Calculation of the cable-platform collision-free total orientation workspace of cable-driven parallel robots

The large workspace of cable-driven parallel robots is one of their main benefits over conventional parallel robots with rigid links. Therefore, it is crucial to measure its size and analyze its constraints. One of the limits are collisions between the cables and the platform of the robot. They can damage the robot and cause malfunctioning of its control algorithms. In the literature, methods for the detection of this collision type only consider the constant orientation workspace and are ill-suited for platform geometry data supplied from a CAD model. This paper presents a new approach for the approximation of the cable-platform collision-free total orientation workspace with various platform orientation sets. The collision detection is based on a convex collision cone data structure that precisely extracts the relevant information for collision detection from the platform geometry data. This method is compatible with various workspace approximation algorithms to facilitate its integration into the design process of cable-driven parallel robots. It is tested on the IPAnema 3 cable robot geometry and its performance is evaluated in terms of computation time