14 | Harmonic Input

By the end of this section, you should be able to

  1. Read log-scale plot

  2. Use Bode plot to determine magnitude and phase of output signal

  3. Find closed-form steady-state outputs for linear systems with simple harmonic input

  4. Use normalized Bode plot to design systems to operate away from resonance

  5. Understand sensor dynamic range from their Bode plot

  6. Design simple analog LP and HP filters

Introduction

Example: Analytically Calculating Gain and Phase

The Bode Diagram

Example 1: Finding the SS Output

2nd-Order System Response to Harmonic Input

Example 2: 2nd-Order System SS Response

Centripetal Force refresher: https://www.khanacademy.org/science/physics/centripetal-force-and-gravitation/centripetal-forces/a/what-is-centripetal-force

Note that the sin term comes from the fact that we are accounting for only the vertical component of the force at any time. The horizontal component is ignored in these examples.

Transmissibility, Vibration Isolator & Relative-Frequency Bode Diagram

Example 3: Designing a 2nd-Order System for a Desired Response

Multi-DOF Systems

Sensors & Filters

Sensors Introduction

Filters Introduction

Passive LP Filter Example

Passive HP Filter Example

Higher-Order Filter Example

Lecture Code