What's new in the second edition?

S.Skogestad and I.Postlethwaite, Multivariable feedback control - Analysis and design, 2nd Edition, Wiley, 2005, 592 pages.

In the second edition, we have corrected a number of minor mistakes and made numerous changes and additions throughout the text, partly arising from the many questions and comments we have received from interested readers and partly to reflect developments in the field. The main additions and changes are:

• Chapter 2: Material has been included on unstable plants, the feedback amplifier, the lower gain margin, simple IMC tuning rules for PID control, and the half rule for estimating the effective delay.
• Chapter 3: Some material on the relative gain array has been moved in from Chapter 10.
• Chapter 4: Changes have been made to the tests of state controllability and observability (of course, they are equivalent to the old ones).
• Chapters 5 and 6: New results have been included on fundamental performance limitations introduced by RHP-poles and RHP-zeros.
• Chapter 6: The section on limitations imposed by uncertainty has been rewritten
• Chapter 7: The examples of parametric uncertainty have been introduced earlier and shortened.
• Chapter 9: A clear strategy is given for incorporating integral action into LQG control.
• Chapter 10: The chapter has been reorganized. New material has been included on the selection of controlled variables and self-optimizing control. The section on decentralized control has been rewritten and several examples have been added.
• Chapter 12: A complete new chapter on LMIs.
• Appendix: Minor changes to positive definite matrices and the all-pass factorization.

In reality, the book has been expanded by more than 100 pages, but this is not reflected in the number of pages in the second edition because the page size has also been increased. All the Matlab programs have been updated for compatibility with the new Robust Control toolbox.