Research On GPS/IMU Integrated Measruement Method Of Spinning Projectile Motion Parameters Based On Kalman Filter

The precise measurement of the airctaft motion parameters is a necessary prerequisite to control the flight attitude and trajectory. Motion parameters measurement and estimation problem of the spinning projectile with a certain spin rate projectiles are studied.At first, this paper summarizes the basic principle of Strapdown Inertial Navigation Systems; deduces the nonlinear dynamic equation of motion parameters (attitude angle, velocity, position) in detail; constructes the spinning projectile motion parameters simulation measurement system combining with six degrees of freedom exterior ballistic model, and discusses the method of generating motion parameters simultaneously. Secondly, according to the linearization idea, linear error state equation and measurement equation system were derived and the loosely coupled integration model of integrated GPS/IMU’s measurement system was established. Then, indirect and output correction method of linear Kalman filter and extended Kalman filter (EKF) were used to estimate motion parameters based on the loosely coupled integration model. The simulation results and theoretical analysis demonstrate that the estimation results of the two methods will diverge when increasing the rotating rate. Finally, this paper estimates motion parameters of spinning projectile by using the square-root central difference Kalman filter (SR-CDKF), the simulation results show that SR-CDKF can still maintain high estimation accuracy in high spin rate projectiles. The research results provide an effective method for motion parameters measurement and estimation problem of high dynamic aircraft.