Event-Triggered Broadcasting for Formation Control with Collision Avoidance

This paper addresses the problem of multi-agent formation control and intermittent broadcasting with reduced sensor and communication requirements while maintaining connectivity, avoiding collisions, staying within a desired error tolerance, and maintaining stability. The Broadcast Period Update Algorithm calculates the time between inter-agent state broadcasts in which the state estimation will remain below a desired error threshold and then triggers a broadcast based on this threshold. Closed-loop stability is shown for each domain, and invariance is shown for the overall system by modeling the system as a switched system and using LaSalle’s Invariance Principle. An illustrative example shows that the novel, event-triggered communication method increases the broadcast rate from 0.0068s to 0.32s, quickly exits the inter-agent safety zone, converges in state estimation and tracking, and reduces large commands required. The new method outperforms comparison methods in simple examples in which the desired formation is constant or changes. However, in the more challenging case of an immediate disturbance, the novel method is temporarily outperformed by a constant, frequent broadcasting update, motivating an upper limit in broadcasting period in strenuous, disturbance-filled environments.