Silly Questions!

It has been a while snce I had put up anything on my blog again :-( I guess we've been too busy with other things that kept us off-line for a while. Anyway, we're back and we've got 'stuff' to blog about! :-)

While out at Johsonville one afternoon, someone approached me; after asking about FrankenSeg and the technology behind Segways, he asked 'what is the silliest question you've every been asked?' And to be honest, the silliest one I've ever had, well, actually, I got it a few times, is 'what is wrong with walking?' It really puzzles me! To be honest, there is 'nothing wrong with walking! Or least as far as I know, maybe someone somewhere knows something I don't about walking! :-)

Another question that gets asked is: “is it true that you can't fall off a Segway?” That, of course, depends on how much you 'want' to fall off! Of course you can fall off a Segway and there are dozens of examples of people doing just that! More often than not they are deliberately putting themselves in danger by doing, what I consider to be, silly and moronic things. To be fair there are also clips of people actually getting into real accidents and falling off. But like a car or a bicycle, you can crash or fall off if you try hard enough! Try it if you don't believe me! :-)

The most difficult question to answer, maybe only because I am a 'tech' at heart and like my 'hard-data', is 'how far can you go?' The short answer is roughly 24km on a full charge around the Wellington area. I feel it is import to specify that because of the unique environment we have here, we have lots of hills! For example, when I go into the Wellington Central Business District, which is about 12.4 km from where I live, it'll 'cost' 2 battery bars to go that distance. However, the way home, same route, except that it is up hill will cost around 6 battey bars. And just to add to the fun, there are days when it 'costs' even less to get home when there is a good tail wind! Like in strong enough to push you and the Segway uphill fast enough of the speed limiter to kick in.

Not with-standing there are the questions as to “how is easy is it to learn?”, “where it can go” , “how steep a hill” and “how does it handle 'off-road'?” These of course, have all been answered here in this blog at some point in time, now in the past or in the future.

In general, people are curious about the technology that makes the Segway 'go'. I always make the time to stop, answer questions or explain how it all works. Others have even thanked me for allowing/letting them see a Segway 'in real life'.

Segway Regulatory Information

In New Zealand owners operate their Segway PT as a Mobility Device, the same category as a mobility scooter or electric wheelchair. Mobility Devices must be operated on footpaths whenever they exist and are reasonably accessible, otherwise along the side of the road with traffic (in which case road rules must be obeyed). On footpaths, operators must ride at a speed that does not endanger others, and give way to pedestrians.

How it Works - Segway Smart Motion™ - The science behind the technology

When Dean Kamen unveiled the Segway® Personal Transporter (PT) on ABC's Good Morning America, he described the machine as "the world's first self-balancing human transporter." When you look at the machine in motion, you get an idea of what he's talking about. Unlike a car, the Segway PT only has two wheels, yet it manages to stay upright by itself.

To move forward or backward on the Segway PT, the rider just leans slightly forward or backward. To turn left or right, the rider simply moves the LeanSteer frame left or right.

HOW DYNAMIC STABILIZATION WORKS
The ability to balance on its own is the most amazing thing about the Segway PT, and it is the key to its operation. To understand how this system works, it helps to consider Kamen's model for the device—the human body.

If you stand up and lean forward so that you are out of balance, you probably won't fall on your face. Your brain knows you are out of balance, because fluid in your inner ear shifts, so it triggers you to put your leg forward and stop the fall. If you keep leaning forward, your brain will keep putting your legs forward to keep you upright. Instead of falling, you walk forward, one step at a time.

The Segway PT does pretty much the same thing, except it has wheels instead of legs, a motor instead of muscles, a collection of microprocessors instead of a brain and a set of sophisticated tilt sensors and gyroscopic sensors instead of an inner-ear balancing system. Like your brain, the Segway PT knows when you are leaning forward. To maintain balance, it turns the wheels at just the right speed, so you move forward. Segway calls this behavior dynamic stabilization and has patented the unique process that allows the Segway PT to balance on just two wheels.

THE BRAINS AND THE BRAWN
The Segway PT is controlled by an intelligent network of sensors, mechanical assemblies, propulsion, and control systems. The second you step on, five micro-machined gyroscopic sensors and two accelerometers sense the changing terrain and your body position at 100 times per second – faster than the brain can think.

Segway PTs use a special solid-state angular rate sensor constructed using silicon. This type of gyroscopic sensor determines an object's rotation using the Coriolis effect on a very small scale.

Simply put, the Coriolis effect is the apparent turning of a moving object in relation to another rotating object. For example, an airplane trying to travel in a straight line can appear to turn because the Earth is rotating underneath it.

The Segway PT has five gyroscopic sensors, though it only needs three to detect leaning forward or backward (termed “pitch”), leaning to the left or right (termed "roll") and steering to the left or right (termed “yaw”). The extra sensors add redundancy, to make the product more reliable. All of this leaning and steering information, as well as information from additional tilt sensors, is passed on to the brain of the device.

