Introduction

The motivating introduction recalls major objectives of control systems, i.e. to stabilise the dynamic behaviour of a system subject to external disturbances, to ensure that prescribed performance requirements are met and to minimise or maximise defined objective functions. Moreover, stability and performance shall be robust with regard to model inaccuracies and uncertainties. The introduction stresses that the accuracy, the complexity and appropriateness of system models and thus the design of a controller depend on a number of facts and decisions. Due to the complexity of today’s engineering systems to be controlled, the textbook focuses on multivariable control but confines on linear time invariant (LTI) models to keep the book manageable. The presentation ranges from the discussion of the approximation of multivariable systems with multiple internal interactions by multi-loop systems to the more modern formulation of control problems as linear matrix inequalities (LMIs). The chapter outlines the organisation of the book, explains and motivates the subjects of the following chapters which build up on each other in structured way and concludes with a brief introduction of some used notations.