仿人机器人手臂抓取运动规划广义逆RRT算法

针对高维空间冗余仿人机器人手臂抓取对象运动规划时所面临的目标位形未知、抓取空间受限、位形空间存在大量障碍物等难题,提出了一种广义逆快速探索随机树法(RRT)避碰运动方法.首先,提出分层子维空间运动规划概念模型,建立了仿人机器人上肢手臂运动学和逆运动学模型;其次,提出一种加权最小范数广义逆RRT规划算法;最后,通过计算机三维仿真,采用基于有向包围盒法开发的碰撞检测算法,验证了该算法的有效性.     

基于多参数优化的多机器人图案构成的分配算法

在不同应用场景下多机器人系统的图案构成受到越来越多的关注,然而现有方法不能有效地优化在障碍物环境中的图案在线自主构成.为解决这一问题,提出一种新的基于目标匹配和路径优化的实时在线的优化算法.首先,以机器人与虚拟期望图案的距离为目标函数,建立一个多参数的图案构成模型,进而在一定的约束条件下求解得到最优的期望图案参数;其次,建立迭代控制器,使机器人在向目标点移动的过程中,可以实时在线地进行机器人与目标点的分配;然后,采用最佳避碰速度算法使机器人无碰撞地到达期望图案的目标点,完成图案构成;最后,通过在MATLAB和V-REP中的仿真实验,验证所提出方法的正确性和有效性.     

基于多目标梯度优化算法PE HMGE的动力总成悬置解耦优化

针对现有车型的动力总成悬置系统解耦率不能满足设计要求的问题,在Adams/View中建立悬置系统的多体动力学模型,通过Isight与Adams的集成,采用树优公司和eArtius公司联合开发的新一代多目标优化算法库PE(ParetoExplorer)中的HMGE(Hybrid Multi-gradient Exploration)算法,解决悬置系统的多目标优化问题.以汽车动力总成悬置系统六自由度解耦率最高作为设计目标,以悬置的各向刚度作为设计变量,同时考虑到各阶模态频率的合理配置分布,兼顾得到理想的频率间隔,成功解决悬置系统的多目标优化问题,并得到更高的优化效率.     

基于弱关联的自适应高维多目标进化算法

对现有的分解方法进行改进,提出一种基于弱关联的自适应高维多目标进化算法(WAEA).首先,提出一种基于夹角子空间的关联策略,使得一个解能与多个参考向量相关联;其次,提出弱关联概念,并基于此概念设计双模态标量函数,使算法能够更好地处理复杂PF问题,此外,算法通过检测参考向量子空间内解的数量,自适应调整惩罚参数大小,使其能...     

基于进化算法的优化平台设计

线性规划非线性规划等优化软件在社会、经济、工程等领域应用潜力巨大。现有优化软件大都采用的是经典的局部优化技术或者简单的全局优化技术。论文将进化算法引入称为优化平台的优化软件设计。对平台的关键技术进行了分析,提出了相应的平台方案,并予以了实现。该平台方案的特点是:界面动态调整增广目标函数中的惩罚因子,使用两个特别的进化算子,采用了特别的并行计算机制和退回机制。经测试,按所提方案实现的平台,操作方便,求解精度高而稳定,有显著的优越性。所提的优化平台方案是令人满意的。     

基于进化蚁群算法的移动机器人路径优化

针对蚁群算法进行路径规划中出现的运行时间长、搜索效率低和容易出现死锁的问题,提出一种基于达尔文进化论思想的蚁群算法.首先,针对空白栅格搜索效率低的问题,提出一种蚁群算法简易模式;然后在启发函数中引入目标影响因子和障碍物影响因子以提高算法的全局搜索能力,避免陷入死锁;最后利用达尔文的进化论改进蚁群算法的信息素更新规则用于加快算法的迭代速度,缩小运行时间.在不同规模的栅格地图环境下的实验表明,所提出的进化蚁群算法能够加快迭代速度,提高搜索效率,实现最优路径并避免算法死锁问题.     

Multimodal optimization using a bi-objective evolutionary algorithm

In a multimodal optimization task, the main purpose is to find multiple optimal solutions (global and local), so that the user can have better knowledge about different optimal solutions in the search space and as and when needed, the current solution may be switched to another suitable optimum solution. To this end, evolutionary optimization algorithms (EA) stand as viable methodologies mainly due to their ability to find and capture multiple solutions within a population in a single simulation run. With the preselection method suggested in 1970, there has been a steady suggestion of new algorithms. Most of these methodologies employed a niching scheme in an existing single-objective evolutionary algorithm framework so that similar solutions in a population are deemphasized in order to focus and maintain multiple distant yet near-optimal solutions. In this paper, we use a completely different strategy in which the single-objective multimodal optimization problem is converted into a suitable bi-objective optimization problem so that all optimal solutions become members of the resulting weak Pareto-optimal set. With the modified definitions of domination and different formulations of an artificially created additional objective function, we present successful results on problems with as large as 500 optima. Most past multimodal EA studies considered problems having only a few variables. In this paper, we have solved up to 16-variable test problems having as many as 48 optimal solutions and for the first time suggested multimodal constrained test problems which are scalable in terms of number of optima, constraints, and variables. The concept of using bi-objective optimization for solving single-objective multimodal optimization problems seems novel and interesting, and more importantly opens up further avenues for research and application.     

