Abstract: This project work presents the study and design of PLC based Multilevel Automatic Car Parking System. Multilevel car parking is the most efficient way of parking as by using this arrangement we can park most number of vehicles in least possible area. In this project we have made a prototype model of such system. The prototype model is made for accommodating nine cars at a time. Availability of space is detected by proximity sensors installed in each slot of each floor. A elevator is used to lift the car and park it at respective free slot. A PLC is used for checking vacancies and the control of the elevator. The proximity sensors installed in the system give PLC information regarding the free space as well as when the elevator has to stop depending on where the car is to be parked. This system automates the entire process of parking which reduces human error and makes best use of the available space, which in-turn results in highest security. Due to these advantages, this system can be used in societies, airports, railway stations or any other place where crowding of vehicles is observed.

Keywords: PLC (Programmable Logic Controller), Proximity sensors, LLD (Ladder Logic Diagram), Prototype Model, HMI (Human Machine Interface).