Modern Robotics Errata - Revision history

Lynch: /* Chapter 4 */

2024-06-25T07:27:38Z

Chapter 4

← Older revision		Revision as of 02:27, 25 June 2024
Line 15:		Line 15:
	=== Chapter 4 ===		=== Chapter 4 ===

	* Exercise 4.21: The question should begin "For each <math>T</math> below..." instead of "For each <math>T \in SE(3)</math> below...". (Since the first part of the problem is determining whether <math>T</math> is indeed an element of <math>SE(3)</math>.		* Exercise 4.21: The question should begin "For each <math>T</math> below..." instead of "For each <math>T \in SE(3)</math> below...". (Since the first part of the problem is determining whether <math>T</math> is indeed an element of <math>SE(3)</math>.)

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

Lynch: /* Throughout the book */

2022-02-03T14:04:08Z

Throughout the book

← Older revision		Revision as of 09:04, 3 February 2022
Line 37:		Line 37:
	=== Throughout the book ===		=== Throughout the book ===

	* The V-REP simulator has been discontinued and replaced by the [https://www.coppeliarobotics.com/ CoppeliaSim] simulator. This does not change anything in the book (or the simulation scenes provided to accompany the book). Replace every instance of "V-REP" with "CoppeliaSim."		* The V-REP simulator has been discontinued and replaced by the [https://www.coppeliarobotics.com/ CoppeliaSim] simulator. This does not change anything in the book (or the simulation scenes provided to accompany the book). Replace every instance of "V-REP" with "CoppeliaSim." There is one reference to V-REP in the Preface and one in Figure 1.1; those may be the only uses.

	=== Chapter 2 ===		=== Chapter 2 ===

Lynch at 13:58, 3 February 2022

2022-02-03T13:58:30Z

← Older revision		Revision as of 08:58, 3 February 2022
Line 30:		Line 30:
	=== Chapter 11 ===		=== Chapter 11 ===

	* The one-sentence paragraph near the beginning of Chapter 11.3.3, after Equation (11.16): Change "As in Section 11.3.2 ... where <math>k_p, k_i > 0</math>." ~~should be changed~~ to "The diagonal entries of the diagonal gain matrices <math>K_p, K_i \in \mathbb{R}^{6 \times 6}</math> should be positive." (Currently it says that these matrices shold have the form <math>k_p I</math> and <math>k_i I</math>, but the units for a twist are different (first three units are angular velocities, last three units are linear velocities). So you may wish to use one positive value for the top three elements on the diagonal and a different positive value for the bottom three elements on the diagonal.)		* The one-sentence paragraph near the beginning of Chapter 11.3.3, after Equation (11.16): Change "As in Section 11.3.2 ... where <math>k_p, k_i > 0</math>." to "The diagonal entries of the diagonal gain matrices <math>K_p, K_i \in \mathbb{R}^{6 \times 6}</math> should be positive." (Currently it says that these matrices shold have the form <math>k_p I</math> and <math>k_i I</math>, but the units for a twist are different [first three units are angular velocities, last three units are linear velocities]. So you may wish to use one positive value for the top three elements on the diagonal and a different positive value for the bottom three elements on the diagonal.)
	* Chapter 11.5, Equations (11.52) and (11.53) (and nearby text): The term <math>K_{fp}</math> in Equations (11.52) and (11.53) should be <math>(K_{fp}+I)</math>. (<math>I</math> is the identity matrix.) In the text immediately after Equation (11.51), the term "positive-definite" should be eliminated. In the text immediately after Equation (11.53), <math>K_{fp}</math> should be replaced by <math>(K_{fp}+I)</math>.		* Chapter 11.5, Equations (11.52) and (11.53) (and nearby text): The term <math>K_{fp}</math> in Equations (11.52) and (11.53) should be <math>(K_{fp}+I)</math>. (<math>I</math> is the identity matrix.) In the text immediately after Equation (11.51), the term "positive-definite" should be eliminated. In the text immediately after Equation (11.53), <math>K_{fp}</math> should be replaced by <math>(K_{fp}+I)</math>.

Lynch: /* A partial list of errata contributors */

2022-02-03T13:52:53Z

A partial list of errata contributors

← Older revision		Revision as of 08:52, 3 February 2022
Line 78:		Line 78:
	[w1×w2] = [w1][w2] - [w2][w1]		[w1×w2] = [w1][w2] - [w2][w1]
	for use in the derivation of Eq (8.23) between lines 3 and 4.		for use in the derivation of Eq (8.23) between lines 3 and 4.

