Question

我试图写一个小应用程序，用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入屏幕。问题是移动手机后速度不会回到零速度。它会在速度的最高点稳定下来。我使用的是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

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

Accelerometer

        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) {

Answer 2

private void calculateVelocity(float x, float y, float z){
    long now = System.currentTimeMillis();
    interval = (now - lastEvent);
    if(interval > 100){
        lastEvent = now;
        double acceleration = x+y+z-lastX-lastY-lastZ;
        double velocity = v0 + (acceleration*(interval/(double)1000));
        velocities.add(Math.abs(velocity));
        v0= velocity;
        lastX = x;
        lastY = y;
        lastZ = z;
    }
}

这是我用来计算每100毫秒速度的代码。 velocities-array用于计算每秒的平均速度，您可以忽略它。该方法的输入是event.values

使用机器人加速度计确定恒定速度

2 个答案: