Dynamic impact of hydraulic systems using pressure feedback for active damping

摘要

Pressure feedback has been an effective method for active damping and oscillation reduction in hydraulic systems. However, this study reveals a dynamic impact problem of a larger velocity overshoot and slower convergence excited by an external force/torque disturbance once pressure feedback is introduced for active damping. This problem is introduced through a theoretical analysis, and then illustrated by a numerical simulation. The solutions to this problem are analysed for a hydraulic system with a symmetric cylinder. For a trade-off between the active damping effect and reduction in dynamic impact, a multi-objective optimization method is proposed to determine the control parameters (gain and time constant) of the high-pass pressure filter. The multi-objective optimization method is validated by a simulation model with the symmetric cylinder under different disturbances. Moreover, an analysis is carried out for the system with an asymmetric cylinder or hydraulic motor. The theoretical analysis shows that the mathematical forms of the two systems are similar to that of the symmetric cylinder system. Therefore, the dynamic impact problem also exists in the two systems. The proposed method is also effective for the damping improvement and mitigation of the dynamic impact.