我如何解决多个时期EOQ的问题

Question

大家好，我正在尝试解决多个时期的EOQ模型。我用buring_price定义了不媒体约束。因此，如果Q较高，那么价格将会改变，而我面临56号规则部分的错误。

import pyomo.environ as pyo
from pyomo.environ import *
from pyomo.opt import SolverFactory

model = pyo.ConcreteModel()

# Time periods
model.T = pyo.RangeSet(4)

# Parameters during period t
model.D = {1: 15 , 2: 5 , 3: 20 , 4: 40}        # D = Demand
model.C = {1: 20 , 2: 20 , 3: 20 , 4: 20}       # C = Ordering Cost
model.H = {1: 2 , 2: 2 , 3: 2 , 4:2}            # H = Holding Costs


# Variables during period t
model.B = pyo.Var( domain=pyo.NonNegativeReals)             # B = buring price
model.Q = pyo.Var(model.T, domain=pyo.NonNegativeReals)     # Q = Quantity
model.I = pyo.Var(model.T, domain=pyo.NonNegativeReals)     # I = Inventory
I0 = 0                                                      # I0 = Inventory in the first round
Q_List = []                                                 # Q_List = Put the Q value in the list

# Simplifying parameters
T = model.T
Q = model.Q
I = model.I
D = model.D
C = model.C
H = model.H
B = model.B

# Define the inventory relationships
def inventory_Online (m,t) :
    if t == m.T.first() :
        return m.I[t] == (I0 + m.Q[t]) - m.D[t]
    return model.I[t] == (m.I[t-1] + m.Q[t]) - m.D[t]
model.inventory = pyo.Constraint(model.T, rule = inventory_Online)

# Define the cost function
def Obj_rule(m,t) :
    TIC = sum(m.C[t]*m.D[t]/m.Q[t] + m.H[t]*m.I[t] + m.H[t]*m.Q[t]/2 + m.B for t in model.T)
    return TIC
model.Obj = pyo.Objective(rule=Obj_rule , sense=minimize)

# Define the buring_price
def buring_price (m,t):
    for t in model.T:
        if m.Q[t] > 0 and m.Q[t] >=10:
            return m.B == m.Q[t]*10

        elif m.Q[t] > 10 and m.Q[t] <= 100:
            return m.B == m.Q[t]*9

        else:
           return m.B == m.Q[t]*8
model.discount = pyo.Constraint(rule= buring_price)

# Solve the problem
opt = SolverFactory('ipopt',executable='C:\\Ipopt\\bin\\ipopt.exe')
opt.solve(model)

# Print the results
model.pprint()
TIC_Optimal = pyo.value(Obj_rule(model,T))

print('-------------------------TIC Optimal----------------------------------')
print('TIC Optimal =',TIC_Optimal)

print('-------------------------I[t]----------------------------------')
for t in model.T:
    print('Period: {0}, Prod. Amount: {1}'.format(t, pyo.value(model.I[t])))

print('-------------------------Q[t]----------------------------------')
for t in model.T:
    print('Period: {0}, Prod. Amount: {1}'.format(t, pyo.value(model.Q[t])))

print('-------------------------Q[t] List----------------------------------')
for t in model.T:
    Q_List.append(pyo.value(model.Q[t]))
print(Q_List)

我非常感谢帮助我。

错误

错误：规则在生成表达式以进行约束折扣的表达式失败 索引无：pyomoexception：无法将非恒定表达式转换为 布尔。此错误通常是由于布尔中使用表达式引起的 诸如if语句之类的上下文。例如， mx = var（）如果mx＆lt; = 0： ...