请用禁忌搜索算法解决算例,用matlab代码
时间: 2024-10-21 08:07:45 浏览: 64
要使用禁忌搜索算法(Tabu Search, TS)解决给定的物流系统车辆路径优化问题,并提供 MATLAB 代码实现,以下是详细的步骤和代码:
### 1. 问题描述
- **分拨中心**:P (35, 35)
- **客户点**:30个客户点,每个客户点的位置、需求量和服务时间窗口。
- **车辆参数**:
- 车辆数:20辆
- 额定载重量:2000 kg
- 有效服务时长:3.5小时
- 折损成本:50元/小时
- 早到惩罚成本:30元/小时
- 晚到惩罚成本:120元/小时
- 服务时长:10分钟
### 2. 禁忌搜索算法步骤
1. **初始化**:
- 生成初始解(每辆车只服务一个客户点)
- 设置禁忌表长度
- 设置最大迭代次数
2. **邻域搜索**:
- 生成当前解的邻域解
- 选择最佳邻域解
- 更新禁忌表
3. **终止条件**:
- 达到最大迭代次数或最优解长时间未更新
### 3. MATLAB 代码实现
```matlab
function [bestSolution, bestCost] = tabuSearchVRP()
% 参数设置
maxIter = 2000;
tabuLength = 20;
numVehicles = 20;
depot = [35, 35];
customers = [
41, 49, 180, 15, 25;
55, 45, 200, 20, 30;
10, 43, 300, 35, 45;
55, 60, 450, 30, 40;
30, 60, 200, 150, 160;
50, 35, 100, 150, 160;
15, 10, 500, 110, 120;
30, 5, 200, 135, 145;
5, 80, 200, 50, 60;
45, 65, 400, 40, 50;
13, 65, 350, 80, 90;
2, 60, 600, 100, 110;
75, 5, 250, 100, 110;
96, 38, 150, 70, 80;
36, 26, 150, 170, 180;
85, 77, 200, 65, 75;
87, 69, 260, 80, 90;
53, 3, 500, 130, 140;
81, 52, 380, 105, 115;
16, 18, 280, 90, 100;
4, 18, 100, 70, 80;
76, 92, 300, 90, 100;
80, 26, 450, 100, 110;
93, 8, 300, 70, 80;
29, 97, 300, 105, 115;
53, 87, 200, 72, 82;
67, 34, 200, 125, 135;
71, 78, 250, 65, 75;
89, 87, 350, 110, 120;
53, 30, 550, 13, 23
];
% 计算距离矩阵
distMatrix = calculateDistanceMatrix(depot, customers);
% 初始化解
initialSolution = initializeSolution(numVehicles, size(customers, 1));
currentSolution = initialSolution;
bestSolution = initialSolution;
bestCost = calculateTotalCost(currentSolution, distMatrix, customers);
% 禁忌表
tabuList = cell(tabuLength, 1);
for iter = 1:maxIter
% 生成邻域解
neighborhood = generateNeighborhood(currentSolution);
% 选择最佳邻域解
[newSolution, newCost] = selectBestNeighbor(neighborhood, distMatrix, customers, tabuList);
% 更新当前解
if newCost < bestCost
bestSolution = newSolution;
bestCost = newCost;
end
currentSolution = newSolution;
% 更新禁忌表
updateTabuList(tabuList, newSolution);
% 终止条件
if mod(iter, 100) == 0
fprintf('Iteration %d: Best Cost = %.2f\n', iter, bestCost);
end
end
end
function distMatrix = calculateDistanceMatrix(depot, customers)
n = size(customers, 1);
distMatrix = zeros(n+1, n+1);
% 计算分拨中心到所有客户点的距离
for i = 1:n
distMatrix(1, i+1) = norm(depot - customers(i, :));
distMatrix(i+1, 1) = distMatrix(1, i+1);
end
% 计算客户点之间的距离
for i = 1:n
for j = 1:n
if i ~= j
distMatrix(i+1, j+1) = norm(customers(i, :) - customers(j, :));
end
end
end
end
function solution = initializeSolution(numVehicles, numCustomers)
solution = cell(numVehicles, 1);
for i = 1:numVehicles
if i <= numCustomers
solution{i} = i;
else
solution{i} = [];
end
end
