Error Analysis Of Gyro Accelerometer Tested On Precision Centrifuge

Gyro Accelerometer is widely used in strategic missile guidance, the calibration accuracy of its model coefficients affects navigation accuracy directly, the nonlinear terms of high-precision PIGA is usually calibrated on the centrifuge. Therefore, the analysis on the affect of the error of precision centrifuge on the calibration accuracy of model coefficients of PIGA is of certain theoretical and great practical value.Error model equation of PIGA is derived considering perpendicularity between inside and outside framework. The deduced error terms includs static error coefficients, dynamic error coefficients and mixed error coefficients, which have explicit physical meaning. This provides a theoretical basis for further improving the accelerometer manufacturing process.Taking into account all displacement and attitude error sources in the precision centrifuge, homogeneous transformation matrix between measured accelerometer coordinates system and geographic coordinates system is derived. The angular rate input and the specific force input of PIGA were calculated according to the characteristics that PIGA can be sensitive to both specific force and angular rate on the input axis simultaneously, of which the specific force input includes harmonic acceleration, the acceleration of gravity and Coriolis acceleration components. It provides a basis for designing the test plan of PIGA on t precision centrifuge and analysis of the impact of precision centrifuge errors on the model coefficients calibrition accuracy. Various error sources on the PIGA output calculation on given test conditions.In order to guarantee the nonlinear term error model calibration accuracy of PIGA in the centrifuge dynamic test, bias and scale factor are determined through test in lg gravitational field, which lay a the foundation for the nonlinear coefficient test; the quadratic model coefficients are calibrated by 12-position tumble test in lg gravity field, and the scale factor is corrected.With the exact bias, scale factor and specific force input of PIGA, dynamic test on centrifuge with a counter-rotating platform was engaged, using least square method, PIGA error model containing centrifuges pose errors and the Coriolis acceleration is identified, which improve the calibration accuracy of the model coefficients; identification methods of quadratic and cubic term model coefficients of PIGA were given to isolated effects of other factors on the calibration accuracy, which lay foundation for the analysis of the contribution of error source to calibration.At the last part of this article, the influence of centrifuge errors and Coriolis acceleration on nonlinear terms of PIGA model coefficients is derived and calculated in dynamic tests on precision centrifuge from a example, which lay foundation for the compensation of calibrated error coefficients and provides the basis for improving the stability of the centrifuge displacement and attitude error and the accuracy of test.