SearchWorldState (Autonomous Unmanned Vehicle (AUV) Workbench Documentation)

java.lang.Object
- planner.aStarPlan.WorldState
- - planner.avclPlan.search.SearchWorldState

Direct Known Subclasses:

BestFirstSearchWorldState, BreadthFirstSearchWorldState
```
public class SearchWorldState
extends WorldState
```
Represents the state of the world at various stages of a search. Conditions consist of "visited" conditions where the search is complete when all of the locations have been visited. The estimate of remaining cost is the track spacing times the number of unvisited locations. Incurred cost so far is the distance traveled on all of the legs so far plus the track spacing times the number of legs (this biases the searh towards patterns with fewer long legs rather than numerous short legs)

Version:

$Revision: 1.13 $

Author:

dtdavis
Contact: Don Brutzman (web.nps.navy.mil/~brutzman) brutzman@nps.navy.mil

Field Summary

Fields
Modifier and Type	Field and Description
`protected double[]`	`buffer`
`static double`	`FORTY_FIVE_DEGREES`
`static double[]`	`HEADINGS`
`static double`	`NINETY_DEGREES`
`static double`	`ONE_FIFTY_DEGREES`
`static double`	`ONE_THIRTY_FIVE_DEGREES`
`static double`	`ONE_TWENTY_DEGREES`
`protected boolean`	`pointFocus` Set to true if the search is a point search (false means area search)
`protected GeoArea`	`searchArea` Reference to the Geographic area that his search planner is to generate a search pattern for
`protected List<double[]>`	`searchPoints` List of double[2] (x, y) positions that must be visited to complete the search
`static double`	`SIXTY_DEGREES`
`static double`	`THIRTY_DEGREES`
`static double`	`THREE_FIFTEEN_DEGREES`
`static double`	`THREE_HUNDRED_DEGREES`
`static double`	`THREE_THIRTY_DEGREES`
`protected double`	`trackLengthMultiple` Applied to individual search legs to expedite the search
`protected double`	`trackSpacing` Spacing between tracks (used to compute estimate of remaining distance to goal)
`static double`	`TWO_FORTY_DEGREES`
`static double`	`TWO_SEVENTY_DEGREES`
`static double`	`TWO_TEN_DEGREES`
`static double`	`TWO_TWENTY_FIVE_DEGREES`
`protected double[]`	`vehiclePosition` Position of the vehicle in the world upon completion of this step
`protected double`	`vehiclePsi` Current heading (radians) of the vehicle at the end of this step

Constructor Summary

Constructors
Modifier	Constructor and Description
`protected`	`SearchWorldState()` Creates a new instance of SearchWorldState
`protected`	`SearchWorldState(List<double[]> searchPoints, GeoArea searchArea, double spacing, double[] position)` Creates a new instance of SearchWorldState
`protected`	`SearchWorldState(List<double[]> searchPoints, GeoArea searchArea, double spacing, double[] position, boolean pointFocus)` Creates a new instance of SearchWorldState
`protected`	`SearchWorldState(List<double[]> searchPoints, GeoArea searchArea, List<double[]> complete, double spacing, double[] position)` Creates a new instance of SearchWorldState
`protected`	`SearchWorldState(List<double[]> searchPoints, GeoArea searchArea, List<double[]> complete, double spacing, double[] position, boolean pointFocus)` Creates a new instance of SearchWorldState

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`protected void`	`addVisited(double[] point)` Adds a condition for visiting a search point
`void`	`computePsi(SearchWorldState previousState)` Computes the heading of the vehicle in this state based on the previous vehicle position
`WorldState`	`computeStepEffect(PlanStep step)` Computes the effect of a plan step on the world state conditions
`protected void`	`generateConditions(List<double[]> points)` Generates the conditions that describe the world state based on a set of searched points
`List<SearchPlanStep>`	`possibleSteps()` Returns an ArrayList containing all steps that are possible from the current state
`protected boolean`	`visited(double[] point)` Determines whether the search has covered the test point
`double`	`worldStateDistance(WorldState candidate)` Compares this state with another to measure how different they are in order to provide an estimate of how much effort will be required to go from this state to the candidate state.

