Vehicle with rear occupant alert function and method of controlling the same

A method of controlling a vehicle, comprising:

• transmitting and receiving an ultrasonic signal to detect a presence or absence of an occupant inside the vehicle based on the ultrasonic signal;
• detecting an opening and closing state of a window including at least one of an upper window or a side window provided in the vehicle;
• and
• changing a preset level based on the opening and closing state, and comparing an intensity of the ultrasonic signal with the changed preset level to determine the presence of the occupant.

A non-transitory computer readable medium containing program instructions executed by a processor, the computer readable medium comprising:

• program instructions that transmit and receive an ultrasonic signal to detect a presence or absence of an occupant inside the vehicle based on the ultrasonic signal;
• program instructions that detect an opening and closing state of a window including at least one of an upper window or a side window provided in the vehicle;
• and
• program instructions that change a preset level based on the opening and closing state, and comparing an intensity of the ultrasonic signal with the changed preset level to determine the presence of the occupant.