A method for the delay-minimized detection of an auxiliary control variable for a system comprising a control system and a controller, whereby an output variable is detected at the end of the control system, whereby a disturbance variable is active in the control system, characterized in that a state variable is detected in the control system at a place before the point of action of the disturbance variable, whereby the auxiliary control variable is calculated from the state variable that has been weighted with a constant kx and from an estimation error, whereby the estimation error is calculated from a comparison between the detected output variable and the integrated auxiliary control variable.