python实现基于遗传算法求解混合流水车间调度问题
时间: 2023-08-10 08:00:22 浏览: 192
混合流水车间调度问题是一个经典的生产调度问题,目标是找到一个最优的调度方案,使得所有任务的完成时间最短。
Python可以使用遗传算法求解混合流水车间调度问题。下面是一个简单的实现步骤:
1. 初始化种群:随机生成一组可能的调度方案作为初始种群。每个个体代表一个调度方案,由任务序列构成。
2. 评估适应度:根据每个个体的调度方案,计算其适应度值。适应度值可以根据任务的完成时间来衡量,完成时间越短,适应度值越高。
3. 选择:根据适应度值进行选择操作,选择适应度较高的个体作为父代。
4. 交叉:对选择出的父代进行交叉操作,生成新的个体。交叉操作可以采用交换部分任务序列的方式,生成不同的调度方案。
5. 变异:对交叉生成的个体进行变异操作,引入一定的变异概率。变异操作可以采用随机交换任务位置的方式,引入一定的随机性。
6. 更新种群:将新生成的个体加入种群中,并更新适应度值。
7. 判断停止条件:设定停止条件,例如达到一定的迭代次数或适应度值达到某个阈值。
8. 重复步骤2到步骤7,直到满足停止条件。
通过这样的遗传算法求解,可以得到一个较优的混合流水车间调度方案。
需要注意的是,以上是一个基于遗传算法的简单实现步骤,实际应用中还可以结合其他优化方法和启发式规则进行改进和优化,以进一步提高求解的效果。
相关问题
gui界面遗传算法求解流水车间调度问题设计 python
遗传算法是一种常用的优化算法,可以用于求解流水车间调度问题。下面是一个使用 Python 的 Tkinter 模块设计的 GUI 界面,可以通过遗传算法求解流水车间调度问题:
```python
import tkinter as tk
import random
import numpy as np
def init_population(pop_size, job_count, machine_count):
# 初始化种群
population = []
for i in range(pop_size):
chromosome = np.zeros((job_count, machine_count), dtype=int)
for j in range(job_count):
chromosome[j] = np.random.permutation(machine_count)
population.append(chromosome)
return population
def fitness(chromosome, processing_times):
# 计算适应度
makespan = np.zeros(len(chromosome), dtype=int)
for i in range(len(chromosome)):
job_times = np.zeros(len(chromosome[i]), dtype=int)
for j in range(len(chromosome[i])):
machine = chromosome[i][j]
job_times[machine] += processing_times[i][machine]
if job_times[machine] > makespan[i]:
makespan[i] = job_times[machine]
return 1.0 / makespan
def selection(population, fitness_values):
# 选择操作
fitness_sum = sum(fitness_values)
probabilities = [fitness_values[i] / fitness_sum for i in range(len(fitness_values))]
selected_indices = np.random.choice(len(population), size=len(population), p=probabilities)
selected_population = [population[i] for i in selected_indices]
return selected_population
def crossover(parent1, parent2):
# 交叉操作
child1 = parent1.copy()
child2 = parent2.copy()
crossover_point = int(len(parent1) / 2)
child1[crossover_point:] = parent2[crossover_point:]
child2[crossover_point:] = parent1[crossover_point:]
return child1, child2
def mutation(chromosome, mutation_prob):
# 变异操作
for i in range(len(chromosome)):
for j in range(len(chromosome[i])):
if random.random() < mutation_prob:
chromosome[i][j] = np.random.randint(len(chromosome[i]))
return chromosome
def genetic_algorithm(pop_size, job_count, machine_count, processing_times, max_generations):
# 遗传算法求解流水车间调度问题
population = init_population(pop_size, job_count, machine_count)
for generation in range(max_generations):
fitness_values = [fitness(chromosome, processing_times) for chromosome in population]
selected_population = selection(population, fitness_values)
new_population = []
for i in range(int(pop_size / 2)):
parent1 = random.choice(selected_population)
parent2 = random.choice(selected_population)
child1, child2 = crossover(parent1, parent2)
child1 = mutation(child1, 0.1)
child2 = mutation(child2, 0.1)
new_population.append(child1)
new_population.append(child2)
population = new_population
best_chromosome = max(population, key=lambda c: fitness(c, processing_times))
return best_chromosome
class Application(tk.Frame):
def __init__(self, master=None):
super().__init__(master)
self.master = master
self.pack()
self.create_widgets()
def create_widgets(self):
# 创建控件
self.job_count_label = tk.Label(self, text="作业数量")
self.job_count_label.grid(row=0, column=0)
self.job_count_entry = tk.Entry(self)
self.job_count_entry.grid(row=0, column=1)
self.machine_count_label = tk.Label(self, text="机器数量")
self.machine_count_label.grid(row=1, column=0)
