Difference between revisions of "Modern Robotics Errata"

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[https://docs.google.com/forms/d/1iZ_3LsWR1iuPJmRsUQsa2ehZj6p-qKQfx8NRKaTlIuE/edit '''Please click here to report any corrections for the book. (Please make sure you are using the May 3, 2017, version of the book, or the hardcover book published by Cambridge University Press.)''']
[https://docs.google.com/forms/d/1iZ_3LsWR1iuPJmRsUQsa2ehZj6p-qKQfx8NRKaTlIuE/edit '''Please click here to report any corrections for the book, practice exercises, or linear algebra refresher appendix. (Please make sure you are using the May 3, 2017, online version of the book, or the hardcover book published by Cambridge University Press.)''']


Errata below are for the hardcover book published by Cambridge University Press and the preprint version of the book posted on May 3, 2017. Thanks to everyone who provided corrections to earlier versions!
Errata below are for [[Modern_Robotics|the hardcover book published by Cambridge University Press, the preprint version of the book posted on May 3, 2017, the practice exercises, and the linear algebra refresher appendix]]. Thanks to everyone who provided corrections to earlier versions!




== Significant corrections ==
== Book: Significant corrections ==


=== Chapter 3 ===
=== Chapter 3 ===


* In the caption of Figure 3.3, it should read <math>\hat{\text{x}}_{\text{b}} = (1/2, \sqrt{3}/2)</math> and <math>\hat{\text{y}}_{\text{b}} = (-\sqrt{3}/2, 1/2)</math>.
* There is a typo in the final matrix, <math>T_{ce}</math>. The term <math>130/\sqrt{2}</math> should be <math>160/\sqrt{2}</math>. (Also, there is no need to use <math>T_{ad}</math> in this example.)
* In the displayed equation just after Equation (3.76), the left-hand side should be <math>[\mathcal{V}_s]</math> (the brackets are missing).
* In the displayed equation just after Equation (3.76), the left-hand side should be <math>[\mathcal{V}_s]</math> (the brackets are missing).
* Exercise 3.16(i) asks for "the <math>\{q,\hat{s},h\}</math> representation" but it should say "a <math>\{q,\hat{s},h\}</math> representation" since <math>q</math> is not unique.

=== Chapter 4 ===

* Example 4.1, last row of the table (screw axis for joint 3): The linear component <math>v_i</math> should be <math>(0, -L_2, 0)</math> (the <math>-</math> sign is missing).


=== Chapter 5 ===
=== Chapter 5 ===


* Equation (5.7): The the first two terms on the right-hand side of the equation should be <math>J_{s1} \dot{\theta}_1 + J_{s2}(\theta) \dot{\theta}_2</math>.
* Equation (5.7): The the first two terms on the right-hand side of the equation should be <math>J_{s1} \dot{\theta}_1 + J_{s2}(\theta) \dot{\theta}_2</math>.

* Exercise 5.2(b): The wrench applied by the last link, expressed in the {s} frame, is 5 N in the <math>\hat{\text{y}}_{\text{s}}</math> direction, with zeros in all other components. (The wording seems to imply that the force is through the tip of the last link, which is incorrect.)


* Exercise 5.16 and Figure 5.26: The robot is referred to as PRRRRR, but it is PRPRRR.
* Exercise 5.16 and Figure 5.26: The robot is referred to as PRRRRR, but it is PRPRRR.
Line 21: Line 30:


=== Chapter 8 ===
=== Chapter 8 ===

* In Equation (8.14), <math>\mathcal{K}(\theta)</math> should be replaced by <math>\mathcal{K}(\theta,\dot{\theta})</math>.


* Figure 8.5 says the volume of the rectangular parallelepiped is <math>abc</math> but it should be <math>hlw</math>.
* Figure 8.5 says the volume of the rectangular parallelepiped is <math>abc</math> but it should be <math>hlw</math>.

* End of first sentence after Eq (8.26) in Section 8.2.1 should read "columns of <math>R_{bc}</math> correspond to the eigenvectors of <math>\mathcal{I}_b</math>." (The word "eigenvalues" should be replaced by "eigenvectors.")

