burlap.domain.singleagent.lunarlander

Class LunarLanderDomain

java.lang.Object

burlap.domain.singleagent.lunarlander.LunarLanderDomain

All Implemented Interfaces:

DomainGenerator

public class LunarLanderDomain
extends java.lang.Object
implements DomainGenerator

This domain generator is used for producing a Lunar Lander domain, based on the classic Lunar Lander Atari game (1979). The agent pilots a lunar lander that has a variety of thrust actions and can rotate clockwise or counter clockwise. The agent may also do nothing and just drift. Using a thrust action exerts force in the opposite direction the lander is oriented. Gravity acts on the agent so the agent must find the right balance of thrust to take off and reach some designated landing position.

The agent object class is made up of 5 attributes, x-y position, x-y velocity, and the angle or orientation (in radians from the default vertical orientation). Two other object classes are defined for landing pads and obstacles. Both are objects are defined as a rectangular region with a left, right, bottom, and top attribute defining the space. Typically, the goal is for the agent to land on the land pad while avoiding the obstacles.

The domain generator allows the client to specify the physics and action definitions for the lunar lander. In particular the client can add as many thrust actions (each with their own thrust force) as desired, the force of gravity can be changed, the size of the domain (that is, the x space and y space in which the agent can fly before hitting a "wall") can be changed, the maximum lander rotation can be set, and the rotate increment size that results from applying a clockwise/counterclockwise rotate action can also be set. There is also a method to set the domain to a standard set of physics and actions.

If the domain generator physics parameters are changed after a domain has been generated, the previously generated domain will remain unaffected, allowing you to reuse the same domain generator to produce different versions of the domain without conflict.

Author:

James MacGlashan

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	LunarLanderDomain.ActionIdle An action class for having the agent idle (its current velocity and the force of gravity will be all that acts on the lander).
class	LunarLanderDomain.ActionThrust An action class for exerting a thrust.
class	LunarLanderDomain.ActionTurn An action class for turning the lander
static class	LunarLanderDomain.LLPhysicsParams A class for holding the physics parameters
class	LunarLanderDomain.OnPadPF A propositional function that evaluates to true if the agent has landed on the top surface of a landing pad.
class	LunarLanderDomain.TouchGroundPF A propositional function that evaluates to true if the agent is touching the ground.
class	LunarLanderDomain.TouchPadPF A propositional function that evaluates to true if the agent is touching any part of the landing pad, including its side boundaries.
class	LunarLanderDomain.TouchSurfacePF A propositional function that evaluates to true if the agent is touching any part of an obstacle, including its side boundaries.

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	AATTNAME Constant for the name of the angle of orientation attribute.
static java.lang.String	ACTIONIDLE Constant for the name of the idle action which causes the agent to do nothing by drift for a time step
static java.lang.String	ACTIONTHRUST Constant for the base name of thrust actions.
static java.lang.String	ACTIONTURNL Constant for the name of the turn/rotate left/counterclockwise action
static java.lang.String	ACTIONTURNR Constant for the name of the turn/rotate right/clockwise action
static java.lang.String	AGENTCLASS Constant for the name of the agent OO-MDP class
static java.lang.String	BATTNAME Constant for the name of the bottom boundary attribute for rectangular obstacles and landing pads
static java.lang.String	LATTNAME Constant for the name of the left boundary attribute for rectangular obstacles and landing pads
static java.lang.String	OBSTACLECLASS Constant for the name of the obstacle OO-MDP class
static java.lang.String	PADCLASS Constant for the name of the goal landing pad OO-MDP class
static java.lang.String	PFONGROUND Constant for the name of the propositional function that indicates whether the agent/lander is on the ground
static java.lang.String	PFONPAD Constant for the name of the propositional function that indicates whether the agent/lander is on a landing pad
static java.lang.String	PFTOUCHSURFACE Constant for the name of the propositional function that indicates whether the agent/lander is touching an obstacle surface.
static java.lang.String	PFTPAD Constant for the name of the propositional function that indicates whether the agent/lander is *touching* a landing pad.
protected LunarLanderDomain.LLPhysicsParams	physParams An object for holding the physics parameters of this domain.
static java.lang.String	RATTNAME Constant for the name of the right boundary attribute for rectangular obstacles and landing pads
static java.lang.String	TATTNAME Constant for the name of the top boundary attribute for rectangular obstacles and landing pads
protected java.util.List<java.lang.Double>	thrustValues List of the thrust forces for each thrust action
static java.lang.String	VXATTNAME Constant for the name of the x velocity attribute.
static java.lang.String	VYATTNAME Constant for the name of the y velocity attribute.
static java.lang.String	XATTNAME Constant for the name of the x position attribute.
static java.lang.String	YATTNAME Constant for the name of the y position attribute.

