David V. Smith (1943-2006).

Presents an obituary for David V. Smith, who succumbed to a brain tumor on September 30, 2006 at the age of 63. He was Simon R. Bruesch Professor and chair of the Department of Anatomy and Neurobiology and the director of the Neuroscience Institute at the University of Tennessee Health Science Center (UTHSC). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

立式旋风锅炉的燃烧自适应控制

分析了立式旋风锅炉的燃烧特点和燃烧系统动态特性，讨论了它的软硬件构成及其功能。     

Generalized multi-scale control scheme for cascade processes with time-delays

The cascade control is a well-known technique in process industry to improve regulatory control performance. The use of the conventional PI/PID controllers has often been found to be ineffective for cascade processes with long time-delays. Recent literature report has shown that the multi-scale control (MSC) scheme is capable of providing improved performance over the conventional PID controllers for processes characterized by long time-delays as well as slow RHP zeros. This paper presents an extension of this basic MSC scheme to cascade processes with long time-delays. This new cascade MSC scheme is applicable to self-regulating, integrating and unstable processes. Extensive numerical studies demonstrate the effectiveness of the cascade MSC scheme compared with some well-established cascade control strategies.     

基于80 C196KC单片机的Smith伺服控制器

讨论全数字伺服系统中的时间滞后，通过Smith预估控制器补偿系统中的时间滞后，提出一种应用80C196KC单片机的宽范围、高精度调速的控制方案及算法。对于非滞后系统采用Smith伺服控制器，可以简化系统、提高性能指标。     

清香木姜子的化学成分Ⅱ

利用硅胶柱层析分离及与标准品对照等方法从清香木姜子枝叶中分离得到4个化合物,1H NMR、13C NMR等技术及理化性质鉴定为:黄堇碱(1)、二十二酸(2)、二十六酸(3)、三十酸(4)。以上化合物均系首次从该植物中分离得到。     

Smith模糊PID匀速升温控制策略研究

针对电加热炉匀速升温过程模型建立困难、调节过程滞后等问题,提出了一种基于炉体散热补偿的Smith模糊PID控制算法。通过炉体散热补偿建立针对被控量升温速率的一阶线性纯滞后模型;采用Smith预估器消除纯滞后特性带来的影响,提高系统的稳定性,加快调节过程;引入模糊PID控制,克服Smith预估补偿环节鲁棒性差的弱点,实现参数的自适应调整,并提高了稳态精度,实现了高精度的匀速升温控制。试验结果表明,该控制策略的控制偏差低于5%,明显优于常规PID控制。     

On input‐to‐state stability‐based design for leader/follower formation control with measurement delays

This paper addresses the design of low‐level controllers for leader–follower formations of nonholonomic vehicles in the presence of bounded measurement delays. The concept of input‐to‐state stability is extended to encompass the effect of bounded delays and restrictions on the input. A method is proposed to integrate a Smith predictor in a backstepping design on the basis of nested saturations and nonlinear small‐gain assignment, which allows for time delays in the feedback loop. Robustness analysis under uncertain bounded time delays is provided, and design tradeoffs resulting from the use of bounded controls are discussed. Illustrative simulations are shown to validate the design and robustness analysis in the context of a simple leader–follower trailing control problem. Copyright © 2012 John Wiley & Sons, Ltd.     

基于模型参考自适应Smith预估器的反馈式AGC厚度控制系统

针对具有纯时间延迟特性的反馈式AGC(automatic gauge contro1)系统,利用Smith预估器对纯时间延迟具有补偿作用的原理,建立了模型参考白适应Smith预估器反馈式AGC控制系统模型,给出了控制系统结构.推导了自适应调节律和设计算法,结合预估器模型,计算得到轧件出口厚度偏差值的表达式.仿真结果表明,模型参考自适应Smith预估器反馈式AGC系统对铝薄板带材轧制出口厚度偏差控制具有很好的控制效果,解决了反馈式AGC厚度控制由于纯时间延迟特性对控制性能产生很大影响的问题,消除了出口厚度波动现象,响应速度加快,可以满足高精度铝薄板带材轧制生产的控制要求.     

一类时滞系统的自校正模糊Smith控制器设计

Smith预估控制是解决时滞系统控制的有效方法,但其对系统模型参数的精确要求限制了其应用.而模糊控制本质上属于PD控制,无法消除系统的稳态误差.文中设计了一种自校正模糊Smith 控制器,结合模糊控制、Smith预估器及自校正控制的优点,既保持了模糊控制鲁棒性较强的特点,又消除了系统的稳态误差,且改善了系统的动态性能.仿真结果表明了自校正模糊控制器的有效性和优越性.     

A local construction of the Smith normal form of a matrix polynomial

We present an algorithm for computing a Smith form with multipliers of a regular matrix polynomial over a field. This algorithm differs from previous ones in that it computes a local Smith form for each irreducible factor in the determinant separately and then combines them into a global Smith form, whereas other algorithms apply a sequence of unimodular row and column operations to the original matrix. The performance of the algorithm in exact arithmetic is reported for several test cases.