Measurement Method And Error Analysis Of Gyro Accelerometer Tested On Precision Linear Vibration Table

Precision linear vibration table is an important inertial navigation test equipment which can simulate high acceleration environment, provide sufficient input specific forces for the tested inertial instrument—— Gyro Accelerometer, provide sufficient excitation for the high-order error model coefficients of Gyro Accelerometer, provide test condition for calibrating error model coefficients of Gyro Accelerometer accurately,and achieve the aim of improving the precision of inertial navigation system finally.Therefore, the design of appropriate test methods and the analysis of error factors which have an impact on the test result are of great practical significance.By choosing appropriate test equipments in this article and using appropriate test method, the precision linear vibration table is measured, then the test results meet the requirements for the specifications. Considering the various errors of linear vibration,using homogeneous transformation method as a tool, by establishing relevant coordinate systems, homogeneous transformation matrix of measuring point coordinate system relative to the reference coordinate system is derived, and pose errors of linear vibration table are drawn by using appropriate test method and data process method.Based on perpendicularity between inner and outer framework, the error model equation of PIGA is derived,and the relationship between the error model coefficients of PIGA and the corresponding errors is pinpointed. By the analysis of PIGA mechanism and its specific application, the simplified error model of PIGA used in the experiment is established, and the corresponding error model is established on the condition of considering the cross-term.In order to improve the test precision of PIGA, by establishing a series of coordinate systems, using homogeneous transformation method as a tool, the sensitive input of PIGA is derived, which contains specific forces and angular rates about the input axis. In order to improve the calibration accuracy of PIGA’s high terms error model coefficients, two test methods which are based on whole period of linear vibration and whole period of PIGA are designed, and they are used to test PIGA on the precision linear vibration table. By comparing the two test methods and analysising the calibration results’ error, factors of PIGA error model coefficients’ calibration accuracy are inferred, then test method and conditions of improving the calibration accuracy are proposed.The corresponding test methods are used to identificate the related coefficients of the PIGA error model in consideration of the linear vibration table’s parasitic rotation and waveform distortion respectively, and the results of not considering the parasiticrotation or waveform distortion is compared with, then the effect of the parasitic rotation has on the quadratic and cubic term error model coefficients is confirmed.In order to improve the quadratic coefficient’s identification accuracy of PIGA error model, the identification method of the cross-quadratic term coefficient is designed, which has a great effect on the calibration of PIGA error model coefficients.