Application of Zakian´s majorants to robust controller design for hydraulic force control systems

The paper presents the design of a robust controller for a hydraulic force control system using Zakian´s majorants, in which a two-degree-of-freedom configuration is used. The design objective is to ensure that the error and the control signals always stays within prescribed bounds in the presence of all inputs having bounded magnitude and bounded slope. The design problem is formulated so that all possible inputs are explicitly taken into account. Accordingly, the design objective is expressed as a set of inequalities that can be solved in practice. A numerical example with two parameter uncertainties is carried out.