Linear Actuator, Method for Controlling the Same, and Head Lamp Assembly Comprising the Same

A method for controlling an actuator in which a nut including a magnet moves forward or backward by a motor and a sensor detects a position of the magnet,

• the method comprising;
• a) aligning a boundary line between the first pole and the second pole with a center of the sensor unit,
• wherein, step a) comprises:
• a-1) if the sensor unit senses the first pole when the nut part is moved forward, a first motion in which a forward movement of the nut part is stopped and moving the nut part backward;
• and
• a-2) if the sensor unit senses the second pole after the first motion, a second motion in which the movement of the nut part is stopped and moving the nut part forward.

A head lamp assembly, comprising:

• a motor;
• a lead screw rotating by coupling to the motor and rotating;
• a nut part moving forward or backward by coupling to the lead screw;
• a magnet coupled to the nut part;
• a sensor unit configured to sense a change amount of magnetic flux depending on a position of the magnet;
• a control unit controlling the motor;
• and
• a head lamp coupled to the nut part;
• wherein the magnet comprises a first pole and a second pole arranged in order in the movement direction of the nut part,
• wherein, if the sensor unit senses the first pole when the nut part is moved forward, the control unit performs a first motion in which a forward movement of the nut part is stopped and moves the nut part backward, and if the sensor unit senses the second pole after the first motion, the control unit performs a second motion in which the movement of the nut part is stopped and moves the nut part forward.