Abstract
The model-based flight control system design for a highly flexible flutter demonstrator, developed in the European FLEXOP project, is presented. The flight control system includes a baseline controller to operate the aircraft fully autonomously and a flutter suppression controller to stabilize the unstable aeroelastic modes and extend the aircraft’s operational range. The baseline control system features a classical cascade flight control structure with scheduled control loops to augment the lateral and longitudinal axis of the aircraft. The flutter suppression controller uses an advanced blending technique to blend the flutter relevant sensor and actuator signals. These blends decouple the unstable modes and individually control them by scheduled single loop controllers. For the tuning of the free parameters in the defined controller structures, a model-based approach solving multi-objective, non-linear optimization problems is used. The developed control system, including baseline and flutter control algorithms, is verified in an extensive simulation campaign using a high fidelity simulator. The simulator is embedded in MATLAB and a features non-linear model of the aircraft dynamics itself and detailed sensor and actuator descriptions.
Highlights
Today’s aircraft manufacturers are eager to fulfill the greener imperative demanded by society and allow for a more economic operation of aircraft
A reduction of aircraft weight is achieved by using new materials like carbon composites, as it has been successfully achieved for example with the Airbus A350 or the Boeing 787, where higher aspect ratios yield reduced aerodynamic drags
The soft and hard design constraints f and g in Equations (14) and (15), respectively, are defined using classical control objectives in the frequency and time domain. This includes desired bandwidth, robustness margins, overshoot, tracking error, rise time, maximum loop gains, and desired loop shapes. Another possibility used in this article is to provide a reference model and use the error between this reference model and the resulting dynamics as criteria to be minimized in either Equation (14) or (15)
Summary
Today’s aircraft manufacturers are eager to fulfill the greener imperative demanded by society and allow for a more economic operation of aircraft. Possible countermeasures are active control techniques which allow for stabilizing these unstable dynamics and extending the operational region of the aircraft Such advanced control algorithms require model-based design methods which call for adequate models of the aeroservoelastic effects. A major task during the design of active flutter suppression algorithms is the adequate fusion of the numerous available measurements on the wings and the different control inputs. By defining the structure of the controllers in advance, the design of the flutter suppression controller as well as the baseline controller reduces the selection of adequate control gains The verification includes wind scenarios to test the disturbance attenuation, acceleration scenarios to verify the stabilization capabilities of the active flutter control algorithm, and flights along the predefined flight test pattern on which the real flight tests will be performed
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
