Feedback Flashcards
Consists of subsystems and processes assembled for the purpose of obtaining a desired output with desired performance, given a specified input.
Control System
Two major measures of performance
Transient response
Steady-state error
Is the process of causing a system variable to conform to some desired value, called a reference value and usually defined in terms of the system’s step response.
Control
Is the process of measuring the controlled variable and using that information to influence the value controlled variable.
Feedback
Is truly a multi-disciplinary study that cuts across boundaries of many disciplines
Control Theory
Is the cornerstone of control theory
Math
Is also an important building block, though mostly from the aspect of signals and systems, and less from circuits.
Electrical Engineering
Is likewise an important fundamental, chiefly from the standpoint of dynamic system behavior.
Mechanical Engineering
Four primary reasons we build control systems
Power Amplification
Remote Control
Convenience input form
Compensation for disturbances
Who invented the water clock
Ktesibios
When did the Greeks began engineering feedback systems
300 B.C.
Operated by having water trickle into a measuring container at a constant rate
Water Clock
Applied liquid level control to an oil lamp
Philon
Who invented the safety valve?
Denis Papin
When did regulation of steam pressure began?
1681
Who invented a purely mechanical temperature control system for hatching eggs?
Cornelis Drebbel
Applied speed control to a windmill
Edmund Lee (1745)
Improved the windmill idea by dividing the windmill sail into movable louvers
William Cubitt (1809)
Invented the flyball generator to control the speed of steam engines
James Watt
Published the stability criterion for a third-order system based on the coefficients of the differential equation.
James Clark Maxwell
Was able to extend the stability criterion to fifth-order systems
Edward John Routh (1874)
Used a gyro to sense a ship’s motion and applying power generated by the ship’s hydraulic system to move the ship’s saloon to keep it stable
Henry Bessemer (1874)
Installed an automatic steering system that used the elements of compensation and adaptive control to improve performance
Sperry Gyroscope Company (1922)
a graphical technique to plot the roots of a characteristic equation of a feedback system whose parameters changed over a particular range of value
Root Locus
