共查询到20条相似文献,搜索用时 187 毫秒
1.
2.
3.
《数学的实践与认识》2017,(19)
针对多产品定制环境中的可实现性约束冲突问题和用户满意度最大化问题,基于Kano模型建立了多产品在线定制的原始模型;并通过逆优化模型来合理调整其中的产品配置参数和可实现性约束参数,对用户现有的个性化产品配置方案进行优化.算例表明,方法能够保证给定产品需求成为最优解,为有效引导用户在线定制活动提供新思路. 相似文献
4.
《数学的实践与认识》2020,(15)
工业机器人应该在尽可能短的周期内完成复杂的任务,以获得高生产率.确定机械手末端执行器访问多个任务点的最佳路径的问题与著名的旅行商问题(TSP)相似,但并不完全相同.为了使TSP适应机器人技术,需要优化的度量是时间而不是距离.另外,任意两点之间的行程时间受机械手构型的选择影响较大.因此,需要考虑运动学逆问题的多重解.逆运动学问题的求解是机器人控制的基础.许多传统的逆运动学问题的解决方法,如几何、迭代和代数方法,对冗余机器人来说是不够的.以此为出发点,基于遗传算法提出了一种新的编码方法来考虑逆运动学问题的多重解,方法适用于任何非冗余度的机械手.仿真实验结果显示,提出的方法能在一定的时间内快速找到最优解或近似最优解.且任何非冗余度机械手的多重配置很容易体现在遗传算法的编码中. 相似文献
5.
6.
主要研究了单/多列车运行优化控制问题.首先建立了面向节能的单列车能耗优化模型,采用节能控制策略对模型进行求解,得出节能运行的速度距离曲线;其次对多列车多区段的节能运行进行优化控制设计,以再生能量利用最大化为目标,分别建立多列车能耗优化通用模型和高峰/非高峰情形下优化模型,利用模拟退火算法求解模型,得出使总能耗最低的列车运行方案;最后针对晚点情况下追踪运行的多列车运行优化控制问题,分别建立随机和非随机晚点情况下实时控制模型,求解得到耗能最少的列车运行曲线. 相似文献
7.
证券组合投资决策的β模型 总被引:8,自引:0,他引:8
本文基于证券组合系统风险和非系统风险的定量分析,建立了含β约束的证券组合多目标优化模型。文中给出了模型的解析解,分析了解的性态,并通过数值例子检验了模型的解,研究结果表明,只要适当控制证券组合的非系统风险,就能确保所求证券组合具有良好的分散性,从而较好地解决了β-类模型中的投资分散问题。 相似文献
8.
《数学的实践与认识》2016,(1)
针对建设项目的复杂性和动态性,建立基于改进微粒群算法的多目标动态优化模型.首先,为提高算法性能,引入外部归档集和阈值并构建基于理想点法的适应度函数;其次,分别建立工期模型、加入系统可靠度的质量模型以及加入费用现值的成本模型,由其得到综合优化模型;最后结合工程实例对算法进行验证并与非劣分类遗传算法(NSGA-Ⅱ算法)对比.结果表明:方法比NSGA-Ⅱ算法的优化结果更科学、收敛速度更快. 相似文献
9.
10.
对小麦发育后期茎秆抗倒伏性进行了研究.建立了基于茎秆密度和机械强度的改进型抗倒伏指数模型;采用相关系数、通径分析、灰色关联分析三种方法对倒伏指数与外部形态的关联性进行了分析;提出了理想株型结构的定义,建立双目标优化模型探讨理想模型的数值解;分别从茎秆线密度线性变化、分节几何性质均匀以及分节物理性质均匀的情况下获得三个抗倒伏模型;最后为小麦茎秆抗倒伏研究提出了建议. 相似文献
11.
Kinematics of an offset 3-UPU translational parallel manipulator by the homotopy continuation method
S.M. Varedi H.M. Daniali D.D. Ganji 《Nonlinear Analysis: Real World Applications》2009,10(3):1767-1774
For most parallel manipulators, the inverse kinematics is straightforward, while the direct kinematics is challenging. The latter requires the solution of a system of nonlinear equations. In this paper we use the homotopy continuation method to solve the forward and inverse kinematic problems of an offset 3-UPU translational parallel manipulator. The homotopy continuation method is a novel method which alleviates drawbacks of the traditional numerical techniques, namely; the acquirement of good initial guess values, the problem of convergence and computing time. The direct kinematics problem of the manipulator leads to 16 real solutions. 相似文献
12.
