从陀螺仪android传感器获取旋转度数

Question

到目前为止，我已经在互联网上进行了薄弱的搜索。我正在尝试解决一个问题，我需要从手机起点开始的旋转度数。为了知道用户是否向上或向下移动手机，我使用了加速度计，它一开始有点不稳定，但我设法使其稳定。我现在需要围绕它自身旋转的角度。就像方向传感器一样，它已被弃用。然后我尝试使用磁力计，但我很不稳定。然后，当我使用示例代码时，我确定我想尝试使用陀螺仪：

 // This timestep's delta rotation to be multiplied by the current rotation
 // after computing it from the gyro sample data.
 if (timestamp != 0) {
     final float dT = (event.timestamp - timestamp) * NS2S;
     // Axis of the rotation sample, not normalized yet.
     float axisX = event.values[0];
     float axisY = event.values[1];
     float axisZ = event.values[2];

     // Calculate the angular speed of the sample
     float omegaMagnitude = (float) Math.sqrt(axisX*axisX + axisY*axisY + axisZ*axisZ);

     // Normalize the rotation vector if it's big enough to get the axis
     if (omegaMagnitude > EPSILON) {
         axisX /= omegaMagnitude;
         axisY /= omegaMagnitude;
         axisZ /= omegaMagnitude;
     }

     // Integrate around this axis with the angular speed by the timestep
     // in order to get a delta rotation from this sample over the timestep
     // We will convert this axis-angle representation of the delta rotation
     // into a quaternion before turning it into the rotation matrix.
     float thetaOverTwo = omegaMagnitude * dT / 2.0f;
     float sinThetaOverTwo = (float) Math.sin(thetaOverTwo);
     float cosThetaOverTwo = (float) Math.cos(thetaOverTwo);
     deltaRotationVector[0] = sinThetaOverTwo * axisX;
     deltaRotationVector[1] = sinThetaOverTwo * axisY;
     deltaRotationVector[2] = sinThetaOverTwo * axisZ;
     deltaRotationVector[3] = cosThetaOverTwo;
 }
 timestamp = event.timestamp;
 float[] deltaRotationMatrix = new float[9];
 SensorManager.getRotationMatrixFromVector(deltaRotationMatrix, deltaRotationVector);
 // User code should concatenate the delta rotation we computed with the current rotation
 // in order to get the updated rotation.
 // rotationCurrent = rotationCurrent * deltaRotationMatrix;

这段代码取自他们的文档，我是否可以将其转换为 360 度？或者我可以获得诸如手机偏离起点多少度之类的值？

提前致谢。

Answer 1

使用getRotationMatrix()在两个感兴趣的时间点获取 3x3 旋转矩阵R1和。您想知道与对齐的旋转量。R2angleRR1R2

首先计算R：

R = R1 * transpose(R2)

然后计算这个旋转的角度：

angle = acos((trace(R)-1)/2)

就这些。