Let's Make Robots!

explorer :)

Navigate around via IR

This is my first robot. The photo shows the way it looks for now, but it's a just 'prototype' yet and it will evolve ;)

It has been inspired by fritsl's 'how to build your first robot' as you probably can see (this one and many other tutorials/tips are SOOOOOOOOO helpful, THANKS!).

I made my own IR sensor using a IR LED and a phototransistor or whatever it's called.. The sensor cost me about 3$. I used some wood as chassis, nails as axles and a glue gun OF COURSE ;) and some LEGO wheels I had.. I've also put 3 LEDs on the top just to know which part of code is being processed (which apparently doesn't always reflect in what the robot actually does :)

All in all..... It's not perfect :) First of all it drives to fast (hard to react on time, before it hits the wall :) and doesn't drive straight due to defferences in motors... So now after I got a little into picaxe stuff I'll improve the project probably using modified servos as geared motors... Will make a video then :)

 

The robot is basicly supposed to do this:

 

Drive forward, check whats in front...

If we got something then stop and go back a little...

Then using 'random' command choose which way to look first (left or right)

If the first look shows some space to drive, go there, if not, look the other way

If the other way is free, go there, if not then turn around and go....

 

and so on, so on... as long as we have power :)

 

For me the cost to build it was actually 2 times lower because the only thing I didn't have at home at that time was picaxe...

 

Hope to do the modifications soon...

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got some xmas stuff to do so it'll take some time but i will try to do the vid as fast as i can :)

i covered the IR LED with a heat shrinking tube to make it more accurate (receiving only whats in front of it). Its also easy then to adjust it just by cutting the tube or putting a new, longer one. I quess the sensor had quite a range, maybe 1m...? but then it received signals from the sides also, i guess.. and was sometimes spinning around and finding no way to go... And also some false signals were going to the receiver straight from the LED.. I will work more on it later and will also do more research concerning the range.

Many thanks for your opinions again :)

that little guy looks awesome. when do we get a video?
I'm curious, you said you made your own IR sensor. What sort of range does it have?

Way cool :)

I recomend you to use a speaker instead of the LED's to know what the robot is doing. It is a lot easier to hear a "boouuip", and seperate it from a "bep beep beep" or a "beepbeep boop buup".. than some LED's making flashes behind the box the robot is behind ;)

Also, yes, slow motors / very geared motors are a must for your first project. Get some new geared motors, they are cheap, and will do all for you, noone can learn from a fast robot, and you can see all a slow one is doing.. and as a matter of fact it looks cooler when it is so slow that you can tell what it is doing :)

Thanks for your good opinion on it.. :)

well, maybe it's not that hard to write the correct code for this robot and understand it, it's just that this kind of propulsion is not reliable enough.. It is possible to enhance the range of the IR sensor (actually I had to short it) but then the robot reacts to early and sometimes gets false signals because then thinks that a 1 meter wide hole is not big enough for him to drive through :) and also it's hard to find such long distanses at home so it won't just stand in the middle of the room and think that has no way to go... It's supposed to penetrate the little spaces like under the tables and stuff so it has to be slow and move quite close to the objects :)

And also, it isn't actually NOT reacting because of the speed but after getting command to reverse, it has to little power and probably grip to stop before the wall comes :) when using hands as objects and helping by moving hands a little back as it goes towards them, then it works just fine.

Thanks for good words again.