METHOD FOR RECOGNISING AN OBSTRUCTIVE SITUATION IN A MOTOR DRIVEN ELEMENT

A method for recognizing an obstructed situation of a traveling element. The method includes evaluating a variable containing information about the motor's rotational speed as the motor is driving the element. Starting from a current detection time point, the sequence of values of the variable determined at immediately preceding detection time points are observed. Change in behavior of the sequence of observed values of the variable with respect to one another over time are then compared with a value range of the variable that is indicative of the element being obstructed. A sufficient match between the value range of the variable and the sequence of observed values of the variable exists if at least three successive observed values of the variable fall within the variable value range. The element is determined to be obstructed upon the existence of a sufficient match. The variable includes the duration of motor time periods.