Force control of a hydraulic servo system

Abstract

The objective of this thesis is to model a hydraulic servo system using force control and then improve upon the performance of the model/system through feedback control design. The hydraulic system is first constructed and tested. Experimental data based linear models of the system are found through input-output measurements. The models contain a right-half-plane zero; therefore, a bandwidth limitation is placed on the control design (i.e. the bandwidth frequency of the control system is limited). Three types of controllers (P, PID, and H[infinity]) are designed specifically for the linear models. The closed-loop time domain and frequency domain performance of each control system is found and compared for the models and system. Uncertainties and performance weights are finally used in finding the nominal/robust stability and performance.