Warning System for Pedestrian (WSP)

In case of ITS-G5 communication technologies a use case could include no Roadside Units as vehicles are communicating via ETSI ITS-G5. There are two instances of the On-Board Unit component. One is detecting the pedestrian and transmitting the information to the other one which trajectory possibly collides with the Vulnerable Road User. The communication consists of a DENM message with cause code people on the road. The receiving On-Board Unit calculates if there is a possible collision with the Vulnerable Road User. If so the On-Board Unit informs the driver via the cars Human Machine Interface. The On-Board Unit expects a reaction from the driver such as slow down, take a turn or acknowledge the message. If after a time-out no reaction is detected, the safety protocol of the On-Board Unit is activated. In the case of an unsignalized pedestrian crossing (zebra but no traffic lights) a Roadside Unit with Vulnerable Road User detection capabilities can be installed. The Roadside Unit will monitor the trajectories of the Vulnerable Road User with its detection system. The cars indicate their presence with broadcasted CAM messages. The Roadside Unit calculates the trajectories of both car and Vulnerable Road User. In case of a conflict the communication flow uses a DENM message indicating Vulnerable Road User on the road. In the case of a signalized crossing with a Roadside Unit with C-ITS capabilities, the Roadside Unit controlling the traffic lights sends a SPAT or SPATEM message. In the service the information only goes from the Traffic Light Controller to the car. The On-Board Unit uses the information in the SPAT message to decide if the Vulnerable Road User has priority because of the green light. In that case no warning is issued through the Human Machine Interface because the driver is already informed via the status of the traffic lights on its own lane. If the Vulnerable Road User violates the lights, then a warning is issued. If the driver does not react, the safety protocol is activated. The detection of the Vulnerable Road User can come from another On-Board Unit that sends a DENM message. The uses case of a signalized crossing with a Roadside Unit Traffic Light Controller and a Roadside Unit with Vulnerable Road User detection is a combination of the previous two use cases. Here we consider the case where the Traffic Light Controller does not use ITS-G5 communication. The Roadside Unit with Vulnerable Road User detection receives the traffic light status via a wired connection. The vehicle On-Board Unit sends CAM messages to inform about its trajectory that are interpreted by the Roadside Unit. The Roadside Unit sends a DENM message if there is a conflict in the trajectories and the Vulnerable Road User does not have a green light. The On-Board Unit combines the DENM info with its own information to decide if it is necessary to warn the driver through the Human Machine Interface. If so and the driver does not react, the safety protocol is activated.

In case of cellular communication technologies with the On-Board Unit the drive activates the service at his service provider. The service provider’s data center allocates a distributed data center local to the vehicles position that will monitor the vehicle. If the vehicles move away from this distributed data center another distributed data center is allocated. The distributed data center receives frequent updates of the vehicle position. This position is send to Roadside Unite with Vulnerable Road User detection that are nearby. The Roadside Unit combines the traffic light status with the detection of Vulnerable Road Users and the vehicle position. If the light is red for the Vulnerable Road User and there is a possible conflict with the vehicle trajectory, the Roadside Unit sends a message to the distributed data center. The distributed data center sends a message to the On-Board Unit via the cellular transport network. Finally, the On-Board Unit receives the message that a Vulnerable Road User is detected on his trajectory. The On-Board Unit warns the driver via the Human Machine Interface. If no reaction is detected, the On-Board Unit activates the safety procedure.