A stable friction compensation scheme for motion control systems

In mechanical positioning control systems, friction phenomenon makes undersirable responses. Friction compensation scheme is frequently implemented to the control system together with the friction estimator in order to cancel the effect of the friction. However, the error in the estimation of the friction results in undercompensation or overcompensation, which also makes undesirable responses. In this paper, a new friction compensation scheme is proposed. The stability analysis is performed based on the circle criterion, which provides a sufficient condition for asymptotic stability of a system. For an application example, the scheme is implemented to a mechanical positioning system of a second-order plant with nonlinear friction. The effectiveness of this scheme is illustrated with the time responses obtained by computer simulation.     

Static output feedback stabilization of networked control systems with a parallel-triggered scheme

This paper investigates the parallel-triggered static output feedback stabilization problem for linear networked control systems. A new parallel-triggered scheme is proposed by using both the relative error and the absolute error information. The scheme can reduce transmission rate while maintaining the global asymptotical stability. The linear parallel-triggered networked control system is modeled as a time-delay system. By employing Lyapunov stability theory, sufficient conditions are established for the closed-loop system to be globally asymptotically stable in terms of linear matrix inequalities. Moreover, a co-design algorithm is developed to obtain both the optimal trigger parameters and the output feedback controller gain in the sense that the transmission rate is minimized. Finally, two examples are given to illustrate the advantages of the proposed scheme.     

48V/500A全数字交流调速控制器主电路及保护电路的设计

随着电力电子技术及大规模集成电路的发展,基于集成SPWM电路构成的变频调速系统以其结构简单、运行可靠、节能效果显著等突出优点以及先进的IGBT技术得到广泛应用。本文介绍48 V/500 A全数字交流调速控制器主电路及其保护电路的设计。     

数字存储示波器时基及触发特性的精确评价

本文提出一种数字存储皮器时基和触发特性的精确评价方法,通过使用正弦波拟合法,其时基准确度,触发沿斜率,触发电平不确定度,触发延时误差以及触发沿晃动被精确评价;详细描述了其测量原理,并给出了误差分析和实验例证,验证了该方法及过程的可行性。     

一种新型压电陶瓷微驱动电路的设计

本文介绍了压电陶瓷微位移控制电路的基本原理殛特点，并对直流放大式电路进行了详细的分析和实验研究，指出存在的缺点和不足，在此基础上提出了一种新型的压电陶瓷微位移控制电路。     

一种实用温度测量电路的设计

介绍采用铂热电阻、集成化铂热电阻信号调理器、A/D转换器、LED显示器以及其它器件设计的一种实用温度测量电路。详细阐述电路的组成、工作原理、各部分电路分析、选择参数等。该电路具有测量范围宽、精度高、结构简单、价格低廉等特点。     

Anti-disturbance dynamic surface control scheme for a class of uncertain nonlinear systems with asymmetric dead-zone nonlinearity

This study proposes anti-disturbance dynamic surface control scheme for nonlinear strict-feedback systems subjected simultaneously to unknown asymmetric dead-zone nonlinearity, unmatched external disturbance and uncertain nonlinear dynamics. Radial basis function-neural network (RBF-NN) is invoked to approximate the uncertain dynamics of the system, and the dead-zone nonlinearity is represented as a time-varying system with a bounded disturbance. The nonlinear disturbance observer (NDO) is proposed to estimate the unmatched external disturbance which further will be used to compensate the effect of the disturbance. Then, by integrating RBF-NN, NDO and dynamic surface control (DSC) approaches, the proposed anti-disturbance control scheme is designed. Stability analysis of the closed-loop system shows that all signals of the closed-loop system are semi-globally uniformly ultimately bounded and the tracking error can be made arbitrarily small by proper selection of the design parameters. In comparison with the existing methods, the proposed scheme deals with the unmatched external disturbance, uncertain dynamics and unknown asymmetric dead-zone nonlinearity, simultaneously; it avoids the "explosion of complexity" problem and develops the simple control law without singularity concern. Furthermore, some imposed assumptions to the dead-zone input and disturbances are relaxed. Simulation and comparison results verify the effectiveness of the proposed approach.     

基于泛逻辑推理的复杂产品融合绿色性分析的设计方案评价技术

为了更准确地支持复杂产品的方案评价并综合考虑产品的绿色特性,研究了基于泛逻辑推理的复杂产品融合绿色性分析的方案评价技术.用功能与或树及匹配命题集的形式实现了复杂产品方案的命题表达,并采用各独立匹配命题分别评价再整体集成的方法,细化了评价过程.将产品性能指标分为功能性评价指标和绿色性评价指标,以各独立匹配命题为单位,采用模糊综合评判的方法分别进行评估.利用泛逻辑学中建立的命题自相关性和互相关性对命题真值的影响模型将两者有效结合,同时充分考虑各独立方案之间的集成特性,运用复合命题的泛逻辑推理方法实现整体方案的评价.以自动化焊接中心的方案评价为例,验证了方法的可行性.     

