Mech - Recent changes [en]

Engineering Analysis 3

Lynch — Fri, 17 Apr 2026 13:56:00 GMT

Homework

Mobile Manipulation Capstone

Lynch — Tue, 07 Apr 2026 13:02:15 GMT

Introduction, and the CSV Mobile Manipulation youBot CoppeliaSim Scene

Engineering Analysis 3

Lynch — Thu, 02 Apr 2026 15:25:03 GMT

Office Hours

@@ Line 17: / Line 17: @@
 * Section 22: Lecture 1-1:50 MWF, Annenberg G21
 ** Instructor: Prof. Jeremy Keys, jeremy.keys@northwestern.edu
-** TAs: Daiki Shoji, daiki.shoji@northwestern.edu
+** TAs: Daiki Shoji, daiki.shoji@northwestern.edu; Itzel Salgado, itzelsalgado2026@u.northwestern.edu
 * Section 23: Lecture 2-2:50 MWF, Annenberg G21
 ** Instructor: Prof. Cheng Sun, c-sun@northwestern.edu
@@ Line 50: / Line 50: @@
 |-
 ! Wed
-| Prof. Keys || Banerjee || Prof. Lynch (canceled Apr 8) || Liu || Silver || Liu || Prof. Sun || Banerjee || Meem
+| Prof. Keys || Banerjee || Welbeck || Liu || Silver || Liu || Prof. Sun || Banerjee || Meem
 |-
 ! Thurs
-|  ||  || Silver || Yang || Yang || Yang || x || x || x
+| Salgado || Salgado || Silver || Yang || Yang || Yang || x || x || x
 |-
 ! Fri
-|  ||  || Banerjee || Banerjee || Welbeck || Meem || Meem || Meem ||
+| Salgado ||  || Banerjee || Banerjee || Prof. Lynch || Meem || Meem || Meem || Salgado
 |}
@@ Line 135: / Line 135: @@
 ==Homework==
-Homeworks are due each Thursday (except the first and last week) at 5 PM, and homework solutions will be released Thursday nights. Homeworks must be submitted electronically through Canvas. Late submissions will not be accepted. '''No exceptions, so please don't ask.''' Your lowest homework grade will be dropped from the calculation of your homework score to accommodate an emergency, celebration of a religious holiday, homeworks that are just a few minutes late, homeworks that you completed on time but forgot to submit, or any other circumstance.
+Homeworks are due each Thursday (except the first and last week) at 5 PM, and homework solutions will be released Thursday nights. Homeworks must be submitted electronically through Canvas. Late submissions will not be accepted. '''No exceptions, so please don't ask.''' Your lowest homework grade will be dropped from the calculation of your homework score to accommodate any emergency, celebration of a religious holiday, homeworks that are just a few minutes late, homeworks that you completed on time but forgot to submit or submitted incorrectly, or any other circumstance. This is for fairness across all sections and all circumstances, and to allow us to post solutions soon after the homework due time, to aid you with your studying. We are giving everyone one "free" accommodation by dropping your lowest score.
 Homework must be submitted in a single pdf file, titled LastnameFirstname.pdf (substitute in your own last name [family name] and first name [given name]). All work must be clear and legible or you will not receive full credit. Make sure to show your thought process in case multiple steps are involved; don't just give an answer. Some homeworks involve Matlab programming. You should comment your code so it is easy to understand. When including code in the pdf, make sure to print the code as pdf (don't take images of code, for example) so the code is copy-and-pastable.

