准确地读取Android的加速度值

准确地读取Android的加速度值

本文介绍了如何在稳定,准确地读取Android的加速度值?的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

在我的项目,我想控制通过使用Android设备的加速度计获得的数据一辆车。 (左,右,前,反向)。尽管我已成功地从加速计读取值读数变动频繁,即使该设备是在稳定的位置。谁能给我提供一个更好的方式来做到这一点?

以下是code,我是用

 进口android.content.Context;
进口android.hardware.Sensor;
进口android.hardware.SensorEvent;
进口android.hardware.SensorEventListener;
进口android.hardware.SensorManager;

公共类AccelerometerService {
    私有静态的SensorManager的SensorManager;
    私有静态SensorEventListener sensorEventListener;
    私有静态布尔开始= FALSE;

    私有静态浮动[]加速度=新的浮动[3];
    私有静态浮动[] magneticField =新的浮动[3];

    私有静态浮动[] rotationMatrix =新的浮动[9];
    私有静态浮动[] inclinationMatrix =新的浮动[9];
    私有静态浮动[]的态度=新的浮动[3];

    私人最终静态双RAD2DEG = 180 / Math.PI;

    私有静态诠释initialAzimuth = 0;
    私有静态诠释initialPitch = 0;
    私有静态诠释initialRoll = 0;

    私有静态诠释[] attitudeInDegrees =新INT [3];

    公共静态无效的开始(最终上下文的applicationContext){
        如果(开始){
            返回;
        }

        的SensorManager =(的SensorManager)的applicationContext
                .getSystemService(Context.SENSOR_SERVICE);

        sensorEventListener =新SensorEventListener(){

            @覆盖
            公共无效onSensorChanged(SensorEvent事件){

                整型= event.sensor.getType();
                如果(类型== Sensor.TYPE_MAGNETIC_FIELD){
                    magneticField = event.values​​.clone();
                }
                如果(类型== Sensor.TYPE_ACCELEROMETER){
                    加速度= event.values​​.clone();
                }

                SensorManager.getRotationMatrix(rotationMatrix,inclinationMatrix,加速度计,magneticField);
                SensorManager.getOrientation(rotationMatrix,态度);

                attitudeInDegrees [0] =(int)的Math.round(姿态[0] * RAD2DEG); //方位
                attitudeInDegrees [1] =(int)的Math.round(姿态[1] * RAD2DEG); //沥青
                attitudeInDegrees [2] =(int)的Math.round(姿态[2] * RAD2DEG); //滚
            }

            @覆盖
            公共无效onAccuracyChanged(传感器传感器,诠释精度){

            }
        };
        sensorManager.registerListener(sensorEventListener,
                sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER)
                SensorManager.SENSOR_DELAY_UI);
        sensorManager.registerListener(sensorEventListener,
                sensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD)
                SensorManager.SENSOR_DELAY_UI);

        开始= TRUE;
    }

    公共静态布尔getStarted(){
        返回开始;
    }

    公共静态无效停止(){
        如果(开始){
        sensorManager.unregisterListener(sensorEventListener);
        开始= FALSE;
        }
    }
}
 

解决方案

老问题,但我在这里回答为他人着想是找到这个问题的。

首先,以下@安德鲁 - 莫顿链接正是我需要的,但在伪code,所以这里的Java为Android!

二:如果你能(你是最小的API拉特是9或更高版本),只需使用Sensor.TYPE_GRAVITY。因为它已经理顺。如果你需要支持旧的API Lvls(像我不得不),这code应该做的伎俩!

最后:这code段有所修改,从我使用它,如果你想用这个为自己,你需要创建一个getter为Vector3类型的重力是什么

注意:我发现,5(MAX_SAMPLE_SIZE)的滚动平均值是比较顺利的。 10更是顺利,但你开始注意到滞后。

 进口android.hardware.Sensor;
进口android.hardware.SensorEvent;
进口android.hardware.SensorEventListener;
进口android.hardware.SensorManager;
进口的java.util.ArrayList;
进口的java.util.List;

/ **
 *在14年6月14日创建者安迪。
 * /
公共类AndroidGravityUpdate实现SensorEventListener {
    私人的SensorManager的SensorManager;
    Vector3类型的重力;
    名单<浮动> [] rollingAverage =新名单[3];

