CN103727961A - Method for correcting dynamic error of electro-optic theodolite - Google Patents

Abstract

The invention discloses a method for correcting the dynamic error of an electro-optic theodolite, relating to the field of photoelectricity measurement and control and solving the problem in a dynamic measurement process of an existing electro-optic theodolite that the system has time delay error for an encoder sampling center and an infrared camera exposure center are out of sync. The method comprises steps of calibrating a detection rack; taking the average value of three obtained change face data as a truth value; delaying parameter design; setting external triggering synchronizing signal delayed TD of a camera, selecting the value of an encoder so as to align the exposure time center with a miss distance and a sampling time of the encoder; measuring the angle at dynamic state and accurately calculating and setting external triggering synchronizing delayed TD of the camera, then setting the servo control parameter and amplitude of oscillation of an infrared theodolite, and collecting the date of sinusoidal motion of the full field by the infrared theodolite; obtaining information about azimuth angle and angle of pitch; and respectively carrying out subtracting on the azimuth angle and the angle of pitch with the truth value obtained in step one, and taking the square root value so as to obtain the angle measurement accuracy to realize error correction.

Description

Electro-optic theodolite dynamic error modification method

Technical field

The invention belongs to photoelectric monitoring field, be specifically related to electro-optic theodolite dynamic error modification method, in electro-optic theodolite accuracy detection, can be used for improving the angle measurement accuracy of electro-optic theodolite.Meanwhile, in the testing experiment of outfield, can be used for improving the outer trajectory trajectory coordinates of target.

Background technology

In guided missile, Spacecraft Launch process of the test, the data of the reflection such as the trajectory of rocket and satellite orbit test situation, great majority are obtained by measurement by radio and optics exterior trajectory measurement equipment, the measuring accuracy of these exterior trajectory measurement equipments, indicates the observing and controlling level of the spacecraft testings such as China's guided missile, satellite.And precision is life and the home to return to of exterior trajectory measurement equipment, due to measurement data and development, sizing and the improvement of precision analysis to spacecrafts such as guided missile, satellites closely related, therefore domestic each relevant unit all attaches great importance to the precision evaluation work of exterior trajectory measurement equipment.And electro-optic theodolite is the major equipment of target range photoelectric measurement, photoelectric measurement equipment is mainly sterically defined by measurement of angle, the intersection measured target of finishing dealing with, and further calculates the outer trajectory supplemental characteristic of target.The size of angle error directly affects positioning precision, and therefore the research of the source on angle error, impact and detection method is one of important research content of electro-optic theodolite.

The precision calibration of electro-optic theodolite is divided into static testing angle precision and dynamic testing angle precision two parts content, and kinetic measurement angle measurement accuracy draws on static testing angle precision basis.Herein the reason that affects electro-optic theodolite dynamic measurement error is analyzed, and the error correcting method based on time unifying proposed, position angle and angle of pitch angle error root-mean-square value through dynamic measuring angle correction are brought up to 10.07 " with 8.56 " by 27.89 " with 17.67 " respectively, the method effectively raises dynamic measurement precision, and other photoelectric measurement equipment is had to reference value.

Summary of the invention

The object of the invention is for solving due in electro-optic theodolite kinetic measurement process, scrambler sampling center is asynchronous with infrared camera exposure center, and the system delay error causing, proposed a kind of by analyzing experiment parameter, the infrared camera external trigger method of signal lag time is set, solves the synchronous problem of exposure.

Electro-optic theodolite dynamic error modification method of the present invention, the method comprises the following steps:

Step 1, demarcation testing stand; Adopt high precision Lycra transit, measure the angle value of three parallel light tubes, the angle value of described parallel light tube is the change face data of demarcating three parallel light tubes, and using the mean value of three change face data that obtain as true value;

Step 2, delay parameter design; Set the external trigger synchronizing signal time delay TD of camera, select encoder values, according to formula: T/2+T _delay=1.25ms × i, T is the time, the value of i is 0～7, realizes the time shutter and aligns with the sampling instant three of miss distance, scrambler;

Step 3, dynamic testing angle precision calculate; According to the external trigger synchronizing signal time delay TD of the infrared camera of step 2 setting, then servocontrol parameter and the amplitude of oscillation of infrared transit be set, the data while using infrared transit to the sinusoidal motion of full visual field gather; Obtain the information of position angle and pitching;

Step 4, the position angle that step 3 is obtained and angle of pitch information are poor with the true value that step 1 obtains respectively, and the value of the root of making even, obtains angle measurement accuracy, realizes the correction to error.

Beneficial effect of the present invention: the present invention proposes the method for using dynamic delay that correction is set, the time of exposure, miss distance, three element alignment of scrambler are arrived to synchronization.Provided under different system parameter time delay correction time computing formula.Use this formula can calculate different integral time to camera time delay setting just, and encoder data system of selection.Method of the present invention, at large visual field infrared electro measurement and control area, is conducive to improve the dynamic testing angle precision of large visual field infrared electro transit.Adopt the method for internal system time delay correction, dynamic measurement precision to electro-optic theodolite is revised, position angle and angle of pitch angle error root-mean-square value through dynamic measuring angle correction are brought up to 10.07 " with 8.56 " by 27.89 " with 17.67 " respectively, the method effectively raises dynamic measurement precision, and other photoelectric measurement equipment is had to reference value.

