Android 将设备的磁场X、Y、Z值转换为全局参考坐标系
当您使用_型磁强计传感器时,您可以获得与设备方向相关的磁场强度的X、Y、Z值。我想得到的是将这些值转换成全局参考系,说明:用户拿着设备,测量这些值,然后将设备绕任意轴旋转几度,得到相同的值。 请在下面查找类似问题: 在这个回答中,描述了示例解决方案(这是针对线性加速度的,但我认为这无关紧要): 我用了它,得到了3个值,X总是很小(不要认为它是正确的),Y和Z都可以,但当我旋转设备时,它们仍然有一些变化。如何调整?这一切都能解决吗?我使用简单的卡尔曼滤波器来近似测量值,因为即使设备没有移动/旋转,我也会得到不同的值。请在下面找到我的代码:Android 将设备的磁场X、Y、Z值转换为全局参考坐标系,android,sensors,android-sensors,magnetometer,Android,Sensors,Android Sensors,Magnetometer,当您使用_型磁强计传感器时,您可以获得与设备方向相关的磁场强度的X、Y、Z值。我想得到的是将这些值转换成全局参考系,说明:用户拿着设备,测量这些值,然后将设备绕任意轴旋转几度,得到相同的值。 请在下面查找类似问题: 在这个回答中,描述了示例解决方案(这是针对线性加速度的,但我认为这无关紧要): 我用了它,得到了3个值,X总是很小(不要认为它是正确的),Y和Z都可以,但当我旋转设备时,它们仍然有一些变化。如何调整?这一切都能解决吗?我使用简单的卡尔曼滤波器来近似测量值,因为即使设备没有移动/旋转,
import android.app.Activity;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.opengl.Matrix;
import android.os.Bundle;
import android.view.View;
import android.widget.CheckBox;
import android.widget.TextView;
import com.test.statistics.filter.kalman.KalmanState;
import com.example.R;
/**
* Activity for gathering magnetic field statistics.
*/
public class MagneticFieldStatisticsGatheringActivity extends Activity implements SensorEventListener {
public static final int KALMAN_STATE_MAX_SIZE = 80;
public static final double MEASUREMENT_NOISE = 5;
/** Sensor manager. */
private SensorManager mSensorManager;
/** Magnetometer spec. */
private TextView vendor;
private TextView resolution;
private TextView maximumRange;
/** Magnetic field coordinates measurements. */
private TextView magneticXTextView;
private TextView magneticYTextView;
private TextView magneticZTextView;
/** Sensors. */
private Sensor mAccelerometer;
private Sensor mGeomagnetic;
private float[] accelerometerValues;
private float[] geomagneticValues;
/** Flags. */
private boolean specDefined = false;
private boolean kalmanFiletring = false;
/** Rates. */
private float nanoTtoGRate = 0.00001f;
private final int gToCountRate = 1000000;
/** Kalman vars. */
private KalmanState previousKalmanStateX;
private KalmanState previousKalmanStateY;
private KalmanState previousKalmanStateZ;
private int previousKalmanStateCounter = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main2);
mSensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
mAccelerometer = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
mGeomagnetic = mSensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD);
vendor = (TextView) findViewById(R.id.vendor);
resolution = (TextView) findViewById(R.id.resolution);
maximumRange = (TextView) findViewById(R.id.maximumRange);
magneticXTextView = (TextView) findViewById(R.id.magneticX);
magneticYTextView = (TextView) findViewById(R.id.magneticY);
magneticZTextView = (TextView) findViewById(R.id.magneticZ);
mSensorManager.registerListener(this, mAccelerometer, SensorManager.SENSOR_DELAY_FASTEST);
mSensorManager.registerListener(this, mGeomagnetic, SensorManager.SENSOR_DELAY_FASTEST);
}
/**
* Refresh statistics.
*
* @param view - refresh button view.
