METHOD AND ELECTRONIC DEVICE FOR COMPENSATION FOR THE DRIFT BEHAVIOR OF A PNEUMATIC ACTUATING ELEMENT DURING OPERATION

A method and an electronic device for compensation of the drift behavior during operation of a pneumatic actuating drive whose electropneumatic valve is operated in order to produce a control pressure in a closed control loop for position regulation of a switching element on the basis of a position regulator. A velocity profile v(t) of the switching element is recorded along the time axis during operation of the regulation, and at the same time, the opening cross-section profile A(t) of the fitting which is predetermined for the position regulator as a nominal value, is also recorded. The velocity profile v(t) and the corresponding opening cross-section profile A(t) are converted by elimination of the time to a velocity opening cross-section characteristic (v-A-characteristic). The v-A-characteristic is analyzed by pattern recognition for the presence of a braking profile which is characteristic of sealed closure, and before sealed closure, at least the last two measurement points in the braking profile are extrapolated to a point which is determined to be the opening point and is actually not zero.