Adaptive limit detection and avoidance for carefree maneuvering

This paper describes a novel technique for predicting limit parameter values and calculating the corresponding control margins of an aircraft. This new approach utilizes an observer type adaptive neural network loop for the estimation of the correct aircraft model. The constructed aircraft model is then used to predict the quasi-steady response behavior of the limit parameters and the corresponding control margins using a second adaptive neural network loop. Though the approach does not require any off-line training of the neural networks, existing off-line trained neural network data maps can be accommodated in the procedure. Only standard sensor measurements are used for adaptation. A detailed development of the method along with simulation evaluation of the method using a linear helicopter model and a nonlinear tiltrotor model are included.