A method for controlling a surgical instrument comprising； measuring a current draw of a motor coupled to a drive assembly for actuating an end effector of the surgical instrument to obtain a plurality of samples of the current draw, calculating a plurality of rate of change values based on the plurality of samples of the current draw, determining whether operation of the motor reached a mechanical limit based on a portion of the plurality of rate of change values being within a first range of rate of change values and determining whether operation of the motor is stable based on a portion of the plurality of rate of change values being within a second range of rate of change values.
