Influence of pulley kinematics on cable-driven parallel robots

In this paper the modeling of a pulley mechanism for cable-driven parallel robots is presented. In many works, the proximal anchor points of the robots are simplified to be ideal points. Real cables achieve reasonable life time only when a minimum bending radius is exceeded. Therefore, pulley mechanisms have to be used which in turn require the extension of the kinematic modeling. In this paper a kinematic model for a pulley mechanism of the winches is revisited. Then we derive a corrected structure equation and compare the different results from the extended model with the estimation from the simplified standard model with respect to kinematics transformation, workspace, and force distribution.