Automated Car Parking System Using PLC Programming
- 〡
- 〡 by WUPAMBO
Introduction to PLC-Based Car Parking Systems
In industrial automation, Programmable Logic Controllers (PLCs) play a crucial role in managing real-time control operations. A PLC-based car parking system automates vehicle entry and exit, improving space utilization and reducing human error. Such systems are widely implemented in smart buildings, malls, and industrial complexes to enhance operational efficiency.
System Overview and Operational Logic
The car parking system consists of two garages, each capable of accommodating five vehicles. The PLC continuously monitors the number of cars entering and leaving through sensors placed at entry and exit points. When a car enters, an up counter adds one to the total; when a car exits, a down counter subtracts one. This logic ensures accurate, real-time occupancy tracking.
Input and Output Configuration
The system integrates several digital inputs and outputs:
-
Entry Sensors: Detect incoming vehicles.
-
Exit Sensors: Detect departing vehicles.
-
Indicator Lamps: Show garage status (available, full, or closed).
-
Control Gates: Operate automatically based on parking availability.
Each signal is processed by the PLC, which executes control actions according to programmed rungs and interlocking logic.
Programming Logic and Rung Description
The control logic is written using RSLogix 500.
-
Rung 000: Master Start/Stop for overall system activation.
-
Rung 001: Handles entry authorization via the entry sensor.
-
Rungs 002–003: Count vehicles entering Garage 1; activate the “Garage Full” lamp when capacity reaches five.
-
Rungs 004–005: Trigger exit logic to decrement the counter.
-
Rungs 006–010: Repeat similar logic for Garage 2, ensuring load balancing.
One-shot pulses are used to ensure each vehicle triggers only a single count event, preventing miscounts from sensor bounce.
Automation Advantages and Industrial Relevance
PLC-controlled parking systems demonstrate how control systems and industrial automation technologies can improve safety, accuracy, and operational consistency. Compared to manual parking management, PLC logic eliminates human dependency, allowing faster throughput and minimal congestion. This design can also integrate with SCADA or DCS systems for centralized monitoring.
Expert Insights and Practical Applications
In my experience working with Allen-Bradley and Siemens PLCs, parking automation projects are valuable training models for mastering counter functions, interlocking logic, and I/O mapping. Such systems are often used in educational labs to demonstrate real-time automation control and sensor feedback systems.
Conclusion
This PLC-based car parking example provides an accessible way to understand counter logic and system interlocking in industrial environments. While simplified, it mirrors the core principles used in commercial automation solutions. Engineers can extend this model by integrating HMI panels, Ethernet communication, or smart sensors for more advanced control.
Application Scenario
This logic can be applied in:
-
Multi-story or underground parking systems.
-
Automated factory vehicle bays.
-
Smart building management systems integrating IoT modules for predictive occupancy analytics.
- Posted in:
- Allen-Bradley
- control systems
- counter logic
- factory automation
- PLC programming
- RSLogix 500
- smart parking
