OPTIMAL FEEDBACK LINEARIZATION CONTROL OF A FLEXIBLE CABLE ROBOT

Abstract

 In this paper the flexible cable robot tracking is controlled using optimal feedback linearization method. Feedback linearization is used to control the robot within a predefined trajectory while its controlling gains are optimized using LQR method to achieve the maximum payload of the endeffector in presence of flexibilities. Required motors’ torque and tracking error caused by flexibility uncertainties are calculated for a predefined trajectory of an under constrained cable robot with six Degrees of Freedom (DOF) and six actuating cables while its cables are considered elastic. Robust controller is also designed and added to the controller to ensure the accuracy and stability of the system and cancel any disturbing effects of the uncertainties. A series of analytic simulation study is done for the mentioned spatial cable robot to show the flexibility effect on dynamic performance of the robot and also prove the superiority of the proposed optimal control strategy to compensate these flexibilities. Finally the results are compared and verified with experimental results of the cable robot of ICaSbot to verify the proposed controlling strategy for controlling the mentioned flexible robot and also prove the correctness of the simulations.