Comfortable Automated Emergency Brake for Urban Traffic Light Based on DSRC and On-Board Sensors

In this work, Dedicated Short Range Communication (DSRC) capabilities combined with classical autonomous vehicles’ on-board sensors (Camera) are used to trigger a Comfortable Emergency Brake (CEB) for urban traffic light intersection scenario. The system is designed to achieve CEB in two phases, the Automated Comfortable Brake (ACB) and the full stop Automated Emergency Brake (AEB). The ACB is triggered first based on the content of the Signal Phase and Timing (SPaT) / Map data (MAP) messages received from the Road Side Unit (RSU) at larger distances. And, once the traffic light becomes in the detection field of view of the camera, the output of the Camera-based Traffic Light Detection (TLD) and recognition software is fused with the SPaT/MAP content to decide on triggering the full stop AEB. In the automated vehicle, the current traffic light color and duration received in the SPaT message is parsed; and compared with the TLD output for color matching. The TLD output is used to confirm the correctness of the traffic light status received in SPaT, and used as a second layer of validation before applying the final brake. The system has been experimented and evaluated using urban road data collected in day light conditions. The overall performance showed an early reduced speed is accomplished via ACB, which helps achieving a smooth transition to a final stop AEB.