Society of Robots - Robot Forum

Mechanics and Construction => Mechanics and Construction => Topic started by: xxstarkxx on September 20, 2012, 03:14:08 PM

Title: Beginner Question: Actuators and Main Control
Post by: xxstarkxx on September 20, 2012, 03:14:08 PM
Hi, I am new to robotics, but for a project I am making a tennis paying robot.  I have most of the aspects for the robot thought out, however I am confused as to what types of actuators I should use in the movement of the robot and what can control these functions.  I have looked into Arduinos and microprocessors, however I cannot find any straight forward answers to my question: what should I use to automatically control the limbs of robot.  I am using image processing and OpenCV to track the tennis ball, but I need something that will carry out my code that and work in conjunction to the image processing.  So, two questions: what should I use to control the image processing (I need something compact, not a laptop or a wireless webcam connected to a laptop) and what should I use to controll the automation of the limbs that can work in conjunction to the image processing.
Should I just use one thing for both or separate?
I have some time and have a general understanding of C++ programming as well. I also have a year for the project.
Thanks a lot for anyone who can help me.
Title: Re: Beginner Question: Actuators and Main Control
Post by: greywanderer012345 on September 20, 2012, 08:37:30 PM
   For any real suggestions, we need more information.

   You say that you have most aspects figured out. Is your bot going to be moving around, or just hitting a ball that comes straight to it?

   Neither an MCU or arduino(it's MCU based) will be able to do that kind of vision processing. I'm looking into the capabilities of the Raspberry Pi, a small $35USD Linux computer, for vision processing. You might want to check it out.

   Why is sending the video to a laptop out of the question?

   This is a huge project, even for an experienced roboticist. If you're serious about completing it within a year, I'd suggest making it a team project, and preparing to spend a LOT of money trying and failing before you get it right. Come up with 10 (or more) ideas, build them all, leave behind what doesn't work, and splice what does.

   Good luck, and don't forget to keep us posted.
Title: Re: Beginner Question: Actuators and Main Control
Post by: Soeren on September 21, 2012, 07:53:20 AM
Hi,

what should I use to control the image processing (I need something compact, not a laptop or a wireless webcam connected to a laptop)
I think your best bet is to use a Pico-ITX or Nano-ITX, as you already know how it works (they're very small single board PCs, so you can write and test the software on a desktop PC).
Couple that with a microcontroller board like this (http://www.digilentinc.com/Products/Detail.cfm?NavPath=2,892,894&Prod=CHIPKIT-MAX32) for sensor/actuator interfacing and you have the hardware to make it happen. (Further interface boards and more here (http://www.digilentinc.com/Products/Catalog.cfm?NavPath=2,892&Cat=18)).


I have some time and have a general understanding of C++ programming as well. I also have a year for the project.
One year and a general understanding C++... No holidays or parties for you in the next 365 - you're lucky if you get 8 hours of sleep each night and don't put off the hard work to later, as many do - you need every hour from now, if you hope to complete as complex a task.

Any chance you could scale it down or get some other project?
Title: Re: Beginner Question: Actuators and Main Control
Post by: xxstarkxx on September 21, 2012, 01:28:15 PM
Thanks for the help.  Oh, and did I say I am working by myself.  No, I am working with a group of three.  My job is actually the largest part.  One person is handling PR and funding.  My other "teammate" is working on the energy parts of it (ie wiring, etc.)  They stuck me with the bulk because I know the most about computer programing and robotics.

The robot is going to move around in order to play functional tennis. A laptop is out of the question because the robot has to function on its own with no outside help.  I had an idea to just program a hardrive and stick the sucker into the robot's head, but I like the Linux Computer and Pico-ITX sounds like a great idea, better than mine.

Thanks again for the help!  I know its going to take a long time, but if I don't finish this year, I can always wait a year to submit the project.

I end with another question that I encountered yesterday while researching, what type of actuator would work the best for an arm that would hit the tennis ball?  Airmuscles or motors?  Furthermore, how do I connect the motors or even the airpump for the airmuscle to the main controller (ie Pico-ITX) so that the computer can control it.  Sorry for all the questions, like I said, I've only made one robot in all my life and all it was was a tiny car that steered away from objects so I would appreciate all the help anyone can give me!