Study on Dual-loop Controller of Helicopter Based on the Robust H-infinite Loop Shaping Method

Helicopter is a typical MIMO system including the properties of non-stability, strong coupling, uncertainty. Firstly, a robust internal loop ACAH controller is designed and analyzed to ensure decoupling and robustness on each channel by the robust H-infinite loop shaping. Secondly, the external loop is designed using the classical PID method on the base of decoupling internal loop. Both loops contain the part of anti-windup. The simulation results of the prototype model demonstrate that in both time and frequency domain, the performance of the controller meets the design requirement with a comparative simple structure. The results can also prove that it has some effect against to the model perturbation and achieve LEVEL1 of ADS-33E-PRF.