Distributed extended state observer based formation tracking control of under-actuated unmanned surface vehicles with input and state quantization.

This paper delves into the distributed formation control of unmanned surface vehicles (USVs) under conditions of simultaneous input and state quantization. The primary objective is to ensure that USVs in the formation can effectively follow the specified trajectory in a bandwidth-limited communication environment. A distributed extended state observer (ESO) is proposed to observe the state information of the virtual leader in the USV formation. Furthermore, another ESO is introduced to address the impact of uncertainty terms in the ship model and quantized state variables during communication on the formation control system. Subsequently, the USVs formation guidance laws are formulated in the kinematics subsystem. In addition, the quantized control laws are described linearly in the kinetics subsystem so that the USVs distributed formation controller does not need to anticipate specific information about the quantization parameters. Meanwhile, the USVs formation tracking underlying control laws are designed in the quantized environment to achieve the tracking of the desired kinematic guidance signal. Then, the stability of the designed distributed formation tracking control system for USVs is proved using Lyapunov stability theory. Finally, the effectiveness of the proposed strategy is validated through two sets of simulation experiments, providing empirical evidence of its practical applicability. • Compared to the existing formation tracking control methods for USVs, this paper investigates distributed formation tracking control of USVs with input and state quantization in complex marine communication environments, which reduces the actuator execution frequency without significantly sacrificing the control quality. • Compared with the prior research addressing state quantization in control systems, this paper introduces a distributed ESO to indirectly address the effect of quantized state variables on the designed control system during the transmission of communication signals between USVs. • Unlike current quantized control methods, which setting parameters in quantizers as constant or adjustable within specific constraints, this paper utilizes a linear model to describe the input quantization process, eliminating the need for a priori parameter information of the quantizer. [ABSTRACT FROM AUTHOR]