Author Topic: want a new robot tutorial? (Read 255135 times)

Admin · « **on:** June 09, 2005, 03:20:14 PM »

Anyone want a tutorial on something robot related? I can write one up if anyone thinks something is difficult to do/understand. Otherwise I am just guessing what tutorials are useful for you.

Post ideas for some here.

- admin

grated_geek 3000! · « **Reply #1 on:** June 22, 2005, 04:48:03 PM »

Yeah. Please give us a good how-to on how to get grant money and the like.

I'm 13 and can't just poop out $1k.

Admin · « **Reply #2 on:** June 26, 2005, 06:49:53 PM »

ok got u covered

how to raise money for robots:
http://www.societyofrobots.com/robotfunding.shtml

Somchaya · « **Reply #3 on:** January 10, 2006, 10:05:44 PM »

Under the materials section, how about working with plastics? I think there are some that can be hand-sawed and filed relatively easily?

Admin · « **Reply #4 on:** January 14, 2006, 05:12:18 PM »

Ok I made a tutorial on working with my favorite plastic, HDPE . . .

http://www.societyofrobots.com/materials_hdpe.shtml

Let me know if you think it is missing anything important . . .

Somchaya · « **Reply #5 on:** January 15, 2006, 02:23:50 AM »

I actually have a question about the robot you described in the page, or more specifically the camera you
used. What camera is it, and how is it interfaced by a microcontroller? Or was it hooked up to a computer?

On another note, another tutorial that I'd really like to see would be one on how to design bases for robots.
I have some servos, but I'm not really sure how to mount them onto a base, so a tutorial on that would be
extremely useful.

Admin · « **Reply #6 on:** January 15, 2006, 08:45:16 AM »

The camera is the CMUcam, which is interfaced by a serial cable to the cerebellum microcontroller. I dont actually recommend using the CMUcam, as it caused me way too much frustration to get to work. And it still had unexplainable bugs that I could never fix.

As I was writing this plastics tutorial, it occured to me a tutorial on building robot bases could potentially be useful for people . . . and I also have a lot of 'in-construction' pics of my old robots that I could use too.

But the majority of the robots I have built aren't exactly normal robots. This page has a few of my favorite ones I made for example:
http://www.andrew.cmu.edu/user/jsp2/robotics

I also have a thing against books that have step by step instructions on building a particular robot as it takes out the imagination and fun of building a robot. They also seem to forget to only make a very basic design for a beginner to learn . . .

I guess what I can do is write a tutorial more specifically of attaching parts to a robot base, and the reader can decide which parts to actually use, and where to place these parts, on their own.

I was also thinking of a tutorial on how to build a 4 wheel omni-wheel robot . . . mostly cause I have one as a perfect example. Its really simple and its the only one I have ever seen so far.

Is this in line with what you were thinking? Let me know and I will probably have it written in a week or so.

O and as for attaching servos there are two ways. The first is you can buy what is called 'servo tape' and tape it between two flat plates. Servo tape is very strong and holds well, and it has a little flex to it which acts as a basic suspension system. I only recommend it for light weight robots though. The other way is to mount with screws. A servo has 2 holes on both sides designed for screws to go through, and servos come with 2 black rectangular things with holes in it for mounting with the screws. I used this method for that omni-wheel robot in my tutorial. Let me know if this helps.

Somchaya · « **Reply #7 on:** January 15, 2006, 11:47:58 PM »

I think it would be really useful to have building tips in general, for example tutorials on how to attach
motors securely/easily, the pros and cons of the different methods, kind of like what you did with materials
and actuators. Other stuff that would be nice would be tutorials on designing a base, and how to choose
the right motors and wheels.

While a tutorial on building an omni directional robot would be really cool, and something I would definitely like
to see, I too agree that step by step instructions in books aren't that great.. It's like you might want a robot
like that, but not exactly, but you wouldn't really know how to make changes. What I would suggest would be
to maybe have pages describing robots you've built and how you did it (like with the omni directional robot),
but also some other tutorials on general strategies that can be applied to a new project.

Regarding cameras, I've been searching online for a long time on how to use a camera on a robot without
needing a full fledged PC, and CMUCam is the only one I've found so far. I'm reluctant to use it too, but if I find
any other methods to get cameras working on robot microprocessors, I'll definitely post something here.

Admin · « **Reply #8 on:** January 17, 2006, 07:57:37 AM »

Ok I see what you mean.
Ill think about it and probably have something written in a week or 2.

As for cameras, you do not need a full PC. I have seen it done with a old palm pilot and an el-cheapo webcam . . . But yea, I agree, I would perfer it done on a microprocessor too . . .

Admin · « **Reply #9 on:** January 25, 2006, 09:40:03 PM »

Ok here is the completed rough draft of how to construct a robot chassis . . .

http://www.societyofrobots.com/mechanics_chassisconstruction.shtml

I also have some images of mounting the CMUcam but Im too busy to write any more for now . . .