Accompanying drawing explanation

Fig. 1 is the testing environment composition schematic diagram of electro-optic theodolite dynamic error modification method of the present invention;

Fig. 2 is the revised electro-optic theodolite sequential relationship of time delay schematic diagram in electro-optic theodolite dynamic error modification method of the present invention;

Fig. 3 is the electro-optic theodolite sequential relationship schematic diagram of not time delay correction;

Fig. 4 is the outfield control experiment result of electro-optic theodolite dynamic error modification method of the present invention;

Embodiment

One, demarcate testing stand; Testing stand is demarcated and is completed in indoor calibration workshop, dress school, works after transit need to being positioned over to detection platform, and calibration system comprises the systems such as stable platform, infrared electro transit, heavy caliber parallel light tube, testing stand, 0.5 ＂ Lycra transit.After detection platform adjustment is stable, use the 5# light pipe of 0.5 ＂ Lycra transit to 0 °, position angle, the 1# light pipe of 0 ° of the angle of pitch, 90 °, position angle, 0 ° of the angle of pitch, and the 6# light pipe of 90 °, position angle, 65 ° of the angles of pitch is demarcated; Nominal data comprises change face data three times, then using the mean value of three secondary data as true value.Meanwhile, use the change face data of three light pipes of demarcation of 0.5 ＂ Lycra transit, for computing system error, zero difference, sight poor, lateral axis difference.Systematic error is for true value correction.

Two, time delay corrected parameter calculates; The sequential principle of electro-optic theodolite is must be by the time of exposure, miss distance, three element alignment of scrambler to synchronization.The reason that problem analysis produces, when transit is with certain speed, during acceleration movement, when the time shutter of infrared camera is 1ms, our infrared camera need to be exposed center and 8 one of them center-aligned of group coding device, therefore we need to be by synchronously time delay 500 μ s backward of the external trigger of scrambler in theory, but in system design process, data transmission, sampling instant, and servo-controlled restriction, the external trigger synchronizing signal of scrambler can not be revised, what can revise is the external trigger signal of camera, therefore need the external trigger synchronizing signal of camera time delay 750 μ s backward, select the 1st group coding device value.Time delay arranges rear work schedule relation as shown in Figure 4.The formula of sequential alignment is as follows, and when be T the integral time of infrared camera (T is generally whole millisecond), needing the scrambler of selecting is i[0:7] group, delay time arranges Tdelay, and three need to meet formula (1) so.

T/2+T _delay＝1.25ms×i (1)

Three, gather measurement data; After time delay arranges, pair warp and weft instrument carries out sinusoidal motion by the running parameter of 5 ° of 20 °/s of speed and the amplitudes of oscillation centered by beacon light, the position angle recording and angle of pitch information when then calculating respectively transit and moving upward and move downward.Measurement result is as shown in table 1, table 2, and table 1 is scrambler and the miss distance information of each two field picture when transit moves upward after time delay correction, the scrambler of each two field picture and miss distance information when after time delay correction, transit moves downward;

Table 1

Table 2

Four, revised accuracy computation result; When dynamic accuracy is measured, the servocontrol parameter of transit is that speed is set to 20 °/s, and the amplitude of oscillation is set to respectively 5 °.When infrared camera was worked with the integral time of 1ms, time unite subsystem take second synchronizing signal as benchmark, frequency division produce the synchronous external trigger signal of 100Hz to infrared camera as time reference.Produce the synchronous triggering signal of 800Hz to scrambler, as the working time benchmark of the system of scrambler simultaneously.When transit is taken beacon light in sinusoidal motion mode, can be when moving downward and move upward, to beacon light imaging, when above each time not being adjusted, when moving upward, moving downward, produce the time, scrambler, miss distance, the synthetic angle information that in image, comprise respectively.The root-mean-square value of the position angle recording and angle of pitch static measurement error and mean value are as follows respectively:

δ _ΔA＝10.07″ $\stackrel{\‾}{\mathrm{\ΔA}}={41967.82}^{\′\′}$

δ _ΔE＝8.56″ $\stackrel{\‾}{\mathrm{\ΔE}}={-260.21}^{\′\′}$

By measurement data, we see, after the center moment and scrambler angular alignment of exposing synchronous through the data of time delay correction, systematic error can be eliminated, thereby improve the dynamic measurement precision of electro-optic theodolite.

