Distributed Predefined-Time Leader–Follower Formation Control for Heterogeneous Wheeled Mobile Robots

This paper investigates the predefined-time (PdT) formation control problem for heterogeneous wheeled mobile robots (WMRs) with complex nonlinear terms. To address the challenges arising from system heterogeneity and distributed coordination, a reference-tracking control framework is proposed. The first layer is a reference signal generation layer, where PdT formation trajectories are generated by signal generators, with local observers embedded in each agent to estimate the leader’s state when direct access is unavailable. The second layer is an agents tracking layer, where each WMR follows its assigned reference trajectories. By coordinating these two layers, the proposed framework enables distributed formation control within a predefined time. To achieve PdT tracking, a sliding mode control strategy enhanced with fuzzy logic control is developed in the tracking layer. Lyapunov-based analysis is conducted for both layers to ensure PdT stability and provide explicit convergence-time guarantees. Simulation results are presented to validate the theoretical analysis and demonstrate the effectiveness of the proposed method.