Is this what you were thinking?

Let me know what I should add or rewrite or whatever and I will put it on the site within a week.

Somchaya · « **Reply #10 on:** January 26, 2006, 11:05:23 PM »

The draft is great! I think it's almost exactly what I was thinking about =)

Maybe a little more detail here and there would help, but by and large I think it's pretty complete
and very helpful!

Just a side question, for mounting DC motors, you recommended aluminium mounted on the plastic,
is there a reason not to just use plastic for that too?

Admin · « **Reply #11 on:** January 27, 2006, 07:49:58 AM »

Well, to get an L shaped bracket, you would need to bend the material 90 degrees. Although this is possible with thin sheets of plastic, aluminum is much stronger and more rigid.

You can however get a block of HDPE and cut it into an L shape. This robot I am working on now actually uses a U shaped peice of HDPE I am buying from mcmaster as my chassis and servo mounting bracket combined. If you search for HDPE on their site you can probably find it and see if its what you want.

I guess the main reason I perfer aluminum though is that this area of your robot will recieve higher forces, and if you arent confident it wont break, aluminum is the safer option.

While writing this last tutorial I got the idea of writing up another tutorial on calculating various forces, torque, velocity, and gearing of robots. Sound useful?

Somchaya · « **Reply #12 on:** January 29, 2006, 01:45:30 AM »

I think a tutorial on that topic would be really useful!

However, it might be a good idea to include all the math and all, but also provide a chart at the bottom or something,
that can be used as an easy reference. For example, if the robot is 10 lb, how much torque would be required (or
recommended) by the motors, stuff like that.. So that we can calculate the torque and gearing if we wanted, but there's
still a rough guideline that can be followed, and also to check that the calculations are right.

jonas · « **Reply #13 on:** February 03, 2006, 05:28:25 PM »

What about one on R/c control?

Admin · « **Reply #14 on:** February 05, 2006, 04:08:03 PM »

Well I have tons of experience with R/C using Hitec handheld controllers and servos. Ive made like 5 different servo operated R/C 'robots' and have also operated a microcontroller with an R/C remote. But I have never made my own R/C device, done wireless through a computer, IR remote operation, or done any other type of remote control with robots. I wouldnt trust my advice on it.

The Hitec controller method is really easy . . .
But I am guessing you want the latter method?

jonas · « **Reply #15 on:** February 06, 2006, 09:18:18 PM »

I would like a tutorial on making an r/c control system. But thats not what I was refering to, I know how difficult it would be to do that and onless you want to............

I was talking about just an r/c controller and programming the microcontroller to accept the commands and do what you want it do do.

That would also help me a tad in my project.

Thank you for taking it into consideration,

jonas

Admin · « **Reply #16 on:** February 07, 2006, 08:04:29 AM »

Ok it will probably take me 2-3 weeks to write it cause I am writing a few other tutorials too at the moment.

But to get you thinking, and so you know what is involved, here is a quick run down on how to do it.

Get a R/C remote and reciever at any hobby shop.

Connect a servo wire from the reciever to a digital port on your microcontroller.

When your R/C remote sends a signal to the reciever, the reciever outputs a square wave (meant for a servo). The frequency of this square wave changes depending on your R/C remote command.

Your microcontroller can then determine the frequency and initiate your desired commmand.

A mod to this is use a resistor/capacitor circuit to turn the squarewave into an analog voltage, then have your microcontroller analog port just read the voltage to determine the course of action.

I recommend the 2nd option because it involves much less microcontroller processing . . . but I have to figure out what resistor/capacitor values to use and I am too lazy right now to do it =P

I also had a friend hack a servo to do this. Apparently there is some analog pin in the circuitry that when it recieves a reciever squarewave signal, the analog value changes. So theoretically just hook up a servo to your reciever, and solder a wire somewhere on the servo circuit board (use a multimeter and guessing to find the pin) and attach that wire to the analog pin of your microcontroller.

Admin · « **Reply #17 on:** February 18, 2006, 06:39:57 PM »

somchaya:
ok i made a calculation tutorial for mechanical engineering your robot
http://www.societyofrobots.com/mechanics_statics.shtml

let me know how i can modify it to make it more useful for people

it turns out there is just a lot to talk about and it got really long, so i didnt include gearing or dynamics (like velocity or acceleration)

i will write another tutorial for each of those soon.

Quote from: Somchaya on January 29, 2006, 01:45:30 AM

I think a tutorial on that topic would be really useful!

However, it might be a good idea to include all the math and all, but also provide a chart at the bottom or something,
that can be used as an easy reference. For example, if the robot is 10 lb, how much torque would be required (or
recommended) by the motors, stuff like that.. So that we can calculate the torque and gearing if we wanted, but there's
still a rough guideline that can be followed, and also to check that the calculations are right.

sonial8 · « **Reply #18 on:** February 20, 2006, 10:24:04 AM »

Hello,

Do you have any recommendations for Basic Robotics tutorials which are on site i.e. actual classrooms?

