Adaptive terminal sliding mode control for high-order nonlinear dynamic systems

ＩＮＴＲＯＤＵＣＴＩＯＮＣｏｎｓｉｄｅｒａｂｌｅａｔｔｅｎｔｉｏｎｈａｓｂｅｅｎｆｏｃｕｓｅｄｏｎｔｈｅｃｏｎｔｒｏｌｐｒｏｂｌｅｍｏｆｕｎｃｅｒｔａｉｎｄｙｎａｍｉｃａｌｎｏｎ ｌｉｎｅａｒｓｙｓｔｅｍｓｓｕｂｊｅｃｔｔｏｅｘｔｅｒｎａｌｄｉｓｔｕｒｂａ     

创新之路，我们才刚刚开始

1989年初我从日本留学回到浙大工作。之初．我觉得应该像在国外一样仅仅从事基础性研究工作，那样既体现水平．又相对轻松。但几年过后觉得中国不仅需要高水平的创新性成果．同时需要科技推动经济的发展．解决中国经济快速发展过程中许多科学技术的关键问题。自当时的国家计委（现国家发展与改革委员会）在浙大设立了工业自动化国家工程研究中心（1992年）后，我更加体会到科技与经济的结合是多么重要。     

CONTINUOUS ROBUST TRACKING CONTROLLERS FOR A CLASS OF UNCERTAIN NONLINEAR DYNAMICAL SYSTEMS

ＩＮＴＲＯＤＵＣＴＩＯＮＩｎｒｅｃｅｎｔｙｅａｒｓ,ｒｏｂｕｓｔｃｏｎｔｒｏｌｏｆｄｙｎａｍｉｃａｌｓｙｓｔｅｍｓｗｉｔｈｓｉｇｎｉｆｉｃａｎｔｕｎｃｅｒｔａｉｎｔｉｅｓｗａｓｗｉｄｅｌｙｒｅｓｅａｒｃｈｅｄ .Ｍａｎｙｎｅｗａｐｐｒｏａｃｈｅｓｈａｖｅｂｅｅｎｐｒｏｐｏｓｅｄｂａｓｅｄｏｎｓｏｍｅｄｅｓｉｒｅｄｐｅｒｆｏｒｍａｎｃｅｓ.ＴｈｅＬｙａｐｕｎｏｖｆｕｎｃｔｉｏｎｃｏｍｍｏｍｌｙｕｓｅｄｔｏｓｙｎ ｔｈｅｓｉｚｅｔｈｅｃｏｎｔｒｏｌｌｅｒ(Ｌｉ,1 996;Ｙａｌｌａｐｒａｇａｄａｅｔａｌ.,1 996…     

Optimization of block-floating-point realizations for digital controllers with finite-word-length considerations

INTRODUCTIONDuetothefinitewordlength (FWL)effect,acasualcontrollerimplementationmaydegradethedesignedclosed loopperformanceorevendestabilizethedesignedstableclosed loopsys tem ,ifthecontrollerimplementationstructureisnotcarefullychosen .Theeffectsoffinite…     

A SISO mixed H2/l1 optimal control problem and its solution

Study of the SISO mixed H2/l1 problem for discrete time systems showed that there exists a unique optimal solution which can be approximated within any prescribed missing error bound in l2 norm with solvable suboptimal solutions and solvable superoptimal solutions.     

Adaptive terminal sliding mode control for high-order nonlinear dynamic systems

An adaptive terminal sliding mode control (SMC) technique is proposed to deal with the tracking problem for a class of high-order nonlinear dynamic systems. It is shown that a function augmented sliding hyperplane can be used to develop a new terminal sliding mode for high-order nonlinear systems. A terminal SMC controller based on Lyapunov theory is designed to force the state variables of the closed-loop system to reach and remain on the terminal sliding mode, so that the output tracking error then converges to zero in finite time which can be set arbitrarily. An adaptive mechanism is introduced to estimate the unknown parameters of the upper bounds of system uncertainties. The estimates are then used as controller parameters so that the effects of uncertain dynamics can be eliminated. It is also shown that the stability of the closed-loop system can be guaranteed with the proposed control strategy. The simulation of a numerical example is provided to show the effectiveness of the new method. Project supported by the National Outstanding Youth Science Foundation of China (NSFC:69725005) and the Zhejiang, Provincial Natural Science Key Foundation of China (ZD9905)     

浅谈高层建筑混凝土产生裂缝的原因

随着我国经济的快速发展,高层建筑逐渐成为现代城市的重要部分之一。混凝土又作为高层建筑主要的结构形式,影响着整个建筑工程质量、寿命及安全性,所以混凝土的质量好坏受到业内广泛关注。混凝土本身是一种非均质脆性材料,由骨料、水泥和水组成。而结构中常出现开裂问题,裂缝会大大降低抗渗能力,直接导致耐久性的下降。而高层建筑混凝土产生裂缝的因素多种多样,本文就当前我国高层建筑混凝土产生的裂缝的原因进行分析研究。     

浅谈高层建筑混凝土裂缝的防治对策

随着我国经济的快速发展,高层建筑逐渐成为现代城市的重要部分之一。混凝土又作为高层建筑主要的结构形式,影响着整个建筑工程质量、寿命及安全性,所以混凝土的质量好坏受到业内广泛关注。混凝土本身是一种非均质脆性材料,由骨料、水泥和水组成。而结构中常出现开裂问题,裂缝会大大降低抗渗能力,直接导致耐久性的下降,本文就当前我国高层建筑混凝土产生的裂缝防治措施进行分析研究。     

褚健:协同创新是大学的新方向新使命

我国在产学研结合、加快科研成果向生产力转化方面做了不少工作.高校也积极参与其中,但是收效不是很理想.究其原因,我认为是政府、高校、企业、金融等各方面的深层机制没有大的改变. 高校的兴奋点在于出成果、出论文,发表在国际高层科技信息平台上;企业则囿于自身水平限制,缺少深度创新的实力与眼光;而地方政府更感兴趣的是经济总量与税收.搞协同创新,就要秉持新的理念,打破原有机制,创造新的机遇.高校不仅要树立新的发展观念,还要运用智慧,付诸实践,在现有条件下有所承担.