I’ve spent the last eight years focused on the art of engineering education, and have found that in many cases, a simple physical demonstration or interactive project can make a huge difference when trying to explain difficult concepts. The following are a couple examples of projects I’ve created to better help students understand the principles of engineering.
In order to better teach the basic principles of PID (proportional, integral & derivative) control theory as it relates to factory automation, I’ve created and refined a small demonstration inverted pendulum.
The hardware includes a linear slide with a small DC servo motor and attached incremental encoder. There’s a second encoder on the hinge that connects the pendulum to the slide. That hinge is very low friction; any friction at that joint causes major control issues! An Arduino mega with a motor shield is driving the system — the mega was required to enable real-time reading of signals from both encoders, using the interrupt pins on the Arduino (two interrupts per encoder).
The Arduino code is based on another project. I modified the code quite a bit, allowing easy software switching between P, PI and PID, and also enabling simultaneous display of the target and actual angular position of the pendulum, which helps to illustrate overshoot, settling time and steady-state error.
There are two PID control loops: the outer loop aims to keep the cart position on the slide in the center; the controller output is the target pivot angle for the inner loop If the cart moves right, the target angle tilts left to cause the cart to move back to center The inner loop just aims to keep the pendulum vertical by moving the car to get the actual pivot angle to match the target angle.
For a course on computer aided-design and machine components, in which students learn about gears and gear trains, I created a project where each student purchases and disassembles a battery-powered screwdriver and is asked to model, draw, and analyze the gearbox inside, and create a report in the form of a design portfolio entry. For many students, this is the first time they have been asked to take something apart and figure out how it works, and it allows them to see how machine components and design for manufacturing principles are applied in a product. It’s clear that in combination with theory and analytical tools, this kind of experiential learning is critical for giving students a complete picture and deeper understanding of how engineered artifacts are made.