Thanks,
Sonia

Admin · « **Reply #19 on:** February 20, 2006, 10:49:00 AM »

Well, highschools have something called 'First Robotics.' There are also a few universities that have robotics classes, but you would have to be a student there to go to them.

My recommendation is to find a robotics club in your area and join it. Just do a google search for 'your city robotics club.'

Admin · « **Reply #20 on:** February 25, 2006, 07:03:04 PM »

The finished tutorial is here:
http://www.societyofrobots.com/remote_control_robot.shtml

What you need specifically is just the parts I wrote about teleoperation, both at the top and again 2/3rds down at the bottom.

Quote from: jonas on February 06, 2006, 09:18:18 PM

I would like a tutorial on making an r/c control system. But thats not what I was refering to, I know how difficult it would be to do that and onless you want to............

I was talking about just an r/c controller and programming the microcontroller to accept the commands and do what you want it do do. That would also help me a tad in my project.

Thank you for taking it into consideration,

jonas

jonas · « **Reply #21 on:** February 27, 2006, 12:38:28 AM »

Thanks! I'm reading it now. I think its really great that your doing this for people.

zamboniman60 · « **Reply #22 on:** February 27, 2006, 06:53:16 PM »

I know this is totally random, but parallax is sending me a basic 2p40 professional starter kit!
woohoo!

dplass1 · « **Reply #23 on:** March 04, 2006, 09:14:02 PM »

I'd love a tutorial on electronics. I am unsure and scared when it comes to hooking up batteries the "right" direction, how to interface my MCU to motor controllers, and wiring in general (!).

Admin · « **Reply #24 on:** March 04, 2006, 09:25:49 PM »

what about this?

http://www.societyofrobots.com/electronics_basic_components_tutorial.shtml
http://www.societyofrobots.com/electronics_advanced_components_tutorial.shtml

i will admit it is a little too much for a beginner, and a little watered down, but to teach you how to design your own circuits would require way more than a one page tutorial. i took several year long university courses to understand this stuff . . .

instead my electronics tutorial explains the very very basics, and i have a schematics/electronics page that should have all your circuits predesigned for you:

http://www.societyofrobots.com/electronics_tutorials.shtml

i would recommend just putting your circuit on to a breadboard and test your circuits as you make them.

if you think i am missing an important schematic i might design one up for you.

edit: fixed dead links

dplass1 · « **Reply #25 on:** March 04, 2006, 09:28:50 PM »

It's more watered-down than I need. I know Ohm's law and the THEORY of resistors, capacitors, diodes and transistors, but the PRACTICAL application and use of them is what is beyond me.

Admin · « **Reply #26 on:** March 04, 2006, 09:38:36 PM »

i think its just something that you have to learn over time. when i design a circuit, i have to imagine how the electrons flow, and how each component changes that flow. but most of the time i have built something similar already, or i read online how something works.

the schematics i have up explain how they work. you basically need to learn each schematic on your own. after you understand how they work, then you can start to modify them. just copy and reverse engineer them.

start with this circuit which allows you to control a motor with binary output from a microcontroller:
http://www.societyofrobots.com/schematics_h-bridgedes.shtml

it was actually my very first schematic for my very first robot, which i built after spending hours on studying why it works. my first attempt ended up in a meltdown and me burning myself, but my 2nd, and then 3rd, worked really nice.

i will admit that page is a little out dated on my current knowledge, but i think it would really help you learn capacitors and transistors - pratical application.

you can almost build every circuit on your robot without a single calculation, if you understand the basics and imitate other people's circuits.

adiksh · « **Reply #27 on:** March 06, 2006, 10:05:33 AM »

hello,
I would like to know more about line tracers
in particular, what sensors would perform best?
i have used LED and LDR combination but its response is very slow.
I would like to know about cost effective sensors and some algorithms and sensor array types for line tracing

Admin · « **Reply #28 on:** March 06, 2006, 10:11:55 AM »

Have you read this yet?
http://www.societyofrobots.com/competitions_mobot.shtml

This tutorial is probably lacking a little on what you want, so just let me know if you have more questions, or ideas on what I can add to it, to help you.

What is LDR?

For speed and cost effective (and simplicity) you can use two IR emitter-detector pairs, one on either side of the white line, to follow it.

http://www.societyofrobots.com/schematics_infraredemitdet.shtml

Somchaya · « **Reply #29 on:** March 06, 2006, 09:17:58 PM »

Hi! Sorry, I've been really busy recently so I haven't checked the forums much..

The statics page is really good! I think stuff on gearing and required torque on a motor would be useful
for a next step in that =)

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Author Topic: want a new robot tutorial? (Read 255135 times)