Cooperative Control Strategy for Multiple Electro-Hydraulic Manipulators in Rail Grinding Trains

To address the synchronization challenges in high-precision position cooperative control of multiple electro-hydraulic manipulators during rail grinding train operations, we propose a distributed sliding mode cooperative control algorithm based on a virtual leader. First, to mitigate the strong nonlinearity of the electro-hydraulic drive system and the inherent chattering problem of sliding mode control, a linear sliding mode controller with a novel reaching law incorporating an exponential decay term is designed. This approach ensures rapid convergence of system states while effectively smoothing the control gain transition and reducing actuator chattering. Second, a multi-agent cooperative framework based on a virtual leader is established, and a distributed cooperative control strategy requiring only neighbor node information is developed. Compared with traditional deviation-coupled control, this method significantly reduces the system communication burden, achieves high-precision tracking of the grinding displacement command and operational synchronization among follower manipulators, and provides a rigorous stability proof based on Lyapunov theory. Finally, comparative simulations with several typical control schemes on the Matlab platform demonstrate that the proposed method exhibits stronger robustness against nonlinear disturbances in the electro-hydraulic system, with significantly reduced synchronization errors among manipulators. Hardware-in-the-loop validation results based on RT-LAB confirm that the proposed distributed architecture ensures high-precision cooperation of multiple grinding heads under complex working conditions.