Robust Formation Control
Funded by AFRL/ AFOSR within the Collaborative Center of Control Science.
Graduate students supported:
Xingping Chen (Ph.D Candidate), Zhen Zhang (Ph.D Candidate).
Expected completion of the project: June 2006.
The main topic within this project addresses the use of internal-model based techniques and nonlinear input-output stabilization methods in the design of robust, decentralized control architectures for formation control of autonomous vehicles. In this approach, advances tool for stability analysis play a crucial role in assessing the influence of disturbance and uncertainties in the overall behavior of the formation. A key issue in maintaining stability of a formation of autonomous vehicles is the design of robust controllers that provide insensitivity to possibly large uncertainties regarding the motion of nearby agents, to the presence of transmission delays in the feedback path, and the effect of quantized information. Results concerning the robust control of formations of nonholonomic vehicles are reported in [1], while issues related to the analysis of formation stability are discussed in [2]. A related topic concerns the use of methodologies from nonlinear regulation theory for control of satellite formations on highly elliptical orbits. The challenge is to develop a theory of output regulation for general classes of periodic signals with infinite Fourier series [3], that will enable the design of robust control strategies for the synchronization of the orbital and attitude dynamics of satellites in formation flight, extending the results in [4].
Unmanned Aerial Vehicle  

Relevant publications:
  1. X. Chen and A. Serrani. Remarks on ISS and formation control. In Proceedings of the 2004 IEEE Conference on Decision and Control, Paradise Island, Bahamas, 2004.
  2. X. Chen, A. Serrani, and H. Özbay. Control of leader/follower formations of terrestrial UAVs. In Proceedings of the IEEE Conference on Decision and Control, Maui, HI, 2003.
  3. Z. Zhang and A. Serrani. The linear periodic output regulation problem. Submitted to the 2005 joint IEEE Conference on Decision and Control and European Control Conference, Seville, Spain, 2005.
  4. A. Serrani. Robust coordinated control of satellite formations subject to gravity perturbations. In Proceedings of the American Control Conference, volume 1, pages 302-307, Denver, CO, 2003.