Motion control design for an electro-hydraulic actuator under ensured performance

Unknown time-variant parameters and disturbances, obstructing the improvement of motion control performance, ubiquitously exist in Electro-Hydraulic Actuator Systems (EHASs). To surmount this issue, by integrating the dynamic surface control, the adaptive technique and a preset-time performance function, an adaptive preset-time performance controller is exploited for EHASs, in which unknown time-variant parameters and disturbances are disposed of simultaneously, and the complexity explosion problem is avoided. Moreover, an introduced preset-time performance function can guarantee that all the control errors are restricted into a preset region in a specified time. Theoretical analysis reveals that both the boundedness of all the system signals and the zero-error steady performance can be ensured with this presented method while the preset-time transient performance of all the control errors is ensured as well. Comparative experiment results also reveal the merits of this method.