Control Systems Flashcards
(28 cards)
Draw a response curve of a control system
Define the transient response of a response curve
The output of the control system before reaching steady state.
Define the steady state response
The final value of the response curve
What is a Transfer Function
The ratio of the Laplace Transform of the output to the input IOT generate a simple linear function to describe the dynamics of the system.
Note: Laplace transforms the domain of the function (from t to s) IOT to make it linear. This makes it easier to work with before being transformed back to time domain.
What constitues linearity?
Superposition: The sum of the inputs is the sum of the outputs
Homogeneity: ax = xa
What is Steady State Error
the difference in the desired output and the steady state response
What is Rise Time
The time it takes for teh system to reach from 10% o 90% of its steady state value
What is the “natural response”
aka the transient response
Determined only by the system, not the input
To be useful:
Steady state or;
Oscillate
(not exponential)
Define Step Response
Response to a step input (discreet steps).
It is used to test the system’s behaviour in a steady environment.
What is the error band?
The allowable range of the steady state value
Instability
The system output grows exponentially
Define overshoot
The maximum amount the signal exceeds the steady state value
Define “Settling Time”
the time it takes for the system to reach and stay within 2% of its steady state value
Define “Pole”
Causes TF to go to infinity
Define “Zero”
a value that makes the TF go to zero
Draw a fictional pole map with examples of
Exponential decay
Exponential growth
Exponential alternating approaching infinity
Exponential alternating approaching 0
Slide 34
What are the conditions for a control system to be stable?
Poles are all negative
Under what conditions is a control system marginally stable?
Zero value pole(s)
Under what conditions are control systems unstable?
One or more positive holes
What is a first order system?
Draw a first order block diagram.
Single pole system. Slide 37
In a first order system, what is the constant ‘a’ representing?
The initial slope of the system.
What is a Second Order System? Draw the block diagram.
Two poles
has a binomial equation in the denominator and a constant in the numerator.
Slide 40
Define “Damping Ratio”
Compares the exponential decay to the natural decay, representing the amount of oscillation in the transiet response.
Define the “Natural Frequency”
Frequency of the system without damping.
