The Segway PT is a two-wheeled self-balancing battery-powered electric vehicle invented by Dean Kamen. It is produced by Segway Inc. of New Hampshire, USA. The name Segway is a homophone of the word segue, meaning "smooth transition"; PT denotes "personal transporter".
Computers and motors in the base of the device keep the Segway PT upright when powered on with balancing enabled. A user commands the Segway to go forward by shifting their weight forward on the platform, and backward by shifting their weight backward. The Segway detects, as it balances, the change in its center of mass, and first establishes and then maintains a corresponding speed, forward or backward. Gyroscopic sensors and fluid-based leveling sensors are used to detect the shift of weight. To turn, the user presses the handlebar to the left or the right.
Segway PTs are driven by electric motors and can go up to 12.5 miles per hour (20.1 km/h).
Read more about Segway PT: Early History and Pre-release Marketing, Technology, Uses