# ME 449 Robotic Manipulation (Archive Fall 2017)

**Fall Quarter 2017**

- Instructor: Prof. Kevin Lynch
- Meeting: 2:00-2:50, MWF, Abbott Auditorium Pancoe
- TAs: Huan Weng, HuanWeng2015@u.northwestern.edu, and Taosha Fan, TaoshaFan2015@u.northwestern.edu
- Office hours: Tech B222, MW 3-4 (Lynch), Tech A211 Tues 2-3:30 (Weng or Fan)
- course website: http://hades.mech.northwestern.edu/index.php/ME_449_Robotic_Manipulation

## Course Summary

Mechanics of robotic manipulation, computer representations and algorithms for manipulation planning, and applications to industrial automation, parts feeding, grasping, fixturing, and assembly.

## Grading

- 50% exams
- 35% assignments (HWs, video/reading comprehension "quick quizzes"; low scores dropped)
- 10% student lecture and learning materials
- 5% engagement, providing helpful feedback to other students, and student-assigned in-class projects

## Course Text and Software

All of these resources are available at **the homepage for the book**.

- Get the book. Purchase the printed book, published by Cambridge University Press, or download the preprint version of the book.
**Download the book software from GitHub.****Download the V-REP robot simulator.**After you've installed it, choose "File > Open scene..." and open any of the scenes. Press the "Play" button and verify that the simulator is working.**Click here for information about the simulator, and the ME 449 scenes for the UR5 and youbot mobile manipulator.**

## Video Lectures

Video supplements to the reading can be found at **http://modernrobotics.northwestern.edu**. If you prefer to watch the videos as playlists in the youtube environment, you can **go here instead**. These links are also available from the **book's homepage**.

In general, I recommend that you first watch the videos to get a quick understanding of the material of the chapter, then follow up by reading. The videos are short and dense, so don't expect to get by only watching the videos. You will need to read the book, then do the exercises, to gain mastery of the material.

## Student Lectures

Each student will work in a small team to deliver one lecture during the quarter. Your lecture should not be too similar to the video lectures already online. The main purposes of the student lectures are

- To provide your fellow students another perspective, other than my own, on the material. Maybe your way of explaining it will be more intuitive than mine, at least for some people. Unlike my lectures, which cover a lot of ground quickly, your lecture should have at least one worked example and slow things down a bit. You don't have to cover
**all**topics of the videos and reading that were due for that day. You can choose one or a subset of topics and slow down. You can even choose a topic in that day's reading that is not covered in the videos. - To generate new learning materials that others can benefit from. These could be posted to the book website (e.g., worked exercises, videos, etc.).
- To have you take ownership of your learning. There is no better way to learn the material than to figure out how to teach it.

On a student lecture day, this is a general (but flexible) guideline:

- 5 minutes for the video/reading comprehension "quick quiz."
- 15 minutes lecture. How you do your lecture is up to you, but everyone in the lecture team should be involved. You could make a video and then play it in front of the class, and then take questions. You could write on the chalkboard. You could use props, or videos you find online, or animations you make. You could ask questions and involve the class. You should work through at least one example or exercise that you create (not one from the book) that makes some of the concepts concrete. An ideal lecture would be engaging and informative.
- 5 minutes of constructive feedback from the class (what worked well, what could have been clearer, but always constructive).
- 25 minutes of the class working in small groups on an assignment you give. Ideally the assignment would be interesting and challenging, and would elicit questions if students don't fully understand the material. Students do not necessarily have to be able to get a "right" answer in the timeframe of the class; the assignment should just help them to learn. The assignment cannot be taken from the book. The student lecturers and the instructors will circulate and help the small groups. Small groups of students will turn in their group work at the end of class. Each assignment should have the names of the group members who worked on it.

After your lecture, within one week your lecture team should provide me with:

- [Whole team] A video of your lecture. You should arrange for a classmate to take a video of your lecture (e.g., with a cell phone propped up against books, so it doesn't move). Then post the lecture to YouTube and send me the link. You can keep the video private or you can make it public; up to you.
- [Whole team] An electronic version of your in-class assignment with solution, suitable for posting to the website. A pdf file is probably the best format.
- [Each member of the team] Each member of the team should confidentially email me a fair self-assessment of each individual's contribution to the lecture. You get 10 points to assign for each member of the team, so if your team has 3 students, you have 30 points to assign. Ideally your distribution would be 10/10/10. If one student did not contribute much, the distribution might be 12/12/6, or if one student did most of the work, it might be 16/7/7. In either of these cases, a
**brief**explanation would be helpful. These are just to help me understand how the team functioned. - Anything else. This will likely be nothing in most cases, but maybe you found a useful website you'd like to share, or created some MATLAB code you'd like to share, etc.

