如何使用设备的加速度计检测运动增加然后突然停止？
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【中文标题】如何使用设备的加速度计检测运动增加然后突然停止？【英文标题】：How do I detect an increase in movement then a sudden stop using the device's accelerometer? 【发布时间】：2019-01-05 13:22:11 【问题描述】：我正在尝试检测两部手机相互碰撞时会产生的动作。
我的问题是，加速度计是否适合这个传感器？
如果是这样，我将如何实现它？
否则，我应该使用什么传感器以及我应该以什么方式使用它？
根据https://developer.android.com/guide/topics/sensors/sensors_overview 的指南，TYPE_LINEAR_ACCELERATION 似乎适合使用，但我不知道如何使用它。
【问题讨论】：
【参考方案1】：你可以这样做。
1- 像这样初始化传感器对象并注册传感器更新事件回调
private void initSensorObject()
SensorManager sensorMgr = (SensorManager) getSystemService(SENSOR_SERVICE);
Sensor _Sensor = sensorMgr.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
sensorMgr.registerListener(sensorEventListener, _Sensor,
SensorManager.SENSOR_DELAY_FASTEST);
2- 以下列方式处理传感器回调，检测线性加速度，排除重力的影响，然后突然停止运动（我为两个点击运动编写了这个，比如点击然后停止，再次点击然后再次停止。我将解释整个过程以便更好地理解，您可以轻松地对其进行修改以进行一次点击检测。）我在代码中添加了 cmets 以使其不言自明。
/*
* Following are the parameters for Tap detection Algorithm
*/
private static float SPEED_THRESHOLD_RISE1;
private static float SPEED_THRESHOLD_DROP1;
private static float SPEED_THRESHOLD_RISE2;
private static float SPEED_THRESHOLD_DROP2;
private static int DROP_DELTA;
private static int RISE2_DELTA;
private int SENSITIVITY_INDEX = TapParam.SEN_DEFAULT;
private static final int TAP_STATE_RISE1 = 0;
private static final int TAP_STATE_DROP1 = 1;
private static final int TAP_STATE_RISE2 = 2;
private static final int TAP_STATE_DROP2 = 3;
private int tappingState = TAP_STATE_RISE1;
private boolean tapLastStateOnce = false;
private long lastSensorUpdate;
private long tap1DroppedAt = 0;
private int mathMeanIndex = 0;
private float[] lastLinearAcc = new float[3];
private float[] acceleSet = new float[TapParam.AM_SIZE];
private int acceleIndex = 0;
private float[] gravity = new float[3];
private float lastAccele = -99; // an arbitrarily very small value
/**
* onSensorChanged is called when the Motion Sensor value
* is changed and then run the algorithm to detect your desired motion.
*
* @return void
*/
private SensorEventListener sensorEventListener = new SensorEventListener()
@Override
public void onSensorChanged(SensorEvent event)
long curSensorTime = System.currentTimeMillis();
if ((curSensorTime - lastSensorUpdate) < TapParam.SENSOR_RE_READ_TIME)
return;
lastSensorUpdate = curSensorTime;
acceleSet[acceleIndex] = getMotionAcceleration(event, curSensorTime);
acceleIndex = (acceleIndex + 1) % TapParam.AM_SIZE;
if (mathMeanIndex < TapParam.AM_SIZE)
mathMeanIndex++;
float accele = Util.getArithmeticMean(acceleSet);
switch (tappingState)
case TAP_STATE_RISE1:
if (accele > SPEED_THRESHOLD_RISE1)
tappingState = TAP_STATE_DROP1;
resetTapStateDropping();
mathMeanIndex = 0;
break;
case TAP_STATE_DROP1:
if (accele <= SPEED_THRESHOLD_DROP1)
tappingState = TAP_STATE_RISE2;
resetTapStateRise2();
tap1DroppedAt = curSensorTime;
mathMeanIndex = 0;
break;
case TAP_STATE_RISE2:
if (curSensorTime - tap1DroppedAt >= TapParam.DELAY_BETWEEN_TAPS)
if (accele > SPEED_THRESHOLD_RISE2)
tappingState = TAP_STATE_DROP2;
resetTapStateDropping();
mathMeanIndex = 0;
break;
case TAP_STATE_DROP2:
if ((!tapLastStateOnce) && (accele <= SPEED_THRESHOLD_DROP2))
tapLastStateOnce = true;
resetTapStateRise2();
mathMeanIndex = 0;
onTapTapDetected();
break;
default:
tappingState = TAP_STATE_RISE1;
break;
/**
* onAccuracyChanged inter shall be called when hardware IMU
* (Inertial Measurement Unit a.k.a Motion Sensor) of the device change
* its accuracy value.
*
* @return void
*/
@Override
public void onAccuracyChanged(Sensor sensor, int accuracy)
setThresholdValues();
;
/**
* It shall return the Linear Acceleration of the device. The force of
* gravity shall be filtered out.
*
* @return float - Linear acceleration
*/
private float getMotionAcceleration(SensorEvent event, long curSensorTime)
// In this code, alpha is calculated as t / (t + dT),
// where t is the low-pass filter's time-constant and
// dT is the event delivery rate.
final float alpha = 0.8f;
float[] linearAcc = new float[3];
// 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];
// Remove the gravity contribution with the high-pass filter.
linearAcc[0] = event.values[0] - gravity[0];
linearAcc[1] = event.values[1] - gravity[1];
linearAcc[2] = event.values[2] - gravity[2];
float accele = (Math.abs(lastLinearAcc[0] - linearAcc[0])
+ Math.abs(lastLinearAcc[1] - linearAcc[1]) + Math
.abs(lastLinearAcc[2] - linearAcc[2])) / 3;
lastLinearAcc = linearAcc;
return accele;
/**
* resetTapStateRise2 shall reset the tapping state if
* second Tap is not detected within TAP_RISE2_TIME time.
