Force Analysis Of The Redundantly Actuated Parallel Mechanism 2r(P)Under-Barr+P Considering Different Control Methodologies

In the problem of driving forces/torques distribution of the redundantly actuated parallel mechanisms (PMs), although numerous optimization analysis methods, including the minimum input torque method and minimum energy consumption method have been proposed so far, however, the actual control modes of the actuators were not taken into account among the existing methods for the above problem. Therefore, the present study comprehensively considers both the elastic deformation and actuator's displacement of each limb, proposes the idea of "displacement coordination" and establishes the overall displacement coordination equations of the mechanisms. Three different control methodologies of the redundantly actuated PMs, including the full-position methodology, hybrid position-force control methodology and full-force methodology, are studied. For each control methodology, the correlation among the driving forces/torques, actuators' displacements, external loads and limbs' stiffness are discussed. An experimental platform of a redundantly actuated PM is built, and the corresponding test investigations for three control methodologies are conducted. In the present study, different control methodologies of the redundantly actuated PMs are considered for the first time, the principle of the dynamic coordination distribution is revealed in different methodologies, which have important reference values for design of coordinated motion control strategy of such kind of mechanisms. (C) 2021 Elsevier B.V. All rights reserved.