Rapid Integration, Development and Flight Test of Helicopter Flight Control Laws

In 2009, Bell Helicopter developed and flight test advanced optimal/robust control laws. An innovative rapid prototyping process was employed utilizing real-time Matlab/Simulink® executing on a rugged laptop to develop and flight test the control laws on a fly-by-wire test bed aircraft. Control law gain margin, phase margin, bandwidth calculation and compensator selection were designed using Bell's three loop optimization technology Matlab/Simulink® M-file algorithm. A desktop simulator was used to merge the control laws with a non-linear COPTER math model S-function for simulation testing. A COPTER math model running in Bell's Simulation Lab assisted in real-time Simulink® integration, logic testing and pilot's flight control force feel system tuning. Both full and partial authority advanced control laws were evaluated in the National Research Council of Canada (NRC) Bell Model 412 Advanced Systems Research Aircraft. Technology demonstrations were conducted and selected handling qualities maneuvers were performed to evaluate the capabilities of the new control laws.