Control Engineering Introduction Kim Do Wan HANBAT NATIONAL

Control Engineering Introduction Kim, Do Wan HANBAT NATIONAL UNIVERSITY

Outline Course introduction q What is the control engineering? q Analysis and design objectives q Course objectives q

Course introduction Automatic control q For junior student q Text book: q ¾ q Control Systems Engineering by Norman S. Nise 2 major tests (45%+45%), homeworks (5%), attendance (5%)

Course introduction q Covers ¾ ¾ ¾ ¾ Introduction (chap. 1) Modeling in frequency and time domain (chap. 2 -3) Model reduction (chap. 5) Time responses (chap. 4) Steady-state errors (chap. 7) Stability (chap. 6) Root locus techniques (chap. 8)

Course introduction q Instructor: Kim, Do Wan Professor Researcher Postdoc Professor B. S. M. S. Ph. D. 2002. 2 2004. 2 2007. 8 Yonsei University 2007. 10 2008. 1 2009. 3 2010. 3 UC, Berkeley HANBAT NATIONAL UNIVERSITY

Course introduction q Instructor: Do Wan Kim ¾ Research interests: discrete-time, sampled-data, and digital nonlinear control systems, linear and nonlinear systems with nonlinear perturbations, fuzzy systems, and digital redesign. 042 -821 -1097 ¾ N 3 215 ¾

What is the control engineering? q Definition of control systems ¾ A control system is a set of devices (plant, controller) that can provide a desired system response.

What is the control engineering? q Definition of control systems ¾ q A control system is a set of devices (plant, controller) that can provide a desired system response. In input-output sense ¾ An example in the morning

What is the control engineering? ¾ In elevator ¡ Input? Output?

What is the control engineering? q Control systems attempt to either Regulation or Tracking Regulation – to maintain systems response at CONSTANT desired values system response ¾ constant desired value time

What is the control engineering? ¾ Regulation – to maintain systems response at CONSTANT desired values system response constant desired value time

What is the control engineering? ¾ Tracking – to make system response follow continually CHANGING desired values system response continually changing desired value time

What is the control engineering? q Representation of control system ¾ Differential equation ¡ Kirchhoff’s voltage law and current law, Newton’s laws ¾ Transfer function ¾ State space equation ¡ nth order differential equation= n 1 st order differential equations ¡ Ex)

What is the control engineering? q Representation of control system ¾ Block Diagram ¾ Signal flow graph

What is the control engineering? q Open-loop vs Closed-loop (Feedback control) ¾ Open-loop systems Input ¡ ¡ ¡ ¾ Controller Plant Output No direct comparison between the input and the output. Sensitive to disturbances Feedforward control. Closed-loop (feedback control) systems Input + error Controller Plant Output ¡ ¡ ¡ Direct comparison between the input and the output. Less sensitive to disturbances Feedback Control.

What is the control engineering? ¾ Examples

What is the control engineering? q Classification

What is the control engineering? q Classification Control system Distributed Lumped

What is the control engineering? q Classification Control system Distributed Lumped Stochastic Deterministic

What is the control engineering? q Classification Control system Distributed Lumped Stochastic Deterministic Discrete-time Continuous-time

What is the control engineering? q Classification Control system Distributed Lumped Stochastic Deterministic Discrete-time Continuous-time Nonlinear Linear (L)

What is the control engineering? q Classification Control system Distributed Lumped Stochastic Deterministic Discrete-time Continuous-time Nonlinear Linear (L) Time-varying Time-invariant (TI)

Classification q Linear vs Nonlinear ¾ q Linear system principle: satisfies the following superposition Time-invariant vs Time-varying ¾ Check whether its parameter is a function in time or not.

Classification ¾ Examples:

What is the control engineering? q Examples: robot, missile, ….

What is the control engineering? q Control engineering is concerned with analysis, design, and implementation of control systems

Analysis and Design Objectives Stability q Steady-state response (steady-state error) q Transient response (Response speed) q

Analysis and Design Objectives Stability q Steady-state response (steady-state error) q Transient response (Response speed) q If it returns to its original position, it is STABLE.

Analysis and Design Objectives Stability q Steady-state response (steady-state error) q Transient response (Response speed) q If it returns to its original position, it is STABLE. If it does NOT returns to its original position, it is UNSTABLE.

Analysis and Design Objectives Stability q Steady-state response (steady-state error) q Transient response (Response speed) q

Analysis and Design Objectives Stability q Steady-state response (steady-state error) q Transient response (Response speed) q Controller

Analysis and Design Objectives Stability q Steady-state response (steady-state error) q Transient response (Response speed) q

Analysis and Design Objectives Stability q Steady-state response (steady-state error) q Transient response (Response speed) q steady-state error:

Analysis and Design Objectives Stability q Steady-state response (steady-state error) q Transient response (Response speed) q Fast Response Slow Response

Analysis and Design Objectives q An example: inverted pendulum control system

Analysis and Design Objectives q An example: inverted pendulum control system desired system response

Analysis and Design Objectives q An example: inverted pendulum control system

Design procedure q Process

Design procedure q Test input

Course objectives q Students completing control engineering should: Understand control theory. ¾ Understand utility of computer tools. ¾

Course objectives q Students completing control engineering should: Understand control theory. ¾ Understand utility of computer tools. ¾ Control yourself !