    私有静态最终诠释MAX_SAMPLE_SIZE = 5;

    AndroidGravityUpdate(的SensorManager的SensorManager){
        this.gravity =新Vector3类型();
        this.sensorManager =的SensorManager;

        如果(sensorManager.getSensorList(Sensor.TYPE_GRAVITY).size()大于0){
            sensorManager.registerListener(
                    本,
                    sensorManager.getDefaultSensor(Sensor.TYPE_GRAVITY)
                    SensorManager.SENSOR_DELAY_GAME
            );
        }否则如果(sensorManager.getSensorList(Sensor.TYPE_ACCELEROMETER).size()大于0){
            rollingAverage [0] =新的ArrayList<浮动>();
            rollingAverage [1] =新的ArrayList&其中;浮法>();
            rollingAverage [2] =新的ArrayList&其中;浮法>();

            sensorManager.registerListener(
                    本,
                    sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER)
                    SensorManager.SENSOR_DELAY_GAME
                );
        }

    }

    @覆盖
    公共无效onSensorChanged(SensorEvent事件){
        如果(event.sensor.getType()== Sensor.TYPE_GRAVITY){
            gravity.z = event.values​​ [0];
            gravity.x = event.values​​ [1];
            gravity.y =  -  event.values​​ [2];
        }
        否则如果(event.sensor.getType()== Sensor.TYPE_ACCELEROMETER){
            //无论出于何种原因,我的三星只有加速度
            //但它是非常粗糙的,因此试图平稳
            //它与滚动平均值。
            rollingAverage [0] =辊(rollingAverage [0],event.values​​ [0]);
            rollingAverage [1] =辊(rollingAverage [1],event.values​​ [1]);
            rollingAverage [2] =辊(rollingAverage [2],-event.values​​ [2]);

            gravity.z = averageList(rollingAverage [0]);
            gravity.x = averageList(rollingAverage [1]);
            gravity.y = averageList(rollingAverage [2]);
        }
    }

    公开名单<浮动>卷(册及LT;浮动>清单,浮动newMember){
        如果(则为list.size()== MAX_SAMPLE_SIZE){
            list.remove(0);
        }
        list.add(newMember);
        返回列表;
    }

    公众持股量averageList(名单<浮动> tallyUp){

        总浮= 0;
        为(浮动项:tallyUp){
            共有+ =项目;
        }
        总=总/ tallyUp.size();

        总回报;
    }

    @覆盖
    公共无效onAccuracyChanged(传感器传感器,诠释精度){

    }
}

一流的Vector3类型{
    浮动X;
    浮动Ÿ;
    浮动ž;
}
 

In a my project I am trying to control a car using data obtained through the accelerometer of an Android device. (Left, Right, Forward, Reverse). Even though I have managed to read values from the accelerometer the readings are subject to frequent changes even the device is in a stable position. Can someone provide me a better way to do this?

Following is the code that I have used

import android.content.Context;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;

public class AccelerometerService {
    private static SensorManager sensorManager;
    private static SensorEventListener sensorEventListener;
    private static boolean started = false;

    private static float[] accelerometer = new float[3];
    private static float[] magneticField = new float[3];

    private static float[] rotationMatrix = new float[9];
    private static float[] inclinationMatrix = new float[9];
    private static float[] attitude = new float[3];

    private final static double RAD2DEG = 180/Math.PI;

    private static int initialAzimuth = 0;
    private static int initialPitch = 0;
    private static int initialRoll = 0;

    private static int[] attitudeInDegrees = new int[3];

    public static void start(final Context applicationContext) {
        if(started) {
            return;
        }

        sensorManager = (SensorManager) applicationContext
                .getSystemService(Context.SENSOR_SERVICE);

        sensorEventListener = new SensorEventListener() {

            @Override
            public void onSensorChanged(SensorEvent event) {

                int type = event.sensor.getType();
                if(type == Sensor.TYPE_MAGNETIC_FIELD) {
                    magneticField = event.values.clone();
                }
                if(type == Sensor.TYPE_ACCELEROMETER) {
                    accelerometer = event.values.clone();
                }

