View Single Post
  #2   Spotlight this post!  
Unread 15-01-2009, 21:10
Tanner's Avatar
Tanner Tanner is offline
Registered User
FRC #1261 (Roblions)
Team Role: Programmer
 
Join Date: Jan 2007
Rookie Year: 2007
Location: Suwanee, GA
Posts: 311
Tanner is a splendid one to beholdTanner is a splendid one to beholdTanner is a splendid one to beholdTanner is a splendid one to beholdTanner is a splendid one to beholdTanner is a splendid one to behold
Re: Noisy Accelerometer

Quote:
Originally Posted by Russ Beavis View Post
This may be a bit of a stretch but when you're using graphs in LabVIEW, look out for autoscaling of axes. Is it possible that you're not really seeing noise but are instead observing a change in the acceleration axis' scale?

In LabVIEW, if you right-click on a graph's axis, you can change a number of parameters such as autoscaling and linear/log scaling.

Just a thought.

Has another else observed noisy accelerometer readings while driving motors?

Another test to run - put your robot on a stand so that it's not moving at all and observe the accelerometer readings with the motors off and motors running. Is there a difference even though the robot is on a stand? If so, you're probably coupling some motor current noise into your accelerometer reading (or into the power supply for the accelerometer).

Russ
We had the graphs at autoscale, but realized how stupid that was for differentiating between really tiny noise and actual values. They now are at a range at like -5 to 5 or -20 to 20. I can't remember.

The immobile robot motor test sounds like a good test. We'll have to try that on Saturday to see if the motors actually affect the sensor.

Thanks
-Tanner