想要基于栅格法的蚁群算法的路径规划的matlab代码
时间: 2023-07-28 22:06:29 浏览: 99
以下是基于栅格法的蚁群算法的路径规划的 Matlab 代码:
```
% 定义地图和起点、终点
map = [0 0 0 0 0 0 0 0 0 0;
0 1 1 1 0 1 0 0 0 0;
0 0 0 1 0 1 0 1 0 0;
0 1 0 0 0 1 0 1 0 0;
0 1 1 1 1 1 1 1 1 0;
0 1 0 0 0 0 0 0 1 0;
0 1 0 1 1 1 1 0 1 0;
0 1 0 0 0 0 0 0 1 0;
0 1 1 1 1 1 1 1 1 0;
0 0 0 0 0 0 0 0 0 0];
startPoint = [2,2];
endPoint = [9,9];
% 初始化蚂蚁群
antCount = 20;
antPosition = repmat(startPoint, antCount, 1);
pheromone = zeros(size(map));
alpha = 1;
beta = 5;
Q = 1;
evaporationRate = 0.5;
maxIteration = 100;
% 迭代寻找最短路径
for iteration = 1:maxIteration
% 遍历所有蚂蚁,更新蚂蚁位置
for ant = 1:antCount
currentPosition = antPosition(ant,:);
while ~isequal(currentPosition, endPoint)
% 计算当前位置周围的邻居节点
neighbors = [];
for i = -1:1
for j = -1:1
if i ~= 0 || j ~= 0
neighborPosition = currentPosition + [i,j];
if neighborPosition(1) >= 1 && neighborPosition(1) <= size(map,1) && ...
neighborPosition(2) >= 1 && neighborPosition(2) <= size(map,2) && ...
map(neighborPosition(1), neighborPosition(2)) == 0
neighbors(end+1,:) = neighborPosition;
end
end
end
end
% 计算当前位置到邻居节点的转移概率
transitionProbability = zeros(size(neighbors,1), 1);
for i = 1:size(neighbors,1)
neighborPosition = neighbors(i,:);
if pheromone(neighborPosition(1), neighborPosition(2)) > 0
transitionProbability(i) = pheromone(currentPosition(1), currentPosition(2))^alpha * ...
(1/distance(currentPosition, neighborPosition))^beta;
else
transitionProbability(i) = 0;
end
end
transitionProbability = transitionProbability/sum(transitionProbability);
% 选择下一个位置
cumProbability = cumsum(transitionProbability);
randomValue = rand;
for i = 1:size(cumProbability,1)
if randomValue <= cumProbability(i)
currentPosition = neighbors(i,:);
break;
end
end
% 更新蚂蚁位置
antPosition(ant,:) = currentPosition;
end
end
% 计算每只蚂蚁的路径长度和贡献度
pathLength = zeros(antCount, 1);
contribution = zeros(size(map));
for ant = 1:antCount
pathLength(ant) = distance(startPoint, antPosition(ant,:));
for i = 1:size(antPosition,1)
contribution(antPosition(i,1), antPosition(i,2)) = contribution(antPosition(i,1), antPosition(i,2)) + Q/pathLength(ant);
end
end
% 更新信息素
pheromone = (1-evaporationRate).*pheromone + contribution;
% 如果找到终点,提前结束迭代
if any(ismember(antPosition, endPoint, 'rows'))
break;
end
end
% 输出最短路径
currentPosition = startPoint;
shortestPath = [currentPosition];
while ~isequal(currentPosition, endPoint)
neighbors = [];
for i = -1:1
for j = -1:1
if i ~= 0 || j ~= 0
neighborPosition = currentPosition + [i,j];
if neighborPosition(1) >= 1 && neighborPosition(1) <= size(map,1) && ...
neighborPosition(2) >= 1 && neighborPosition(2) <= size(map,2) && ...
map(neighborPosition(1), neighborPosition(2)) == 0
neighbors(end+1,:) = neighborPosition;
end
end
end
end
cumProbability = zeros(size(neighbors,1), 1);
for i = 1:size(neighbors,1)
if ismember(neighbors(i,:), shortestPath, 'rows')
cumProbability(i) = 0;
else
cumProbability(i) = pheromone(currentPosition(1), currentPosition(2))^alpha * ...
(1/distance(currentPosition, neighbors(i,:)))^beta;
end
end
cumProbability = cumProbability/sum(cumProbability);
cumProbability = cumsum(cumProbability);
randomValue = rand;
for i = 1:size(cumProbability,1)
if randomValue <= cumProbability(i)
currentPosition = neighbors(i,:);
shortestPath(end+1,:) = currentPosition;
break;
end
end
end
% 绘制地图和最短路径
figure();
hold on;
for i = 1:size(map,1)
for j = 1:size(map,2)
if map(i,j) == 1
rectangle('Position', [j-1, size(map,1)-i, 1, 1], 'FaceColor', 'k');
end
end
end
plot(startPoint(2)-0.5, size(map,1)-startPoint(1)+0.5, 'ro', 'MarkerFaceColor', 'r');
plot(endPoint(2)-0.5, size(map,1)-endPoint(1)+0.5, 'gx', 'MarkerFaceColor', 'g');
shortestPathX = shortestPath(:,2)-0.5;
shortestPathY = size(map,1)-shortestPath(:,1)+0.5;
plot(shortestPathX, shortestPathY, 'b--', 'LineWidth', 2);
xlim([0, size(map,2)]);
ylim([0, size(map,1)]);
axis equal;
```
在这个代码中,我们首先定义了地图和起点、终点。然后,我们初始化了一个包含多只蚂蚁的蚂蚁群,并定义了信息素、alpha、beta、Q、蒸发速率以及最大迭代次数等参数。接下来,我们开始迭代寻找最短路径。在每次迭代中,我们首先遍历所有蚂蚁,更新它们的位置。然后,我们计算每只蚂蚁的路径长度和贡献度,并根据它们的贡献度更新信息素。最后,我们根据信息素和路径长度计算每个邻居节点的转移概率,选择下一个位置,并更新蚂蚁的位置。如果找到了终点,就提前结束迭代。最后,我们输出最短路径并绘制地图和最短路径。
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