CPE 043

Question 1

Control System examples

Answer 1

Man-made, Natural, Nonphysical

Question 2

sample of Man-made control system

Answer 2

rockets fire, space shuttle, cooling water, self-guided vehicle

Question 3

sample of Natural control system

Answer 3

blood sugar level, adrenaline rush

Question 4

sample of Nonphysical control system

Answer 4

student’s study time and student performance

Question 5

Purpose of Control Systems

Answer 5

(1) Power amplification (ex. rotating a huge radar antenna by a small knob)
(2) Remote control (ex. using robots in radioactive areas)
(3) Convenience of input form (ex. An aircon set to a temperature level produces cool air)
(4) Compensation for disturbances (ex. a wind or noise signal that passes through
an antenna is corrected by repositioning the antenna)

Question 6

Example of Liquid-Level Control (300BC)

Answer 6

water clock by Ktesibios

oil lamp of Philon (figure 1) of Byzantium

Question 7

What are the history of control system

Answer 7

*Liquid-Level Control (300BC)
*Steam Pressure and Temperature Controls (1681)
*Speed Control (1745)
*Stability, Stabilization and Steering (19th Century)
*20th Century Developments
*Contemporary Applications

Question 8

Example of Steam Pressure and Temperature Controls (1681)

Answer 8

safety valve by Denis Papin
emperature control by Cornelis Drebel

Question 9

Example of Speed Control (1745)

Answer 9

windmill by Edmund Lee and William Cubitt

flyball speed governor by James Watt

Question 10

Example of Stability, Stabilization and Steering (19th Century)

Answer 10

the differential equation for the stability of motion by Maxwell, Routh and Lyapunov

Steering and stabilization of ships by Henry Bessemer

Question 11

Example of 20th Century Developments

Answer 11

automatic steering of ships that led to what we call today proportional-plus-integral-plusderivative
(PID) by Nicholas Minorsky

Linear control systems analysis and control theory by Bode, Nyquist and Evans

Question 12

Example of Contemporary Applications

Answer 12

Finishing mills, X-ray measures, digital computer, reaction control system, etc.

Question 13

System Configurations

Answer 13

*Open-Loop Systems
*Closed-Loop (Feedback Control) Systems
*Computer-Controlled Systems

Question 14

___________ convert the input to the form which the controller uses

Answer 14

Input transducer

Question 15

The ________drives a process or a plant

Answer 15

controller

Question 16

The _______ can be called controlled variable.

Answer 16

output

Question 17

The ____ can be
called reference.

Answer 17

Input

Question 18

_____________ cannot compensate for any disturbances that add
to the controller’s driving signal (Disturbance 1) and only depends on the input.

Answer 18

Open-Loop Systems

Question 19

The ______________ measure the output and convert
it to the form used by the controller.

Answer 19

output transducer or sensor

Question 20

___________ compensate for disturbances thus having a greater
accuracy than open loop system. A trade off would be its cost and complexity.

Answer 20

Closed-Loop (Feedback Control) Systems

Question 21

The controller (or compensator) is a digital computer.

Adjustments of the compensator can be made by changing the software rather than the
hardware

Answer 21

Computer-Controlled Systems

Question 22

Analysis and Design Objectives

Answer 22

*Dynamic control system
*Transient response (1st Objective)
*Steady-State Response (2nd Objective)
*Stability (3rd Objective)

Question 23

___________ response of a system on the way the system dissipates or acquire
energy. In linear differential equations, it is called ____________.

Answer 23

Natural response, homogenous

Question 24

_____________ response of a system depending on the input. In linear
differential equations, it is called ___________.

Answer 24

Forced Response, particular solution

Question 25

_________ Upon reaching steady state, the natural response can go to zero or oscillate; or continue to
increase (which is _______). Thus, is required otherwise it would damage the system.

Answer 25

Stability (3rd Objective), unstable

Question 26

_______ is usually used to place initial energy to the system and check the transient response.

Answer 26

Impulse input

Question 27

_________ is used to compensate parameters shift due to external factors. (ex. due to temperature, pressure, etc.)

Answer 27

Sensitivity analysis

Question 28

Explain in your own words how a water clock and oil lamp of Philon works.

Answer 28

Water Clock by Ktesibios: Ktesibios’s water clock, or clepsydra, used a float in a container that filled with water at a steady rate. The float was connected to a pointer that indicated the time on a scale, improving the accuracy of time measurement.

Oil Lamp by Philon: Philon’s oil lamp measured time by the steady consumption of oil. As the oil burned at a consistent rate, the level of oil decreased, and this decrease was used to indicate the passage of time.

Question 29

Differentiate open-loop systems and close-loop systems.

Answer 29

An open-loop system operates without feedback.

A closed-loop system, also known as a feedback control system, uses feedback to compare the output with the desired input (reference) and makes adjustments to achieve the desired result.

Question 30

The Design Process

Answer 30

Step 1: Transform requirements into a physical system
Step 2: Draw a functional diagram
Step 3: Create a schematic
Step 4: Develop a mathematical model (Block Diagram)
Step 5: Reduce the block diagram
Step 6: Analyze and design