System separation algorithm of acceleration-sensitive drift coefficients of skewed-installation liquid floated gyro

Abstract:

To achieve monitoring acceleration-sensitive drift coefficients DID_s of the skewed-installation liquid floated gyroscope in IMU(inertial measurement unit) on the condition of free disassemble, a system level separation algorithm using calibration parameters of inertial measurement unit is put forward. By the analysis of structure and skew installation principle of liquid floated gyroscope, the paper gives the liquid floated gyroscope and its system’s error models. Then based on error models and ever-obtained error parameters of skew inertial measurement unit,the system level separation algorithm of acceleration-sensitive drift coefficients is designed. It is unnecessary to design complex calibration tool when using this algorithm, and also without removing liquid floated gyroscopes from inertial measurement unit, these improvements can reduce error accumulations, so that the precision of parameters’s separation is high, and the residual error is small. The deviation between the single gyro separation algorithm and system level separation algorithm is smaller than 1.301×10-3(°)·(h·g₀)-1, which fully meets the requirements of high precision inertial measurement unit to acceleration-sensitive drift coefficients of liquid floated gyroscopes in engineering application.