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采用减振方式减小运载火箭在发射状态对空间飞行器产生的过载是一种理想形式,但通常减振设计必须进行详细计算与实际验证,周期长,准确性差,费用高.因此,文中提出了一种新的采用减振措施来减小发射段振动的影响的方法;又采用虚拟样机技术,利用ADAMS动力学仿真软件对其横向振动特性进行了仿真研究,表明该方法可以有效的减小发射状态下的过载对空间飞行器的影响;并提出用ADAMS软件建模对该系统进行参数优化设计的具体方法.同时表明,用ADAMS软件建立减振系统三维实体模型进行仿真设计,具有速度快、分析方便、便于实施和结果准确等特点,是理想的一种设计方法. 相似文献
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未来空域窗射击体制是一种新型的高炮射击体制, 这种射击体制对近程防空反导具有显著的效果. 在对未来空域窗进行设计和评价时, 必须计算未来空域窗内弹头散布的均匀度, 并要求算法具有全局收敛以及解的精度高. 文章描述了未来空域窗弹头散布均匀度的问题, 提出了一种求解弹头散布均匀度的分布估计算法; 然后, 提出了一种变焦算法用来提高算法的搜索效率和解的精度, 并给出了混合算法的流程图. 仿真结果表明, 混合算法具有全局收敛、解的精度高以及搜索效率高的优点, 适合于在实际工程中用来求解弹头散布均匀度. 相似文献
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机械四连杆机构是机械类的典型机构,其设计与运动分析具有很强的理论性和实践性。针对作图法和解析法对该类机构进行运动分析的不足,在基于经典机构学理论的基础上,采用ADAMS(Automatic Dynamic Analysis of Mechanical Systems)动力学仿真方法,可实现对铰链四杆机构的运动特性的直观、高效而准确的计算机辅助分析。然后,采用多体系统动力学理论,通过ADAMS分析了机构的简化方法并进行运动学仿真,对四连杆机构中杆件的传动角、位移、速度及运动轨迹进行了分析。 相似文献
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根据传感器网络的特性,结合蚂蚁算法能够快速找出最优路径的特点,提出了一种基于偏转角的蚂蚁路由算法.该算法采用轮盘赌选择方法,加入偏转角、能量以及距离作为启发因子,迅速生成source到sink的优化路由;并针对算法中人工蚂蚁之间有通信和无通信两种状况,分别做了仿真实验和性能分析. 相似文献
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飞行模拟器具有真实飞行训练无法比拟的优势,其结构设计是优化飞机设计,改善飞行性能的关键问题,故飞行模拟器的建模与仿真研究工作是飞行器设计的难点。通过与液压缸驱动的六自由度飞行模拟器对比分析,以3-RPS机构为基础,以在UG环境下建立的电动缸驱动的三自由度飞行模拟器运动平台模型为研究对象,在ADAMS/View模块下,对其添加约束和驱动后,进行了运动学特性仿真。对于给定的运动学特性曲线,运用ADAMS/Post Processor模块,对测量结果进行后处理,得到各种飞行姿态下的运动学曲线。仿真实验结果验证了该设计可实现升降、横滚、俯仰三种姿态的运动,且符合民航飞行模拟器的技术指标要求。上述分析过程为飞行模拟器的设计提供了一套有效的研究方法。 相似文献
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为了对食物品质进行非接触式评价,基于6种费加罗金属氧化物气体传感器阵列,通过由数据采集模块和微处理器模块组成的硬件设计方案,设计并研制了可对被测食物进行实时、无损检测的电子鼻系统。在软件设计方案上,该系统采用主成分分析(PCA)和反向传播(BP)混合神经网络模式,通过LabVIEW对气体"指纹信息"数据库进行分析。实验结果表明:该设计的电子鼻系统可以很好地区分不同种类的食醋,并提供了一种对食醋品质评价的便利方法。 相似文献
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在新涡桨支线飞机机头结构初始方案设计阶段,采用MSC Nastran对机头初始设计方案进行总体结构分析和尺寸优化,为机头结构选型和详细设计提供参考. 相似文献
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针对机构方案概念设计的自动化程度不高的缺陷,提出了功能向量编码方法.该方法将机构功能用功能向量表示,功能向量所包含的对偶功能向量和功能矩阵分别表示功能向量的方向特性和量化特性,同时引入了补偿矩阵以对功能矩阵进行多次分解.建立了机构功能库,开发了机构方案概念设计系统,并将功能向量编码方法应用于机构功能的提取和操作.应用结果表明,将该方法应用于机构方案概念设计是可行的,提高了机构方案概念设计的自动化程度. 相似文献
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Yongchao Man 《International journal of control》2016,89(5):1038-1046
This paper addresses the global adaptive stabilisation via switching and learning strategies for a class of uncertain nonlinear systems. Remarkably, the systems in question simultaneously have unknown control directions, unknown input disturbance and unknown growth rate, which makes the problem in question challenging to solve and essentially different from those in the existing literature. To solve the problem, an adaptive scheme via switching and learning is proposed by skilfully integrating the techniques of backstepping design, adaptive learning and adaptive switching. One key point in the design scheme is the introduction of the learning mechanism, in order to compensate the unknown input disturbance, and the other one is the design of the switching mechanism, through tuning the design parameters online to deal with the unknown control directions, unknown bound and period of input disturbance and unknown growth rate. The designed controller guarantees that all the signals of the resulting closed-loop systems are bounded, and furthermore, the closed-loop system states globally converge to zero. 相似文献
