Dynamic radius positioning direct measurement method of rotary-platform-type precision centrifugal machine

Abstract

The invention discloses a dynamic radius positioning direct measurement method of a rotary-platform-type precision centrifugal machine. The method comprises the following steps of: measuring the radial run-out of the end face of a rotary platform, and recording the value as b0mm; recording the installation position of an accelerometer on the rotary platform as point A, and defining a point B and a point C on the rotary platform; intersecting a straight line BC with the end face of the rotary platform so as to form a point D and a point E; processing a groove in the vertical direction by respectively taking a vertical line of the point D and a vertical line of the point E as a center line; installing a fixed support and a capacitor-type position measuring sensor, wherein the capacitor-type position measuring sensor directly faces the end face of the rotary platform; rotating the rotary platform so as to obtain a collected result, and recording as a sequence Mi; analyzing the sequence Mi; repeating the test to complete the measurement of the dynamic radius of the rotary-platform-type precision centrifugal machine. According to the invention, the uncertain degree introduced by a to-be-measured installation block is eliminated without the use of the to-be-measured installation block; a single sensor is adopted for continuous measurement, the structure of a measurement system is simplified, the possibility of the measurement uncertain degree introduced by other links is reduced, and the measurement accuracy is improved obviously.

Description

technical field [0001] The invention relates to a method for measuring the dynamic radius of a turntable precision centrifuge, in particular to a high-precision method for directly measuring the dynamic radius of a turntable precision centrifuge without installing a measured mounting block. Background technique [0002] The precision centrifuge is one of the instruments used to calibrate and calibrate the accelerometer. It is realized by taking the centripetal acceleration as the input and testing the various performance parameters of the accelerometer. According to its working principle, the main factors affecting the calculation and measurement of centripetal acceleration include dynamic radius, dynamic misalignment angle, rotational speed, etc. [0003] The traditional method for measuring the dynamic radius of a rotary table precision centrifuge is to install capacitive, inductive, and laser position sensors on the rotary table or a fixed bracket, and then install the te...

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Problems solved by technology

[0005] 1. Install the tested mounting block on the turntable of the centrifuge to indirectly measure the change in the radius of the centrifuge. Due to different centrifugal accelerations, the fixed connection method, material, volume, and shape of the tested mounting block and the turntable are different. As a result, the position change of the measured mounting block is inconsistent with the position change of the turntable radius, which will introduce errors to the accurate measurement of the dynamic radius of the precision centrifuge;

[0006] 2. The precision centrifuge is used for the calibration and calibration of the accelerometer. The measurement position of the dynamic radius should be the position of the radial end face of the turntable where the accelerometer is installed on the turntable. The dynamic radius values ​​measured at other positions can only reflect the dynamics of the turntable of the precision centrifuge. The change trend of the radius cannot accurately measure the dynamic radius change of the radial end face position of the turntable corresponding to the installation of the accelerometer on the turntable. The position points of the dynamic radius measured by the traditional method are selected more, not only at the radial end face position of the turntable, so it will be Precision centrifuge calibration and calibration accelerometers introduce errors; and since the accelerometer installation location often has components different from other locations, such as mounting platforms and fixtures, the difference in dynamic radius changes caused by different masses should not be ignored;

[0007] 3. Selecting the trigger method for measurement will affect the working performance of the position sensor; using the position trigger method to measure the dynamic radius will keep the position sensor in an intermittent working state, which is not conducive to the stability and work of the sensor performance, and will affect the accuracy of the measurement;

[0008] 4. The method of using continuous acquisition to obtain the average value is to measure the dynamic radius change of the end face of the turntable of the precision centrifuge on the entire circumference, which reflects the change trend of the dynamic radius on the entire circumference, and cannot accurately reflect the designation of the end face of the turntable The position is the dynamic radius of the radial end face position of the turntable where the accelerometer is installed; on the one hand, the difference in the quality of the installation position will bring about different changes in the dynamic radius; Assembly errors will be introduced during the installation of the rotating shaft and the turntable, so the radii at different positions on the measurement turntable will be quite different, resulting in a large deviation in the measurement of the dynamic radius

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