Finite-Time Sliding Mode Coordinated Control for Multi-Robot Arms with Hydraulic Proportional Actuation

This paper presents a finite-time sliding mode consensus control strategy for multi-hydraulic-arm systems operating in confined environments. A distributed master-slave framework is proposed to realize coordinated motion. To improve convergence and suppress chattering, a smooth hyperbolic tangent sliding surface is incorporated. A nonlinear proportional valve model is introduced to represent hydraulic dynamics. Theoretical stability is established via Lyapunov analysis. Simulation results under a sinusoidal reference trajectory-selected for its ability to reflect synchronization performance-demonstrate accurate tracking, rapid convergence, and robustness to initial condition variations, confirming the effectiveness of the proposed control scheme for nonlinear hydraulic coordination tasks. The control framework is particularly tailored for coal bunker cleaning tasks, where hydraulic robots operate under spatial and environmental constraints.