Pitch control system (1) for at least one rotor blade (17) for a wind turbine comprising a nacelle (16), as well as a hub (15) both place on the top of a tower (18) and at least one rotor blade (17). The system comprises at least one electrical pitch drive system (3) each drive system (3) is connected to a rotor blade (17) and an electrical pitch motor (2). The electrical pitch drive system(s) (3) is/are adapted to communicate with units comprising the motor(s) (2) for pitching the rotor blade (17) it is attached to and in accordance with inputs registered from a first sensor and a second sensor (20). Each electrical pitch drive system (3) comprises a gyroscope (22) adapted to register an angle value of the longitudinal axis of the rotor blade (17) with respect to the gravity. A processor is adapted to calculate the position of the rotor blade (17) based on said values.