Update states of obstacles
Build an ego body path and maintain obstacle states using the
dynamicCapsuleList object. Visualize the states of all objects in the environment at different timestamps. Validate the path of the ego body by checking for collisions with obstacles in the environment.
dynamicCapsuleList object. Extract the maximum number of steps to use as the number of time stamps for your object paths.
obsList = dynamicCapsuleList; numSteps = obsList.MaxNumSteps;
Add Ego Body
Define an ego body by specifying the ID, geometry, and state together in a structure. The capsule geometry has a length of 3 m and radius of 1 m. Specify the state as a linear path from x = 0m to x = 100m.
egoID1 = 1; geom = struct("Length",3,"Radius",1,"FixedTransform",eye(3)); states = linspace(0,1,obsList.MaxNumSteps)'.*[100 0 0]; egoCapsule1 = struct('ID',egoID1,'States',states,'Geometry',geom); addEgo(obsList,egoCapsule1); show(obsList,"TimeStep",[1:numSteps]); ylim([-20 20])
Specify states for two obstacles that are separated from the ego body by 5 m in opposite directions on the y-axis.. Assume the obstacles have the same geometry
geom as the ego body.
obsState1 = states + [0 5 0]; obsState2 = states + [0 -5 0]; obsCapsule1 = struct('ID',1,'States',obsState1,'Geometry',geom); obsCapsule2 = struct('ID',2,'States',obsState2,'Geometry',geom); addObstacle(obsList,obsCapsule1); addObstacle(obsList,obsCapsule2); show(obsList,"TimeStep",[1:numSteps]); ylim([-20 20])
Alter your obstacle locations and geometry dimensions over time. Use the previously generated structure, modify the fields, and update the obstacles using the
updateObstaclePose object functions. Reduces the radius of the first obstacle to 0.5 m, and change the path to move it towards the ego body.
obsCapsule1.Geometry.Radius = 0.5; obsCapsule1.States = ... [linspace(0,100,numSteps)' ... % x linspace(5,-4,numSteps)' ... % y zeros(numSteps,1)]; % theta updateObstacleGeometry(obsList,1,obsCapsule1); updateObstaclePose(obsList,1,obsCapsule1);
Check for Collisions
Visualize the new paths. Show where collisions between the ego body and an obstacle, which the display highlights in red. Notice that collisions between the obstacles are not checked.
show(obsList,"TimeStep",[1:numSteps],"ShowCollisions",1); ylim([-20 20]) xlabel("X (m)") ylabel("Y (m)")
Programmatically check for collisions by using the
checkCollision object function. The function returns a vector of logical values that indicates the status of each time step. The vector is transposed for display purposes.
collisions = checkCollision(obsList)'
collisions = 1x31 logical array 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0
To validate paths with a large number of steps, use the
any function on the vector of collision values.
if any(collisions) disp("Collision detected.") end
Update Ego Path
Specify a new path for the ego body. Visualize the paths again, displaying collisions.
egoCapsule1.States = ... [linspace(0,100,numSteps)' ... % x 3*sin(linspace(0,2*pi,numSteps))' ... % y zeros(numSteps,1)]; % theta updateEgoPose(obsList,1,egoCapsule1); show(obsList,"TimeStep",[1:numSteps],"ShowCollisions",1); ylim([-20 20])
obstacleIDs— IDs of obstacles to update
IDs of obstacles to update, specified as a vector of positive integers.
poseStruct— States for obstacles
States for ego bodies, specified as a structure or structure array, where each
structure contains the fields of the structure in the
of the obstacle to be updated. Each element of the structure array contains a matrix of
states for each ego body. The state matrix size depends on whether you are using a
status— Result of updating obstacles
Result of updating obstacles, specified as N-element column
vector of ones, zeros, and negative ones. N is the number of
obstacles specified in the
obstacleIDs argument. Each value
indicates whether the obstacle is removed (
1), not found
0), or a duplicate (
-1). If you specify the
same obstacle ID multiple times in the
obstacleIDs input argument,
then all entries besides the last are marked as a duplicate.