Redundant sensor based control of the 3RRR parallel robot

In this paper, a control approach to increase the accuracy and precision of a 3RRR parallel robot based on the use of extra sensors in the passive joints is proposed. For that purpose, a redundant dynamic modelling approach and a control scheme based on the redundant data is presented in this paper. The proposed approach, the Extended CTC, introduces redundant data directly in the controller by means of a proper dynamic model, providing better dynamic performance than classical approaches in presence of model parameter uncertainties. The effectiveness of the control law is demonstrated using two approaches. Initially, a sensitivity based analysis is performed in order to analyze the relative robustness of the proposed approach. Secondly, results are validated by a set of simulation experiments in the 3RRR parallel robot in presence of randomly introduced model parameter uncertainties. (C) 2012 Elsevier Ltd. All rights reserved.