Teaching classical controls systems design to mechanical engineering students presents unique challenges. While most mechanical engineering programs prepare students to be well-versed in the application of physical principles and modeling aspects of physical systems, implementation of closed loop control and system-level analysis is lagging. It is not uncommon that students report difficulty in conceptualizing even common controls systems terms such as steady-state error and disturbance rejection. Typically, most courses focus on the theoretical analysis and modeling, but students are left asking the questions…How do I implement a phase-lead compensator? …What is a non-minimum phase system? This paper presents an innovative approach in teaching control systems design course based on the use of a low-cost apparatus that has the ability to directly communicate with MATLAB and its Simulink toolbox, allowing students to drag-and-drop controllers and immediately test their effect on the response of the physical plant. The setup consists of a DC micro-motor driving a propeller attached to a carbon-fiber rod. The angular displacement of the rod is measured with an analog potentiometer, which acts as the pivot point for the carbon fiber rod. The miniature circuit board is powered by the USB port of a laptop and communicates to the host computer using the a virtual COM port. MATLAB/Simulink communicates to the board using its serial port read/write blocks to command the motor and detect the deflection angle. This presentation describes a typical semester-long experimental protocol facilitated by the low-cost kit. The kit allows demonstration of classical PID, phase lead and lag controllers, as well as non-linear feedback linearization techniques. Comparison between student gains before and after the introduction of the mechatronic kits are also provided.
Wet spinning of low cost carbon fiber precursor-lignin incorporated polyacrylonitrile co-polymer fiber