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# Physics/Acceleration and rotation

Question
I am developing an android application which detects potholes in the road. For this I use the built in accelerometer in the phone. I can measure the acceleration in 3 direction (x,y & z) and also the 3 rotation angles(azimuth,pitch and role).But I don't know how to detect a pothole using these values. I referred so many papers regarding this, but I don't understand it.

You don't really detect a pothole with these values.  You detect the fact that you've run over a pothole with them.  Are you trying to create a map of them by running over them?  You certainly can't "detect" them if what you mean is to avoid them.  If a car is accelerating smoothly or traveling at a constant velocity, you'll have small acceleration values.  Add all the accelerations together quadratically (ax^2+ay^2+az^2), set some arbitrary threshold (maybe you can program a slider for the level), and above that threshold you've detected a pothole.  It should be that simple.

Physics

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#### Dr. Stephen O. Nelson

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