单车场多送货点车辆路径问题的改进遗传算法

针对单车场多送货点容量约束的车辆路径问题提出了一种改进的遗传算法。该算法基于自然数编码的染色体,采用了改进的交叉和变异法、内部扰动和外部扰动等技术,提高了遗传算法的优化效率和优化效果。介绍了此算法的原理,给出了具有两个代表性算例试验结果和结果分析。试验结果表明了该改进遗传算法对求解单车场多送货点容量约束的车辆路径问题的有效性。     

一类约束优化问题的改进遗传算法

遗传算法是一种解决非线性无约束优化问题的搜索算法，对于约束优化问题通常采用罚函数法；所提出了的改进算法很好地解决了一类带有凸约束的非红性优化问题。数值结果说明该方法效果较好。     

基于神经网络建模和遗传算法的重油脱盐系统优化研究

概述了重油脱盐系统的BP神经网络建模以及基于遗传算法的系统优化过程，将遗传算法与惩罚函数法相结合应用于约束优化的问题，改善了遗传算法的局限性。同时为了将不等式约束优化问题转化为单目标优化问题，对惩罚函数法进行了改进。结果表明：此方法可以有效解决静电脱盐问题。     

基于遗传算法的飞机定检离位工作流程优化

首次将遗传算法(GA)应用于飞机定检离位工作流程优化中。本文借鉴关键路线法思想建立离位工作流程多约束优化模型,根据可行解变换法思想设计编码和解码方法,并采用经过模拟退火算子和精英选择算子改进后的GA求解。仿真结果表明,在解决多约束优化问题上,改进遗传算法的最优解搜索能力较基本遗传算法有明显提高;优化后离位工作完成时间较优化前缩短14.70%,验证GA在解决定检离位工作流程优化问题上的适用性。     

基于工艺特征约束的改进遗传算法

为提高飞机装配的精度,减小定位的误差,优化具有复杂工艺特征的机身框件的支撑序列.针对优化中工艺特征约束处理问题,建立了工艺特征约束的广义数学模型,从理论角度提出了一种针对此类约束的不可行解修补算法,并基于此算法设计一种改进的遗传算法.使用改进的遗传算法优化某型飞机机身框在可重构柔性工装上的支撑序列,优化过程稳定,最优序列下框的柔性定位误差减小93.08%,保证了飞机装配的精度.理论基础分析和仿真结果分析表明,改进的遗传算法通用性强,适用于各种约束优化问题;收敛速度快且稳定,具备可行性.     

基于改进遗传算法的可靠性网络优化设计

在可靠性条件约束下,使网络成本最低是网络规划NP-hard问题。从遗传算法的基本原理出发并对其进行改进,分析带有可靠性约束条件的通信网设计中的网络优化问题,这一方法的最大优点是可将其推广到求解一般带有约束的网络优化问题。而且结果表明无论是解的精度还是运算速度遗传算法都优于分枝定界法及其它启发式算法。     

基于混合并行遗传算法的多目标约束优化技术研究

多目标约束优化问题属于NP问题。并行遗传算法是解决该类问题的常用算法,它具有较强的全局搜索能力和并行性,但局部搜索能力差,禁忌搜索算法则比较适合于局部搜索。提出了一种基于混合并行遗传算法的多目标约束优化方法,该方法综合了并行遗传算法和禁忌搜索算法的优势,改进了并行遗传算法的性能,能有效避免局部最优解。     

一种新的求解约束多目标优化问题的遗传算法

由于采用罚函数法将有约束多目标优化问题转化为无约束多目标优化问题会使求解不合理,因此,文章首先在无约束Pareto排序遗传算法的基础上,提出了一个简单、实用的能分别考虑目标函数和约束函数,而又可以避免采用罚函数的全新排序方法。接着,针对小生境技术在遗传后期依旧会出现遗传漂移现象和共享半径不易确定等缺陷,提出了一种易于实现的超量惩罚策略来替代小生境技术,用以改进种群的多样性。此外,还采用了Pareto解集过滤器、邻域变异和群体重组等策略对算法的寻优能力进行改进,并最终形成了一种求解有约束多目标优化问题的Pareto遗传算法(CMOPGA),还给出了具体的算法流程图。最后采用两个数值算例对算法的求解性能进行了测试。数值试验表明,采用CMOPGA可方便地求得问题的Pareto前沿,并能使求得的Pareto最优解集具有可靠、均布、多样等特点。     

超混沌遗传算法在多约束QoS组播路由中的应用研究

针对多约束QoS组播路由的优化问题,提出了一种超混沌遗传混沌算法.该算法利用遗传算法中的改进的适应度函数,通过结合超混沌映射优越性的搜索能力,对遗传算法选出的个体进行混沌优化,以改善遗传算法过早陷入早熟的情况.通过仿真实验表明,该算法有效地改进了搜索效率,且收敛速度更快更稳定,是一种解决多约束QoS路由问题可行和有效的方法.     

