Research on bilateral control strategy of tele-operation 4-DOF manipulators with force tele-presence

Tele-operation consists of movement control and Force control, of which the key is tele-presence. This paper presents the components of the 4-IJOF tele-operation system, displacement and force servo control principle. The manipulators are driven by hydraulic servo system. Because of the features of the common symmetry servo valve, the master manipulator can´t drive the hydraulic cylinders directly and force information of the master manipulator is needed through the controller. This process affects the response speed. In order to improve this of response delay, the force and displacement deviation signals of the master and slave are adopted to control the slave manipulator, and the force feedback adopted the displacement deviation signals of the slave and the master manipulator, this new control strategy is called force symmetry servo bilateral control strategy. This new control strategy enhances the response speed of the master-slave control system, and the force tele-presence is efficient. Force reflecti on servo and force symmetry servo bilateral control strategies are individually tested on the master-slave system to study the tele-operated force feedback bilateral servo control. Through theoretical analysis and experimental tests, it is proved that the master-slave manipulator structure is reasonable, and the force symmetry servo bilateral servo control strategy has satisfied control capabilities.