A method to realize attitude algorithm module in strapdown inertial guidance is presented. Based on the digital signal processor and quaternions

the attitude algorithm module in strapdown inertial guidance is designed. Firstly

the principle of trapdown inertial guidance

the attitude algorithm and the numerical method is introduced. The circuit and software of attitude algorithm is designed. The test result shows

when the increment is less than 5°

the relative error is less than 0.005286％ with 4 order Runge—Kutta; the algorithm time is less than 36s with TMS320C6713B. It can meet the demands of trapdown inertial guidance.