Abstract:

This paper presents an experimental educational platform enabling undergraduate and graduate engineering students to practice real-world identification and control of a DC servomotor through a Programmable Logic Controller (PLC) with analog interfaces. The servomotor is first described by a continuous-time second-order model encompassing both electrical and mechanical dynamics; however, for controller design and identification purposes, it is simplified to a first-order approximation based on dominant mechanical behavior. Discrete-time algorithms are employed, requiring the model to be discretized. Parameter estimation is conducted using the Recursive Least Squares (RLS) algorithm, and speed control is achieved via the Pole Placement method utilizing the Reference Signal Tracking (RST) framework, both programmed in Structured Control Language (SCL) on the PLC. This approach allows students to bridge simulation and industrial experimentation, making it highly suitable for courses such as Automatic Control and Applied Automation, and enhancing practical understanding of advanced control techniques with standard laboratory equipment.

Keywords:

DC servomotor, parameter identification (RLS), poles placement (RST), SCL programming language (PLC), didactic application.