A Novel External Rate Sensing Algorithm for Gyrowheel Based on Jacobi-Anger Expansion

Gyrowheel is an attitude determination and control instrument for small spacecrafts. Large tilts of its rotor and de-tuned spin rates lead to complex and nonlinear dynamics as well as difficulties in measuring external angular rates. Thus, the problem of angular rate sensing with the gyrowheel is investigated, and a novel external rate sensing algorithm is developed in this paper. In an effort to avoid linearization errors of the traditional method, the low-frequency characteristics of the gyrowheel dynamics are extracted by utilizing the Jacobi-Anger expansion. A simplified low-frequency model is obtained based on the particle swarm optimization algorithm, and a practical rate sensing algorithm for the gyrowheel is constructed. Validation simulations and experiments on a gyrowheel prototype show that the proposed algorithm is significantly superior to the traditional one especially under large tilt conditions.