Five, do not carry out the measurement result of time delay correction; Provide the measurement data result of calculation of not passing through time delay correction simultaneously, thereby can embody time delay correction effect.During without time delay correction, the servocontrol parameter of transit is that speed is set to 20 °/s, and the amplitude of oscillation is set to respectively 5 °.When infrared camera was worked with the integral time of 1ms, time unite subsystem take second synchronizing signal as benchmark, frequency division produce the synchronous external trigger signal of 100Hz to infrared camera as time reference.Produce the synchronous triggering signal of 800Hz to scrambler, as the working time benchmark of the system of scrambler simultaneously.When transit is taken beacon light in sinusoidal motion mode, can be when moving downward and move upward, respectively to beacon light imaging, when above each time not being adjusted, when moving upward, moving downward, produce time of comprising in image, scrambler, miss distance, synthetic angle information in Table 3, table 4, the scrambler that when table 3 moves upward for transit, each two field picture is corresponding and miss distance information, the scrambler that when table 4 moves downward for transit, each two field picture is corresponding and miss distance information.

Table 3

Table 4

When transit positive movement, encoder values adopts as the 0th group coding device in Fig. 1.The root-mean-square value of the position angle recording and angle of pitch static measurement error and mean value are as follows respectively:

δ _ΔA＝15.63″ $\stackrel{\‾}{\mathrm{\ΔE}}={-41995.73}^{\′\′}$

δ _ΔE＝15.45″ $\stackrel{\‾}{\mathrm{\ΔE}}={-253.61}^{\′\′}$

When transit positive movement, encoder values adopts the 0th group coding device in accompanying drawing 3 equally.The root-mean-square value of the position angle recording and angle of pitch static measurement error and mean value are as follows respectively:

δ _ΔA＝9.99″ $\stackrel{\‾}{\mathrm{\ΔA}}={41943.73}^{\′\′}$

δ _ΔE＝11.94″ $\stackrel{\‾}{\mathrm{\ΔE}}={-271.88}^{\′\′}$

If be that one group of data is calculated by above Data Integration, the root-mean-square value of the position angle recording and angle of pitch static measurement error and mean value are as follows respectively:

δ _ΔA＝27.89″ $\stackrel{\‾}{\mathrm{\ΔA}}={41971.09}^{\′\′}$

δ _ΔE＝17.67″ $\stackrel{\‾}{\mathrm{\ΔE}}={-264.63}^{\′\′}$

From the root-mean-square value of overall position angle and angle of pitch static measurement error and the root-mean-square value of positive movement and back motion, can see, there is larger systematic error in equipment, and the stochastic error of equipment is very little, according to theory of errors knowledge, we can analyze the systematic error of equipment, test, then eliminates.

By measurement data, we see, after the center moment and scrambler angular alignment of exposing synchronous through the data of time delay correction, systematic error can be eliminated, thereby improve the dynamic measurement precision of electro-optic theodolite.

In present embodiment, in outfield, adopt with high precision calibration facility and carry out comparing experiment, in experimentation, the infrared ballistic camera measuring system of electro-optic theodolite and high precision apparatus are measured target ballistic trajectory simultaneously, measure substation and use the dynamic measurement method through revising, using 1ms, infrared camera time delay the integral time of infrared camera is 750 μ s, selects the first group coding device value.Measure the azimuth of target that obtains of substation and the target angle of pitch after dynamic error correction, carry out after intersection processing, intersection calculation result and high precision calibration facility are carried out to comparing.Calculate respectively the angle error of directions X, Y-direction, Z direction under two cover measuring equipment earth coordinates.Outfield comparison result as shown in Figure 4.As can be seen from Figure 4, wherein under earth coordinates, directions X, Y-direction, Z direction angle error mean value are respectively 11.32 ", 10.05 ", 2.71 ".

Claims (2)

1. electro-optic theodolite dynamic error modification method, is characterized in that, the method comprises the following steps:

Step 1, demarcation testing stand; Adopt high precision Lycra transit, measure the angle value of three parallel light tubes, the angle value of described parallel light tube is the change face data of demarcating three parallel light tubes, and using the mean value of three change face data that obtain as true value;

Step 2, delay parameter design; Set the external trigger synchronizing signal time delay TD of camera, select encoder values, according to formula: T/2+T _delay=1.25ms × i, T is the time, the value of i is 0～7, realizes the time shutter and aligns with the sampling instant three of miss distance, scrambler;

Step 3, dynamic testing angle precision calculate; According to the external trigger synchronizing signal time delay TD of the infrared camera of step 2 setting, then servocontrol parameter and the amplitude of oscillation of infrared transit be set, the data while using infrared transit to the sinusoidal motion of full visual field gather; Obtain the information of position angle and pitching;

Step 4, the position angle that step 3 is obtained and angle of pitch information are poor with the true value that step 1 obtains respectively, and the value of the root of making even, obtains angle measurement accuracy, realizes the correction to error.

2. electro-optic theodolite dynamic error modification method according to claim 1, it is characterized in that, employing Lycra transit described in step 1 is the parallel light tube of 0 ° of 0 ° and the angle of pitch to position angle, and position angle is that the parallel light tube of the parallel light tube of 0 ° of 90 ° and the angle of pitch and 90 °, position angle, 65 ° of the angles of pitch is demarcated.

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