⚫	-->

	[[Modern Robotics Print-Only Errata\|Temporary Print-Only Errata]]		[[Modern Robotics Print-Only Errata\|Temporary Print-Only Errata]]

		⚫	-->

Lynch at 13:52, 3 February 2022

2022-02-03T13:52:31Z

← Older revision		Revision as of 08:52, 3 February 2022
Line 80:		Line 80:

	-->		-->

			[[Modern Robotics Print-Only Errata\|Temporary Print-Only Errata]]

Lynch at 13:50, 3 February 2022

2022-02-03T13:50:38Z

← Older revision		Revision as of 08:50, 3 February 2022
Line 37:		Line 37:
	=== Throughout the book ===		=== Throughout the book ===

	* The V-REP simulator has been discontinued and replaced by the [https://www.coppeliarobotics.com/ CoppeliaSim] simulator. This does not change anything in the book (or the simulation scenes provided to accompany the book).		* The V-REP simulator has been discontinued and replaced by the [https://www.coppeliarobotics.com/ CoppeliaSim] simulator. This does not change anything in the book (or the simulation scenes provided to accompany the book). Replace every instance of "V-REP" with "CoppeliaSim."

	=== Chapter 2 ===		=== Chapter 2 ===

	* Figure 2.9 (left): bold segment of the line should not extend beyond the closing parenthesis at b.		* Figure 2.9 (left): the bold segment of the line should not extend beyond the closing parenthesis at b.

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

Lynch at 13:45, 3 February 2022

2022-02-03T13:45:26Z

← Older revision		Revision as of 08:45, 3 February 2022
Line 31:		Line 31:

	* The one-sentence paragraph near the beginning of Chapter 11.3.3, after Equation (11.16): Change "As in Section 11.3.2 ... where <math>k_p, k_i > 0</math>." should be changed to "The diagonal entries of the diagonal gain matrices <math>K_p, K_i \in \mathbb{R}^{6 \times 6}</math> should be positive." (Currently it says that these matrices shold have the form <math>k_p I</math> and <math>k_i I</math>, but the units for a twist are different (first three units are angular velocities, last three units are linear velocities). So you may wish to use one positive value for the top three elements on the diagonal and a different positive value for the bottom three elements on the diagonal.)		* The one-sentence paragraph near the beginning of Chapter 11.3.3, after Equation (11.16): Change "As in Section 11.3.2 ... where <math>k_p, k_i > 0</math>." should be changed to "The diagonal entries of the diagonal gain matrices <math>K_p, K_i \in \mathbb{R}^{6 \times 6}</math> should be positive." (Currently it says that these matrices shold have the form <math>k_p I</math> and <math>k_i I</math>, but the units for a twist are different (first three units are angular velocities, last three units are linear velocities). So you may wish to use one positive value for the top three elements on the diagonal and a different positive value for the bottom three elements on the diagonal.)
	* Chapter 11.5, Equations (11.52) and (11.53) (and nearby text): The term <math>K_{fp}</math> in Equations (11.52) and (11.53) should be <math>(K_{fp}+I)</math>~~, where~~ <math>I</math> is the identity matrix. In the text immediately after Equation (11.51), the term "positive-definite" should be eliminated. In the text immediately after Equation (11.53), <math>K_{fp}</math> should be replaced by <math>(K_{fp}+I)</math>.		* Chapter 11.5, Equations (11.52) and (11.53) (and nearby text): The term <math>K_{fp}</math> in Equations (11.52) and (11.53) should be <math>(K_{fp}+I)</math>. (<math>I</math> is the identity matrix.) In the text immediately after Equation (11.51), the term "positive-definite" should be eliminated. In the text immediately after Equation (11.53), <math>K_{fp}</math> should be replaced by <math>(K_{fp}+I)</math>.

	== Updated first edition: Minor typos, etc., no danger of misunderstanding ([[Modern Robotics Errata, First Edition Version 1\|Errata for original first edition here]]) ==		== Updated first edition: Minor typos, etc., no danger of misunderstanding ([[Modern Robotics Errata, First Edition Version 1\|Errata for original first edition here]]) ==

Lynch: /* Chapter 11 */

2022-02-03T13:44:14Z

Chapter 11

← Older revision		Revision as of 08:44, 3 February 2022
Line 30:		Line 30:
	=== Chapter 11 ===		=== Chapter 11 ===

