Practical Fixed‐Time Formation Control for Wheeled Robots: An Approach Based on Time‐Base Generators

ABSTRACT Under the dual constraints of preset time limits and coupled nonlinear dynamics, it is extremely challenging to achieve cooperative control and strong robustness guarantees for multi‐agent systems. This paper focuses on the fixed‐time formation control for nonholonomic wheeled mobile robots (NWMRs) via time‐base generator (TBG). To begin with, distributed fixed‐time formation controllers are developed to eliminate the dependence of traditional controllers on initial values. Subsequently, TBG incorporates time‐dependent functions to design control strategies with either asymptotic or non‐asymptotic characteristics, ensuring system convergence within a fixed time. Limiting the magnitude of control inputs not only safeguards actuators but also improves the system's robustness to external disturbances and model uncertainties. Additionally, a distributed observer based on a TBG is designed to enable each follower to estimate the state of the virtual leader within a fixed time. The observers of the followers can operate independently, eliminating the need for a global clock or precise synchronization, thereby simplifying the system design. Eventually, the effectiveness and superiority of the controller are verified by simulation. Compared with the traditional fixed‐time consensus protocol, the proposed protocol reduces the amplitude of the initial linear velocity by 32.1% and the angular velocity by 32.2%. The settlement time can be preset offline, and the estimation of the settlement time is significantly more accurate.