ESTERA project objective was to develop and deliver prototype of Closed-Loop Control System optimized for Active Flow Control actuation applied at the wing’s trailing edge or wing’s body and used for drag reduction / buffeting control in high-lift and high-speed aircraft operations. The project objective was achieved by:

• acquiring requirements imposed on CLC-System (particularly in terms of working conditions, wing geometry and sensors / actuators location);
• numerical simulations of air flow speed and pressure at wing surface (without and with working actuators) to define regulation goals (pressure values that shall be achieved) and to select the best control strategy;
• building system-under-control mathematical model;
• selection of control techniques to be tested (PID, LQR, adaptive, hybrid, others);
• definition of test cases and scope of tests;
• construction CLC-System Mock-up from already available parts;
• testing of selected control techniques on wing model in wind tunnel provided by Consortium and their iterative improvement / efficiency optimization due to test results with support of MATLAB tool (applying stochastic and evolutionary algorithms);
• finally production and delivery of CLC-System prototype to SFWA.

Multi–level distributed CLC-System was proposed, constructed of signal conditioning units embedded in sensors, sub-controllers embedded in actuators and main controller, connected in digital communication network (e.g. ARINC 429). This construction improved CLC-System efficiency by separation of tasks performed at high and low level as well as improve CLC-System reliability by independency of local sub-controllers. CLC-System Prototype was miniaturised using FPGA/CPLD technologies to be embedded in AFC actuators and sensors. CLC-System prototype was designed, developed, documented and tested (EMC & climatic tests) according to required standards (DO-160F, DO-178B, DO-254, EMC, etc.) to ensure possibility of obtainment of EASA certificate.