lejos.localization
Class ParticleSet

java.lang.Object
  lejos.localization.ParticleSet

public class ParticleSet
extends Object

Represents a particle set for the particle filtering algorithm.

Author:

Lawrie Griffiths

WARNING: THIS CLASS IS SHARED BETWEEN THE classes AND pccomms PROJECTS. DO NOT EDIT THE VERSION IN pccomms AS IT WILL BE OVERWRITTEN WHEN THE PROJECT IS BUILT.

Field Summary

static float	angleNoiseFactor
static int	border
static float	distanceNoiseFactor
static int	forwardReading
static int	maxIterations
static int	numReadings
static int	rangeReadingAngle
static float[]	readings
static float	twoSigmaSquared

Constructor Summary

ParticleSet(Map map, int numParticles)
Create a set of particles randomly distributed with the given map.

Method Summary

void	applyMove(Move move) Apply a move to each particle
void	calculateWeights(RangeReadings rr, Map map) Calculate the weight for each particle
void	dumpClosest(DataOutputStream dos, float x, float y) Find the closest particle to specified coordinates and dump its details to a data output stream.
void	dumpEstimation(DataOutputStream dos) Dump the serialized estimate of pose to a data output stream
void	dumpParticles(DataOutputStream dos) Serialize the particle set to a data output stream
int	findClosest(float x, float y) Find the index of the particle closest to a given co-ordinates
Pose	getEstimatedPose() Get the estimated pose of the robot
float	getMaxWeight() The highest weight of any particle
float	getMaxX() Get the maximum X value of the estimated position
float	getMaxY() Get the maximum Y value of the estimated position
float	getMinX() Get the minimum X value of the estimated position
float	getMinY() Get the minimum Y value of the estimated position
Particle	getParticle(int i) Get a specific particle
void	loadEstimation(DataInputStream dis) Load serialized estimated pose from a data input stream
void	loadParticles(DataInputStream dis) Load serialized particles from a data input stream
int	numParticles() Return the number of particles in the set
boolean	resample() Resample the set picking those with higher weights.
void	resetEstimate() Reset the estimated position to unknown
static void	setAngleNoiseFactor(float factor) Set the distance angle factor
static void	setBorder(int border) Set border
static void	setDistanceNoiseFactor(float factor) Set the distance noise factor
static void	setForwardReading(int index) Set the index of the reading that is straight ahead
static void	setMaxIterations(int max) Set the maximum iterations for the resample algorithm
static void	setNumReadings(int num) Set the number of range readings
static void	setRangeReadingAngle(int angle) Set the range reading angle
static void	setSigma(float sigma) Set the standard deviation for the sensor probability model

Methods inherited from class java.lang.Object

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

Field Detail

maxIterations

public static int maxIterations

twoSigmaSquared

public static float twoSigmaSquared

distanceNoiseFactor

public static float distanceNoiseFactor

angleNoiseFactor

public static float angleNoiseFactor

numReadings

public static int numReadings

rangeReadingAngle

public static int rangeReadingAngle

forwardReading

public static int forwardReading

border

public static int border

readings

public static float[] readings

Constructor Detail

ParticleSet

public ParticleSet(Map map,
                   int numParticles)

Create a set of particles randomly distributed with the given map.

Parameters:

map - the map of the enclosed environment

Method Detail

numParticles

public int numParticles()

Return the number of particles in the set

Returns:

the number of particles

getParticle

public Particle getParticle(int i)

Get a specific particle

Parameters:

i - the index of the particle

Returns:

the particle

resample

public boolean resample()

Resample the set picking those with higher weights. Note that the new set has multiple instances of the particles with higher weights.

Returns:

true iff lost

calculateWeights

public void calculateWeights(RangeReadings rr,
                             Map map)

Calculate the weight for each particle

Parameters:

rr - the robot range readings

applyMove

public void applyMove(Move move)

Apply a move to each particle

Parameters:

move - the move to apply

getEstimatedPose

public Pose getEstimatedPose()

Get the estimated pose of the robot

Returns:

the estimated pose

getMinX

public float getMinX()

Get the minimum X value of the estimated position

Returns:

the minimum X value

getMaxX

public float getMaxX()

Get the maximum X value of the estimated position

Returns:

the maximum X value

getMinY

public float getMinY()

Get the minimum Y value of the estimated position

Returns:

the minimum Y value

getMaxY

public float getMaxY()

Get the maximum Y value of the estimated position

Returns:

the maximum Y value

resetEstimate

public void resetEstimate()

Reset the estimated position to unknown

getMaxWeight

public float getMaxWeight()

The highest weight of any particle

Returns:

the highest weight

setBorder

public static void setBorder(int border)

Set border

Parameters:

border - the border where no particles should be generated

setSigma

public static void setSigma(float sigma)

Set the standard deviation for the sensor probability model

Parameters:

sigma - the standard deviation

setDistanceNoiseFactor

public static void setDistanceNoiseFactor(float factor)

Set the distance noise factor

Parameters:

factor - the distance noise factor

setAngleNoiseFactor

public static void setAngleNoiseFactor(float factor)

Set the distance angle factor

Parameters:

factor - the distance angle factor

setRangeReadingAngle

public static void setRangeReadingAngle(int angle)

Set the range reading angle

Parameters:

angle - the angle between range readings

setForwardReading

public static void setForwardReading(int index)

Set the index of the reading that is straight ahead

Parameters:

index - the forward reading index

setNumReadings

public static void setNumReadings(int num)

Set the number of range readings

Parameters:

num - the number of range readings

setMaxIterations

public static void setMaxIterations(int max)

Set the maximum iterations for the resample algorithm

Parameters:

max - the maximum iterations

findClosest

public int findClosest(float x,
                       float y)

Find the index of the particle closest to a given co-ordinates

Parameters:

x - the x-coordinate

y - the y-coordinate

Returns:

the index

dumpParticles

public void dumpParticles(DataOutputStream dos)
                   throws IOException

Serialize the particle set to a data output stream

Parameters:

dos - the data output stream

Throws:

IOException

loadParticles

public void loadParticles(DataInputStream dis)
                   throws IOException

Load serialized particles from a data input stream

Parameters:

dis - the data input stream

Throws:

IOException

dumpEstimation

public void dumpEstimation(DataOutputStream dos)
                    throws IOException

Dump the serialized estimate of pose to a data output stream

Parameters:

dos - the data output stream

Throws:

IOException

loadEstimation

public void loadEstimation(DataInputStream dis)
                    throws IOException

Load serialized estimated pose from a data input stream

Parameters:

dis - the data imput stream

Throws:

IOException

dumpClosest

public void dumpClosest(DataOutputStream dos,
                        float x,
                        float y)
                 throws IOException

Find the closest particle to specified coordinates and dump its details to a data output stream.

Parameters:

dos - the data output stream

x - the x-coordinate

y - the y-coordinate

Throws:

IOException