arranged, and focus on the back on photodetector 3 surfaces through convergent mirror 4.As shown in Figure 4, owing to be subjected to the influence of diameter run-out, the focused light spot of two bundle diffuse lights on photodetector 3 surfaces do not overlap fully, but the interference that the zone of overlapping produces can have been satisfied the requirement of outer corner measurement.

As shown in Figure 5, a kind of angle-measuring equipment of anti-rotor diameter run-out wherein comprises in the measuring head 17: photoelectric sensor 3, convergent mirror 4, optical fiber splitter 10, optical fiber 11, optical fiber 12, frequency shifter 13, optical fiber 14, first via collimating mirror 15, the second road collimating mirror 16; Wherein the laser of 632nm process optical fiber 9 enters the optical fiber splitter 10 in the measuring head 17, and be divided into two-way: the one tunnel through optical fiber 11 and first via collimating mirror 15 back outgoing first via collimation lasers 5, and another road laser is successively by optical fiber c12,20Mhz frequency shifter 13, optical fiber 14 and the second road collimating mirror, 16 back outgoing, the second road collimation laser 6; The diffuse reflection surface of two-way collimation laser irradiation rotor 1 circumference, wherein the part diffuse light overlaps mutually, and along the radial direction outgoing of rotor 1, then focus on photodetector 3 surfaces, calculate the measurement of angle result by treatment circuit 18 according to the output signal of photodetector 3 at last through convergent mirror 4.

The angle-measuring equipment of present embodiment is installed the four measuring head on the circumference of rotor 1, the interval is 90 ° between per two measuring heads.By handling the data of four measuring head, the use error partition method is improved the harmonic wave rejection characteristic of measuring head, eliminates the influence of rotor diameter run-out to the angle measurement result.

This embodiment has realized having the high precision outer corner measurement of the rotor of diameter run-out by a series of measure, realized the outer corner measurement method and apparatus of anti-rotor diameter run-out, compare with conventional outer corner measurement method, has anti-diameter run-out interference performance, the measuring head volume is little, real-time good, and measuring accuracy can reach 2～4 " about.

Below in conjunction with the accompanying drawings the specific embodiment of the present invention is described; but these explanations can not be understood that to have limited scope of the present invention; protection scope of the present invention is limited by the claims of enclosing, and any change on claim of the present invention basis all is protection scope of the present invention.

Claims (5)

1. the noncooperative target laser corner of anti-diameter run-out and speed measurement method is characterized in that:

(a) measure the preceding light path of adjusting of beginning, making the two-way frequency difference is that the collimation laser of f shines the same diffuse reflection zone on the rotor rotary surface simultaneously, the radial direction outgoing of the mutual diffuse light that overlaps of two bundles along rotor arranged in the diffuse light of two-way collimation laser, wherein the radial direction of rotor is perpendicular to the rotary surface of rotor, the diffuse light that this two bundle overlaps mutually interferes on the photoelectric sensor surface after focusing on through convergent mirror;

(b) in the measuring process, when rotor is static, the frequency difference of two bundle diffuse lights is f, the output signal frequency value of photodetector is f, when rotor rotates, and the rotary surface of direction motion tangentially, make the diffuse light generation Doppler shift of two-way collimation laser, frequency shift value is Δ f, and the frequency difference of the diffuse light that described two bundles overlap mutually is f+2 Δ f, and the output signal frequency value of photodetector is f+2 Δ f;

(c) calculate rotation data in the measuring process, the fluctuation number of times that at first needs recording light electric explorer output signal is n (t), recording light electric explorer output signal frequency is F (t), can calculate rotational angle θ (t), angular velocity omega (t), the angular acceleration ε (t) of rotor then according to formula (1) (2) (3):

$\mathrm{\θ}\left(t\right)=\frac{\mathrm{\λ}\·(n\left(t\right)-f\·t)}{2\sin (\mathrm{\α}/2)\·r}\left(\mathrm{rad}\right)---\left(1\right)$

$\mathrm{\ω}\left(t\right)=\frac{\mathrm{\λ}\·(F\left(t\right)-f)}{2\sin (\mathrm{\α}/2)\·r}(\mathrm{rad}/s)---\left(2\right)$

$\mathrm{\ϵ}\left(t\right)=\frac{\mathrm{d\ω}\left(t\right)}{\mathrm{dt}}(\mathrm{rad}/s^2)---\left(3\right)$

Wherein λ is a laser instrument output Wavelength of Laser, and r is the turning radius of rotor, and f is the frequency difference of the first via collimation laser and the second road collimation laser, and α is the angle of the first via collimation laser and the second road collimation laser.

2. according to the noncooperative target laser corner and the speed measurement method of right 1 described anti-diameter run-out, it is characterized in that: a plurality of measuring heads of installing along the rotary surface of rotor, adopt error separating technology, analyze the data of a plurality of measuring heads, improve the harmonic wave rejection characteristic of single measuring head, eliminate the influence of rotating shaft diameter run-out measurement result.

3. the noncooperative target laser corner of anti-diameter run-out and speed measurement device, comprise laser instrument, it is characterized in that: also comprise photoelectric sensor, convergent mirror, optical fiber splitter, first optical fiber, second optical fiber, the 3rd optical fiber, the 4th optical fiber, frequency shifter, first via collimating mirror and the second road collimating mirror; Wherein laser enters optical fiber splitter in the measuring head through first optical fiber, and be divided into two-way: the one tunnel through outgoing first via collimation laser behind second optical fiber and the first via collimating mirror, and another road laser is successively by outgoing the second road collimation laser behind the 3rd optical fiber, frequency shifter, the 4th optical fiber and the second road collimating mirror; The same area on first via collimation laser and the second road collimation laser irradiation rotor rotary surface, the radial direction outgoing of the mutual diffuse light that overlaps of two bundles along rotor arranged in the diffuse light of two-way collimation laser, wherein the radial direction of rotor is perpendicular to the rotary surface of rotor, the diffuse light that this two bundle overlaps mutually focuses on the photoelectric sensor surface through convergent mirror, receive the output signal of photodetector at last by treatment circuit, and calculate the measurement of angle result.

4. according to the noncooperative target laser corner and the speed measurement device of right 3 described anti-diameter run-outs, it is characterized in that: rotor is used for the conjunction measuring head, and to finish the rotary surface of measurement of angle be diffuse reflection surface.

5. according to the noncooperative target laser corner and the speed measurement device of right 3 described anti-diameter run-outs, it is characterized in that: also comprise other a plurality of measuring heads, be installed in around the rotor rotary surface.

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