CƠ SỞ TỰ ĐỘNG

Giảng viên: Nguyễn Đức HoàngBộ môn Điều Khiển Tự Động

Khoa Điện – Điện TửĐại Học Bách Khoa Tp.HCM

Email: ndhoang@hcmut.edu.vn

MÔN HỌC

Nội dung môn học (10 Nội dung môn học (10 chương)chương)

(14 tuần = 42 tiết LT + 14 tiết BT)(14 tuần = 42 tiết LT + 14 tiết BT)Chương 1: Giới thiệu về hệ thống điều khiển tự động

Chương 2: Mô hình toán học hệ thống liên tục

Chương 3: Đặc tính động học

Chương 4: Khảo sát tính ổn định của hệ thống

Chương 5: Chất lượng hệ thống điều khiển

Chương 6: Thiết kế hệ thống tuyến tính liên tục

Chương 7: Mô hình toán học hệ rời rạc

Chương 8: Phân tích hệ rời rạc

Chương 9: Thiết kế hệ rời rạc

Chương 10: Ứng dụng

Tài liệu tham khảoTài liệu tham khảo

Giáo trình: Giáo trình: Lý thuyết điều khiển Lý thuyết điều khiển

tự độngtự độngNguyễn Thị Phương Hà – Huỳnh Thái HoàngNguyễn Thị Phương Hà – Huỳnh Thái Hoàng

NXB Đại Học Quốc Gia TpHCMNXB Đại Học Quốc Gia TpHCM

Bài tập: Bài tập: Bài tập điểu khiển tự Bài tập điểu khiển tự

độngđộngNguyễn Thị Phương HàNguyễn Thị Phương Hà

Tài liệu: Tài liệu:

Automatic Control SystemAutomatic Control System

Modern Control System Theory Modern Control System Theory

and Designand Design

Đánh giáĐánh giá

Thi giữa kỳ : 20%Thi cuối kỳ : 80%Có cộng điểm BT vào điểm thi cuối kỳ (≤1.0đ)

GIỚI THIỆU VỀ HỆ THỐNG GIỚI THIỆU VỀ HỆ THỐNG ĐIỀU KHIỂN TỰ ĐỘNGĐIỀU KHIỂN TỰ ĐỘNG

CHƯƠNG 1

Control Systems 6

1769

• James Watt’s steam engine and governor developed.The Watt steam engine is often used to mark the beginning of the Industrial Revolution in Great Britain. During the Industrial Revolution, great strides were made in the development of mechanization, a technology preceding automation.

Control

• Control is a sequence of decisions aimed at the attainment of specified objectives in an environment of uncertainty and presence of disturbances.

Control system

• A control system is an arrangement of physical components connected or related in such a manner as to command, direct, or regulate itself or another system.

Input

• The input is the stimulus, excitation or command applied to a control system.

• Typically from external energy source, usually in order to produce a specified response from the control system.

Output

• The output is the actual response obtained from a control system.

• It may or may not be equal to specified response implied by the input.

History of Automatic Control

Prior to World War II

A main impetus for the use of feedback in the United States was the development of the telephone system and electronic feedback amplifiers by Bode, Nyquist, and Black at Bell Telephone Laboratories.

Prior to World War II

The Russian theory tended to utilize a time-domain formulation using differential equations.

World War II

Design and construct:• automatic airplane pilots, • gun-positioning systems, • radar antenna control systems.

Sputnik and space age

The time-domain methods developed by Liapunov, Minorsky, and others have met with great interest in the last two decades.

Recent time

Recent theories of optimal control developed by L.S. Pontryagin in the former Soviet Union and R. Bellman in the United States, and studies of robust systems, have contributed to the interest in time-domain methods.

Terms and Concepts

Two Types of Control Systems

• Open Loop– No feedback– Difficult to control

output with accuracy

• Closed Loop– Must have feedback– Must have sensor on output– Almost always negative

feedback

Open-loop and closed-loop systems

Open-loop control

An open-loop control system utilizes an actuating device to control the process directly without using feedback.

A common example of an open-loop control system is an electric toaster in the kitchen.

Closed-loop control

A closed-loop control system uses a measurement of the output and feedback of this signal to compare it with the desired output.

A person steering an automobile by looking at

the auto’s location on the road and making the appropriate adjustments.

Control Systems

Manual control system

Goal: Regulate the level of fluid by adjusting the output valve.

The input is a reference level of fluid and is memorized by operator.The power amplifier is the operator.The sensor is visual.Operator compares the actual level with the desired level and opens or closes the valve ( actuator).

29

The level of fluid in a tank control.

30

Multivariable control system

A robot is a computer-controlledmachine.

Industrial robotics is a particular field of automation in which the robot is designed to substitute for human labor.

The Honda P3 humanoid robot.

The Control System Design Process

• Design is the process of conceiving or inventing the forms, parts, and details of a system to achieve a specified purpose.

Engineering design

Engineering design

Trade-off The result of making a judgment about how to

compromise between conflicting criteria.

Given a process, how to design a feedback control system?

Three steps:

• Modeling. Obtain mathematical description of the systems.

• Analysis. Analyze the properties of the system.

• Design. Given a plant, design a controller based on performance specifications.

Design examples

Rotating disk speed control

Control Systems

Step 1. Control goal

• Design a system that will held a rotating disk at a constant speed. Ensure that the actual speed of rotation is within a specified percentage of desired speed.

Control Systems

Step 2. Variable to be controlled

• Speed of rotation disc

Control Systems

Step 3. Control design specification

• Design a system that will ensure that the actual speed of rotation is within a specified percentage of desired speed.

Control Systems

Step 4 Preliminary system configuration

Control Systems

Step 4 Preliminary system configuration

Control Systems

Insulin delivery system

The blood glucose and insulin concentrations for a healthy person.

Control Systems

Step 1. Control goal

• Design a system to regulate the blood sugar concentration of a diabetic by controlled dispensing of insulin.

Control Systems

Step 2. Variable to be controlled

• Blood glucose concentration

Control Systems

Step 3. Control design specification

• Provide a blood glucose level for the diabetic that closely approximates the glucose level of a healthy person.

Control Systems

Step 4 Preliminary system configurations

Control Systems

Disk drive read system

Control Systems

Control Systems

Step 1. Control goal

• Design a system that will held the position the reader head to read the data stored on a track on the disk.

Control Systems

Step 2. Variable to be controlled

• Position of the reader head

Control Systems

Step 3. Control design specification

• Design a system that will ensure that the head : - “flies” above the disk at a distance of less than 100 nm, - with the position accuracy is 1 m,- with speed from track to track 50 ms

Control Systems

Step 4 Preliminary system configuration

Control Systems

P1.8 Student-teacher learning process

• Construct a feedback model of the learning process and identify each block of the system.

Control Systems

P1.8 Student-teacher learning process

Inverted pendulum control

• E1.11 Sketch the block diagram of a feedback control system. Identify the process, sensor, actuator, and controller.The objective is keep the pendulum in the upright position ( = 0), in the presence of disturbances.

Control Systems

Control Systems

Inverted pendulum control