Model based control of a high precision dual gantry platform with elastic cross coupling

摘要

In many cases handling processes rely on precise and fast pick-and-place operations. This may be achieved by means of so-called H-gantry systems. In order to increase the throughput of such devices they are often extended by a second, asynchronously working gantry. Due to the finite stiffness of the mounting base of the linear motors and vibrations of the base frame an interaction of both gantries can be observed. The contribution proposes a flatness based approach to compensate for this effect. This approach is based on a simplified quasi-stationary model of the base frame and relies on the parameterization of the system trajectories by a so-called flat output. This allows on the one hand for a significant decrease of the base frame vibrations and, thus, for a better performance of the position control. On the other hand a more precise compensation of the coupling effect can be achieved compared to standard trapezoid acceleration trajectories. Simulation studies and experimental results show the efficiency of the proposed algorithms.