Coordinated multi-robot trajectory tracking control over sampled communication. (May 2023)

• Record Type: Journal Article
• Authors: Rossi, Enrica; Tognon, Marco; Ballotta, Luca; Carli, Ruggero; Cortés, Juan; Franchi, Antonio; Schenato, Luca
• Is Part Of: Automatica. Volume 151(2023)
• Publication Date: 2023-05
• Subjects: Control over sampled communications -- Distributed control -- Multi-robot systems -- Trajectory tracking -- UAVs; Automatic control -- Periodicals; Automation -- Periodicals; 629.805
• DOI: 10.1016/j.automatica.2023.110941
• Languages: English
• ISSNs: 0005-1098

Abstract

Abstract: In this paper, we propose an inverse-kinematics controller for a class of multi-robot systems in the scenario of sampled communication. The goal is to make a group of robots perform trajectory tracking in a coordinated way when the sampling time of communications is much larger than the sampling time of low-level controllers, disrupting theoretical convergence guarantees of standard control design in continuous time. Given a desired trajectory in configuration space which is pre-computed offline, the proposed controller receives configuration measurements, possibly via wireless, to re-compute velocity references for the robots, which are tracked by a low-level controller. We propose joint design of a sampled proportional feedback plus a novel continuous-time feedforward that linearizes the dynamics around the reference trajectory: this method is amenable to distributed communication implementation where only one broadcast transmission is needed per sample. Also, we provide closed-form expressions for instability and stability regions and convergence rate in terms of proportional gain k and sampling period T . We test the proposed control strategy via numerical simulations in the scenario of cooperative aerial manipulation of a cable-suspended load using a realistic simulator ( Fly-Crane ). Finally, we compare our proposed controller with centralized approaches that adapt the feedback gain online through smart heuristics, and show that it achieves comparable performance.