Continuous Integral Robust Control of Electro-Hydraulic Systems With Modeling Uncertainties

This paper studies the high-performance tracking control of electro-hydraulic systems with consideration of both mismatched and matched modeling uncertainties. A continuous integral robust control strategy is proposed based on the backstepping design framework. By introducing a novel error transformation, the mismatched modeling uncertainty can be transmitted to the control input channel, and then, the constructed integral robust structure in the proposed controller can handle it together with the matched modeling uncertainty. The acceleration signal that usually suffers heavy noise contamination is not required in the controller, and the final control input is continuously differentiable, which is benefit for tracking performance improvement and practical controller implementation. The closed-loop system stability is analyzed via the Lyapunov theory, and it reveals that the proposed controller achieves an asymptotic tracking performance with zero steady-state error in the presence of various modeling uncertainties. Comparative experiments are performed to demonstrate the effectiveness of the proposed control strategy.