Abstract: Stewart platform driven by electro-hydraulic system is a multi-input and multi-output baroque parallel mechanism, in which serious load-coupling phenomenon occurs between channels. Generally performance parameters of each channel of platfrom are computed or identified according to the theory of servo-valve controlling cylinder system, the results obtained are different from practical operation conditions greatly, which affects the design and performance improvement of the platform control system severely. In order to solve the above problem, a kind of closed-loop identification algorithm of Stewart platform is designed on the basis of Levenberg-Marquardt optimization algorithm and a six-dimension uncorrelated exciting signals, and the experimental research on parameters identification is done on Stewart platform driven by electro-hydraulic test prototype. Experiment results show that the identification algorithm can identify the platform channels performance parameters precisely, and satisfactory identification results are obtained.

Key words: Closed-loop identification algorithm, Electro-hydraulic servo control system, Identification model, Stewart platform