CN103206966A - Precision measurement error correction method for single-axis air bearing table - Google Patents

Abstract

The invention relates to the technical field of measurement, and particularly relates to a precision measurement error correction method for a single-axis air bearing table, which solves the problems of unstable precision, poor compensation effect and the like of the existing rotation angle measurement error correction method. The precision measurement error correction method for the single-axis air bearing table comprises the following steps: regulating balance of an air bearing table, and subtracting the reading alpha i (i=1, 2, -, 17) of a computer by a selected detection angle beta i (i=1, 2, -, 17) to obtain a result which is equal to the rotation angle error value yi (i=1, 2, -, 17) of the air bearing table; conducting linear interpolation correction according to a formula xi=i(i=1, 2, -, 17), respectively calculating 16 linear piecewise functions, and correcting a grating angle displayed by the computer; then measuring a new rotation error value zi (i=1, 2, -, 17), conducting harmonic correction according to the formula, calculating a harmonic correction function, correcting the grating angle displayed by the computer to obtain a final rotation angle error value si (i=1, 2, -, 17), determining whether the rotation error value is larger than the required precision, and conducting harmonic correction again if the rotation error value is larger than the required precision, otherwise, processing the final result. The air bearing table precision measurement error correction method provided by the invention has the advantages of simple structure, low cost and high angle measurement precision.

Description

A kind of single-axle air bearing table precision measurement error calibration method

Technical field

The present invention relates to a kind of single-axle air bearing table precision measurement error calibration method, relate to field of measuring technique.

Background technology

Single-axle air bearing table is the multi-functional full physical simulation platform of developing for modern attitude of satellite control, and its principle is to make this platform suspension in the air by spraying pressurized air, thereby total system has the little advantage of damping.We must know its angular velocity and angular acceleration, so the height of its outer corner measurement precision has directly influenced the physical simulation effect of satellite attitude control system when calculating disturbance torque.

Have the cost height for the outer corner measurement error calibration method in present domestic engineering reality and the existing document, the algorithm complexity is restricted in the high precision applications, does not take full advantage of existing fine measuring instrument; Perhaps too rely on existing exact instrument, only carried out simple correction, its model is too idealized, and the engineering practice effect is bad, the angle measurement accuracy instability, and compensation effect is relatively poor.

Summary of the invention

Problems such as there is the precision instability in the present invention in order to solve existing outer corner measurement error calibration method, and compensation effect is relatively poor, and then a kind of air floating table precision measurement error calibration method is provided.

The present invention solves the problems of the technologies described above the technical scheme of taking to be:

A kind of single-axle air bearing table precision measurement error calibration method, the specific implementation process of described method is:

Step 1: with the air floating table adjustment;

Step 2: with autocollimation light pipe and 17 grating angular readings α that the rib body examination gets _i(i=1,2 ..., 17); α _i(i=1,2 ..., 17) deduct and detect angle β _i(i=1,2 ..., 17), its result equals the angular errors value y of air floating table _i(i=1,2 ..., 17); That is: y _i=α _i-β _i

β ₀Be the initial value of choosing according to the detailed programs precision;

Step 3: according to formula

Get x _i=i (i=1,2 ... 17) obtain 16 linearity correction piecewise functions respectively, the grating angle that computing machine shows is proofreaied and correct; X represents any rotation angle value before air floating table is proofreaied and correct, and y represents the modified value of air floating table corner;

Step 4: repeating step two, the corrected value that utilizes step 3 to try to achieve is measured new angular errors value z _i(i=1,2 ..., 17); z _i=(α _i-β _i)+y;

Step 5: according to formula

Obtain the harmonic correction function, the grating angle that computing machine shows is proofreaied and correct;

A wherein _i(i=0,1 ..., 8), b _i(i=1,2 ..., 8) and be model parameter, ω=0.01095 is quadravalence grating harmonic constant;

Step 6: calculate the modified value y of consideration air floating table corner and the final angular errors value s of harmonic wave correction function _i(i=1,2 ..., 17); s _i=z _i+ z;

Step 7: judge final angular errors value s _i(i=1,2 ..., 17) whether greater than accuracy requirement, if, return step 2, otherwise execution in step eight;

Step 8 obtains net result, finishes single-axle air bearing table precision measurement error correction.

The invention has the beneficial effects as follows:

Air floating table precision measurement error calibration method of the present invention, simple in structure, cost is low, angle measurement accuracy is high.

It is as follows to detect table for the angle of departure positional precision:

I counts	Detect angle β i, get β=10 ° 5 ' 5 "	Grating angular readings α i	Angle error
				1	31°15′40.29″	31°15′40.84″	0.55″
2	52°26′15.59″	52°26′15.28″	-0.31″
				3	73°36′50.88″	73°36′50.82″	-0.06″
4	94°47′26.18″	94°47′26.27″	0.09″
				5	115°58′1.47″	115°58′1.16″	-0.31″
6	137°8′36.76″	137°8′37.35″	0.59″
				7	158°19′12.06″	158°19′12.72″	0.66″
8	179°29′47.35″	179°29′47.25″	-0.1″
				9	200°40′22.65″	200°40′22.93″	0.28″
10	221°55′57.94″	221°55′58.04″	0.1″
				11	243°1′33.24″	243°1′33.09″	-0.15″
12	264°12′8.53″	264°12′7.84″	-0.69″
				13	285°22′43.82″	285°22′45.05″	0.23″
14	306°33′19.12″	306°33′19.62″	0.5″

15	327°43′54.41″	327°43′54.19″	-0.22″
				16	348°54′29.71″	348°54′30.02″	0.31″
17	10°5′5″	10°5′5″	0″

Description of drawings

Fig. 1 is the outer corner measurement synoptic diagram (among the figure: 1-air supporting stage body, 2-rib body, 3-light pipe, 4-grating) among the present invention; Fig. 2 is angular errors correcting process block diagram.

