A Workspace Analysis of a Overconstrained Cable-Based Parallel Manipulator by Using Interval Analysis

Mechanical structure of a cable-based parallel manipulator consists of a moving platform, witch is called end-effector, and a base. These two elements are connected by multiple cables. Indeed, the end-effector is operated by motors that can extend or retract cables. Cable-based parallel manipulators are structurally similar to parallel ones but they have some advantages, if compared to classical parallel manipulators. They have large workspace and few moving parts, which gives good inertial properties. These characteristics make them suitable for applications which require high velocities and accelerations [Melchiorri, 2005]. Other characteristics are high payload-weight ratio, transportability and economical construction. The mechanical system can have a simple structure such that it is easy to manufacture at low cost [Barrette and Gosselin, 2005], [Merlet, 2004] and [Riechel et al., 2004]. It is also possible to obtain re-configurable manipulators relocating connecting points of the cables [Gorman et al., 2001] or actuator position [Merlet, 2006].