drawing path

This commit is contained in:
Lucas MARAIS 2023-12-03 18:05:14 +01:00
parent 17ed7458bf
commit 7cfd0e5750
3 changed files with 195 additions and 9 deletions

78
IsIntersecting.m Normal file
View File

@ -0,0 +1,78 @@
function intersect = IsIntersecting (L1, L2, closestPoint, newPoint)
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% function path = buildRRT(L1, L2, start, finish)
% Task: Determine the 3D transformation matrix corresponding to a set of Denavit-Hartenberg parameters
%
% Inputs:
% - L1: first length
% - L2: second length
% - closestPoint: start point x y
% - newPoint: end point x y
%
% Output:
% -path: Vector of points
%
% author: Marais Lucas
% date: 22/11/2023
x3 = [-L2 -L2 L2 L2];
y3 = [-L2 L2 L2 -L2];
x1 = [-L1-L2 -L1-L2 L1+L2 L1+L2];
y1 = [-L1-L2 L1+L2 L1+L2 -L1-L2];
x2 = [-L1-L2 -L1-L2 L1+L2 L1+L2];
y2 = [-L1 L1 L1 -L1];
% checks if the path is crossed by an obstacle
crossesObstacle = false;
for i = 1:length(x1)
edge1 = [x1(i), y1(i), x1(mod(i, 4) + 1), y1(mod(i, 4) + 1)];
edge2 = [x2(i), y2(i), x2(mod(i, 4) + 1), y2(mod(i, 4) + 1)];
edge3 = [x3(i), y3(i), x3(mod(i, 4) + 1), y3(mod(i, 4) + 1)];
% Check if the line intersects with any obstacle edge
if doIntersect(closestPoint, newPoint, edge1(1:2), edge1(3:4)) || ...
doIntersect(closestPoint, newPoint, edge2(1:2), edge2(3:4)) || ...
doIntersect(closestPoint, newPoint, edge3(1:2), edge3(3:4))
crossesObstacle = true;
break;
end
end
% Return the result
intersect = crossesObstacle;
endfunction
function intersects = doIntersect(p1, q1, p2, q2)
% Function to check if two line segments (p1, q1) and (p2, q2) intersect
if (p1 == q1) || (p2 == q2)
intersects = false; % Degenerate cases, no intersection
return;
end
% Check if the line segments are not collinear
if orientation(p1, q1, p2) ~= orientation(p1, q1, q2) && ...
orientation(p2, q2, p1) ~= orientation(p2, q2, q1)
intersects = true;
return;
end
intersects = false; % No intersection
end
function o = orientation(p, q, r)
% Function to find the orientation of triplet (p, q, r)
% Returns:
% 0 -> Collinear points
% 1 -> Clockwise points
% 2 -> Counterclockwise points
val = (q(2) - p(2)) * (r(1) - q(1)) - (q(1) - p(1)) * (r(2) - q(2));
if val == 0
o = 0; % Collinear
elseif val > 0
o = 1; % Clockwise
else
o = 2; % Counterclockwise
end
end

