Control of Reusable Hypersonic Launch Vehicles
Funded by AFRL/ AFOSR within the Collaborative Center of Control Science, and by the DAGSI Fellowship Program.
Collaborators: Prof. Steve Yurkovich, ECE, Dr. David Doman, AFRL/VA.
Graduate students supported:
Jason Parker (PhD Candidate, supported by a NSF Fellowship)
David Orn Sightorsson (PhD Candidate)
Kevin Groves (Master Candidate, supported by DAGSI).
Expected completion of the project: September 2007.
The first topic within the project regards the design of robust, fault-tolerant control allocation algorithms for RLVs. The purpose of the control allocation portion of a guidance and control architecture for reentry vehicles is to distribute control power among redundant control effectors to meet the desired control objectives under a set of constraints. We propose the use of model-based predictive control techniques to deal at the same time with nonnegligible actuator dynamics, the presence of hard constraints on the magnitude and rate of the control signals, and the possible occurrence of faults. Results based on an accurate model of an experimental reusable launch vehicle are reported in [1], [2], and [3], while a journal paper is in preparation. The second topic, which is expected to take a prominent role as the project evolves, regards the control of airbreathing hypersonic vehicles with integrated airframe-propulsion systems. The particular shape of vehicles of this sort, required by the unique characteristics of the propulsion system, poses severe challenge in the design of guidance and control systems, due to structural flexibility and strong couplings between the airframe and the propulsion dynamics. The applicability of design techniques based on robust control theory which avoid the use of dynamic inversion is currently under investigation. Preliminary results on control design for a linearized model are reported in [4].

Relevant publications:
  1. Y. Luo, A. Serrani, S. Yurkovich, D.B. Doman, and M.W. Oppenheimer. Dynamic control allocation with asymptotic tracking of time-varying control trajectories. In Proceedings of the 2005 American Control Conference, Portland, OR, 2005.
  2. Y. Luo, A. Serrani, S. Yurkovich, D.B. Doman, and M.W. Oppenheimer. Model predictive dynamic control allocation with actuator dynamics. In Proceedings of the American Control Conference, Boston, MA, 2004.
  3. V. Poonamallee, S. Yurkovich, A. Serrani, D.B. Doman, and M.W. Oppenheimer. A nonlinear programming approach for control allocation. In Proceedings of the American Control Conference, Boston, MA, 2004.
  4. K. P. Groves, D. O. Sightorsson, A. Serrani, S. Yurkovich, M. A. Bolender, and D. B. Doman. Reference command tracking for a linearized model of an air-breathing hypersonic vehicle. Submitted to the AIAA Guidance Navigation and Control Conference, San Francisco, CA, 2005.