Robust gain-scheduled linear parameter-varying control algorithm for a lab helicopter: A linear matrix inequality–based approach

The control performance of aerial vehicles can be easily affected by measurement error in sensor output, dynamic model error, model parameter variation, parametric uncertainty, external disturbance, and dynamic coupling. This article presents a design of robust linear parameter-varying control technique with induced L₂-norm performance combined with linear matrix inequality pole region constraints for a lab-scale helicopter. A linear parameter-varying disturbance rejection observer is constructed that characterizes the L₂-norm performance of the linear parameter-varying system, which enables to estimate state information not only in the presence of external disturbance but also in case of fault occurrence or unavailability of some sensor output. Therefore, the proposed robust linear parameter-varying control scheme has the tendency to provide an adaptive control solution for stability proof and robust tracking performance. The performance of the proposed technique is confirmed both in simulation and in real time. Compared to conventional output feedback H_∞ control technique, the proposed control technique yields a good tracking performance in the presence of disturbance, parameter variation, and dynamic coupling.