@@ Line 15: / Line 15: @@
 The final output of your software will be a comma-separated values (csv) text file that specifies the configurations of the chassis and the arm, the angles of the four wheels, and the state of the gripper (open or closed) as a function of time.  This specification of the position-controlled youBot will then be "played" on the CoppeliaSim simulator to see if your trajectory succeeds in solving the task.  [[Writing_a_CSV_File|'''This page''']] has information on writing csv files in Python, MATLAB, and Mathematica.
-'''[[Getting_Started_with_the_CoppeliaSim_Simulator|Make sure you have a working CoppeliaSim installation]]''' (from Course 1 of the [https://www.coursera.org/specializations/modernrobotics Coursera specialization]).  [[CoppeliaSim_Introduction#Scene_6:_CSV_Mobile_Manipulation_youBot|'''This project uses Scene 6 (CSV Mobile Manipulation youBot) from the CoppeliaSim Introduction wiki page''']].  You should download it and test it with its sample csv file, to see what a solution looks like.  (Even if you have downloaded it before, download it again before you begin your project, to make sure you have the most up-to-date version of this scene.) Leave the block's initial and goal configurations as the default.  The default initial block configuration is at <math>(x,y,\theta) = (1~\text{m}, 0~\text{m}, 0~\text{rad})</math> and the final block configuration is at <math>(x,y,\theta) = (0~\text{m},-1~\text{m},-\pi/2~\text{rad})</math>.
+'''[[Getting_Started_with_the_CoppeliaSim_Simulator|Make sure you have a working CoppeliaSim installation]]''' (from Course 1 of the [https://www.coursera.org/specializations/modernrobotics Coursera specialization]).  [[CoppeliaSim_Introduction#Scene_6:_CSV_Mobile_Manipulation_youBot|'''This project uses Scene 6 (CSV Mobile Manipulation youBot) from the CoppeliaSim Introduction wiki page''']].  You should download it and test it with its sample csv file, to see what a solution looks like.  (Even if you have downloaded it before, download it again before you begin your project, to make sure you have the most up-to-date version of this scene.) Leave the block's initial and goal configurations as the default.  The default initial block configuration is at <math>(x,y,\theta)=(1\text{m},0\text{m},0\text{rad})</math>
+and the final block configuration is at <math>(x,y,\theta)=(0\text{m},-1\text{m},-\pi/2\text{rad})</math>.
 Unlike previous projects, where we used CoppeliaSim to simply animate the robot's motion, in this project CoppeliaSim will use a physics simulator to simulate the interaction of the youBot with the block.  In other words, if the gripper closes on the block in the wrong position or orientation, the block may simply slide out of the grasp.  The interaction between the robot and the block is governed by a physics simulator, often called a "physics engine," which approximately accounts for friction, mass, inertial, and other properties.  CoppeliaSim has different physics engines which you can select, including Bullet and ODE, but ODE is the default for Scene 6.
@@ Line 86: / Line 87: @@
 [[image:Yb-book.png|right|500px|thumb|This figure illustrates the arm at its home configuration (all joint angles zero) and the frames {s}, {b}, {0}, and {e}.  For the image on the right, joint axes 1 and 5 (not shown) point upward and joint axes 2, 3, and 4 are out of the screen.  Click to make the image bigger.]]
-[[image:Yb-base-capstone.png|right|300px|thumb|A top view of the omnidirectional mobile base.  The forward-backward distance between the wheels is <math>2l = 0.47</math> meters and the side-to-side distance between wheels is <math>2w = 0.3</math> meters.  The radius of each wheel is <math>r = 0.0475</math> meters.  The forward driving and "free sliding" direction <math>\gamma</math> of each wheel is indicated.]]
+[[image:Yb-base-capstone.png|right|300px|thumb|A top view of the omnidirectional mobile base.  The forward-backward distance between the wheels is
+<math>
+l = 0.47
+</math>
+meters and the side-to-side distance between wheels is <math>2w = 0.3</math> meters.  The radius of each wheel is <math>r = 0.0475</math> meters.  The forward driving and "free sliding" direction <math>\gamma</math> of each wheel is indicated.]]
-[[image:Youbot-gripper.png|right|300px|thumb|The gripper and the end-effector frame {e}, which has an origin midway between the fingers of the gripper.  The minimum opening distance of the gripper is <math>d_{1,\text{min}} = 2</math> cm, the maximum opening distance is <math>d_{1,\text{max}} = 7</math> cm, the interior length of the fingers is <math>d_{2} = 3.5</math> cm, and the distance from the base of the fingers to the frame {e} is <math>d_{3} = 4.3</math> cm.  The axis <math>\hat{\text{x}}_{\text{e}}</math> is into the screen.]]
