Applied Linear Systems

These are notes I jotted down for my own reference when I was new to this field. I took the graduate-level Applied Linear Systems course taught by Dr. Steve Southward, an amazing professor, and the snippets here come from his class notes.

At first, I just wanted a reference I could return to whenever I needed to refresh the ideas. Later, I decided to organize the notes a bit more and put them on my website.

This whole thing is still under improvement.

1. Open Loop and Second-Order System Basics

Basics of Open Loop

DC Gain Explained

Natural Frequency, Poles, Damping (2nd Order System)

Damping Ratio and Resonance

Bandwidth Definition

Decibel Interpretation

2. Closed Loop and Frequency-Domain Thinking

Basics of Closed Loop

Closed Loop System with Feedback Control

Gain Margin and Phase Margin

Controller or Compensator Design

3. MATLAB / LTI Object Toolbox

Creating a LTI Object in MATLAB - Part 1

Creating a LTI Object in MATLAB - Part 2 (Conversion)

State-Space Info from LTI Object

Impulse Response Function Plotting

sgrid Code for s-plane

Pole Placement (Const Damping and Const Freq Line) s-plane

4. Why State-Space Matters

Why Do We Bother with State-Space Realization

Intuition (Mapping) of State-Space Realization

Transfer Function Matrix - A Misconception

5. Controllability and Full-State Feedback

Controllability 1

Controllability 2

TODO - Why Observability and Controllability are Dual Problems

Full State Feedback - Part 1

6. Observers and Augmented Systems

Luenberger Observer (State Estimation) - Full State Feedback - 2

Luenberger Observer - 2

Observer (State Estimator) and Augmented System

Augmented System - 2 with Control Command

7. Integral Control / LQR / Wrap-Up

Integral Control (LQR) - Part 1

Integral Control (LQR) - Part 2

Wrapping Up - 1

Future Appendix

Future Appendix - ODE Solving in MATLAB (with Function)

Final Project Explanation