A Methodology to Teach Students to Implement Digital Controllers Using Embedded Systems

A Microcontroller Based System for Improving the Learning Process of Undergraduate Students in the Control Systems AreaMost of the course projects in the Control Systems Area are implemented using high levelsimulation tools and data acquisition boards. This method has yielded excellent results; but it hasthe disadvantage of not exposing students to implementing digital controllers directly withmicroprocessors. This issue is common to many universities. In this paper we propose a solutionthat will improve student’s understanding on how digital control systems are implemented in thereal world.Previous work has shown that using Simulink versus using microcontrollers yield similarperformance of digital controllers implemented in the Digital Control Systems Course Projects.Other authors have used a low-cost microcontroller system to perform real-time feedback controlexperiments. Specifically, their system was tested with undergraduate students by providing themsome code examples and a sample project. Results showed that students improved theirunderstanding on how control systems work.The proposed system uses the Texas Instruments C2000 F28069 Microcontroller, the DRV8833motor driver, and a custom made Analog Signal Conditioning Board. The system is enclosed in abox with all the ports needed to connect to the Controls Laboratory Experiments. A set of Clanguage libraries with solutions to the most common control problems is being developed.The effectiveness of this approach, compared to other methods (Simulink, Labview, etc.), isbeing tested with a pedagogical experiment that follows a backward design approach, in whichthe content, assessment, and pedagogy used to implement the proposed system are aligned. Inthis study, the content refers to a desired student outcome of the Digital Control Systems courseaccording to the existing ABET criteria: implement a digital controller using a digital computerand software (outcome e). The pedagogical activities include various workshops for a group ofstudents currently enrolled in the course. These are designed to enhance the implementation ofthe digital control system in the course project.A total of 3 workshops, of 2 hours each, will be given to students. It is expected for students touse their design and problem solving skills to implement the digital control system with themicrocontroller. In the first workshop, an overview of the Microcontroller Based Control System(MCS) is presented. In the second workshop, the students will learn how to read signals fromsensors and how to write a PWM output signal to the motor driver. In the third workshop, theywill use those signals to design and implement a basic proportional controller for the SRV-02servomechanism.Various instruments for data collection will be used. For instance, pre-and post-test are beingdesigned for each workshop to measure student outcomes. Student’s designs that result from eachworkshop will be assessed and graded following a pre-established rubric. Finally, the professorwill evaluate student’s performance through oral presentations using a rubric that has beendesigned to measure student outcomes as established by ABET criteria.