I encourage you to meet with me during office hours if you have any questions or if you'd like to discuss your ideas for your lecture.

## Approximate Syllabus and Reading

- Chapter 2, Configuration Space (weeks 1-2)
- Chapter 3, Rigid-Body Motions (weeks 2-3)
- Chapter 4, Forward Kinematics (week 4); section 4.2 is optional
- Chapter 5, Velocity Kinematics and Statics (week 5)
- Chapter 6, Inverse Kinematics (week 6); focus on section 6.2
- Chapter 8, Dynamics of Open Chains (weeks 6-7); skip sections 8.4, 8.8, and 8.9
- Chapter 9, Trajectory Generation (week 8); focus on sections 9.1 and 9.4
- Chapter 11, Robot Control (week 9); focus on sections 11.1 through 11.4
- Chapter 13, Wheeled Mobile Robots (week 10); skip section 13.3

## Assignments

Assignments are graded based on correctness, how well you organize your homework (it should be easy to understand your thinking and easy to find your responses), and how well you follow the submission instructions below. You will lose points if you don't follow these instructions.

If you ever think a problem is stated incorrectly, not enough information is given, or it is impossible to solve, don't panic! Simply make a reasonable assumption that will allow you to solve the problem (but clearly state what this assumption is), or indicate why it is not possible to solve the problem.

**Instructions for uploading assignments to Canvas:**

0. **Upload on time! Late submissions are not accepted.** The cutoff time is 30 minutes before class the day the assignment is due.

1. Only upload one zip file or rar file for each assignment;

2. In your zip file or rar file, include all source codes in their original form, such as .cpp, .m, .py, .nb.

3. If there is a demo, combine the screen shots into one SEPARATE pdf file, OR, show the results in one SEPARATE .txt file (DON'T show them in your source code file format, e.g. .nb file), and include it in the zip file (or rar file).

4. Always include output of your code running on the exercises, particularly in case the grader has problems running your code. Also, always create a script (for example, titled ex6-9 or something) that the grader can easily invoke for each exercise. Don't expect the grader to search through your code to find sample code to cut-and-paste. Make it as easy as possible for the grader (you can include a "README" file in your solutions, for example).

5. Please name the upload file in the following format: LastName_FirstName.zip.

## Detailed Syllabus (Under Construction)

**Click here for a graphical view of the class schedule, including student lectures.**

Homeworks are due at the beginning of class every Wednesday, unless otherwise noted. You will watch the videos and do the reading in advance of class using the material, as noted in the syllabus below. A typical weekly schedule will consist of:

- M: Video/reading comprehension quick quiz and help with homework.
- W: Video/reading comprehension quick quiz, homework solutions, plus
**EITHER**student lecture**OR**quiz preparation. - F: Video/reading comprehension quick quiz plus
**EITHER**student lecture**OR**quiz.

**Class 1** (W 9/20)

- Welcome to the course and course website. Structure of the course (HW due Wed, student-generated lectures and learning materials, in-class assignments, feedback on student lectures, occasional Friday quizzes). Book, software, (lack of) D-H parameters, syllabus, V-REP simulator, office hours.

At home:

- Videos: first 3 videos of Chapter 2, through Chapter 2.2
- Reading: Chapters 2.1 and 2.2
- Software: download github software with book, install V-REP and verify that you can use Scenes 1 and 2 (the UR5)
**HW1, due 1:30 PM 9/27**: Exercises 2.3, 2.9, 2.20, 2.29. Also, create your own example system with closed loops, something not in the book, and solve for the degrees of freedom using Grubler's formula. Make it something that exists or occurs in common experience, not necessarily a robot. Imagine using it to teach someone about Grubler's formula.

**Class 2** (F 9/22)

- Quick quiz
- Sample student lecture

At home:

- Videos: 2 videos on Chapter 2.3
- Reading: Chapter 2.3

**Class 3** (M 9/25)

- Quick quiz
- Bring your laptop, demo V-REP UR5 scenes
- Help with HW

At home:

- Videos: 2 videos, Chapter 2.4 and 2.5
- Reading: Chapters 2.4 and 2.5
- Turn in HW1

**Class 4** (W 9/27)

- Quick quiz
- Solutions to HW1; student examples of Grubler's formula

At home:

