Society of Robots - Robot Forum
Mechanics and Construction => Mechanics and Construction => Topic started by: [email protected] on February 17, 2012, 07:44:24 PM
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Hi, I am a Mechanical Engineer with plenty of experience, but I have no robotic/controls experience.
I would like to build a device to balance my motorcycle when I stop at a stop light so that I don't have to put my feet down. I would like it to be as small and light as possible. I would like it to be able to attach to the storage/gear rack at the back of the motorcycle.
I know how to do everything except build the balancing part and what components are required to balance the motorcycle.
The motorcycle, with me on it weighs about 700lbs.
I would like to control the handle bars at the stop light and the idea is that I would pull up to the light and as I stop the balancer will take over and I will hold the handle bars still.
I do not know how to write any software, and I do not know how to choose any electronic components. I believe it will need to run off of 9V power supply on the bike.
Can anybody help me with this project?
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Add a side car?
Seriously though, what are you talking about here? Do you want to automatically deploy a kickstand? Do you want to use some sort of gyroscope juju?
One does not simply.... balance a motorcycle.
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Training wheels!
But ya, what Resilient said.
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Thanks for responding - I would like to be able to do something like experiment 1 of this youtube link.
Motor Bike Robot (http://www.youtube.com/watch?v=0312BNqIBFI#)
That means I would be sitting still at a stoplight and not turning the steering wheel. It would be pushed a little by strong winds. And if it started to fall I would just put my feet down.
I don't know what for sure would be needed. I guess a gyro, a big motor, some controller software, a big weight. But I don't know how to make it all work.
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it's also quite similar to this...
Unicycle: Phase1: Lateral balance (http://www.youtube.com/watch?v=xNgPIqjqj5k#)
and this one too...
Unicycle Robot made by KSA (http://www.youtube.com/watch?v=FbkJxZkjOSM#)
notice that it is only lateral balance that is required.
it sure looks simple but man is it ever over my head. maybe the controlling software and components can be purchased and all i would have to do is buy a big enough motor and slap on a 100lb weight. DONE! LOL
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I am not a mechanical engineer. It sounds like you are not one either. But I do know that spinning heavy things quickly can result in serious failures. Engineers died some years ago when a containment vessel for flywheel testing failed during a low speed test.
Also this:
CR X flywheel goes KABOOOOOOOOOM (http://www.youtube.com/watch?v=n0TxZFDLa3w#)
You will be sitting on that quickly rotating piece of material.
Be careful with this one.
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I am an ME. Look at the vids and you can see the rotational speeds are quite low. I'm always careful.
Good to get different perspectives though because the DMV will ask those types of questions too.
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Dear Pat Vulk,
So many doubters! I say experiment away! While I unfortunately don't know too much about software stuff (also an ME), I can at least point you to this: http://en.wikipedia.org/wiki/Gyro_monorail (http://en.wikipedia.org/wiki/Gyro_monorail) and this: http://www.aqpl43.dsl.pipex.com/MUSEUM/LOCOLOCO/brennan/brennan.htm (http://www.aqpl43.dsl.pipex.com/MUSEUM/LOCOLOCO/brennan/brennan.htm) . This kind of design doesn't seem to need as much in the way of intelligent motor control. I think it could basically be achieved with a pair of weighted wheels mounted on either side of your bike.
To ease the fears of some of these other commenters, maybe try this on a weighted bicycle first and show us the results.
~Tom
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In "real life" you balance by turning the handle bars to move/ accelerate the contact point to the right or left of the center of gravity which causes the bike to rotate to the left or right. This is easier and more effective when moving because in addition to just moving the contact point to the right or left, you also accelerate to the right or left causing the vehicle to rotate to the left or right.
Example, riding along you turn the handle bars to the right - the contact point moves and accelerates to the right, the bike inertia lags and it tips to the left setting you up for a left turn. (This is why it is hard to learn how to ride a bike - do a search on "non-minimum phase").
You can do the same thing at a stop, but you have less control authority because the distance you can move the contact point is limited by the trail in the front suspension. But with practice, it can be done (up to a point...)
A simulation using a tool like Matlab / Simulink would go a long way towards figuring out your control algorithm. http://www.mathworks.com/matlabcentral/fileexchange/27694-nxtbike-gs-self-balancing-bike-robot-by-steer-into-fall (http://www.mathworks.com/matlabcentral/fileexchange/27694-nxtbike-gs-self-balancing-bike-robot-by-steer-into-fall) is an example of how to do it with Legos.
The "track stand" method helps with the control authority problem
track stand 101 (http://www.youtube.com/watch?v=B3KJEN_KrVM#)