A study on feedforward Tracking Control for XY table by real-time experiments

The common approach in feedforward control for a servo system which normally presented by non-minimum phase model is Zero Phase Error Tracking Control (ZPETC). This technique can solve the problem of unstable zeros of the plant model. Using the same technique, there are various extended algorithm have been proposed. In this paper, three techniques of feedforward ZPETC are considered to compare their performance by real time experiment of an XY table. The control techniques used for the comparison are the conventional ZPETC by factorization of zeros, error filter ZPETC and Adaptive ZPETC without factorization of zeros. The comparisons are based on the tracking error, contour error and the error at the sharp angles. The mathematical model of the XY table is acquired by System Identification technique using Matlab toolbox. The experiments were done using high frequency input. The tracking performances of the controllers are compared based on their contour error.