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[on:]

"LoMoR" - Lets Orientate & Map Our Robots (Sonar Based)
Here is a Sonar system i created by combining
an Ultrasonic Measurement Transducer with a Scanning Servo,
mapped onto a (X,Y) LCD Display.

More Details of "LoMoR"at  http://letsmakerobots.com/node/11259

[media]http://www.youtube.com/watch?v=B79WWj1YutQ[/media]

[Reply #1 on:]

wow, looks cool! with the direct drawing on the LCD  

but try a optical sensor, will give you more precision on different surfaces and a sharper edge compared to the sonar.

see my 3d scanner(http://www.designer2k2.at/index.php?option=com_content&view=article&id=22:3d-scan-arduino&catid=13:arduino&Itemid=40) it uses a GP2Y0A02YK to get quite nice results  

[Reply #2 on:]

Thanks for the link - i have admired your 3D system for a while now :o.

Yes the project is only a few days old and its only now that the true ultrasonic scan data is visible on the display.

The Ultrasonic footprint of an object is quite wide (wider than i had calculated) - and yes i will be probe-ing an IR sharp for comparison soon.

The plus point of Ultrasonic system is its scanning range - however the "extra" echos can be miss-leading.

[Reply #3 on:]

with the GP2Y0A02YK you can go for a 2,5m range, is that to small for your project?

always a question of use, the optical sensors are a bit slow at far distances, your system seems to scan the 180° quite fast!

[Reply #4 on:]

Thanks for the Data.
I have since turned the Ultrasonic into vertical alignment and improved the results. (it will work up to 4 meters at solid wall - soft objects reduce the efficiency and echos bounce-ing of objects can interfere )

The Servo is in slow mode at the moment - just for tune-ing . I am expecting it to go 2 or 3 times faster.

To get more accuracy i would have to mount it on a digital servo (ie more in-between steps)

[Reply #5 on:]

I planned to make a robot that would do the same sort of thing as this, but send the data to my computer wirelessly. Would then have a program to use this data to build a map of the environment. Could then do some path finding with the map to tell the robot how to move around objects. I figure the hardest part would be to have the program always know where the robot is, otherwise things would get unsynced and all that.

[Reply #6 on:]

Recommendation would be to use "Processing" as it lends its self to serial data and also Graphic Visualization so at least you can see what is happening.
At present i am experimenting with Making Robots with Senses (the project you see here is "Sight") which will be autonomous ie no external PCs.

[Reply #7 on:]

Recommendation would be to use "Processing" as it lends its self to serial data and also Graphic Visualization so at least you can see what is happening.

I figured I would use C#, because that's the language I've been messing with lately. My programming abilities are much better than my electronic abilities (which aren't that great).

So maybe if I wanted to, throw some XNA graphics into the mix.

[Reply #8 on:]

Updated using :-
Sharp GP2Y0A02YK0F  Long Range IR sensor - mounted vertically.

[media]http://www.youtube.com/watch?v=9qN02ms2CG8 [/media]

Compared to the Ultrasonic, i must say that the results are much cleaner.
This sensor will scan up to 150cm (tested).

[Reply #9 on:]

good choice  

[Reply #10 on:]

Very cool project. I've been planing to do the same or similar for some time. Only I want to send data by wireless from a robot to my PC.

And like TheMastahC I too have been thinking about how to let the robot know where it is when it's moving around ... WITHOUT a GPS. That seems like the real tricky (however interesting) part.

Anyone has ideas about how this can be achieved?

I was thinking about calculating approximately how fast and in which direction it's moving and constantly comparing that to where the objects around it should be. I wonder if it would be possible given the imprecise knowledge of it's location and ditto sensor readings. PLUS the fact that the object may move?!

[Reply #11 on:]

About Processing: Well I wouldn't recommend it. It's easy to program yes but the performance truly sucks. C# is a better solution allthough I'm not sure about the graphics rendering options? Perhaps not much better than Processing?

I recently finished programming a serial oscilloscope in Visual C++ based on Dark GDK (a DirectX wrapper), which I would recommend. It's almost as easy as Processing BUT it performs 1000 better, when it comes to graphics.

Otherwise I believe there are opengl wrappers around that should work with C# too....