The disclosure relates to a method for controlling a wind turbine including a wind rotor shaft, a rotary encoder for measuring the azimuth angle of the wind rotor shaft, wherein the wind turbine further includes at least one impulse generating device including at least one first part and at least one second part, wherein the at least one first part is rotating with the wind rotor shaft and the least one second part is disposed stationary with respect to the wind rotor shaft such that the at least one first part moves by the at least one second part; wherein the method includes: encoding the azimuth angle of the wind rotor shaft by the rotary encoder into a rotation value; generating an impulse when one of the at least one first part moves by one of the at least one second part of the impulse generating device; comparing the rotation value at the time of a detected impulse with a reference value.