Constructor Summary

Constructors

Constructor and Description
LunarLanderDomain() Initializes with no thrust actions set.

Method Summary

Methods

Modifier and Type	Method and Description
void	addStandardThrustActions() Adds two standard thrust actions. thrust1 force = 0.32 thrust2 force = 0.2 (opposite gravity)
void	addThrustActionWithThrust(double t) Adds a thrust action with thrust force t
Domain	generateDomain() Returns a newly instanced Domain object
double	getAnginc() Returns how many radians the agent will rotate from its current orientation when a turn/rotate action is applied
double	getAngmax() Returns the maximum rotate angle (in radians) that the lander can be rotated from the vertical orientation in either clockwise or counterclockwise direction.
static State	getCleanState(Domain domain, int no) Creates a state with one agent/lander, one landing pad, and no number of obstacles.
LunarLanderDomain.LLPhysicsParams	getPhysParams()
double	getVmax() Returns the maximum velocity of the agent (the agent cannot move faster than this value).
double	getXmax() Returns the maximum x position of the lander (the agent cannot cross this boundary)
double	getXmin() Returns the minimum x position of the lander (the agent cannot cross this boundary)
double	getYmax() Returns the maximum y position of the lander (the agent cannot cross this boundary)
double	getYmin() Returns the minimum y position of the lander (the agent cannot cross this boundary)
protected static void	incAngle(State s, double dir, LunarLanderDomain.LLPhysicsParams physParams) Turns the lander in the direction indicated by the domains defined change in angle for turn actions.
static void	main(java.lang.String[] args) This method will launch a visual explorer for the lunar lander domain.
static void	setAgent(State s, double a, double x, double y) Sets the agent/lander position/orientation and zeros out the lander velocity.
static void	setAgent(State s, double a, double x, double y, double vx, double vy) Sets the agent/lander position/orientation and the velocity.
void	setAnginc(double anginc) Sets how many radians the agent will rotate from its current orientation when a turn/rotate action is applied
void	setAngmax(double angmax) Sets the maximum rotate angle (in radians) that the lander can be rotated from the vertical orientation in either clockwise or counterclockwise direction.
void	setGravity(double g) Sets the gravity of the domain
static void	setObstacle(State s, int i, double l, double r, double b, double t) Sets an obstacles boundaries/position
static void	setPad(State s, double l, double r, double b, double t) Sets the first landing pad's boundaries/position
static void	setPad(State s, int i, double l, double r, double b, double t) Sets a landing pad's boundaries/position
void	setPhysParams(LunarLanderDomain.LLPhysicsParams physParams)
void	setToStandardLunarLander() Sets the domain to use a standard set of physics and with a standard set of two thrust actions. gravity = -0.2 xmin = 0 xmax = 100 ymin = 0 ymax = 50 max velocity component speed = 4 maximum angle of rotation = pi/4 change in angle from turning = pi/20 thrust1 force = 0.32 thrust2 force = 0.2 (opposite gravity)
void	setVmax(double vmax) Sets the maximum velocity of the agent (the agent cannot move faster than this value).
void	setXmax(double xmax) Sets the maximum x position of the lander (the agent cannot cross this boundary)
void	setXmin(double xmin) Sets the minimum x position of the lander (the agent cannot cross this boundary)
void	setYmax(double ymax) Sets the maximum y position of the lander (the agent cannot cross this boundary)
void	setYmin(double ymin) Sets the minimum y position of the lander (the agent cannot cross this boundary)
protected static void	updateMotion(State s, double thrust, LunarLanderDomain.LLPhysicsParams physParams) Updates the position of the agent/lander given the provided thrust force that has been exerted

Methods inherited from class java.lang.Object

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

Field Detail

XATTNAME

public static final java.lang.String XATTNAME

Constant for the name of the x position attribute.

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Constant Field Values

YATTNAME

public static final java.lang.String YATTNAME

Constant for the name of the y position attribute.

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Constant Field Values

VXATTNAME

public static final java.lang.String VXATTNAME

Constant for the name of the x velocity attribute.

See Also:

Constant Field Values

VYATTNAME

public static final java.lang.String VYATTNAME

Constant for the name of the y velocity attribute.

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Constant Field Values

AATTNAME

public static final java.lang.String AATTNAME

Constant for the name of the angle of orientation attribute.