+[[image:Youbot-gripper.png|right|300px|thumb|The gripper and the end-effector frame {e}, which has an origin midway between the fingers of the gripper.  The minimum opening distance of the gripper is <math>d_{1,\text{min}} = 2</math> cm, the maximum opening distance is <math>d_{1,\text{max}} = 7</math> cm, the interior length of the fingers is <math>d_{2} = 3.5</math> cm, and the distance from the base of the fingers to the frame {e} is <math>d_{3}=4.3</math> cm.  The axis <math>\hat{\text{x}}_{\text{e}}</math> is into the screen.]]
 [[image:Block-capstone.png|right|300px|thumb|The object being manipulated is a cube, 5 cm x 5 cm x 5 cm.  The cube's frame {c} is at its center, and the axes are aligned with the edges of the cube.]]
-The configuration of the frame {b} of the mobile base, relative to the frame {s} on the floor, is described by the 3-vector <math>q = (\phi,x,y)</math> or the <math>SE(3)</math> matrix
+The configuration of the frame {b} of the mobile base, relative to the frame {s} on the floor, is described by the 3-vector
+<math>q=(\phi,x,y)
+</math>
+or the
+<math>
+SE(3)
+</math> matrix
 <math> T_{sb}(q) = \left[\begin{array}{cccc} \cos \phi & -\sin \phi & 0 & x \\ \sin \phi & \cos \phi & 0 & y \\ 0 & 0 & 1 & 0.0963 \\ 0 & 0 & 0 & 1 \end{array}\right]</math>
@@ Line 188: / Line 199: @@
 '''Input:'''
 * A 12-vector representing the current configuration of the robot (3 variables for the chassis configuration, 5 variables for the arm configuration, and 4 variables for the wheel angles).
-* A 9-vector of controls indicating the wheel speeds <math>u</math> (4 variables) and the arm joint speeds <math>\dot{\theta}</math> (5 variables).
+* A 9-vector of controls indicating the wheel speeds
+<math>
+u
+</math>
+(4 variables) and the arm joint speeds
+<math>
+\dot{\theta}
+</math>
+(5 variables).
 * A timestep <math>\Delta t</math>.
 * A positive real value indicating the maximum angular speed of the arm joints and the wheels.  For example, if this value is 12.3, the angular speed of the wheels and arm joints is limited to the range [-12.3 radians/s, 12.3 radians/s].  Any speed in the 9-vector of controls that is outside this range will be set to the nearest boundary of the range.  If you don't want speed limits, just use a very large number.  If you prefer, your function can accept separate speed limits for the wheels and arm joints.
@@ Line 199: / Line 218: @@
 * new chassis configuration is obtained from odometry, as described in Chapter 13.4
-'''Testing the <tt>NextState</tt> function:''' To test your <tt>NextState</tt> function, you should embed it in a program that takes an initial configuration of the youBot and simulates constant controls for one second.  For example, you can set <math>\Delta t</math> to 0.01 seconds and run a loop that calls <tt>NextState</tt> 100 times with constant controls <math>(u,\dot{\theta})</math>.  Your program should write a csv file, where each line has 13 values separated by commas (the 12-vector consisting of 3 chassis configuration variables, the 5 arm joint angles, and the 4 wheel angles, plus a "0" for "gripper open") representing the robot's configuration after each integration step.  Then you should load the csv file into the CSV Mobile Manipulation youBot CoppeliaSim scene and watch the animation of the constant controls to see if your <tt>NextState</tt> function is working properly (and to check your ability to produce a csv file).
+'''Testing the <tt>NextState</tt> function:''' To test your <tt>NextState</tt> function, you should embed it in a program that takes an initial configuration of the youBot and simulates constant controls for one second.  For example, you can set
+<math>
+\Delta t
+</math>
+to 0.01 seconds and run a loop that calls <tt>NextState</tt> 100 times with constant controls <math>(u,\dot{\theta})</math>.  Your program should write a csv file, where each line has 13 values separated by commas (the 12-vector consisting of 3 chassis configuration variables, the 5 arm joint angles, and the 4 wheel angles, plus a "0" for "gripper open") representing the robot's configuration after each integration step.  Then you should load the csv file into the CSV Mobile Manipulation youBot CoppeliaSim scene and watch the animation of the constant controls to see if your <tt>NextState</tt> function is working properly (and to check your ability to produce a csv file).
 [[Writing_a_CSV_File|'''This page''']] has information on writing csv files in Python, MATLAB, and Mathematica.

