Identification of the inertial parameters of underactuated Cable-Driven Parallel Robots

Cable-Driven Parallel Robots (CDPR) employ extendable cables to control the pose of an end-effector (EE). If number is smaller than degrees freedom EE, and have no special arrangement reducing EE freedoms, robot underactuated, underconstrained: as a consequence, preserves some freedoms even when all actuators are locked, which may lead undesirable free motions. This paper proposes novel methodology for identification inertial parameters these robots. Inertial useful, example, in application feedforward techniques. The main merit our approach that it does not require force or torque measurements, only subset kinematic variables needs be measured. method consists internal-dynamics equations along free-motion trajectory, also referred self-motion zero dynamics. results over-determined system linear (the Free-motion Internal-Dynamics Identification Model, FIDIM); said solved according Total-Least-Square technique. trajectories optimal purposes investigated experimentally tested on 4-cable robot. FIDIM then applied, statistical analysis performed, experimental cross-validated against additional trajectories.