Evaluating cable tension distributions of CDPR for virtual reality motion simulator

Abstract

This paper presents a study on modeling, analysis, and control of an over-constrained Cable-Driven Parallel Robot taking into account the deformation of the cable transmission system due to the elastic model of the transmission mechanism and the affection of tension distribution for cables. The Cable-Driven Parallel Robot is used for a virtual reality motion simulation system with a simulation cabin mounted on a moving platform. A nonlinear cable length controller with tension feedback is designed to control the cabin to move along a trajectory extracted from the virtual simulated environment. The tension distribution algorithm is integrated into the controller to compensate for the dynamic error caused by the two redundant cables and the elastic characteristic of the transmission mechanism. The tensions are calculated based on the constraints of the workspace, the structure of the system, and the force limits of actuators. The cable tension feedback control algorithm was tested on the concept Cable-Driven Parallel Robot, the experimental results show that the joint trajectories meet the desired moving trajectory with high accuracy, and the cable tensions are controlled in the optimal region to ensure safety and save energy, but still suitable for the control requirements of the virtual reality motion simulator system.