Abstract:

A method based on Schur decomposition and unscented Kalman filter (UKF) is designed to identify the parameters of the Stewart coupling model. The state model, measurement model and observability are given. The UKF is adopted to determine the payload position and attitude. The attitude measurements are used in the UKF to correct the angular velocity error so that the estimation accuracy and convergence speed of the angular velocity can be improved. The payload generalized displacement, generalized velocity and generalized acceleration should be obtained. The parameter decoupling method is designed and the least squares method is used to identify the dynamics parameters. Numerical simulations results indicate that the angular velocity is estimated accurately by the UKF and the stiffness identification errors of the Stewart six struts are less than 0.01.

Key words: Stewart ultraquiet platform, Position and attitude determination, Unscented Kalman filter (UKF), Parameter identification