Embodiment

The invention will be further described for example below in conjunction with accompanying drawing

Embodiment one: in conjunction with Fig. 1 and 2, the detailed process of the single-axle air bearing table precision measurement error calibration method of present embodiment is as follows:

The detection of angle error detects with autocollimation light pipe and 17 rib bodies.At first, 17 rib bodies are installed and are fixed at air floating table, adjust rib body and light pipe system, make light pipe aim at a workplace of rib body, rotation axis system (detects the angle near detecting selected detection angle successively then

The initial value of β for choosing according to the detailed programs precision.Adjusting the micro-adjusting mechanism on the axle, make the reading of light pipe as far as possible little at every turn, measure 17 points, is that benchmark rotates air floating table successively with the angle measuring system, reads the reading α of computing machine _i(i=1,2 ..., 17), try to achieve angular errors.

Step 1: with the air floating table adjustment;

Step 2: with autocollimation light pipe and 17 grating 4 angular readings α that rib body 2 records _i(i=1,2 ..., 17); α _i(i=1,2 ..., 17) deduct and detect angle β _i(i=1,2 ..., 17), its result equals the angular errors value y of air floating table _i(i=1,2 ..., 17); That is: y _i=α _i-β _i

β ₀Be the initial value of choosing according to the detailed programs precision;

Step 3: set up the linear calibration model of error

(the wherein error angle of y for measuring) gets x _i=i (i=1,2 ... 17) carry out linear interpolation and proofread and correct, derive the linear interpolation formula

According to formula Get x _i=i (i=1,2 ... 17) obtain 16 linearity correction piecewise functions respectively, the grating angle that computing machine shows is proofreaied and correct; X represents any rotation angle value before air floating table is proofreaied and correct, and y represents the modified value of air floating table corner;

Step 4: repeating step two, the corrected value that utilizes step 3 to try to achieve is measured new angular errors value z _i(i=1,2 ..., 17); z _i=(α _i-β _i)+y;

Step 5: set up error harmonic correction model $z=\underset{i=0}{\overset{8}{\mathrm{\Σ}}}(a_i\cos \left(\mathrm{i\ωx}\right)+\underset{i=1}{\overset{8}{\mathrm{\Σ}}}{b}_i\sin \left(\mathrm{i\ωx}\right),$ A wherein _i(i=0,1 ..., 8), b _i(i=1,2 ..., 8) and be model parameter, w=0.01095 is quadravalence grating harmonic constant;

Definition

(j, k=0,1 ... 17), find the solution following system of equations,

j＝1，2，…17

Wherein

Obtain a _i(i=0,1 ..., 8), b _i(i=1,2 ..., 8);

According to formula

Obtain the harmonic correction function, the grating angle that computing machine shows is proofreaied and correct;

A wherein _i(i=0,1 ..., 8), b _i(i=1,2 ..., 8) and be model parameter, ω=0.01095 is quadravalence grating harmonic constant;

Step 6: calculate the modified value y of consideration air floating table corner and the final angular errors value s of harmonic wave correction function _i(i=1,2 ..., 17); s _i=z _i+ z;

Step 7: judge final angular errors value s _i(i=1,2 ..., 17) whether greater than accuracy requirement, if, return step 2, otherwise execution in step eight;

Step 8 obtains net result, finishes single-axle air bearing table precision measurement error correction.

Claims (1)

1. single-axle air bearing table precision measurement error calibration method, it is characterized in that: the specific implementation process of described method is:

Step 1: with the air floating table adjustment;

Step 2: grating (4) the angular readings α that records with autocollimation light pipe and 17 rib bodies (2) _i(i=1,2 ..., 17); α _i(i=1,2 ..., 17) deduct and detect angle β _i(i=1,2 ..., 17), its result equals the angular errors value y of air floating table _i(i=1,2 ..., 17); That is: y _i=α _i-β _i

β ₀Be the initial value of choosing according to the detailed programs precision;

Step 3: according to formula

Get x _i=i (i=1,2 ... 17) obtain 16 linearity correction piecewise functions respectively, the grating angle that computing machine shows is proofreaied and correct; X represents any rotation angle value before air floating table is proofreaied and correct, and y represents the modified value of air floating table corner;

Step 4: repeating step two, the corrected value that utilizes step 3 to try to achieve is measured new angular errors value z _i(i=1,2 ..., 17); z _i=(α _i-β _i)+y;

Step 5: according to formula

Obtain the harmonic correction function, the grating angle that computing machine shows is proofreaied and correct;

A wherein _i(i=0,1 ..., 8), b _i(i=1,2 ..., 8) and be model parameter, ω=0.01095 is quadravalence grating harmonic constant;

Step 6: calculate the modified value y of consideration air floating table corner and the final angular errors value s of harmonic wave correction function _i(i=1,2 ..., 17); s _i=z _i+ z;

Step 7: judge final angular errors value s _i(i=1,2 ..., 17) whether greater than accuracy requirement, if, return step 2, otherwise execution in step eight;

Step 8 obtains net result, finishes single-axle air bearing table precision measurement error correction.

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