A Virtual Linkage-Based Dual Event-Triggered Formation Control Strategy for Multiple Amphibious Spherical Robots in Constrained Space With Limited Communication

Aiming to deal with the formation maintaining in constrained space for a group of robots, this paper proposed a virtual linkage-based dual event-triggered formation control strategy. Based on the idea of virtual linkage and event-trigger, a dual event trigger is proposed to guarantees robot formation keeping and collision avoidance. Unlike classical event-triggered control, the control strategy triggered by the detection of the state of virtual linkage determine the motion mode of the robot, which can reduce the control updating and eliminate continuous communication between robots. Moreover, an adaptive control law inspired by the motion of a simple pendulum was developed to adjust the given angle of the virtual linkage in the case that the multi-robot system pass the restricted region. Finally, to validate the performance of the formation control strategy, simulations and a series of experiments in an indoor swimming pool are presented. The results demonstrate the robustness and feasibility of the proposed formation control strategy.