Why Doesn't It Fall Over?

Its a Segway http://www.segway.com

Its got some type of balance sensor in the handle bars. Pushing the bars forward or leaning into them unbalances the sensor. Wheels move forward in an attempt to correct. At rest the platform which you stand on is below the center of the axle.

Its got some type of balance sensor in the handle bars.

Isn't those gyro's

Don't know what the guy's eating.

Could be a gyroscope never had a Segway apart to see what they used to sense handle movement.

I don't think its lamb. unless he got it at a drive through

I heard they had a recall segways because they they had a glitch in thier programing.

Yeah, there was no shutdown warning on the gyros when the battery was almost drained. The gyros would stop spinning unexpectedly and toss the rider off unceremoniously.

"... there was no shutdown warning on the gyros when the battery was almost drained. The gyros would stop spinning unexpectedly and toss the rider off unceremoniously."

Come, now Rory, that's a feature. Now all they need to do is add that feature to a remote.

Segways use a MEMS accelerometer-on-a-chip to sense orientation. Freescale Semiconductor, National Instruments and a number of other companies make these parts, and they're dirt cheap, accurate and far more reliable when compared with mechanical gyroscopes.

ok, so it is an accelerometer not a gyroscope, but the theory still holds, the accelerometer was shutting down unexpectedly. A gyroscope is nothing more than a mechanical equivalent to an accelerometer connected to a servo.

Just like a software engineer, call a bug that could cause serious injury a feature....=D

All joking aside, does anyone remember the wheelchair that Dean Kaman designed and lisenced to Johnson and Johnson that would climb stairs and lift the occupant up on two wheels to reach high shelves and to put them at eye level with standing people? That was Kaman's project "Fred".

The Segway was an outgrowth of that research and was called project "Ginger" as in Fred Astaire and Ginger Rodgers.

they should do what Microsoft would and claim its a feature.

When the battery is drain, its called the auto ejection system. so you don't drive off a cliff or get in a accident with it or something.

They should also pay me for this PR message.

It is a gyroscope, but not in the handle. There is a sensor in the platform, which senses motion from the vertical, and a position sensor, which senses static position, also in the platform. The result of the two is read by an onboard computer, which also does things like control, via PWM, the motors in the wheels, for differential steering, and battery state. They'll do about 20 kph/14 mph in their highest speed range, and come with a key which can be used to set the maximum speed.

I drove one for about 2 minutes at a trade show 5 years ago, then rented three, to tour Washington, DC on, with my daughter and a friend from the UK. What a ride that was. We had a two hour tour, in which we learned to do the "Segway Dance". Riding them is so intuitive, that when you are stopped to listen to the tour guide, you find yourself dancing fore and aft, turning slightly at various times, like some complex, unscripted Pax de Deux with your unwitting partners. Unfortunately, your desire to dance will often last longer than your batteries, so that when you change desires, and partners, in an attempt to rejoin the tour, you have to walk, pushing your Segway along. And those suckers are HEAVY.

Interestingly enough, they are designed so that, without a rider, they take on a slightly front-leaning attitude, rolling forward while progressively leaning farther, until they finally, after 15 feet or so of leisurely travel, lay down, and go to sleep. Rather like me at the end of a long day. I didn't get to see one do it, but did notice, while dismounted from mine, that they definitely lean forward. A slight backward pressure on either handle-bar keeps them still and upright.

Turning them is almost as untuitive as the weight-shifting that causes fore and aft motion. Twisting one handlebar slightly causes the differential application of power to the wheels, in direct proportion to the fore-and-aft weight shift. The result is a very pleasant, smooth, and controllable acceleration in ANY direction. You can even spin them in their own wheel width.

The only difficulty we had to overcome was that they do not allow one to cross curbs (kerbs, to you on the other side of the lake) with any stability. In fact, since they have no mobile suspension travel at all, dropping a wheel over a curb will drop a rider over his or her own teakettle, almost every time. We had to use the wheelchair cuts in the curbs to safely navigate street crossings. And heaven help you if you hit a pot-hole in the process.

But a lot of fun, and no major accidents. Come visit DC, and I'll show you the tour. You'll love it.

Or google "segway by night, DC tours" to find a source of the tours.

Mike

It's a modified Segway. The security staff at our local mall were selected from among thousands to evaluate Segway's forthcoming 'green' beta version. It features an organic

motor.

Sure, they may save money on energy costs by using those green Segways.

But they'll loose so much more in lawsuits from people slipping and falling on the spent fuel emissions.

No! Sell it to software engineers to put in their weekly reports explaining why their code still doesn't compile.

Spaghetti programing !

When I started in the 70's the main aim was to have the computer just help you with tasks and not to create a package, but the specks kept on growing with not enough time to rewrite existing code.

Fortran had a conditional jump and (Rocky mountain) Basic had this (dam) GOTO. The result - one long spaghetti.

The programs outgrew the memory and we had to chain programs and were almost forced to use global variables.

It was only in about 1980 that I got an assembler whereby functions and procedures could be added to the system (more or less equivalent to DLL's) but we never had time to rewrite existing stuff. (Why scratch where you don't itch?)

Alas some of the potent programs went to their graves because it was almost impossible to translate.

Actually the security for the local Target Supercenter around the corner of my house uses one to zip around the parking lot. I asked him Saturday how many times he had been creamed by cars and he said none so far, which means he probably didn't survive past Sunday....