Deriving suitable models for model-based control design of a parallel manipulator with flexible components

Abstract

Parallel manipulators are more energy-efficient and present higher speed/acceleration ratios when compared with serial manipulators. Moreover, reducing their components’ inertia can further improve these performance criteria. However, this design alternative could induce vibrations due to its lighter components. In this case, model-based control design strategies can help the designer to meet high-performance requirements. These strategies require limited-sized models, while the methods for modeling system’s flexibilities usually yield large-sized models. Therefore, strategies for reducing the size of these large-sized models should be employed. In this manuscript, a two-step model reduction strategy is proposed to derive suitable models for control design. This proposal preserves all rigid modes and selects the most relevant flexible ones. An Linear Quadratic Gaussian is designed for a flexible 3RRR parallel manipulator using a limited-sized model. This model-based control strategy is evaluated in a flexible multibody environment demonstrating the proposal’s viability.