A Cable-Driven Parallel Robot With Full-Circle End-Effector Rotations

Abstract

Cable-Driven Parallel Robots (CDPRs) offer high payload capacities, large translational workspace and high dynamic performances. The rigid base frame of the CDPR is connected in parallel to the moving platform using cables. However, their orientation workspace is usually limited due to cable/cable and cable/moving platform collisions. This paper deals with the design, modelling and prototyping of a hybrid robot. This robot, which is composed of a CDPR mounted in series with a Parallel Spherical Wrist (PSW), has both a large translational workspace and an unlimited orientation workspace. It should be noted that the six degrees of freedom (DOF) motions of the moving platform of the CDPR, namely, the base of the PSW, and the three-DOF motion of the PSW are actuated by means of eight actuators fixed to the base. As a consequence, the overall system is underactuated and its total mass and inertia in motion is reduced.

On the Cable Actuation of End-Effector Degrees of Freedom in Cable-Driven Parallel Robots

“…The designs proposed in [7,9] are meant to modify a CDPR cable configuration by selecting a cable which is doubled. Both cables from this doubling are driven by individual winches.…”

“…In the case of the robot presented in [7,8] with 6 degrees of freedom and 8 cables, cables are assembled by pairs which are routed towards 4 actuated drums installed in the platform. Middle points of fixing point pairs shape a square.…”

“…It uses a mechanism embedded into the mobile platform actuated from the CDPR base by a cable loop and does not suffer from parasitic motions. Moreover, full unlimited 3-DOF rotations are obtained in [7,8] by using an embedded spherical wrist implemented with omni-wheels.…”

“…This analysis considers one internal EE DOF but could be generalized to more DOFs in future works. From this perspective of wrench modification, designs suggested in [4,7,8] are discussed.…”

Unsupervised Neural Network Based Forward Kinematics for Cable-Driven Parallel Robots with Elastic Cables

“…The pre-planned path used for verification purpose is chosen to be within robot workspace (based on CRAFT [13] with an upper and lower bound on cable tensions equal to t = 86 N and t = 1 N respectively). The MP mass is named m E .…”