Adaptive Nonlinear Model Inversion Control of a Twin Rotor System Using Artificial Intelligence

The paper investigates the development of an adaptive dynamic nonlinear model inversion control law for a twin rotor MIMO system (TRMS) utilizing artificial neural networks and genetic algorithms. The TRMS is an aerodynamic test rig representing the control challenges of modern air vehicles. A highly nonlinear 1DOF mathematical model of the TRMS is considered in this study and a nonlinear inverse model is developed for the pitch channel. In the absence of model inversion errors, a genetic algorithm-tuned PD controller is used to enhance the tracking characteristics of the system. An adaptive neural network element is integrated thereafter with the feedback control system to compensate for model inversion errors. In order to show the effectiveness of the proposed method in the simulation environment an inversion error has deliberately been provided as an uncertainty in the real situation. Square and sinusoidal reference command signals are used to test the control system performance, and it is noted that an excellent tracking response is exhibited in the presence of inversion errors caused by model uncertainty.