* Caption of Figure 8.10: The operating region is light gray and the continuous operating region is dark gray.


* Exercise 8.6(a): The expression <math>\text{ad}_{J_i}(J_j)</math> has the indices switched; the correct expression is <math>\text{ad}_{J_j}(J_i)</math>.
* Exercise 8.6(a): The expression <math>\text{ad}_{J_i}(J_j)</math> has the indices switched; the correct expression is <math>\text{ad}_{J_j}(J_i)</math>.
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\mathcal{A}^{\rm T} \mathcal{L}^{\rm T} \mathcal{GL} [\mbox{ad}_{\mathcal{A} \dot{\theta}}] \mathcal{WLA}
\mathcal{A}^{\rm T} \mathcal{L}^{\rm T} \mathcal{GL} [\mbox{ad}_{\mathcal{A} \dot{\theta}}] \mathcal{WLA}
</math>
</math>

=== Chapter 10 ===

* Equation (10.4) should read <math> u = F(q) - B \dot{q}</math> (the plus sign in the book should be a minus sign).


=== Chapter 11 ===
=== Chapter 11 ===


* In the displayed equation after Equation (11.18), the vector <math>X_e(t)</math> is a six-vector. The bottom three elements are written correctly, but the top three elements, an angular velocity, are written instead in their 3x3 <math>so(3)</math> form.
* In the displayed equation after Equation (11.18), the vector <math>X_e(t)</math> is a six-vector. The bottom three elements are written correctly, but the top three elements, an angular velocity, are written instead in their 3x3 <math>so(3)</math> form. Also, the term written <math>R^{\text{T}}(d)</math> should be written <math>R^{\text{T}}(t)</math>.


* In Equation (11.33), the right-hand side should be zero (<math>c = 0</math>).
* Figure 11.24, the Robonaut 2 series elastic actuator, 4th sentence of the caption: The words "outer" and "inner" should be switched to read "The inner ring of hole mounts connects to the harmonic gearhead output, and the outer ring of hole mounts is the output of the SEA, connecting to the next link."


* Figure 11.24, the Robonaut 2 series elastic actuator, 4th sentence of the caption: The words "outer" and "inner" should be switched, so the new sentence reads "The inner ring of hole mounts connects to the harmonic gearhead output, and the outer ring of hole mounts is the output of the SEA, connecting to the next link."
== Minor typos, etc., no danger of misunderstanding ==

=== Chapter 12 ===

* In Example 12.4, the elements of the wrenches <math>\mathcal{F}_1, \mathcal{F}_2, \mathcal{F}_3</math> are erroneously written in the order <math>(f_x,f_y,m_z)</math>; they should be written in the order <math>(m_z,f_x,f_y)</math>, i.e., <math>(-2,0,1), (1,-1,0), (1,1,0)</math>, respectively.

=== Appendix C ===

* Section C.3, Equation (C.5): All instances of <math>\phi_{i-1}</math> should be replaced by <math>\phi_i</math>.

* In Equation (C.12), two instances of <math>M_{i-1}</math> should be replaced by <math>M_i</math>.

== Book: Minor typos, etc., no danger of misunderstanding ==


=== Chapter 1 ===
=== Chapter 1 ===
Line 47: Line 78:


* Chapter 2.2.2, Example 2.3: "Substituting" is misspelled.
* Chapter 2.2.2, Example 2.3: "Substituting" is misspelled.

=== Chapter 5 ===

* Figure 5.15(b): The circular arrow indicating the rotation of joint 3 is slightly misplaced.

* Exercise 5.25: This problem instructs you to use the space Jacobian, so you should use it for the manipulability ellipsoids in this problem (even though it is generally preferred to use the body Jacobian for manipulability ellipsoids).


