Programmable Architecture
-Towards Human Interactive, Cybernetic Architecture-

Kensuke Hotta (B.Eng, M.Eng, Msc)
PhD (For the degree of Philosophy of Doctorate in Architectural Design)
Architectural Association School of Architecture and The Open University
The Date of Submission :12 December 2013 (for Examination)


英国建築協会建築学校 & オープンユニバーシティ


I confirm that this is my own work and the use of all material from other source has been properly and fully acknowledged.

Signed Kensuke Hotta, Nov2014



署名; 堀田憲祐, 2014年11月


I would like to express my grateful thanks to my academic supervisors Mr. Michael Weinstock and Dr. George Jeronimidis for the important suggestions and materials given during the development of this thesis. A big thanks to A. Hotta who helped me from the computer programming side. I also want to thank The Union Foundation for supporting my research through a scholarship. In addition I wish to thank my colleagues at the Architectural Association School of Architecture. Finally, I wish to express my deep appreciation to my friends and family.




In this thesis, the Author collaborated with Mr. Akito Hotta who consulted on and implemented the computer programming aspects of this thesis namely the use of JAVA in Chapter 7. He is currently in a PhD course in reliability based information system engineering in Kagawa University, Japan. His major is on multi agent simulation, hence he has experience in making Genetic Algorithms in several programming languages.




This thesis proposes a new strategy for a human interactive-cybernetic architecture, in the context not only of preceding architectural theories of temporal design methods, but also existing theories of mathematics, robotics, and system control using computational techniques addressing both their possible applications and their limitations. Temporal design (time responsive design) requires dynamic control methods in contrast to traditionally static architectural design. True adaptability in architecture necessitates both dynamic hardware and software with the potential for continually renewable forms capable of all possible variations necessary for changing demands and conditions, without having to resort to one teleological optimal solution. Programmable Architecture (PA) consists of both autonomous and subservient systems that maintain a constant homeostasis within its contained environment. The information flow between the Genetic Algorithms (GA) and user input prompts this hybrid system to generate the consequent, ever-changing physical form, while continuously optimizing it for environmental stimuli.

The hardware for PA is an accumulation of self-sufficient machines that is dedicated to the actions of sensing, calculating, and actuating. As a case study for this thesis, a kinetic canopy that is organized using tensegrity-based components of variable forms is proposed. This architectural robot is actuated by shape memory alloy (NiTi) instead of tensile wire, and its control is handled electrically by micro controllers (Arduino, Banzi et al., 2005~). A physical model of this machine has been built at a one-to-one scale and user-tested via mobile devices such as a smartphone.

The software for PA consists of a hybrid control system, which attempts to minimize the difference between the desired objective values and the measured values. This is a combination of automatic responses and user manipulations in order to achieve a faster and higher degree of adaptation. Utilizing the versatility of GA, multiple user inputs are proposed to partially substitute for its purely random mutations (usually GA uses random digits for mutations). This resolves GA’s shortcomings, namely protracted calculation time, lack of adaptability to a fluctuating objective function which represents the ideal condition at any given time, and the ability for ad hoc responses when the system experiences usage overload or random environmental fluctuations. Incorporating the user input, the system can respond rationally to actual conditions unanticipated by the GA. Therefore, the user can concurrently control the system locally, to reflect individual preferences, and contribute to the global optimization and increased efficiency of the system as a whole.

The outcomes of this proposed system based on the proposed hardware and software is compared with static models, such as parametrically optimized forms. An original indicator is established for defining system performance, which aids in evaluating the ability of the system to respond to environmental changes. The thesis makes a contribution in the following 3 areas: first, it addresses the debate about cybernetic architecture, particularly with consideration of real-time optimization and robotic architectural elements that can make real-time decisions and can learn. Second, it looks at methods of human interaction by means of learning algorithms in architectural structures. Thirdly, it considers scientific testing through the physical demonstration of a responsive roof structure.



