基于非线性块反步控制的无人直升机 航迹跟踪算法研究.

In view of the characteristics of the small-scale unmanned helicopter system which is highly nonlinear, strongly coupled and susceptible to internal and external disturbance, this paper proposed a control strategy combining nonlinear block back-stepping control with generalized proportional integral observer. In this method, at first, it used a generalized proportional integral observer to construct a multi-order observation loop and to estimate the system state variables, disturbances and the multi-order derivatives of disturbances, and then it added the estimated value of disturbance into the helicopter system model and adapted back-steeping method to obtain the tracking flight controller of the helicopter. Numerical simulation results of step signal and complex trajectory tracking show that, the designed controller has an ideal dynamic response performance, tracking capability and disturbance attenuation ability under the influence of various internal and external disturbances. Compared with the nonlinear disturbance observer, the generalized proportional integral observer has a higher estimation accuracy for high order and fast time-varying disturbances and achieves better disturbance suppression effects. [ABSTRACT FROM AUTHOR]