我正在研究 Xamarin，当我在 0-360 度范围内转动手机时，我只需要使用陀螺仪传感器来获取手机在桌子上的方向。我已经使用此传感器与加速度计的融合进行探测，但我在 java 或 C# 中找不到可理解的代码。我也尝试用陀螺仪读数计算角度，但是当我快速转动它或延迟旋转手机时，传感器往往会给我一个糟糕的读数，同样会增加减少它们的程度。我已经在参考书目中读到应该将过滤器应用于计算，但我没有找到 java 或 C# 中的代码进行测试。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);
}
我设法获得了一个工作代码版本，用于获取加速度计的位置。我正在使用Xamarin.Essentials Nuget数据包，代码如下：
-
首先，从Microsoft文档中获取并进行了少量修改，我打开加速度计：
public void ToggleAcceleromter() { try { if (Accelerometer.IsMonitoring) { Accelerometer.Stop(); Accelerometer.ReadingChanged -= Accelerometer_ReadingChanged; UserDialogs.Instance.Toast("Gyroscope mode disabled, tap again to enable."); } else { Accelerometer.Start(SensorSpeed.Ui); Accelerometer.ReadingChanged += Accelerometer_ReadingChanged; UserDialogs.Instance.Toast("Gyroscope mode enabled, tap again to disable."); } } catch (FeatureNotSupportedException fnsEx) { UserDialogs.Instance.Toast("Gyroscope mode not supported in this device."); } catch (Exception ex) { UserDialogs.Instance.Toast("Gyroscope unkown error, please report tu bugs@xxxx.com"); } }
然后，在处理程序中，我使用了以下代码：
void Accelerometer_ReadingChanged(AccelerometerChangedEventArgs e)
{
var data = e.Reading;
var roll = Math.Atan(data.Acceleration.Y / Math.Sqrt(Math.Pow(data.Acceleration.X, 2.0) + Math.Pow(data.Acceleration.Z, 2.0)));
var pitch = Math.Atan(data.Acceleration.X / Math.Sqrt(Math.Pow(data.Acceleration.Y, 2.0) + Math.Pow(data.Acceleration.Z, 2.0)));
var yaw = Math.Atan(Math.Sqrt(Math.Pow(data.Acceleration.X, 2.0) + Math.Pow(data.Acceleration.Z, 2.0)) / data.Acceleration.Z);
Debug.WriteLine("roll: " + roll.ToString() + ", pitch: " + pitch.ToString() + "yaw: " + yaw.ToString());
}
这三个变量中，我们可以看到一个稳定的数字，表示设备在三个不同轴上的位置。就我而言，我想为正面轴(俯仰(的运动获取一个从 0 到 100 的数字。我用这段代码做到了，它显示条目中的值并移动滑块：
double unsignedYaw = 0;
if (pitch < 0) {
unsignedYaw = pitch * -1;
} else {
unsignedYaw = pitch;
}
double scaleMiddle = 50;
var scaledYaw = unsignedYaw * scaleMiddle / 0.5;
double finalValue;
if (pitch > 0) {
finalValue = scaleMiddle + scaledYaw;
} else {
finalValue = scaleMiddle - scaledYaw;
}
if (finalValue < 1) {
moveValue.Text = "1";
sliderSteps.Value = 1;
} else if (finalValue > 1 && finalValue <= 100) {
moveValue.Text = finalValue.ToString();
sliderSteps.Value = finalValue;
}