MotoShield: Open Miniaturized DC Motor Hardware Prototype for Control Education

This article introduces a prototype reference design for the classical motor speed tracking experiment that is extensively used to teach control engineering and mechatronics concepts all over the globe. The literature is abundant with similar experimental setups combining a direct current motor and an incremental encoder, with the aim of controlling the rotational speed using feedback methods. The didactic device proposed here is special in that it integrates this setup into a miniaturized package at a very low cost, effectively creating take-home experimental systems suitable for remote teaching. In our concept, the motor-encoder coupled with power and measurement electronics is tightly integrated in a so-called shield, which is compatible with a range of microcontroller prototyping boards from the Arduino ecosystem and third-party compatibles. The hardware reference design is offered as an open-source, community driven initiative. In addition to the proposed device we present an application programming interface to abstract fundamental hardware functions and aid the education of higher concepts in control, system identification, signal processing or mechatronics. The programming interface is available in C/C++ for the Arduino IDE, in the MATLAB scripting language and as a Simulink blockset. Demonstration examples for feedback control and system identification are also provided for each environment. The combination of the open-source hardware and programming interface creates a powerful concept that is founded on standardization, meaning that educators may collaborate not only in bettering the existing hardware and software, but also on creating common teaching materials.