Parameter identification and controller design for flexible joint of Chinese space manipulator

Manipulators with flexible joints are widely used as the space manipulators, whereas the elasticity of flexible joint leads to poor dynamic performance. To solve the influence of elasticity, the paper is to establish the model of flexible joint, identify the parameters, and design the controller. The off-line methods are applied to identify the current coefficient and the parameters of flexible joint model. The controller is designed based on the theory of state feedback and pole assignment. To make the calculation of controller gains easier, more precise and more intuitive, the nominal stiffness is introduced. The simulation results and the experimental results indicate that the proposed controller can improve the dynamic performance and reduce the vibration of the manipulator compared with the traditional PD controller.