Feedback Control: Linear, Nonlinear and Robust Techniques and Design with Industrial Applications
暫譯: 反饋控制：線性、非線性及穩健技術與設計及其在工業中的應用

這本書發展了理解和技能，使讀者能夠解決原創控制問題。對於給定的控制問題，通常的做法是首先嘗試最簡單的暫定解決方案，當這個方案不足以解決問題時，解釋原因並使用更複雜的替代方案來彌補不足，從而達到滿意的性能。這種工作模式使讀者全面了解不同的控制器，並教會他們在滿足特定系統需求時，如何在傳統控制器和更先進的現代替代方案之間做出明智的選擇。重點集中在時間域，涵蓋基於模型的線性和非線性控制形式，以及基於滑模的穩健控制和使用狀態觀測器（如擾動估計）。

《反饋控制》是一本自成體系的書籍，特別注重對基本概念的解釋，必要時會使用詳細的數學推導。書中充分利用圖表來輔助這些概念的解釋，並通過不斷使用來自實際控制應用的例子和問題來活化主題。讀者的學習進一步通過實驗使用完全註解的MATLAB(R)/Simulink(R)模擬環境來增強，該環境可在此插入網址訪問，以生成與文本中涵蓋的所有主題相關的模擬。採用本書的教師也可以從此插入網址下載解答手冊。

《反饋控制》適合作為研究生和最後一年本科課程中包含控制模塊的主要教科書；需要具備普通線性微分方程、拉普拉斯變換、傳遞函數、極點和零點、根軌跡及基本頻率響應分析和基本反饋控制的知識。對於在行業中實踐的工程師和學術控制研究人員來說，它也是控制設計方法的有用參考資料。

My career in control engineering spans forty one years, commencing with control system design and research in the aerospace industry with Marconi Space Systems (Senior Engineer from 1973 to 1980; Principal Engineer from 1980 to 1984) followed by my appointment with the North East London Polytechnic, now the University of East London (Reader in Control Engineering from 1984 to 1994; Professor of Control Engineering from 1994 to the present time)

A milestone in my career was my responsibility for the attitude control system design for the European Space Agencies X-ray astronomy satellite, Exosat. The performance specification was stringent, demanding 1 arc second peak pointing errors about all three control axes using on-off cold gas thrusters, time optimal large angle slewing and extreme robustness against disturbance torques approaching 90% of the available control torques during orbit change thruster firing. Despite Exosat having substantially rigid body dynamics, this led me to originate non-standard nonlinear bang-off-bang state feedback control laws. The result was Europe's first spacecraft attitude control system with software implemented control laws. Following the success of this work, I instigated and carried out research programmes in Marconi Space Systems for the European Space Agency and DERA Space Department (Government research laboratory) aimed at extending my new pedigree of attitude control system to cater for spacecraft containing significant vibration modes due to flexible appendages such as long solar panels. Some of this work formed the basis of my PhD. My personal research in spacecraft attitude control has continued during my time with the University of East London, having attracted several partners in the Institute of Control Sciences of the Russian Academy of Sciences, carrying out joint research, and this led to my election as an Academician of the Academy of Nonlinear Sciences.

During my time with the University of East London, my research has developed into the more general areas of a) robust control (based on sliding mode control rather than H-infinity), which seeks to achieve a specified performance of an automatic control system in the presence of plant modelling uncertainties and unknown external disturbances, and b) model based nonlinear control. Although this research encompasses two main application areas, i.e., spacecraft and electric drives, the control techniques emerging are of general application. Notable is forced dynamic control, a model based control technique, which, through nonlinear state feedback, yields a specified closed-loop performance that may or may not be nonlinear and takes external disturbances into account.

One of my contributions to linear control system design is a pair of formulae for the settling time of control systems with linear closed loop dynamics of arbitrarily high order and coincident closed loop poles, one for the 5% criterion and the other for the 2% criterion. This greatly simplifies and renders more effective the design method of pole assignment. I have found this useful for state observer design as well as the design of various controllers. I have been including the 5% formula in my lectures for several years and some of my European partners are now including it in their control systems teaching. I therefore intend to include this in my book.

