Model Predictive Controller Used in Guidance with Obstacle Avoidance of Multirotor Aerial Vehicles

José Agnelo Bezerra Guilherme Silva¹; Davi Antônio dos Santos¹

¹ Instituto Tecnológico de Aeronáutica

doi:10.20906/CPS/CON-2016-1018

Resumo

This article deals with the problem of waypoint-based guidance of multirotor aerial vehicles with avoidance of multiple polytopic obstacles. In order to solve the problem, a formulation of a robust model predictive controller (RMPC) is proposed. The command inputs to the controller consist of a sequence of tridimensional waypoints as well as a reference speed. In the case with no obstacles close to the multirotor, the future reference trajectory embedded in the MPC is chosen as a straight line, traveled with the reference speed, towards the next waypoint of the sequence. A waypoint is detected as soon as the vehicle enters inside a specified Euclidean ball centered at it. At the same moment, the next waypoint of the sequence is switched on. This rule is repeated until reaching the final waypoint, at which the vehicle is commanded to hover. When a polytopic obstacle is close to the vehicle, the avoidance method is activated with two independent actions: a constant deceleration is introduced in the reference trajectory and the convex optimization space to MPC is reduced based on a simple method that considers both the previous and next waypoints. The proposed method is evaluated by computational simulations, showing that its effectiveness in guiding a multirotor vehicle throughout the waypoints, with approximately the reference speed, even in the presence of multiple obstacles and under disturbance forces.

Palavras-chave: Model Predictive Control; Multirotor Aerial Vehicles; Waypoint Navigation; Obstacle Avoidance