共查询到20条相似文献,搜索用时 656 毫秒
1.
低速稳定性是伺服系统的一个重要性能指标.低速下,摩擦力的扰动引起伺服控制系统的不稳定.首先建立了伺服系统的动力学模型.模型由线性部分和非线性部分组成,非线性部分主要由摩擦力等扰动组成,使用最小二乘支持向量机对摩擦力等非线性部分、不确定参数进行辨识.其次,建立了基于线性伺服控制系统和摩擦力模型的补偿控制系统,并提出使用改进的优化滑模控制算法,同时对采样时间周期提出了优化选择.仿真结果显示:使用支持向量机建立的摩擦力模型能够较准确地反映系统低速摩擦力情况,对系统的低速补偿效果良好.低速时,误差控制在0.5r/min;通过实验研究,使用了摩擦力补偿和优化滑模控制后伺服系统的低速性能得到了改善和提高,克服了低速爬行现象. 相似文献
2.
在伺服系统优化控制设计问题的研究中,对于伺服转台控制系统,当系统进行低速跟踪时,由于摩擦力矩的存在,会使系统出现低速爬行现象.针对伺服电机运行时产生的摩擦扰动,进行理论分析与研究,提出一种补偿摩擦力矩的控制器,使系统满足高精度要求.在MATLAB仿真平台上,建立滑模自适应控制器的控制系统仿真模型,仿真结果表明滑模自适应控制器不仅对模型参数的随机性具有自适应的能力,而且对摩擦扰动和其他扰动信号具有鲁棒稳定性.采用滑模自适应控制器的伺服系统可以获得较高的跟踪精度的同时具有一定的鲁棒稳定性,且系统抖振较小. 相似文献
3.
伺服控制系统中非线性摩擦力矩的干扰是影响系统性能提高的主要因素。为了减小摩擦力矩的影响,提出了基于扩展卡尔曼滤波器的状态观测器对摩擦力进行估计,采用改进型Tustin摩擦模型仿真实际摩擦力矩。Matlab仿真结果表明,构建的摩擦观测器能较准确地对摩擦力进行估计,加入摩擦力补偿后能有效改善运动控制系统性能,速度误差由18%降低到3%。 相似文献
4.
本文针对系统中存在的关节摩擦、动力学参数不确定性和外部负载干扰等因素引起的柔性机械臂系统控制性能下降的问题,提出了一种基于扰动和摩擦补偿的非奇异快速终端滑模控制方法(NFTSMC-DE-FC).首先,设计扰动估计器(DE)对系统未知动态参数和负载干扰进行估计.然后,针对扰动估计器不能精确估计的关节摩擦力矩进行辨识.最后,利用滑模控制技术设计非奇异快速终端滑模控制器,并将扰动估计值和摩擦力辨识值以前馈的方式进行补偿,实现对柔性机械臂系统给定参考轨迹跟踪的准确性以及对外界扰动的鲁棒性.值得注意的是,与传统只使用扰动估计器的方法相比,本文考虑到了摩擦力等非线性因素的影响,并利用辨识技术对摩擦力进行辨识,提高了控制精度.利用Lyapunov稳定性定理从理论上证明了所设计的控制器可以保证闭环系统的稳定性.实验结果表明,相较于非奇异快速终端滑模控制方法(NFTSMC)和基于扰动估计器的非奇异快速终端滑模控制方法(NFTSMC-DE),所提方法提高了柔性机械臂系统的轨迹跟踪性能. 相似文献
5.
6.
7.
8.
9.
10.
爬行波是非镜面散射问题中的一类重要问题,射线寻迹是求解爬行波散射贡献的关键环节.文中基于短程线的定义,结合自由曲线曲面几何造型技术,探讨了对任意凸曲面导体目标表面进行爬行波射线寻迹的方法.对可展面爬行波射线寻迹计算进行了讨论,计算结果与理论值吻合,证明了方法的有效性;在此基础上,对解析求解困难的非可展面的爬行波射线寻迹进行了计算. 相似文献
11.
张涛 《计算机测量与控制》2015,23(1):86-89
为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值. 相似文献
12.
In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times. 相似文献
13.
《Information & Management》2016,53(6):787-802
Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice. 相似文献
14.
Distributed real-time simulation is a young technology field but its practice is under increasing demands. In recent years the author and his collaborators have been establishing a new approach called the distributed time-triggered simulation (DTS) scheme which is conceptually simple and easy to use but widely applicable. The concept was initiated in the course of developing a new-generation object-oriented real-time programming scheme called the time-triggered message-triggered object (TMO) programming scheme. Some fundamental issues inherent in distributed real-time simulation that were learned during recent experimental studies are discussed along with some approaches for resolving the issues. An execution engine developed to support both the TMOs engaged in control computation and the TMOs engaged in DTS is also discussed along with its possible extensions that will enable significantly larger-scale DTSs. 相似文献
15.
Zusammenfassung Mit zunehmender Größe der Softwaresysteme verschärfen sich die für die Software-Herstellung typischen Probleme: Beherrschen großer Objektmengen, Erhalten der Systemkonsistenz, Kontrolle der ständigen Änderungseinflüsse und Gewährleisten einer langen Lebensdauer. Die Disziplin Konfigurationsmanagement bildet den methodischen Ansatz, diese Probleme besser zu beherrschen. Software-Konfigurationsmanagement faßt die Herstellung von Softwaresystemen als eine Abfolge von kontrollierten Änderungen an gesicherten Zwischen- und Endergebnissen auf. Dargestellt werden die Objekte und Funktionen des Software-Konfigurationsmanagements sowie die hierfür in großen Software-Projekten benötigten Methoden, Instanzen und Hilfsmittel. 相似文献
16.
《浙江大学学报:C卷英文版》2014,(11)
正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and 相似文献
17.
Zhao-hui WU 《浙江大学学报:C卷英文版》2014,(10)
正Brain-machine interfaces(BMIs)aim at building a direct communication pathway between the brain and an external device,and represent an area of research where significant progress has been made during the past decade.Based on BMIs,mind information can be read out by neural signals to control 相似文献
18.
《浙江大学学报:C卷英文版》2014,(10)
正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate 相似文献
19.
20.
《浙江大学学报:C卷英文版》2014,(8)
正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate 相似文献