Sampled-Data Control Systems

The first German edition of this book appeared in 1972, and in Polish translation in 1976. It covered the analysis and synthesis of sampled-data systems. The second German edition of 1983 ex tended the scope to design, in particular design for robustness of control system properties with respect to uncertainty of plant parameters. This book is a revised translation of the second Ger man edition. The revisions concern primarily a new treatment of the finite effect sequences and the use of nice numerical proper ties of Hessenberg forms. The introduction describes examples of sampled-data systems, in particular digital controllers, and analyzes the sampler and hold; also some design aspects are introduced. Chapter 2 reviews the modelling and analysis of continuous systems. Pole shifting is formulated as an affine mapping, here some n~w material on fixing some eigenvalues or some gains in a design step is included. Chapter 3 treats the analysis of sampled-data systems by state space and z-transform methods. This includes sections on inter sampling behavior, time-delay systems, absolute stability and non synchronous sampling. Chapter 4 treats controllability and reach ability of discrete-time systems, controllability regions for con strained inputs and the choice of the sampling interval primarily under controllability aspects. Chapter 5 deals with observability and constructability both from the discrete and continuous plant output. Full and reduced order observers are treated as well as disturbance observers.

Autorentext

Jürgen Ackermann studied Control Engineering under the guidance of Prof. Oppelt in Darmstadt, and Control Theory under the guidance of Prof. Jury in Berkeley, California. He is well known for his contributions to the theory of control systems, as treated in his books on sampled-data [7] and robust control systems [10]. Perhaps his best known result is Ackermann s formula for pole placement [38]. J. Ackermann has a long association with DLR, the German Aerospace Center in Oberpfaffenhofen, Germany, where he was director of the Institute of Robotics and Mechatronics from 1974 to his retirement in 2001. He has attracted to the institute and supported such well known members of the international control and dynamics community as G. Hirzinger, W. Kortüm, G. Grübel, R. Schwertassek, K. Well (now Stuttgart) and G. Kreisselmeier (now Kassel). Together with them he has initiated and guided many applied research projects which include robust autopilots and jet engine control systems for aircraft; trajectory optimization of aircraft, missiles and spacecraft; control of large flexible structures; robotics for space and manufacturing application, modelling and control of trains, maglev vehicles and automobiles. He has developed a general theory of robust control for steering of vehicles. It is based on robust triangular decoupling of steering of a point mass along a desired trajectory and automatic control of undesired vehicle rotations. J. Ackermann holds six patents for robust feedback control strategies to increase the safety of car driving [1-6]. He initiated an experimental program with BMW, which has shown spectacular safety advantages in road tests with side-wind and mu-split braking [110]. The concept was transferred to flight control [146] where it resulted in a remarkable weight reduction. In both cases the advantages resulted from the fact, that an automatic control system can compensate strong disturbance torques faster than the driver orpilot. J. Ackermann was a Member of the IFAC Council (1990-1996), where he initiated the creation of a new Technical Committee on Automotive Control. He is a founding member of the European Union Control Association and was a member of the IEEE-CSS Board of Governors (1993-1995) and of the "Beirat" of GMR (the German IFAC-NMO). He served on the Editorial Boards of Automatica, IEEE Transactions on Automatic Control (as Associate Editor at Large), C-TAT, Robust and Nonlinear Control, Automatisierungstechnik and was Guest Editor for special issues on "Robust Control" and "Automotive Control". He was chairman of the IPC for the 1989 IEEE International Conference on Control and Applications (Jerusalem), and chaired an IEEE Award Committee, the IFAC Nichols medal committee and the Theory Committee of GMR. He was also a Member of the Senate of the DLR (1986-1998) and of the Advisory Board of the "Deutsches Museum" in Munich (1986-1998). From 1988 to 1995 he was elected chief reviewer for Control Engineering for the Deutsche Forschungsgemeinschaft. Presently he is chairman of the IFAC awards committee for the Nichols medal. J. Ackermann received the J. M. Boykow-Award (1970), the VDE Best Publication Award (1973), he is an Otto-Lilienthal-Fellow (1989) and an IEEE-Fellow (1992), he is recipient of the first Nichols medal of IFAC "for robust control design methods and their use to improve automobile safety" (1996). Also in 1996 he received the Bode Prize of IEEE. In 2005 he was appointed IFAC Fellow "for outstanding and extraordinary contributions to the field of automatic control and involvement in IFAC activities in the promotion of the field". He is adjunct professor at the Technical University Munich and has held visiting appointments at Urbana-Champaign, Canberra, Irvine, Berkeley and Stanford. He was invited for numerous plenary keynote lectures at international conferences [11-26].

