【发布时间】：2018-04-12 19:03:53
【问题描述】：
我正在研究 Xamarin，当我将手机在 0-360 度范围内转动时，我只需要使用陀螺仪传感器来获取手机在桌子上的方向。我已经使用这个传感器与加速度计的融合进行了探索，但我在 java 或 C# 中找不到可理解的代码。我还尝试使用陀螺仪读数来计算角度，但是当我快速转动它或延迟旋转手机时，传感器往往会给我带来不好的读数，同样会增加减少它们的度数。我在参考书目中读到应该将过滤器应用于计算，但我没有在 java 或 C# 中找到代码来测试。在这里，我放置了仅用于陀螺仪的代码。请原谅我的英语。
if (e.Sensor.Type == SensorType.Gyroscope)
{
mAzimuth = this.gyroFunction(e);
}
public float gyroFunction(SensorEvent e)
{
float[] deltaVector = new float[4];
if (timestamp != 0)
{
float dT = (e.Timestamp - timestamp) * NS2S;
Array.Copy(e.Values.ToArray(), 0, gyro, 0, 3);
getRotationVectorFromGyro(gyro, deltaVector, dT / 2.0f);
}
// measurement done, save current time for next interval
timestamp = e.Timestamp;
// convert rotation vector into rotation matrix
float[] deltaMatrix = new float[9];
SensorManager.GetRotationMatrixFromVector(deltaMatrix, deltaVector);
// apply the new rotation interval on the gyroscope based rotation matrix
gyroMatrix = matrixMultiplication(gyroMatrix, deltaMatrix);
// get the gyroscope based orientation from the rotation matrix
var angles = SensorManager.GetOrientation(gyroMatrix, gyroOrientation);
mAzimuth = (float)(this.RadianToDegree(angles[0]) + 360) % 360;
return mAzimuth;
}
private void getRotationVectorFromGyro(float[] gyroValues,
float[] deltaRotationVector,
float timeFactor)
{
float[] normValues = new float[3];
// Calculate the angular speed of the sample
float omegaMagnitude =
(float)Math.Sqrt(gyroValues[0] * gyroValues[0] +
gyroValues[1] * gyroValues[1] +
gyroValues[2] * gyroValues[2]);
// Normalize the rotation vector if it's big enough to get the axis
if (omegaMagnitude > EPSILON)
{
normValues[0] = gyroValues[0] / omegaMagnitude;
normValues[1] = gyroValues[1] / omegaMagnitude;
normValues[2] = gyroValues[2] / 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 * timeFactor;
float sinThetaOverTwo = (float)Math.Sin(thetaOverTwo);
float cosThetaOverTwo = (float)Math.Cos(thetaOverTwo);
deltaRotationVector[0] = sinThetaOverTwo * normValues[0];
deltaRotationVector[1] = sinThetaOverTwo * normValues[1];
deltaRotationVector[2] = sinThetaOverTwo * normValues[2];
deltaRotationVector[3] = cosThetaOverTwo;
}
private float[] matrixMultiplication(float[] A, float[] B)
{
float[] result = new float[9];
result[0] = A[0] * B[0] + A[1] * B[3] + A[2] * B[6];
result[1] = A[0] * B[1] + A[1] * B[4] + A[2] * B[7];
result[2] = A[0] * B[2] + A[1] * B[5] + A[2] * B[8];
result[3] = A[3] * B[0] + A[4] * B[3] + A[5] * B[6];
result[4] = A[3] * B[1] + A[4] * B[4] + A[5] * B[7];
result[5] = A[3] * B[2] + A[4] * B[5] + A[5] * B[8];
result[6] = A[6] * B[0] + A[7] * B[3] + A[8] * B[6];
result[7] = A[6] * B[1] + A[7] * B[4] + A[8] * B[7];
result[8] = A[6] * B[2] + A[7] * B[5] + A[8] * B[8];
return result;
}
private double RadianToDegree(
double angle)
{
return angle * (180.0 / Math.PI);
}
【问题讨论】：
标签： xamarin android-sensors gyroscope