Broadcast event-triggered control scheme for multi-agent rendezvous problem in a mixed communication environment

• Main Authors: Sariff, N., Ismail, Z. H.
• Format: Article
• Language: English
• Published: MDPI AG 2021
• Subjects: T58.5-58.64 Information technology
• Online Access: http://eprints.utm.my/id/eprint/94046/1/ZoolHilmiIsmail2021_BroadcastEventTriggeredControlScheme.pdf; http://eprints.utm.my/id/eprint/94046/; http://dx.doi.org/10.3390/app11093785
• Institution: Universiti Teknologi Malaysia

This paper addresses the communication issue encountered by a hybrid controller when finding consensus in terms of the rendezvous target point in a broadcast and communication environment. This issue may result in a high level of computation and the utilization of agent resources when a continuous communication is required by agents to meet convergence requirements. Thus, an event-triggered system was integrated into the design of a broadcast and distributed consensus linear controller using the simultaneous perturbation stochastic algorithm (SPSA). The agent’s movement towards the rendezvous point is based on the broadcast value, whereas the next agent’s state position depends on the distributed local controller output. The communication error obtained during communication between the agent and neighbors is only added to the gradient approximation error of the SPSA if the event-triggered function is violated. As a result, in our model, the number of channel utilizations was lower and the agents’ performances were preserved. The efficiencies and effectiveness of the proposed controller have been compared with the traditional sampling broadcast time-triggered (BTT) approach. The time and iterations required by the broadcast event-triggered (BET) system were less than 40.42% and 21% on average as compared to BTT. The trajectory was not the same—the BET showed scattered movements at the initial stage, whereas BTT showed a linear movement. In terms of the number of channels, 28.91% of channels were preserved during the few hundred iterations. Consequently, a variety of hybrid controllers with event-triggered mechanisms can be proposed for other multi-agent motion coordination tasks.