SINGLE DEGREE OF FREEDOM PASSIVE BILATERAL HYDRAULIC TELEOPERATION USING A PASSIFIED TWO-STAGE SERVO-VALVE

摘要

Passive machines possess the inherent property that they can interact stably with other passive systems. A problem with applying the concept of passivity to ensure interaction stability of hydraulic machines is that the latter are not intrinsically passive. In previous work, a passifying control was developed to ensure that a single-stage directional control valve behaves like a passive two-port device. The passified valve was used in passive teleoperation of a hydraulic actuator. Unfortunately, single-stage valves are limiting in their flow rate and bandwidth capabilities which can be remedied using multistage valves. In this paper, we first review a passifying control which ensures that a non-passive two-stage pressure control servo-valve behaves like a nearly-passive two-port device. A teleoperation controller that uses the passified two-stage valve is then developed to ensure 1-DOF coordinated motion of the passive hydraulic actuator system (slave) and a force-feedback joystick (master). The control also guarantees the passivity property of the teleoperation system.