Triangular formation control with mixed distance and bearing measurements under limited field of view constraints

This article addresses the problem of triangular formation control for a three-agent group with different measuring capabilities: agent 1 can measure local bearings but with limited field of view (FOV), and agents 2 and 3 can only obtain distance measurements. For agent 1, an orientation controller is first designed to steer its heading to the expected direction. Furthermore, a type of switching control law utilizing pure bearing measurements is proposed to reach the desired angle with respect to the other two agents. Concurrently, it is guaranteed that the flip ambiguity of the formation can be excluded. For agents 2 and 3, the extended distance-based control algorithm is proposed by invoking the so-called signed area strategy to determine their actuation. With this control scheme, it is proven that the triangular formation is stabilized globally even in the presence of FOV constraints. The effectiveness is validated through numerical simulations and physical experiments on three nano quadrotors.