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checkOccupancy

Check if locations are free or occupied

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Syntax

occStatus = checkOccupancy(map,xy)
occStatus = checkOccupancy(map,xy,"local")
occStatus = checkOccupancy(map,ij,"grid")
[occStatus,validPts] = checkOccupancy(___)
occStatusMatrix = checkOccupancy(map)
occStatusMatrix = checkOccupancy(map,bottomLeft,matSize)
occStatusMatrix = checkOccupancy(map,bottomLeft,matSize,"local")
occStatusMatrix = checkOccupancy(map,topLeft,matSize,"grid")

Description

The checkOccupancy function returns the occupancy statuses of specified locations in the binary occupancy map.

occStatus = checkOccupancy(map,xy) returns an array of occupancy statuses at the xy locations in the world frame. Obstacle-free cells return 0, occupied cells return 1. Unknown locations, including outside the map, return -1.

example

occStatus = checkOccupancy(map,xy,"local") returns an array of occupancy statuses at the xy locations in the local frame. The local frame is based on the LocalOriginInWorld property of the map.

example

occStatus = checkOccupancy(map,ij,"grid") specifies ij grid cell indices instead of xy locations. Grid indices start at (1,1) from the top left corner.

example

[occStatus,validPts] = checkOccupancy(___) also outputs an n-element vector of logical value indicating whether input coordinates are within the map limits.

occStatusMatrix = checkOccupancy(map) returns a matrix that contains the occupancy status of each location. Obstacle-free cells return 0, occupied cells return 1. Unknown locations, including outside the map, return -1.

occStatusMatrix = checkOccupancy(map,bottomLeft,matSize) returns a matrix of occupancy statuses by specifying the bottom-left corner location in world coordinates and the matrix size in meters.

occStatusMatrix = checkOccupancy(map,bottomLeft,matSize,"local") returns a matrix of occupancy statuses by specifying the bottom-left corner location in local coordinates and the matrix size in meters.

occStatusMatrix = checkOccupancy(map,topLeft,matSize,"grid") returns a matrix of occupancy statuses by specifying the top-left cell index in grid coordinates and the matrix size.

Examples

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Open Live Script

Access occupancy values and check their occupancy status based on the occupied and free thresholds of the occupancyMap object.

Create a matrix and populate it with values. Use this matrix to create an occupancy map.

p = zeros(20,20);
p(11:20,11:20) = ones(10,10);
map = binaryOccupancyMap(p,10);
show(map)

Figure contains an axes object. The axes object with title Binary Occupancy Grid, xlabel X [meters], ylabel Y [meters] contains an object of type image.

Get the occupancy of different locations and check their occupancy statuses. The occupancy status returns 0 for free space and 1 for occupied space. Unknown values return –1. 

pocc = getOccupancy(map,[1.5 1]);
occupied = checkOccupancy(map,[1.5 1]);
pocc2 = getOccupancy(map,[5 5],'grid');

Input Arguments

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Map representation, specified as a binaryOccupancyMap object.

Coordinates in the map, specified as an n-by-2 matrix of [x y] pairs, where n is the number of coordinates.

xy are world coordinates by default. If you specify "local", then xy are local coordinates. For example, checkOccupancy(map,[x1 y1],"local") checks the occupancy status at the specified xy local coordinates.

Data Types: double

Grid locations in the map, specified as an n-by-2 matrix of [i j] pairs, where n is the number of locations. Grid locations are given as [row col].

Data Types: double

Location of bottom left corner of output matrix in world or local coordinates, specified as a two-element vector, [xCoord yCoord].

bottomLeft is a world coordinate by default. If you specify "local", then bottomLeft is a local coordinate.

Data Types: double

Output matrix size, specified as a two-element vector, [xLength yLength], or [gridRow gridCol]. Size is in world, local, or grid coordinates based on syntax.

Data Types: double

Location of top left corner of grid, specified as a two-element vector, [iCoord jCoord].

Data Types: double

Output Arguments

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Occupancy status, returned as an n-by-1 column vector. n is equal to the length of the xy or ij input. Occupancy status can be obstacle free (0), occupied (1), or unknown (-1).

Valid map locations, returned as an n-by-1 column vector equal in length to xy or ij. Locations inside the map return a value of 1. Locations outside the map limits return a value of 0.

Matrix of occupancy status, returned as matrix with a size corresponding to matSize or the size of your map. Occupancy values can be obstacle free (0), occupied (1), or unknown (-1).

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

Version History

Introduced in R2019b

See Also

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