A method includes using a Hall angular displacement sensor to detect a magnetic field strength generated by a magnet disposed on a first end of a rotating shaft of a motor assembly of a gimbal. The sensor is disposed on a side of an electrical connecting device in a first rotating member of the gimbal that faces away from the magnet. The method further includes determining a rotational angle of a rotor of the motor assembly with respect to a stator of the motor assembly based on the magnetic field strength. The stator is coupled to the first rotating member. The rotor is coupled to a second rotating member of the gimbal and disposed on a second end of the rotating shaft. The method also includes determining a positional relationship between the first rotating member and the second rotating member based on the rotational angle.