REAR OCCUPANT ALERT DEVICE AND METHOD THEREFOR

A rear occupant alert device according to an embodiment comprises a first object detection unit; a second object detection unit; and a control unit configured to control operations of the first and second object detection units, wherein the first object detection unit includes a passive infrared sensor (PIR) sensor, wherein the second object detection unit includes a radar module, and the control unit is configured to control a movement of an object inside a vehicle through the first object detection unit, and to control a movement of an object through the second object detection unit when the movement of the object is not detected through the first object detection unit.