A novel type-3 fuzzy controller for path tracking and beyond critical states stabilization of initially curved...

This paper introduces an innovative type-3 fuzzy controller developed for precise position control and extending the travel range of a micro-positioner with an initially curved profile. The nonlinear damped model of the micro-positioner is formulated using non-classical continuum theory. By considering a single mode of vibration, the nonlinear governing partial differential equation (PDE) of the system is converted into a nonlinear state-space representation. The robust type-3 fuzzy controller is designed to address position control challenges in the presence of uncertainties that cannot be described by parameters and unknown input limitations caused by electrostatic actuation constraints. Simulation results, supported by comparisons with other control strategies, demonstrate that the proposed type-3 fuzzy controller effectively achieves accurate position tracking and extends the travel range of the originally bent micro-beam into unstable regions, ensuring consistent and smooth control performance.