Aero-stabilizer workbenches for the teaching of PID control

Abstract

Teaching Engineering students some theoretical concepts of Control Theory is quite a challenge. Practical and theoretical skills must be taught in parallel because those students are being prepared for working at industry, developing added value for the economy of the country where they belong. In Portugal, the domain of Control and Automation is quite important due to the fact that economy grows based on knowledge and development of high added value products. These ideas are being invoked by government institutions and accepted by industry and universities. So, this work has been developed on the context of Triple Helix of university-industry-government relationships. Hand-on experiments related to those concepts may be a significant help. This paper presents two aero-stabilizer workbenches that were designed in order to help the teaching of Proportional–Integral–Derivative (PID) controllers. Each workbench has a bar which is free to rotate about one of its extremities. A motor propeller assembly at the other end of the bar raises it. The desired bar orientation is obtained by controlling the rotation speed of the motor. Bar orientation is measured with an optical encoder that sends a feedback signal to a PID controller. The two workbenches differ only on the electronic system that performs the PID control. One of them uses an industrial Programmable Logic Controller (PLC) for that purpose. The other uses an Arduino platform. Having both workbenches will allow students to work with two widely used microcontroller technologies and to compare them. Some fundamental concepts and the main components required to build the workbenches are described.