Research On Modeling And Control Methods For Unmanned Helicopter

Unmmanned helicopter is widely used in the military and the civil areas due to its unique advantages. Control system design, as a key technology in the helicopter autonomous flight, is becoming a hot research topic. In this paper, unmanned helicopter is taken as controlled object and a mechanism model is given based on analysis of helicopter's flight dynamics. Then a cascaded multi-loop PID controller are designed and fight tests in different flight models are performed, the initial PID control parameters adjustment was completed basically. A large amount of flight data were obtained by multiple flight test in hovering, The model parameters identification was performed based on this data and the accuracy of flight dynamics model is improved. Finally, some advanced control algorithms are performed on this model and their effectiveness are validated through simulation.Firstly, a six-degrees dynamic model is built based on aerodynamic analysis of the helicopter. Then, linearization is performed using small perturbation theory and a state-space equation of the system is obtained. The open-loop characteristics of this model are analyzed and linear and nonlinear models, as well as a three-dimensional simulation interface are constructed in MATLAB.Then, a flight control system which use the cascaded multi-loop PID control as its core control algorithm in hovering is introduced based on the existing hardware platform of flight control system. The reliability of this system is verified through autonomous hovering flight tests. The flight data obtained from the above tests, together with the mechanism structure model, are used to indentify the model parameters and the results are validated. The identification method used in this paper integrates the advantages of mechanism modeling and system identification modeling and thus leads to the improvement of model accuracy.Finally, some advanced control algorithms are acted on this helicopter model in MATLAB. The strengths and weaknesses of the algorithms are discussed and it is helpful for the improvement of core control algorithm in the helicopter control system.