Designing a hierarchical model-predictive controller for tracking an unknown ground moving target using a 6-DOF quad-rotor

Abstract

In this paper, a hierarchical predictive controller is designed in order to solve the tracking problem of a moving ground target by a quad-rotor in an unknown and uneven environment. This controller has internal and external predictive controller levels. In the lower layer of the controller, a constrained predictive controller is designed that is capable of rejecting perturbations and quickly tracking the reference path, and in the outer loop, a model predictive controller is designed to optimally detect the moving ground target where, the sub-cost functions were defined so that the quad-rotor would be able to track the moving ground target even if it was temporarily out of sight of the flying robot, as well as in the event of sudden direction changes and uneven path. In this method, since there is no need to switch between different controllers and not having to engage in delusional maneuvers of the target, the total control effort is reduced, which was shown in the simulations by the indifference reactions and shortening of the path of the quad-rotor. Finally, the tracking problem is simulated in the MATLAB to show the effectiveness of the proposed controllers, and the results are compared with that of a benchmark controller.