《Applied Mathematical Modelling》2014,38(7-8):1983-1999
In this paper, the inverse kinematics solutions for 16 industrial 6-Degrees-of-Freedom (DOF) robot manipulators with offset wrists are solved analytically and numerically based on the existence of the closed form equations. A new numerical algorithm is proposed for the inverse kinematics of the robot manipulators that cannot be solved in closed form. In order to illustrate the performance of the New Inverse Kinematics Algorithm (NIKA), the simulation results attained from NIKA are compared with those obtained from well-known Newton–Raphson Algorithm (NRA). The inverse kinematics solutions of two robot manipulators with offset wrists are given as examples. In order to have a complete idea, the inverse kinematics solution techniques for 16 industrial robot manipulators are also summarized in a table. 相似文献
13.
人体逆向运动学问题是人体运动合成、人体运动捕获和理解的基本问题.由于人体关节链式系统的复杂性,人体逆向运动学方程往往存在多解或无解的情形.传统的方法通常采用解析或数值迭代方法求解逆向运动学问题,在给定足够多约束的情形下能够得到比较好的解,但无法处理少量约束下生成自然的人体姿态问题.近年来,从大规模数据集中学习统计模型参数的思想被广泛运用,求解人体逆向运动学的机器学习方法中经典工作|混合Gauss逆向运动求解模型(Gaussian mixture model-inverse kinematics,GMM-IK)就提出利用混合Gauss模型建模人体姿态数据分布,并采用期望最大化方法求解参数.随着深度学习技术的发展,本文提出一种自编码神经网络与数值迭代融合的方法,在给定少量约束的情形下依然能够得到自然的人体姿态,相较于GMM-IK方法,本文所提出的方法通过神经网络自动学习姿态分布,省去了模型的假设和特征的设计,且量化实验显示本文方法的关节坐标和角度重建误差相较于GMM-IK模型平均减少了25%和39%.在应用方面,本文方法可处理光学运动捕获数据,也可用于图像视频的人体姿态估计等领域. 相似文献
14.
David J. Murray-Smith 《Mathematical and Computer Modelling of Dynamical Systems: Methods, Tools and Applications in Engineering and Related Sciences》2013,19(5):515-541
Inverse simulation is a form of inverse modelling in which computer simulation methods are used to find the time histories of input variables that, for a given model, match a set of required output responses. Conventional inverse simulation methods for dynamic models are computationally intensive and can present difficulties for high-speed applications. This article includes a review of established methods of inverse simulation, giving some emphasis on iterative techniques that were first developed for aeronautical applications. It goes on to discuss the application of a different approach that is based on feedback principles. This feedback method is suitable for a wide range of linear and non-linear dynamic models and involves two distinct stages. The first stage involves design of a feedback loop around the given simulation model, and in the second stage, that closed-loop system is used for inversion of the model. Issues of robustness within closed-loop systems used in inverse simulation are not significant as there are no plant uncertainties or external disturbances. Thus, the process is simpler than that required for the development of a control system of equivalent complexity. Engineering applications of this feedback approach to inverse simulation are described through case studies that put particular emphasis on non-linear and multi-input multi-output models. 相似文献
15.
16.
V. G. Romanov 《Siberian Mathematical Journal》2012,53(6):1128-1138
For the integrodifferential equation that corresponds to the two-dimensional viscoelasticity problem, we study the problem of determining the density, the elasticity coefficient, and the spaceintegral term in the equation. We assume that the sought functions differ from the given constants only inside the unit disk D = {x ∈ ?2 | |x| < 1}. As information for solving this inverse problem, we consider the one-parameter family of solutions to the integrodifferential equation corresponding to impulse sources localized on straight lines and, on the boundary of D, there are defined the traces of the solutions for some finite time interval. It is shown that the use of a comparatively small part of the given information about the kinematics and the elements of dynamics of the propagating waves makes it possible to reduce the problem under consideration to three consecutively and uniquely solvable inverse problems that together give a solution to the initial inverse problem. 相似文献
17.
18.
19.
20.
Gao Tianling Ma Fuming Zhang Deyue 《高校应用数学学报(英文版)》2007,22(3):259-266
The time-harmonic electromagnetic plane waves incident on a perfectly conducting obstacle in a homogeneous chiral environment are considered.A two-dimensional direct scat- tering model is established and the existence and uniqueness of solutions to the problem are discussed by an integral equation approach.The inverse scattering problem to find the shape of scatterer with the given far-field data is formulated.Result on the uniqueness of the inverse problem is proved. 相似文献