Event-triggered prescribed-time distributed formation control of marine surface vessels with prescribed performance

Abstract

In this paper, an event-triggered prescribed-time distributed formation control method is designed for marine surface vessels with prescribed-time prescribed performance subject to compound uncertainties. Firstly, we introduce variable substitutions to simplify the mathematical model of marine surface vessels. Then, a prescribed-time extended state observer is constructed to estimate unmeasured velocities and compound uncertainties at a prescribed-time. Meanwhile, a novel prescribed-time performance function with an error transformation is designed to impose constraints on formation errors. Subsequently, we design an event-triggered control mechanism taking account of error constraints, which reduces the operating frequency of actuators without weakening system transient performance. Based on the designed extended state observer, performance function and event-triggered control mechanism, a prescribed-time distributed formation control law is developed for marine surface vessels with distinguished convergence performance, good transient performance, and low actuator losses. At last, simulations are conducted to illustrate the advantages and application prospects of the designed approach. The proposed method has several notable characteristics compared with most existing strategies: 1) it guarantees the prescribed-time convergence of the formation errors; 2) it achieves prescribed-time error constraints by using the designed performance function; 3) it actualizes the quantitative balance between error constraints and the operating frequency of actuators via the proposed event-triggered control mechanism, which can avoid the excessive wear on actuators.