A fuzzy control internal damping algorithm in a long-endurance inertial navigation system

An internal damping algorithm was proposed to solve the problem of the Schuler oscillation amplitude of inertial navigation system (INS) errors diverging with time in long-endurance applications. A second-order damping network was designed where a fuzzy controller was used to determine the current motion states and data fusion strategies were developed to accomplish conversion of INS between the damping state and non-damping state. The INS velocity at the moment when the damping conditions are satisfied was used as a reference to ensure the working independence of INS, getting rid of the dependence on external measurements. The marine experiment results show that the proposed algorithm can effectively restrain Schuler oscillation amplitude in INS errors, thus improving accuracy of INS in long-endurance applications.