How to find the Angle from pitch, roll and yaw? - qt

Question

I have an accelerometer and gyroscope embedded in a chip, from which I get the x,y,z axis (from accelerometer), pitch, roll and yaw (from gyroscope). Using these values, I have to rotate the 3D image. glRotatef(Angle,Xvector,Yvector,Zvector) How to find the Angle from pitch, roll and yaw? Any equation for this?

Answer 1

Those rotational values you receive from the gyroscope should not be treated as individual rotations about different axes, but time differential the compund rotation. You problem is of the form that you want to find the differential rotation matrix dR for which the differential components can be multiplied in arbitrary order to yield that matrix
dR = dR_x * dR_y * dR_z
= dR_y * dR_x * dR_z
= dR_y * dR_z * dR_x
= dR_z * dR_x * dR_y
= dR_z * dR_y * dR_x
The most easy way to do this, is calculate each of those permutations and take the average matrix of them being dR' and apply orthonormalization.
Then just use this matrix. Forget about glRotate, you don't need it and it got removed from later OpenGL versions anyway.

Answer 2

your answer for pitch & Yaw angle by android acceleration_sensor is:
double angle = Math.atan2(zVal, yVal)/(Math.PI/180) //for pitch
double angle = Math.atan2(xVal, yVal)/(Math.PI/180) //for Yaw
they are tested.
private SensorManager sensorManager;
TextView x;
TextView y;
TextView z;
TextView ang;
String sx, sy, sz;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.l1);
x = (TextView) findViewById (R.id.textView2);
y = (TextView) findViewById (R.id.textView3);
z = (TextView) findViewById (R.id.textView4);
ang = (TextView) findViewById(R.id.textView5);
sensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
sensorManager.registerListener(this, sensorManager.getDefaultSensor
(Sensor.TYPE_ACCELEROMETER), SensorManager.SENSOR_DELAY_NORMAL);
}
#Override
public void onAccuracyChanged(Sensor arg0, int arg1) {
}
#Override
public void onSensorChanged(SensorEvent event) {
if(event.sensor.getType() == Sensor.TYPE_ACCELEROMETER){
float xVal = event.values[0];
float yVal = event.values[1];
float zVal = event.values[2];
sx = "X Value : <font color = '#800080'> " + xVal + "</font>";
sy = "Y Value : <font color = '#800080'> " + yVal + "</font>";
sz = "Z Value : <font color = '#800080'> " + zVal + "</font>";
x.setText(Html.fromHtml(sx));
y.setText(Html.fromHtml(sy));
z.setText(Html.fromHtml(sz));
double angle = Math.atan2(zVal, xVal)/(Math.PI/180);
ang.setText(String.valueOf(angle));
}
}