Implementing digital controllers: a case study

Describes a laboratory experiment that provides students in a digital control course the opportunity to implement their digital controllers on a PC with data acquisition board. Before implementing their controllers, students are exposed to some of the practical issues that arise in practice, such as analog/digital conversion, quantization error, and sampling effects. In the lab, they are asked to model a second-order electro-mechanical system, design a digital PID controller based on the model, and write C code to implement their controller. In this way, students learn to program real-time digital control actions using timer-based interrupts implemented in C. Thus, they obtain a hands-on demonstration of digital control in action.