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ME464-Sys Dyn & Ctrl Spring-2013 Dr. Shaukat Ali
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ME464-Sys Dyn & Ctrl Spring-2013 Dr. Shaukat Ali
Chapter 1Introduction to Control Systems
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ME464-Sys Dyn & Ctrl Spring-2013 Dr. Shaukat Ali
Control engineering is concerned with the analysis and design of
goal-oriented systems.
Control System: An interconnection of components forming a
system
configuration that will provide a desired system response.
Input: A stimulus, excitation or actuating signal applied to a
control
system from an external energy source.
Output: An actual response obtained from a control system.
Control Systems
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ME464-Sys Dyn & Ctrl Spring-2013 Dr. Shaukat Ali
The control of an industrial process (manufacturing, production,
and so on) by automatic rather than manual means is called
automation.
Control systems play an increasingly important role in the
development and advancement of modern civilization and
technology.
Practically every aspect of our day-to-day activities is
affected by some type of control systems, including the following
areas:
generation of energy, transmission of energy, communication,
transportation (cars, trains, ships, aircrafts, space crafts),
industrial processes, power systems, instrumentation,
Micro-Electro-Mechanical Systems (MEMS), robotics, consumer
electronics, biology, medicine, etc.
Control Systems Applications
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ME464-Sys Dyn & Ctrl Spring-2013 Dr. Shaukat Ali
Biological Systems: reaching an object (control of position)
Aircraft Autopilot (control of heading)
Room air-conditioning (Control of temperature)
Vehicles (direction control, speed control)
Control Systems Examples
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ME464-Sys Dyn & Ctrl Spring-2013 Dr. Shaukat Ali
Open-Loop Control System
This system utilizes an actuating device to control the process
directly without feeding back the output to the system.
Examples: Microwave oven, Ceiling fan, etc.
Conclusion:
Feeding back the output to the control system is then necessary
in a case where there are possibilities of changes in
the output.
Control Systems Classification
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ME464-Sys Dyn & Ctrl Spring-2013 Dr. Shaukat Ali
Closed-Loop Control System
This system utilizes a measurement of the output and feedback of
this to compare it with the desired response.
Feedback is a method of letting the input know what the output
is doing.
This means feedback can affect the way the control system
works.
Examples: Air conditioner (temperature control), Automobile
(steering control, speed control), etc
Control Systems Classification
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ME464-Sys Dyn & Ctrl Spring-2013 Dr. Shaukat Ali
A control system is said to be 'closed loop' if it includes
feedback.
A control system is said to be 'open loop' of it does not
contain feedback.
Control Systems Classification
ControllerProcess
orPlant
Feedback
ActuatorRef.Input
ActualOutput
Measured output
Error
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+ Actuatingsignal
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ME464-Sys Dyn & Ctrl Spring-2013 Dr. Shaukat Ali
Process or Plant: also called the controlled system is the body,
process, or
machine, of which a particular quantity or condition is to be
controlled.
Controller: or control device the component required to generate
the appropriate control
signal applied to the plant.
Reference input: An external signal applied to a control system
in order to
command a specified action of the plant.
Actual output: is that quantity or condition of the plant which
is controlled.
Control Systems Components
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ME464-Sys Dyn & Ctrl Spring-2013 Dr. Shaukat Ali
Control System Examples
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ME464-Sys Dyn & Ctrl Spring-2013 Dr. Shaukat Ali
Automobile Steering
Control System
Control System Example
Driver Automobile
Visual sensor
SteeringMechanism
Desireddirection
Actualdirection
Measured output
Error
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+ Actuatingsignal
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ME464-Sys Dyn & Ctrl Spring-2013 Dr. Shaukat Ali
Fluid Level Control System
Control System Example
Operator Fluid Tank
Visual sensor
ValveDesired
level
Actuallevel
Measured output
Error
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+ Actuatingsignal
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ME464-Sys Dyn & Ctrl Spring-2013 Dr. Shaukat Ali
Human Control System: reaching an object
Control System Example
BrainArm ,hand
Visual sensor
MusclesDesiredposition
Actualposition
Measured output
Error
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+ Actuatingsignal
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ME464-Sys Dyn & Ctrl Spring-2013 Dr. Shaukat Ali
Watts flyball Governer:
Control System Example
Flyballgovernor
Engine
Mechanical linkage
valveDesiredspeed
Actualspeed
Measured output
Error
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+ Actuatingsignal
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ME464-Sys Dyn & Ctrl Spring-2013 Dr. Shaukat Ali
Automobile Steering
Control System
Control System Example
Driver Automobile
Visual sensor
SteeringMechanism
Desireddirection
Actualdirection
Measured output
Error
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+ Actuatingsignal
What if there is no driver in the car?
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ME464-Sys Dyn & Ctrl Spring-2013 Dr. Shaukat Ali
Autopilot Control System:
Control System Example
Computer Airplane
GPS
Rudders, aileron, engine
Desiredheading
Actualheading
Measured output
Error
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+ Actuatingsignal
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ME464-Sys Dyn & Ctrl Spring-2013 Dr. Shaukat Ali
Robot control system
Control Systems Examples
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ME464-Sys Dyn & Ctrl Spring-2013 Dr. Shaukat Ali
Temperature control system
Control Systems Examples
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ME464-Sys Dyn & Ctrl Spring-2013 Dr. Shaukat Ali
Speed control system
Control Systems Examples
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ME464-Sys Dyn & Ctrl Spring-2013 Dr. Shaukat Ali
Multivariable Control
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ME464-Sys Dyn & Ctrl Spring-2013 Dr. Shaukat Ali
Coordinated Control System for a boiler-generator
Control Systems Examples
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ME464-Sys Dyn & Ctrl Spring-2013 Dr. Shaukat Ali
Control System Design
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ME464-Sys Dyn & Ctrl Spring-2013 Dr. Shaukat Ali
Control System Design Process
1. Establish the Control Goals
2. Identify the Control variables
3. Write the specifications
4. Establish the system configuration
5. Obtain a model of the process, the actuator and the
sensor
6. Describe a controller and select key parameters to be
adjusted
7. Optimize the parameters and analyze the performance
Control System Design
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ME464-Sys Dyn & Ctrl Spring-2013 Dr. Shaukat Ali
Design process:
Control goal: Design a system to regulate the blood sugar
concentration of a diabetic by controlled dispensing of
insulin.
Variable to be controlled: blood glucose concentration.
Control design specification: provide a blood glucose level that
closely approximates the glucose level of a healthy person.
Preliminary system configuration:
Design Example: Insulin Delivery Control System
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ME464-Sys Dyn & Ctrl Spring-2013 Dr. Shaukat Ali
Control Engineering
Control systems
Applications
Classification
Components of control systems
Examples of control systems
Design of control systems
Chapter 1: Review