It was during the continuation of the spacecraft attitude control work at UEL that sliding modes entailing rapid switching on and off of the gas-jets were found to occur under certain conditions. While this effect was undesirable regarding control valve wear and inefficiency, its potential for achieving closed loop performance independent of the dynamic parameters and external disturbances with continuous momentum exchange actuators was recognised. This also triggered research into sliding mode control for other applications, the most significant being a) an advance in the state-of-the-art vector control methods for a.c. electrical drives (produced on my EU INCO-COPERNICUS project 960169) and b) a novel motion control system for loudspeakers undertaken under a DTI Smart Award.

More recently, I originated two new robust control techniques catering for plant model order uncertainty as well as external disturbances and parametric modelling errors. One is Hyper-Sliding Mode Control, an extension of sliding mode control in which the loop closure using output derivatives beyond the usual 'rank minus one' limit creates additional state variables taking part in the sliding mode that may not be plant state variables. The other is 'Observer Based Robust Control' using my plant model mismatch equivalent input premise in which the problem of controlling an unknown plant is converted to that of controlling a known real time model of an observer by state feedback with pole assignment.

My most recent research is in the direction of reducing the carbon footprint by means of a new, relatively simple and practicable motion controller for electric drives that minimises the wastage of energy due to friction in the driven mechanism, this being predicted to save terawatts of electrical energy consumption throughout industry if employed on a large scale.

I feel that the inclusion of the aforementioned new control techniques in my book as well as the standard ones will add significant value and stimulate the reader's interest and creativity.

During my time with the University of East London I have gained considerable experience of teaching, through creating and delivering three modules in control engineering: Control System Design (final year), Control Applications (final year) for the BEng (Hons) in Electrical and Electronic Engineering and Computer Control for the MSc in Computer Systems Engineering. In addition, I have taught Control System Design and Control of Electric Drives to fourth year MSc students in Warsaw University of Technology, Poland, Wroclaw University of Technology, Poland, Silesian University of Technology, Gliwice, Poland and the University of Zilina, Slovakia. These lectures have always been very well received, students often commenting on the enhanced understanding of control and interest in the subject that they have gained. These fourth year studies are the most advanced taken on the 'continental' MSc courses, the fifth year being largely devoted to a substantial project. I have experience supervising these projects (in the field of control of electric drives) as well as control projects in the final year of the BEng (Hons) in Electrical and Electronic Engineering and the MSc in Computer Systems Engineering at the University of East London.

I have continually taken advantage of student feedback to improve my handouts, which are in the form of books. Over the years, many students have made positive comments about these handouts and my teaching style, having often encouraged me to write a book. I intend to use the chapters of these handouts as the starting point in the development of my book.

我的控制工程職業生涯跨越了四十一年，始於在馬可尼太空系統（Marconi Space Systems）從事航空航天產業的控制系統設計與研究（1973年至1980年擔任高級工程師；1980年至1984年擔任首席工程師），隨後我被任命為東倫敦大學（University of East London，前身為北東倫敦理工學院）的控制工程讀者（1984年至1994年）；自1994年至今擔任控制工程教授。

我職業生涯中的一個里程碑是負責歐洲太空機構的X射線天文衛星Exosat的姿態控制系統設計。性能規範非常嚴格，要求在所有三個控制軸上使用開關式冷氣推進器達到1弧秒的峰值指向誤差，並且在軌道變更推進器發射期間，對擾動扭矩的極端穩健性要求接近90%的可用控制扭矩。儘管Exosat具有相當剛性的剛體動力學，這使我創造了非標準的非線性bang-off-bang狀態反饋控制法則。最終結果是歐洲第一個具有軟體實現控制法則的航天器姿態控制系統。在這項工作的成功之後，我在馬可尼太空系統啟動並執行了針對歐洲太空機構和英國國防研究局（DERA Space Department，政府研究實驗室）的研究計劃，旨在擴展我新的姿態控制系統，以應對由於長型太陽能板等柔性附屬物引起的顯著振動模式。這些工作的部分內容構成了我的博士論文。在我於東倫敦大學的期間，我在航天器姿態控制方面的個人研究持續進行，並吸引了俄羅斯科學院控制科學研究所的幾個合作夥伴，進行聯合研究，這也促成了我當選為非線性科學學院的院士。