PAのハードウェアは、自己充足的な機械の蓄積で、センシングをする、計算する、そしてアクチュエイトさせる目的のために用いられる。この論文のケーススタディとして、テンセグリティベースで構成される不定のフォームを使って編成されたキネティックキャノピーが提案されている。このアーキテクチャルロボット(建築的機械)は、張力のあるワイヤーではなく、形状記憶合金(NiTi)によって作動され、そのコントロールは、電気を使ってマイクロコントローラー(アルディーノ, バンツィ他、2005~)で操作される。このマシーンの物理模型は、1対1のスケールで作られ、スマートフォンのようなモバイルデバイスを経由してテストされている。

一方、PAのソフトウェアは、センサー等で測定された値と、要求される目的の値の差を最小限にできるようにハイブリッドコントロールシステムから成っている。これは、より速く適合性を高めるためのオートマティックレスポンス(自動応答)とユーザー操作(ランダムでありながら人間の知覚を利用する)のコンビネーションである。GAの多様性を活用するには、突然変異に単にランダムな数字を利用するより、(知性のある)多数の人間のインプットを活用したほうが、システムの総体としては効率的である。(たいていGAは突然変異のため、ランダムな数字を使用する。) この仕組みは、長引く計算時間や、変動する目的関数に対する速やかな適応(理想的な条件で、導かれる解との差分を小さくする)がむずかしいことなどのGAの短所を解決する。またそれは、システムに多数のインプットが集中し過負荷がかかった際、或いはランダムな環境の変動を受けた際に、臨機応変な対応・反応を可能にする。ユーザーの入力とGAによってシステムは予期しない状況に、適応的でかつ合理的に対応できる。従って、ユーザーは個人の好みを表すための(空間的に)局所的なシステムコントロールができると同時に、このシステムの全体の最適化に貢献し、この効率を高めることができる。


Table of Contents

1 .Introduction
1-1. Introduction
1-1-1. Definition of Original Words (Programmable / Robotic / Responsive Architecture)
1-2. Research Motivation
1-3. Research Field's Background
1-3-1. From the Field of Architecture
1-3-2. From the Control Engineering Field
1-4. Aim and Objectives
1-5. Thesis Overview


1-1-1.独自の言葉の定義(プログラマブル/ ロボティック/レスポンシブ アーキテクチャ)

2 . State of the Art, Background

2-1 . Introduction

2-2. From Architecture

2-2-1. Cedric Price and the Japanese Metabolism Movement
2-2-2. Criticism of Teleological Planning with A.Isozaki and C. Alexander’s idea
2-2-3. A Shortcoming of Parametricism
2-2-4. Three Realized Cybernetic Architecture Projects
2-2-5. Nicholas Negroponte’s Idea

2-3. From Engineering
2-3-1. Robotics
2-3-1-1.Subsumption Architecture (in Robotics)
2-3-1-2. Swarm Robotics
2-3-1-3. Self-Reconfigurable Modular Robots
2-3-1-4. Cooperative/Social Robot
2-3-1-5. Replicative/Evolutionary Robots
2-3-2. Cybernetics
2-3-3. Control System and Control Theory
2-3-3-1. Feedback Control
2-3-3-2. Controller (P, PI, PID controller)
2-3-3-3. Sensing / Measurement and Noise
2-3-3-4. Actuation
2-3-3-5. Stability and Catastrophic Collapse
2-3-4. Deterministic vs Stochastic in prediction and forecasting
2-3-5. Optimization
2-3-5-1. Objective functions (purpose)
2-3-5-2. GA vs others
2-3-5-3. Simulated Annealing
2-3-5-4. Dantzig’s Simplex method
2-3-5-5. Stochastic Diffusion Search/Ant Algorithms
2-3-6. Evolutionary Computing

2-4. From Biology and Biomimetics (Cooperative species)
2-4-1. The Sociable Weaver (Social Birds)
2-4-2. The Termites (Insects' Architecture)
2-4-3. The Dictyostelium (Social Amoeba)

2-5. From Psychology
2-5-1 . Valentino Braitenberg and His Suggest for Temporal Design Method

2-6. From Art
2-6-1. Strand beast by Theo Jansen
2-6-2. Petit Mal by Simon Penny

2-7. Conclusion and Problem Statement



2-2-1.セドリックプライスと日本のメタポリズム ムーブメント
2-2-4.3つの実現化したサイバネティック アーキテクチャ プロジェクト

2-3-4.決定論的予測、予報 vs 推計学的予測、予報
2-3-5-2.GA 対 その他アルゴリズム

2-4-1.ソーシャルウィーバー(ソーシャル バード)
2-4-3.ディクチオステリウム(ソーシャル アメーバ)



