Finite-Time Adaptive Dynamic Surface Control for Energy Recovery Loading Systems Based on Command Filter

We develop an energy-recovery loading system capable of imposing configurable hydraulic loads for comprehensive pump performance evaluation. This system recuperates hydraulic energy through a pump–motor–generator cascade that transforms fluid power into grid-compatible electrical energy, thereby minimizing energy loss and thermal dissipation. However, achieving precise pressure tracking within such an architecture poses significant control challenges due to inherent hydraulic nonlinearities, mechanical transmission losses, and parametric uncertainties. To overcome these challenges, we propose a novel hybrid control strategy that integrates Command-Filtered Adaptive Dynamic Surface Control (CF-ADSC) with Fractional-Order Sliding Mode Control (FOSMC). The CF-ADSC framework decomposes complex system dynamics into tractable subsystems with real-time parameter adaptation, while FOSMC enhances robustness against disturbances through the use of fractional calculus operators. A rigorous Lyapunov-based stability analysis confirms the finite-time convergence of tracking errors. Comparative simulations and experimental validations demonstrate that the proposed controller maintains pressure tracking errors within 2% under dynamic loading conditions, offering a robust and energy-efficient solution for advanced hydraulic performance testing.