DSP-based self-tuning IP speed controller for rolling mill DC drive

This paper describes the design and the implementation of a self-tuning integral-proportional(IP) speed controller for a rolling mill DC drive system, based on a 32 bit floating point Digital Signal Processor TMS 320C30. To get a better transient response than conventional proportional-integral(PI) and/or integral-proportional (IP) speed control, an adaptive self-tuning IP speed control with load torque feedforward compensation was used in the presence of transient disturbance and/or parameter variations. The model parameters, related to motor and load inertia and damping coefficient, were estimated on-line by using a recursive extended least squares (RELS) estimation algorithm. On the basis of the estimated model parameters and a pole-placement design, a control signal was calculated. Digital simulation and experimental results showed that the proposed controller possesses excellent adaptation capability under parameter change and better transient recovery characteristic than conventional PI/IP controller under load change