Safety In Design
A tradition of Segway Inc. is designing, while keeping safety in mind, products that are simple, elegant, and efficient. In this section we talk about the redundant subsystems that were designed into the Segway PT since the invention of the product as well as the design of the recently released Segway Modular Parking Stand accessory...also designed with safety in mind.
The Segway PT has been designed to self diagnose system faults. If the Segway PT detects a fault in any of its redundant systems, the machine will automatically warn you with a beep, reduce its speed, give the Stick Shake warning (shakes the handlebar and makes growling noises), flash the Balance Indicator lights, and the InfoKey™ Controller displays an unhappy face. You have 10 seconds from the start of the safety shutdown to come to a controlled stop and carefully step off one foot at a time. DO NOT GET BACK ON THE SEGWAY PT AFTER A SAFETY SHUTDOWN, until the condition that caused the Safety Shutdown has been identified and corrected. (The Safety Video has a demonstration of a Safety Shutdown)
Safety Redundant Subsystems
The Segway PT has been designed with concern for the safety of the rider and those who may be nearby. Redundant subsystems maintain controlled operation of the Segway PT in the unlikely event of a component failure. If one component in a subsystem fails, the other component continues to operate, allowing you to come to a complete and safe stop before stepping off by triggering a safety shutdown.
The Segway PT Redundant Subsystems:
Controller Boards; The Brains of the Machine
The two Controller Boards receive input from the gyroscopes and other sensors. The Controller Boards also monitor battery condition, send commands to the motors and are interchangeable. They are connected to the Control Shaft Cords, the Balance Sensor Assembly, the Batteries, and the Motors, so that if there is a malfunction in any of these components or the connections between them, the Segway PT will perform a Safety Shutdown.
Motors With No Pollution Emissions
Each wheel is independently driven by redundant, high-speed electric Motors that produce no pollution emissions and have been tested to power levels of two horsepower. The brushless design employs computer technology to precisely regulate motion. Each Motor is wound as two separate electrical circuits, capable of independent operation, acting as one mechanical entity. The Motor for each wheel (right/left) is connected to the front and rear drive systems. This allows either the front or the rear drive system to produce torque on the Motor shaft. The system uses independent controllers for the front and rear drive systems. If either Motor fails, the Segway PT will perform a Safety Shutdown.
Two Li-ion Batteries
The Segway PT (generation II) Segway PT uses two Lithium-ion Battery Packs that are sealed units in the base requiring no maintenance besides proper charging and storage. One Li-ion Battery Pack is installed in both the front and back of the Segway PT base. The batteries are interchangeable front/rear, however the same chemistry needs to be installed on both the front and rear of the platform, if a fault is detected in either Battery Pack, the Segway PT will perform a Safety Shutdown.
Balance Sensor Assembly
The Balance Sensor Assembly contains five angular rate sensors (solid state gyroscopes) and two tilt sensors. These sensors gather information about the orientation of the platform in all three planes (pitch, roll, and yaw) and sends it to the controller boards. All five rate sensors constantly check each other to ensure each is operating correctly. The two tilt sensors do the same, and if any fail, the Segway PT will perform a safety shutdown.
Segway Modular Parking Stand
You'll have to step off the Segway PT at some point. When you do, reach level ground, step down from the sSegway PT, turn off the Segway PT and with just a quick tap of your foot, deploy the parking stand and you'll be parked and ready to go about your business. The sleek and simple design pivots up 180 degrees left or right and locks in place for when you're ready to glide again.
The parking stand was designed with safety in mind and therefore, there is a mechanical fuse built into the leg to allow for breakage in the event of misuse of the accessory. Misuse of the accessory could be, but is not limited to, attempting to step on a PT with the parking stand deployed, failure to fully stow the parking stand prior to riding or inadvertent deployment while riding.
If the leg breaks, it is easy to replace and can be installed with just one screw. We provide a spare leg and fastener with every kit. If you run out of replacement legs, you can now purchase spares separately.
The Modular Parking Stand is available for both i2 and x2.
Online ordering will be available soon. In the meantime, contact your local dealer.
A Note From Our Engineers:
The Segway PT Parking Stand was designed at Segway Inc., in the Segway tradition of designing simple, elegant, and efficient products.
The Segway PT parking stand is easy to install on the front of the machine with just two mounting bolts supplied with the accessory kit.
The Segway PT parking stand was designed with safety in mind and therefore there is a mechanical fuse built into the leg to allow for breakage in the event of misuse of the accessory. We used cast aluminum to take advantage of the material properties for the mechanical fuse.
This mechanical fuse is a safety feature to protect the rider in the event of inadvertent contact between the ground and the leg of the parking stand. If this happens, the leg will break away protecting the rider from a 3rd point of contact with the ground.
To minimize breakage, the user should make sure the parking stand leg is fully stowed prior to use and the rider should never attempt to step on a machine with the parking stand deployed. The user should also retract the parking stand prior to moving the un-powered Segway PT from place to place as dragging the leg along the floor or ground may be sufficient to cause the mechanical fuse to break.
In the event of a breakage, the leg is a simple to replace item and can be installed with just one screw. The tools for this replacement are supplied with the accessory and spare legs are also available to purchase.
User instructions are provided with every parking stand and we recommend reviewing all instructions before installing and using the parking stand. You can also Download the full user materials for the Modular Parking Stand here.