如何使 Android 中的方位角和度数不那么不稳定

Question

首先我使用了 TYPE_ORIENTATION，但这个已经贬值了。因此，我将代码更改为更新的版本，并按照 this post 中的建议使用了 TYPE_ACCELEROMETER 和 TYPE_MAGNETIC_FIELD。

// Initialize android device sensor capabilities
mSensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
accelerometer = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
magnetometer = mSensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD);

然后在onResume()中，我使用了这个：

// For the system's orientation sensor registered listeners
mSensorManager.registerListener(this, accelerometer, SensorManager.SENSOR_DELAY_UI);
mSensorManager.registerListener(this, magnetometer, SensorManager.SENSOR_DELAY_UI);

及以下我使用的：

@Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {
    // not in use
}

float[] mGravity;
float[] mGeomagnetic;

@Override
public void onSensorChanged(SensorEvent event) {
    if (event.sensor.getType() == Sensor.TYPE_ACCELEROMETER)
    mGravity = event.values;
    if (event.sensor.getType() == Sensor.TYPE_MAGNETIC_FIELD)
    mGeomagnetic = event.values;
    if (mGravity != null && mGeomagnetic != null) {
        float R[] = new float[9];
        float I[] = new float[9];
        boolean success = SensorManager.getRotationMatrix(R, I, mGravity, mGeomagnetic);
        if (success) {
            float orientation[] = new float[3];
            SensorManager.getOrientation(R, orientation);
            float azimuthInRadians = orientation[0];
            float azimuthInDegrees = (float) Math.toDegrees(azimuthInRadians);
            if (azimuthInDegrees < 0.0f) {
                azimuthInDegrees += 360f;
            }
            float degree = Math.round(azimuthInDegrees);
            directionHeading.setText("Heading: " + degree + " degrees");

            // Create rotation animation
            RotateAnimation ra = new RotateAnimation(currentDegree, -degree,
            Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF,
            0.5f);

            // How long the animation will take place
            ra.setDuration(210);

            // Set the animation after the end of the reservation status
            ra.setFillAfter(true);

            // Start the animation
            image.startAnimation(ra);
            currentDegree = -degree;
        }
    }
}

老方法很精确，一点也不抖。但是现在，以不贬值的方式，它震动很大。为什么会这样，我该如何解决抖动问题？

Answer 1

解决方案是应用 (LPF) 低通滤波器。它很顺利，现在工作得很好。我在这里找到了解决方案：Low Pass Filter

如何使 Android 中的方位角和度数不那么不稳定

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