end
function neighborhood = generateNeighborhood(solution)
numVehicles = length(solution);
neighborhood = {};
for i = 1:numVehicles
for j = i+1:numVehicles
if ~isempty(solution{i}) && ~isempty(solution{j})
% 交换客户点
temp = solution{i};
solution{i} = solution{j};
solution{j} = temp;
neighborhood{end+1} = solution;
% 插入客户点
for k = 1:length(solution{i})
temp = solution{i};
solution{i}(k) = solution{j}(1);
solution{j}(1) = [];
neighborhood{end+1} = solution;
solution{i} = temp;
end
for k = 1:length(solution{j})
temp = solution{j};
solution{j}(k) = solution{i}(1);
solution{i}(1) = [];
neighborhood{end+1} = solution;
solution{j} = temp;
end
end
end
end
end
function [bestNeighbor, bestCost] = selectBestNeighbor(neighborhood, distMatrix, customers, tabuList)
bestCost = inf;
bestNeighbor = [];
for i = 1:length(neighborhood)
cost = calculateTotalCost(neighborhood{i}, distMatrix, customers);
if cost < bestCost && ~isInTabuList(neighborhood{i}, tabuList)
bestCost = cost;
bestNeighbor = neighborhood{i};
end
end
end
function isInTabu = isInTabuList(solution, tabuList)
isInTabu = false;
for i = 1:length(tabuList)
if isequal(solution, tabuList{i})
isInTabu = true;
return;
end
end
end
function updateTabuList(tabuList, newSolution)
tabuList = circshift(tabuList, 1);
tabuList{1} = newSolution;
end
function totalCost = calculateTotalCost(solution, distMatrix, customers)
totalCost = 0;
numVehicles = length(solution);
for i = 1:numVehicles
if ~isempty(solution{i})
route = [1, solution{i} + 1]; % 加上分拨中心
routeCost = 0;
for j = 1:length(route)-1
routeCost = routeCost + distMatrix(route(j), route(j+1));
end
routeCost = routeCost * 5; % 运输成本
routeCost = routeCost + 80; % 启动成本
% 计算时间和惩罚成本
currentTime = 0;
for j = 2:length(route)-1
currentTime = currentTime + distMatrix(route(j-1), route(j)) / 60; % 行驶时间
currentTime = currentTime + 10 / 60; % 服务时间
startTime = customers(route(j)-1, 3) / 60;
endTime = customers(route(j)-1, 4) / 60;
if currentTime < startTime
routeCost = routeCost + (startTime - currentTime) * 30; % 早到惩罚
elseif currentTime > endTime
routeCost = routeCost + (currentTime - endTime) * 120; % 晚到惩罚
end
end
currentTime = currentTime + distMatrix(route(end-1), route(end)) / 60; % 返回分拨中心时间
if currentTime > 3.5
routeCost = routeCost + (currentTime - 3.5) * 50; % 超时折损成本
end
totalCost = totalCost + routeCost;
end
end
end
```
### 4. 运行代码
将上述代码保存为 `tabuSearchVRP.m` 文件,然后在 MATLAB 中运行 `tabuSearchVRP` 函数即可得到最优解和最小成本。
### 5. 结果分析
- **最优解**:输出的最佳配送方案和总成本。
- **性能评估**:可以通过调整参数(如最大迭代次数、禁忌表长度等)来进一步优化算法性能。
希望这段代码能帮助你解决物流系统车辆路径优化问题!如果有任何问题或需要进一步的帮助,请随时联系我。
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