In this work, we propose a minimalistic swarm flocking approach for multirotor unmanned aerial vehicles (UAVs). Our approach allows the swarm to achieve cohesively and aligned flocking (collective motion), in a random direction, without externally provided directional information exchange (alignment control). The method relies on minimalistic sensory requirements as it uses only the relative range and bearing of swarm agents in local proximity obtained through onboard sensors on the UAV. Thus, our method is able to stabilize and control the flock of a general shape above a steep terrain without any explicit communication between swarm members. To implement proximal control in a three-dimensional manner, the Lennard-Jones potential function is used to maintain cohesiveness and avoid collisions between robots. The performance of the proposed approach was tested in real-world conditions by experiments with a team of nine UAVs. Experiments also present the usage of our approach on UAVs that are independent of external positioning systems such as the Global Navigation Satellite System (GNSS). Relying only on a relative visual localization through the ultraviolet direction and ranging (UVDAR) system, previously proposed by our group, the experiments verify that our system can be applied in GNSS-denied environments. The degree achieved of alignment and cohesiveness was evaluated using the metrics of order and steady-state value.

翻译：本文提出了一种用于多旋翼无人机的极简集群方法。该方法使集群能够在没有外部提供方向信息交换（对齐控制）的情况下，沿随机方向实现具有内聚性和对齐性的集群运动。该方法依赖极简的传感要求，仅使用无人机机载传感器获取的邻近集群智能体的相对距离和方位。因此，我们的方法能够在陡峭地形上空稳定和控制任意形状的集群，而无需集群成员之间进行任何显式通信。为实现三维近端控制，采用Lennard-Jones势函数来维持内聚性并避免机器人之间的碰撞。所提方法的性能通过一个由九架无人机组成的团队在真实环境下的实验进行了验证。实验还展示了该方法在独立于全球导航卫星系统等外部定位系统的无人机上的应用。仅依靠我们团队先前提出的紫外线定向与测距系统进行相对视觉定位，实验验证了我们的系统可在GNSS拒止环境中应用。使用有序度和稳态值指标评估了所实现的对齐性和内聚性程度。