PLC based Traffic Light Control system with V2X Communication Simulation using SPaT/MAP messages

A PLC synchronized with OMNeT++ can simulate detailed V2X and I2V/V2I communication with virtualized traffic. The HIL test can be run in real-time. The PLC is responsible for providing traffic light state information with standardized SPaT/MAP messages for the virtual traffic. This HIL test demonstrates the PLC-based traffic light control's capabilities and the advantages of simulating communication. This way, the traffic light program is very flexible, and a mixed reality system is realized. A flexible traffic light program is a requirement in case of enormous testing of autonomous vehicles and their behavior to faulty traffic lights.

Sustainable Commuting

Hardware

Laboratory HW:

ACTROS VTC 3000 Traffic Controller

The lab owns two ACTROS road traffic controllers equipped with inductive loop detectors. The controllers are the product of Swarco Traffic Hungaria Ltd. This controller can be programmed in JAVA program language and is able to handle the complete language functionality. OCIT communication protocoll is supported by ACTROS. The controller is also used in BSc/MSc courses.

Siemens C840XS Traffic Controller

The smallest model of SITRAFFIC family with pedestrian signals, 4 signal  goups, and 6 detectors.
Important parameters:
- Standard: DIN VDE 0832 (prEN50278), RiLSA, EMC and Low-Voltage Directive.
- Processor: 32 bit Motorola 68340 CPU, Memory: 2 MB protected SRAM; Flash SIMS. Minimal memory: 5.5 MB. - Serial port (for DCF or GPS moduls).
- Central communication: BEFA12/15/16, CANTO, or OCIT.
- Signal checking: 2 channel fail-safe system.

Traffic Lights Controlled by PLCs

 The Laboratory has Siemens PLCs (S7-1200 and LOGO! 12/24 RC models). A small traffic control system was built based on the PLCs containing 3 LED signal heads and button for pedestrian crossing. Each PLC is responsible for the control of one signal head, furthermore the equipment S7-1200 receives the pedestrian requests for a green sign. The PLC 1200 checks the operation of the two LOGO!s. The described devices simulate a fixed time signal program with a green request opportunity for pedestrians.

Connecting SUMO with Unreal Engine 4 (UE4) through Simulink

In recent years, co-simulation became an exciting area in the industry as well as in the industry. The aim of co-simulation is creating synergies between different simulation software. In the following example the traffic simulator SUMO is connected to a visualization module built in Unreal Engine 4, through Simulink.

The Vehicle Dynamics Blockset of Matlab Simulink provides interface blocks to connect with scenes, created with UE4. SUMO cannot directly connect to Simulink, but it can be interfaced with Matlab through TraCI. To circumvent this limitation of Simulink, a set of embedded Matlab function blocks are created. These blocks initialize a predefined traffic simulation network and communicate with it. Relevant states (vehicle ID, position, velocity, and heading) are continuously read from SUMO and output to Simulink. The states of each individual vehicle are passed to 3D vehicle simulation blocks that can be directly visualized in UE4.

The simulation example is based on the models SmartCity module of the ZalaZone automotive proving ground. The accurate models of the test track are available in different file formats: https://github.com/BMEAutomatedDrive/ZalaZONE-automotive-proving-ground-virtual-simulation-models.