Drive flexibility and friction in control of hydraulic actuators: a robust adaptive nonlinear control design

In this paper, a robust adaptive nonlinear controller is presented for hydraulic actuators. The model utilized for the hydraulic actuators includes nonlinear relations between the flow velocity and the pressure, parametric uncertainties due to environmental changes, bulk modulus, inertia mass, oil temperature and valve dynamics. Moreover, transmission flexibility and friction in the drive are considered in the control synthesis. Utilizing our earlier results in robust adaptive nonlinear control and friction compensation, we present a control design methodology for dealing with the aforementioned parametric and dynamic uncertainties in hydraulic actuators. The efficacy of the advocated control design methodology is shown through simulation studies