CN101509819A - Uniaxial air bearing table balance adjustment method - Google Patents

Abstract

The invention aims to provide a single axle air bearing table balancing adjustment method with simple principle, low cost and convenient operation. The balancing adjustment method includes the following steps: step 1: the single axle air bearing table is adjusted to be not horizontal and a gradienter is used to measure an angle Alpha between the plane of the air bearing table and the local horizontal line; step 2: the air bearing table is caused to sway to-and-fro under the action of gravity and the swaying amplitude and cycle are recorded; step 3: the actual eccentricity L of the gravity and a revolving center of the single axle air bearing table are calculated according to the swaying cycle; step 4: a corresponding balance weight is arranged on a central line of recorded swaying angles at two sides of the air bearing table to adjust the balance; and step 5: the above steps are repeated until the eccentricity is zero or small enough to meet engineering requirements. The balancing adjustment method has simple principle, convenience, practicability, low cost and no electromagnetic interference to the single axle air bearing table.

Description

Uniaxial air bearing table balance adjustment method

(1) technical field

The present invention relates to measuring technique, is exactly uniaxial air bearing table balance adjustment method specifically.

(2) background technology

The air film that air floating table relies on pressurized air to form between air-bearing and bearing seat floats the simulation stage body, thereby realizes approximate friction free relative motion condition, with analog satellite in the outer space the very little mechanical environment of suffered disturbance torque.As satellite motion simulator, adopt single-axle air bearing table, can simulate a certain axial operation characteristic, to carry out full physical simulation by air floating table and have vital role, it is the indispensable instrument of demonstration and functional verification.Emulation facts have proved that not only checking has vital role to satellite attitude control system to utilize air floating table to carry out emulation, and can significantly improve the efficiency-cost ratio of satellite, reduces risk, shortens the R﹠D cycle.

For the attitude motion at the ground simulation satellite, the barycenter of single-axle air bearing table should be on the revolving shaft, otherwise will cause unbalanced moments, influences the quality of l-G simulation test.The trim mode of air floating table (comprising three-axis air-bearing table and single-axle air bearing table) mainly contains automatically and manual two kinds at present, by literature search, Chinese invention patent number: 200610009797.7, patent name is: externally loading centroid adjuster of air-floating rotating table, be installed in the barycenter of the bolt-nut mechanism adjustment turntable on the air floating table by adjustment, two kinds of working methods of manual and electric are arranged, and what this invention provided is a kind of adjusting gear, does not relate to concrete balance method.Li Yanbin, Baogang, Wang Zuwen, Lv Yandong etc. (see " Chinese inertial technology journal " at paper " Three Degree Of Freedom air floating table automatic-balancing system Dynamic Modeling ", 2005,13 the 5th phases of volume, page number 83-87) provided the three-axis air-bearing table automatic balancing arrangement in theoretically, do not provide concrete implementation method yet, be difficult to engineering and use.And said method all is at three-axis air-bearing table, is not suitable for single-axle air bearing table, yet there are no report at the active balance method data of single-axle air bearing table.

(3) summary of the invention

The object of the present invention is to provide the uniaxial air bearing table balance adjustment method that a kind of principle is simple, cost is low, easy to operate.

The object of the present invention is achieved like this: described uniaxial air bearing table balance adjustment method, and step is as follows:

Step 1: single-axle air bearing table is adjusted to out-of-level,, be designated as α with level measurement single-axle air bearing table plane and local horizontal angle;

Step 2: single-axle air bearing table is swung back and forth, the amplitude and the cycle of record swing under the effect of gravity;

Step 3: according to the actual eccentricity L that calculates the single-axle air bearing table center of gravity and the single-axle air bearing table centre of gyration hunting period;

Step 4: on the center line of the single-axle air bearing table both sides angle of oscillation that is write down, place corresponding counterweight counterweight and adjust balance;

Step 5: the step above repeating is zero or little till the engineering demands up to offset.

Uniaxial air bearing table balance adjustment method of the present invention, principle is simple, convenient and practical, expense is low, and single-axle air bearing table is not had electromagnetic interference (EMI).

(4) description of drawings

Fig. 1 is single-axle air bearing table pivot angle and single-axle air bearing table centre of gravity place synoptic diagram;

Fig. 2 is the calculating isoboles in single-axle air bearing table cycle;

Fig. 3 is a single-axle air bearing table counterweight counterweight placement location synoptic diagram;

Fig. 4 is placed on the position view of single-axle air bearing table face for level meter.

