Chap2. Modeling in the Frequency Domain Automatic Control Chap2. Modeling in the Frequency Domain Kim, Do Wan HANBAT NATIONAL UNIVERSITY
Outline Laplace transform Electrical network Mechanical system
Why do we study Laplace transform
Why do we study Laplace transform Differential Equation
Why do we study Laplace transform Transfer Function Differential Equation Solution
Why do we study Laplace transform Transfer Function Differential Equation Algebraic Equation Solution
Why do we study Laplace transform Transfer Function Time-domain Frequency-domain Differential Equation Algebraic Equation Solution
Why do we study Laplace transform Transfer Function Arrangement Differential Equation Algebraic Equation Solution
Partial Fraction Expansion Laplace transform Why do we study Laplace transform Transfer Function Arrangement Differential Equation Algebraic Equation Algebraic manipulation Solution Partial Fraction Expansion
Partial Fraction Expansion Laplace transform Why do we study Laplace transform Transfer Function Arrangement Differential Equation Algebraic Equation Algebraic manipulation Solution Partial Fraction Expansion Look-up table
Inverse definition (Inverse Laplace transform)
Laplace transform Example 2.1: Solution:
Laplace transform theorems Laplace transform table
Laplace transform Example 2.1: Solution:
Example 2.2: Find the inverse Laplace transform of Solution:
Partial-fraction Expansion Laplace transform Partial-fraction Expansion To find the inverse Laplace transform of a complicated function with Case 1: Roots of the denominator of are real and distinct. Example: where hence
Laplace transform
Case 2: Roots of the denominator of are real and repeated. Laplace transform Case 2: Roots of the denominator of are real and repeated. Example:
Case 3: Roots of the denominator of are complex or imaginary Laplace transform Case 3: Roots of the denominator of are complex or imaginary Example:
Laplace transform
Skill- Assessment Exercise 2. 1 Skill- Assessment Exercise 2. 2 Laplace transform Skill- Assessment Exercise 2. 1 Skill- Assessment Exercise 2. 2
Transfer function Definition Pole, Zero Block diagram Laplace transform Transfer function Definition Pole, Zero Block diagram
Laplace transform Evaluation Pole, Zero
Skill-Assessment Exercise 2.3 Skill-Assessment Exercise 2.4 Laplace transform Example 2.5 Skill-Assessment Exercise 2.3 Skill-Assessment Exercise 2.4 Skill-Assessment Exercise 2.5 Example 2.3 (Solution)
Impedance Relationships Electrical Network Impedance Relationships
Example: Transfer function relating the input voltage to the current Electrical Network Example: Transfer function relating the input voltage to the current Kirfchhoff's voltage law: LT Transfer function
Electrical Network Examples 2.6, 2.10
Mechanical system Translational System
Mechanical system Example 2.16
Governing Principle: sum of all forces are zero. Now, Mechanical system Governing Principle: sum of all forces are zero. Now, So, the differential equation is
Homework Problems 1, 2, 7, 8, 16, 22 Read Chap. 3.2 carefully!