# CDS 101/110 - Introduction to Feedback and Control

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

CDS 101/110a | Schedule | Recitations | FAQ | () |

## Contents |

## Overview

**Monday:** Introduction to Feedback (Slides, MP3)

The goal of this lecture is to introduce some of the basic ideas in feedback systems and provide examples that will allow students to identify and recognize control systems in their everyday world. Two major principles of control--robustness through feedback and design of dynamics--are emphasized throughout the lecture. CDS 101/110 course administration is also covered.

**Wednesday:** Introduction to Control (Slides, MP3)

Control has many applications in engineering systems. This lecture gives an overview of some of those applications and talks about future research directions in control, dynamics and systems. Additional course details about CDS 110 and the course project are also given.

**Friday:** MATLAB Tutorial (Elisa Franco)

This lecture providse an introduction to MATLAB, a software program that will be used extensively throughout the course and on the homework assignments. CDS 110 students who have not used MATLAB in previous courses are strongly encouraged to attend.

## Handouts

Monday | Wednesday (CDS 110) | Friday |

## Reading

- K. J. Åström and R. M. Murray,, Preprint, 2006..

## Homework

This homework set is designed to provide some examples and intuition about feedback and control systems. The first problem problem is a conceptual problem designed to provide examples of feedback and control systems in the everyday world. The second problem involves using MATLAB to explore the performance of a engineering feedback system by manually tuning gains and evaluating the resulting performance. The advanced problems (CDS 110 only) further explore these concepts through articles in the popular press about control systems and additional MATLAB/SIMULINK examples.

- SIMULINK speed control module (for problem #2): hw1cruise.mdl,
- Government to Require More Car Safety, Associated Press, September 2006 (problem #4)

## FAQ

**Monday**

- Can you make the graphics bigger so that we can see them?
- Can you speak more slowly?
- How are stability, performance, and robustness different? They seem very similar
- How do I create a FAQ for CDS 101/110?
- How would you make the dynamics in the cruise control example more realistic?
- I did not understand robustness
- I didn't catch the fly video. Is it available online?
- Is a high gain good in the speed control example?
- Is control a type of negative feedback?
- Is it possible to take CDS 110b without taking CDS 110a?
- Is it true that feedback systems are in closed loop by definition?
- Is kp (the gain of the system) dimensionless?
- Is there room for learning in control systems theory?
- Latency wasn't mentioned in the example; does it affect robustness?
- Please turn the AC higher.
- Should we bring our computers with Matlab installed to the review Friday?
- The additional material and schedule of cds210.
- The last few slides went by too fast
- What do you mean by "gain" in the speed control example? What relation to sensing does it have?
- What is an example of an open loop system
- What is the schedule for 101 in the 4th, 6th, & 8th weeks?
- What should we do with unsused Mud Cards?
- Where can I get a more detailed description of how the flyball governor works?
- Why does instability imply poor performance?

**Wednesday**

- Are there any advances in applying feedback modeling to social systems other than in an economic sense?
- Can I turn my homework by email (pdf file)?
- Can the environment be considered a system state?
- How do I save the mp3 files?
- How does feedback help the X-29 experimental aircraft?
- In lecture 1.2, y(x) was used as a function of the state variables. Is y a generic function of vector x?
- It's a bit unclear to me when you talk about "error" in PID control
- What are methods for determining errors in a real system?
- What is fuzzy logic?

**Friday**

**Homework**

- In problem 1 (CDS 110)/problem 2 (CDS 101), download cruise-ctrl.mdl, NOT cruisedyn.m
- Problem 1 -- Do I need to know exactly how a device works to use it as an example?
- Problem 2b -- Does this mean exactly or at least fifty percent?
- Problem 4 -- Do I have to sum n i(t)?
- SIMULINK License
- What is the policy for using symbolic manipulation on homework sets?