Android:计算设备方向的问题

Question

我正在尝试构建一个简单的增强现实应用程序,因此我开始使用传感器数据.

根据此线程(Android罗盘示例)和示例(http://www.codingforandroid.com/2011/01/using-orientation-sensors-simple.html),使用Sensor.TYPE_ACCELEROMETER和Sensor计算方向. TYPE_MAGNETIC_FIELD并不适合.

所以我无法获得"好"的价值.azimut值根本没有任何意义,所以如果我只是将电话向上移动,则值会发生极大的变化.即使我只是旋转手机,这些值也不代表手机方向.

有谁有想法,谁根据给定的例子提高价值质量？

Answer 1

您使用此示例应用程序的方向是什么？从编写的代码来看,支持的唯一方向是纵向或平面,取决于设备.你说"好"是什么意思？

旋转设备时该值不是"好"是正常的,设备坐标系应该是纵向工作,或平面我不知道(Y轴垂直向上,Z轴指向外面屏幕来自屏幕中心,X轴垂直于Y轴,沿着屏幕向右移动).有了这个,旋转设备将不会旋转设备坐标系,你必须重新映射它.

但是如果你想要以纵向方向设备的标题,这里有一段对我有用的代码:

@Override
public void onSensorChanged(SensorEvent event)
{
    // It is good practice to check that we received the proper sensor event
    if (event.sensor.getType() == Sensor.TYPE_ROTATION_VECTOR)
    {
        // Convert the rotation-vector to a 4x4 matrix.
        SensorManager.getRotationMatrixFromVector(mRotationMatrix,
                event.values);
        SensorManager
                .remapCoordinateSystem(mRotationMatrix,
                        SensorManager.AXIS_X, SensorManager.AXIS_Z,
                        mRotationMatrix);
        SensorManager.getOrientation(mRotationMatrix, orientationVals);

        // Optionally convert the result from radians to degrees
        orientationVals[0] = (float) Math.toDegrees(orientationVals[0]);
        orientationVals[1] = (float) Math.toDegrees(orientationVals[1]);
        orientationVals[2] = (float) Math.toDegrees(orientationVals[2]);

        tv.setText(" Yaw: " + orientationVals[0] + "\n Pitch: "
                + orientationVals[1] + "\n Roll (not used): "
                + orientationVals[2]);

    }
}

您将获得标题(或方位角):

orientationVals[0]

Answer 2

来自Tíbó的回答很好,但是如果你记录滚动值,你会得到不规则的数字.(滚动对AR浏览器很重要)

这是因为

SensorManager.remapCoordinateSystem(mRotationMatrix,
                    SensorManager.AXIS_X, SensorManager.AXIS_Z,
                    mRotationMatrix);

您必须使用不同的矩阵进行重映射.以下代码适用于我正确的滚动值:

@Override
public void onSensorChanged(SensorEvent event)
{
    // It is good practice to check that we received the proper sensor event
    if (event.sensor.getType() == Sensor.TYPE_ROTATION_VECTOR)
    {
        // Convert the rotation-vector to a 4x4 matrix.
        SensorManager.getRotationMatrixFromVector(mRotationMatrixFromVector, event.values);
        SensorManager.remapCoordinateSystem(mRotationMatrixFromVector,
                    SensorManager.AXIS_X, SensorManager.AXIS_Z,
                    mRotationMatrix);
        SensorManager.getOrientation(mRotationMatrix, orientationVals);

        // Optionally convert the result from radians to degrees
        orientationVals[0] = (float) Math.toDegrees(orientationVals[0]);
        orientationVals[1] = (float) Math.toDegrees(orientationVals[1]);
        orientationVals[2] = (float) Math.toDegrees(orientationVals[2]);

        tv.setText(" Yaw: " + orientationVals[0] + "\n Pitch: "
                + orientationVals[1] + "\n Roll (not used): "
                + orientationVals[2]);

    }
}

Answer 3

Probably late to the party. Anyway here is how I got the azimuth

private final int sensorType =  Sensor.TYPE_ROTATION_VECTOR;
float[] rotMat = new float[9];
float[] vals = new float[3];

@Override
public void onSensorChanged(SensorEvent event) {
    sensorHasChanged = false;
    if (event.sensor.getType() == sensorType){
        SensorManager.getRotationMatrixFromVector(rotMat,
                event.values);
        SensorManager
                .remapCoordinateSystem(rotMat,
                        SensorManager.AXIS_X, SensorManager.AXIS_Y,
                        rotMat);
        SensorManager.getOrientation(rotMat, vals);
        azimuth = deg(vals[0]); // in degrees [-180, +180]
        pitch = deg(vals[1]);
        roll = deg(vals[2]);
        sensorHasChanged = true;
    }
}

Hope it helps

Answer 4

您是否尝试过组合（传感器融合）类型Sensor.TYPE_ROTATION_VECTOR。这可能会产生更好的结果：转到https://developer.android.com/reference/android/hardware/SensorEvent.html并搜索“rotation_vector”。