Question

我在Google地图上绘制一条折线，取决于半径（1 - 100米）。一旦绘制了心脏，用户需要在心脏边界上行走并且需要从头到尾完成（从底部开始然后向左然后向右然后再向下开始）。

我能画出心脏，我得到360分（latlng）。这是我的代码，它将绘制心脏和图像。

private void initPath() {
    path = new PolylineOptions();
    path.color(ContextCompat.getColor(mActivity,R.color.heart_green));
    path.width(25);

    // offset to bottom
    double offsetY = getY(Math.toRadians(180));

    for (int angle = 0; angle <= 360; angle++) {
        double t = Math.toRadians(angle);
        double x = getX(t);
        double y = getY(t) - offsetY;
        //Log.d(TAG, "angle = " + angle + "(x = " + x + ",y= " + y + ")");

        //convert x,y to lat lng
        LatLng latLng = getLatLng(x, y, center);
        path.add(latLng);

        heart360Points.add(latLng);

    }

}

private double getX(double t) {
    return radius * 16 * Math.sin(t) * Math.sin(t) * Math.sin(t) / HEART_RATIO;
}

private double getY(double t) {
    return radius * (13 * Math.cos(t) - 5 * Math.cos(2 * t) - 2 * Math.cos(3 * t) - Math.cos(4 * t)) / HEART_RATIO;
}

private LatLng getLatLng(double dx, double dy, LatLng centerHeart) {
    return new LatLng(centerHeart.latitude + Math.toDegrees(dy / EARTH_RADIUS),
            centerHeart.longitude + Math.toDegrees(dx / EARTH_RADIUS) / Math.cos(Math.toRadians(centerHeart.latitude)));

}

这是心脏形象。

但每当我试图在心脏边界上行走时，GPS的位置太多波动，所以我永远无法完成心脏的行走。我目前每秒请求位置。

这是我的位置代码。

 private static final long FASTEST_UPDATE_INTERVAL_IN_MILLISECONDS = 2000 ;
 @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.love_lead_perform);
    getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
    mApiClient = new GoogleApiClient.Builder(this)
            .addApi(ActivityRecognition.API)
            .addConnectionCallbacks(this)
            .addOnConnectionFailedListener(this)
            .build();

    mApiClient.connect();


    mFusedLocationClient = LocationServices.getFusedLocationProviderClient(this);
    mSettingsClient = LocationServices.getSettingsClient(this);
    createLocationCallback();
    createLocationRequest();
    createLocationSettingsRequest();


} 

private void createLocationSettingsRequest() {
    LocationSettingsRequest.Builder builder = new LocationSettingsRequest.Builder();
    builder.addLocationRequest(mLocationRequest);
    mLocationSettingsRequest = builder.build();
}

private void createLocationRequest() {
    mLocationRequest = new LocationRequest();
    mLocationRequest.setInterval(FASTEST_UPDATE_INTERVAL_IN_MILLISECONDS);
    mLocationRequest.setFastestInterval(FASTEST_UPDATE_INTERVAL_IN_MILLISECONDS);
    mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
}

我不明白为什么GPS位置波动太大。即使我站着，我也会得到不同的GPS位置。

如何获得准确的GPS定位？

Answer 1

位置波动是正常行为。问题是，何时/如何接受或丢弃意外的位置。正如用户（Patrick Artner）评论的那样，你应该抛弃突然的侧移。

您可以通过两种方式放弃这些动作，

让我们决定最低标准（1米）。

假设最小距离为1米，因为在人类“行走（不站立）”的情况下，人类可以在'X'秒内至少覆盖1米的距离。因此，如果覆盖的距离小于1米，您可以简单地丢弃。
让我们确定最高标准（5米）。

假设最大距离为5米，因为如果人类“行走（不跑步）”，这是不可能的，人类可以在'X'秒内覆盖超过5米的距离。因此，如果覆盖的距离超过5米，您可以简单地丢弃。

其中，

距离= NEW_LOCATION - OLD_LOCATION（How to get distance?）

X =一定的时间（以秒为单位）

只接受小于5米且超过1米的位置（根据您的理解，您可以选择的距离范围）。

Answer 2

描述了GPS系统错误的基础知识，例如here。使用Extended Kalman Filter融合来自GPS的数据（恕我直言，未过滤，从GpsStatus.NmeaListener / OnNmeaMessageListener收到的GPS数据）和其他传感器（加速度计，陀螺仪，磁力计等）可以改善准确性，但今天没有可能创建具有所述功能的良好应用程序（轨道路径大约100米＆＃34;复杂＆＃34;图）。如果你简化路径（如图所示）

并跟踪交叉检查站＆＃34;地理围栏＆＃34;它的顺序 - 可能是你可以实现功能，但在许多情况下准确性是不可接受的。

Answer 3

没有获得精确的GPS坐标是很常见的，因为它取决于许多因素，如

开阔天空或室内条件
像云，建筑物这样的障碍
设备/ CPU电源上的GPS芯片配置
蜂窝网络信号强度

你可以做一些解决方法

使用@ andrii-omelchenko建议的卡尔曼滤波算法
或者你可以使用geofencing机制并设置地理围栏，而android系统将为你提供进入/退出地理围栏的回调
- A）设置几个地理围栏圈（下一组lat长度可能为3~5）
- B）在输入地理围栏时将步骤标记为完成
- C）重复 A，直到用户满意为止
使用Android activity recognition以及上述地理围栏逻辑检查用户是否行走。