3 . Methodology

3-1 . Introduction
3-2 . Philosophy

3-2-1. The Philosophy of Programmable Architecture
3-2-2 . Ubiquitous Architecture
3-2-3 . Programmable Matter for Architecture
3-3. Engineering Tools
3-3-1 . Required Hardware
3-3-1-1 Actuator Properties (Material, Power, Time response, Size, Weight, Max speed)
3-3-2 . Required Software
3-3-2-1. Rhinoceros
3-3-2-2. Grasshopper
3-3-2-3. Galapagos
3-3-2-4. Kangaroo Physics
3-3-2-5. Processing
3-3-2-6. Arduino
3-3-2-7. Traer physics
3-3-3 . Brief Introduction of Genetic Algorithm
3-3-3-1. History of Genetic Algorithm
3-3-3-2. General Strong and Weak Points of Genetic Algorithm
3-3-3-3. The Basic GA Procedure
3-3-3-3-1. Generate Initial Group
3-3-3-3-2. Evaluation
3-3-3-3-3. Selection
3-3-3-3-4. Crossover
3-3-3-3-5. Mutation
3-3-3-3-6. Re-generation and Repetition
3-4 .Conclusion:


3-3-1-1.アクチュエーター プロパティ(材料、力、応答時間、大きさ、重さ、マックスの速度)
3-3-3-3.GA の基本的な手順

4 . Architectural Design Proposal

4-1. Introduction
4-2. Space Reconfiguration
4-3. Electrical Controlled - Cybernetic Architecture
4-4. Flexible Structure: Kinetic Tensegrity Component (Drawing)
4-5. Ever Changing Plan (Drawing)
4-6. The Three Different Scales: Local- Regional -Global
4-7. The Compromise System Between Global-Local as Democracy-Socialism
4-8. The Relation Between Physical Model and Constructive Model
4-9. Conclusion



5 . Data and Analytical Methods

5-1 . Evaluating Performance in ‘Intelligent Systems’
5-2 . Details of Methodology in Previous Experiments
5-3 . Initial Physical Experiments
5-3-1. A Building Envelop Experiment
5-3-2. Kinetic Robot Experiments
5-4 . What is Going to Be Examined
5-5 . Examine, Evaluate and Compare a Fixed and Kinetic Roof
5-6 . What is The Contribution

6 . Experiment 1: Simple Real-Time GA with Grasshopper
6-1 . Introduction
6-2 . Aim
6-3 . Preparation and Mathematical Definitions of the Model
6-3-1. Static Tensegrity Structure
6-3-2. Spring System
6-3-3. Membranes on the Tensegrity Structure
6-3-4. The Sun
6-3-5. Evaluating/ Record
6-4 . The Unique Feature / Limitation of ‘Galapagos’
6-5 . Four Candidates
6-6. Graph Approximation and Visualization
6-7. The result of Comparison of 4 candidates
6-8. The Comparing the computing time for the kinetic candidates
6-9. The Comparison between the different number of resets within kinetic candidates
6-10. Discussion and Conclusion



7 . Experiment 2: Human Assisted GA with Processing
7-1 . Introduction
7-2 . Model Concept
7-3 . Before the Experiment, Preparation and Model Details
7-4 . Model Execution and Evaluation
7-5 . Argument and Conclusion


8 . Model development and Conclusion

8-1. Answer to Research Questions
8-2. Future Work, Scaling Up Towards Real Buildings
8-3. Future Work, Towards Physical Experiment
8-4. Future Work, Addressing Various Environmental Stimuli and Other Concerns
8-5. Future Structures



9 . Bibliography


10 . Appendix
10-1. Grasshopper definition
10-2 . The table for Experiment 1 in Chapter 6
10-3 . Table for experiment 2 on Chapter6
10-4. Table for experiment 3 in Chapter 6
10-5. Table for experiment 1 in chapter7
10-6 . Processing Program in Chapter7

10. 付録
10-1. グラスホッパーの定義
10-2. 6章の実験1の表
10-3. 6章の実験2の表
10-4. 6章の実験3の表
10-5. 7章の実験1の表
10-6. 7章のプロセシング・プログラム

List of publications, presentations and contests


  • Kinetica Museum. (2012) Kinetica Art Fair 2012, London: Colville Place Gallery, ISBN 978-09536240-9-6, p.10

  • Kinetica Museum. (2013) Kinetica Art Fair 2013, London: Colville Place Gallery, ISBN 978-0953624096, p.20

  • T.Ito. Bijutsu Techo (ed.) (2013), Bijutsu Techo May 2013, Tokyo: Bijutsu Techosha, ASIN: B00C2HZHAC, pp.110-111


