Let's Make Robots!

Razor IMU - 9 Degrees of Freedom - Has anyone used it?

Hello People

I wonder if anyone has any experiance with the Razor IMU with 9 Degrees of Freedom from sparkfun. Is is value for money?

I have found one here http://proto-pic.co.uk/9-degrees-of-freedom-razor-imu-ahrs-compatible/ at what seems a very reasonable price as far as UK prices are concerned (£72 + 6 shipping). Some places are mad expensive, up to almost £120...

dead reckoning algorithms / solutions

Hello All

Me again, flogging a (hopefully not) dead horse.

I wonder if anyone can provide links/guidance/code/insight into dead reckoning programming using the various (relatively) low cost components available to us.

I am thinking of things such as gyroscopes, accelerometers, magnometers etc. At this point I am excluding wheel encoders (since my vehicle is tracked and suffers from slipping tracks) or any form of external input such as beacons or gps etc.

What components for a navigation solution?

Hi All

It must be that my previous question http://letsmakerobots.com/node/28808 was wrongly phrased as I am sure there are plenty of knowledgable people here. Anyway, I will try re-phrase my question.

Could anyone be so kind as to tell me what components would make for a complete navigation module. ie. a module that knows where it is.

I am asking in terms of a small household or garden robot so GPS is probably not relevant.

Which components are good for what (in terms of navigation)?

Hello All

I wonder if anyone could give a complete list (or a pointer to a source) of the various types of components that are usefull in determining the position and orientation of a robot. Essentially anything that is usefull in a complete navigation solution.

My initial thoughts are:

IR distance sensor - usefull for detecting obstacles

Sonar sensor - usefull for detecting obstacles

compass or magnometer - usefull for determining robot orientation. Apparantly when combined with an accelerometer one can have a tilt compensated compass.

How to determine how far has my bot turned?

Hi All

I wonder how you determine how far your robot has turned? I have a newly built catarpillar and find it turns a different amount depending on the surface (and of course obstacles).

How do you pro's determine how much your robot has turned?

I guess one could use some form of becons and triangulation or an onboard compass but are there any other methods you guys & gals use?


My intro and a request for pointers for navigation pseudocode please.

Hello All

I am new here and am currently working on building my first robot. I think I bit off a larger project than I ever should have for a first bot, but have learned a load in the process.

I built a RepRap 3D printer and have since printed out some track links and wheels (a design I found on thingiverse). I have designed my own chasis and am currently on version 4 which seems to be fairly stable.

My bot is a catarpillar..