Thispaperinvestigatesthedesignofamodelreferenceadaptivesliding mode state feedback control for MEMS gyroscopes. It isassumed that all states of the system are known. In a separatework we show how this restrictive assumption can be avoided byuse of a sliding mode observer [17]. The controller proposed hereuses a novel sliding mode algorithm consisting of a proportionalFig. 6. Smooth sliding mode control force of the adaptive sliding mode controller.Fig. 7. Nonsmooth sliding mode control force of the adaptive sliding modecontroller.and integral sliding surface. An adaptive sliding mode controlleris derived to control the axes of the gyroscope and to estimatethe unknown angular velocity. Furthermore a smooth version ofthe adaptive sliding mode controller is used to reduce the controlchattering. The proposed adaptive sliding mode control structurewith proportional and integral sliding action can handle withboth matched and unmatched uncertainties and disturbances,provided that upper bounds for these uncertainties are available.Simulation results demonstrate that the use of the proposedproportional–integral sliding mode adaptive control techniqueis effective in estimating the gyroscope parameters and angularvelocity in the presence of matched and unmatched disturbances.