Implementation of tightly coupled GPS/INS navigation algorithm on DSP

In order to verify the real-time capability and precision of the tightly coupled GPS/INS(Inertial Navigation System) navigation algorithm, test platform using the high performance floating-point digital signal processors produced by TI as CPU was designed for integrated navigation system. It could simulate inertial measurement unit and GPS receiver and complete many navigation algorithms efficiently. In the test, pseudo-range and pseudo-range rate were used as the measurements of the Kalman filter in the tightly coupled GPS/INS navigation algorithm. The U-D covariance factorization with sequence processing algorithm was applied to Kalman filter. The test results indicate that the precision of tightly coupled navigation algorithm is an order of magnitude higher than the loosely coupled navigation algorithm using position and velocity as measurements. In addition, the U-D covariance factorization with sequence processing algorithm has good numerical stability and can effectively reduce the computation time and data storage.