An automatic compensation method for states switch of strapdown inertial navigation system

To improve the accuracy of strapdown inertial navigation system of ship in long time, it should works in damping state when the ship has a constant velocity, and in free damping state when the velocity of ship is varying. Thus the SINS may switch frequently between the damping state and the free damping state, which degrades its performance. To reduce the overshoot in states switch, instantaneous velocity of strapdown inertial navigation system at switch moment is compensated to the damping network in this paper. Simulation results show that the proposed method can not only reduce the velocity error overshoot, but also reduce its steady-state error, and the precision of the system can then be improved.