供应商参与下的产品部件设计方案选择模型

研究了供应商参与下新产品部件设计方案的选择问题。通过引进综合表现度的概念来表征部件设计方案对成形产品顾客满意度的贡献。基于模糊综合评判、综合供应商的评价等级及备选方案的表现度,确定各设计方案的综合表现度。基于质量功能配置思想,建立了产品规划和部件规划质量屋。利用质量屋的信息和部件设计方案的综合表现度,建立了供应商参与下部件设计方案选择的组合优化模型。该模型考虑设计制造企业的成本约束,以产品部件组合方案的综合表现度最大为目标。以液晶显示器为实例,说明了模型的应用。     

直接驱动式共轨系统可控针阀升程的驱动电路研究

针对柴油发动机喷油速率的控制问题,对喷油速率的控制方式进行了归纳总结,对直接驱动式共轨系统的特点和优势,以及直驱喷油器针阀的控制方式进行了分析,对于压电执行器的驱动电路以及充放电控制策略进行了分析,将可变电阻这一思路引入到电压反馈电路中,设计出了驱动电路的可变反馈模块,通过电控单元控制反馈电阻的选取,实现了在燃油喷射过程中对压电执行器驱动电压以及针阀升程的阶梯控制。对驱动电路进行了仿真优化设计,并利用压电执行器来对驱动电路进行了试验验证。研究结果表明,压电执行器完全充放电时间在120μs左右,喷油过程中驱动电压的变化可在100μs内实现,满足共轨系统对针阀的响应要求,所设计的驱动电路能够在燃油喷射过程中通过改变驱动电压来控制喷油速率。     

Performance analysis of active disturbance rejection tracking control for a class of uncertain LTI systems

The paper considers the tracking problem for a class of uncertain linear time invariant (LTI) systems with both uncertain parameters and external disturbances. The active disturbance rejection tracking controller is designed and the resulting closed-loop system׳s characteristics are comprehensively studied. In the time-domain, it is proven that the output of closed-loop system can approach its ideal trajectory in the transient process against different kinds of uncertainties by tuning the bandwidth of extended state observer (ESO). In the frequency-domain, different kinds of parameters׳ influences on the phase margin and the crossover frequency of the resulting control system are illuminated. Finally, the effectiveness and robustness of the controller are verified through the actuator position control system with uncertain parameters and load disturbances in the simulations.     

基于Wiener过程的万能式断路器附件剩余寿命预测*

万能式断路器作为一个复杂的机械系统,其操作附件的剩余寿命预测对于维护断路器的可靠性至关重要。为准确掌握操作附件剩余寿命情况,提出了一种基于Wiener过程的万能式断路器操作附件剩余机械寿命预测方法。首先,通过对操作附件动作过程中线圈电流波形的分析选取了动作时间作为性能退化特征量;其次,考虑到断路器操作附件性能退化过程具有线性非单调的特点,采用Wiener过程建立了操作附件的性能退化模型,并利用极大似然估计法对退化模型参数进行估计;然后,基于首达时间的概念建立了剩余寿命预测模型,推导出剩余寿命概率密度函数解析式。最后对安装于万能式断路器上的分励脱扣器和释能电磁铁两种操作附件进行全寿命试验及其剩余寿命预测,预测结果验证了所提方法的有效性。     

基于线圈瞬态电流参数优化的真空断路器永磁操动机构动作特性研究

针对永磁操动机构出力不足、动作特性与真空断路器开断性能难以配合的问题,对单线圈双稳态真空断路器永磁操动机构进行了研究,在剖分永磁操动机构结构的基础上,分析了磁路磁链的分布关系,建立了三维电磁场数学模型。采用有限元法仿真分析方法,求解了永磁操动机构线圈瞬态电流与动铁芯合闸动作特性之间的关系,并探讨永磁操动机构储能电容容量、电源电压、线圈匝数和负载等效质量等主要参数对真空断路器合闸动作特性的影响。研究结果表明,仿真计算数据与试验测试数据吻合,优化后的电容、线圈及负载参数可对永磁操动机构的位移检测、系统故障诊断、结构改进等提供理论依据。     

电能表印刷电路板耐雷电冲击电压参数测定

对印刷电路板上线路间绝缘强度与线路间距关系进行了实验测定,给出了参考计算式,可作为仪表厂家设计计量仪表内部电路时的一个参考。     

编解码电路在遥测遥控系统中的应用

本文介绍了一种新颖的编解码芯片的工作原理,给出了一个应用实例,讨论了ＵＭ３７５８－１０８在浑水浊度测控系统中的应用,最后给出了实验结果。     

巷道式立体车库设计方案参数优化

建立了巷道式立体车库设计方案参数优化的数学模型,并对其进行了仿真求解。仿真结果为该类型车库选择合理的设计方案提供了量化分析的科学依据。     

微弱光强信号采样电路设计

微弱光信号检测电路应用在许多精密测量仪器中。针对微弱光强信号放大采样问题,分析了传统光电检测电路存在的不足,采用S2387系列光电二极管,结合多级放大电路与T型反馈电阻网络,设计了一种放大倍率可编程的微弱光强信号采样电路。基于对实验数据的分析,通过对前后级放大倍数的合理分配,该电路兼顾了提高响应速度与降低噪声的要求,简洁可靠,适合于光强和波长变化范围大的微弱荧光、散射光和反射光检测。     

基于DSP的闪光焊机电源的数字化设计及电路仿真

介绍了基于数字信号处理器(DSP)的闪光焊机电源的数字控制系统的设计,具体讨论了控制焊机电源的硬件结构和仿真电路设计,重点介绍了闪光焊机电源的主回路、数字同步和触发电路、控制电路的键盘、显示电路和采样电路等。利用Pspice和Multisim对主电路和同步扑捉电路进行了仿真和分析。仿真结果表明,该焊机电源的电路结构性能高,能够满足闪光焊机电源的工艺要求。     

集成电路塑封自动上料系统的研制

为实现集成电路芯片塑封的自动化,设计了自动上料系统。该系统采用多运动同步控制技术实现料片传送、料片排放及料片预热的自动控制;采用大导程滚珠丝杠副和高分辨率伺服系统保证机械手的快速精确定位;采用柔性流道结构,适应不同规格集成电路料片的自动上料;并基于Windows2000开发了专用工控软件。该系统适用于DIP、QFP、SOP、TO等系列集成电路芯片的塑封生产,可显著提高生产效率及产品质量。