Fuzzy identification of nonlinear parameters based on optimal control theory

Time-varying physical parameters of structure joint have important value for structure dynamics characteristic research and applying in practical engineer, so, an identification method of time-varying nonlinear physical parameters of structure joint is presented. The dynamic mode of every substructure is used and the nonlinear force of structure joint is regarded as an input variable of the mode. The nonlinear force of structure joint is identified by using optimal control theorys and fuzzy math methods. The response of structure joint is computed by substructure methods. The nonlinear force is fitted by least square methods and time-varying physical parameters are computed. Simulation result shows that the method is effective.