  • 2012: Architectural Association Symposium Translate the Intangible, UK

  • 2012: Kinetica Art Fair 2012, UK

  • 2013: Kinetica Art Fair 2013, UK

  • 2013: Japanese Junction 2013, Japan


  • 2010: 1st place, Okayama Kibi Line LRT Station Competition, Japan



  • キネティカミュージアム.(2012) キネティカ アートフェア2012、ロンドン:コルヴィルプレイス ギャラリー、ISBN 978-09536240-9-6,p.10

  • キネティカミュージアム.(2013) キネティカ アートフェア2013、ロンドン:コルヴィルプレイス ギャラリー、ISBN 978-0953624096,p.20

  • T.Ito.美術手帖(ed.) (2013),美術手帖2013年5月、東京:美術手帖社、ASIN:B00C2HZHAC,pp.110-111


  • 2012: AAシンポジウム・トランスレート・ザ・インタンジブル、英国

  • 2012: キネティカ アート フェア 2012、英国

  • 2013: キネティカ アート フェア 2013、英国

  • 2013 :ジャパニーズ ジャンクション 2013、日本


  • 2010: 1位、岡山吉備線 LRT駅コンペティション、日本

1-1. Introduction

There are two different meanings associated with the word “architecture”. The first relates to “the style and design of a building or buildings” and the other to “the structure of a computer system and the way it works” from Longman dictionary (Ed.Various, 2009). In this thesis the former is described as ‘architecture (building)’, and is considered the “hardware”, the latter is described as ‘architecture (system) ’and is considered the “software”. This proposal will attempt to re-connect these two words because of the upsurge in computational methods, not only as an extension of the designer’s hand - such as a drawing software - but also as an extension of the designer’s intelligent, brain-like functions (mind) - such as intelligent controllable tools.

Programmable Architecture as discussed in this research proposes a new strategy for cybernetic architecture defined as a multi-scaled system that communicates with architectural components, the smallest elements are interconnected with humans by devices such as smartphones. Through both software and hardware, it has the ability to change its shapes during its interaction.(Fig1-1-1) The important thing is to ensure that the architectural space (building and system) is somehow controllable by human agents.

The core challenge is to make the hardware a lattice of discrete machines (which consist of self-contained components) that integrates numerous computers dedicated to sensing-calculating-actuating, each making its own decisions in order to produce an interactive interface. True adaptability or sustainability of architecture can result from such a system.


「アーキテクチャ」という言葉にはふたつの意味がある。ひとつは構造物や建築物のスタイルやデザインに関連するもの、そしてもうひとつは、コンピュータシステムの構造とその働きである。(ロングマン現代英英辞典, ,2009年版)  この論文では、前者は建築物(物理的建造物)を表し、これをハードウェアと呼ぶこととする。後者は建築システムと表現しソフトウェアと呼ぶこととする。この提案は、今日のコンピューテション手法の隆盛によって、この二つの言葉を再び接続することを試みる。それは、設計者の手の延長線上にある図面ソフトのようなものだけでなく、設計者の知的機能の延長としての役割を担う使い方を意味する。また、これはコンピュータが知的な協働のための道具となるような可能性を示唆する。



The thesis makes a contribution in below 3 points

- to the debate about cybernetic architecture, particularly real-time optimisation, and robotic architectural elements that can make real-time decisions and can learn.

- to methods of human interaction with learning algorithms in architecture

- to scientific testing through physical demonstration of a responsive roof structure





fig.1-1, 1 , A diagram of proposed Architecture (both in building and system and those connections.)


1-1-1 : Definition of Original Words

Several key phrases are defined below. It’s worth noting that the word ‘Architecture’ is used, in this thesis, in it’s traditional context of building and construction, not as a reference to a structure of logic or as an algorithm in the computing field.

1-1-1: オリジナルの言葉の定義


An ‘Architectural Machine’ is an architectural structure (building) which incorporates some kind of mechanism such as robotic features or mechanical engineering techniques. This contrasts with a traditional structure (building) which is a static object. In contrast to ‘Robotic Architecture’, this system does not have a metaphysical system such as a computer.

「アーキテクチャル・マシーン」とは、ロボティックな特徴や機械工学技術のような何種類かのメカニズムを合体させた建築の構造(アーキテクチャル・ストラクチャ)である。これは静的なオブジェクトである伝統的な建築物とは対照的なものである。「ロボティック ・アーキテクチャ」に比べ、このシステムはコンピューターのような形而上のシステムを持たない。

‘Robotic Architecture’ is a cybernetic architectural system consisting of a building and its control system. This is a combination of a physical structure and a metaphysical system. As with a robot, there are various degrees of automation, creating a system that has different degrees of intelligence. This system is a kind of automata; depending on its intelligence it may be more or less responsive. It is possible to achieve higher functions such as the distinction between right and wrong responses, and even to renew its own system (Autopoiesis). However up to the present (2014), these systems lack in intelligence.


