A novel undergraduate learning tool for engineering control and applied rheology

Meaningful engineering projects involve systems engineering which challenge students to apply knowledge they gained in studying individual subject-centered courses into a holistic product. This particularly applies to engineering students who are traditionally applications oriented. Engineering controls is a course most students find challenging to master in the limited time at their disposal within traditionally crowded engineering syllabus. However, presenting them with a singular and palpable task which requires application of this basic knowledge" and even more, lends itself to learning through self-discovery. This is particularly the case in mechatronics, robotics and automation in general" a backbone to most of devices in use today, where the control theory plays a crucial part. Engineering rheology is a specialist branch of Fluid Mechanics encountered by only a few students" usually at the postgraduate level. It deals with the behaviour of fluids often outside their every-day experience, and which is often contrary to the expectations. It is therefore a special challenge to undergraduate students who are only used to the behaviour of Newtonian fluids they had studied (and experienced) hitherto, to at least obtain a working knowledge of the esoteric subject in order to own up to the posed problem they chose to tackle. It too requires learning through self-discovery. The aim of this paper is to describe one such project undertaken by final year students under the authors' supervision and guidance. It involved application of control algorithms to a fluid whose rheological properties varied with the applied load through a specialised feedback loop controlling the magnetic field strength to which the fluid was exposed. The fluid viscosity varied with the strength of the applied magnetic field." which imparted to it the non- Newtonian characteristics. Such fluids are called magneto-rheological fluids or more commonly, just MRFs. The mechanical component using an MRF was a damper such as used in automobiles. However, rather than the commonly used "passive" variety, an MRF damper is an "active" one" damping varied with the frequency of the applied load.