Observer based quasi-static deformation compensation control for three-link rigid-flexible manipulator

In this paper, a new method of observer based quasi-static deformation compensation control is proposed to track the end position trajectory for a three-link rigid-flexible manipulator with a large payload. Firstly, an observer is developed based on the model of the three-link rigid-flexible manipulator to estimate the vibratory modals and their time derivatives, which are practically impossible to measure. Meanwhile, the vibration can be suppressed by feedbacking the estimated values to the controller. Secondly, a sliding control scheme is put forward to track the end position trajectory. Thirdly, the quasi-static deformation compensation algorithm by compensating the desired joint angles is come up with considering the deformation of the flexible manipulator. The end position trajectory will be tracked precisely when the vibration is suppressed and the desired joint angles are compensated. Finally, simulation results demonstrate the effectiveness of the proposed method.