Finite-Time-Prescribed Performance-Based Platoon Formation Control for Unmanned Surface Vehicles Using Event-Triggered Extended State Observer
Wei Wang, Qihe Shan, Tieshan Li, C. L. Philip Chen, Yang Wang
Abstract
This article investigates the finite-time-prescribed performance-based (FTPP) platoon formation control problem of unmanned surface vehicles (USVs) with connectivity preservation and collision avoidance. Each vehicle is subject to unmeasured velocities, model uncertainties, external disturbances and actuator input delay. By introducing a finite-time performance function (FTPF), the desired transient and steady-state performances can be guaranteed in finite time, which makes the line-of-sight (LOS) error and angle error be limited within the desired constraints to achieve collision avoidance and connectivity maintenance. Furthermore, a relevant variable containing constrained upper and lower bounds is designed to further realize the FTPP with asymmetric properties. In order to recover unmeasured velocity information, estimate uncertain dynamics of the vehicle and compensate for external disturbances, an extended state observer (ESO) based on position-heading information is proposed. Thereinto, the event-triggered mechanism is introduced to reduce the communication burden from the sensor to the observer channel. The effects of actuator input delay are eliminated by using the Pade approximation transform. A second-order linear tracking differentiator (TD) is introduced into the kinematic design to avoid the measurement of acceleration in the dynamics control design. The stability analysis shows that the proposed control scheme ensures that all signals of the USVs are bounded, and the Zeno behavior will not occur. Moreover, the distance between the two neighboring USVs converges to the prescribed range, meanwhile, the tracking angle error limits to a desired arbitrarily small region within finite time. Finally, the simulation results further confirm the effectiveness of the proposed control scheme.