问题
I need to find velocity of a device(Samsung Galaxy s3). I've now read quite a lot of stackoverflow questions concerning it, but still confused as for what I should use. My observations so far:
1) Somebody did this to find velocity from accelerometer sensor's data. But in my case the device's movement will not have constant slope or straight trajectory.
2) Integration will give much drift.
3) Kalman filtering can be used but it's hard to implement and CPU consuming
4) Complementary filter can be used, but as far as I understand this only makes sense if accelerometer is being used with gyro to find angle. In my case I need to find velocity
5) Use GPS's getSpeed(). But I'm guessing it's only useful to detect large speed values, such as moving car, therefore isn't sensitive enough for my purpose.
Please suggest me somewhere to start from.
P.S. If you need to know what do I need speed of device for is I need to increase/decrease rendering rate according to the device's movement speed.
来源：https://stackoverflow.com/questions/15648767/finding-speed-of-device-movement