Research Of Rotation Demodulation Technology For Autonomous Deformation Measurement System Based On Single-axis Rotation INS

In autonomous deformation measurement system, which is based on single-axis rotation inertial navigation system(INS), how to demodulate the real ship angular velocity from the output of the laser gyros of the single-axis rotation INS is the key point. To solve this problem, this essay has done some research on the demodulation algorithm, and has analyzed the possible error factors during the demodulation process that may influence the demodulation accuracy and the deformation measurement accuracy, and has analyzed some main error factors and the form of their influences on deformation measurement in theory. It will provide some reference for the design of single-axis rotation INS and deformation measurement system. The main task of this essay is as follows:1. Researched the demodulation algorithm of the gyro output of ship deformation measurement system based on single-axis rotation INS, compared the demodulation method based on direction cosine matrix and the demodulation method based on quaternion both in theory and in simulation.2. Researched the effect of errors such as gyro bias, scale factors, non-orthogonal installation error, angular encoder measurement error, shaft orientation error on ship deformation measurement.3. Reformed the Kalman filter formulations for ship deformation measurement, and made it possible to estimate the gyro biases under the condition of single-axis rotation demodulation.4. Researched the shaft orientation calibration method both in static status and mooring status, and verified their validity through experiments.5. Deformation measurement experiments both under no rotation modulation and single-axis rotation modulation were conducted, and the results showed the feasibility of ship deformation measurement method based on single-axis rotation INS.