共查询到17条相似文献,搜索用时 62 毫秒
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虚拟现实,作为一门新型技术,已成功地应用于工程、设计和制造业领域。本文提出并实现一种基于虚拟现实技术(VR)的塑料注射成型的可视化交互式仿真系统。创新的采用Delaunay三角剖分技术进行成型设备的三维建模,同时提出了模拟注射成型过程运动仿真的方法,结合基于三维模型的注射成型FEA技术,创建注射成型仿真系统。整个系统可在塑料新产品设计的早期阶段及时的发现产品设计和工艺过程中可能出现的错误和缺陷,进行产品设计和生产工艺的优化,保证产品质量,节省开发新产品的时间和费用。 相似文献
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二维电磁态势是战场电磁态势研究的重要内容,是战场电磁频谱管控的重要依据.提出了一种改进的前沿边推进算法来构建Delaunay三角网,提高了Delaunay三角网的构网速度.通过等值点的插值、追踪、平滑处理和等值区的构造,实现了二维电磁态势的可视化.仿真结果表明,采用该方法绘制的二维电磁态势图速度较快. 相似文献
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在地形表达上不规则三角网应用广泛,实际中用到最多的也是Delaunay三角网剖分算法。针对约束数据域下的Delaunay三角剖分通常不满足DT特性的问题进行了阐述,分析了已有的三种引入附加点的算法,算法主要从几何的角度考虑如何减少附加点的数量,而加入附加点的最终目的在于获得更加真实的地形,因而提出了基于边界特征点提取的约束Delaunay三角剖分算法,算法实质就是在加入特征约束之前提取能够满足可以真实再现地形的所有特征点作为新的特征约束,省去附加点的概念,应用现有的Delaunay三角剖分算法进行构网,保证构建后的地形仍具真实感。 相似文献
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初始值优化的离散灰色预测模型 总被引:2,自引:1,他引:1
针对经典GM(1,1)模型的不足,研究了离散GM(1,1)模型选取不同初始迭代点的模拟数据增长率特点.应用最优化技术求解初始迭代点,证明了改进的离散GM(1,1)模型能够完全模拟指数序列.提出了两类分段修正离散GM(1,1)模型,对建模机理进行了证明,并对改进模型进行了推广.结果表明,优化初始迭代点的分段修正离散GM(1,1)模型能够完全拟合分段等比序列. 相似文献
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首先给出了武器装备研制费用和效能的期望值模型。通过Delphifa法确定期望值。提出了费用参数矩阵的概念,根据研制武器系统效能等设计值与期望值绝对差最小原则,建立了基于离散粒子群的费用参数优化模型,并进行了仿真实现。结果表明该方法可行,为武器装备研制的性能参数设计和费用优化提供了一种新方法。 相似文献
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基于离散指数函数优化的GM(1,1)模型 总被引:12,自引:3,他引:12
证明了离散的齐次指数函数经一次累加生成后为离散的非齐次指数函数, 离散的非齐次指数函数经一次累减生成后为离散的齐次指数函数.结合GM(1,1)模型误差产生的原因分析,用非齐次指数函数来拟合一次累加生成序列,推导出最优的背景值计算式.大量的数据模拟和模型比较表明,优化后的模型提高了背景值的精确性以及灰预测模型的拟合精度和预测精度,并且在发展系数绝对值较大时仍然有很高的精度,突破了小于2的限制. 相似文献
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This paper aims to study a novel expansion discrete grey forecasting model, which could aggregate input information more effectively. In general, existing multi-factor grey forecasting models, such as one order and h variables grey forecasting model (GM (1, h)), always aggregate the main system variable and independent variables in a linear form rather than a nonlinear form, while a nonlinear form could be used in more cases than the linear form. And the nonlinear form could aggregate collinear independent factors, which widely lie in many multi-factor forecasting problems. To overcome this problem, a new approach, named as the Solow residual method, is proposed to aggregate independent factors. And a new expansion model, feedback multi-factor discrete grey forecasting model based on the Solow residual method (abbreviated as FDGM (1, h)), is proposed accordingly. Then the feedback control equation and the parameters' solution of the FDGM (1, h) model are given. Finally, a real application is used to test the modelling accuracy of the FDGM (1, h) model. Results show that the FDGM (1, h) model is much better than the nonhomogeneous discrete grey forecasting model (NDGM) and the GM (1, h) model. 相似文献
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一种基于离散粒子群的自适应径向基网络模型 总被引:1,自引:0,他引:1
提出了一种基于离散粒子群的自适应RBF网络模型。即融合两个二进制编码粒子群,通过对最近邻聚类中心选择法的改进,RBF网络模型能自适应地优化隐节点数、中心向量与宽度,且在保证网络性能的前提下,使网络的结构相对简单(较少的隐层节点数)。同时为进一步提高网络性能,采用梯度下降法与递推最小二乘法混合学习策略,分别对基函数参数(中心与宽度)和输出层线性权值进行学习。仿真实验证明了该方法模型的有效性。 相似文献
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对于线性离散系统,给出了一种基于离散二维模型的保性能重复控制设计方法。首先为了提高系统的稳定性引入了状态反馈;用离散二维系统的状态反馈来描述重复控制律;然后,使用保性能重复控制设计方法来确保控制系统性能指标不超过某个性能上界。和现有方法的区别是,通过调节性能指标值泛函中相关权重,能够方便地对控制和学习行为进行独立调节。最后通过仿真验证了该方法能取得满意的跟踪性能。 相似文献
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Cooperative jamming weapon-target assignment (CJWTA) problem is a key issue in electronic countermeasures (ECM). Some symbols which relevant to the CJWTA are defined firstly. Then, a formulation of jamming fitness is presented. Final y, a model of the CJWTA problem is constructed. In order to solve the CJWTA problem efficiently, a self-adaptive learning based discrete differential evolution (SLDDE) algorithm is proposed by introduc-ing a self-adaptive learning mechanism into the traditional discrete differential evolution algorithm. The SLDDE algorithm steers four candidate solution generation strategies simultaneously in the framework of the self-adaptive learning mechanism. Computa-tional simulations are conducted on ten test instances of CJWTA problem. The experimental results demonstrate that the proposed SLDDE algorithm not only can generate better results than only one strategy based discrete differential algorithms, but also outper-forms two algorithms which are proposed recently for the weapon-target assignment problems. 相似文献
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Lü Ganyun 《系统工程与电子技术(英文版)》2008,19(1):131-133
The stabilization of discrete nonlinear systems is studied. Based on control Lyapunov functions, a sufficient and necessary condition for a quadratic function to be a control Lyapunov function is given. From this condition, a continuous state feedback law is constructed explicitly. It can globally asymptotically stabilize the equilibrium of the closed-loop system. A simulation example shows the effectiveness of the proposed method. 相似文献
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针对分布式环境下的战场指挥资源部署存在的效率低、速度慢、无法达到预期战略、数据集过大导致计算资源损耗过大等问题,提出了一种分布式环境下多智能体联盟的指挥控制资源部署优化算法。通过对深度学习中的梯度下降算法进行学习率的改进,将原本设定的学习率改为自适应的学习率,进而对指挥控制资源部署进行多智能体联盟的设计。仿真证明了该算法对此问题具有优越的适应性,可以高效地解决分布式环境下的多智能体联盟的指挥控制资源部署优化问题。 相似文献
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A scheme based on time-varying switching surface for second-order discrete system is introduced. The switching surface is initially designed to pass arbitrary initial conditions, and subsequently move towards a predetermined switching surface by rotating or shifting. This robustness is obtained through shortening the reaching phase. The result of simulation is ensured. 相似文献