FACTFILE: Segway HT i180

The Segway is a two-wheeled motorised platform that operates by electricity, being charged up from a normal wall outlet.
      All elements of the device contain 100% redundancy, in that all working parts - computers, motors, etc. - are duplicated, in order to ensure that a single failure will not cause the device to fall over (see below) or break down.
      The key feature of the Segway is that it is self-balancing, thanks to what is described as "dynamic stabilisation". In other words, an array of gyroscopes, tilt sensors, microprocessors, and electric motors keep it balanced, mimicking the actions of the human inner ear, the eyes, muscles and brain. The technology is concentrated in the robotic platform between the wheels, on which the user stands.
      It is generally considered impossible to fall off a Segway, although President George W. Bush has famously disproved this theory.
     
The vehicle moves forward when the user leans forward, and goes into reverse when one leans back. Braking in either direction takes place simply by adjusting the body position. There is a set of handlebars with a steering grip for turning, but no "throttle", "brake" or "gears" as such - the body position determines the direction (forwards or backwards) and the speed, up to a maximum of around 20km/hour.
      The height of the control shaft and handlebars can be adjusted to fit all sizes of rider and allow for easier storage.
     
There are a number of alternative versions available, at least in the U.S. market: the basic i180 is accompanied by an all-terrain model (the XT), a golfer's model with a golf bag carrier (the GT), and the smaller, lighter p133 model.
      The patented device is the brainchild of American physicist Dean Kamen.
      The name "Segway" is a play on words from "segue" - a smooth, seamless transition.
     
     
SPECIFICATIONS
     
Maximum speed : 20km/hour (12mph) see also below
     
Propulsion: 2 brushless DC servo motors
     
Weight: c. 38 kg (84 lbs)
     
Payload (passenger and cargo, max.): 118kg (260lbs)
     
User weight: min. 45kg (up to 110 kg; 100-250 lbs)
     
Platform height: 21 cm (8 inches)
     
Energy source: 2 x rechargable Lithium-ion or NiMH batteries
     
Charge duration: approx. 6 hours; lifetime of around 300-500 charge/discharge cycles
     
Range: 15-20 km/charge. Range varies with terrain and battery type; Li-ion batteries give longer range but have longer recharging times.
     
Footprint: 48 x 63 cm (19 x 25 inches)
     
Three colour-coded ignition keys can control the top speed and turning response: Beginnner (black) up to 9.6 km/h or 6mph; Intermediate (yellow) up to 13 km/h or 8 mph with a more responsive steering action, and Advanced (red) up to the maximum speed of 20km/h, with the most responsive steering action. The Segway can turn on its own axis, balancing on a single axle, while stationary.
     
Recommended retail price in Finland : EUR 4,950 (Segway i180); EUR 4,350 (Segway p133); EUR 5,550 (Segway XT); EUR 5,950 (Segway GT).
     
Helsingin Sanomat / Adapted from an article first published in print 6.8.2005

More on this subject:
 The Segway HT comes to Finland - as an outlaw

Links:
  Bush fails the Segway test (BBC)
  Segway official site: models and specifications