TRAJECTORY TRACKING H2 CONTROLLER FOR AUTONOMOUS HELICOPTERS: AN APPLICATION TO INDUSTRIAL CHIMNEY INSPECTION

This paper addresses the problem of industrial chimney inspection using autonomous helicopters. The importance of using these platforms is evidenced by the maintenance cost and risk reduction stemming from the replacement of the standard procedures and the improved detection of structural defects. The approach presented relies on the definition of a trajectory-dependent error space to express the dynamic model of the vehicle, and adopts a Linear Parameter Varying (LPV) representation with piecewise affine dependence on the parameters to model the error dynamics over a set of predefined operating regions. The synthesis problem is stated as a continuous-time H2 control problem, solved using Linear Matrix Inequalities (LMIs) and implemented within the scope of gain-scheduling control theory. The effectiveness of the proposed controller is assessed in simulation using the full nonlinear model of a small-scale helicopter.