Receding horizon control of a 6-DOF model of the raptor 50 helicopter: robustness to changing flight conditions

This paper presents the results of a feasibility study that examined the use of the receding horizon control technique in stabilizing a 6 degree-of-freedom simulation of the Thunder Tiger Raptor 50 V2 remote controlled helicopter. The longitudinal and lateral-directional dynamics of the Raptor 50 helicopter are simulated using a linear parameter varying force model that has been verified against actual flight test data. Due to the changing dynamics of the helicopter, the problem of developing a controller that was robust to model uncertainty needed to be addressed. The receding horizon control technique was chosen due to its ability to change the control law gain which ameliorates the handling qualities of the helicopter in simulations. Assuming an infinite time horizon, the receding horizon control technique can be formulated as a linear matrix inequality optimization problem. This LMI formulation allowed for a tractable solution in computer time. While the goal of stabilizing the helicopter was met in various flight conditions, the issue of real-time implementation needs to be further addressed