基于Pareto的快速多目标克隆选择算法

基于免疫系统中克隆选择原理,提出了一种多目标克隆选择算法MCSA。该方法只对部分当前所得到的Pareto最优解进行进化操作,所求得的Pareto最优解保留在一个不断更新的外部记忆库中,并选用一种简单的多样性保存机制来保证其具有良好的分布特征。实验结果表明,该方法能够很快地收敛到Pareto最优前沿面,同时较好地保持解的多样性和分布的均匀性。对于公认的多目标benchmark问题,MCSA在解集分布的均匀性、多样性与解的精确性及算法收敛速度等方面均优于SPEA、NSGA-II等算法。     

Evolutionary multi criteria design optimization of robot grippers

This paper explores the use of intelligent techniques to obtain optimum geometrical dimensions of a robot gripper. The optimization problem considered is a non-linear, complex, multi-constraint and multicriterion one. Three robot gripper configurations are optimized. The aim is to find Pareto optimal front for a problem that has five objective functions, nine constraints and seven variables. The problem is divided into three cases. Case 1 has first two objective functions, the case 2 considers last three objective functions and case 3 deals all the five objective functions. Intelligent optimization algorithms namely Multi-objective Genetic Algorithm (MOGA), Elitist Non-dominated Sorting Genetic Algorithm (NSGA-II) and Multi-objective Differential Evolution (MODE) are proposed to solve the problem. Normalized weighting objective functions method is used to select the best optimal solution from Pareto optimal front. Two multi-objective performance measures (solution spread measure (SSM) and ratio of non-dominated individuals (RNIs)) are used to evaluate the strength of the Pareto optimal fronts. Two more multi-objective performance measures namely optimizer overhead (OO) and algorithm effort are used to find the computational effort of MOGA, NSGA-II and MODE algorithms. The Pareto optimal fronts and results obtained from various techniques are compared and analyzed.     

一种求解Shubert函数优化问题的演化算法

综合国内外演化计算研究现状,基于热力学中的自由能极小化原理, 设计了一个全新的热力学演化算法,并通过对于Shubert函数优化问题求解的数值试验,测试了热力学演化算法的优良性能,实验结果表明了热力学演化算法求出的解比一般演化算法求出的解更加接近于全局最优。     

A multi objective optimization approach for flexible job shop scheduling problem under random machine breakdown by evolutionary algorithms

This paper addresses the stable scheduling of multi-objective problem in flexible job shop scheduling with random machine breakdown. Recently, numerous studies are conducted about robust scheduling; however, implementing a scheme which prevents a tremendous change between scheduling and after machine breakdown (preschedule and realized schedule, respectively) can be critical for utilizing available resources. The stability of the schedule can be detected by a slight deviation of start and completion time of each job between preschedule and realized schedule under the uncertain conditions. In this paper, two evolutionary algorithms, NSGA-II and NRGA, are applied to combine the improvement of makespan and stability simultaneously. A simulation approach is used to evaluate the state and condition of the machine breakdowns. After the introduction of the evaluation criteria, the proposed algorithms are tested on a variety of benchmark problems. Finally, through performing statistical tests, the algorithm with higher performance in each criterion is identified.     

多主体目标优化的动态合作博弈方法

通过多目标优化和动态合作博弈理论,定义了联盟中多主体目标优化问题,提出了能够适应动态环境的基于合作博弈的多主体目标优化模型。该模型的组成一方面能够利用主体的协作能力,另一方面又能够充分考虑动态联盟的特征,适合大规模网络中多主体协作,避免模型中主体理性和团体理性的冲突。基于所提出的多主体目标优化模型,设计了一种联盟效用分配算法。仿真实验表明,联盟效用分配算法能够使多主体根据最优共识原则,分配各方的合作效用,从而达到多赢的帕累托最优局面。     

多目标遗传算法求解认知无线电性能优化问题

认知无线电的性能优化是一个动态多目标优化问题。现有的Bio-CR模型基于遗传算法优化认知无线电的性能,它使用线性加权方法将此多目标优化问题简化为了一个单目标优化问题。针对Bio-CR很难确定每个适应度函数的权值和容易漏掉一些最优解的问题,提出了基于多目标遗传算法的认知无线电性能优化算法CREA。CREA能够根据信道条件和用户服务需求的变化动态地调整传输参数以优化性能,不仅克服了Bio-CR的两个缺点,而且通过保存计算结果进一步减少了遗传算法的运行次数。CREA首先根据信道条件的变化动态确定一组适应度函数,然后运行多目标遗传算法获得一个Pareto-optimal set,最后根据用户服务需求从中选出一个最满意解,并通知认知无线电更新自己的传输参数。Matlab仿真实验证明了CREA的正确性和有效性。     

Application of evolutionary algorithm in performance optimization of embedded network firewall

