Posts Tagged ‘building a robot’

National Robotics Week: Where do you start with building your robot?

Thursday, April 15th, 2010

How is the National Robotics Week going for you? At least one person got back to me and told me that the post was inspiring enough to get them started on building a robot. Bravo! Now that we are that far along, let us take a look at how you could get started with building your first robot.

Before we begin…

I thought I would share some robotics news with you. Did you know that NASA and GM put together a 300 pound robot called “Robonaut2”? NASA is planning to the International Space Station (ISS) and work in the lab! To keep you from straying, I am linking the story at the bottom, not here.

The first step – educate yourself!

In the last post, I mentioned how you will touch on mechanics/mechanisms, electronics, microcontrollers and software among other things in building your robot. There is of course much much more when you build on the complexity of your robots such as design considerations – weight, profile (is it going to be a cube, a spherical robot or what) and so on. I also mentioned you should try to avoid being overwhelmed by all this. If you prepare well and take things in small bites, one step at a time you will get there in no time and maybe you will come back and teach me a thing or two. Whether it is robotics or fly-fishing you always want to have your eyes and ears open to learn from folks.

Where do you learn stuff?

You may be tempted to go out and buy a handful of books. The first step though, is for you to go to the library – your school’s library or a local library near you. If that doesn’t work, use the internet. There are two types of things you want to find out:

1. Learn about robots and robotic applications. Just like Robonaut2, there are hundreds of thousands of robots out there. Reading about what people are doing out there gives you a good idea of what you might want your own robot to do. Of course, there is a more important function that this serves – it inspires to know!

2. Learn what is involved. Pick up a good book on mechanisms. Do you know what the rack and pinion mechanism does? Have you heard of the Geneva Indexing Mechanism? Do you know that you could use a photo-resisting LED to build a line-following robot (more on this later). How about some C programming?

All of us have different inclinations – some of us are more mechanically inclined, some of us are electronics whiz kids. But all of us could use being the Jack (or Jill) who has dabbled in a handful of trades trying to build that gallivanting robot!

Step Two – What do you want your robot to do?

Yes, that’s right. A journey of a thousand miles begins with the first step. You can’t get to the sea without getting your feet wet (metaphorically) and so on. You do get the basic picture – goals first, crazy building in your basement, next.

In the beginning, take small steps. You might want to build a robot that walks, moves or runs a straight line before jumping ahead to a bot that will walk your dog. So, let’s do that. For now, let’s assume you want to build a very, very simple robot, one that follows a line. You may ask – well why not make it even simpler and just make a robot that says “Hello World” or moves, leave alone follows a line. That is fine. Keep it simple (although sound chips etc. maybe a bit much for a beginner, so a talking bot can wait unless you have the electronics background or the right kit).

Okay, you want a robot that moves, and possibly follows a line. What are you going to need?

The inner workings

At the base level a robot needs to be able to perform a task repetitively and (rather) reliably without constant supervision. To achieve this a robot needs:

1. A breadboard (we will talk about all this in a later post, for now, go with the flow), a protoboard or a microcontroller.

2. Depending on what electronics you choose to control the robot, you will want to think about motors, resistors, capacitors and so on.

3. Sensors – robots need a sound sensory mechanism. How does a robot know it is on the right or wrong path? How does a robot respond to changing circumstances? This could be an IR sensor (the thing that makes your TV remote go for example), a photo-resistor, a temperature sensor, or something even cooler like a Hall-effect sensor (yes, go west and build a robot young man or woman, there is great opportunity to stay excited for life!).

4. Your objective – your path, plan, course or whatever it is that you want to build and use to challenge your robot and show it off to friends and that special person… If you are already tuned into robot contests, you know you could build robots based on several interesting challenges such as the robot’s maximum weight, it’s speed while following a course and so on. In the beginning (and yes, I plan to repeat myself) you want to keep things very, very simple.

Your main goal is to build your robot and test functionality as you progress. Once you have got the basics right, you can challenge your robot as you progress.

5. A hand sketch – yes, make a sketch. If you look at the basic books and websites for images of robots, the electronics, the power source and so on, you get a fairly good idea of what you are building. You need to try and put what is on your mind on to a hand-sketch. It doesn’t have to be pretty at all. It has to communicate and commit to paper what you are thinking.

While you make this effort to translate what is on your mind onto a real bot, you may see challenges along the way. If you plan a solar-powered bot, where do you put the solar cells? Is it better to have a flat roof that spans your solar cells? Do you slant the roof so that you can keep the electronics accessible? If you keep the roof horizontal and flat, the robot has a good profile. However, if the roof is slanted, you can easily access the board and replace any resistors or chips that burn out. The path you take will depend on what you find as you test your bot, or on the challenges you set yourself up with.

In the beginning, I would recommend you look up and build the quintessential “line-following robot”. Later you can think about varying on the theme – using a microcontroller, or a lego kit to add complexity, using solar power along with those heavy 9V batteries, or introduce more variations. Once you gain confidence you can build bots that have “eyes” on them, that is, visual sensors, or build and enter a robot that competes in “Robosoccer” contests. If you really feel like challenging yourself, and have the budget, you could build your own robotic swarm! A swarm of robots is a collection of robots that are very similar in function and work as a team to achieve goals such as finding objects, clearing paths and so on.

6. Budget

Robotics, like photography or golf can be an expensive hobby. So some caution is warranted. Try to pick out books from the library. Cheap out on electronics, scavenge where you can and more importantly, keep things simple by planning ahead. Ask around before buying anything and shop around for the best prices.

Tomorrow, let’s dig even deeper into your first “line following robot” and what you might need to get there.

The NASA News Article

http://www.networkworld.com/community/node/60091

Today’s Resources:

Shopping:

1. Craigslist: – http://www.craigslist.org

Yes, the website is the first place to find the best deals all around! Don’t forget to check out Amazon and many other places as well.

2. Jameco Electronics: http://www.jameco.com/

I picked Jameco so that you will have a resource to start with. As far as electronics go, there are many other good sites.

That’s all for today. Let’s tune in tomorrow for more fun with robotics!

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