Understanding the Basics of the Model-Based Techniques for Control Engineers with Simulink and BeagleBone Black: Processor-in-the-Loop Simulation of a DC Motor Speed Control

Model-based design and testing incorporate computer models of dynamic systems in the workflow to reduce the development or testing time. These techniques are widely used in a control engineering practice as a step beyond the strictly computer simulation and as a method to combine computer models and physical equipment. Processor-in-the-loop (PiL) is one of the tests involved in a model-based approach that allows to combine the computer simulation (computations performed on a computer) and the microprocessor simulation (partially, computations are performed as a microprocessor program). The simple model of a DC motor speed control with a discrete representation of the DC motor has been used to develop a basic hybrid model. Simulink Embedded Coder has been used to generate the code for the implementation at the BeagleBone Black platform. Afterwards, the model ran in the external mode in two cases, where the code running on a hardware platform simulated (i) PI controller (a `traditional' PiL technique) and (ii) DC motor (thus introducing the simplified understanding of other model-based techniques). The platform and the model are recommended as a basic tool to demonstrate the interaction between the computer model and hardware for control engineers.