android - 在 Android 中使用加速度计准确检测运动

Question

我正在实现一个带有振动(在特定条件下)的演示定时器，当我按下开始时，我的定时器开始运行。当我使用停止按钮停止它时，它就停止了。

现在我必须集成一个功能，当人移动设备时(当计时器正在运行时)，它应该重置计时器。它工作得很好，但加速度计功能并不是绝对准确。它需要一个快速的 Action 来重置计时器。

建议我一个好的解决方案。

这是我的代码

public class SensorAccelerometer implements SensorEventListener {

    private Context context;
    private SensorManager sensorManager;
    private Sensor accelerometer;
    private TextView timelabel;
    private Handler mHandler;
    Runnable run;

    private float mLastX, mLastY, mLastZ;
    private final float NOISE = (float) 3.0;

    public SensorAccelerometer(Context context) {

    }


    public SensorAccelerometer(Context context,TextView timelabel, Handler mHandler2, Runnable mUpdateTimeTask) {
        // TODO Auto-generated constructor stub

        this.context = context;
        this.timelabel = timelabel;
        this.mHandler = mHandler2;
        this.run = mUpdateTimeTask;

        initialiseSensor();
    }


    public void initialiseSensor(){
        sensorManager = (SensorManager)context.getSystemService(Context.SENSOR_SERVICE);
        accelerometer = sensorManager.getDefaultSensor(Sensor.TYPE_ALL);
        sensorManager.registerListener(this, accelerometer,SensorManager.SENSOR_DELAY_NORMAL);
    }

    public void unregisterSensor(){
        sensorManager.unregisterListener(this);
        Toast.makeText(context, "Sensor Stopped..", Toast.LENGTH_SHORT).show();
    }


    public void onAccuracyChanged(Sensor sensor, int accuracy) {

    }

    public void onSensorChanged(SensorEvent event) {
    float x = event.values[0];
    float y = event.values[1];
    float z = event.values[2];

    mAccelLast=mAccelCurrent;

    mAccelCurrent = FloatMath.sqrt(x*x + y*y + z*z);
    float delta = mAccelCurrent - mAccelLast;
    mAccel = mAccel * 0.9f + delta;

    if(mAccel>0.5){
        TimerActivity.mStartTime = SystemClock.uptimeMillis();
        mHandler.removeCallbacks(run);
        mHandler.postDelayed(run, 100);
    }

计时器 Activity

public class TimerActivity extends Activity {

    public static long mStartTime = 0L;
    private TextView mTimerLabel;

    private Handler mHandler = new Handler();

    String timerStop1;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        mTimerLabel = (TextView) findViewById(R.id.textTimer);

        Button timerStartButton = (Button) findViewById(R.id.btnTimer);       
        timerStartButton.setOnClickListener(new View.OnClickListener() {
            public void onClick(View view){

                if(mStartTime == 0L){
                    mStartTime = SystemClock.uptimeMillis();
                    mHandler.removeCallbacks(mUpdateTimeTask);
                    mHandler.postDelayed(mUpdateTimeTask, 100);

                    //activating the sensor and the acclerometer
                    SensorAccelerometer acc = new SensorAccelerometer(view.getContext(), mTimerLabel,mHandler,mUpdateTimeTask);
                }                                   
            }
        }); 

        Button timerStopButton = (Button) findViewById(R.id.btnTimerStop);       
        timerStopButton.setOnClickListener(new View.OnClickListener() {
            public void onClick(View view){

                mHandler.removeCallbacks(mUpdateTimeTask);
                mTimerLabel.setText(timerStop1);
                mStartTime = 0L;

                SensorAccelerometer scc = new SensorAccelerometer(view.getContext(),mTimerLabel,mHandler,mUpdateTimeTask);
                scc.unregisterSensor();
            }
        }); 

    } 


    private Runnable mUpdateTimeTask = new Runnable(){

        public void run() {

            final long start = mStartTime;
            long millis = SystemClock.uptimeMillis()- start;

            int seconds = (int) (millis / 1000);
            int minutes = seconds / 60;
            seconds = seconds % 60;

            mTimerLabel.setText("" + minutes + ":"
                                  + String.format("%02d", seconds));                    

            timerStop1 = minutes + ":"
                      + String.format("%02d", seconds);

            mHandler.postDelayed(this, 200);            

        }   
    }; 

    protected void onPause() {
        super.onPause();
        SensorAccelerometer scc = new SensorAccelerometer(this,mTimerLabel,mHandler,mUpdateTimeTask);
        scc.unregisterSensor();
    };

} 

Answer 1

我认为您应用开发的下一阶段是查看电子表格中生成的加速值。我为此使用 Excel，但任何可以生成图表的工具都可以。因此，将 onSensorChanged() 更改为类似

的内容

public void onSensorChanged(SensorEvent event) {
    float x = event.values[0];
    float y = event.values[1];
    float z = event.values[2];

    float mAccelCurrent = FloatMath.sqrt(x*x + y*y + z*z);
    float mAccel = mAccel * 0.9f + mAccelCurrent * 0.1f;
    Log.d("onSensorChanged",System.currentTimeMillis()+","+mAccelCurrent +","+mAccel);

}

然后您可以将 currentTime、mAccelCurrent 和 mAccel 捕获到 Android 日志记录机制中。或者，创建您自己的文本文件，在其中写入值，然后在可以生成图形的工具中打开该文件。然后，您可以根据图表决定要用于触发器的值。