lejos.navigation
Interface Navigator

All Known Subinterfaces:

Localizer

All Known Implementing Classes:

CompassNavigator, SimpleNavigator, TachoLocalizer, TachoNavigator, WaypointNavigator

public interface Navigator

The Navigator interface contains methods for performing basic navigational movements. Normally the Navigator class is instantiated as an object and methods are called on that object. Note: This class will only work for robots using two motors to steer differentially that can rotate within its footprint (i.e. turn on one spot). Modified by Roger Glassey 29 Jan 2007

Version:

0.2 - Jan-2007

Author:

Brian Bagnall

Method Summary

float	angleTo(float x, float y) returns the direction angle (degrees) to the point with coordinates (x,y)
void	backward() Moves the NXT robot backward until stop() is called.
float	distanceTo(float x, float y) returns the distance from robot to the point with coordinates (x,y) .
void	forward() Moves the NXT robot forward until stop() is called.
float	getAngle() Returns the current angle the NXT robot is facing.
float	getX() Returns the current x coordinate of the NXT.
float	getY() Returns the current y coordinate of the NXT.
void	goTo(float x, float y) Rotates the NXT robot towards the target point and moves the required distance.
void	goTo(float x, float y, boolean immediateReturn) Rotates the NXT robot towards the target point and moves the required distance.
boolean	isMoving() returns true iff the robot is moving under power
void	rotate(float angle) Rotates the NXT robot a specific number of degrees in a direction (+ or -).This method will return once the rotation is complete.
void	rotate(float angle, boolean immediateReturn) Rotates the NXT robot a specific number of degrees in a direction (+ or -).
void	rotateLeft() Rotates the NXT to the left (increasing angle) until stop() is called;
void	rotateRight() Rotates the NXT to the right (decreasing angle) until stop() is called;
void	rotateTo(float angle) Rotates the NXT robot to point in a specific direction.
void	rotateTo(float angle, boolean immediateReturn) Rotates the NXT robot to point in a specific direction.
void	setMoveSpeed(float speed) set the movement speed of the robot, wheel diameter units/sec
void	setPosition(float x, float y, float directionAngle) sets robot location (x,y) and direction angle
void	setTurnSpeed(float speed) sets the rotation speed of the robot in deg/secm when robot is turning in place
void	stop() Halts the NXT robot and calculates new x, y coordinates.
void	travel(float distance) Moves the NXT robot a specific distance.
void	travel(float distance, boolean immediateReturn) Moves the NXT robot a specific distance.
void	updatePosition() Updates robot location (x,y) and direction angle.

Method Detail

getX

float getX()

Returns the current x coordinate of the NXT. Note: At present it will only give an updated reading when the NXT is stopped.

Returns:

float Present x coordinate.

getY

float getY()

Returns the current y coordinate of the NXT. Note: At present it will only give an updated reading when the NXT is stopped.

Returns:

float Present y coordinate.

getAngle

float getAngle()

Returns the current angle the NXT robot is facing. Note: At present it will only give an updated reading when the NXT is stopped.

Returns:

float directionAngle in degrees.

isMoving

boolean isMoving()

returns true iff the robot is moving under power

setMoveSpeed

void setMoveSpeed(float speed)

set the movement speed of the robot, wheel diameter units/sec

setTurnSpeed

void setTurnSpeed(float speed)

sets the rotation speed of the robot in deg/secm when robot is turning in place

forward

void forward()

Moves the NXT robot forward until stop() is called.

See Also:

stop().

backward

void backward()

Moves the NXT robot backward until stop() is called.

See Also:

stop().

stop

void stop()

Halts the NXT robot and calculates new x, y coordinates.

See Also:

forward().

setPosition

void setPosition(float x,
                 float y,
                 float directionAngle)

sets robot location (x,y) and direction angle

Parameters:

x - the x coordinate of the robot

y - the y coordinate of the robot

directionAngle - the angle the robot is heading, measured from the x axis

rotateLeft

void rotateLeft()

Rotates the NXT to the left (increasing angle) until stop() is called;

rotateRight

void rotateRight()

Rotates the NXT to the right (decreasing angle) until stop() is called;

rotate

void rotate(float angle)

Rotates the NXT robot a specific number of degrees in a direction (+ or -).This method will return once the rotation is complete.

Parameters:

angle - Angle to rotate in degrees. A positive value rotates left, a negative value right.

rotate

void rotate(float angle,
            boolean immediateReturn)

Rotates the NXT robot a specific number of degrees in a direction (+ or -). If immediateReturn is true, method returns immediately and your code MUST call updatePostion() when the robot has stopped. Otherwise, the robot position is lost.

Parameters:

angle - Angle to rotate in degrees. A positive value rotates left, a negative value right.

immediateReturn - iff true, the method returns immediately, in which case the programmer
is responsible for calling updatePosition() before the robot moves again.

rotateTo

void rotateTo(float angle)

Rotates the NXT robot to point in a specific direction. It will take the shortest path necessary to point to the desired angle.

Parameters:

angle - The angle to rotate to, in degrees.

rotateTo

void rotateTo(float angle,
              boolean immediateReturn)

Rotates the NXT robot to point in a specific direction. It will take the shortest path necessary to point to the desired angle. If immediateReturnis true, method returns immidiately and your code MUST call updatePostion() when the robot has stopped. Otherwise, the robot position is lost.

Parameters:

angle - The angle to rotate to, in degrees.

immediateReturn - iff true, method returns immediately and the programmer is responsible for calling updatePosition() before the robot moves again.

travel

void travel(float distance)

Moves the NXT robot a specific distance. A positive value moves it forward and a negative value moves it backward. Method returns when movement is done.

Parameters:

distance - The positive or negative distance to move the robot.

travel

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. If immediateReturnis true, method returns immidiately and your code MUST call updatePostion() when the robot has stopped. Otherwise, the robot position is lost.

Parameters:

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

immediateReturn - iff true, the method returns immediately, in which case the programmer
is responsible for calling updatePosition() before the robot moves again.

goTo

void goTo(float x,
          float y)

Rotates the NXT robot towards the target point and moves the required distance.

Parameters:

x - The x coordinate to move to.

y - The y coordinate to move to.

goTo

void goTo(float x,
          float y,
          boolean immediateReturn)

Rotates the NXT robot towards the target point and moves the required distance.

Parameters:

x - The x coordinate to move to.

y - The y coordinate to move to.

immediateReturn - Indicates whether method should return immediately.

distanceTo

float distanceTo(float x,
                 float y)

returns the distance from robot to the point with coordinates (x,y) .

Parameters:

x - coordinate of the point

y - coordinate of the point

Returns:

the distance from the robot current location to the point

angleTo

float angleTo(float x,
              float y)

returns the direction angle (degrees) to the point with coordinates (x,y)

Parameters:

x - coordinate of the point

y - coordinate of the point

Returns:

the direction angle to the point (x,y) from the NXT. Rotate to this angle to head toward it.

updatePosition

void updatePosition()

Updates robot location (x,y) and direction angle. Called by stop, and movement commands that terminate when complete. Must be called after a command that returns immediatly, but after robot movement stops, and before another movement method is called.