The Hidden Technology

2. Electronic Stability Program (ESP) is a new safety system which guides cars through wet or icy bends with more safety…. The key is a yaw-rate sensor, which detects vehicle movement around its vertical axis, and software which recognizes critical driving conditions and responds accordingly.

3. The Hidden Technology • J Widely used • J Very successful • L Seldom talked about • Except when disaster strikes • Why? • Perhaps easier to talk about devices than ideas

4. ControlThe Hidden Technology K. J. Åström Lund Institute of Technlogy Lund University Sweden

5. Engineering Education Followed the pattern of emerging industries in the last century: Civil Engineering, Mining, Mechanical, Chemical, Electrical. New fields such as Automatic Control and Systems which are not tied to a particular industry have appeared in this century.

6. 1. Introduction 2. A Brief History 3. State of the Art 4. The Future 5. Conclusions

7. A Brief History Early use in many fields Process control Vehicle control Communication Servomechanism Theory Consequences The Second Wave Maturity?

8. Industrial Process Control Windmills Mead 1787 Steam Engines 1788 Governors 1890 Water Turbines 1893 Tolle’s Book 1905 The PID Controller 1930

9. Wilbur Wright 1901 We know how to construct airplanes. Men also know how to build engines. Inability to balance and steer still confronts students of the flying problem. When this one feature has been worked out, the age of flying will have arrived, for all other difficulties are of minor importance

10. A Quiz! Robot Piloted Plane makes Safe Crossing of the Atlantic No hands on controls from Newfoundland to Oxforshire Take-Off, Flight and Landing are fully Automatic. New York Times 19XX

11. Flight Control The Wright Brothers 1903 Sperry’s Autopilot 1912 Robert E. Lee 1947 V1 and V2 (A4) 1942 Sputnik 1957 Apollo 1969 Mars Pathfinder 1997

12. Telecommunications The Repeater Problem Black’s Invention 1928 “Singing” = Instability Nyquist’s Theorem 1932 Bode’s Paper 1940 Bode: Network Analysis and Feedback Amplifier Design

13. The Feedback Amplifier Telephone Calls Over Long Distances The Problem: How to Increase Signal Strength? The Solution: The Feedback Amplifier Patented by Black 1928Patent Granted 1937 Strong Development of Theory and Design Methods

14. Mervin Kelley on Black 1957 It is no exageration to say that without Black’s invention of the feedback amplifier, the present long-distance telephone and television networks, which covers our entire country and the transoceanic telephone cables would not exist.

15. The Magic of Feedback • Make a system behave as desired • Keep variables constant • Stabilize unstable system • Reduce effects of disturbancesand component variations • New freedom for designers

16. The Scene of 1940 Widespread use of automatic control in many fields • Power generation and distribution • Process control • Autopilots for ships and aircrafts • Telecommunications It was not realized that the problems were the same

17. A Discipline Emerges Principles Theory Design Methodology Applications Industrial Process Control Telecommunications Flight Control Mathematics

18. The Black Box Concept Output Input Abstraction Information hiding Transfer functions

19. Servomechanism Theory • Foundations • Complex variables • Laplace Transforms • Methodology Design • Frequency Response • Graphical Methods • System Concepts • Feedback • Feedforward • Analog Simulation • Implementation

20. Theory of Servomechanisms Hubert M. James Professor of Physics Purdue University Nathaniel B. Nichols Director of Research Taylor Instrument Companies Ralph S. Phillips Associate Professor of Mathematics University of Southern California Office of Scientific Research and Development National Defence Research Committee

21. Consequences Education Application Industrialization Organisation Journals Conferences

22. The Second Wave Driving Forces Applications Mathematics Computers A New Paradigm State Space Rapid Expansion Subspecialities Optimal Control Nonlinear Control Computer Control Stochastic Control Robust Control System Identification Adaptive Control CACE

23. Optimal Control Euler Lagrange Pontryagin Hamilton Jacobi Bellman 1707–1783 1736–1813 1962 1805–1865 1804–1851 1957 SII STAGE Five J-2 Engines 2, 500, 000N Thrust ATTITUDE AND THRUST CONTROL € Swivel Outer Four Engines GUIDANCE – SATURN € Optimum to Desired End Conditions NAVIGATION € Inertial Updating of Position and Velocity

24. CSL 1957 The Control Systems Laboratory 1959 Interdisciplinary, interdepartmental graduate research center 1967 New building, physics, control communication, computer engineering 1992 This building, 80 faculty, 7 departments, 320 grad students

25. 1. Introduction 2. A Brief History 3. State of the Art 4. The Future 5. Conclusions

26. Current Status A well established body of ideas, concepts, theory and design methods. Wide and growing application areas Still developing rapidly

27. Perhaps Most Important A good group of very talented and creative young researchers.

28. System Theory A large body of results with connections to many branches of mathematics Compactification badly needed! • Linear • Nonlinear • Stochastic • Discrete • Sampled • Distributed • Discrete Event • Hybrid

29. Design Methodology Modeling and Identification Design Simulation Implementation Computer Aided Control Engineering

30. Applications Energy generation Energy transmission Process control Discrete manufacturing Communication Transportation Buildings Entertainment Instrumentation Mechatronics Materials Physics Biology Economics

37. CD Player Tracking Searching Focusing DC-motor radial arm photo diodes Optical Pick-up Unit

38. Physics • Particle Accelerators • The 1984 Nobel Prize Van Der Meer • Repetetive Control Takano • Adaptive Optics • Atomic Force Microscope • Quantum and Molecular Systems

39. Economics • Complex Dynamical Systems With Much Manual Feedback and Complicated Criteria • H. Simon 1956: Certainty Equivalence • Program Trading – Relay Feedback • Merton-scholes – Stochastic Control • Wall Street and the City • The Financial Crisis

40. Biology Feedback is a central feature of life. The process of feedback governs how we grow, respond to stress and challenge, and regulate factors such as body temperature, blood pressure, and cholesterol level. It also makes it possible for us to stand upright. The mechanisms operate at every level, from the interaction of proteins in cells to the interaction of organisms in complex ecologies.

41. Charles Darwin It is not the strongest of the species that survive, nor the most intelligent, it is the one that is most adaptable to change.

42. A Dilemma Automatic control is a collection of ideas, concepts and theories with very wide applications areas. How to cope with: • Coupling to hardware • Coupling to industries • Process knowledge • Academic positioning

43. A Soul but No Body • Technology transfer • Student attraction • No home court • No base industry • Generality • Academic positioning

44. 1. Introduction 2. A Brief History 3. State of the Art 4. The Future 5. Conclusions

45. Natural and Engineering Sciences Understand Nature vs Man-made Systems Design and Operation of Systems Physical Laws vs System Principles Equally Challenging Useful for Mankind Theoretical Physics vs System Theory Use of Mathematics

46. A Perspective Modeling Real World Automatic Control Processes System Theory Systems Control Design Implementation Commissioning Operation

47. Stability and Controllability • Wright Brothers rejected the dogma that aircraft should be inherently stable • Minorsky 1922: It is an old adage that a stable ship is difficult to steer • Integrated process and control design • The cardinal sin of control

48. Co-Design of Process and Control

49. The Mercedes A-class Automatic control gives extra freedom to the designer ESP Unstable behavior improved by Electronic Stabilization Program (ESP)

50. Educational Challenges • Theory and applications expanding • How to compactify the knowledge? • The engineering aspect • The field had changed a lot • The introductory courses have not • Is it time for CSL to take an initiative?