CDS 101/110a, Fall 2007 - FAQ

WARNING: This page is for a previous year. See current course homepage to find most recent page available.

CDS 101/110a

Schedule

Recitations

FAQ

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This page contains frequently asked questions for CDS 101/110. You can find FAQs for individual lectures and homework sets on the topics page for each week, available via the course schedule.

Additional FAQs:

• Full list of CDS 101/110a FAQs from previous years

Week 1

• Can you make the graphics bigger so that we can see them?
• How do I create a FAQ for CDS 101/110?
• I did not understand robustness
• Is control a type of negative feedback?
• Is it possible to take CDS 110b without taking CDS 110a?
• Is there room for learning in control systems theory?
• Latency wasn't mentioned in the example; does it affect robustness?
• Should we bring our computers with Matlab installed to the review Friday?
• Where can I get a more detailed description of how the flyball governor works?
• Why does instability imply poor performance?

• Are there any advances in applying feedback modeling to social systems other than in an economic sense?
• Can the environment be considered a system state?
• It's a bit unclear to me when you talk about "error" in PID control

Homework:

• For problem 1, how detailed should my description of a control system be?

Week 2

• How do we read the simulated predator-prey graph?
• Is there any open source software we can use instead of MATLAB?
• What are the Di parameters in the power grid model?
• What is a finite state machine and how does it relate to the traffic example?
• Where can I find a theoretical definition of dynamical system?
• Why was there only one damper in the mass/spring model?

• Could you give a precise definition for "Control Law"?

Homework:

• Do I need to turn in a block diagram of my PI controller for problem 2?
• Does my Simulink model need to change gears?
• On prob. 2, how closely do I have to follow the block diagram in the book?
• Problem 1d correction, hint

Week 3

• How are the z variables defined on slide 10, Lecture 3-1?
• How was V(x) derived on slide 13 of Lecture 3-1?

• Was the equation for V(q) for the spring mass example missing a transpose?
• Where can I find the proof to the Lyapunov Theorem?

Homework:

• Can we use phaseplot in exercise 2?
• Typo in exercise 4

Week 4

• Is it standard practice to use degrees to represent the phase in frequency response analysis?
• The homework set took 15 hours and this class is not my only priority!

Homework:

• How do we investigate stability of a system that has inputs?
• HW4 Prob 2a Correction
• HW4 Prob 3 Hint
• HW4 Prob 4a Formula Correction
• HW4 Prob 4c Correction

Week 5

• Can you recommend a good linear algebra resource?
• Could we move office hours?
• What is matrix rank and how do i calculate it?

Midterm:

• Will the midterm cover material from Week 5?

Week 6

• Can you explain the axes of the Bode plot better?

Homework:

• Can I cascade (multiply) transfer functions in MATLAB?
• Question 1
• Question 3
• Question 4

Week 7

• Lecture 7.1 bugs
• Why counterclockwise encirclements of -1?
• Why does Z≠0 correspond to instability?

• What is the Nyquist contour for discrete systems?

Homework:

• "HW6 Question 3"
• Bandwidth command, HW 6
• Hw 6 Problem 2
• HW 6 Question 4

Week 8

• Can you make the graphics bigger so that we can see them?
• Can you speak more slowly?

Homework:

• HW 7 Prob 1 Comments
• HW 7 Prob 3 Hint
• HW 7 Problem 2
• HW 7 problem 4

Week 9

• Why is it better to use a lead controller than a PD controller?
• Why would it matter if the loop transfer function had high amplification of radio waves if nothing else could respond to such high frequency inputs?

Homework:

• How is the slope of the gain curve related to robustness?
• HW8 Problem 1 Hints
• HW8 Problem 3
• HW8 problem 4
• Margin command help page

Week 10

Homework: