In order to allow the drivers to know clearly where the location of parking space is, we installed a panel at the entrance, allowing the drivers to explicitly ask for parking lattices. Hence, it not only saves a lot of time for the drivers, but also prevents traffic congestion in the crowded parking lot; we can improve the parking problems in today's society. To make the ultrasound signal transmitted to the roof of the car, we set it in the code distance lest there should be other disturbing objects to ultrasonic signals.