earticle

영어

The focus of this paper is on the development and high precision robust control of an electro-mechanical robot manipulator that serves as a sensing and motion system for hybrid testing. The originality of the design is inspired from the Stewart Platform mechanism for a parallel axis configuration and a two-degree-of-freedom (2-DoF) moving platform. This design resulted in strongly non-linear and coupled dynamics as well as an inertial moving platform that attracted model-based control strategies. A novel non-linear control technique based on differential-geometric flatness was selected to meet the multiple simultaneous specification control of linearization, decoupling and asymptotic tracking. Pole placement was used to achieve a stable tracking, while the fuzzy-logic added intelligence to the control system through an automatic tuning of the pole placement coefficients. Simulation results demonstrated the validity of the fuzzy-flatness control with asymptotic and stable tracking at different frequency inputs. For the experimental implementation, the real-time constraint was further imposed and the actuators time-delay was compensated for using a forward prediction algorithm based on a fourth-order polynomial extrapolation. This compensation demonstrated a well synchronized control signal at different excitation conditions. Moreover, the non-linear flatness control was systematically assessed for the experimental validation and its implementation was made accessible for future validation and perspectives. This current research has contributed to the rapprochement of three important autonomous domains, namely: Parallel Manipulators, Hybrid Testing and Automatic Control. In addition, it has inspired many research perspectives for robust non-linear control and multi-frequency substructuring.