使用kinect（libfreenect）加速度计数据

Question

I'm accessing the Kinect Accelerometer in c++ via openFrameworks and ofxKinect and am having some issues with certain angles. If I pitch the kinect 90 degrees downwards I get nan values. I had a look at the getAccelPitch() method and this kind of makes sense since asin will return 0 when there will be values greater than 9.80665 divided by 10.1/9.80665.

The main problem though is after I pitch the device 90 degrees, the roll doesn't seem reliable(doesn't seem change much). In my setup I will need to have the device pitched 90 degrees but also know it's new roll.

Any hints,tips on how I may do that ? Is there an easy way to get the data to draw the kinect's orientation with 3 lines(axes).

I'm trying to detect orientations like these:

Answer 1

The problem is that you are using Euler angles (roll, pitch and yaw).

Euler angles are evil and they screw up the stability of your app, see for example

• Strange behavior with android orientation sensor ,

• Reducing wiimote pitch/roll variations .

They are not useful for interpolation either.

A solution is to use rotation matrices instead. A tutorial on rotation matrices is given in the

Direction Cosine Matrix IMU: Theory

manuscript.