=== Chapter 6 ===
=== Chapter 6 ===
Line 54: Line 91:
=== Chapter 7 ===
=== Chapter 7 ===


* (online version only) Last line of first paragraph of Chapter 7.1: "valuees" should be "values."
* Just below caption for Figure 7.8: There is an extraneous dot.
* Just below caption for Figure 7.8: There is an extraneous dot.


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* (online version only) Chapter 8.1.1, last paragraph: <math>\dot{\theta}_1</math> is improperly typeset.
* (online version only) Chapter 8.1.1, last paragraph: <math>\dot{\theta}_1</math> is improperly typeset.

=== Chapter 12 ===

* Caption of Figure 12.14, second-to-last sentence: "rotation if possible" should be "rotation is possible."


== A partial list of errata contributors ==
== A partial list of errata contributors ==
Line 64: Line 106:
Thanks to the following people who provided corrections, starting from the preliminary version of the book posted in October, 2016:
Thanks to the following people who provided corrections, starting from the preliminary version of the book posted in October, 2016:


H. Andy Nam, Eric Lee, Yuchen Rao, Chainatee Tanakulrongson, Mengjiao Hong, Kevin Cheng, Jens Lundell, Elton Cheng, Michael Young, Jarvis Schultz, Logan Springgate, Sofya Akhmametyeva, Aykut Onol, Josh Holcomb, Yue Chen, Mark Shi, AJ Ibraheem, Yalun Wen, Seongjae Jeong, Josh Mehling, Drew Warren
H. Andy Nam, Eric Lee, Yuchen Rao, Chainatee Tanakulrongson, Mengjiao Hong, Kevin Cheng, Jens Lundell, Elton Cheng, Michael Young, Jarvis Schultz, Logan Springgate, Sofya Akhmametyeva, Aykut Onol, Josh Holcomb, Yue Chen, Mark Shi, AJ Ibraheem, Yalun Wen, Seongjae Jeong, Josh Mehling, Felix Wang, Drew Warren, Chris Miller, Clemens Eppner, Zack Woodruff, Jian Shi, Jixiang Zhang, Shachar Liberman, Will Wu, Dirk Boysen, Awe Wang, Ville Kyrki


<!--
<!--
Other updates and corrections can be found in the google drive folder.

Other minor things, not worth mentioning:
Other minor things, not worth mentioning:

Could give an operation to convert so(3) and se(3) to their vector reps, e.g., ]log T_{ab}[ or vec(log T_{ab}) .

In figs showing blocks sliding in channels in chapter 2 (e.g., exercises), some show arrows to show the sliding motion possibility, others do not. Could be confusing, i.e., if arrows are missing maybe motion isn't possible.


Eq (5.4): transpose should be roman, not italic
Eq (5.4): transpose should be roman, not italic

After Eq (5.26), in text, transpose should be roman


near end of chap 7.2.1: the inverse transpose should be roman
near end of chap 7.2.1: the inverse transpose should be roman
Line 80: Line 130:


Chapter 8.6: several instances of inverse transpose being italic, not roman.
Chapter 8.6: several instances of inverse transpose being italic, not roman.

A few paragraphs after eq (13.31), it says the absolute value of v_d should not be zero. Should just say that v_d should not be zero.
-->
-->

Revision as of 21:42, 11 February 2019

Please click here to report any corrections for the book, practice exercises, or linear algebra refresher appendix. (Please make sure you are using the May 3, 2017, online version of the book, or the hardcover book published by Cambridge University Press.)

Errata below are for the hardcover book published by Cambridge University Press, the preprint version of the book posted on May 3, 2017, the practice exercises, and the linear algebra refresher appendix. Thanks to everyone who provided corrections to earlier versions!


Book: Significant corrections

Chapter 3

  • In the caption of Figure 3.3, it should read and .
  • There is a typo in the final matrix, . The term should be . (Also, there is no need to use in this example.)
  • In the displayed equation just after Equation (3.76), the left-hand side should be (the brackets are missing).
  • Exercise 3.16(i) asks for "the representation" but it should say "a representation" since is not unique.

Chapter 4

  • Example 4.1, last row of the table (screw axis for joint 3): The linear component should be (the sign is missing).