(5) embodiment

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

Embodiment 1, in conjunction with Fig. 1, Fig. 2, and uniaxial air bearing table balance adjustment method of the present invention, step is as follows:

Step 1: single-axle air bearing table is adjusted to out-of-level,, be designated as α with level measurement air floating table plane and local horizontal angle;

Step 2: single-axle air bearing table is swung back and forth, the amplitude and the cycle of record swing under the effect of gravity;

Step 3: according to the actual eccentricity L that calculates the single-axle air bearing table center of gravity and the single-axle air bearing table centre of gyration hunting period;

Step 4: on the center line of the single-axle air bearing table both sides angle of oscillation that is write down, place corresponding counterweight counterweight and adjust balance; Step 5: the step above repeating is zero or little till the engineering demands up to offset.

The single-axle air bearing table imbalance causes single-axle air bearing table to swing back and forth, the amplitude and the duration of oscillation of the both sides swing of record single-axle air bearing table obtain hunting period, calculate the actual eccentricity of the single-axle air bearing table center of gravity and the single-axle air bearing table centre of gyration according to this hunting period, can obtain the straight line at the line place of the single-axle air bearing table center of gravity and the single-axle air bearing table centre of gyration according to the position amplitude of swing, just can determine the position at single-axle air bearing table center of gravity place by offset that obtains and above-mentioned straight line, place the balance that corresponding counterweight counterweight is adjusted single-axle air bearing table at the middle separated time offside of single-axle air bearing table hunting range then.

Uniaxial air bearing table balance adjustment method of the present invention also comprises following feature:

1, before carrying out trim the single-axle air bearing table level is transferred to certain inclination angle, just artificial makes single-axle air bearing table out-of-level, but this out-of-level angle is as can be known or measurable.

2, described computing method are position and the cycles according to the single-axle air bearing table both sides swing that measures, and calculate the actual eccentricity of the single-axle air bearing table center of gravity and the single-axle air bearing table centre of gyration then.

3, described balance means are to place corresponding counterweight counterweight to adjust balance on the center line of single-axle air bearing table both sides angle of oscillation.

Embodiment 2, in conjunction with Fig. 1, Fig. 2, Fig. 3, Fig. 4, and uniaxial air bearing table balance adjustment method of the present invention, described computing method are as follows:

A certain angle at first tilts single-axle air bearing table, concrete operations are, pad pin or lower margin all are installed under the base of single-axle air bearing table, quantity is generally 3 (or more a plurality of), heightens or turn down the purpose (if any adjacent several pad pin of a plurality of just selections are heightened or turned down) that just can reach the single-axle air bearing table inclination with any 1 in 3 lower margins during adjustment.

With this tilt angle alpha of level measurement, concrete steps are then: (1) with level meter be placed on the single-axle air bearing table face on, as shown in Figure 4, level meter should be near the outward flange of single-axle air bearing table table top; (2) number of degrees of recording level instrument are designated as a ₁, single-axle air bearing table is rotated 90 °, the number of degrees of recording level instrument are designated as a ₂, again single-axle air bearing table being rotated 90 ° along same direction, the number of degrees of recording level instrument are designated as a ₃, again single-axle air bearing table being rotated 90 ° along same direction, the number of degrees of recording level instrument are designated as a ₄(3) according to formula $\mathrm{\α}=\sqrt{{\left(\frac{a_3-a_1}{2}\right)}^2+{\left(\frac{a_4-a_2}{2}\right)}^2}$ Obtain the inclination alpha of single-axle air bearing table.

