Control System Notes on Static Error Coefficients STATIC ERROR COEFFICIENT
there are two types of error coefficient.
1.) static error coefficient
2.) Dynamic error coefficient
1.) Static error coefficient:- the ability of the system to reduce or eliminate the steady state error is static error coefficient
they are of 3 different types.
1.) position error coefficient:- related to the output of the system. it is denoted by kp.
2.) velocity error coefficient:- related to the rate of change of output of the system. it is denoted by kv.
3.)acceleration error coefficient:- related to the rate of change of output. it denoted by ka.
|Step input||Ramp input||Parabolic input|
|Type 0 system||1/(1+Kp)||∞||∞|
|Type 1 system||0||1/Kv||∞|
|Type 2 system||0||0||1/Ka|
feature of static error are as follows
1.) higher error coefficient increase the steady state performance of the system
2.) cannot be used to calculate the error of unstable system
3.) do not indicate the correct manner in which the error changes with time
4.) it is difficult to stabilized the system
DYNAMIC ERROR COEFFICIENT
use to express dynamic error
provides error signal as function of time
used for determining any type of input
the dynamic error coefficient provides a simple way of estimating error signal to arbitrary inputs and the steady sate error without solving the system differential equation.