The study of nonparameter identification algorithm based on cos-pseudorandom

Aimed at solving the problem that there exist the finite states for on-line non-parameter identification of electro-hydraulic servo valves with M-pseudorandom signal, cosine pseudorandom signal with continuous state is introduced as input signal. Theoretical proof indicates that cosine pseudorandom signal possesses best autocorrelation for different signal amplitudes and identification accuracy of servo valve is not influenced by measurement error and DC component signal. Moreover, the proposed method has the merits such as high accuracy, small amount of calculation, and more test frequency points for the same sequence length. Then the parameters selection method of cosine pseudorandom signal is analyzed for electro-hydraulic servo valves, and the experimentation tested that the cosine pseudorandom signal is the optimization signal in the system identification.