Distributed Observer for Rigid Spacecraft Systems over Jointly Connected Switching Networks and Its Applications

Abstract

The distributed observer, which is a distributed dynamic compensator that provides an estimation of the leader system's information with the communication constraints satisfied, is a powerful tool for solving various cooperative control problems of multi-agent systems with leader-follower structures. The distributed observer approach has two advantages over other approaches. First, it can handle jointly connected communication networks that can be disconnected at every time. Second, the design of the distributed observer and the design of the control law are decoupled due to the triangular structure of the whole system. This talk consists of two parts. In each part, we will introduce a type of distributed observer for a 6-DOF rigid spacecraft system. In the first part, we present a distributed observer that estimates the leader system’s position over jointly connected switching networks. Then we apply this observer to solve the global time-varying formation problem. In the second part, we propose an event-triggered distributed observer for the leader’s attitude over jointly connected (acyclic) switching networks. This observer updates the inter-agent information only when some triggering conditions are satisfied, thus reducing energy consumption. We will show that, under some standard assumptions, the state of the event-triggered distributed observer will exponentially converge to the leader's state and the inter-event time admits a positive lower bound, which prevents the Zeno phenomenon from happening. Then, we apply the event-triggered distributed observer to solve the leader-following consensus problem.

 

Speaker

Dr Tianqi WANG is a Postdoctoral Fellow in the Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong. He received his BEng degree in Flight Vehicle Design and Engineering from Harbin Institute of Technology in 2017 and Ph.D. degree in Mechanical and Automation Engineering from The Chinese University of Hong Kong in 2021. His research interests include cooperative control of multiple rigid spacecraft systems, model predictive control, event-triggered control, and cyber-physical systems. His research on rigid spacecraft systems has been published in various top peer-reviewed journals including IEEE Transactions on Aerospace and Electronic Systems, IEEE Transactions on Neural Networks and Learning Systems, and International Journal of Robust and Nonlinear Control. He has also been invited twice to contribute papers to the invited session “Event-triggered and self-triggered control” at IEEE Conference on Decision and Control.