@@ Line 5: / Line 5: @@
 ==Instructors, TAs, and Sections==
-Each section covers the same material, at approximately the same pace, following the same readings from the web textbook (below), though each instructor's lecture notes and teaching style may be different. All sections have the same homeworks, due the same time and day. The quizzes in each section will be different. You may go to a discussion section you are not registered for if there is room in the room.
+Each section covers the same material, at approximately the same pace, following the same readings from the web textbook (below), though each instructor's lecture notes and teaching style may be different. All sections have the same homeworks, due the same time and day. The quizzes in each section will be different. You may go to a discussion session you are not registered for if there is room in the room.
 '''Our first class is Tuesday March 31, following a Monday schedule.'''
@@ Line 17: / Line 17: @@
 * Section 22: Lecture 1-1:50 MWF, Annenberg G21
 ** Instructor: Prof. Jeremy Keys, jeremy.keys@northwestern.edu
-** TAs: Daiki Shoji, daiki.shoji@northwestern.edu; Richmond Odufisan, AlesanmiOdufisan2028@u.northwestern.edu
+** TAs: Daiki Shoji, daiki.shoji@northwestern.edu
 * Section 23: Lecture 2-2:50 MWF, Annenberg G21
 ** Instructor: Prof. Cheng Sun, c-sun@northwestern.edu
 ** TAs:  Ari Silver, AryehSilver2024@u.northwestern.edu; Subin Yang, SubinYang2028@u.northwestern.edu
 * '''Discussion sessions''': Discussion sessions, led by TAs, will be held during your class time on Tuesdays in Tech L211, starting in the second week of class.
+* Course assistant: Yunsoo Yoon, AdrienneYoon2027@u.northwestern.edu
 <!--
-supergrader/course assistant: Yunsoo Yoon
-supergrader: Yiran Huang
-graders: Derek Dietz, Meghna Sundaram
 -->
@@ Line 53: / Line 50: @@
 |-
 ! Wed
-| Prof. Keys || Banerjee || Prof. Lynch || Liu || Silver || Liu || Prof. Sun || Banerjee || Meem
+| Prof. Keys || Banerjee || Prof. Lynch (canceled Apr 8) || Liu || Silver || Liu || Prof. Sun || Banerjee || Meem
 |-
 ! Thurs
-| Odufisan || Odufisan || Silver || Yang || Yang || Yang || x || x || x
+|  ||  || Silver || Yang || Yang || Yang || x || x || x
 |-
 ! Fri
-| Odufisan || Odufisan || Banerjee || Banerjee || Welbeck || Meem || Meem || Meem ||
+|  ||  || Banerjee || Banerjee || Welbeck || Meem || Meem || Meem ||
 |}
@@ Line 99: / Line 96: @@
 '''Accessible NU'''
-If you need accommodation in this course because of a disability, contact [http://www.northwestern.edu/accessiblenu/ Accessible NU] immediately.
+If you need an accommodation in this course, contact [http://www.northwestern.edu/accessiblenu/ Accessible NU] immediately.
 '''Religious Holidays'''
@@ Line 116: / Line 113: @@
 * Monday May 18
 * Friday June 5 (last day of class)
+There is no separate final exam.
-Students must attend the quiz in their own section, and the quizzes in each section will be different. There is no final exam. No electronic devices (phones, tablets, laptops, watches, etc.) are allowed during quizzes. No notes or scratch paper.
+Students must attend quizzes in their own section, and the quizzes in each section will be different. There is no final exam. No electronic devices (phones, tablets, laptops, watches, etc.) are allowed during quizzes. No notes or scratch paper.
 Quizzes focus mostly on recent material (e.g., material not covered on previous quizzes), but they may require anything from the course up until the most recent homework.