	* The one-sentence paragraph near the beginning of Chapter 11.3.3, after Equation (11.16): Change "As in Section 11.3.2 ... where <math>k_p, k_i > 0</math>." should be changed to "The entries of the diagonal gain matrices <math>K_p, K_i \in \mathbb{R}^{6 \times 6}</math> should be positive." (Currently it says that these matrices shold have the form <math>k_p I</math> and <math>k_i I</math>, but the units for a twist are different (first three units are angular velocities, last three units are linear velocities). So you may wish to use one positive value for the top three elements on the diagonal and a different positive value for the bottom three elements on the diagonal.)		* The one-sentence paragraph near the beginning of Chapter 11.3.3, after Equation (11.16): Change "As in Section 11.3.2 ... where <math>k_p, k_i > 0</math>." should be changed to "The diagonal entries of the diagonal gain matrices <math>K_p, K_i \in \mathbb{R}^{6 \times 6}</math> should be positive." (Currently it says that these matrices shold have the form <math>k_p I</math> and <math>k_i I</math>, but the units for a twist are different (first three units are angular velocities, last three units are linear velocities). So you may wish to use one positive value for the top three elements on the diagonal and a different positive value for the bottom three elements on the diagonal.)
	* Chapter 11.5, Equations (11.52) and (11.53) (and nearby text): The term <math>K_{fp}</math> in Equations (11.52) and (11.53) should be <math>(K_{fp}+I)</math>, where <math>I</math> is the identity matrix. In the text immediately after Equation (11.51), the term "positive-definite" should be eliminated. In the text immediately after Equation (11.53), <math>K_{fp}</math> should be replaced by <math>(K_{fp}+I)</math>.		* Chapter 11.5, Equations (11.52) and (11.53) (and nearby text): The term <math>K_{fp}</math> in Equations (11.52) and (11.53) should be <math>(K_{fp}+I)</math>, where <math>I</math> is the identity matrix. In the text immediately after Equation (11.51), the term "positive-definite" should be eliminated. In the text immediately after Equation (11.53), <math>K_{fp}</math> should be replaced by <math>(K_{fp}+I)</math>.

Lynch at 13:43, 3 February 2022

2022-02-03T13:43:39Z

← Older revision		Revision as of 08:43, 3 February 2022
Line 27:		Line 27:
	F^\prime_{ij}(q) = -\frac{\partial P^\prime_{ij}}{\partial f_i(q)} = \frac{k}{\\|f_i(q) - c_j\\|^4} (f_i(q) - c_j) \in \mathbb{R}^3.		F^\prime_{ij}(q) = -\frac{\partial P^\prime_{ij}}{\partial f_i(q)} = \frac{k}{\\|f_i(q) - c_j\\|^4} (f_i(q) - c_j) \in \mathbb{R}^3.
	</math>		</math>


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

	* The one-sentence paragraph near the beginning of Chapter 11.3.3, after Equation (11.16): Change "As in Section 11.3.2 ... where <math>k_p, k_i > 0</math> should be changed to "The entries of the diagonal gain matrices <math>K_p, K_i \in \mathbb{R}^6</math> should be positive." (Currently it says that these matrices shold have the form <math>k_p I</math> and <math>k_i I</math>, but the units for a twist are different (first three units are angular velocities, last three units are linear velocities). So you may wish to use one positive value for the top three elements on the diagonal and a different positive value for the bottom three elements on the diagonal.)		* The one-sentence paragraph near the beginning of Chapter 11.3.3, after Equation (11.16): Change "As in Section 11.3.2 ... where <math>k_p, k_i > 0</math>." should be changed to "The entries of the diagonal gain matrices <math>K_p, K_i \in \mathbb{R}^{6 \times 6}</math> should be positive." (Currently it says that these matrices shold have the form <math>k_p I</math> and <math>k_i I</math>, but the units for a twist are different (first three units are angular velocities, last three units are linear velocities). So you may wish to use one positive value for the top three elements on the diagonal and a different positive value for the bottom three elements on the diagonal.)
	* Chapter 11.5, Equations (11.52) and (11.53) (and nearby text): The term <math>K_{fp}</math> in Equations (11.52) and (11.53) should be <math>(K_{fp}+I)</math>, where <math>I</math> is the identity matrix. In the text immediately after Equation (11.51), the term "positive-definite" should be eliminated. In the text immediately after Equation (11.53), <math>K_{fp}</math> should be replaced by <math>(K_{fp}+I)</math>.		* Chapter 11.5, Equations (11.52) and (11.53) (and nearby text): The term <math>K_{fp}</math> in Equations (11.52) and (11.53) should be <math>(K_{fp}+I)</math>, where <math>I</math> is the identity matrix. In the text immediately after Equation (11.51), the term "positive-definite" should be eliminated. In the text immediately after Equation (11.53), <math>K_{fp}</math> should be replaced by <math>(K_{fp}+I)</math>.