*/
public void onClickRefreshMagneticButton(View view) {
resetKalmanFilter();
}
/**
* Switch Kalman filtering on/off
*
* @param view - Klaman filetring switcher (checkbox)
*/
public void onClickKalmanFilteringCheckBox(View view) {
CheckBox kalmanFiltering = (CheckBox) view;
this.kalmanFiletring = kalmanFiltering.isChecked();
}
@Override
public void onSensorChanged(SensorEvent sensorEvent) {
if (sensorEvent.accuracy == SensorManager.SENSOR_STATUS_UNRELIABLE) {
return;
}
synchronized (this) {
switch(sensorEvent.sensor.getType()){
case Sensor.TYPE_ACCELEROMETER:
accelerometerValues = sensorEvent.values.clone();
break;
case Sensor.TYPE_MAGNETIC_FIELD:
if (!specDefined) {
vendor.setText("Vendor: " + sensorEvent.sensor.getVendor() + " " + sensorEvent.sensor.getName());
float resolutionValue = sensorEvent.sensor.getResolution() * nanoTtoGRate;
resolution.setText("Resolution: " + resolutionValue);
float maximumRangeValue = sensorEvent.sensor.getMaximumRange() * nanoTtoGRate;
maximumRange.setText("Maximum range: " + maximumRangeValue);
}
geomagneticValues = sensorEvent.values.clone();
break;
}
if (accelerometerValues != null && geomagneticValues != null) {
float[] Rs = new float[16];
float[] I = new float[16];
if (SensorManager.getRotationMatrix(Rs, I, accelerometerValues, geomagneticValues)) {
float[] RsInv = new float[16];
Matrix.invertM(RsInv, 0, Rs, 0);
float resultVec[] = new float[4];
float[] geomagneticValuesAdjusted = new float[4];
geomagneticValuesAdjusted[0] = geomagneticValues[0];
geomagneticValuesAdjusted[1] = geomagneticValues[1];
geomagneticValuesAdjusted[2] = geomagneticValues[2];
geomagneticValuesAdjusted[3] = 0;
Matrix.multiplyMV(resultVec, 0, RsInv, 0, geomagneticValuesAdjusted, 0);
for (int i = 0; i < resultVec.length; i++) {
resultVec[i] = resultVec[i] * nanoTtoGRate * gToCountRate;
}
if (kalmanFiletring) {
KalmanState currentKalmanStateX = new KalmanState(MEASUREMENT_NOISE, accelerometerValues[0], (double)resultVec[0], previousKalmanStateX);
previousKalmanStateX = currentKalmanStateX;
KalmanState currentKalmanStateY = new KalmanState(MEASUREMENT_NOISE, accelerometerValues[1], (double)resultVec[1], previousKalmanStateY);
previousKalmanStateY = currentKalmanStateY;
KalmanState currentKalmanStateZ = new KalmanState(MEASUREMENT_NOISE, accelerometerValues[2], (double)resultVec[2], previousKalmanStateZ);
previousKalmanStateZ = currentKalmanStateZ;
if (previousKalmanStateCounter == KALMAN_STATE_MAX_SIZE) {
magneticXTextView.setText("x: " + previousKalmanStateX.getX_estimate());
magneticYTextView.setText("y: " + previousKalmanStateY.getX_estimate());
magneticZTextView.setText("z: " + previousKalmanStateZ.getX_estimate());
resetKalmanFilter();
} else {
previousKalmanStateCounter++;
}
} else {
magneticXTextView.setText("x: " + resultVec[0]);
magneticYTextView.setText("y: " + resultVec[1]);
magneticZTextView.setText("z: " + resultVec[2]);
}
}
}
}
}
private void resetKalmanFilter() {
previousKalmanStateX = null;
previousKalmanStateY = null;
previousKalmanStateZ = null;
previousKalmanStateCounter = 0;
}
@Override
public void onAccuracyChanged(Sensor sensor, int i) {
}
}
导入android.app.Activity;
导入android.hardware.Sensor;
导入android.hardware.SensorEvent;
导入android.hardware.SensorEventListener;
导入android.hardware.SensorManager;
导入android.opengl.Matrix;
导入android.os.Bundle;
导入android.view.view;
导入android.widget.CheckBox;
导入android.widget.TextView;
导入com.test.statistics.filter.kalman.KalmanState;
导入com.example.R;
/**
*收集磁场统计数据的活动。
*/
公共类磁场统计CatheringActivity扩展活动实现SensorEventListener{
公共静态最终int KALMAN_状态_最大尺寸=80;
公共静态最终双重测量_噪声=5;
/**传感器管理器*/
私人传感器管理器;
/**磁强计规格*/
私有文本视图供应商;
私有文本视图解析;
私有文本视图最大范围;
/**磁场坐标测量*/
私有文本视图;
私有文本视图磁性文本视图;
私有文本视图;文本视图;
/**传感器*/
专用传感器mAccelerometer;
专用传感器;
私人浮动[]加速计值;
私人地磁价值;
