1. Introduction to Automatic Control and Intelligent Systems
Prof Kang Li

2. Lecture objectives: -
Introduce the concept of control and intelligent systems in an engineering context
Indicate the wide range of applications
Give brief historical background
Teaching Method: 24 x 1 hour lectures + Tutorials

3. Textbooks:
Dorf, R C, Bishop, R H: Modern Control Systems. 10th Ed. Addison-Wesley 2004
Franklin, G F, Powell, J D and Emami-Naeini, A: Feedback Control of Dynamic Systems. 3rd Ed. Addison-Wesley 1994
Nise, N S: Control Systems Engineering. 3rd Ed. The Benjamin/Cummings Publishing Company, Inc
Phillips, C L and Harbor, R D: Feedback Control Systems. Prentice/Hall 1988
DiStefano III, J J, Stubberud, A R and Williams, I J: Feedback and Control Systems. Shaum Pub. Co 1967
Cannon, R H: Dynamics of Physical Systems. McGraw-Hill 1967
Douce, J L: Introduction to the Mathematics of Servomechanisms. EUP 1963

4. Module Content:
Introduction - 1st chapter of any textbook on Control
2-5 Modelling - Dorf ch 2, Canon chs 1,2
6-8 Mathematical tools - Laplace transforms, Transfer functions, Block diagrams - Dorf ch 2
9-10 Characteristics of Feedback Systems - Dorf ch 4
11-12 Performance measures for Feedback Systems - Dorf ch 5
13-16 Stability considerations - Hurwitz criterion, Nyquist criterion - Douce ch4, Dorf chs 6,8,9
17-24 Introduction to intelligent systems and control

5. 1.1 Preliminaries
Module objectives, outline and textbooks as per handout sheet.

6. 1.2 The Concept of Control
We are familiar with the concept of control from such areas as quality control, financial control, production control, stock control, command and control etc. These activities have common features:- there is a system, an objective, an input, freedom to take action, constraints and disturbances. For example the ‘system’ from the perspective of the manager of a chemical plant might be the entire plant.

7. For an engineer in the plant the ‘system’ may be one reaction vessel:-
It is really this latter context in which our module is set. We want to be able to understand, analyse, design and implement control schemes for such engineering applications. However it is worth noting that the concepts also apply in business, commerce, medicine etc. Some of the most effective control systems operate in our bodies eg temperature control, heart rate, hand movements, walking etc.

8. 1.3 Range of Applications semiconductor manufacture eg Intel, NISRC
electrical power generation eg PowerGen
chemical plant eg Kevlar, DuPont
food processing eg Dale Farm
water and sewage eg DoE Water Executive
car manufacture eg robots, machine tools at Visteon (Ford Motor Company)
automobiles eg electrical system, auto pilot, eg Mercedes
aircraft eg autopilot, Bombardier Shorts
rocket launching eg NASA
satellites eg Global Positioning System
space exploration eg Mars rover
domestic eg heating, CD or video player etc

9. 1.4 Three Important Control Strategies
Open-loop, Feed-forward and Feedback or Closed-loop
(a) Open-loop strategy
(b) Feed-forward strategy

10. (c) closed-loop strategy or feedback strategy

11. 1.5 Definitions
An open-loop control system is one in which the control action is independent of the output.
A closed-loop control system is one in which the control action is somehow dependent on the output.

12. 1.6 Historical Background
Watt’s fly-ball governor 1769
Fantail windmill
Bode, Nyquist etc on feedback amplifiers 1930s
World war s
Space program1960s
Automation and robots 1960
Computers and microprocessors
Intelligent systems, Neural networks

13. Centrifugal governor
A centrifugal governor is a specific type of governor that controls the speed of an engine by regulating the amount of fuel admitted, so as to maintain a near constant speed whatever the load or fuel supply conditions. It uses the principle of proportional control.
It is most obviously seen on steam engines where it regulates the admission of steam into the cylinder(s). It is also found on internal combustion engines and variously fueled turbines.

14. It is connected to a throttle valve and to the prime mover
It is connected to a throttle valve and to the prime mover. The action of the governor is dependent on centrifugal force. As the speed of the prime mover increases, the central spindle of the governor rotates at a faster rate and the two masses move outwards, and this motion is translated by the series of rods and arms to the throttle valve, reducing its aperture. The rate of steam entering the cylinder is thus reduced and the speed of the prime mover falls. If the speed of the prime mover falls, the reverse effect occurs and the throttle valve opens further.

16. Fantail windmill
Fantail was mounted on the cap of the mill for turning the mill automatically into the wind through gearing and a rack round the top of the tower.