‘Responsive Architecture’ is a primitive cybernetic architectural system which consists of a building and its control system which have a monotonous (or patterned) response system. This system is a simple closed loop system that can respond to stimuli from humans or the environment. It’s responses are programmed and fixed in advance creating a system with limited adaptability. If the stimulus levels or types change, an administrator, human most likely, needs to re-program the system. This system sometimes is incorporated into ‘Robotic Architecture’ (defined above). But also it can be used in other types of response systems such as a material based system.


‘Programmable Architecture’ is a cybernetic, responsive architecture (building) which consists of robotic architecture and a flexible control system which has an interaction system (interface) between its autonomous software and its human users. This ‘autonomous’ system can be controlled by various methodologies and algorithms, as well as accepting intervention or being overridden by its human users. This hybrid system has a flexible and intelligent ecology. ‘Programmable’ here is polysemic referring to the control system which is program-able by a computer script, program-able in terms of its architectural functions which can be altered by changing its shape, and finally referring to the fact that it is control-able by the end user who may wish to alter an existing program or initiate a new program.


1-2. Research Motivation

Since this is not a conventional architectural field, it is difficult to find a specific definition for concepts such as time-based design and the meaning of ‘Programmable in architecture ’or even ‘Metabolism in architecture’. However, user-participation is considered central to the architectural design concepts developed in this work. As a familiar example of this, a house renovation, including enlarging or reducing space/volume can be used to explain these concepts. Dwelling surveys carried out in West Africa in 2007 (Hotta, 2008) show that the local inhabitants proceed to modify their own dwellings (fig1-2-1). The local woman breaks part of a mud wall, and patches it with wet mud.



Fig 1-2,1 , A local woman plastering her house with wet mud. They do not have architectural profession, but residents mend themselves. This picture is taken in Kion village, Lele Tribe, in BurkinaFaso ,2007, at West African Survey, by Fujii Lab, The University of Tokyo . Author (K.Hotta) participated in this research trip.


However in this work, ‘renovation’ does not just mean renovating size by adding a room, but also the use of adaptability to provide an equivalent architectural function. Surprisingly, in the 1960's, Mr A.Isozaki , who is Japanese architect, was already aware of this issue which placed him in a critical position with respect to the Japanese Metabolist’s Movement (see Section 2-2). The problem is: the specialist’s design cannot help but be a teleological structure as opposed to a vernacular procedure. (Vernacular procedure is architect-less architectural design, the lay-person frequently make and modify their buildings without planning) The Metabolists (Isozaki, 1963.) tried to avoid those specialist’s subjective design methods using autonomous and time-based design methods (Time-based design is the architectural system that has the ability to change after it is built), but they fell into the same trap. True autonomous design should be handled by the user.


1-3. Research Field's Background

1-3-1. From the Field of Architecture

In recent years, the key word 'adaptability' is increasingly used in the field of emergent architectural design. Two recent book titles are “Adaptive Ecologies"(Theodore, S., Frazer, J., Schumacher, P., 2013) and "Unconventional Computing: Design Methods for Adaptive Architecture"(Armstrong, R.(Au), Simone, F. (Ed)). Also in ACADIA (The Association for Computer Aided Design in Architecture), the most famous conference in the computational design field, the title of its 2013 conference was 'Adaptive Architecture’.



近年、「adaptability(適応性)」というキーワードは、創発的な建築デザインの分野においてよく使われている。最近の2冊の本のタイトルは「AdaptiveEcologies(適応性生態)」(Theodore、S.、Frazer、J.、Schumacher、P.、2013)と「UnconventionalComputing:Design Methods for Adaptive Architecture(型破りなコンピューティング:適応性建築の設計方法)」(Armstrong、R.(Au)、Simone、F 。(Ed))。また、コンピューテーショナルデザイン分野で最も有名な会議であるACADIA(Association for Computer Aided Design in Architecture)でも、2013年の会議のタイトルは「AdaptiveArchitecture(適応性建築)」であった。

Fig 1-3-1,1: A diagram of Contemporary Architectural Concepts.
Considering non-static architecture (building), terms related to emergent architecture have appeared which could be arranged in a ranking order of complexity, from primitive to higher level functionality: ‘time-based design’, ‘event-based design’, ‘responsive design’, ‘interactive design‘, ‘adaptive design‘, ‘intelligent design‘ (Sherbini and Krawczyk, 2004). In recent times, in addition, new keywords have also appeared (Sterk, 2009a) associated with concepts such as ‘cybernetic machine’, ‘kinetic architecture’, ‘user participation’, ‘discrete model‘.

