Fixed-Time Consensus Control of General Dynamical Multiagent Systems: Methodologies and Applications

Fixed-time consensus control offers an explicit upper bound on the settling time that is independent of initial conditions, making it particularly valuable for time-critical applications. This survey reviews recent advances in this field, with emphasis on two primary directions: extending fixed-time consensus to broader classes of dynamical multiagent systems, and designing engineered protocols that enhance practical applicability. First, we examine fixed-time consensus results for general dynamical systems, including well-established methods for general linear multiagent systems and emerging approaches for specific classes of nonlinear systems, where a unified theoretical framework remains elusive. Notably, conventional fixed-time consensus protocols often induce excessively large initial control inputs and lack fully distributed settling-time estimation, motivating the development of protocols with engineered features. Second, we review recent advances in specialized consensus protocols that address these practical challenges, focusing primarily on finite-time consensus protocols with bounded control inputs and fully distributed fixed-time consensus protocols, while also covering recent efforts on event-triggered implementations and secure strategies under cyberthreats. The practical utility of these protocols is demonstrated through two case studies: position synchronization of brushless dc motor systems and frequency regulation in islanded microgrids. Finally, key challenges and promising directions for future research are discussed.