Design of Planar Cable-Driven Robot with a Full Rotation

This paper investigates the unlimited orientation problem of planar cable driven parallel robots (CDPRs) where achieving one rotation or more than a full rotation of the end-effector is challenging. A discrete algorithm is developed in order to compute the translational and rotational workspace of CDPR based on the positive cable tensions condition. For each position on the discretization grid, the rotation angle of the end-effector (EE) is incremented until a failure of the robot equilibrium, which identifies the maximum reachable rotation angle. The implemented algorithm was first applied to the classical 4-cable 3-Degree of Freedom (DoF) CDPR where the total orientation is found to be restricted. To obtain an unlimited orientation of the EE, a new design of a CDPR was introduced. This new design has 6 cables and 3-DoF. This new architecture was shown to allow the EE to perform 360° of rotation for a large part of the translational workspace. This result can be useful when large orientation angles are required.