Package lejos.robotics.navigation

Class CompassPilot

java.lang.Object

lejos.robotics.navigation.DifferentialPilot

lejos.robotics.navigation.CompassPilot

All Implemented Interfaces:

ArcMoveController, ArcRotateMoveController, LineFollowingMoveController, MoveController, MoveProvider, RotateMoveController

public class CompassPilot
extends DifferentialPilot

A Pilot that keeps track of direction using a DirectionFinder. This class will disappear in NXJ version 1.0. Compass should be added to a PoseProvider.

See Also:

PoseProvider.getPose()

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
(package private) class	CompassPilot.Regulator inner class to regulate heading during travel move Proportional control of steering ; error is an average of heading change from tacho counts and from compass change

Field Summary

Fields

Modifier and Type	Field and Description
protected byte	_direction
protected float	_distance
protected float	_estimatedHeading
protected float	_heading
protected float	_heading0
protected boolean	_traveling
protected DirectionFinder	compass
protected CompassPilot.Regulator	regulator

Fields inherited from class lejos.robotics.navigation.DifferentialPilot

_left, _leftDegPerDistance, _outside, _right, _rightDegPerDistance, _type

Fields inherited from interface lejos.robotics.navigation.MoveController

WHEEL_SIZE_EV3, WHEEL_SIZE_NXT1, WHEEL_SIZE_NXT2, WHEEL_SIZE_RCX

Constructor Summary

Constructors

Constructor and Description
CompassPilot(DirectionFinder compass, float wheelDiameter, float trackWidth, RegulatedMotor leftMotor, RegulatedMotor rightMotor) Allocates a CompasPilot object, and sets the physical parameters of the NXT robot.
CompassPilot(DirectionFinder compass, float wheelDiameter, float trackWidth, RegulatedMotor leftMotor, RegulatedMotor rightMotor, boolean reverse) Allocates a CompasPilot object, and sets the physical parameters of the NXT robot.

Method Summary

Modifier and Type	Method and Description
void	calibrate() Rotates the robot 360 degrees while calibrating the compass resets compass zero to heading at end of calibration
float	getAngleIncrement() Returns the change in robot heading since the last call of reset() normalized to be within -180 and _180 degrees
DirectionFinder	getCompass() Return the compass
float	getCompassHeading() Method returns the current compass heading
float	getHeading() Returns direction of desired robot facing
float	getHeadingError() Determines the difference between actual compass direction and desired heading in degrees
boolean	isTraveling() returns returns true if the robot is travelling for a specific distance;
protected float	normalize(float angle)
void	reset() Resets tacho count for both motors.
void	resetCartesianZero()
void	rotate(float angle) Rotates the NXT robot through a specific angle; Rotates left if angle is positive, right if negative, Returns when angle is reached.
void	rotate(float angle, boolean immediateReturn) robot rotates to the specified compass heading;
void	setHeading(float angle) sets direction of desired robot facing in degrees
void	stop() Stops the robot soon after the method is executed.
protected void	stopNow()
void	travel(float distance) Moves the NXT robot a specific distance; A positive distance causes forward motion; negative distance moves backward.
void	travel(float distance, boolean immediateReturn) Moves the NXT robot a specific distance.

Methods inherited from class lejos.robotics.navigation.DifferentialPilot

addMoveListener, arc, arc, arcBackward, arcForward, backward, forward, getAngularAcceleration, getAngularSpeed, getLinearAcceleration, getLinearSpeed, getMaxAngularSpeed, getMaxLinearSpeed, getMaxRotateSpeed, getMinRadius, getMovement, getMovementIncrement, getTurnRate, isMoving, isStalled, movementActive, movementStart, quickStop, rotate, rotate, rotateLeft, rotateRight, setAngularAcceleration, setAngularSpeed, setLinearAcceleration, setLinearSpeed, setMinRadius, steer, steer, steer, steerBackward, steerPrep, travel, travel, travelArc, travelArc