Inhalt

1. Introduction.- 1.1 Sampling, Sampled-Data Controllers.- 1.2 Sampled-Data Systems.- 1.3 Design Problems for Sampled-Data Loops.- 1.4 Exercises.- 2. Continuous Systems.- 2.1 Modelling, Linearization.- 2.2 Basis of the State Space.- 2.3 System Properties.- 2.4 Solutions of the Differential Equation.- 2.5 Specifications.- 2.6 Pole Shifting.- 2.7 Exercises.- 3. Modelling and Analysis of Sampled-Data Systems.- 3.1 Discretization of the Plant.- 3.2 Homogeneous Solutions: Eigenvalues, Solution Sequences.- 3.3 Inhomogeneous Solutions: z-Transfer Function, Impulse and Step Responses.- 3.4 Discrete Controller and Control Loop.- 3.5 Root Locus Plots and Pole Specifications in the z-Plane.- 3.6. Time Domain Solutions and Specifications.- 3.7 Behavior Between the Sampling Instants.- 3.8 Time-Delay Systems.- 3.9 Frequency Response Methods.- 3.10 Special Sampling Problems.- 3.11 Exercises.- 4. Controllability, Choice of Sampling Period and Pole Assignment.- 4.1 Controllability and Reachability.- 4.2 Controllability Regions for Constrained Inputs.- 4.3 Choice of the Sampling Interval.- 4.4 Pole Assignment.- 4.5 Exercises.- 5. Observability and Observers.- 5.1 Observability and Constructability.- 5.2 The Observer of Order n.- 5.3 The Reduced Order Observer.- 5.4 Choice of the Observer Poles.- 5.5 Disturbance Observer.- 5.6 Exercises.- 6. Control Loop Synthesis.- 6.1 Design Methodology.- 6.2 Controller Structures.- 6.3 Separation.- 6.4 Construction of a Linear Function of the States.- 6.5 Synthesis by Polynomial Equations.- 6.6 Pole-Zero-Cancellations.- 6.7 Closed-loop Transfer Function and Prefilter.- 6.8 Disturbance Compensation.- 6.9 Exercises.- 7. Geometric Stability Investigation and Pole Region Assignment.- 7.1 Stability.- 7.2 Stability Region in P Space.- 7.3 Barycentric Coordinates, Bilinear Transformation.- 7.4 ?-Stability.- 7.5 Pole-Region Assignment.- 7.6 Graphic Representation in Two-dimensional Cross Sections.- 7.7 Exercises.- 8. Design of Robust Control Systems.- 8.1 Robustness Problems.- 8.2 Structural Assumptions and Existence of Robust Controllers.- 8.3 Simultaneous Pole Region Assignment.- 8.4 Selection of a Controller from the Admissible Solution Set.- 8.5 Stabilization of the Short-period Longitudinal Mode of an F4-E with Canards.- 8.6 Design by Optimization of a Vector Performance Criterion.- 8.7 Exercises.- 9. Multivariable Systems.- 9.1 Controllability and Observability Structure.- 9.2 Finite Effect Sequences (FESs).- 9.3 FES Assignment.- 9.4 Quadratic Optimal Control.- 9.5 Exercises.- A…