Leader–follower formation control of two quadrotor UAVs

Abstract

This paper reports the design and implementation of a leader-follower (L-F) formation control of two Parrot AR Drone 2.0 quadrotor UAVs (drones). In order to implement such control, three control elements were developed. These were the flight-dynamic characteristics, the position tracking and L-F formation control, and the data communication system between drones and ground-control station. The dynamic characteristics were identified as the first-order process with time delay models, which were asymmetrical to x − , x + , x − and x + directions. Accordingly, dedicated Proportional-Derivative (PD) controllers were designed for the respective models. A Pole-Placement strategy was applied to design the PD controllers in order to achieve a non-oscillatory position tracking. These controllers were combined with five operating modes to form an F-L formation control. The controls were implemented on two-drones and one-ground-control station. The ground-control station dictated a prescribed path for the leader drone. Subsequently, the leader position became follower set-point. During the implementation test, these drones completed their L-F formation. The follower drone tracked the y-axis coordinate of the leader's drone and maintained a safe distance to the respective x-axis coordinate. The accuracy of the controls was measured in terms of the root mean squares errors, and these were within 50-115 cm.

A review on drones controlled in real-time

“…A set of sensors, such as TV cameras, infrared cameras, thermal sensors, chemical, biological sensors, meteorological sensors etc., used to gather information during drone applications need to be lightweight to reduce UAV payload [ 41 – 44 ]. The information gathered from the sensors can be partially processed on-board or transmitted to the ground station for further processing [ 45 – 47 ]. An on-board controller, separate from the flight controller, can be used to operate the payload sensors [ 48 – 50 ].…”

UAVs-UGV Leader Follower Formation Using Adaptive Non-Singular Terminal Super Twisting Sliding Mode Control

“…For the formation control of quad-rotors with attached slung load, a Lyapunov function based guidance algorithm is used, with a linear quadratic tracking controller [27]. Rifqi et al implement a Leader-follower formation controller for two parrot AR drones, where a dedicated PD controller is designed for the respective models [28]. A distance based formation controller is designed for the formation and tracking control of quad-rotors in leader-follower formation which has the capabilities of collision avoidance via Lyapunov barrier functions [29].…”

Adaptive Robust Trajectory Tracking Control of Multiple Quad-Rotor UAVs with Parametric Uncertainties and Disturbances

“…A guidance algorithm based on Lyapunov function is used for the formation control of quad-rotors with attached slung load, where the quad-rotors are controlled using linear quadratic tracking controller [ 27 ]. Leader follower formation controller is designed for two parrot drones in [ 28 ], where a proportional derivative controller is implemented in the respective models. The problems related to formation and tracking control of quad-rotors in leader follower formation are addressed and a formation controller is designed to avoid collision in swarm [ 29 ].…”