Measure single-axle air bearing table hunting period and amplitude: single-axle air bearing table is tilted after a certain angle, the single-axle air bearing table imbalance must cause single-axle air bearing table to swing back and forth, the line of single-axle air bearing table center of gravity residing that and the single-axle air bearing table centre of gyration and the middle separated time that extended line is exactly this swing thereof.This owing to the uneven single-axle air bearing table that causes swings back and forth, the single-axle air bearing table consumed energy is finally stopped, position when this stops just single-axle air bearing table as the rest position of single pendulum, by the time single-axle air bearing table is static gets off afterwards with angle of its rotation, maximum pendulum angle scope and cycle that the record single-axle air bearing table swings back and forth, at first observe the swing situation of single-axle air bearing table during measurement, (just beyond the swing of single-axle air bearing table lower) installs indicating device beyond having a down dip then, such as a lightweight indicator stem is installed on single-axle air bearing table in advance, the extended line of indicator stem is by the centre of gyration (radial line of the single-axle air bearing table centre of gyration just) of single-axle air bearing table, the amplitude of fluctuation of single-axle air bearing table when swing record indicator stem and finishing the once time of swing, get the straight line that separated time wherein just can be determined single-axle air bearing table eccentric point and single-axle air bearing table centre of gyration line place according to the amplitude of the swing of single-axle air bearing table, again according to calculating the distance of this eccentric point hunting period apart from the single-axle air bearing table centre of gyration.Concrete computing method are: by the computing method of period of single pendulum, $T=2\mathrm{\π}\sqrt{\frac{L}{g\′}},$ Wherein T is single pendulum hunting period, and L is the length of pendulum, and g ' is the acceleration of gravity of equivalence.Concrete equivalent method is, g is single pendulum when not swinging when static (in an environment of living in), the tensile force f of cycloid (or equivalent cycloid) and the ratio g=F/m of swing ball quality m.For the swing of this single-axle air bearing table, suppose that single-axle air bearing table workplace and local horizontal angle are α, establishing hunting period is T, g is a local gravitational acceleration, L is for the vertical range of the centroidal distance single-axle air bearing table revolving shaft of pendulum (also being single-axle air bearing table), according to Fig. 2, by the period of single pendulum formula $T=2\mathrm{\π}\sqrt{\frac{L}{g\sin \mathrm{\α}}},$ Can calculate the distance L at the centroidal distance single-axle air bearing table center of pendulum (also being single-axle air bearing table).

Such as, with the level measurement inclination angle is 2.5 °, after determining the amplitude of single-axle air bearing table both sides swing, the middle separated time of making this amplitude angle can be determined the straight line at single-axle air bearing table eccentric point and single-axle air bearing table centre of gyration line place, suppose that be 5 seconds hunting period that records, then can calculate the distance at the centroidal distance single-axle air bearing table center of single-axle air bearing table according to formula

On this position, place suitable counterweight then.How concrete counterweight is selected, is placed referring to embodiment 4.

Embodiment 3, and in conjunction with Fig. 3, uniaxial air bearing table balance adjustment method of the present invention, described counterpoise are to select like this and placement:

When definite air floating table hunting period and amplitude, carry out Yi Bian have a down dip at it, one side carry out heavier in other words conj.or perhaps, one side counterweight just should be added in lighter going like this, i.e. the position of eccentric point and centre of gyration offside, as shown in Figure 3.It is the lightest to put quality when counterweight is placed in addition earlier, if do not meet the demands change into heavier, by that analogy, incremental.When the counterweight counterweight is placed, if installation test equipment on the set-point, at this moment need the operator to handle flexibly, if that is: counterweight is placed in permission on this testing equipment, just counterweight is placed on this equipment, according to inventor's operating experience for many years, the place that can place counterweight is always arranged on the general device; If do not allow to place counterweight, counterweight suitably can be placed on the place of departing from original position, this position redeterminates the hunting period and the amplitude of single-axle air bearing table then as far as possible near original position.

When adjusting counterweight, put a lighter counterweight earlier, add after the counterweight, repeat top operation again, obtain L ₂, then according to L ₂The increase and decrease counterweight:

If L ₂L, illustrating that the counterweight that adds is too heavy, balance has been put upside down direction, changes a lighter counterweight;

If 0＜L ₂＜L illustrates that the counterweight that adds is light, change one heavy a little, perhaps add up one lighter;

If L ₂=L illustrates that the counterweight that adds is too light, need add one heavier.

Concrete counterweight adds multiple, needs debugging at the scene, and the condition that the balance adjustment stops is: work as L ₂Just think that less than certain preset threshold balance meets the demands.Such as, according to testing requirements this threshold value is made as 0.1 meter, when adjusting balance if L ₂＜0.1 meter, just think that balance has met the demands.

Claims (1)

1. uniaxial air bearing table balance adjustment method, it is characterized in that: described balance adjustment method concrete steps are as follows:

Step 1: single-axle air bearing table is adjusted to out-of-level,, be designated as α with level measurement single-axle air bearing table plane and local horizontal angle;

Step 2: single-axle air bearing table is swung back and forth, the amplitude and the cycle of record swing under the effect of gravity;

Step 3: according to the actual eccentricity L that calculates the single-axle air bearing table center of gravity and the single-axle air bearing table centre of gyration hunting period;

Step 4: on the center line of the single-axle air bearing table both sides angle of oscillation that is write down, place corresponding counterweight counterweight and adjust balance;

Step 5: the step above repeating is zero or little till the engineering demands up to offset.

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