                SensorManager.getRotationMatrix(rotationMatrix, inclinationMatrix, accelerometer, magneticField);
                SensorManager.getOrientation(rotationMatrix, attitude);

                attitudeInDegrees[0] =  (int) Math.round(attitude[0] * RAD2DEG);    //azimuth
                attitudeInDegrees[1] = (int) Math.round(attitude[1] * RAD2DEG);     //pitch
                attitudeInDegrees[2] = (int) Math.round(attitude[2] * RAD2DEG);     //roll
            }

            @Override
            public void onAccuracyChanged(Sensor sensor, int accuracy) {

            }
        };
        sensorManager.registerListener(sensorEventListener,
                sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER),
                SensorManager.SENSOR_DELAY_UI);
        sensorManager.registerListener(sensorEventListener,
                sensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD),
                SensorManager.SENSOR_DELAY_UI);

        started = true;
    }

    public static boolean getStarted() {
        return started;
    }

    public static void stop() {
        if(started) {
        sensorManager.unregisterListener(sensorEventListener);
        started = false;
        }
    }
}
解决方案

Old question, but I'm answering here for the sake of others that find this question.

First off, following @andrew-morton link is exactly what I needed, but was in pseudo code, so here is Java for Android!

Second: If you can (you're min API Lvl is 9 or higher), simply use the Sensor.TYPE_GRAVITY. As it is already smoothed out. If you need to support older API Lvls (like I had to), this code should do the trick!

Lastly: This code snippet is somewhat modified from what I am using it for, if you want to use this for yourself, you'll need to create a getter for the Vector3 gravity.

Notes:I've found that a rolling average of 5 (MAX_SAMPLE_SIZE) is quite smooth. 10 is even more smooth, but you start to notice lag.

import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import java.util.ArrayList;
import java.util.List;

/**
 * Created by andy on 6/14/14.
 */
public class AndroidGravityUpdate implements SensorEventListener {
    private SensorManager sensorManager;
    Vector3 gravity;
    List<Float>[] rollingAverage = new List[3];

    private static final int MAX_SAMPLE_SIZE = 5;

    AndroidGravityUpdate( SensorManager sensorManager ) {
        this.gravity = new Vector3();
        this.sensorManager = sensorManager;

        if(sensorManager.getSensorList(Sensor.TYPE_GRAVITY).size() > 0){
            sensorManager.registerListener(
                    this,
                    sensorManager.getDefaultSensor(Sensor.TYPE_GRAVITY),
                    SensorManager.SENSOR_DELAY_GAME
            );
        } else if( sensorManager.getSensorList(Sensor.TYPE_ACCELEROMETER).size() > 0) {
            rollingAverage[0] = new ArrayList<Float>();
            rollingAverage[1] = new ArrayList<Float>();
            rollingAverage[2] = new ArrayList<Float>();

            sensorManager.registerListener(
                    this,
                    sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER),
                    SensorManager.SENSOR_DELAY_GAME
                );
        }

    }

    @Override
    public void onSensorChanged(SensorEvent event) {
        if (event.sensor.getType()==Sensor.TYPE_GRAVITY){
            gravity.z = event.values[0];
            gravity.x = event.values[1];
            gravity.y = - event.values[2];
        }
        else if ( event.sensor.getType()==Sensor.TYPE_ACCELEROMETER) {
            //For whatever reason, my Samsung only has "Accelerometer"
            // But it is incredibly rough, so attempting to smooth
            // it out with rolling averages.
            rollingAverage[0] = roll(rollingAverage[0], event.values[0]);
            rollingAverage[1] = roll(rollingAverage[1], event.values[1]);
            rollingAverage[2] = roll(rollingAverage[2], -event.values[2]);

            gravity.z = averageList(rollingAverage[0]);
            gravity.x = averageList(rollingAverage[1]);
            gravity.y = averageList(rollingAverage[2]);
        }
    }

    public List<Float> roll(List<Float> list, float newMember){
        if(list.size() == MAX_SAMPLE_SIZE){
            list.remove(0);
        }
        list.add(newMember);
        return list;
    }

    public float averageList(List<Float> tallyUp){

        float total=0;
        for(float item : tallyUp ){
            total+=item;
        }
        total = total/tallyUp.size();

        return total;
    }

    @Override
    public void onAccuracyChanged(Sensor sensor, int accuracy) {

    }
}

class Vector3 {
    float x;
    float y;
    float z;
}

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09-06 05:28