Parking Guidance Systems are primarily designed for large and medium-sized underground parking facilities, widely used in public parking areas such as office buildings, train stations, and shopping malls. The main working principle involves emitting ultrasonic waves from above downwards using ultrasonic sensors, detecting the reflected waves from the car roofs and ground, thereby accurately determining whether each parking space is occupied. The information on the parking status of each space is then transmitted to the control computer via network lines. The computer processes this data through software and sends guidance signals to the indicator, which guides drivers to find vacant spaces quickly.