Abstract:The multi-degree-of-freedom hydraulic manipulator is a complex electro-mechanical-hydraulic nonlinear system with multiple inputs and multiple outputs, strong nonlinearity and strong coupling. The precise control of the hydraulic manipulator is a very challenging task.A robust integral of the sign of the error (RISE) based on virtual decomposition was proposed for high-precision tracking control of hydraulic manipulator systems. Considering the dynamic coupling between the three joints, the dynamics of the hydraulic actuator and the friction effect, the kinematic and dynamic mathematical model of the hydraulic manipulator was established based on the virtual decomposition. Based on the virtual power flow to make the subsystem and the whole system satisfy L2 and L∞ stability, a virtual control method was designed. Then, the coupling effect between joints was integrated into the robust controller design, and a robust integral of the sign of the error control method based on virtual decomposition was developed, which further enhanced the joint position tracking ability. Based on Lyapunov theory, it is proved that the control method can achieve asymptotic convergence of position tracking error. The comparative simulation results show that the proposed robust integrator controller based on virtual decomposition has excellent asymptotic tracking performance.