/**旗帜*/
private boolean specDefined=false;
私有布尔值KalmanFileString=false;
/**费率*/
私人浮动利率=0.00001f;
私人最终int GTOContate=1000000;
/**Kalman-vars*/
私有KalmanState之前的Kalmanstatex;
私人卡尔曼斯州以前的卡尔曼斯州;
私人卡尔曼斯泰特(KalmanState)和前卡尔曼斯泰兹(Kalmanstatez);
private int previousKalmanStateCounter=0;
@凌驾
创建时受保护的void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.main2);
msSensorManager=(SensorManager)getSystemService(传感器服务);
mAccelerometer=msSensorManager.getDefaultSensor(传感器类型\加速计);
mGeomagnetic=mSensorManager.getDefaultSensor(传感器类型\u磁场);
供应商=(TextView)findViewById(R.id.vendor);
分辨率=(TextView)findViewById(R.id.resolution);
maximumRange=(TextView)findViewById(R.id.maximumRange);
magneticxtview=(TextView)findViewById(R.id.magneticX);
磁性TextView=(TextView)findViewById(R.id.磁性);
magneticZTextView=(TextView)findViewById(R.id.magneticZ);
msSensorManager.registerListener(此、mAccelerometer、SensorManager.SENSOR\u DELAY\u最快);
msSensorManager.registerListener(此、MGEOMagnitic、SensorManager.SENSOR\u DELAY\u最快);
}
/**
*刷新统计信息。
*
*@param视图-刷新按钮视图。
*/
单击RefreshMagneticButton(视图)时出现公共无效{
resetKalmanFilter();
}
/**
*打开/关闭卡尔曼滤波
*
*@param view-Klaman文件串切换器(复选框)
*/
单击Kalman FilteringCheckBox(视图)时出现公共无效{
复选框kalmanFiltering=(复选框)视图;
this.kalmanFileString=kalmanFiltering.isChecked();
}
@凌驾
传感器更改时的公共无效(传感器事件传感器事件){
if(sensorEvent.accuracy==传感器管理器。传感器状态不可靠){
返回;
}
已同步(此){
开关(sensorEvent.sensor.getType()){
外壳传感器.U型加速计:
accelerometerValues=sensorEvent.values.clone();
打破
外壳传感器。类型\u磁场:
如果(!specDefined){
vendor.setText(“vendor:+sensorEvent.sensor.getVendor()+”“+sensorEvent.sensor.getName());
float resolutionValue=sensorEvent.sensor.getResolution()*NanoTograte;
resolution.setText(“resolution:+resolutionValue”);
float maximumRangeValue=sensorEvent.sensor.getMaximumRange()*NanoTograte;
maximumRange.setText(“最大范围:”+maximumRangeValue);
}
geomagneticValues=sensorEvent.values.clone();
打破
}
if(加速度计值!=null和地磁值!=null){
浮动[]Rs=新浮动[16];
浮动[]I=新浮动[16];
if(SensorManager.getRotationMatrix(Rs、I、加速度计值、地磁值)){
浮动[]RsInv=新浮动[16];
逆矩阵M(RsInv,0,Rs,0);
float resultVec[]=新的float[4];
浮动[]地磁值调整=新浮动[4];
地磁值调整[0]=地磁值[0];
地磁值调整[1]=地磁值[1];
地磁值调整[2]=地磁值[2];
地磁值调整[3]=0;
矩阵多重
private static final int TEST_GRAV = Sensor.TYPE_ACCELEROMETER;
private static final int TEST_MAG = Sensor.TYPE_MAGNETIC_FIELD;
private final float alpha = (float) 0.8;
private float gravity[] = new float[3];
private float magnetic[] = new float[3];
public void onSensorChanged(SensorEvent event) {
Sensor sensor = event.sensor;
if (sensor.getType() == TEST_GRAV) {
// Isolate the force of gravity with the low-pass filter.
gravity[0] = alpha * gravity[0] + (1 - alpha) * event.values[0];
gravity[1] = alpha * gravity[1] + (1 - alpha) * event.values[1];
gravity[2] = alpha * gravity[2] + (1 - alpha) * event.values[2];
} else if (sensor.getType() == TEST_MAG) {
magnetic[0] = event.values[0];
magnetic[1] = event.values[1];
magnetic[2] = event.values[2];
float[] R = new float[9];
float[] I = new float[9];
SensorManager.getRotationMatrix(R, I, gravity, magnetic);
float [] A_D = event.values.clone();
float [] A_W = new float[3];
A_W[0] = R[0] * A_D[0] + R[1] * A_D[1] + R[2] * A_D[2];
A_W[1] = R[3] * A_D[0] + R[4] * A_D[1] + R[5] * A_D[2];
A_W[2] = R[6] * A_D[0] + R[7] * A_D[1] + R[8] * A_D[2];
Log.d("Field","\nX :"+A_W[0]+"\nY :"+A_W[1]+"\nZ :"+A_W[2]);
}
}
SensorManager.getRotationMatrix(gravityCompassRotationMatrix, inclinationValues, gravityValues, magnitudeValues);
SensorManager.remapCoordinateSystem(currentOrientationRotationMatrix.matrix, worldAxisX, worldAxisY, adjustedRotationMatrix);
float sin = adjustedRotationMatrix[1] - adjustedRotationMatrix[4];
float cos = adjustedRotationMatrix[0] + adjustedRotationMatrix[5];
float m_azimuth_radians = (float) (sin != 0 && cos != 0 ? Math.atan2(sin, cos) : 0);