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将双参数四点细分曲线方法进行推广,提出了基于双参数四点细分法的曲面造型方法,并对其收敛性进行了分析。该方法通过对两个参数的适当调节能够较容易地控制极限曲面的形状,极限曲面能够达到C4连续,可以应用到对曲面的连续性要求较高的曲面造型中去。在给定初始数据的条件下,可通过对形状参数的适当选择来实现对极限曲面的形状调整和控制,试验表明该算法生成光滑曲面是有效的。 相似文献
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One of the main issues related to the reliable operation of network control systems concerns the design of mechanisms able to detect anomalies in the functioning of the communication network through which the control loops are closed. In this article, we address the problem of detecting the occurrence of packet losses and design a mechanism that can detect the occurrence of packet losses directly from process sensor data. Specifically, we propose a moving‐horizon estimation scheme that permits to detect if the packet‐loss rate exceeds prescribed thresholds, which are representative of stability and performance of the control system. We discuss theoretical properties of the proposed solution along with an approximation scheme with reduced computational burden. A numerical example is discussed to substantiate the analysis. 相似文献
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current investigation focused on neural-network-based control of manufacturing processes utilizing an optimization scheme. In an earlier study, Demirci and Coulter introduced the utilization of neural networks for the intelligent control of molding processes. In that study, a forward model neural network, employed with a search strategy based on the factorial design of experiments method, was shown to successfully control the flow progression during injection molding processes. Recently, Demirciet al. showed that the search mechanism based on the factorial design of experiments method can be intolerable in time during on-line control of manufacturing processes, and suggested an inverse model neural network. This inverse model neural network was shown to be beneficial as it totally eliminated time-consuming parameter searches, but it required a harder mapping than the forward model neural network and thus its performance was inferior. In the present study, the authors investigated two different optimization methods that were utilized in making the search method of the forward control scheme more efficient. The first method was Taguchi's method of parameter design, and the second method was a nonlinear optimization method known as Nelder and Mead's downhill simplex method. These two methods were separately utilized in creating an efficient search method to be used with the forward model neural network. The performance of the resulting two control methods was compared with each other as well as with that of the forward control scheme utilizing a search strategy based on the factorial design of experiments method. Although the applications in this study were on molding processes, the method can be applied to any manufacturing process for which a process model and anin-situ sensing scheme exists. 相似文献
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氮氧化物一直是评价环境空气质量的重要指标之一,采取严格的质量控制手段是测量结果准确、可靠的重要保证。探讨了柴油车氮氧化物检测仪NO2-NO的转化机理,并介绍了钼炉转换效率的计算方法;通过试验步骤优化设计和测量过程控制,研究了一种可靠的转化率测量方案。试验结果表明,标准气体法是一种相对可靠的转化效率测试方法,NO2标准气体浓度、反应时间等因素均会影响转化率的测量结果。此外,在实际使用过程中,检测仪催化剂钥芯转化效率会随着时间老化衰减,相关监管部门应设计相应的管理机制以确保该类设备检测结果的准确、可靠。 相似文献