The Adaptive Robust Control of Deep-Sea Hydraulic Manipulator With Velocity Observer

In this paper, the adaptive robust control method with a velocity observer is proposed to control a deep-sea manipulator. The parametric uncertainties and external disturbances make the linear controller invalid, and hydraulic actuator’s dynamics can’t be neglected because hydraulic system’s complex nonlinearity might lead to vibration. To solve the problem, an adaptive robust controller which can also compensate the interactive dynamic effects between manipulator links is developed. The deep-sea manipulators are only installed with angular sensors, so an observer providing the smooth angular velocity estimation is designed. By using the Lyapunov approach, the proposed controller can be proved asymptotically stable for trajectory tracking. The contrast experiments are conducted on a deep-sea hydraulic manipulator, experiment results show the control algorithm could provide a fast, high accuracy tracking, and guarantee the tracking performance when subjected to payload change or a range of different reference signals.