Parameter identification method of motion platform of helmet mounted display servo system

The nondeterminacies and time-varying characteristics of parameters for motion platform of helmet mounted display servo system(HMDSS)were analyzed,the identification processes of continuous-discrete extended Kalman filter(CDEKF) and continuous-discrete square-root unscented Kalman filter(CDSR-UKF)were derived,the parameter identification model of motion platform of HMDSS was presented based on the system dynamics model,and the identification effects of CDEKF and CDSR-UKF were compared by simulation.The mutation experiment of parameters for motion platform was designed and implemented to verify the practicability of CDSR-UKF.Simulation result indicates that the standard error ratios,convergence time ratios and root mean square error ratios of CDEKF to CDSR-UKF are 1.9-6.3,1.0-27.7and 1.4-11.0,which means that CDSR-UKF has higher identification precision,stability and convergence velocity than CDEKF.The average convergence time of CDSR-UKF is about 0.002 s,so CDSRUKF has better capacity of real-time identification.The online estimation error of CDSR-UKF is less than 10%,and the convergence times against large parameter mutation and normal parameter mutation are about 0.30 sand 0.04 srespectively,so CDSR-UKF can well trace changingprocesses of identification parameters and satisfy parameter identification requirements of motion platform of HMDSS in normal usage environment.5tabs,30 figs,26refs.