Methods inherited from class planner.aStarPlan.WorldState
addCondition, addCondition, getCondition, hasCondition, match, numberOfConditions, toString

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - THIRTY_DEGREES
```
public static final double THIRTY_DEGREES
```
    See Also:
    
    Constant Field Values
  - FORTY_FIVE_DEGREES
```
public static final double FORTY_FIVE_DEGREES
```
    See Also:
    
    Constant Field Values
  - SIXTY_DEGREES
```
public static final double SIXTY_DEGREES
```
    See Also:
    
    Constant Field Values
  - NINETY_DEGREES
```
public static final double NINETY_DEGREES
```
    See Also:
    
    Constant Field Values
  - ONE_TWENTY_DEGREES
```
public static final double ONE_TWENTY_DEGREES
```
    See Also:
    
    Constant Field Values
  - ONE_THIRTY_FIVE_DEGREES
```
public static final double ONE_THIRTY_FIVE_DEGREES
```
    See Also:
    
    Constant Field Values
  - ONE_FIFTY_DEGREES
```
public static final double ONE_FIFTY_DEGREES
```
    See Also:
    
    Constant Field Values
  - TWO_TEN_DEGREES
```
public static final double TWO_TEN_DEGREES
```
    See Also:
    
    Constant Field Values
  - TWO_TWENTY_FIVE_DEGREES
```
public static final double TWO_TWENTY_FIVE_DEGREES
```
    See Also:
    
    Constant Field Values
  - TWO_FORTY_DEGREES
```
public static final double TWO_FORTY_DEGREES
```
    See Also:
    
    Constant Field Values
  - TWO_SEVENTY_DEGREES
```
public static final double TWO_SEVENTY_DEGREES
```
    See Also:
    
    Constant Field Values
  - THREE_HUNDRED_DEGREES
```
public static final double THREE_HUNDRED_DEGREES
```
    See Also:
    
    Constant Field Values
  - THREE_FIFTEEN_DEGREES
```
public static final double THREE_FIFTEEN_DEGREES
```
    See Also:
    
    Constant Field Values
  - THREE_THIRTY_DEGREES
```
public static final double THREE_THIRTY_DEGREES
```
    See Also:
    
    Constant Field Values
  - HEADINGS
```
public static final double[] HEADINGS
```
  - searchPoints
```
protected List<double[]> searchPoints
```
    List of double[2] (x, y) positions that must be visited to complete the search
  - trackSpacing
```
protected double trackSpacing
```
    Spacing between tracks (used to compute estimate of remaining distance to goal)
  - vehiclePosition
```
protected double[] vehiclePosition
```
    Position of the vehicle in the world upon completion of this step
  - vehiclePsi
```
protected double vehiclePsi
```
    Current heading (radians) of the vehicle at the end of this step
  - searchArea
```
protected GeoArea searchArea
```
    Reference to the Geographic area that his search planner is to generate a search pattern for
  - trackLengthMultiple
```
protected double trackLengthMultiple
```
    Applied to individual search legs to expedite the search
  - pointFocus
```
protected boolean pointFocus
```
    Set to true if the search is a point search (false means area search)
  - buffer
```
protected double[] buffer
```
- Constructor Detail
  - SearchWorldState
```
protected SearchWorldState()
```
    Creates a new instance of SearchWorldState
  - SearchWorldState
```
protected SearchWorldState(List<double[]> searchPoints,
                           GeoArea searchArea,
                           List<double[]> complete,
                           double spacing,
                           double[] position)
```
    Creates a new instance of SearchWorldState
    
    Parameters:
    
    searchPoints - List of points that are to be visited during the search
    
    searchArea - Geographic area that the planner is to devise a search pattern for
    
    complete - List of points that have been visited to date
    
    spacing - track spacing to be used during the search
    
    position - double[2] containing the current (x, y) position of the vehicle
  - SearchWorldState
```
protected SearchWorldState(List<double[]> searchPoints,
                           GeoArea searchArea,
                           double spacing,
                           double[] position)
```
    Creates a new instance of SearchWorldState
    
    Parameters:
    
    searchPoints - List of points that are to be visited during the search
    
    searchArea - Geographic area that the planner is to devise a search pattern for
    
    spacing - track spacing to be used during the search
    
    position - double[2] containing the current (x, y) position of the vehicle
  - SearchWorldState
```
protected SearchWorldState(List<double[]> searchPoints,
                           GeoArea searchArea,
                           List<double[]> complete,
                           double spacing,
                           double[] position,
                           boolean pointFocus)
```
    Creates a new instance of SearchWorldState
    