*
* @return void
*/
private void resetTapStateRise2()
handleResetTapState.removeCallbacks(runResetTapState);
handleResetTapState.postDelayed(runResetTapState, RISE2_DELTA);
private Handler handleResetTapState = new Handler();
private Runnable runResetTapState = new Runnable()
@Override
public void run()
tappingState = TAP_STATE_RISE1;
tapLastStateOnce = false;
;
/**
* resetTapStateDropping shall reset the tapping state if
* Tap Drop is not detected within TAP_DROP_TIME time.
*
* @return void
*/
private void resetTapStateDropping()
handleResetTapState.removeCallbacks(runResetTapState);
handleResetTapState.postDelayed(runResetTapState, DROP_DELTA);
private Handler handleResetTapState = new Handler();
private Runnable runResetTapState = new Runnable()
@Override
public void run()
tappingState = TAP_STATE_RISE1;
tapLastStateOnce = false;
;
3- 这是一个帮助您入门的工作参数文件。 thresholds 数组定义了 10 个级别的敏感度，即您想要轻按手机以被检测为有效动作的力度或程度
TapParam.java
final class TapParam
static final int SEN_DEFAULT = 4;
static final int SEN_MIN = 0;
static final int SEN_MAX = 9;
static final int DELAY_BETWEEN_TAPS = 75;
static final int SENSOR_RE_READ_TIME = 1;
static final int AM_SIZE = 5;
// Columns: A B Y D T1 T2 T3
private static final double[][] thresholds = new double[][]
0.8483763, 0.33935052, 0.5655842, 0.33935052, 175, 300, 175,
0.95167595, 0.38067037, 0.6344506, 0.38067037, 175, 300, 175,
1.0836192, 0.4334477, 0.7224128, 0.4334477, 175, 300, 175,
1.8552876, 0.742115, 1.2368584, 0.742115, 175, 300, 175,
2.4327612, 0.9731045, 1.6218408, 0.9731045, 175, 300, 175,
3.5321822, 1.4128729, 2.354788, 1.4128729, 175, 300, 175,
6.4446864, 2.5778747, 4.296458, 2.5778747, 175, 300, 175,
8.2, 3.5, 5.4, 2.6, 175, 300, 175,
9.8, 4.0, 6.0, 2.9, 175, 300, 175,
12, 6.0, 8.0, 3.1, 175, 300, 175
;
private static int indexLimiting(int index)
return (index > SEN_MAX) ? SEN_MAX : (index < SEN_MIN) ? SEN_MIN : index;
static float getRISE1(int index)
index = indexLimiting(index);
return (float) thresholds[index][0];
static float getDROP1(int index)
index = indexLimiting(index);
return (float) thresholds[index][1];
static float getRISE2(int index)
index = indexLimiting(index);
return (float) thresholds[index][2];
static float getDROP2(int index)
index = indexLimiting(index);
return (float) thresholds[index][3];
static float getDROP_DELTA1(int index)
index = indexLimiting(index);
return (float) thresholds[index][4];
static float getRISE_DELTA2(int index)
index = indexLimiting(index);
return (float) thresholds[index][5];
更新：
/**
* setThresholdValues method shall calculate the Threshold values according
* to the accuracy value of the Motion Sensor.
*/
private void setThresholdValues()
if (_Sensor == null)
return;
SPEED_THRESHOLD_RISE1 = TapParam.getRISE1(SENSITIVITY_INDEX);
SPEED_THRESHOLD_DROP1 = TapParam.getDROP1(SENSITIVITY_INDEX);
SPEED_THRESHOLD_RISE2 = TapParam.getRISE2(SENSITIVITY_INDEX);
SPEED_THRESHOLD_DROP2 = TapParam.getDROP2(SENSITIVITY_INDEX);
/**
* Method shall return the average (Arithmetic Mean) of the set of values
* passed as parameter.
*
* @param float[] set - the set of values
* @return float - arithmetic mean
*/
static float getArithmeticMean(float[] set)
double sum = 0;
for (float aSet : set)
sum += aSet;
return (float) sum / set.length;
更新 2：
在您的活动的onCreate() 中致电setTapTapSensitivity()
private void setTapTapSensitivity()
setTapTapSensitivity(3); //You can try 0 to 9 for 10 levels of sensitivity defined in TapParam.java. I have tried 3 and it works for a moderate tap
private void setTapTapSensitivity(int sensitivityIndex)
RISE2_DELTA = (int) TapParam.getRISE_DELTA2(sensitivityIndex);
DROP_DELTA = (int) TapParam.getDROP_DELTA1(sensitivityIndex);
SENSITIVITY_INDEX = sensitivityIndex;
【讨论】：
我没想到你会给我一切，但是谢谢！我马上试试看。getArithmeticMean 和 setThresholdValues 到底应该怎么做？
D'oh，这应该很明显。我会检查它是否有效。
这个好像不行，建议我怎么调试？
有什么问题？这是一个有效的例子。我建议您在Service 中完成所有这些操作以上是关于如何使用设备的加速度计检测运动增加然后突然停止？的主要内容，如果未能解决你的问题，请参考以下文章