Chapter 5

  • Equation (5.7): The the first two terms on the right-hand side of the equation should be .
  • Exercise 5.2(b): The wrench applied by the last link, expressed in the {s} frame, is 5 N in the direction, with zeros in all other components. (The wording seems to imply that the force is through the tip of the last link, which is incorrect.)
  • Exercise 5.16 and Figure 5.26: The robot is referred to as PRRRRR, but it is PRPRRR.

Chapter 6

  • Chapter 6.3, first line after Eq (6.7): the matrices and are referred to as twists, but these are the se(3) matrix representations of the twists.

Chapter 8

  • In Equation (8.14), should be replaced by .
  • Figure 8.5 says the volume of the rectangular parallelepiped is but it should be .
  • End of first sentence after Eq (8.26) in Section 8.2.1 should read "columns of correspond to the eigenvectors of ." (The word "eigenvalues" should be replaced by "eigenvectors.")
  • Caption of Figure 8.10: The operating region is light gray and the continuous operating region is dark gray.
  • Exercise 8.6(a): The expression has the indices switched; the correct expression is .
  • Exercise 8.7: The expression should be written:

Chapter 10

  • Equation (10.4) should read (the plus sign in the book should be a minus sign).

Chapter 11

  • In the displayed equation after Equation (11.18), the vector is a six-vector. The bottom three elements are written correctly, but the top three elements, an angular velocity, are written instead in their 3x3 form. Also, the term written should be written .
  • In Equation (11.33), the right-hand side should be zero ().
  • Figure 11.24, the Robonaut 2 series elastic actuator, 4th sentence of the caption: The words "outer" and "inner" should be switched, so the new sentence reads "The inner ring of hole mounts connects to the harmonic gearhead output, and the outer ring of hole mounts is the output of the SEA, connecting to the next link."

Chapter 12

  • In Example 12.4, the elements of the wrenches are erroneously written in the order ; they should be written in the order , i.e., , respectively.

Appendix C

  • Section C.3, Equation (C.5): All instances of should be replaced by .
  • In Equation (C.12), two instances of should be replaced by .

Book: Minor typos, etc., no danger of misunderstanding

Chapter 1

  • (online version only) Description of Chapter 6: "jont positions" should be "joint positions."

Chapter 2

  • Chapter 2.2.2, Example 2.3: "Substituting" is misspelled.

Chapter 5

  • Figure 5.15(b): The circular arrow indicating the rotation of joint 3 is slightly misplaced.
  • Exercise 5.25: This problem instructs you to use the space Jacobian, so you should use it for the manipulability ellipsoids in this problem (even though it is generally preferred to use the body Jacobian for manipulability ellipsoids).

Chapter 6

  • (online version only) Figure 6.7: should be (five times) and should be (one time).

Chapter 7

  • (online version only) Last line of first paragraph of Chapter 7.1: "valuees" should be "values."
  • Just below caption for Figure 7.8: There is an extraneous dot.

Chapter 8

  • (online version only) Chapter 8.1.1, last paragraph: is improperly typeset.

Chapter 12

  • Caption of Figure 12.14, second-to-last sentence: "rotation if possible" should be "rotation is possible."

A partial list of errata contributors

Thanks to the following people who provided corrections, starting from the preliminary version of the book posted in October, 2016:

H. Andy Nam, Eric Lee, Yuchen Rao, Chainatee Tanakulrongson, Mengjiao Hong, Kevin Cheng, Jens Lundell, Elton Cheng, Michael Young, Jarvis Schultz, Logan Springgate, Sofya Akhmametyeva, Aykut Onol, Josh Holcomb, Yue Chen, Mark Shi, AJ Ibraheem, Yalun Wen, Seongjae Jeong, Josh Mehling, Felix Wang, Drew Warren, Chris Miller, Clemens Eppner, Zack Woodruff, Jian Shi, Jixiang Zhang, Shachar Liberman, Will Wu, Dirk Boysen, Awe Wang, Ville Kyrki