An enhanced scheme for the model-based control of robot manipulators

It has become common practice, in recent years, that the model-based computed torque method is adopted for the tracking control of robotic manipulators. However, high precision tracking is possible only in the case of perfect or almost-perfect modelling. In this paper, a novel scheme is proposed to enhance the existing model-based method. It is based on the combination of the classical serial pre-compensation of the computed torque method and a model-based parallel post-compensation approach. The resulting system has a simple structure with good robustness. Several problems associated with the practical implementation of the developed method are addressed. Numerical examples and comparative studies demonstrate that the presented approach can outperform the conventional method.