Lynch at 13:42, 3 February 2022

2022-02-03T13:42:05Z

← Older revision		Revision as of 08:42, 3 February 2022
Line 9:		Line 9:
	=== Chapter 3 ===		=== Chapter 3 ===

	* (printed version only) At the end of the introduction Exercise 3.16, it says "origin of {b} is at (0,2,0) is {s}" but "is {s}" should be "in {s}".		* (printed version only) At the end of the introduction Exercise 3.16, it says "origin of {b} is at (0,2,0) is {s}", but "is {s}" should be "in {s}".
	* Exercise 3.20, Figure 3.26: In the figure, the y and z axes for the {a}, {b}, and {c} frames are switched (y should point forward and z should point up). Also, the space frame is located at the bottom of the small wheel, directly below the {a} frame.		* Exercise 3.20, Figure 3.26: In the figure, the y and z axes for the {a}, {b}, and {c} frames are switched (y should point forward and z should point up). Also, the space frame is located at the bottom of the small wheel, directly below the {a} frame.
	* (printed version only) Exercise 3.25(a): the element in the third row and third column of the matrix <math>A</math> should be 0 (it is incorrectly written as 1).'''		* (printed version only) Exercise 3.25(a): the element in the third row and third column of the matrix <math>A</math> should be 0. (It is incorrectly written as 1.)'''

	=== Chapter 4 ===		=== Chapter 4 ===

	* Exercise 4.21: The question should begin "For each <math>T</math> below..." (instead of "For each <math>T \in SE(3)</math> below...") ~~since~~ the first part of the problem is determining whether <math>T</math> is indeed an element of <math>SE(3)</math>.		* Exercise 4.21: The question should begin "For each <math>T</math> below..." instead of "For each <math>T \in SE(3)</math> below...". (Since the first part of the problem is determining whether <math>T</math> is indeed an element of <math>SE(3)</math>.

	=== Chapter 8 ===		=== Chapter 8 ===
Line 23:		Line 23:
	=== Chapter 10 ===		=== Chapter 10 ===

	* Second displayed equation of Chapter 10.6.3 (Workspace Potential): As it is written, this equation (which involves a partial derivative with respect to the robot's configuration <math>q</math>) already gives the repulsive generalized force <math>F_{ij}(q)</math>, i.e., the Jacobian is already embedded, obviating the subsequent development. To fit the rest of the development, the partial derivative in this equation should be with respect to <math>f_i(q)</math>. So the equation should read		* Second displayed equation of Chapter 10.6.3 (Workspace Potential): As it is written, this equation (which involves a partial derivative with respect to the robot's configuration <math>q</math>) already gives the repulsive generalized force <math>F_{ij}(q)</math>, i.e., the Jacobian is already embedded, obviating the subsequent development. To fit the rest of the development, the partial derivative in this equation should be with respect to <math>f_i(q)</math>. So the equation should read:
	<math>		<math>
	F^\prime_{ij}(q) = -\frac{\partial P^\prime_{ij}}{\partial f_i(q)} = \frac{k}{\\|f_i(q) - c_j\\|^4} (f_i(q) - c_j) \in \mathbb{R}^3.		F^\prime_{ij}(q) = -\frac{\partial P^\prime_{ij}}{\partial f_i(q)} = \frac{k}{\\|f_i(q) - c_j\\|^4} (f_i(q) - c_j) \in \mathbb{R}^3.
Line 31:		Line 31:
	=== Chapter 11 ===		=== Chapter 11 ===

	* The one-sentence paragraph near the beginning of Chapter 11.3.3, after Equation (11.16), ~~says~~ ~~that~~ the diagonal gain matrices ~~take~~ the form <math>k_p I</math> and <math>k_i I</math>. ~~But~~ the units for a twist are different (first three units are angular velocities, last three units are linear velocities). So you may wish to use one positive value for the top three elements on the diagonal and a different positive value for the bottom three elements on the diagonal. ~~Whatever you choose, the gain matrices should be positive definite.~~		* The one-sentence paragraph near the beginning of Chapter 11.3.3, after Equation (11.16): Change "As in Section 11.3.2 ... where <math>k_p, k_i > 0</math> should be changed to "The entries of the diagonal gain matrices <math>K_p, K_i \in \mathbb{R}^6</math> should be positive." (Currently it says that these matrices shold have the form <math>k_p I</math> and <math>k_i I</math>, but the units for a twist are different (first three units are angular velocities, last three units are linear velocities). So you may wish to use one positive value for the top three elements on the diagonal and a different positive value for the bottom three elements on the diagonal.)
	* Chapter 11.5, Equations (11.52) and (11.53) (and nearby text): The term <math>K_{fp}</math> in Equations (11.52) and (11.53) should be <math>(K_{fp}+I)</math>, where <math>I</math> is the identity matrix. In the text immediately after Equation (11.51), the term "positive-definite" should be eliminated. In the text immediately after Equation (11.53), <math>K_{fp}</math> should be replaced by <math>(K_{fp}+I)</math>.		* Chapter 11.5, Equations (11.52) and (11.53) (and nearby text): The term <math>K_{fp}</math> in Equations (11.52) and (11.53) should be <math>(K_{fp}+I)</math>, where <math>I</math> is the identity matrix. In the text immediately after Equation (11.51), the term "positive-definite" should be eliminated. In the text immediately after Equation (11.53), <math>K_{fp}</math> should be replaced by <math>(K_{fp}+I)</math>.