Feed velocity based coordinated contouring control for dual-linear-motor-driven gantry stage via fully actuated system approach

Contouring control of the dual-linear-motor-driven gantry system (DLMDGS) is critical in industrial research, as it significantly affects the performance of motion equipment. However, present results cannot fully exploit the fully actuated characteristic of the DLMDGS, and their implementation complexity limits practical applications. To circumvent these limitations, the paper proposes a control scheme based on the fully actuated system (FAS) approach within a global task coordinate frame, ensuring high-precision contour tracking through multi-axis coordination and redundant actuator synchronization. Integrated with a fixed-time disturbance observer, the FAS control scheme effectively deals with system uncertainties, disturbances, and nonlinearities, resulting in a desired closed-loop structure. Compared with the conventional methods that rely on numerically estimated path length, the FAS controller is designed based on the desired contouring velocity, thereby avoiding errors introduced by numerical estimation. Moreover, the fixed-time convergence of the disturbance observer and the stability of the proposed control scheme are theoretically proven. Finally, the effectiveness of the proposed FAS control scheme is validated by experiments on a real DLMDGS platform.