A Sliding Mode Control for a Planar 4-Cable Direct Driven Robot

Cable Direct Driven Robots (CDDRs) are structurally similar to parallel robots but these are formed by replacing all the supporting rigid legs with cables, where the motion of the end-effector is controlled through cables which are pulled from actuators placed off-board the robot. CDDRs control is a challenge due to the physical characteristics of cables because these can only apply tensile forces and no compression. The aim of this paper is to present a Sliding Mode Control (SMC) for a Planar 4-Cable Direct Driven Robot, SMC is designed in order to obtain fast system response and the robustness against the model uncertainty. For the purpose of validating the proposed controller the trajectory tracking test and model uncertainty test were performed. Simulation was carried out for the proposed controller and the results were compared with a PD Controller in terms of Integral Square Error (ISE) index.