下面是示例地理围栏图片，为您提供一个想法

Answer 4

是的gps位置波动是正常的，但如果你想要更准确的做一件事。在这里，我告诉你我的伎俩。

我确定你也做同样的事情。只是告诉你我的方式。

步骤1.制作此课程 GoogleLocationService.java

public class GoogleLocationService { private GoogleServicesCallbacks callbacks = new GoogleServicesCallbacks(); LocationUpdateListener locationUpdateListener; Context activity; protected GoogleApiClient mGoogleApiClient; protected LocationRequest mLocationRequest; public static final long UPDATE_INTERVAL_IN_MILLISECONDS = 2000; public GoogleLocationService(Context activity, LocationUpdateListener locationUpdateListener) { this.locationUpdateListener = locationUpdateListener; this.activity = activity; buildGoogleApiClient(); } protected synchronized void buildGoogleApiClient() { //Log.i(TAG, "Building GoogleApiClient"); mGoogleApiClient = new GoogleApiClient.Builder(activity) .addConnectionCallbacks(callbacks) .addOnConnectionFailedListener(callbacks) .addApi(LocationServices.API) .build(); createLocationRequest(); mGoogleApiClient.connect(); } protected void createLocationRequest() { mLocationRequest = new LocationRequest(); mLocationRequest.setInterval(UPDATE_INTERVAL_IN_MILLISECONDS); mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY); } private class GoogleServicesCallbacks implements GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener, LocationListener { @Override public void onConnected(Bundle bundle) { startLocationUpdates(); } @Override public void onConnectionSuspended(int i) { mGoogleApiClient.connect(); } @Override public void onConnectionFailed(@NonNull ConnectionResult connectionResult) { if (connectionResult.getErrorCode() == ConnectionResult.SERVICE_VERSION_UPDATE_REQUIRED) { Toast.makeText(activity, "Google play service not updated", Toast.LENGTH_LONG).show(); } locationUpdateListener.cannotReceiveLocationUpdates(); } @Override public void onLocationChanged(Location location) { if (location.hasAccuracy()) { if (location.getAccuracy() < 30) { locationUpdateListener.updateLocation(location); } } } } private static boolean locationEnabled(Context context) { boolean gps_enabled = false; LocationManager lm = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE); try { gps_enabled = lm.isProviderEnabled(LocationManager.GPS_PROVIDER); } catch (Exception ex) { ex.printStackTrace(); } return gps_enabled; } private boolean servicesConnected(Context context) { return isPackageInstalled(GooglePlayServicesUtil.GOOGLE_PLAY_STORE_PACKAGE, context); } private boolean isPackageInstalled(String packagename, Context context) { PackageManager pm = context.getPackageManager(); try { pm.getPackageInfo(packagename, PackageManager.GET_ACTIVITIES); return true; } catch (PackageManager.NameNotFoundException e) { e.printStackTrace(); return false; } } public void startUpdates() { /* * Connect the client. Don't re-start any requests here; instead, wait * for onResume() */ if (servicesConnected(activity)) { if (locationEnabled(activity)) { locationUpdateListener.canReceiveLocationUpdates(); startLocationUpdates(); } else { locationUpdateListener.cannotReceiveLocationUpdates(); Toast.makeText(activity, "Unable to get your location.Please turn on your device Gps", Toast.LENGTH_LONG).show(); } } else { locationUpdateListener.cannotReceiveLocationUpdates(); Toast.makeText(activity, "Google play service not available", Toast.LENGTH_LONG).show(); } } //stop location updates public void stopUpdates() { stopLocationUpdates(); } //start location updates private void startLocationUpdates() { if (checkSelfPermission(activity, ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && checkSelfPermission(activity, ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) { return; } if (mGoogleApiClient.isConnected()) { LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, callbacks); } } public void stopLocationUpdates() { if (mGoogleApiClient.isConnected()) { LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, callbacks); } } public void startGoogleApi() { mGoogleApiClient.connect(); } public void closeGoogleApi() { mGoogleApiClient.disconnect(); } }

<强>第二步。制作这个界面 LocationUpdateListener.java

public interface LocationUpdateListener { /** * Called immediately the service starts if the service can obtain location */ void canReceiveLocationUpdates(); /** * Called immediately the service tries to start if it cannot obtain location - eg the user has disabled wireless and */ void cannotReceiveLocationUpdates(); /** * Called whenever the location has changed (at least non-trivially) * @param location */ void updateLocation(Location location); /** * Called when GoogleLocationServices detects that the device has moved to a new location. * @param localityName The name of the locality (somewhere below street but above area). */ void updateLocationName(String localityName, Location location); }

您可以直接在类中需要更新位置的代码下面调用并删除locationservice。

private GoogleLocationService googleLocationService; googleLocationService = new GoogleLocationService(context, new LocationUpdateListener() { @Override public void canReceiveLocationUpdates() { } @Override public void cannotReceiveLocationUpdates() { } //update location to our servers for tracking purpose @Override public void updateLocation(Location location) { if (location != null ) { Timber.e("updated location %1$s %2$s", location.getLatitude(), location.getLongitude()); } } @Override public void updateLocationName(String localityName, Location location) { googleLocationService.stopLocationUpdates(); } }); googleLocationService.startUpdates(); and call this onDestroy if (googleLocationService != null) { googleLocationService.stopLocationUpdates(); }

如果你看，我做了一件事。 getAccuracy（）描述以米为单位的偏差。因此，数字越小，准确度越高。

public void onLocationChanged(Location location) { if (location.hasAccuracy()) { if (location.getAccuracy() < 30) { locationUpdateListener.updateLocation(location); } } }

谢谢希望这对你有所帮助。

GPS位置波动

4 个答案: