Planar Cable-Direct-Driven Robots: Part II — Dynamics and Control

Abstract

Abstract A hybrid parallel/serial manipulator architecture was introduced in a companion paper where the translational freedoms are provided by a cable-direct-driven robot (CDDR) and the rotational freedoms are provided by a serial wrist mechanism. While the companion paper presents kinematics and statics, the current paper presents a dynamics model and simulated control for planar CDDRs. Examples are presented to compare the planar 3-cable CDDR with one degree of actuation redundancy and the 4-cable CDDR with two degrees of actuation redundancy. It was found that the 4-cable tracking error was worse than for the 3-cable case, due to increased inertia with an additional actuator. Also, the controller architecture considers including and not including a feedforward reference acceleration term with the overall mass matrix; the performance of the controller with the feedforward term is clearly preferable.