With the development of the network, the problem of network security is becoming increasingly serious. The importance of a firewall as the "first portal" to network security is obvious. In order to cope with a complex network environment, the firewall must formulate a large number of targeted rules to help it implement network security policies. Based on the characteristics of the cloud environment, this paper makes in-depth research on network security protection technology, and studies the network firewall system. The system implements unified configuration of firewall policy rules on the cloud management end and delivers them to the physical server where the virtual machine is located. Aiming at the characteristics of virtual machines sharing network resources through kernel bridges, a network threat model for virtual machines in a cloud environment is proposed. Through analysis of network security threats, a packet filtering firewall scheme based on kernel bridges is determined. Various conflict relationships between rules are defined, and a conflict detection algorithm is designed. Based on this, a rule order adjustment algorithm that does not destroy the original semantics of the rule table is proposed. Starting from the matching probability of the rules, simple rules are separated from the default rules according to the firewall logs, the relationships between these rules and the original rules are analyzed, and the rules are merged into new rules to evaluate the impact of these rules on the performance of the firewall. New rules are added to the firewall rule base to achieve linear firewall optimization. It can be seen from the experimental results that the optimization strategy proposed in this paper can effectively reduce the average number of matching rules and improve the performance of the firewall.     

PBIL进化算法求解排污口布局优化问题的研究

排污口的布局对水生态系统的良性发展和城市环境美化起着至关重要的作用。利用基于概率分析策略的PBIL算法,综合考虑影响排污口布局的区域地理条件、水环境容量、水域纳污能力、水生态资源等约束条件,并利用层次分析法确定影响因子的权重值。利用罚函数法构造了排污口优化设置问题的模型,设计了整数编码方式,并应用于工程实例。结果表明了该算法能较为准确合理地求解此类问题,为经济的可持续发展提供了较好的技术支持。     

Bell-curve based evolutionary optimization algorithm

The paper presents an optimization algorithm that falls in the category of genetic, or evolutionary algorithms. While the bit exchange is the basis of most of the Genetic Algorithms (GA) in research and applications in America, some alternatives, also in the category of evolutionary algorithms, but using a direct, geometrical approach have gained popularity in Europe and Asia. The Bell-Curve Based Evolutionary Algorithm (BCB) is in this alternative category and is distinguished by the use of a combination ofn-dimensional geometry and the normal distribution, the bell-curve, in the generation of the offspring. The tool for creating a child is a geometrical construct comprising a line connecting two parents and a weighted point on that line. The point that defines the child deviates from the weighted point in two directions: parallel and orthogonal to the connecting line, the deviation in each direction obeying a probabilistic distribution. Tests showed satisfactory performance of BCB. The principal advantage of BCB is its controllability via the normal distribution parameters and the geometrical construct variables.College of William and Mary     

Evolutionary multi objective optimization for rule mining: a review

Evolutionary multi objective optimization (EMOO) systems are evolutionary systems which are used for optimizing various measures of the evolving system. Rule mining has gained attention in the knowledge discovery literature. The problem of discovering rules with specific properties is treated as a multi objective optimization problem. The objectives to be optimized being the metrics like accuracy, comprehensibility, surprisingness, novelty to name a few. There are a variety of EMOO algorithms in the literature. The performance of these EMOO algorithms is influenced by various characteristics including evolutionary technique used, chromosome representation, parameters like population size, number of generations, crossover rate, mutation rate, stopping criteria, Reproduction operators used, objectives taken for optimization, the fitness function used, optimization strategy, the type of data, number of class attributes and the area of application. This study reviews EMOO systems taking the above criteria into consideration. There are other hybridization strategies like use of intelligent agents, fuzzification, meta data and meta heuristics, parallelization, interactiveness with the user, visualization, etc., which further enhance the performance and usability of the system. Genetic Algorithms (GAs) and Genetic Programming (GPs) are two widely used evolutionary strategies for rule knowledge discovery in Data mining. Thus the proposed study aims at studying the various characteristics of the EMOO systems taking into consideration the two evolutionary strategies of Genetic Algorithm and Genetic programming.     

Novel integrated optimization algorithm for trajectory planning of robot manipulators based on integrated evolutionary programming

Optimal trajectory plarmmg for robot manipulators plays an important role in implementing the high productivity for robots. The performance indexes used in optimal trajectory planning are classified into two roam categories:optimum traveling time and optimum mechanical energy of the actuators. The current trajectory planning algorithms are designed based on one of the above two performance indexes. So far, there have been few planning algorithms designed to satisfy two performance indexes simultaneously. On the other hand, some deficiencies arise in the existing integrated optimization algorithms of trajectory planning.In order to overcome those deficiencies, the integrated optimization algorithms of trajectory planning are presented based on the complete analysis for trajectory planning of robot manipulators. In the algorithm, two object functiom are designed based on the specific weight coefficient method and “ideal point” strategy. Moreover, based on the features of optimization problem, the intensified evolutionary programming is proposed to solve the corresponding optimization model. Especially, for the Stanford Robot, the high-quality solutions are found at a lower cost.