Quad encoder problems

[SteveB]

Smitty,
Here is an interesting link to a site on a homebrew UAV. It deals with the problems associated with accurately calculating attitude of an aerospace vehicle. You may get some ideas you can implement on a smaller/limited scale to achieve your objectives.


Better link, check out items under "Design:". Particularly AHRS and Sensors.

HTH,
Steve

EDIT: One final note, there is a reason the off the self systems are very expensive. It is not a trivial task!

[smitty505000]

Thanks for all the info guys!! I have been doing some reading and I see what you mean. At least I know how to read encoders now.

I do have an idea how to make the artificial horizon. I need to do some tests but the basic idea is to use a couple or RC heading hold gyros. I have a futaba gy401 and have already done some tests on it. It outputs a pwm signal to move a servo. The down side is It only tracks about 30-35 degrees of movment. Now here is the interesting part. It can be reset to 0 via another pwm signal! So here is my idea. Have it set up to read movement and output to the pic. Then in the program have it set to reset when it reaches its limit. A counter will keep track of which set of 30-35 degrees it is on. This should be able to keep track with a certain amount of drift or error. Depending on how much error there is, I thought it could also be reset when level to the ground. To do this I can use a futaba pa1 pilot assist unit. This unit detects the light to dark difference optically and knows when it is level. It outputs 2 pwm channels that can reset both gyros! Hope this makes sense, I am in a hurry.

What do you think?

Smitty