Integrated Safety and Traffic Control Systems in Multi-Level Underground Parking Garages: Design, Energy Optimization, and Virtual Validation in a PLC Architecture

The growing shortage of surface space in urban areas is forcing the construction of multi-level parking garages beneath shopping centers, which creates two critical challenges: the risk of toxic and explosive gases (CO, LPG) and energy-inefficient control of building ventilation. Traditional solutions rarely combine stepless ventilation control with metrologically reliable occupancy counting. An integrated parking management system (PMS) for a facility with 100 parking spaces based on a SIMATIC S7-1500 controller working in conjunction with distributed ET 200SP stations in a PROFINET network was proposed. Validation was performed using the Software-in-the-Loop (SIL) method in the S7-PLCSIM Advanced environment, using a linear congruential generator (LCG) for stochastic simulation of vehicle motion. Functional tests confirmed the correct operation of the entry/exit state machines, and the TWA algorithm implemented in block OB30 reproduced the results of the analytical model with full accuracy. The proposed architecture eliminates the measurement uncertainty and occupancy counter drift characteristic of differential methods, and the transfer of TWA calculations to a cyclic interrupt ensures compliance with the PN-EN 50545-1 standard, while significantly optimizing the energy consumption of jet ventilation.