Robust control design for electrically driven high-pressure pumps using H∞ approach with joint shaping functions

Various applications use high-pressure pumps for waterjet machining. A cutting head generates the waterjet, which is capable to cut hard and brittle materials. These cutting heads induce pressure fluctuations that originate from enabling and disabling the waterjet with respect to an a priori unknown switching law. Any pressure fluctuation will degrade the cutting quality. Thus, the primary control objective is to reject these disturbances by means of the high-pressure pump. Furthermore, waterjet applications show significant uncertainties that necessitate a robust control design. This paper presents the robust control design for a specific electrically driven high-pressure pump. Consequently, H
_∞
controller synthesis is employed, taking into account expected parameter variations, exogenous disturbance and control requirements. This work introduces joint shaping functions, resulting in a reduced H
_∞
optimization problem. Subsequently, the obtained controller is verified on a validated simulation model.