非静的アーキテクチャ(建物)を考慮すると、複雑さのランク付け順に並べることができるような創発的建築に関連する用語が登場した。「時間ベースの設計」、「イベントベースの設計」、「レスポンシブル設計」、「相互作用性設計」、「適応性設計」、「知的設計」(Sherbini and Krawczyk、2004)。さらに、最近では、「サイバーネティックマシン」、「キネティックアーキテクチャ」、「ユーザー参加」、※「離散的モデル」などのコンセプトに関連する新しいものも登場している(Sterk、2009a)。

There are many approaches to making architecture (both buildings and systems) adaptive and sustainable. (Fig1-3,1) Most contemporary architecture uses scientific approaches based on mathematics, physics, and computational tools and through experimentation is able to achieve higher levels of adaptability against ever changing circumstances. However, in considering the keyword ‘adaptability’ in architectural design, it is critical to discuss what adaptability is for. Also there is a problem that the high 'adaptability' is used for better thing in this context without description. It is problematic to speak of high ‘adaptability’ without a description of what the nature and benefits of the adaptability are. This leads to the question - why is adaptability needed in the design process. To make this logic clear is a critical aspect of the design research.


In this research it was necessary to narrow the approach to certain aspect of the design. In this thesis, environmental adaptability is the centre of discussion. The aim is for an architecture with higher environmental adaptability, and to develop an architectural design methodology that will address shape, systems, and devices that constitute the building. In addressing adaptability a morphological method is taken though there are thousands of the methodologies that could result in a adaptable architecture. The idea of shape-adaptive architecture, which consists of dynamic components, has been gaining in popularity (Schumacher, 2010a). Component-based design methods, inspired by biology, have been present in German architectural design as exemplified by Frei Otto. However, because of the development of computational approaches, it has been re-interpreted within the contemporary period through the Emergent Technology and Design Programme at the Architectural Association (Hensel, M., Menges, A., Weistock, M., 2010). After a decade its popularity has also been enhanced with contributions from the theoretical side.(Hensel, M. and Menges A., 2007)

この調査では、デザインの確実な面に絞ってアプローチする必要がある。この論文では、環境への適応性が、議論の中心となる。その狙いは、建築が、環境へのより高い適応性をもつこと、そして、建物を構成する形、システム、そしてデバイスを扱う建築デザイン方法論を発展させることである。適応性に対処する際には、形態学的な方法が採用されるが、適応可能な建築をもたらす可能性のある方法論は数千とある。動的要素で構成される形状適応型建築のアイデアが人気を集めている(Schumacher、2010a)。生物学に触発されたコンポーネント(構成要素)ベースの設計手法は、フライオットーによって例示されているようにドイツの建築設計にある。しかし、計算アプローチの開発により、AAスクールのEmergent Technology and Design Program(Hensel、M.、Menges、A.、Weistock、M.、2010)を通じて、現代で再解釈された。 10年後、その人気は理論的な側面からの貢献を受け強化されることとなった。(Hensel、M. and Menges A.、2007)

1-3-2. From the Control Engineering Field

The ‘Control Engineering’ field is an interdisciplinary field seeking stable behaviour with a cybernetic aspect, in various systems. 'Control Theory’ in particular deals with dynamic systems from a mathematical point of view. All theory consists of 3 aspects namely 'the representational model', 'the analytic methodology' and 'the control design'. Recently, Control Engineering methodologies have expanded significantly alongside advancements in Control Theory. Because of technological advancements, 'Post Modern Control Theory ' and 'Intelligent Control Theory' have become increasingly important since the 1980's in contrast to 'Classical Control Theory' and 'Modern Control Theory’.

A brief history of this theory is described here. The first so called Automatic Control Systems were developed before Christ. For example in Alexandria, Egypt there was a water-clock which had a feedback control system. Automata such as dancing figures became popular in Europe in the 17th and 18th centuries for entertainment. These systems were the typical 'Open-loop Control' systems, which repeated the same task over and over. In contrast the 'Closed-loop' control device was first invented by C. Drebbel around 1620, as temperature regulator for a furnace. J Watt is famous for inventing the centrifugal fly-ball governor for steam engines in 1788. J.C. Maxwell first described control systems with differential equations on his paper "On Governors". (Maxwell, J.C.,1868) Edward John Routh and Adolf Hurwitz analyzed system stability using differential equations in 1877. This resulted in the Routh–Hurwitz theorem. This demonstrated the importance of mathematical models and started mathematical system theory though not in a convincing way.

