java - 使用 Android 加速度计确定恒定速度

Question

我正在尝试编写一个小应用程序，它可以根据手机的速度更新屏幕。它使用加速度计计算当前速度并将其写在屏幕上。问题是移动手机后速度不会回到零速度。它将稳定在速度的最高点。我正在使用 LINEAR_ACCELEROMETER

这是代码:

public class AccelerometerUpSensor extends SensorAbstract{
private ExerciseFragment fragment;
private double v0 = 0;
private float lastX;
private float lastY;
private float lastZ;
private long interval;
private long lastEvent = System.currentTimeMillis();
public AccelerometerUpSensor(SensorManager sensorManager, ExerciseFragment fragment, int[] sensorTypes){
    super(sensorManager,sensorTypes);
    this.fragment = fragment;
}
@Override
public final void onSensorChanged(SensorEvent event) {
    lastX = event.values[0];
    lastY = event.values[1];
    lastZ = event.values[2];
    long now = System.currentTimeMillis();
    interval = (now - lastEvent);
    lastEvent = now;
    double acceleration = lastX+lastY+lastZ;
    double velocity = v0 + (acceleration*(interval/(double)1000));
    v0 = velocity;
    System.out.println(velocity);
}

Answer 1

1. 有 com.google.android.gms ActivityRecognition，您可以在其中跟踪不同类型的移动。

2. 加速度计

           mGravity = event.values.clone();
   
           float x = mGravity[0];
           float y = mGravity[1];
           float z = mGravity[2];
           mAccelLast = mAccelCurrent;
           mAccelCurrent =(float) Math.sqrt(x * x + y * y + z * z);
           float delta = mAccelCurrent - mAccelLast;
           mAccel = mAccel * 0.9f + delta;
   
   
           // Make this higher or lower according to how much motion you want to detect
           if (Math.abs(mAccel) > 2) {