共查询到20条相似文献,搜索用时 31 毫秒
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The commonly used genetic algorithm (GA) in solving a multi-objective optimization problem (MOOP) is replaced by the hypercube-dividing method (HDM) in this air bearing optimization study. In the new method the dividing of hypercubes in the design space is conducted based on the size and Pareto rank of hypercube. A comparison of the HDM- and GA-based method for the MOOP is performed. The results show that the solution obtained by the HDM is improved with more selections and less computing load. The search in the HDM can also be confined to some useful resolution to improve its global search capability. 相似文献
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针对SQP算法在求解具有复杂约束的间歇过程优化时容易陷入局部极值点的问题,本文提出一种PSO-SQP混合优化算法。该算法首先采用外点罚函数法将间歇过程有约束的优化问题转换为无约束的优化问题,利用PSO强大的全局搜索能力对其进行求解,并把搜索结果作为SQP搜索初始点,以此弥补SQP全局搜索弱的缺点,再利用SQP良好的局部收敛性和较强的非线性收敛速度对原优化问题进行精细搜索,弥补了PSO局部搜索弱的缺点,通过不断的迭代最终获得优化问题的全局最优解。该算法充分利用了SQP和PSO的优缺点,增强了其对复杂约束优化问题的求解能力。将本文提出的算法用于连续搅拌化学反应系统温度控制中,仿真结果表明产物浓度能够充分逼近期望值,且反应器的温度轨迹收敛,从而验证了该算法的有效性和实用价值。 相似文献
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Genetic algorithm (GA), compared to the gradient-based optimization, has advantages of convergence to a global optimized solution.
The genetic algorithm requires so many number of analyses that may cause high computational cost for genetic search. This
paper proposes a personal computer network programming based on TCP/IP protocol and client-server model using socket, to improve
processing speed of the genetic algorithm for optimization of composite laminated structures. By distributed processing for
the generated population, improvement in processing speed has been obtained. Consequently, usage of network-based genetic
algorithm with the faster network communication speed will be a very valuable tool for the discrete optimization of large
scale and complex structures requiring high computational cost. 相似文献
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基于遗传算法难以保持群体的多样性及存在易早熟、效率低的缺陷,提出免疫遗传算法应用于不规则零件排样的优化方法。该算法在遗传算法的全局随机搜索基础上,借鉴了人工免疫系统中的免疫记忆和浓度机制。通过疫苗接种实现种群个体中基因位的局部调整优化,并将其优良个体保存于免疫记忆库中,提高了算法的搜索速度。同时浓度机制保证了遗传交叉和变异过程中生成下代种群个体的多样性,扩大了搜索空间,更利于最优解的获取。该方法在开发的不规则件排样系统中进行了实算求解,通过与标准遗传算法的实验结果比对,板材的利用效率得到显著提高。 相似文献
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The study deals with the development of a hybrid search algorithm for efficient optimization of porous air bearings. Both the compressible Reynolds equation and Darcy's law are linearized and solved iteratively by a successive-over-relaxation method for modeling parallel-surface porous bearings. Three factors affecting the computational efficiency of the numerical model are highlighted and discussed. The hybrid optimization is performed by adopting genetic algorithm (GA) for initial search and accelerated by simplex method (SM) for refined solution. A simple and useful variable transformation is presented and used to convert the unconstrained SM to a constrained method. In this study, the hybrid search algorithm for a multi-variable design exhibits better efficiency compared with the search efficiency by using the SM. The proposed hybrid method also eliminates the need of several trials with random initial guesses to ensure high probability of global optimization. This study presents a new approach for optimizing the performance of porous air bearings and other tribological components. 相似文献
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密封条结构参数优化设计方法 总被引:4,自引:0,他引:4
为了对轿车车门密封条结构参数进行优化设计,采用遗传算法和神经网络相结合的策略,首先利用神经网络建立密封条结构设计参数与压缩负荷、应力等的非线性全局映射关系,获得求解结构优化问题所需的目标函数,然后用遗传算法进行优胜劣汰的寻优搜索运算,求出最优解。优化结果表明,椭圆形结构在壁厚为1.5mm、高度为20mm时,压缩负荷和应力能达到目标函数要求。压缩负荷和应力的优化结果与理论计算值的误差分别为7.4%、9%,因此,利用神经网络和遗传算法进行结构参数优化的方法是可行的。 相似文献
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为使柔性机构在高载荷作用下能实现预期的形状变化,提出了柔性机构的二次优化设计方法。以柔性机构的变形边界与目标边界间的最小平方差(LSE)为优化目标。采用遗传算法(GA),对柔性机构进行全局优化,求得其初始拓扑解;再采用约束随机探索法进行二次优化,求得柔性机构尺寸的精确解。以柔性机构实现机翼前缘形状变化问题为例,运用MATLAB7.1进行编程计算。结果表明,通过对GA初始拓扑解的二次优化,最小平方差下降了31.48%。最后运用ANSYS验证其变形结果基本一致。 相似文献
