Integrated Flight/Propulsion Control

Objective

The integrated approach developed at NASA Glenn is a systematic top-down method to design control laws for systems that consist of multiple interacting subsystems. In the classical approach to integrated control, separate (decentralized) control laws are designed for each subsystem and then integrated in an ad hoc manner to account for the interactions between the subsystems. This decentralized approach results in sub-optimal system performance, which may lead to extensive redesign of system control laws if the overall system performance is unacceptable. In the NASA-developed approach, a centralized control law that considers all the subsystem interactions is designed first; then these control laws are partitioned for decentralized implementation. The centralized design provides a baseline for optimal achievable system performance, and controller partitioning yields implementable decentralized controllers that best match the optimal system performance for a given decentralized control architecture.

The integrated control design approach has been successfully demonstrated for an Integrated Flight and Propulsion Control (IFPC) design for a conceptual Short Take Off Vertical Landing (STOVL) aircraft.

Pilots successfully completed critical transition phase tasks in grc simulation facility. Good tracking of velocity and flight path commands with little pitch disturbance.

Technologies Developed

• H-infinity based control synthesis formulation for robust control law design.
  • Generic structure for command tracking
  • Rules of thumb for weight selections
• Parameter optimization based scheme for synthesis of Integrator Wind-up Protection gains
  • Guarantees controller and closed-loop stability for single actuator saturation.
• Simplified controller scheduling scheme
  • Exploits robustness of nominal design to schedule only controller output matrix.
• Systematic procedure for partitioning centralized controller into subsystem controllers.
  • Matches centralized system performance and robustness

Accomplishments

• Developed IMPAC (Integrated Methodology for Propulsion and Airframe Control), a systematic procedure addressing future high performance aircraft needs.
• Demonstrated IMPAC through IFPC (Integrated Flight/Propulsion Control) design for conceptual STOVL (Short Take-Off Vertical Landing) aircraft.
• Developed multivariable control techniques applicable to a wide variety of problems and transferred technology to industry through various programs.

Project Contact

Sanjay Garg
NASA Glenn Research Center
21000 Brookpark Road, M.S. 77-1
Cleveland, Ohio 44135
Phone: (216) 433-2685
email: sanjay.garg@grc.nasa.gov

responsible official: sanjay garg
site maintenance: edmond wong
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last updated: 2.29.08