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Constant Field Values

LATTNAME

public static final java.lang.String LATTNAME

Constant for the name of the left boundary attribute for rectangular obstacles and landing pads

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Constant Field Values

RATTNAME

public static final java.lang.String RATTNAME

Constant for the name of the right boundary attribute for rectangular obstacles and landing pads

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Constant Field Values

BATTNAME

public static final java.lang.String BATTNAME

Constant for the name of the bottom boundary attribute for rectangular obstacles and landing pads

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Constant Field Values

TATTNAME

public static final java.lang.String TATTNAME

Constant for the name of the top boundary attribute for rectangular obstacles and landing pads

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Constant Field Values

AGENTCLASS

public static final java.lang.String AGENTCLASS

Constant for the name of the agent OO-MDP class

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Constant Field Values

OBSTACLECLASS

public static final java.lang.String OBSTACLECLASS

Constant for the name of the obstacle OO-MDP class

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Constant Field Values

PADCLASS

public static final java.lang.String PADCLASS

Constant for the name of the goal landing pad OO-MDP class

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Constant Field Values

ACTIONTURNL

public static final java.lang.String ACTIONTURNL

Constant for the name of the turn/rotate left/counterclockwise action

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Constant Field Values

ACTIONTURNR

public static final java.lang.String ACTIONTURNR

Constant for the name of the turn/rotate right/clockwise action

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Constant Field Values

ACTIONTHRUST

public static final java.lang.String ACTIONTHRUST

Constant for the base name of thrust actions. Each thrust action will have a number appended to this name to indicate which thrust action it is.

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Constant Field Values

ACTIONIDLE

public static final java.lang.String ACTIONIDLE

Constant for the name of the idle action which causes the agent to do nothing by drift for a time step

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Constant Field Values

PFONPAD

public static final java.lang.String PFONPAD

Constant for the name of the propositional function that indicates whether the agent/lander is on a landing pad

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Constant Field Values

PFTPAD

public static final java.lang.String PFTPAD

Constant for the name of the propositional function that indicates whether the agent/lander is *touching* a landing pad. Note that the agent may be touching the pad on the side of its boundaries and therefore not be landed on it. However if the agent is landed on the pad, then they will also be touching it.

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Constant Field Values

PFTOUCHSURFACE

public static final java.lang.String PFTOUCHSURFACE

Constant for the name of the propositional function that indicates whether the agent/lander is touching an obstacle surface.

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Constant Field Values

PFONGROUND

public static final java.lang.String PFONGROUND

Constant for the name of the propositional function that indicates whether the agent/lander is on the ground

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Constant Field Values

thrustValues

protected java.util.List<java.lang.Double> thrustValues

List of the thrust forces for each thrust action

physParams

protected LunarLanderDomain.LLPhysicsParams physParams

An object for holding the physics parameters of this domain.

Constructor Detail

LunarLanderDomain

public LunarLanderDomain()

Initializes with no thrust actions set.

Method Detail

setAgent

public static void setAgent(State s,
            double a,
            double x,
            double y)

Sets the agent/lander position/orientation and zeros out the lander velocity.

Parameters:

s - the state in which to set the agent

a - the angle of the lander

x - the x position

y - the y position

setAgent

public static void setAgent(State s,
            double a,
            double x,
            double y,
            double vx,
            double vy)

Sets the agent/lander position/orientation and the velocity.

Parameters:

s - the state in which to set the agent

a - the angle of the lander

x - the x position of the lander

y - the y position of the lander

vx - the x velocity component of the lander

vy - the y velocity component of the lander

setObstacle

public static void setObstacle(State s,
               int i,
               double l,
               double r,
               double b,
               double t)

Sets an obstacles boundaries/position

Parameters:

s - the state in which the obstacle should be set

i - specifies the ith landing pad object to be set to these values

l - the left boundary

r - the right boundary

b - the bottom boundary

t - the top boundary

setPad

public static void setPad(State s,
          double l,
          double r,
          double b,
          double t)

Sets the first landing pad's boundaries/position

Parameters:

s - the state in which the obstacle should be set

l - the left boundary

r - the right boundary

b - the bottom boundary

t - the top boundary

setPad

public static void setPad(State s,
          int i,
          double l,
          double r,
          double b,
          double t)

Sets a landing pad's boundaries/position

Parameters:

s - the state in which the obstacle should be set

i - specifies the ith landing pad object to be set to these values

l - the left boundary

r - the right boundary

b - the bottom boundary

t - the top boundary

addThrustActionWithThrust

public void addThrustActionWithThrust(double t)

Adds a thrust action with thrust force t

Parameters:

t - the thrust of the thrust force to add

getPhysParams

public LunarLanderDomain.LLPhysicsParams getPhysParams()

setPhysParams

public void setPhysParams(LunarLanderDomain.LLPhysicsParams physParams)

setGravity

public void setGravity(double g)

Sets the gravity of the domain

Parameters:

g - the force of gravity

getXmin

public double getXmin()

Returns the minimum x position of the lander (the agent cannot cross this boundary)

Returns:

the minimum x position of the lander (the agent cannot cross this boundary)

setXmin

public void setXmin(double xmin)

Sets the minimum x position of the lander (the agent cannot cross this boundary)

Parameters:

xmin - the minimum x position of the lander (the agent cannot cross this boundary)

getXmax

public double getXmax()

