Package lejos.robotics.localization

Class MCLParticle

java.lang.Object

lejos.robotics.localization.MCLParticle

public class MCLParticle
extends java.lang.Object

Represents a particle for the particle filtering algorithm. The state of the particle is the pose, which represents a possible pose of the robot. The weight for a particle is set by taking a set of theoretical range readings using a map of the environment, and comparing these ranges with those taken by the robot. The weight represents the relative probability that the robot has this pose. Weights are from 0 to 1.

Field Summary

Fields

Modifier and Type	Field and Description
private static boolean	debug
private Pose	pose
private static java.util.Random	rand
private float	weight

Constructor Summary

Constructors

Constructor and Description
MCLParticle(Pose pose) Create a particle with a specific pose

Method Summary

Modifier and Type	Method and Description
void	applyMove(Move move, float distanceNoiseFactor, float angleNoiseFactor) Apply the robot's move to the particle with a bit of random noise.
void	calculateWeight(RangeReadings rr, RangeMap map, float divisor) Calculate the weight for this particle by comparing its readings with the robot's readings
Pose	getPose() Return the pose of this particle
float	getReading(int i, RangeReadings rr, RangeMap map) Get a specific reading
RangeReadings	getReadings(RangeReadings rr, RangeMap map)
float	getWeight() Return the weight of this particle
static void	setDebug(boolean yes)
void	setWeight(float weight) Set the weight for this particle

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

rand

private static java.util.Random rand

pose

private Pose pose

weight

private float weight

debug

private static boolean debug

Constructor Detail

MCLParticle

public MCLParticle(Pose pose)

Create a particle with a specific pose

Parameters:

pose - the pose

Method Detail

setDebug

public static void setDebug(boolean yes)

setWeight

public void setWeight(float weight)

Set the weight for this particle

Parameters:

weight - the weight of this particle

getWeight

public float getWeight()

Return the weight of this particle

Returns:

the weight

getPose

public Pose getPose()

Return the pose of this particle

Returns:

the pose

calculateWeight

public void calculateWeight(RangeReadings rr,
                            RangeMap map,
                            float divisor)

Calculate the weight for this particle by comparing its readings with the robot's readings

Parameters:

rr - Robot readings

getReading

public float getReading(int i,
                        RangeReadings rr,
                        RangeMap map)

Get a specific reading

Parameters:

i - the index of the reading

Returns:

the reading

getReadings

public RangeReadings getReadings(RangeReadings rr,
                                 RangeMap map)

applyMove

public void applyMove(Move move,
                      float distanceNoiseFactor,
                      float angleNoiseFactor)

Apply the robot's move to the particle with a bit of random noise. Only works for rotate or travel movements.

Parameters:

move - the robot's move