This article presents the design and implementation of an event-triggered control approach, applied to the leader-following consensus and formation of a group of autonomous micro-aircraft with capabilities of vertical take-off and landing (VTOL-UAVs). The control strategy is based on an inner–outer loop control approach. The inner control law stabilizes the attitude and position of one agent, whereas the outer control follows a virtual leader to achieve position consensus cooperatively through an event-triggered policy. The communication topology uses undirected and connected graphs. With such an event-triggered control, the closed-loop trajectories converge to a compact sphere, centered in the origin of the error space. Furthermore, the minimal inter-sampling time is proven to be below bounded avoiding the Zeno behavior. The formation problem addresses the group of agents to fly in a given shape configuration. The simulation and experimental results highlight the performance of the proposed control strategy.

This paper presents the development of a collaborative event-based control applied to the problem of formation of a group of VTOL-UAVs (Vertical Takeoff and Landing, Unmanned Aerial Vehicles). Each VTOL-UAV decides, based on the difference of its current state (linear position and velocity) and its latest broadcast state, when it has to send a new value to its neighbors. The asymptotic convergence to average consensus or desired formation is depicted via a real-time implementation.

No abstract

This paper presents the development of a quaternion-based nonlinear event-triggered control for the attitude stabilization of Flying robots. Firstly, it is proved the existence of a Control Lyapunov Function. Unlike some previously proposed schemes, the aim of this paper is to propose a new and simpler event function. The control law ensures the asymptotic stability of the closed-loop system to the desired attitude. The approach is validated in real-time using a quadrotor mini-helicopter. The experiments show that the event driven controller reduces the control update without deteriorating the closed-loop system performance. I. INTRODUCTION Flying robots and Unmanned Aerial Vehicles (UAVs) have received growing interest in industrial and academic research. They may prove useful for many civilian missions. Furthermore, among miniature rotorcraft-based UAVs, the mini quadrotor helicopter gives rise to great interest because of its high manoeuvrability, its payload capacity and its ability to hover, as explained in [1]. Such a Vertical TakeOff and Landing (VTOL) vehicle has some advantages over conventional helicopters: owing to symmetry, it is relatively simple to design and construct. In fact, the quadrotor is an under-actuated dynamic system with four input forces and six output coordinates (attitude and position). However, this system can be broken down into two subsystems, one defining the translation movement and the other one the rotation movement. These subsystems are coupled in cascade since the translational subsystem depends on the rotational one, but the rotational subsystem is independent of the translational one. Self-governing flights require the generation of low-level control signals sent to actuators as well as decision-making related to guidance, navigation. Low-level flight control is known as attitude control and it is responsible for maintaining the desired vehicle orientation. Consequently, the attitude controller design is, in itself, a challenge. Some linear and nonlinear control techniques have been applied for the attitude stabilization of the quadrotor, like for example in [2], [3], [4], [5], [6], [7], [8].

This article presents the design and development of an event-triggered control strategy to solve the problem of leader-following consensus and formation problem for a group of UAVs carrying a suspended load individually. In this work, the vehicles exchange information through a network, which is represented by a directed and strongly connected graph. Then, employing a decentralized control law, each UAV decides when it has to send a new value to its neighbors. The stability of the complete system is carried out, and numerical results show the advantages wrt information exchange between UAVs, as well as excellent performance in the angular stabilization and the minimum swing for the suspended load.