Hierarchical Event-Triggered Platoon Control for Heterogeneous Connected Vehicles Subject to Actuator Uncertainties and Non-Zero Inputs

The emerging vehicle-to-vehicle communication technique enables vehicle platoon control, which greatly increases road throughput and travel efficiency. For cybernetically connected vehicles (CVs) with dynamics heterogeneities subject to actuator uncertainties, a dynamic event-triggered platoon control protocol is proposed in this paper to significantly reduce communication overheads. By considering the platoon problem of CVs as an output tracking consensus problem of heterogeneous multi-agent systems (MASs), a hierarchical control framework composed of an upper-level interactive event-triggered observer layer and a lower-level local tracking controller layer is established. Within the proposed framework, considering a virtual dynamic leader with non-zero inputs and external disturbances, a distributed observer is first designed for each following vehicle to observe the leader in an event-triggered manner. An internal dynamic variable is introduced to construct the dynamic triggering law, which not only relaxes the requirement on continuous state transmission in triggering detection but also benefits the exclusion of the Zeno behavior. Then, the solutions of a set of regulator equations associated with the proposed observer and the observer itself are integrated into the local tracking controller design to guarantee the tracking ability of each follower agent to its own observer. As thus, an event-triggered platoon control mechanism of heterogeneous CVs is proposed. Simulations and experiments on unmanned ground vehicles (UGVs) are conducted, which validate the effectiveness of the proposed platoon control method.