Abstract: Three-axis hydraulic simulator has the characteristics of moment coupling among frames, complex friction moment disturbance and system parameter perturbation. This paper proposes to equal the term of coupling to outer disturbance, and uses the dynamic full-order sliding mode variable structure controller with integral compensation to make three-axis move within their own sliding modes and realize the aim of decoupling and robust to disturbance and parameter perturbation. Simulations and experimentations show that the proposed approach has a quite accuracy servo-tracking result.

Key words: three-axis hydraulic simulator, decoupling, variable structure control, full-order sliding mode