Shaft orientation error compensation of single-axis rotation INS in ship deformation measurement system

In the ship deformation measurement system, which is based on the single-axis rotating modulation inertial navigation system, the shaft orientation error is one of the important factors that affect the accuracy of rotation demodulation process and ship deformation measurement. A shaft orientation error compensation method based on quaternion was proposed in this article. The coordinates of the rotation axis of the turntable was calibrated in the reference frame of the inertial measurement unit, and then converted to quaternion together with the output of the gyros and the rotation angle of the shaft, thus calculate the angular velocity of the ship in quaternion form. Simulation results show that the ship deformation measurement accuracy can be significantly improved after error compensation.