System type

The system type describes the number of free integrators in control engineering . For example, if you consider the transfer function :

${\displaystyle H(s)={\frac {(s+1)}{s\cdot (s+2)\cdot (s+3)}}}$

one has exactly one free s in the denominator of the transfer function. In control engineering, an attempt is made to make a statement about the closed control loop from the system type of the open control loop with regard to the signals that a controller with the overall transfer function to be examined can just follow, i.e. reduce the error.

A system type of 0 regulates a constant control error with a step function as a signal. A system type of 1 can reduce control errors with step functions to 0, but has constant control errors with a ramp. A system type of 2 can reduce control errors for ramps to 0.