Robust Control of Aerospace Systems
The focus of this research is on the development of robust
control system design methodologies for
aerospace systems.
Application Areas
Relevant application areas include:
- Aero-thermo-elastic-propulsion effects for air-breathing hypersonic aircraft e.g. X-43A, SOAREX, X-51A
- Powered and unpowered hypersonic gliders/waveriders
- Fixed-wing aircraft
- Rotary-aircraft
- Tilt-wing rotorcraft (TWRC)
- Multi-Lift helicopter applications; e.g. twin-lift helicopter system (TLHS)
- Missile Guidance, Navigation, and Control (GNC) Systems
- Satellite systems
- GNC for unpiloted air vehicles (UAVs)
- Autonomous and semi-autonomous vehicles
- Coordination of multiple cooperating vehicles
Special focus has been placed on hypersonic application for which aero-thermo-elastic-propulsion interactions are particularly significant.
Relevant Control Challenges
Relevant control challenges include:
- uncertain nonlinearities (e.g. aero-thermo-elastic-propulsion),
- hard nonlinearities (e.g. control position and rate saturation nonlinearities),
- uncertain (typically high-frequency) dynamics; i.e. unmodeled differential equations,
- parametric uncertainty,
- uncertain actuator and sensor dynamics,
- MIMO dynamical coupling/interactions (e.g. aero-thermo-elastic-propulsion),
- satisfying multivariable decoupling specifications,
- satisfying channel-specific bandwidth specifications,
- satisfying MIMO directionality specifications,
- controller complexity and implementation issues,
- digital, sample-data, and multi-rate embedded system implementation issues,
- uncertain actuator and sensor dynamics,
- aero-servo-elastic issues, aero-servo control reversal, aero-servo control flutter,
- selection of weighting function parameters for dynamical optimization,
- assessment of fundamental performance limitations and tradeoffs,
- stabilization,
- following of varying (typically low frequency) reference commands,
- attenuation of (stochastic, typically low frequency) disturbances,
- attenuation of (stochastic, typically high frequency) measurement noise,
- control law adaptation and scheduling; e.g. on angle-of-attack (AOA), side-slip-angle (SSA), Mach number, control surface deflection, propulsion setting,
- aero data reduction, interpolation, extrapolation,
- constraint enforcement e.g. AOA, SSA, Mach number, acceleration, aeroservo control deflection,
- state estimation,
- model validation via wind tunnel and flight test data,
- control law tuning from wind tunnel testing and flight test,
- parameter and uncertainty estimation (system identification),
- actuator and sensor degradation,
- structural degradation,
- fault tolerance.
Objectives and Goals
The main objective of this research is to develop a systematic design methodology which addresses each of the above control system design challenges. A major goal here is the development of tools that can be used by practicing engineers to design "full envelop" MIMO control systems.
Collaborators and Sponsors
Collaborators include:
- Professor Petros Voulgaris (University of Illinois, Urbana-Champaign; Aerospace Engineering)
- Dr. Brett Ridgely (Raytheon Missile Systems, Sr Department Manager, Autopilot Design Department, GNC Technology Director, Tucson, AZ)
- Professor Jeff Shamma (UCLA; Mechanical Engineering)
- Valana Wells (ASU, Mechanical and Aerospace Engineering)
This work has been sponsored by the following organizations:
- National Science Foundation (NSF), the Consortium for Embedded and Inter-Networking Technologies (CEINT), AFOSR, Eglin AFB, Honeywell, Boeing, NASA.
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