The influence of different factors on the dynamical workspace was analyzed for the parallel robot system in which many robots collaboratively tow the same object by cables.First,the dynamic model on the towing system was established using force spinor balance equation.Second,a solution for closing the force spinor of the underconstrained system was given using the virtual cable method.Third,the dynamical workspace and quality of the dynamical workspace of towing system were analyzed.Finally,the dynamical wo...