Interfacing a Traffic Light Controller with SUMO for Hardware-in-the-Loop Testing

Abstract

In preparation to deploy novel traffic control approaches into the field, the actual traffic light controllers (TLCs) need to be programmed and tested in advance. In this contribution, we present our approach to using SUMO as a hardware-in-the-loop testing tool for a Siemens sX TLC. First, we model a SUMO scenario that replicates the specific constraints of the junction that shall be controlled by the TLC. This encompasses in particular the junction geometry, signal groups and detectors as given by real-world conditions. Secondly, we set up a simulation in SUMO that emulates traffic flows according to the test scenarios at hand. This SUMO simulation then serves both as the source for inputs to the TLC and as well as the receiver of the actual TLCs traffic signal outputs. The following loop will be executed for the duration of the test: 1. The detector information of the detectors in the SUMO simulation is gathered. 2. The detector information is sent through an XFER interface via an ESCoS road side unit (RSU) to the TLC. 3. The corresponding internal detector values of the TLC are set accordingly. 4. The control logic of the TLC is executed based on its current state (e.g. current phase, phase duration and detector values). 5. The resulting signal states are sent back through the XFER interface via the ESCoS RSU to the SUMO simulation. 6. The signal states in the SUMO simulation are updated accordingly. 7. SUMO simulates the traffic participants behavior with the given signal states. We present our test setup in the ITS Lab of DLRs Institute of Transportation Systems as well as the initial results from a test case, utilizing some of the SUMO tools for traffic evaluation and visualization.