Application of the design for control approach for the integrated design and control of parallel robots

Abstract

To effectively control a complex mechanical structure for precise performance, a model-based type of controller is usually desired. In cases of controlling parallel robots, however, the iterative computation due to the complexity of the dynamic models can result in difficulties in controller implementations and system stability analysis. To avoid this problem, simplified dynamic models can be obtained through approximation, nevertheless, performance accuracy will suffer due to simplification. This paper suggests applying the effective Design For Control (DFC) approach to handle this problem. The underlying idea of the DFC approach is that, no matter how complex a system is, as long as its mechanical structure can be judiciously designed such that it results in a simple dynamic model, a simple control algorithm may be good enough for a satisfactory control performance. Through out the discussion in the paper, the integrated design and control of a two DOF parallel robot is studied as an illustration example. Experimental validation has demonstrated the effectiveness of the DFC approach.