- Videos: first 3 videos of Chapter 3, through Chapter 3.2.1
- Reading: through Chapter 3.2.1
**HW2, due 1:30 PM 10/4**:- 1) Exercise 3.1, except the y_a axis points in the direction (1,0,0).
- 2) Exercise 3.2, except p = (1,2,3).
- 3) Exercise 3.5.
- 4) Exercise 3.9.
- 5) In Figure 1.1(a) of the book is an image of a UR5 robot, with a frame at its base and a frame at its end-effector. Eyeballing the end-effector frame, approximately write the rotation matrix that represents the end-effector frame orientation relative to the base frame. Your rotation matrix should satisfy the properties of a rotation matrix (R^T R = I, det(R) = 1). The x-axes are in red, the y-axes are in green, and the z-axes are in blue.
- 6) Write a program that takes a set of exponential coordinates for rotation from the user as input. It then prints out the following: (a) the corresponding unit rotation axis and the angle of rotation about that axis; (b) the so(3) 3x3 matrix representation of the exponential coordinates; (c) the 3x3 SO(3) rotation matrix corresponding to the exponential coordinates; (d) the inverse of the rotation matrix from (c); (e) the 3x3 so(3) matrix log of the matrix from (d); and (f) the corresponding exponential coordinates for the so(3) matrix (e). Use the code from the book and write your program in Mathematica, MATLAB, or Python. Turn in your code and the output of an example run using (0.5, 1, 0) as the input to part (a).
- 7) Write a function that returns "true" if a given 3x3 matrix is with a distance epsilon of being a rotation matrix and "false" otherwise. It is up to you to define the "distance" between a random 3x3 real matrix and members of SO(3). Test the function on two matrices, neither of which is exactly in SO(3), but one of which is close (so the result is "true") and one of which is not. Turn in your code and provide the test run output, which also outputs the distance to SO(3) that you defined.
- 8) Following up on the previous exercise: describe (don't implement, unless you want to) a function that takes a "close by" 3x3 matrix and returns the closest rotation matrix. How would you use the fact that R^T R - I must be equal to zero to modify the initial 3x3 matrix to make it a "close by" rotation matrix? Would the function be iterative? You are free to do some research online, but as always,
**cite your sources**!

**Class 5** (F 9/29)

- Quick quiz
- Lecture

At home:

- Videos: videos 4-6 of Chapter 3, through Chapter 3.2.3
- Reading: through Chapter 3.2.3

**Class 6** (M 10/2)

- Quick quiz
- Help with HW

At home:

- Videos: videos 7-9 of Chapter 3, Chapters 3.3.1 and 3.3.2
- Reading: same sections

**Class 7** (W 10/4)

- Quick quiz
- Exam prep

At home:

- Videos: videos 10-11, Chapter 3.3.3 and 3.4
- Reading: same sections
**HW3, due 1:30 PM 10/11**: Exercises 3.16, 3.17, 3.27, 3.31, and 3.48 (as always, for programming assignments, turn in your code and sample output demonstrating it).

**Class 8** (F 10/6)

- EXAM 1

At home:

- Videos: video 1 of Chapter 4, through Chapter 4.1.2
- Reading: same sections

**Class 9** (M 10/9)

- Quick quiz
- Help with HW

At home:

- Videos: videos 2-3 of Chapter 4, Chapter 4.1.3
- Reading: same sections

**Class 10** (W 10/11)

- Quick quiz
- Student lecture 1 (Pawar, Subramanian, Goyal, Cai)

At home:

- Videos: video 1 of Chapter 5, up to (not including) Chapter 5.1
- Reading: same sections
**HW4, due 1:30 PM 10/18**: Exercises 4.2, 4.8, 4.14, and 5.7(a). Question 5: In Chapter 3.5 (Summary), there is a list of analogies between rotations and rigid-body motions. Read it carefully and report anything that is either unclear or incorrect.

**Class 11** (F 10/13)

- Quick quiz
- Student lecture 2 (Wang, Wu, Xia, Zheng)

At home:

- Videos: video 2 of Chapter 5, Chapter 5.1.1
- Reading: same sections

**Class 12** (M 10/16)

- Quick quiz
- Help with HW

At home:

- Videos: videos 3 and 4 of Chapter 5, Chapter 5.1.2 through 5.2
- Reading: same sections

**Class 13** (W 10/18)

- Quick quiz
- Student lecture 3 (Wiznitzers, Hutson, Spies)

At home:

- Videos: videos 5 and 6 of Chapter 5, Chapter 5.3 and 5.4
- Reading: same sections
**HW5, due 1:30 PM 10/25**: Exercises 5.2, 5.3, 5.23, 5.25, 6.7, and 6.8.

