108 reputation
14
bio website
location
age
visits member for 2 years, 1 month
seen Nov 26 '13 at 11:13

Jun
23
awarded  Notable Question
Nov
7
awarded  Popular Question
Oct
25
comment How do I get the total acceleration from 3 axes?
Because the device will be flat and the car will always be moving in the same direction (either forwards or backwards) and we don't have many big slopes in the Netherlands, I think using this simplified equation will be sufficient, thanks!
Oct
25
comment How do I get the total acceleration from 3 axes?
Okay, I read your edit. So it's possible to get a total acceleration of exactly g even when you're accelerating in an angle? The device is to be used in a car, so realistically, it will always accelerate along the z-axis. When I hold the device up as it will be in the car (same tilt), the z-axis is parallel to the earth's surface and points in the direction the car is moving. As it will be used in Holland, hills and mountains are not a big problem and for day to day activities, I think this will be sufficient. Thoughts?
Oct
25
comment How do I get the total acceleration from 3 axes?
Yes, these values change as I tilt the device (it's not a phone). When I lay it flat on the table, Ax, Ay are close to 0 and Az = -1 (gravity pulling down). So when I use the formula mentioned above I think I'm getting close to the actual value. The thing is that I need to detect if the device has a total acceleration of > 2 m/s2 for a period of > 3 seconds. If so, the device is considered to be moving.
Oct
25
awarded  Scholar
Oct
25
comment How do I get the total acceleration from 3 axes?
Okay and how would I do that? Remember, all I have are the values from these 3 axes.
Oct
25
accepted How do I get the total acceleration from 3 axes?
Oct
25
comment How do I get the total acceleration from 3 axes?
Ok, using this calculation I get a final G-value of around 1 when the device isn't moving, so I just subtract 1 to get the final acceleration in G. Then I normalize it to m/s2 and it sits at around 0.24 max, but I guess this is due to limitations of the device. Seems to work.
Oct
25
awarded  Student
Oct
25
awarded  Editor
Oct
25
revised How do I get the total acceleration from 3 axes?
added 153 characters in body
Oct
25
asked How do I get the total acceleration from 3 axes?