采用不可微精确罚函数的约束优化演化算法

针对多数已有的采用罚函数的约束优化遗传算法存在优化效果差的问题 ,提出了一种新的求解约束优化问题的演化算法 .借助不可微精确罚函数把约束问题转化为单个无约束问题来处理 .采用混合杂交和间歇变异来提高算法的搜索能力 .数值实验结果表明了新算法的优化效果远远优于已有的几种采用罚函数的遗传算法     

Model of an integrated intelligent design and manufacturing system

The expert system STATEXS is presented for dimensioning, optimization and manufacture of gears and gearings. The optimum dimensions of the gearing were determined using genetic algorithms, well suited to such problems especially because of their robustness and their ability to detect global extremes. After completion of the calculations and optimization of the gears or gear pairs, there follows one of the most difficult operations, the manufacture of the product with theoretically determined and optimized properties. To this end we have also started to use the genetic algorithm approach for the manufacture of various products with demanding shapes.     

Parallel genetic algorithms: a survey and problem state of the art

In relation with development of computer capabilities and the appearance of multicore processors, parallel computing made it possible to reduce the time for solution of optimization problems. At present of interest are methods of parallel computing for genetic algorithms using the evolutionary model of development in which the main component is the population of species (set of alternative solutions to the problem). In this case, the algorithm efficiency increases due to parallel development of several populations. The survey of basic parallelization strategies and the most interesting models of their implementation are presented. Theoretical ideas on improvement of existing parallelization mechanisms for genetic algorithms are described. A modified model of parallel genetic algorithm is developed. Since genetic algorithms are used for solution of optimization problems, the proposed model was studied for the problem of optimization of a multicriteria function. The algorithm capabilities of getting out of local optima and the influence of algorithm parameters on the deep extremum search dynamics were studied. The conclusion on efficiency of application of dynamic connections of processes, rather than static connections, is made. New mechanisms for implementation and analysis of efficiency of dynamic connections for distributed computing in genetic algorithms are necessary.     

Interior ballistic charge design based on a modified particle swarm optimizer

According to the limitation of the interior ballistic charge design with genetic algorithms and some other direct optimization methods, which has complex evolution operators such as crossover and mutation or has poor perferance in solution accuracy and speed, a modified particle swarm optimizer is proposed which is based on a geometrical way and a fuzzy multi-objective optimization. The modified particle swarm optimizer is used to both single-objective and multi-objective optimization problems of interior ballistic charge design for a guided projectile. The solution results show that the modified particle swarm optimizer has a better convergence rate and accuracy than the original particle swarm optimizer and other ever used optimization methods. Combined with deterred propellant technique, the interior ballistic charge design for a guided projectile is optimized by the modified particle swarm optimizer. The optimization results improve the interior ballistic performance and launch safety and provide theoretical direction for the interior ballistic charge design of guided projectile.     

改进非支配排序精英遗传算法的篦冷机参数优化

为优化篦冷机控制参数,提高换热效率,将传热和粘性耗散引起的修正熵产数分别作为目标函数,利用遗传算法对篦冷机参数进行多目标优化.为增加多目标遗传算法的种群多样性,提高算法的局部搜索能力,对传统的非支配排序精英遗传算法(NSGA-Ⅱ)进行部分功能改进.构建多种群、多交叉算子的操作模式,根据子种群对最优解集的贡献量自适应调节子种群规模,利用局部搜索算法提高算法的局部搜索能力.通过标准多目标优化问题验证所提出算法的有效性,并根据优化得到的篦冷机熵产数的最优解集,给出冷却风机功率最小的最优控制方案,通过与生产线的实际数据进行对比验证其优化效果.     

