This document provides an introduction to control systems. It defines a control system as interconnecting components that provide a desired response. A control system uses feedback to compare actual output to desired output and actuators to obtain the desired response. Examples of modern control systems include flight control, robotics, chemical processes, communications networks, automotive systems, and more. The document also provides examples of position control systems and discusses control system design.

1. CONTROL SYSTEMS

2. Introduction
System – An interconnection of elements and devices for a desired purpose.
Control System – An interconnection of components forming a system configuration
that will provide a desired response.
Process – The device, plant, or system
under control. The input and output
relationship represents the cause-and-
effect relationship of the process.

3. Introduction
Multivariable Control System
Open-Loop Control Systems
utilize a controller or control
actuator to obtain the desired
response.
Closed-Loop Control Systems
utilizes feedback to compare
the actual output to the
desired output response.

4. January 11, 2005
4
Example : Insect Flight (Biological system)
• More information:
– M. D. Dickinson, Solving the mystery
of insect flight, Scientific American,
June 2001.
ACTUATION
two wings
(di-ptera)
specialized
“power”
muscles
SENSING
neural
superposition
eyes
hind wing
gyroscopes
(halteres)
COMPUTATION
~500,000 neurons

5. 5
Control = Sensing + Computation + Actuation
Sense
Vehicle Speed
Compute
Control “Law”
Actuate
Gas Pedal
In Feedback “Loop”
• Goals
– Stability: system maintains desired operating point (hold steady speed)
– Performance: system responds rapidly to changes (accelerate to 65 mph)
– Robustness: system tolerates perturbations in dynamics (mass, drag, etc)

6. Closed-loop feedback system with external disturbances and measurement noise

7. Typical Control Systems Block diagram

8. Examples of Modern Control Systems
Water-level float regulator

9. Examples of Modern Control Systems

10. Examples of Modern Control Systems

11. 11
EXAMPLE : Coordinated Control of Unmanned Systems

12. Modern Engineering Applications of Control
• Flight Control Systems
– Modern commercial and military
aircraft are “fly by wire”
– Autoland systems, unmanned
aerial vehicles (UAVs) are already
in place
• Robotics
– High accuracy positioning for
flexible manufacturing
– Remote environments: space,
sea, non-invasive surgery, etc.
• Chemical Process Control
– Regulation of flow rates,
temperature, concentrations,
etc.
– Long time scales, but only crude
models of process
• Communications and Networks
– Amplifiers and repeaters
– Congestion control of the
Internet
– Power management for wireless
communications
• Automotive
– Engine control, transmission
control, cruise control, climate
control, etc
– Luxury sedans: 12 control
devices in 1976, 42 in 1988, 67 in
1991
• AND MANY MORE...

13. The Internet: Largest feedback system built by man
IP
Web FTP Mail News Video Audio ping napster
Applications
TCP SCTP UDP ICMP
Transport protocols
Ethernet 802.11 Satellite
Optical
Power lines Bluetooth
ATM
Link technologies

14. Examples of Modern Control Systems

15. Examples of Modern Control Systems

16. Examples of Modern Control Systems

17. Control System Design

19. Design Example

20. Design Example

21. Design Example

22. Design Example

25. Design Example Insulin delivery control system

26. Design Example

27. Antenna Azimuth: An Introduction to Position
Control Systems

28. Antenna Azimuth: An Introduction to Position
Control Systems

29. References
Dorf R. C. and Bishop R. H, “Modern control systems”,
Addison-Wesley Longman Inc., Eighth Edition, Indian
reprint, 1999
Norman Nise, “Control System Engineering”, John Wiley &
Sons, Inc., Sixth Edition, 2011.