在我於東倫敦大學的期間，我的研究發展到了更一般的領域，包括a) 穩健控制（基於滑模控制而非H-infinity），旨在在植物建模不確定性和未知外部擾動的情況下實現自動控制系統的特定性能，以及b) 基於模型的非線性控制。儘管這項研究涵蓋了兩個主要應用領域，即航天器和電動驅動，但所產生的控制技術具有一般應用性。值得注意的是強迫動態控制，這是一種基於模型的控制技術，通過非線性狀態反饋，產生特定的閉環性能，該性能可能是非線性的，也考慮了外部擾動。

我對線性控制系統設計的貢獻之一是針對具有任意高階線性閉環動力學和重合閉環極點的控制系統的穩定時間公式，分別針對5%標準和2%標準。這大大簡化並提高了極點配置的設計方法的有效性。我發現這對狀態觀察器設計以及各種控制器的設計非常有用。我在幾年內的講座中一直包含5%公式，現在我的一些歐洲合作夥伴也在他們的控制系統教學中納入了這一內容。因此，我打算在我的書中包含這一內容。

在東倫敦大學繼續進行航天器姿態控制工作的過程中，發現滑模控制在某些條件下會導致氣體噴射器的快速開關。雖然這種效應在控制閥磨損和效率方面是不可取的，但其在實現獨立於動態參數和外部擾動的閉環性能方面的潛力得到了認可，並且可以使用連續動量交換執行器。這也促使了對其他應用的滑模控制的研究，其中最重要的是a) 對交流電驅動的矢量控制方法的先進技術（在我的歐盟INCO-COPERNICUS項目960169中產生）和b) 在DTI智能獎下進行的揚聲器新型運動控制系統。

最近，我創造了兩種新的穩健控制技術，以應對植物模型階數不確定性以及外部擾動和參數建模誤差。其中一種是超滑模控制（Hyper-Sliding Mode Control），這是滑模控制的擴展，其中使用超出通常“階數減一”限制的輸出導數進行回路閉合，創造了額外的狀態變量參與滑模，這些變量可能不是植物狀態變量。另一種是基於觀察者的穩健控制（Observer Based Robust Control），使用我的植物模型不匹配等效輸入前提，將控制未知植物的問題轉化為通過狀態反饋和極點配置控制已知實時觀察者模型的問題。

我最近的研究方向是通過一種新的、相對簡單且可行的電驅動運動控制器來減少碳足跡，該控制器最小化由於驅動機構中的摩擦而造成的能量浪費，預計如果大規模應用，將在整個行業中節省數十億瓦的電能消耗。

我認為在我的書中納入上述新的控制技術以及標準技術將增加顯著的價值，並激發讀者的興趣和創造力。

在我於東倫敦大學的期間，我積累了相當多的教學經驗，創建並教授了三個控制工程模組：控制系統設計（最後一年）、控制應用（最後一年）針對電氣與電子工程的BEng（榮譽）學位，以及計算機控制針對計算機系統工程的碩士學位。此外，我還在波蘭華沙科技大學、波蘭弗羅茨瓦夫科技大學、波蘭西里西亞科技大學和斯洛伐克日利納大學教授控制系統設計和電驅動控制給四年級的碩士生。這些講座一直受到非常好的反響，學生們經常評論他們對控制的理解和對該主題的興趣得到了增強。這些四年級的學習是“歐陸”碩士課程中最先進的，五年級主要專注於一個重大項目。我在這些項目（電驅動控制領域）以及東倫敦大學電氣與電子工程的BEng（榮譽）學位和計算機系統工程的碩士學位的最後一年控制項目中都有監督經驗。

我不斷利用學生的反饋來改進我的講義，這些講義的形式是書籍。多年來，許多學生對這些講義和我的教學風格給予了積極的評價，經常鼓勵我寫一本書。我打算將這些講義的章節作為我書籍發展的起點。