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(1) 融合混沌映射与反向学习的旗鱼优化算法改进策略
旗鱼优化算法在初始化阶段采用随机生成种群的方式,这种方式虽然简单易行,但往往导致初始种群分布不均匀,部分解空间未能得到有效覆盖,从而影响算法后续的搜索效率和求解精度。为解决这一问题,本研究引入Tent混沌映射来生成初始种群,Tent映射具有遍历性强、分布均匀的特点,能够使初始种群在搜索空间内呈现更加均衡的分布状态。具体实现过程中,首先在解空间的边界范围内生成一个随机种子,然后通过Tent映射的迭代公式不断产生新的混沌序列值,将这些值映射到实际的决策变量范围内,从而构建出初始旗鱼种群和沙丁鱼种群。
在种群进化过程中,为了进一步提升算法跳出局部最优的能力,本研究将反向学习机制嵌入到旗鱼优化算法的位置更新环节。反向学习的核心思想是在当前解的基础上生成其反向解,通过比较当前解与反向解的适应度值来选择更优的个体进入下一代种群。在每次迭代结束后,对种群中一定比例的个体执行反向学习操作,计算其关于搜索空间边界的反向位置,若反向位置对应的适应度值优于原位置,则用反向位置替换原位置。这种机制有效扩大了算法的搜索范围,增加了发现全局最优解的概率。同时,为了避免算法在迭代后期陷入停滞状态,引入柯西变异算子对精英个体进行扰动处理,柯西分布具有较长的尾部特征,能够产生较大的变异步长,帮助算法在收敛后期实现有效的跳跃式搜索。
(2) 具有遗传特性的混沌自适应旗鱼优化算法设计
针对标准旗鱼优化算法在处理复杂多峰函数时容易出现早熟收敛的问题,本研究设计了一种融合遗传算法思想的混沌自适应旗鱼优化算法。该算法在保留旗鱼优化算法狩猎行为模拟框架的基础上,引入选择、交叉和变异三种遗传操作来增强种群的多样性。在选择操作中,采用锦标赛选择策略从当前种群中挑选优秀个体,这种策略既保证了优良基因的传递,又避免了过度选择压力导致的种群多样性丧失。交叉操作采用自适应交叉概率控制机制,在迭代初期设置较高的交叉概率以促进种群间的信息交换,在迭代后期逐步降低交叉概率以保护已发现的优质解结构。
在算法参数的自适应调节方面,本研究设计了基于迭代进程的攻击系数动态调整策略。攻击系数是控制旗鱼向沙丁鱼逼近速度的关键参数,传统算法采用固定的线性递减方式,无法根据种群的实际进化状态进行灵活调整。改进后的自适应攻击系数综合考虑当前迭代次数、种群平均适应度变化率以及最优个体适应度改进幅度等因素,当种群整体适应度提升较快时,适当减小攻击系数以加强局部精细搜索;当种群适应度停滞不前时,增大攻击系数以扩大搜索范围寻找新的有利区域。此外,在沙丁鱼位置更新公式中引入Logistic混沌扰动项,使沙丁鱼在躲避旗鱼攻击时产生更加多样化的逃逸路径,从而带动整个种群在解空间中进行更充分的探索。
(3) 面向化工动态优化问题的离散化求解方法
化工生产过程中存在大量的动态优化问题,如批式反应器的最优温度控制、连续搅拌反应釜的最优进料策略等,这些问题的目标是寻找随时间变化的最优控制轨迹以使某个性能指标达到最优。本研究将改进的旗鱼优化算法与控制向量参数化方法相结合,形成一套完整的化工动态优化求解框架。控制向量参数化的基本思想是将连续的控制变量时域划分为若干离散区间,在每个区间内用特定的基函数来近似表示控制变量的变化规律,从而将无限维的动态优化问题转化为有限维的参数优化问题。
import numpy as np from scipy.integrate import odeint class ImprovedSailfishOptimizer: def __init__(self, obj_func, dim, pop_size=50, max_iter=500, lb=-100, ub=100): self.obj_func = obj_func self.dim = dim self.pop_size = pop_size self.sardine_size = pop_size * 2 self.max_iter = max_iter self.lb = lb self.ub = ub def tent_chaos_init(self, size): population = np.zeros((size, self.dim)) x = np.random.rand(self.dim) for i in range(size): x = np.where(x < 0.5, 2 * x, 2 * (1 - x)) population[i] = self.lb + x * (self.ub - self.lb) return population def opposition_learning(self, position): return self.lb + self.ub - position def cauchy_mutation(self, position, scale=0.1): cauchy_noise = np.random.standard_cauchy(self.dim) * scale new_position = position + cauchy_noise return np.clip(new_position, self.lb, self.ub) def logistic_chaos(self, x, mu=4.0): return mu * x * (1 - x) def adaptive_attack_coefficient(self, t, fitness_improvement): base_coef = 2 * (1 - t / self.max_iter) adaptive_factor = 1 / (1 + np.exp(-fitness_improvement * 10)) return base_coef * adaptive_factor def optimize(self): sailfish = self.tent_chaos_init(self.pop_size) sardines = self.tent_chaos_init(self.sardine_size) sf_fitness = np.array([self.obj_func(ind) for ind in sailfish]) sd_fitness = np.array([self.obj_func(ind) for ind in sardines]) best_idx = np.argmin(sf_fitness) elite = sailfish[best_idx].copy() elite_fitness = sf_fitness[best_idx] injured_sardine = sardines[np.argmax(sd_fitness)].copy() convergence = [] prev_elite_fitness = elite_fitness for t in range(self.max_iter): fitness_improvement = (prev_elite_fitness - elite_fitness) / (abs(prev_elite_fitness) + 1e-10) A = self.adaptive_attack_coefficient(t, fitness_improvement) prev_elite_fitness = elite_fitness PD = 1 - len(sailfish) / (len(sailfish) + len(sardines)) for i in range(self.pop_size): r = np.random.rand() chaos_factor = self.logistic_chaos(np.random.rand()) if r < PD: sailfish[i] = elite - A * (np.random.rand(self.dim) * (elite + injured_sardine) / 2 - sailfish[i]) else: sailfish[i] = elite - A * np.random.rand(self.dim) * chaos_factor sailfish[i] = np.clip(sailfish[i], self.lb, self.ub) for i in range(self.sardine_size): if np.random.rand() < 0.5: sardines[i] = sardines[i] - A * np.random.rand(self.dim) * (elite - sardines[i] + 0.01) sardines[i] = np.clip(sardines[i], self.lb, self.ub) sf_fitness = np.array([self.obj_func(ind) for ind in sailfish]) sd_fitness = np.array([self.obj_func(ind) for ind in sardines]) if np.random.rand() < 0.3: opp_idx = np.random.randint(0, self.pop_size) opp_solution = self.opposition_learning(sailfish[opp_idx]) opp_solution = np.clip(opp_solution, self.lb, self.ub) opp_fitness = self.obj_func(opp_solution) if opp_fitness < sf_fitness[opp_idx]: sailfish[opp_idx] = opp_solution sf_fitness[opp_idx] = opp_fitness if t > self.max_iter * 0.7: mutant = self.cauchy_mutation(elite, scale=0.05 * (self.ub - self.lb)) mutant_fitness = self.obj_func(mutant) if mutant_fitness < elite_fitness: elite = mutant elite_fitness = mutant_fitness current_best_idx = np.argmin(sf_fitness) if sf_fitness[current_best_idx] < elite_fitness: elite = sailfish[current_best_idx].copy() elite_fitness = sf_fitness[current_best_idx] injured_sardine = sardines[np.argmax(sd_fitness)].copy() convergence.append(elite_fitness) return elite, elite_fitness, convergence def sphere_function(x): return np.sum(x ** 2) def rastrigin_function(x): return 10 * len(x) + np.sum(x ** 2 - 10 * np.cos(2 * np.pi * x)) def chemical_reactor_dynamics(y, t, u, params): Ca, T = y Ca0, T0, k0, E, rho, Cp, deltaH, UA, V = params F = u[0] Tc = u[1] k = k0 * np.exp(-E / (8.314 * T)) dCa = F / V * (Ca0 - Ca) - k * Ca dT = F / V * (T0 - T) + (-deltaH) / (rho * Cp) * k * Ca + UA / (V * rho * Cp) * (Tc - T) return [dCa, dT] if __name__ == "__main__": optimizer = ImprovedSailfishOptimizer(sphere_function, dim=30, pop_size=40, max_iter=300) best_solution, best_fitness, history = optimizer.optimize() print(f"Best fitness: {best_fitness}") print(f"Best solution: {best_solution[:5]}...")如有问题,可以直接沟通
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