Optimal damping algorithm design in inertial navigation system

In order to restrain the Schuler oscillation in inertial navigation system (INS), external velocity measurement was used as a reference to design optimal damping algorithm based on the Kalman filter. The error models of INS horizontal loops were studied according to its control model and Kalman filters were adopted to estimate the platform misalignment errors, velocity errors and gyro drift. Then based on the optimal control thought, feedback correction algorithm was designed and the estimate was put forward to damp Schuler oscillation and Foucault oscillation. Compared with the traditional damping network, optimal damping algorithm developed the transient response characteristics, in addition it could be used to estimate and compensate gyro drift. Simulation results shown that this algorithm could effectively suppress the Schuler oscillation and improve accuracy of inertial navigation system.