Concepts of model-based control and trajectory planning for parallel robots

The paper deals with the concepts of model-based control and trajectory planning intended for industrial parallel robots. These robots are characterized by very good dynamical properties arisen from small number of moving masses in comparison with conventional configurations. In the paper, multi-level (hierarchical) control will be investigated. It can be specified as a model-based control providing positional and speed loops with addition of fast low-level current-loop control. As a suitable representative of model-based control, predictive control is considered. Described concept can offer more possibilities to manage the control process than usual cascade control. Finally, the paper outlines two different concepts of trajectory planning. The first concept considers only pure geometrical features (curve-based planning) without relation to the real robots. The second concept conversely takes into account the dynamical features of the real robot with initial and final points (point-to-point planning).