Specifications

Page 54 of 106 Basic Rider Optimization Training for the Segway HT

Instructor Guide and Participant Workbook Rev 3.5i - January 2004

Attempting to exceed the speed limit results in two undesirable outcomes:

> Posture that is detrimental to safe riding Since the Handlebar is pressed into your torso, your

arms and legs are not in an appropriate position. Your legs will generally straighten, as you lean

back on your heels due to the aft tilt of the Platform. You will have a difficult time correcting in

case of any changes in the terrain, or in your speed.

> Reduction in range, because of the constant acceleration/deceleration taking place

Motor Saturation

An electric motor produces torque. The faster it goes, the less torque it can produce. At some point,

the motor “saturates” which means even if more torque is commanded, more torque is not produced.

This is equivalent to “flooring it” in a car. In the HT, the available torque and speed (the “reserve”)

depend on:

For any dynamically stabilized machine, it is important to know where this saturation limit is so that

the Segway HT can: (a) keep the operator away from this operating point, if possible or (b) warn the

operator if they approach this operating point

The HT endeavors to keep the operator away from this limit by limiting speed. The term “reserve”

is used to describe the torque and speed buffer between the current operating point and the

capabilities of the drive system. This works when the Segway HT is moving as opposed to

stationary.

The Display indicates that the Segway HT is reducing performance

deliberately by showing a straight-faced icon. The appropriate rider

response is to slow down. Do not try to lean past the speed limit, which

has been lowered until the condition ceases to exist.

Guide each participant to a Segway HT.

> Start the Segway HT with the Beginner Key (6mph).

> Ask the participants to watch you demonstrate speed limiter.

> Tell them to pay close attention to the Handlebar, the Platform, and your posture.

> Exceed the speed limit for a few seconds so they can see the effects.

One way for the Segway HT to limit speed is to adjust the pitch of the Platform. By tilting the Platform

backward, the Segway HT can inhibit forward acceleration by making it difficult for the rider to get

his/her center of gravity in front of the contact patch. The Speed Limiter looks at the speed limit and

the actual speed and, if the speed is greater than the speed limit, the Segway HT begins to pitch

backward. Persistent operation over the speed limit causes this offset angle to increase.