这个问题可以建模为一维切割库存问题(1D Cutting Stock Problem)的变种,需要同时考虑宽度和高度两个维度的切割。以下是Python解决方案框架: ```python import numpy as np from itertools import product from ortools.linear_solver import pywraplp # 输入数据 orders = [ {'id': 1, 'name': '学校教学楼', 'quantity': 10, 'width': 1.6, 'height': 2.2, 'price': 480}, {'id': 2, 'name': '酒店客房', 'quantity': 20, 'width': 1.8, 'height': 2.4, 'price': 680}, {'id': 3, 'name': '医院病房', 'quantity': 20, 'width': 1.7, 'height': 2.3, 'price': 550}, {'id': 4, 'name': '办公楼', 'quantity': 15, 'width': 1.5, 'height': 2.0, 'price': 420} ] raw_materials = [ {'length': 5.5, 'cost': 18}, {'length': 6.2, 'cost': 22}, {'length': 7.8, 'cost': 28} ] kerf = 0.005 # 锯口宽度 tolerance = 0.01 # 尺寸允许误差 # 预处理:生成所有可能的切割方案 def generate_patterns(): patterns = [] for order in orders: # 计算每个窗框需要的总长度 (2宽度 + 2高度 + 4锯口) total_length = 2*(order['width'] + order['height']) + 4*kerf # 考虑公差范围 min_length = 2*(order['width'] + order['height'] - 2*tolerance) + 4*kerf max_length = 2*(order['width'] + order['height'] + 2*tolerance) + 4*kerf patterns.append({ 'order_id': order['id'], 'min_length': min_length, 'target_length': total_length, 'max_length': max_length, 'price': order['price'] }) return patterns patterns = generate_patterns() # 创建求解器 solver = pywraplp.Solver.CreateSolver('SCIP') # 决策变量 # x[i][j][k]: 使用原材料i切割方案j生产订单k的数量 x = {} for i, material in enumerate(raw_materials): for j in range(len(patterns)): # 每个可能的切割方案 for k, order in enumerate(orders): x[i, j, k] = solver.IntVar(0, order['quantity'], f'x_{i}_{j}_{k}') # 约束条件 # 1. 每个订单的需求满足 for k, order in enumerate(orders): solver.Add(sum(x[i, j, k] for i in range(len(raw_materials)) for j in range(len(patterns)) if patterns[j]['order_id'] == order['id']) >= order['quantity']) # 2. 原材料长度限制 for i, material in enumerate(raw_materials): for j in range(len(patterns)): solver.Add(x[i, j, k] * patterns[j]['max_length'] <= material['length'] for k in range(len(orders))) # 目标函数:最大化利润 profit = sum(x[i, j, k] * patterns[j]['price'] for i in range(len(raw_materials)) for j in range(len(patterns)) for k in range(len(orders))) cost = sum(x[i, j, k] * material['cost'] for i, material in enumerate(raw_materials)) for j in range(len(patterns)) for k in range(len(orders))) solver.Maximize(profit - cost) # 求解 status = solver.Solve() # 输出结果 if status == pywraplp.Solver.OPTIMAL: print('最优解找到') print(f'最大利润: {solver.Objective().Value()}元') # 打印切割方案 for i, material in enumerate(raw_materials): for j in range(len(patterns)): for k in range(len(orders)): if x[i, j, k].solution_value() > 0: print(f'使用{material["length"]}米原材料切割{patterns[j]["order_id"]}号订单的窗框{x[i,j,k].solution_value()}个') else: print('未找到最优解') ``` 这个解决方案的关键点: 1. 将问题转化为一维切割问题,计算每个窗框需要的总长度(2宽度+2高度+锯口) 2. 考虑尺寸公差范围,计算最小和最大允许长度 3. 使用混合整数规划求解器(OR-Tools)寻找最优解 4. 目标函数最大化利润(收入-原材料成本) 实际应用中可能需要: 1. 添加更多切割模式(如一根原材料切割多个窗框) 2. 考虑锯口宽度的精确计算 3. 添加切割顺序约束 4. 处理余料再利用 对于大规模问题,可以考虑列生成算法提高效率。 [2025-04-26 12:09:26 | AI问答 | 1151点数解答]