State validator based on 2-D grid map


The validatorOccupancyMap object validates states and discretized motions based on the value in a 2-D occupancy map. An occupied map location is interpreted as an invalid state.




validator = validatorOccupancyMap creates a 2-D occupancy map validator associated with an SE2 state space with default settings.


validator = validatorOccupancyMap(stateSpace) creates a validator in the given state space definition derived from nav.StateSpace.

validator = validatorOccupancyMap(stateSpace,Name,Value) specifies the Map or XYIndices properties using Name,Value pair arguments.


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State space for validating states, specified as a subclass of nav.StateSpace. Provided state space objects include:

Map used for validating states, specified as a binaryOccupancyMap or occupancyMap object.

Interval for sampling between states and checking state validity, specified as a positive numeric scalar.

State variable mapping for xy-coordinates in state vector, specified as a two-element vector, [xIdx yIdx]. For example, if a state vector is given as [r p y x y z], the xy-coordinates are [4 5].

Object Functions

copyCreate deep copy of state validator object
isStateValidCheck if state is valid
isMotionValidCheck if path between states is valid


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This example shows how to validate paths through an evironment.

Load example maps. Use the simple map to create a binary occupancy map.

load exampleMaps.mat
map = occupancyMap(simpleMap);

Specify a coarse path through the map.

path = [2 2 pi/2; 10 15 0; 17 8 -pi/2];
hold on

Create a state validator using the stateSpaceSE2 definition. Specify the map and the distance for interpolating and validating path segments.

validator = validatorOccupancyMap(stateSpaceSE2);
validator.Map = map;
validator.ValidationDistance = 0.1;

Check the points of the path are valid states. All three points are in free space, so are considered valid.

isValid = isStateValid(validator,path)
isValid = 3x1 logical array


Check the motion between each sequential path states. The isMotionValid function interpolates along the path between states. If a path segment is invalid, plot the last valid point along the path.

startStates = [path(1,:);path(2,:)];
endStates = [path(2,:);path(3,:)];
    for i = 1:2
        [isPathValid, lastValid] = isMotionValid(validator,startStates(i,:),endStates(i,:));
        if ~isPathValid
hold off

Extended Capabilities

Introduced in R2019b