Multilevel Modeling of an Unmanned Rotorcraft and Robust Controller Design for Trajectory Tracking

According to numerous capabilities and increasingly military and commercial applications of radio controlled helicopters, many investigations are being performed on these unmanned aircraft vehicles. Due to nonlinear, complex, unstable and coupled dynamic system and also existing limitations on manual control, the ability of automatic control of these vehicles has gained great importance. In this paper, in addition to investigating different methods of unmanned helicopters dynamic modeling, a multi-level simulator environment has been designed and implemented for flight performance analysis and effects of different parameters have been investigated. The main importance and innovation of present simulator is in possibility of dynamic flight simulation of helicopter using different theories for applications like control system design, performance analysis and real flight simulation. The main difference of the utilized methods is in theories and assumptions applied in main rotor and its flapping dynamics modeling. For each level, Kalman filter and control system design have been performed and preliminary results show the acceptable performance of estimator and controller systems. Considering the complexity of real unmanned helicopter behavior compared to previously performed models, the proposed multi-level simulator can be used as an appropriate tool for the first step before real flight tests.