**Class 14** (F 10/20)

- Quick quiz
- Student lecture 4 (Don, Chien, Husain, Sulaiman)

At home:

- Videos: videos 1 and 2 of Chapter 6,
- Reading: intro of Chapter 6 and Chapter 6.2

**Class 15** (M 10/23)

- Quick quiz
- Help with HW

At home:

- Videos: video 3 of Chapter 6
- Reading: Chapter 6.2

**Class 16** (W 10/25)

- Quick quiz
- Exam prep

At home:

- Videos: video 1 of Chapter 8, through 8.1.1
- Reading: same sections
- HW6, due 1:30 PM 11/1

**Class 17 ** (F 10/27)

- EXAM 2

At home:

- Videos: video 2 of Chapter 8, through 8.1.2
- Reading: same sections

**Class 18** (M 10/30)

- Quick quiz
- Help with HW

At home:

- Videos: video 3 of Chapter 8, through 8.1.3
- Reading: same sections

**Class 19** (W 11/1)

- Quick quiz
- Student lecture 5 (Zhang, Zhu, Meng, Luo)

At home:

- Videos: videos 4-5 of Chapter 8, through 8.2
- Reading: same sections
**HW7, due 1:30 PM 11/8**: Exercises 8.2, 8.3, 8.11 (you should build on the MR code), and 8.15(a).

**Class 20** (F 11/3)

- Quick quiz
- Student lecture 6 (Lyu, Yi, Wang, Swissler)

At home:

- Videos: video 6 of Chapter 8, up to (not including) 8.4
- Reading: same sections

**Class 21** (M 11/6)

- Quick quiz
- Help with HW

At home:

- Videos: video 7 of Chapter 8, Chapter 8.5 (skip 8.4)
- Reading: same sections

**Class 22** (W 11/8)

- Quick quiz
- Student lecture 7 (Warren, Kilaru, Wang, Mandana)

At home:

- Videos: videos 1-2 of Chapter 9, through Chapter 9.2
- Reading: same sections
**HW8, due 1:30 PM 11/15**: Exercises 8.15(b) (use your previous results from 8.15(a), and turn in any code you write as well as a V-REP movie of your simulation), 8.14 (turn in your testable code and evidence your code returns similar results), 9.14, and 9.26.

**Class 23** (F 11/10)

- Quick quiz
- Student lecture 8 (Wang, Dai, Ma, Peng)

At home:

- Videos: video 4 of Chapter 9, Chapter 9.4 - 9.4.1 (skip 9.3)
- Reading: same sections

**Class 24** (M 11/13)

- Quick quiz
- Help with HW

At home:

- Videos: videos 5-6 of Chapter 9, up to (not including) Chapter 9.5
- Reading: same sections

**Class 25** (W 11/15)

- Quick quiz
- Exam prep

At home:

- Videos: videos 1-3 of Chapter 11, up to (not including) Chapter 11.2.2.1
- Reading: same sections
**Final project. This project is part of the assignment grade, cannot be dropped, and has the weight of 2 normal assignments.**The assignment is split into two parts: a relatively simple Part I, due after 1 week, followed by the programming-heavy Part II, due during finals week. You will receive a single grade for the entire assignment, after Part II has been submitted.**Part I, due 1:30 PM 11/22**: Exercise 13.33 (a) and (b). Turn in your solutions (handwritten or typed) and any code you wrote.**Part II, due 11:59 PM 12/6**: Exercise 13.33 (c), (d), and (e). Turn in 1) any solutions (handwritten or typed), 2) your code, 3) any plots you created with your code, 4) your short V-REP videos (made using the youbot csv animation scene), and 5) the .csv files corresponding to the videos.

**Class 26** (F 11/17)

- EXAM 3

At home:

- Videos: videos 4-5 of Chapter 11, Chapter 11.2.2.1 and 11.2.2.2
- Reading: same sections

**Class 27** (M 11/20)

- Quick quiz
- Help with HW

At home:

- Videos: videos 6-8 of Chapter 11, Chapter 11.3
- Reading: same sections
**Turn in Part I of your final project on Canvas.**

**Class 28** (W 11/22)

- Quick quiz
- Student lecture 9 (Abiney, Aubrun, Anthony, Alston)

At home:

- Videos: videos 1-3 of Chapter 13, through Chapter 13.2
- Reading: same sections

**Class 29** (M 11/27)

- Quick quiz
- Help with HW

At home:

- Reading: odometry and mobile manipulation, Chapter 13.4 and 13.5

**Class 30** (W 11/29)

- Quick quiz
- Student lecture 10 (Miller, Berrueta, Davis, Tobia)

At home:

- Final assignment work

**Class 31** (F 12/1)

- Student lecture 11 (Fernandez, Lutzen, SaLoutos, Iwankiw)

At home:

**Your final project is due on Canvas by 11:59 PM on Wednesday Dec 6.**