Around World War 2, mechanical applications of control devices became mainstream being used in flight control, fire control, guidance systems, sidewinder missiles, ship stabilizers, even in electronics. This technical competition shifted into the Space Race during the Cold War. Building on progress in stochastic, robust, adaptive and optimal control methods, this theory made significant progress. Referred to as 'Classical Control Theory', it was formally organized in the 1950's representing the closed-loop systems dominance over open-loop systems. following Classical Control Theory, 1) in the time domain differential equations are used, 2) in the complex-s domain the Laplace transform is used and 3) in the frequency domain one uses a transformation from the complex-s domain. In this way, single input and output (SISO) are dealt with in a linear system called the 'Transfer Function'. When the frequency domain approach is taken, the Laplace transform is frequently used on the variables. 'PID control' or short proportional-integral-derivative is one representative example of this. These theories are still at the centre of the field of Industry. 'Modern Control Theory' is distinguished from Classical Control Theory through its use of time-domain 'State Space' representation (also known as the "time-domain approach") in contrast to 'the frequency domain analysis' of the ‘Classical Control Theory’. The sets of inputs and outputs are represented as first-order differential equation. Unlike the frequency domain approach, the use of the state space representation is not limited to systems with linear components and zero initial conditions. “State space" refers to the space whose axes are the state variables. The state of the system can be represented as a vector within that space. (Donald M Wiberg, 1971). Because of this, it can be applied to more complex problems. In the 1960's, optimized output feedback was popular in research. In the 1970's, systems with a combination of sensors and optimized regulators became the centre of academia. It resulted in a variety of regulators.

In terms of recent development, there are various types of methodologies referred to as 'Post-modern Control Theory'. The most common examples are Adaptive control, Hierarchical control, Optimal control, Predictive Control (MPC) and Linear-Quadratic-Gaussian control (LQG), Robust control, Stochastic control, Energy-Shaping control and Self-Organized Criticality control. Every control system must guarantee first the stability of the closed-loop behaviour. For linear systems, this can be obtained by directly placing the poles. Non-linear control systems use specific theories (normally based on Aleksandr Lyapunov's Theory) to ensure stability without regard to the inner dynamics of the system. The ability to address different specifications varies according to the model considered and the control strategy chosen. 'Intelligent Control Theory' uses various AI (Artificial Intelligence) computing approaches such as neural networks, Bayesian probability, fuzzy logic, machine learning, evolutionary computation, Intelligent agents (Cognitive/Conscious control) and genetic algorithms to control a dynamic system. These methodologies have become popular not only because of computational advancement but also because of the development of algorithmic-software. A feature of these methodologies is that when the model or controllers are constructed, they don’t require a specific physical character giving them great versatility.

1-4. Aim and Objectives

The aim of this thesis is to demonstrate that the architectural fabric made by programmable architecture (PA) can reconfigure space in order to control its environment. This set space is ephemeral but can support the various activities that are compose human lifestyle. Physical architecture interferes with the environmental elements such as light (illumination), sound (volume and frequency), air (direction, speed and heat) etc. Programmable architecture will control those elements by changing its physical form. By changing form, this architecture will make different types of layered spaces. In this proposal the space is that underneath a canopy. This approach to affordance is based on the hypothesis that environmental conditions can induce people to take specific actions. For example reading in the library-how is it possible to reconfigure the space and induce the action? Though human action is unpredictable, it is possible to prepare circumstances which encourage the desired behaviour. In this instance, there is a comfortable environmental range of conditions for reading. For instance, there should be no rain, it shouldn’t be too dark for visibility, it should be silent, there should be a calm wind or no wind, extreme ranges of temperature need to be avoided etc. Thus this architecture (a combination of building and system) will encourage human activity. To support this argument, a new paradigm for spatial reconfiguration policy needs to be defined. Rather than planning based on spatial functions, PA is designed as a system which can fulfil the pluripotent functions of day to day living and working. Any architecture (building) has functions; functions are a way of using space in this context. In architectural design, traditionally most of architecture (building) is planned, drawn and built based on this principle. However in this proposal the functions are ephemeral, even it after being built the building’s functions are ever changing in the same way as the events in a plaza. Users are searching for an appropriate space which has an optimal environment for a specific action. When this action is complete, they are encouraged to engage in a new activity or simply leave this space. However this may sometimes be inconvenient for stable users. So In the proposed PA system the user can control the character of space in a more advanced way creating spaces environmentally appropriate for their activities.

