I'm extremely new to the Arduino community, only just started to have a look at it, as I think it might be what I need for my final year mechanical engineering project. I intend on designing and manufacturing a self balanced 2 wheeler.
Is this something I can do using Arduino? Bearing in mind that I want to control the whole thing using a ps3 controller(Or any sort of wireless controller) possibly using a joystick to control each wheel.
For a final project in mechanical engineering, you really should be able to define your requirements better. What does "rotate and spin at the same time" mean? A wheel is attached to an axle. From my experience, the wheel can rotate about the axle. Bad things happen when the wheel does anything else.
To get a better idea of what I mean, have a look at this video from 5:21 - 5:00
If you have two motors, each with a wheel on it, you will need to independently control those motors. That being said, you will need a dual motor driver of some sort. For low-power motors, try this dual motor driver board.
PaulS:
For a final project in mechanical engineering, you really should be able to define your requirements better. What does "rotate and spin at the same time" mean? A wheel is attached to an axle. From my experience, the wheel can rotate about the axle. Bad things happen when the wheel does anything else.
How do we get the video to play in reverse?
I meant to say 5:21 - 6:00, i've amended this now. When I say spin, I mean the obvious spin around the axle, and when I say rotate, I mean rotating the entire wheel axle assembly, as you would do when turning.
androidfanboy:
So you need a differential drive train? Unfortunately this is probably not the place to ask lol.
Watch the video - it is a lot more complex than a differential.
What's in the video is a triangular platform with a wheel mounted on a caster at each corner. I presume a motor can cause the wheels to rotate so as to drive the machine forward and some other motors cause the casters to rotate so as to change direction.
I reckon a final year student should have been able to explain that.
IMHO it would be quite impractical to implement a system like that on a two-wheeled device - when the casters are rotated it would just fall over.
Two-wheeled self-balancing machines have been around for years. They just have a stepper motor or a DC motor with an encoder for feedback driving each wheel. They do not have steering wheels.
I would expect a final year student to know that. Some of his class-mates probably have self-balancing boards for getting around the campus.
Maybe he's onto something: a 2-wheeled thing that can balance like a Segway and can also drive like a bicycle. That solves the problem of limited maximum speed with the normal balancing bot.
I plan on using Gyroscopes for balancing. Specifically 2 gyros rotating counter to one another to eliminate the precession you would get with just one.
Except precession is what makes gyros balance. Two of them counter-rotating will cancel out the balancing effect. They will still resist having their axes moved, which means that it will hit the floor slower. It will also resist maneuvering, which may not be desirable either.
There's Engineering as mathematics and there's Engineering in knowing which end of the screwdriver to hold. Universities teach the first part. Life experience teaches you the second part.
In my time at the university (some 20 years ago) most students were interested enough in their subject that they made sure to get those life experiences by themselves, just out of their own interest. Such as mechanical engineering students taking apart everything just to figure out how it works (the good ones also managed to put things back together and in a working order).
For the balancing thing, this sounds very much like the robot I used over 20 years ago in a "real time programming" course, where we had to use TurboPascal to read IRQs on an AT PC. Or maybe it was a 386SX20 already. I forgot... We had five light sensors upfront to follow a line.
We used a third wheel for balance but other than that it was the same. PWM to set the motor speed, independent speeds, so rotate one forward and the other backwards and before you knew it the bundle of control wires was totally twisted.
It sounds like progress has been made. The third wheel has been eliminated - together with the basic knowledge of how wheel speed and movement of a vehicle are related.
