This book will sell because relay feedback is of interest both to the academic community as being a fundamental tool in the advancement of control systems based on real data and to practising engineers to whom it offers methods of maintaining plant and processes within set limits of performance.
From the reviews:
“Relay Feedback: Analysis, Identification and Control is an extensive text covering the analysis of oscillations in relay feedback systems, system identification based on relay feedback experiments, and controller design based on the identified models. ... This book is suitable for both researchers and workers interested in obtaining an in-depth understanding of relay feedback systems and their application to automatic tuning of controllers. ... The book appeals to a diverse audience, from researchers in nonlinear control to practicing control engineers.” (Karl H. Johansson, IEEE Control Systems Magazine, Vol. 27, June, 2007)