Importance of cable vibration in dynamics of cable-driven parallel robots

International audienceIn this paper, an original method to analyze the vibrations of Cable-Driven Parallel Robots (CDPRs) is presented. A nonlinear oscillating model of CDPRs able to capture the dynamic behavior of the cables is developed from the Dynamic Stiffness Matrix method. The system modeling considers the dynamic load deformation behavior of the cables, the end-effector vibrations and their coupling through the computation of a frequency-dependent dynamic stiffness matrix. There results new and numerous cable vibration modes, as well as nonlinear end-effector modes. System modeling and methods analysis are firstly illustrated with reference to the two degree-of-freedom (DOF) model of a cable-mass system. Then both numerical investigations and experimental analyses carried out on a 6-DOF CDPR prototype suspended by 6 cables give highlights about the effect of the cable modes on the end effector response. The paper ends with a discussion on the main perspectives on analysis and reduction of vibrations of CDPRs