基于微分进化算法的非对称弧齿锥齿轮约束多目标优化

根据齿轮啮合原理和现代摩擦学理论,建立了以弧齿锥齿轮传动齿面上瞬时接触线方向与相对滑动速度之间夹角的余切值最小、传动总体积最小和齿面诱导法曲率主值最小为目标函数的约束多目标优化设计数学模型。对当前的微分进化多目标优化算法进行了改进,给出了适用于工程领域的微分进化约束多目标优化算法。借助于改进的微分进化多目标优化算法,通过范例对弧齿锥齿轮传动进行两目标和三目标优化设计。分析了齿面上瞬时接触线方向与相对滑动速度之间的夹角及齿面诱导法曲率主值对齿面接触强度和胶合强度的影响。     

基于自适应权重和莱维飞行的改进海鸥优化算法

在齿轮系设计问题中, 传统算法存在计算复杂与精度低等缺点, 海鸥优化算法(SOA)得益于其算法原理简单、通用性强、参数少等特性, 现多用于工程设计问题. 然而, 标准海鸥优化算法易出现寻优精度低、搜索速度慢等问题, 本文提出一种混合策略改进的海鸥优化算法(WLSOA). 首先, 利用非线性递减策略增强海鸥优化算法的探索开发能力, 提高寻优精度. 其次, 在海鸥攻击阶段引入自适应权重平衡全局与局部的搜索能力和加入莱维飞行步长对当前最优解进行扰动, 提高算法跳出局部最优值的能力. 然后分别使用WLSOA、黄金正弦算法、鲸鱼优化算法、粒子群优化算法、传统海鸥优化算法及最新提出的改进海鸥优化算法, 通过在9个经典的测试函数上进行仿真实验来探究WLSOA的性能. 结果表明, WLSOA比其他6种算法寻优精度更高, 收敛速度更快. 最后, 在齿轮系设计问题上, 通过与其他13种常见的群智能算法的比较表明, WLSOA的求解性能优于其他算法.     

求解0-1整数规划的混合粒子群优化算法

经典的粒子群是一个有效的寻找连续函数极值的方法,结合遗传算法的思想提出的混合粒子群算法来解决0-1整数规划问题,经过比较测试,6种混合粒子群算法的效果都比较好,特别交叉策略A和变异策略C的混合粒子群算法是最好的且简单有效的算法.对于目前还没有好的解法的组合优化问题,很容易地修改此算法就可解决.     

Multi-objective optimization of two stage thermoelectric cooler using a modified teaching–learning-based optimization algorithm

Teaching–learning-based optimization (TLBO) is a recently developed heuristic algorithm based on the natural phenomenon of teaching–learning process. In the present work, a modified version of the TLBO algorithm is introduced and applied for the multi-objective optimization of a two stage thermoelectric cooler (TEC). Two different arrangements of the thermoelectric cooler are considered for the optimization. Maximization of cooling capacity and coefficient of performance of the thermoelectric cooler are considered as the objective functions. An example is presented to demonstrate the effectiveness and accuracy of the proposed algorithm. The results of optimization obtained by using the modified TLBO are validated by comparing with those obtained by using the basic TLBO, genetic algorithm (GA), particle swarm optimization (PSO) and artificial bee colony (ABC) algorithms.     

二级减速器齿轮传动性能分析和修形优化设计

为改善齿轮传动性能,分析某二级减速器齿轮的静强度、载荷分布和传递误差,发现其低速齿轮副的载荷分布偏载和传递误差相对较大。选取遗传算法V2,结合Romax Designer,对比分析几种齿廓修形与齿向修形的组合方式,其中最好的修形方式是将齿向鼓形修形和齿向斜度修形相结合。采取该方式对齿轮副进行优化,优化后低速齿轮副的传递误差比修形前减小92.41%,齿轮载荷分布得到改善,低速齿轮副的单位载荷降低,齿轮副的可靠性和使用寿命均提高。齿轮修形优化后的减速器传动更平稳,振动和噪声减小。     

Hybrid multi-objective shape design optimization using Taguchi’s method and genetic algorithm

This research is based on a new hybrid approach, which deals with the improvement of shape optimization process. The objective is to contribute to the development of more efficient shape optimization approaches in an integrated optimal topology and shape optimization area with the help of genetic algorithms and robustness issues. An improved genetic algorithm is introduced to solve multi-objective shape design optimization problems. The specific issue of this research is to overcome the limitations caused by larger population of solutions in the pure multi-objective genetic algorithm. The combination of genetic algorithm with robust parameter design through a smaller population of individuals results in a solution that leads to better parameter values for design optimization problems. The effectiveness of the proposed hybrid approach is illustrated and evaluated with test problems taken from literature. It is also shown that the proposed approach can be used as first stage in other multi-objective genetic algorithms to enhance the performance of genetic algorithms. Finally, the shape optimization of a vehicle component is presented to illustrate how the present approach can be applied for solving multi-objective shape design optimization problems.