View File

@ -1,6 +1,6 @@
function path = buildRRT(L1, L2, x1, y1, x2, y2)
function path = buildRRT(L1, L2, pt1, pt2)
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% function path = buildPRM(L1, L2)
% function path = buildRRT(L1, L2, start, finish)
% Task: Determine the 3D transformation matrix corresponding to a set of Denavit-Hartenberg parameters
%
% Inputs:
@ -25,17 +25,23 @@ function path = buildRRT(L1, L2, x1, y1, x2, y2)
y1 = [-L1-L2 L1+L2 L1+L2 -L1-L2];
x2 = [-L1-L2 -L1-L2 L1+L2 L1+L2];
y2 = [-L1 L1 L1 -L1];
xy_valid = []
xy_valid(end+1,:) = pt1
q1q2_valid = [];
validLinks = [];
distanceBetweenPoints = 0.1;
fill(x1, y1, 'r');
hold on;
done = 1;
if ~(IsIntersecting (L1, L2, pt1, pt2))
xy_valid(end+1,:) = pt2;
validLinks(end+1,:) = [1 2];
done = 0
endif
t = linspace(0, 2*pi, 100)';
r=L1+L2;
@ -47,8 +53,107 @@ function path = buildRRT(L1, L2, x1, y1, x2, y2)
plot(circsx, circsy, 'b');
hold on;
fill(x3, y3, 'b');
fill(x3, y3, 'r');
hold on;
axis equal;
while(done == 1)
% samples randomly the joint space
q1 = rand()*360.0;
q2 = rand()*360.0;
% creates the DH table
theta = [q1; q2];
d = [0; 0];
a = [L1; L2];
alpha = [0; 0];
% computes the FK
wTee = dh2ForwardKinematics(theta, d, a, alpha, 1);
% determines the position of the end-effector
position_ee = wTee(1:2,end);
%determine the closest point
min = 12345678901234567890;
closestPoint = [];
closestPointIdx = 0;
for i=1:size(xy_valid,1)
dist = (position_ee(1)-xy_valid(i,1))^2+ (position_ee(2)-xy_valid(i,2))^2;
if (dist < min)
min = dist;
closestPoint = xy_valid(i, :);
closestPointIdx = i;
endif
endfor
min = 12345678901234567890;
%place the point at a given length
vectorForce = [position_ee(1)-closestPoint(1,1) position_ee(2)-closestPoint(1,2)];
% Calculate the Euclidean norm (length) of the vector
vectorNorm = norm(vectorForce);
% Normalize the vector
vectorForce = vectorForce / vectorNorm;
newPoint = closestPoint+vectorForce*distanceBetweenPoints;
plot(newPoint(1), newPoint(2), 'b');
% checks if the end-effector is not hitting any obstacle
eeHittingObstacle = 0;
if (newPoint(2) >= L1)
eeHittingObstacle = 1;
end
if (newPoint(2) <= -L1)
eeHittingObstacle = 1;
end
if (newPoint(1) >= -L2 && newPoint(1) <= L2 && newPoint(2) >= -L2 && newPoint(2) <= L2)
eeHittingObstacle = 1;
end
% If the there is something wrong don't do
if ~(IsIntersecting (L1, L2, closestPoint, newPoint) || eeHittingObstacle == 1)
validLinks(end+1,:) = [closestPointIdx length(xy_valid)+1];
xy_valid(end+1,:) = newPoint;
q1q2_valid(end+1,:) = theta;
endif
%no more obstacles
if ~(IsIntersecting (L1, L2, newPoint, pt2) || eeHittingObstacle == 1)
done = 0
xy_valid(end+1,:) = pt2;
validLinks(end+1,:) = [closestPointIdx length(xy_valid)];
endif
end
visibilityGraph = zeros(length(xy_valid));
% Add edges to visibility graph based on valid links
for i = 1:length(xy_valid)
for j = i+1:length(xy_valid)
if ~IsIntersecting(L1, L2, xy_valid(i, :), xy_valid(j, :))
% If the line segment between points i and j does not intersect with obstacles
visibilityGraph(i, j) = norm(xy_valid(i, :) - xy_valid(j, :));
visibilityGraph(j, i) = visibilityGraph(i, j); % Assuming undirected graph
else
visibilityGraph(i, j) = NaN;% No links
visibilityGraph(j, i) = visibilityGraph(i, j); % Assuming undirected graph
end
end
end
[distanceToNode, parentOfNode, nodeTrajectory] = dijkstra(length(xy_valid)-2, visibilityGraph);
nodeTrajectory = [1 nodeTrajectory];
nodeTrajectory(end) = length(xy_valid)
for i=1:length(nodeTrajectory)-1
x = [xy_valid(nodeTrajectory(i),1) xy_valid(nodeTrajectory(i+1),1)]
y = [xy_valid(nodeTrajectory(i),2) xy_valid(nodeTrajectory(i+1),2)]
plot(x, y)
endfor
path = nodeTrajectory;
end

5
test.m
View File

@ -1,2 +1,5 @@
path = buildPRM(2, 1)
path = buildRRT(2, 1, [-1.5 -1.5], [1.5 1.5])
%test for intersections
intersect = IsIntersecting (2, 1, [-1.5 1.5], [1.5 1.5])
intersect = IsIntersecting (2, 1, [-1.5 -1.5], [1.5 1.5])