Fail-safe encircling of multiple unmanned aerial vehicles with bearing only measurements

Abstract

This paper presents a cooperative strategy to achieve evenly spaced circular formation of a group of unmanned aerial vehicles. The strategy is claimed to be fail-safe because the circular formation remains unaltered even if one or more unmanned aerial vehicles fail. We can also add more unmanned aerial vehicles without altering the formation. The control law uses only bearing angle information. We can pre-specify the centre of the circular formation of the unmanned aerial vehicles. The unmanned aerial vehicles will maintain the desired distance from the centre with bearing angle measurement only. We assume that the unmanned aerial vehicles are identical and can measure the bearing angle of all the other unmanned aerial vehicles. The strategy is analysed using unicycle kinematic and verified using sixdegree-of-freedom model of the unmanned aerial vehicles. Extensive simulations are carried out for noisy measurement, presence of wind and moving target.

A Survey on Techniques in the Circular Formation of Multi-Agent Systems

“…In some scenarios such as tracking, the application of the bearing measurements necessitate some observability conditions [103]. CFP by using bearing-only measurements is studied in [45,47,104]. Different from the bearing measurements, the bearing-only measurements require the agents to calculate only the bearing angle without any relative position measurements [101].…”

“…The results have been extended to CCM stabilization with phase arrangements using second-order rotational dynamics in [42]. A fail-safe strategy based only on the bearing measurements is proposed using unicycle kinematics to achieve the balanced circular formation where the center may or may not be pre-specified [47].…”