Jaspreet System Type and Steady State errors from Bode Plots Flashcards
What is the type number?
It is equal to the number of poles at the origin
What is the equation for the Position error constant and when does it occur?
It occurs for a type 0 system and is Lim(s->0) G(s)
What is the equation for the velocity error constant and when does it occur?
It occurs for a type 1 system and is Lim(s->0) s * G(s)
What is the equation for the acceleration error constant and when does it occur?
It occurs for a type 2 system and is lim(s->0) s^2 * G(s)
What is the relative degree?
It is denoted by K and is the number of poles - the number of zeros:
n-m
What do the low frequency characteristics of a system depend on?
The type number. The gradient will be the type number * -20db. The phase angle will be type number * -90
What do high frequency characteristics depend on?
The relative degree of the system K.
Gradient = k * -20
Phase = k * -90
How can we use the Bode Plot to determine steady state error?
By projecting the low frequency asymptote which is a straight line until it hits the 0db Gain line.
Kp = G(0)
Kv = wr - the point where the line crosses the frequency axis
Ka = wa^2
What is the slope of low frequency asymptote for a type 1 or type 2 system?
For type 1 = -20
For type 2 = -40