# Version 2.10d

This page contains information about version 2.10d of *Feedback Systems* by Karl J. Åström and Richard M. Murray. Version 2.10d contains corrections to the first printing through 19 July 2011. This revision contains corrections to the third printing of the book.

Additional info and links:

- Revision date: 19 July 2011
- Complete book - this a PDF of the entire book, as a single PDF file (408 pages, 8 MB).
- Individual chapters: P, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, B
- Hyperlink version - this is a PDF of the entire book, with hypertext links on references for equations, figures, citations, etc.
*Note: the page numbers in this version are different from the print version.* - iPad optimized version - see the e-book page for information on how to use this file.

The electronic edition of *Feedback Systems* is provided with the permission of the publisher, Princeton University Press. This manuscript is for personal use only and may not be reproduced, in whole or in part, without written consent from the publisher.

## Errata

A full list of errata including page and line numbers is maintained on the errata page. The following errata have been identified in this version of the text (for a listing in page order, see version 2.10d errata):

- Errata: At the end of Example 4.6, the roots should have negative real part instead of being positive
- Errata: In Example 4.11, Lyapunov equation entries for f' 1 and f' 2 are switched (solution is correct)
- Errata: Near end of Example 4.11, denominator of f'(z 2e) term should be squared
- Errata: In Exercise 4.2, the q in term should be positive
- Errata: In Example 5.3, dot missing from q in middle term of displayed equation for dynamics with damping
- Errata: At end of Example 5.5, eigenvalue approximations are incorrect
- Errata: In Example 5.12, expression non-equilibrium condition has wrong symbols
- Errata: In equation (6.17), elements of the output matrix should be in the opposite order
- Errata: In Example 6.5, reference variable should be L d instead of r
- Errata: For underdamped second order system, eigenvalues are listed incorrectly
- Errata: In Example 6.7, the imaginary part of the first pair of eigenvalues is missing factor of i
- Errata: In Example 6.8, the state error should be \xi and the input should be F
- Errata: In equation (8.6), matrix inverse is computed incorrectly
- Errata: In Example 8.5, leading term in denominator for H \theta F should be cubic in s
- Errata: In Example 8.6, numerator gain term for G ur should be k r instead of k 1
- Errata: Last equation in Example 8.6 has errors in numerator expressions
- Errata: In Example 9.9, 'gain margin' g m should be 'stability margin' s m
- Errata: The expressions for the PID parameters for the op amp implementation are incorrect
- Errata: In equation (12.13) and the displayed equation above it, T should be -T
- Errata: In equation (12.16), a is not defined and a factor of a is missing in numerator the last term
- Errata: In Example 2.5, expression for the step response is missing some factors
- Errata: In Example 2.7, q should be replaced by p (three places) and theta (one place)

Note that errata in later versions of the text may also apply to this version. A full list of errata in all versions of the text is maintained on the errata page.