Vehicle door locking and unlocking vehicle-mounted device, vehicle including vehicle-mounted device, and vehicle door locking and unlocking system including vehicle-mounted device

A vehicle door locking and unlocking vehicle-mounted device comprising:

• communication means for receiving a lock command or an unlock command from a user terminal directly or through a server;
• and
• at least two internal relay connected to wiring installed in a vehicle between a door key switch installed in the vehicle and a door lock actuator installed in the vehicle, wherein
• the internal relay includes a first internal relay and a second internal relay independently connected to ground or a power supply, the first internal relay and the second internal relay controlling at least one external relay to respectively control locking and unlocking of a door installed in the vehicle,
• when the lock command is received, a state of the internal relay changes for a predetermined time to drive the door lock actuator in a first direction to lock the door and when the unlock command is received, a state of the internal relay changes for a predetermined time to drive the door lock actuator in a second direction to unlock the door.