self.machine_count_entry = tk.Entry(self)
self.machine_count_entry.grid(row=1, column=1)
self.processing_times_label = tk.Label(self, text="加工时间矩阵")
self.processing_times_label.grid(row=2, column=0)
self.processing_times_text = tk.Text(self, height=10, width=30)
self.processing_times_text.grid(row=2, column=1)
self.run_button = tk.Button(self, text="运行", command=self.run)
self.run_button.grid(row=3, column=0)
self.result_label = tk.Label(self, text="结果")
self.result_label.grid(row=3, column=1)
self.quit_button = tk.Button(self, text="退出", command=self.master.destroy)
self.quit_button.grid(row=4, column=1)
def run(self):
# 运行遗传算法求解流水车间调度问题
job_count = int(self.job_count_entry.get())
machine_count = int(self.machine_count_entry.get())
processing_times = [list(map(int, row.split())) for row in self.processing_times_text.get("1.0", "end").split("\n") if row.strip()]
best_chromosome = genetic_algorithm(50, job_count, machine_count, processing_times, 100)
self.result_label.configure(text=str(best_chromosome))
# 创建主窗口
root = tk.Tk()
# 设置窗口标题
root.title("流水车间调度问题求解")
# 创建应用程序
app = Application(master=root)
# 进入消息循环
app.mainloop()
```
这个程序创建了一个 GUI 界面,包含作业数量、机器数量和加工时间矩阵三个输入框,以及一个运行按钮和一个结果标签。你可以输入作业数量、机器数量和加工时间矩阵,然后点击运行按钮,程序将使用遗传算法求解流水车间调度问题,并在结果标签中显示最优解的染色体。
遗传算法求解车间调度问题python
遗传算法可以用来求解车间调度问题。下面是一个使用Python实现的简单示例代码:
```python
import random
# 初始化种群
def init_population(population_size, gene_size):
population = []
for _ in range(population_size):
chromosome = [i+1 for i in range(gene_size)]
random.shuffle(chromosome)
population.append(chromosome)
return population
# 计算染色体适应度
def calculate_fitness(chromosome):
fitness = 0
for i in range(len(chromosome)-1):
if chromosome[i] != chromosome[i+1]:
fitness += 1
return fitness
# 选择操作
def selection(population):
fitness_values = [calculate_fitness(chromosome) for chromosome in population]
total_fitness = sum(fitness_values)
probabilities = [fitness/total_fitness for fitness in fitness_values]
selected_chromosomes = random.choices(population, probabilities, k=len(population))
return selected_chromosomes
# 交叉操作
def crossover(parent1, parent2):
point = random.randint(0, len(parent1)-1)
child1 = parent1[:point] + parent2[point:]
child2 = parent2[:point] + parent1[point:]
return child1, child2
# 变异操作
def mutation(chromosome):
point1, point2 = random.sample(range(len(chromosome)), 2)
chromosome[point1], chromosome[point2] = chromosome[point2], chromosome[point1]
return chromosome
# 遗传算法求解车间调度问题
def solve_job_shop_scheduling(population_size, gene_size, max_generations):
population = init_population(population_size, gene_size)
best_fitness = float('inf')
best_chromosome = None
for generation in range(max_generations):
selected_chromosomes = selection(population)
new_population = []
while len(new_population) < population_size:
parent1, parent2 = random.sample(selected_chromosomes, 2)
child1, child2 = crossover(parent1, parent2)
child1 = mutation(child1)
child2 = mutation(child2)
new_population.extend([child1, child2])
population = new_population
for chromosome in population:
fitness = calculate_fitness(chromosome)
if fitness < best_fitness:
best_fitness = fitness
best_chromosome = chromosome
print(f"Generation {generation+1}: Best Fitness = {best_fitness}")
return best_chromosome
# 示例使用
population_size = 100
gene_size = 10
max_generations = 100
best_chromosome = solve_job_shop_scheduling(population_size, gene_size, max_generations)
print("Best Chromosome:", best_chromosome)
```
这是一个简单的遗传算法示例,用于求解车间调度问题。其中,种群的大小、基因的大小以及最大迭代次数可以根据具体问题进行调整。代码中的适应度函数根据车间调度问题的实际需求进行定义和修改。
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