Nonlinear model following control with parameter identification for a 3 DOF model helicopter
This paper deals with two-input, two-output nonlinear model following control of a 3 DOF model helicopter. Since the decoupling matrix is singular, the nonlinear structure algorithm is applied for designing the controller. Moreover, a parameter identification scheme is introduced in the closed-loop system because the model dynamics are described linearly by unknown system parameters. Two parameter identification methods are discussed. The first one is based on the differential equation model. In experiment, it is hard to obtain good tracking control performance because of the inaccuracy of the estimated velocity and acceleration signals. The second one is designed for the dynamics model derived by integral operation of the differential equations. Hence, the identification algorithm does not require either
the velocity or acceleration signals. The experimental results show that the second method achieves better tracking objectives.
model helicopters, nonlinear control, model following control, parameter identification