Methods inherited from class java.lang.Object

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

Field Detail

compass

protected DirectionFinder compass

regulator

protected CompassPilot.Regulator regulator

_heading

protected float _heading

_estimatedHeading

protected float _estimatedHeading

_traveling

protected boolean _traveling

_distance

protected float _distance

_direction

protected byte _direction

_heading0

protected float _heading0

Constructor Detail

CompassPilot

public CompassPilot(DirectionFinder compass,
                    float wheelDiameter,
                    float trackWidth,
                    RegulatedMotor leftMotor,
                    RegulatedMotor rightMotor)

Allocates a CompasPilot object, and sets the physical parameters of the NXT robot.
Assumes Motor.forward() causes the robot to move forward); Parameters

Parameters:

compass - : a compass sensor;

wheelDiameter - Diameter of the tire, in any convenient units. (The diameter in mm is usually printed on the tire).

trackWidth - Distance between center of right tire and center of left tire, in same units as wheelDiameter

leftMotor -

rightMotor -

CompassPilot

public CompassPilot(DirectionFinder compass,
                    float wheelDiameter,
                    float trackWidth,
                    RegulatedMotor leftMotor,
                    RegulatedMotor rightMotor,
                    boolean reverse)

Allocates a CompasPilot object, and sets the physical parameters of the NXT robot.
Assumes Motor.forward() causes the robot to move forward); Parameters

Parameters:

compass - : a compass sensor;

wheelDiameter - Diameter of the tire, in any convenient units. (The diameter in mm is usually printed on the tire).

trackWidth - Distance between center of right tire and center of left tire, in same units as wheelDiameter

leftMotor -

rightMotor -

reverse - if true of motor.forward() drives the robot backwards

Method Detail

isTraveling

public boolean isTraveling()

returns returns true if the robot is travelling for a specific distance;

getCompass

public DirectionFinder getCompass()

Return the compass

Returns:

the compass

getAngleIncrement

public float getAngleIncrement()

Returns the change in robot heading since the last call of reset() normalized to be within -180 and _180 degrees

Overrides:

getAngleIncrement in class DifferentialPilot

Returns:

The angle rotated since rotation began.

getHeading

public float getHeading()

Returns direction of desired robot facing

getCompassHeading

public float getCompassHeading()

Method returns the current compass heading

Returns:

Compass heading in degrees.

setHeading

public void setHeading(float angle)

sets direction of desired robot facing in degrees

calibrate

public void calibrate()

Rotates the robot 360 degrees while calibrating the compass resets compass zero to heading at end of calibration

resetCartesianZero

public void resetCartesianZero()

getHeadingError

public float getHeadingError()

Determines the difference between actual compass direction and desired heading in degrees

Returns:

error (in degrees)

travel

public void travel(float distance,
                   boolean immediateReturn)

Moves the NXT robot a specific distance. A positive value moves it forwards and a negative value moves it backwards. The robot steers to maintain its compass heading.

Parameters:

distance - The positive or negative distance to move the robot, same units as _wheelDiameter

immediateReturn - iff true, the method returns immediately.

travel

public void travel(float distance)

Moves the NXT robot a specific distance;
A positive distance causes forward motion; negative distance moves backward. Robot steers to maintain its compass heading;

Parameters:

distance - of robot movement. Unit of measure for distance must be same as wheelDiameter and trackWidth

rotate

public void rotate(float angle,
                   boolean immediateReturn)

robot rotates to the specified compass heading;

Parameters:

immediateReturn - - if true, method returns immediately. Robot stops when specified angle is reached or when stop() is called

rotate

public void rotate(float angle)

Rotates the NXT robot through a specific angle; Rotates left if angle is positive, right if negative, Returns when angle is reached. Wheels turn in opposite directions producing a zero radius turn.

Parameters:

angle - degrees. Positive angle rotates to the left (clockwise); negative to the right.
Requires correct values for wheel diameter and track width.

reset

public void reset()

Description copied from class: DifferentialPilot

Resets tacho count for both motors.

Overrides:

reset in class DifferentialPilot

stopNow

protected void stopNow()

stop

public void stop()

Stops the robot soon after the method is executed. (It takes time for the motors to slow to a halt)

Specified by:

stop in interface MoveController

Overrides:

stop in class DifferentialPilot

normalize

protected float normalize(float angle)