Returns the maximum x position of the lander (the agent cannot cross this boundary)

Returns:

the maximum x position of the lander (the agent cannot cross this boundary)

setXmax

public void setXmax(double xmax)

Sets the maximum x position of the lander (the agent cannot cross this boundary)

Parameters:

xmax - the maximum x position of the lander (the agent cannot cross this boundary)

getYmin

public double getYmin()

Returns the minimum y position of the lander (the agent cannot cross this boundary)

Returns:

the minimum y position of the lander (the agent cannot cross this boundary)

setYmin

public void setYmin(double ymin)

Sets the minimum y position of the lander (the agent cannot cross this boundary)

Parameters:

ymin - the minimum y position of the lander (the agent cannot cross this boundary)

getYmax

public double getYmax()

Returns the maximum y position of the lander (the agent cannot cross this boundary)

Returns:

the maximum y position of the lander (the agent cannot cross this boundary)

setYmax

public void setYmax(double ymax)

Sets the maximum y position of the lander (the agent cannot cross this boundary)

Parameters:

ymax - the maximum y position of the lander (the agent cannot cross this boundary)

getVmax

public double getVmax()

Returns the maximum velocity of the agent (the agent cannot move faster than this value).

Returns:

the maximum velocity of the agent (the agent cannot move faster than this value).

setVmax

public void setVmax(double vmax)

Sets the maximum velocity of the agent (the agent cannot move faster than this value).

Parameters:

vmax - the maximum velocity of the agent (the agent cannot move faster than this value).

getAngmax

public double getAngmax()

Returns the maximum rotate angle (in radians) that the lander can be rotated from the vertical orientation in either clockwise or counterclockwise direction.

Returns:

the maximum rotate angle (in radians) that the lander can be rotated

setAngmax

public void setAngmax(double angmax)

Sets the maximum rotate angle (in radians) that the lander can be rotated from the vertical orientation in either clockwise or counterclockwise direction.

Parameters:

angmax - the maximum rotate angle (in radians) that the lander can be rotated

getAnginc

public double getAnginc()

Returns how many radians the agent will rotate from its current orientation when a turn/rotate action is applied

Returns:

how many radians the agent will rotate from its current orientation when a turn/rotate action is applied

setAnginc

public void setAnginc(double anginc)

Sets how many radians the agent will rotate from its current orientation when a turn/rotate action is applied

Parameters:

anginc - how many radians the agent will rotate from its current orientation when a turn/rotate action is applied

setToStandardLunarLander

public void setToStandardLunarLander()

Sets the domain to use a standard set of physics and with a standard set of two thrust actions.
gravity = -0.2
xmin = 0
xmax = 100
ymin = 0
ymax = 50
max velocity component speed = 4
maximum angle of rotation = pi/4
change in angle from turning = pi/20
thrust1 force = 0.32
thrust2 force = 0.2 (opposite gravity)

addStandardThrustActions

public void addStandardThrustActions()

Adds two standard thrust actions.
thrust1 force = 0.32
thrust2 force = 0.2 (opposite gravity)

generateDomain

public Domain generateDomain()

Description copied from interface: DomainGenerator

Returns a newly instanced Domain object

Specified by:

generateDomain in interface DomainGenerator

Returns:

the newly instantiated Domain object.

getCleanState

public static State getCleanState(Domain domain,
                  int no)

Creates a state with one agent/lander, one landing pad, and no number of obstacles. The attribute values of these objects will be uninitialized and will need to be set either manually or with this class's methods like setAgent(burlap.oomdp.core.State, double, double, double).

Parameters:

domain - the domain of the state to generate

no - the number of obstacle objects to create

Returns:

a state object

incAngle

protected static void incAngle(State s,
            double dir,
            LunarLanderDomain.LLPhysicsParams physParams)

Turns the lander in the direction indicated by the domains defined change in angle for turn actions.

Parameters:

s - the state in which the lander's angle should be changed

dir - the direction to turn; +1 is clockwise, -1 is counterclockwise

updateMotion

protected static void updateMotion(State s,
                double thrust,
                LunarLanderDomain.LLPhysicsParams physParams)

Updates the position of the agent/lander given the provided thrust force that has been exerted

Parameters:

s - the state in which the agent/lander should be modified

thrust - the amount of thrust force exerted by the lander.

main

public static void main(java.lang.String[] args)

This method will launch a visual explorer for the lunar lander domain. It will use the default physics, start the agent on the left side of the world with a landing pad on the right and an obstacle in between. The agent is controlled with the following keys:
w: heavy thrust
s: weak thrust
a: turn/rotate counterclockwise
d: turn/rotate clockwise
x: idle (drift for one time step)

If you pass the main method "t" as an argument, a terminal explorer will be used instead of a visual explorer.

Parameters:

args - optionally pass "t" asn argument to use a terminal explorer instead of a visual explorer.