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Topic: big balancing robot (Read 4278 times) previous topic - next topic

immaturespartan

If you have played borderlands,  then you know claptrap
If not.. I feel sorry for you. The point is I am making a 40 inch tall robot with arms and that balances on one wheel. I dont know what platform to run him off of though. Beaglebone is a candidate, and so is arduino and raspberry pi. I also have a laptop i am not afraid to sacrifice ro run ROS on, but i do not knpw how i would get started with all of my components compatible to arduino and raspberry pi because my components are all breakouts. Is arduino powerful enough to handle processing the movement of 16 servos, a face tracking eye (I know that image processing is pitiful on arduino but I have seen it work) a speech shield, and the balancing wheel on a motor driver? I have about 130$ to spend on my processor if i do not use my computer. If you have any ideas please throw them at me. Or just call me crazy for trying to build a real claptrap. btw the board for the speech is easy vr.
I hope you guys can help!
-Jack D

zoomkat

What you see in movies and video games do not have to obey the laws of physics and current technology. That being said, using high speed gyroscopes to vertically stabilize the bot might work.
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Why I like my 2005 Rio Yellow Honda S2000  https://www.youtube.com/watch?v=pWjMvrkUqX0

immaturespartan

Wow! Thanks for the reality check, I was really starting to think I was in the dream world. I know what I'm doing and I have my share of experience in robotics, just not at this size. I just want some input on the controller to use from people with more know-how on this level of robotics. Ideally the board iether has a large community or already has some programming for it, as programming isn't my strong suit. Otherwise I am only limited by the fact that it has to communicate with serial tx rx serial ports for my gyro breakout and my servo breakout, same with my motor controller (that is IF the board does not have any of those on board which would be easy) the robot won't be running a Chabot by the way, (duh) I just was going to use a crush shield or chip. Whatever is compatible with my controller.

immaturespartan

I am also using a flat wheel so moving back and forth is the only balancing

mirith

This is a terribly complex problem unfortunately.  You really should split it up into two parts:
1) Balancing
2) Moving

This means you'll probably need separate motors for both.  Also, how will you keep it stable from side to side?

immaturespartan

The wheel is a Flintstone style flat roller type wheel. I was planning on making a large gyroscope inside of the thing, but the amperage draw would be too excessive for just for a bit of style, I would probably end up using another motorcycle battery. The one I have now is 8 ah and 12v (duh)

immaturespartan

By the way how would I do one motor for direction and another for balance? Sounds like a good idea, but can't see how that would work.

mirith

Well, one motor would control the drive wheel, and another something, mounted to the wheel, would control the tilt of the robot, doing the balancing.  This way you don't have to worry about combining movement with balancing in the same control loop.  However, you would need to be able to balance along 2 axis (Forward and back, and side to side).

However, I want you to think very carefully about this, as it is NOT a simple problem.  Ever ride a unicycle?  So, when it accelerates, inertia will tilt the body back, and same with deceleration.  However, what happens when you want to turn?  How do you even turn, you have only two directions of motion, forward and back.  This means you need to Tilt the robot to turn sideways.  Or the wheel needs to turn (which given its reference, the robot would actually turn, not the wheel).
Now you have to balance while either 1) The robot is tilting or 2) while the wheel rotates around, and now the axis of movement has shifted changing the balance..

I'm pretty sure that this is on the level of PhD or Post-Doc research.  Assuming parts even exist.  If you could build a working prototype in your garage, I imagine people will have jobs for you.  Good luck!

immaturespartan

By the way how would I do one motor for direction and another for balance? Sounds like a good idea, but can't see how that would work.

immaturespartan

Thanks guys this really helps. I think I will use an ez robot platform with seperated arduino balancing. I just now need to figure out how to make it turn... the Flintstone wheel I am going to have to keep, because I do not want to worry about side to side. I think I may use a counter rotating gyro to slowly accelerate whilst another does the same, when one gyro stops, the inertia turns the robot, and one stays going to keep the robot balanced. This is a lot more complex, but it is my only option that doesn't have a huge gyro running the entire time, sucking up all of my energy.

immaturespartan

Well, so far has been a bust. I need a board that can do everything I need. I can use a computer but can ros make a balancing robot?

zoomkat


Well, so far has been a bust. I need a board that can do everything I need. I can use a computer but can ros make a balancing robot?


Previous post concerning balancing robots. Perhaps your project is too ambitious.

https://www.google.com/search?as_q=balancing+robot&as_epq=&as_oq=&as_eq=&as_nlo=&as_nhi=&lr=&cr=&as_qdr=all&as_sitesearch=http%3A%2F%2Fforum.arduino.cc%2Findex&as_occt=any&safe=images&tbs=&as_filetype=&as_rights=
Google forum search: Use Google Search box in upper right side of this page.
Why I like my 2005 Rio Yellow Honda S2000  https://www.youtube.com/watch?v=pWjMvrkUqX0

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