Vehicle milestones for communication and platooning reached
MAVEN has completed vehicle automation developments, which allow the reception of Signal Phase and Timing (SPaT) messages from the infrastructure. The vehicle automation takes the desired speed sent by the Road Side Unit (RSU) for the upcoming traffic light into account when planning the correct behavior. As the MAVEN vehicle is longitudinally and laterally automated at the end, the vehicle reaches the green light fluently or comes to a smooth stop when passing at green is not possible.
For platooning a set of four state machineshas been developed. These state machines have been implemented in the vehicle automation to proof if the MAVEN urban platooning concept is working as desired. The image shows the state machines and the related behavior of an automated vehicle when reaching another automated vehicle able to form a platoon on the road. The working principle is illustrated in the figure below:
While driving, the cooperative ego vehicle on the left receives information about a cooperative vehicle in front which is also able to form a platoon (1). This information includes position, velocity, acceleration and also planned behavior on the upcoming intersection (turning/going straight). After processing this data in the platooning logic, the ego vehicle decides to form a platoon (2). Now it communicates this to the vehicle ahead, which receives this information, accepts and provides detailed trajectory information to the follower. Hence, the ego vehicle adapts its velocity in order to close the gap (3). When the gap is closed, the initialization is done and the vehicles follow each other in a platoon (4). The following vehicle is always in charge of choosing an appropriate distance. If the follower does not trust the leader, or recognizes any other thread, it can immediately stop platooning.