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Chorng-Jyh Tzeng Yung-Kuang Yang Yu-Hsin Lin Chih-Hung Tsai 《The International Journal of Advanced Manufacturing Technology》2012,63(5-8):691-704
This study analyzed variations of mechanical characteristics that depend on the injection molding techniques during the blending of short glass fiber and polytetrafluoroethylene reinforced polycarbonate composites. A hybrid method including back-propagation neural network (BPNN), genetic algorithm (GA), and response surface methodology (RSM) are proposed to determine an optimal parameter setting of the injection molding process. The specimens are prepared under different injection molding processing conditions based on a Taguchi orthogonal array table. The results of 18 experimental runs were utilized to train the BPNN predicting ultimate strength, flexural strength, and impact resistance. Simultaneously, the RSM and GA approaches were individually applied to search for an optimal setting. In addition, the analysis of variance was implemented to identify significant factors for the injection molding process parameters and the result of BPNN integrating GA was also compared with RSM approach. The results show that the RSM and BPNN/GA methods are both effective tools for the optimization of injection molding process parameters. 相似文献
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基于信息熵理论中的含模糊参数的响应面法 总被引:20,自引:9,他引:20
利用信息熵理论中的概率熵与模糊熵之间的关系式,建立两类不同性质变量之间的转换关系,然后利用这种关系建立一种新型的含有模糊随机变量的响应面法,或根据不确定的信息量,用最大熵法直接建立近似的概率密度函数表达式,算例显示本文方法的可行性和有效性,最后指出,如果结合并行算法,可以从根本上解决响应面法计算效率不高的缺点,使响应面法可用于大型结构的可靠性分析。 相似文献
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大型产品结构优化问题的病毒进化遗传算法 总被引:9,自引:2,他引:9
针对一种大型产品结构的质量-成本优化问题,设计了一种病毒进化遗传算法,提出了相应的编码解码方案和适应度的计算。病毒进化遗传算法是一种协同进化算法,既实现了遗传操作在父子代群体间纵向继承进化信息进行全局搜索的功能,也实现了病毒感染操作在同一代群体中横向传播进化信息进行局部搜索的功能,从而可以比遗传算法较快获得问题的满意解。最后给出了病毒进化遗传算法的试验仿真结果。 相似文献
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Ahn Young Kong Kim Young-Chan Yang Bo-Suk 《Journal of Mechanical Science and Technology》2003,17(12):1938-1948
This paper represents that an enhanced genetic algorithm (EGA) is applied to optimal design of a squeeze film damper (SFD)
to minimize the maximum transmitted load between the bearing and foundation in the operational speed range. A general genetic
algorithm (GA) is well known as a useful global optimization technique for complex and nonlinear optimization problems. The
EGA consists of the GA to optimize multi-modal functions and the simplex method to search intensively the candidate solutions
by the GA for optimal solutions. The performance of the EGA with a benchmark function is compared to them by the IGA (Immune-Genetic
Algorithm) and SQP (Sequential Quadratic Programming). The radius, length and radial clearance of the SFD are defined as the
design parameters. The objective function is the minimization of a maximum transmitted load of a flexible rotor system with
the nonlinear SFDs in the operating speed range. The effectiveness of the EGA for the optimal design of the SFD is discussed
from a numerical example. 相似文献
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准确的立体视觉模型是机器人高精密视觉定位的基础,而传统的单一非线性优化算法难以实现稳定和高精度的机器人立体视觉标定。结合遗传算法全局搜索能力强和粒子群算法局部搜索能力强的特点,提出了一种基于混合群智能优化的机器人立体视觉三步标定方法。针对非线性视觉模型,标定第一步和第二步分别对两个摄像机模型单独作线性初值求解和初次非线性优化,第三步对双目立体视觉模型作联合非线性优化,直接线性变换、遗传算法、粒子群算法分别作用于标定的三个步骤,每一步计算的结果被用作下一步的初始化。仿真试验分析与实际试验结果表明,相对于传统的优化标定方法和使用单一群智能优化算法的标定方法,该方法在噪声环境下具有更高的准确性和鲁棒性,能够更好满足机器人精密视觉操作的需求。 相似文献
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针对标准BP神经网络用于故障诊断时学习效率低、收敛速度慢、易陷入局部极小点及对初始参数较为敏感等不足,提出了一种组合优化的方法,即采用遗传算法(GA)确定BP神经网络的最佳初始权值矩阵,以规避BP神经网络对初始参数较为敏感的不足;应用LM(Levenberg-Marquardt)算法在局部解空间里对BP神经网络进行精确训练,搜索全局最优解。该方法在保留BP神经网络的广泛映射能力的前提下,提升了网络的学习速度和精确搜索能力,进而大幅提高了基于BP神经网络的电液伺服阀故障诊断的效率和精度。通过对MOOG D761-2716A机械反馈伺服阀进行故障诊断,进一步说明了该方法的实用性和高效性。 相似文献
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