Ainikkal, Shaiju JohnyPetersen, Ian Richard2026-07-032026-07-0397839026610051474-6670ORCID:/0000-0003-4856-9450/work/219177628https://hdl.handle.net/1885/733812359This paper presents an approach to discrete time robust $H^infty$ control for a class of nonlinear uncertain systems based on the use of Sum Quadratic Constraints. The approach involves controllers which include copies of the system nonlinearities in the controller. The nonlinearities being considered are those which satisfy a certain global Lipschitz condition. The linear part of the controller is synthesized using linear robust $H^infty$ control theory and this leads to a nonlinear controller which gives an upper bound on the attainable disturbance attenuation level.enControl problems under conflict and/or uncertaintiesRobust control of nonlinear systemsRobust controller synthesis200810.3182/20080706-5-KR-1001.209479961018263