Position regulation under position dependent speed limit of a torque-driven nonlinear rotational mechanism model

In control systems, actuators always have (in some degree) physical limitations in their capabilities. In the case of mechanisms (robots included), actuators (typically electrical motors) have also limitations at which can operate successfully and safely without damage, for instance in torque and velocity. This paper addresses the shaft displacement control (position control) of a torque-driven nonlinear gravity unbalanced mechanism but with limited speed capability. A nonlinear dynamic controller that takes care of the actuator maintaining its operation within safe speed limit is proposed.