    Parameters:
    
    searchPoints - List of points that are to be visited during the search
    
    searchArea - Geographic area that the planner is to devise a search pattern for
    
    complete - List of points that have been visited to date
    
    spacing - track spacing to be used during the search
    
    position - double[2] containing the current (x, y) position of the vehicle
    
    pointFocus -
  - SearchWorldState
```
protected SearchWorldState(List<double[]> searchPoints,
                           GeoArea searchArea,
                           double spacing,
                           double[] position,
                           boolean pointFocus)
```
    Creates a new instance of SearchWorldState
    
    Parameters:
    
    searchPoints - List of points that are to be visited during the search
    
    searchArea - Geographic area that the planner is to devise a search pattern for
    
    spacing - track spacing to be used during the search
    
    position - double[2] containing the current (x, y) position of the vehicle
    
    pointFocus -
- Method Detail
  - computeStepEffect
```
public WorldState computeStepEffect(PlanStep step)
```
    Computes the effect of a plan step on the world state conditions
    
    Specified by:
    
    computeStepEffect in class WorldState
    
    Parameters:
    
    step - PlanStep object.
    
    Returns:
    
    the effect of a plan step on the world state conditions.
  - worldStateDistance
```
public double worldStateDistance(WorldState candidate)
```
    Compares this state with another to measure how different they are in order to provide an estimate of how much effort will be required to go from this state to the candidate state. This particular metric is based on the number of conditions present in the candidate that are not present in the current state and returns the number * trackSpacing * 10. This heavily biases the A* search towards covering the points in as few steps as possible, as opposed to the shortest distance covered.
    
    Specified by:
    
    worldStateDistance in class WorldState
    
    Parameters:
    
    candidate - WorldState object.
    
    Returns:
    
    the value of double of comparison this state with another.
  - possibleSteps
```
public List<SearchPlanStep> possibleSteps()
```
    Returns an ArrayList containing all steps that are possible from the current state
    
    Specified by:
    
    possibleSteps in class WorldState
    
    Returns:
    
    an ArrayList containing all steps.
  - generateConditions
```
protected final void generateConditions(List<double[]> points)
```
    Generates the conditions that describe the world state based on a set of searched points
    
    Parameters:
    
    points - points that are searched when the world is in this state
  - addVisited
```
protected void addVisited(double[] point)
```
    Adds a condition for visiting a search point
    
    Parameters:
    
    point - double[2] with the (x, y) position of the visited point
  - visited
```
protected boolean visited(double[] point)
```
    Determines whether the search has covered the test point
    
    Parameters:
    
    point - double[2] containing the (x,y) position of the point being tested
    
    Returns:
    
    'true' if "point" been visited already
  - computePsi
```
public void computePsi(SearchWorldState previousState)
```
    Computes the heading of the vehicle in this state based on the previous vehicle position
    
    Parameters:
    
    previousState -

Class SearchWorldState

Field Summary

Constructor Summary

Method Summary

Methods inherited from class planner.aStarPlan.WorldState

Methods inherited from class java.lang.Object

Field Detail

THIRTY_DEGREES

FORTY_FIVE_DEGREES

SIXTY_DEGREES

NINETY_DEGREES

ONE_TWENTY_DEGREES

ONE_THIRTY_FIVE_DEGREES

ONE_FIFTY_DEGREES

TWO_TEN_DEGREES

TWO_TWENTY_FIVE_DEGREES

TWO_FORTY_DEGREES

TWO_SEVENTY_DEGREES

THREE_HUNDRED_DEGREES

THREE_FIFTEEN_DEGREES

THREE_THIRTY_DEGREES

HEADINGS

searchPoints

trackSpacing

vehiclePosition

vehiclePsi

searchArea

trackLengthMultiple

pointFocus

buffer

Constructor Detail

SearchWorldState

SearchWorldState

SearchWorldState

SearchWorldState

SearchWorldState

Method Detail

computeStepEffect

worldStateDistance

possibleSteps

generateConditions

addVisited

visited

computePsi