A procedure to evaluate Extended Computed Torque Control configurations in the Stewart–Gough platform

Parallel robots have become the best solution when high speed and/or accuracy are needed in industrial robotic operations. However, in order to meet the requirements of these tasks, advanced model based controllers such as the Extended CTC scheme are required. This CTC-based scheme requires the introduction of extra sensors in the passive joints of the parallel robot. This redundant information allows to increase the robustness and performance of the control law, leading to better trajectory tracking. However, in order to achieve the best performance, a proper extra sensor distribution is required. In this paper, a sensitivity analysis based approach is applied to the well known Gough Platform in order to evaluate different extra sensor distributions. The obtained results are compared with those obtained by a statistically significant set of simulations, demonstrating the effectiveness of the methodology.

► The use of extra sensors in Parallel Robots can improve trajectory tracking in CTC based approaches.
► We propose a sensitivity based analysis to detect the most suitable extra sensor disposition.
► The main advantage of the approach is its low computational cost.
► The procedure is validated in a Gough–Stewart platform by comparison with a statistical analysis.