This page contains information about errata for Feedback Systems. The errata listed here include known and corrected errors since the first printing of the book. Typos and other relatively minor corrections are omitted.
Conventions:
 Each line of text and each line of a displayed equation are counted as a line. Negative line numbers mean number of lines from the bottom of the page. First line on page = 1, last line on page = 1.
 Entries in boldface indicate errors which might change the interpretation of the text.
 The version refers to the release number in which the error was found. Errors are corrected in all subsequent releases of the text.
Page

Line

Erratum

Version

19

11

The Wright brothers made their first successful flight in 1903, not 1905

N/A

62

6

In Exercises 2.5 and 5.9, the (2,1) entry of the dynamics matrix should be abb

N/A

63

8

In Exercise 2.7, reference to inverted pendulum may be confusing

N/A

80

5

In Equation (3.19), the second term in the window dynamics should contain \rho c

N/A

91

6

In Exercise 3.2: use observable form, delta is the steering angle and "title" should be "tilt"

N/A

92

9

State space dynamics in Exercise 3.5 are not correct

N/A

106

7

Solution for x_2j in block diagonal form discussion has sign errors

N/A

107

1223

Closed loop dynamics matrix is incorrect in Example 4.6

N/A

108

8

Missing γ in equation (4.9)

N/A

110

11, 13

In Example 4.8, the linearized dynamics should contain 3 r_e, not 2 r_e

N/A

112

1

In Example 4.9, V(x) should be V(z)

N/A

117

3

Typo in the caption for Figure 4.15

N/A

126

5

In Exercise 4.1, x_0 should not be subtracted from timeshifted solution

N/A

126

5

In Exercise 4.1, tau should be defined as tt_0

N/A

127

5

In Exercise 4.2, a_e should be a

N/A

127

15

Sign error in second Lyapunov function in Exercise 4.4

N/A

128

3

In Exercise 4.6, Pm/J should be taken as 1 and factor of 1/2 is misplaced

N/A

129

2

In Exercise 4.14c, the transformation T and its inverse are swapped

N/A

131

15

Extraneous text "!linear" in Section 5.1

N/A

135

12

In equation (5.5), the upper limit of the integral should be t

N/A

144

7

Example 5.5 includes a damping term not shown in Figure 5.4

N/A

145

5

In Examples 5.5 and 5.6, dynamics in modal form should use z, not x

N/A

149

8

In Examples 5.5 and 5.6, dynamics in modal form should use z, not x

N/A

156

10

In AFM dynamics, c and k are missing subscript 2

N/A

164

11

Parameter values are missing in Exercise 5.3

N/A

164

3

Remove part (a) in Exercise 5.6

N/A

165

11

In Exercise 5.7, the 5% settling time should be 3 tau instead of 2 tau

N/A

165

16

In Exercise 5.8, the initial condition is x_0

N/A

166

3

In Exercises 2.5 and 5.9, the (2,1) entry of the dynamics matrix should be abb

N/A

169

12

In heuristic derivation of reachability test, α is missing subscript

N/A

180

2

Formula for k_r in equation (6.21) of Theorem 6.3 is incorrect

N/A

181

9

Missing 's' in expression for characteristic polynomial in discussion of eigenvalue assignment

N/A

184

10

In equation (6.24), the sign of the sin(omega t) term is incorrect for zeta less than one

N/A

188

2

Dynamics matrix in Example 6.7 has errors in (3,4) and (4,4) entries

N/A

198

14

In Exercise 6.4, need to assume A is invertible and C A^1 B is nonzero

N/A

200

9

In Exercise 6.13, R should be removed and rho should be rho_1

N/A

220

12

In computation of error dynamics, u_ff argument is missing

N/A

224

7

References to first and second equations are switched in computer implementation discussion

N/A

240

16, 13

Sign error in equation (8.17)  (sI  A) should be (A  sI)

N/A

240

11

Explanation of the lack of zeros when B or C is full rank is confusing

N/A

241

4, 6

In Example 8.5, q should be replaced by theta

N/A

249

3

Location of the process pole is missing a zero in figure caption for cruise control example

N/A

256

1

Caption for Figure 8.15b is missing an s in the numerator

N/A

277

13

In Theorem 9.3, N should be Z

N/A

288

3

Exponential signal is incorrect on the lefthand side of harmonic expansion equation

N/A

292

18

In Exercise 9.9, 10/a should be 1/tau

N/A

307

9

Toward end of Section 10.4, k_i should be k_t

N/A

311

3

Missing ydot after equation (10.16)

N/A

314

5

Dynamics for x_2 should test for e less than e_0, not e less than 1

N/A

315

8

Extraneous 'LDH' and comment in the text

N/A

319

0

Arrow labeled u_fd in Figure 11.3 is in the wrong direction

N/A

319

7

Extraneous text "!design" in Chapter 12

N/A

323

9

Maximum sensitivity occurs at frequency omega_ms not omega_sc

N/A

336

8

Extraneous text "!design" in Chapter 12

N/A

345

12

Exercise 11.4 should be Example 11.4 in Exercise 11.9

N/A

345

14

T_d should be T_f in Exercise 11.9

N/A

345

5

Numerator and denominator are switched in Exercise 11.11

N/A

356

6, 12

In Example 12.6, n = 1 should be n = 1

N/A

369

1

Extraneous text "!design" in Chapter 12

N/A
