Abstract: With higher requirements for accuracy,rapidity and endurance on navigation system used in stationary and marine plant,rotating inertial navigation has become one of the most important technical strategies that can fulfill these requirements.Indexing accuracy,acceleration and deceleration smoothness,and launch speed of the indexing mechanism in rotating inertial navigation are the key factors which will affect the precision of posture demodulation.According to the characteristics of initial alignment,index modulation and posture demodulation,analysis indicates that rotating inertial navigation demands for smoothness of speed and controllability of acceleration.The influence of the segmented speed control method and S-curve method on the navigation accuracy is analyzed.Simulation and experiments show that the smoothness of speed and controllability of acceleration and deceleration during rotation procedure,improvement of rotation precision and symmetrical process of acceleration and deceleration is achieved,and the adverse effect on the reliability of motor brought by excessive speed overshoot is avoided.

Key words: Rotating inertial navigation, Acceleration and deceleration motor control, S-curve, Navigation accuracy