This thesis’ objective is to design and test an architectural fabric (a combination physical structure and system) which can follow an objective function more tightly than optimal or non-optimal conventional static structural fabrics. In here the objective function is based on an environmental factor, the amount of illumination. (Ideally this experiment should be done with each of the above environmental factors, but those are omitted because of limited time and space) As in all control theory, the system's stability is measured as the difference between the desired value and the measured (sensor) value. The more stable system has a smaller difference over a predetermined period of time. (In this experiment one day was used). This proposed architectural system will test whether it is able to fulfil the chosen environmental requirements over the period of one day. This result will lead to determining the sustainability of the structure with regards to its functional flexibility as well as its energy consumption over the lifespan of the building.

1-5. Thesis Overview

In chapter 2, several seminal literatures are reviewed in the context of proceeding among architectural theories and computational theories especially control theory, and other emergent fields on temporal design methods while addressing their limitations. The temporal design methods presented by the likes of Metabolists and Cedric Price offered alternative approaches to the static forms of architecture, where predominant discussions were inclined to address adaptability solely in the phase of planning as a representation of frozen time. When materialized, the resultant static architecture had already lost most of its flexibility and sustainability. The current computational design methods, including parametricism, also typify these issues. Yet true adaptability in architecture necessitates both dynamic hardware and software with the potential for continually renewable forms capable of all possible variations for the changing demands and conditions, without having to resort to the one supposedly optimal solution.

In chapter 3, hypothesis and following research questions are introduced. then, Programmable Architecture (PA) introduces a new strategy for robotic architecture as an intelligent system, consisting of both autonomous and subservient schemes that maintain a constant homeostasis within its contained environment. Transmissions between genetic algorithms (GA) and user input prompt this hybrid system to output the consequent, ever-changing physical form. The contained environmental conditions are maintained more effectively than the previous models where GA and user input operate disparately.

In chapter 4, a concrete research approach and physical design will be introduced. The hardware for PA is an accumulation of self-sufficient machines that is dedicated to the actions of sensing-calculating-actuating. Each local machine makes its own simple decisions, which collectively turns into a larger problem-solving machine, or architectural robot, that simultaneously takes central orders into account. This robot manifests itself as a self-supporting skin structure, in which numerous machines are embedded. As a case study for this thesis, the machine that is organized with tensegritic components of variable forms is proposed. A model of this machine is built at one-to-one scale and tested via the electrically controlled and wirelessly connected microcomputer chip called Arduino.

In chapter 5, data and analytical methods will be discussed. Referencing several previous experiments done by author, the meaning of experiments in following chapters are explained. Based on the illumination which functionally required, fluctuating objective function are set. The difference between measured value and desired value are compared and discuss how can it be minimized. Also GA will be explained, its procedure and feature including positive point and negative points.

In chapter 6, first experiment which done by pure GA with grasshopper is shown. Several cause, why GA does not work effectively, are assumed and tested in different settings, though results are unsavory. Hence this failure will highlighting typical GA's shortcomings: protracted calculation time, adaptability for fluctuating objective functions, which represents the ideal condition at any given time, and the ability for ad hoc responses when the system experiences usage overload or environmental irregularities.

In chapter 7, reflecting previous chapter, hybrid system consists of automated GA and manual user inputs are examined. The software for PA consists of operation system and control system. The latter subsists on a combination of automatic responses and user manipulations for faster and higher degree of adaptations. Utilizing the versatility of GA, this model applies multiple user input to partially substitute its purely random mutations, thus resolving GA’s shortcomings. Incorporating the anonymous user input, the system can respond rationally to actual conditions unanticipated by GA. Therefore user input simultaneously controls the system locally to reflect individual preferences and contribute to the global optimization and increased efficiency for the system as a whole.

In chapter 8, discussion and conclusion are described. Through the example of proposed hardware and software, this research provides a case of defining system performance measurements using original indicators, which aids in evaluating the ability of the system to react to environmental changes. The outcomes of this proposed hybrid system will be compared with a computationally static model, as in a case of parametrically optimized form, in addition to testing different arrangements, i.e. varying ratios of user input versus random mutations, within the dynamic model.