Improved tracking control of industrial servo-drive system by saw torque feedback

This paper provides a comparative, systematic analysis of conventional and non-conventional velocity control algorithms for a two-inertia mechanical system. The assessment criterion is based on the integral of time multiplied by absolute error performance index, normalized as a function of the mechanical parameters, allowing a direct comparison between simple proportional-integral and more complex control schemes. Tuning methods for extended control structures are presented and performances evaluated using the dynamics of a commonly employed proportionalintegral controller as a benchmark for assessment. It has been shown that the required controller complexity to provide good performance is directly related the mechanical system parameters and is most critical when the load inertia is smaller than that of the motor. Extended structures incorporating a torque feedback signal derived from a low cost, surface acoustic wave transducer are presented and shown to significantly improve the tracking performance of the classical proportional-integral controller.