Path planning techniques are of major importance for the motion of autonomous systems. In addition, the chosen path, safety, and computational burden are essential for ensuring the successful application of such strategies in the presence of obstacles. In this context, this work introduces a modified potential field method that is capable of providing obstacle avoidance, as well as eliminating local minima problems and oscillations in the influence threshold of repulsive fields. A three-dimensional (3D) vortex field is introduced for this purpose so that each robot can choose the best direction of the vortex field rotation automatically and independently according to its position with respect to each object in the workspace. A scenario that addresses swarm flight with sequential cooperation and the pursuit of moving targets in dynamic environments is proposed. Experimental results are presented and thoroughly discussed using a Crazyflie 2.0 aircraft associated with the loco positioning system for state estimation. It is effectively demonstrated that the proposed algorithm can generate feasible paths while taking into account the aforementioned problems in real-time applications.

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Ahstract-This paper presents a robust control strategy for regulating dc-link voltage of shunt active power filters without load current measurements. The dc-link of these schemes suffers when a load variation occurs. To compensate these effects a robust control strategy based on an adaptive pole placement control strategy integrated to a variable structure control scheme V S -AP PC is proposed. In this control strategy the dc-link voltage regulator generates the filter reference currents based on the system active power balance. With this control scheme, rises or drops on the dc-link voltage due to the load variation are significantly reduced. The effectiveness of the proposed control strategy is demonstrated by comparisons with standard control schemes implemented with proportional-integral PI or PI controller associated with feed forward scheme. Experimental results are also carried out to demonstrate the advantages of the proposed method.

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