The brains and brawn are made up of two identical and redundant sets of microprocessor-based electronic controller circuit boards, batteries and motor windings that operate together and share the load of driving the wheels. The Segway PT has a number of additional onboard microprocessors. The vehicle requires this much brain power because it needs to quickly make precise adjustments to keep from falling over. If one controller board (or it’s associated battery, motor windings or wiring) breaks down, the other set will take over all functions so that the system can notify the rider of a failure and shut down gracefully.

The microprocessors run an advanced piece of software that controls the Segway PT. This program monitors all of the stability information coming from the gyroscopic sensors and adjusts the speed of the electric motors in response to this information. The electric motors, which are powered by a pair of rechargeable lithium-ion batteries, can turn each of the wheels independently at variable speeds.

When the PT leans forward, the motors drive both wheels forward to keep the PT from tilting over. When the PT leans backward, the motors drive both wheels backward. When the rider moves the LeanSteer frame to turn left or right, the motors drive one wheel faster than the other, or if traveling slowly enough, drive the wheels in opposite directions, so that the Segway PT rotates (steers). When under way, the Segway PT will generate precisely the right radius of turn so that your lean is balanced by the centripetal acceleration generated by the turn.

Segway i2 Platform Exposed

Here is a cut away view of the Segway i2 platform, the electronic brain of the machine.

<>

Single Wheeled Version of The Segway

No to be out done, an Slovenian inventor Aleksander Polutnik, has come up with the Enicycle - a single wheeled Segway. And very much like the Segway it relies on multiple gyroscopes and a computer to balance (makes 100 adjustments every minute) as well as the lean forward/backward for movement. Steering, on the other hand, is hands-free and relies on the rider to 'push' the foot rests in the appropriate direction - similar to how the lean steer works in the i2 and x2 Segway models.

The current prototype has the following specifications:
- 15 km/h max speed
- 30 km range on a single charge
- 5 hours recharge time
- and weighs 28 kg

But will it surpass the Segway? At the moment there have been only 2 made so far, initially designed so that the inventor could keep up with his unicycling partner. And unlike the Segway it appears to be easier to fall off from! 8-) No costs have been published yet and real production has yet to begin. Like all new ideas and technology, public acceptance will initially be an upward battle - but then, over time it too may be accepted and wide spread.

Video Link

How Far Can You Go?

The question most frequently asked about the Segway is 'how far can it go?' As simple as the question may seem to answer it is not!

The furthest distance you could go would depend upon:

• the terrain - flat, hilly
• the environment - the wind in Wellington can make a big difference!
• what tires are being used - the x2 tires are alot heavier and wider than the i2 ones

All of the maximum distance figures listed on the official Segway site are based on flat surfaces unlike the suburbran Wellington or plain old Wellington for that matter! 8-) So of the sidewalks are ....lets just say at times it is safer to take a  chance on the road.

You mileage/kilometerage will vary, for example a 9.5km trip from the city to homebase used about 5 bars, the return trip, however only used 2 bars. I should point out that the trip home was uphill versus the return trip which was mostly down hill.

On one occasion I even had a tail wind blow/push me and the Segway up hill at a speed of 16 to 18 km/h! yes, the wind can be your friend and also your enemy, especially when it's blowing into you.

To be continued......

Off the Beaten Track #1 - Newlands

One of the joys of a Segway besides being able to get around is to get around to those places off the beaten track. One such track starts at the corner of Wakely Road and Lyndfield Lane in Newlands and ends at the bottom of Centenial Highway near Glover Street.

View Larger Map

Although it is a short (1.4km) track, it is not without its perils. Most of the track is of very loose gravel and is very steep in many places. In hind site I should have had the x2 tires on instead of the less aggressive i2s. And did I mention it is a steep and long drop if you wander too close to the edge?! 8-)

Getting back to home base was via the sidewalk along the Ngauranga Gorge and then up and over the Newland flyover.

Segway i2 vs x2

When I purchased the Segway I made sure I also got the x2 kit with it. The x2 kit is comprised of:

the x2 wide low pressure off-road tires, x2 fenders and frames.

Swapping out the i2 fender and wheels for the x2 takes about 12 to 15 minutes. The x2 tires make the Segway too wide to fit thru normal doors and way too agressive for pavement and street use. But once off the beaten path they are just right for the task. However, there is a trade off, the wider (heavier ) tires take their toll on the batteries and limit the distance you can travel.

As a comparisson, from the official Segway site the i2 has a range of upto 38kms (depending on terrain) and the x2 has a range of upto 19kms! Of course, the i2 figure is based on pavements an streets and with x2, well, it really depends on where you go!