If you need to count the vehicles parked in the parking lot and display them on the remaining parking space display screen in real time, you can realize this function through the parking space guidance system. However, if you don't have high requirements and limited budget, you just want to realize this function, the location guidance system may be more suitable for you. The parking space guidance system is different from the location guidance. The parking space guidance system adopts ultrasonic technology or video detection technology, which can monitor the status of specific parking spaces in real time. It has a high degree of automation and is accurate and real-time, but its cost is also high. It is generally used in large parking lots and is not suitable for ordinary parking lots with low budget. The cost of the location parking space guidance system is much lower, and the principle is simple and easy to implement. It can use an ordinary vehicle detector. It needs to bury a ground sensing coil at each inlet and outlet and install a vehicle detector. When the vehicle enters and exits, the controller will add 1 and subtract 1 according to the situation detected by the detector and make statistical calculation, Publish the calculation results to the remaining parking space display screen, so that users can clearly know the current parking space status of the parking lot, such as the number of parked vehicles, the remaining parking spaces, etc. The location guidance system can operate independently or connect with the parking lot system server. As long as the vehicles enter and leave, the system will automatically count and transmit the data to the parking space display screen. The implementation principle is simple, the reliability is high and the cost is low, which can meet the display needs of the remaining parking spaces in the general parking lot. However, its disadvantage is that it can not accurately the specific parking space, can not achieve parking space guidance, and can only be regional guidance, so it can only be called Regional guidance system.