Research on Control Strategy of Electro-Hydraulic Loading Device of Ship Shafting
In order to simulate the load of the ship shafting in the laboratory environment,an electro-hydraulic loading device based on controllable varied volume of contained liquid was studied in this paper.The mathematic model of this device was deduced.Based on the analysis of the model,the key factor that affects the accuracy of loading force control was the axial movement of the rotatory shafting.A novel com-posite control strategy based on a modified disturbance observer and feedforward compensation was pro-posed.The loading device was composed of loading hydraulic cylinder,enclosed vessel and hydraulic valves.Firstly,a semi-closed-loop pressure control structure was constructed to improve the stability of the sys-tem.Then,to attenuate the load force fluctuation,a disturbance observer was used to estimate an equiva-lent disturbance from axial movement.The compensation was introduced at the control input by using the equivalent disturbance.Finally,the effectiveness of the proposed control strategy was verified by numerical simulations and field experiments.It is shown that the designed composite control strategy could attenuate the load force fluctuation effectively.
disturbance observerfeedforward compensationloading deviceelectro-hydraulic servo system
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维普
