An adaptive controller for a smooth positioning system: analysis and simulation

The authors describe the implementation of a self-tuning regulator for the positioning of a direct-drive servo motor. The servo motor is a permanent magnet DC motor in which no gear reducer is used. The autotuning regulator consists of two major loops. The inner loop contains a feedback (proportional-derivative or proportional-integral-derivative) regulator with additional feedforward terms. The parameters of the regulator are adjusted by the outer loop, which contains an online parameter estimator. The estimated parameters are the load inertia and friction. This self-tuning regulator has been simulated with PC.MATLAB, and the results demonstrate the high performance of the scheme. The influence on the estimator of important factors such as noise, forgetting factor, and converter precision are evaluated