The Segway Personal Transporter
The Segway personal transporter is a two-wheeled, self-balanced electrical vehicle produced by Segway, Inc. Computers and motors in the base of the device keep the Segway upright, and the user steers the vehicle by simply leaning in the direction she wants to go. Gyroscopic sensors are used to detect the tilting of the device (which indicates departure from perfect balance) and motors driving the wheels are commanded as needed to bring the vehicle back into balance. If you have never seen a Segway in action, please take your time to watch the promotional video clip below.
In this tutorial, we are going to build and control a Segway-like vehicle in LEGO Mindstorms. We will show how control theory can be used to develop simple and powerful strategies for maintaining the vehicle in balance. We will not dive into the theory in its fullest generality, but simply combine things you already know from high school physics and math. This will allow us to build a model of the vehicle dynamics and find out how the motors should be controlled to maintain balance. In doing so, we will reinvent the so-called “PD-controller” and use it to transform measurements of the tilt angle into the appropriate acceleration that should be supplied by the motors. We will discuss various way of measuring the tilt angle of the device, and show how the proposed controller can be implemented in the LEGO Mindstorm hardware.
Afte the tutorial, we hope that you will have a basic insight into the use of control theory and that you will feel ready to make your Segway clone more than balance - to move and win the Segway challenge! [continue »].