A Novel Adaptive Jerk Control With Application to Large Workspace Tracking on a Flexure-Linked Dual-Drive Gantry

In this work, the design of a novel the flexure-linked dual-drive H-gantry is first introduced. Compared to conventional stacked X-Y tables, the advantages of this gantry are on decoupled X-Y actuation, better mechanical reliability, larger driving force, and shorter response time. However, after deriving its reduced-order dynamical model, it is found that the precision of the end-effector is significantly affected by the position dependent torque caused by the inter-parallel-axes driving forces on the fixed inertia frame and coupling forces from the pair of flexures. These form barriers that limit precision positioning and tracking performance over a large workspace. Thus, in the following part, a robust integral of signum of error (RISE) control with novel jerk adaptation is proposed on top of the standard proportional-integral-derivative (PID) and feedforward scheme. Compared with some prior RISE schemes with gain adaptation, the proposed scheme yields bounded robust gain in the presence of noisy velocity estimation. Real-time experiments on the actual testbed indicate that both improvement of motion precision and prevention of resonant mode excitation over a large workspace are successfully achieved in the proposed scheme.