Research On Flight Control Of An Unmanned Tandem Rotor Helicopter

Unmanned tandem rotor helicopters are widely used in the military and civilian sectors for their excellent transportability.However,Unmanned tandem rotor helicopters are strong coupling,high nonlinearity and complex systems,which exacerbates the problem of a high performance flight control system design.This paper presents a new adaptive attitude control method combining the reference model and the track model,and make flight comparison experiment based on self-designed dual-core controller.The results show the superiority of the new adaptive control method.First of all,a full-scale nonlinear model of unmanned tandem rotor helicopter is developed by using the method of independent-component modeling,and the change of attitude angle and steering trimmed amount under different forward flight speeds are studied.The linearized mathematical model is obtained based on the small perturbation linearization method,and the unmanned helicopter performance is analyzed through stability and coupling.Secondly,a dynamic decoupling controller is designed for the longitudinal-lateral coupling of the unmanned tandem rotor helicopter.Based on this decoupling system,the conventional attitude controller and the position controller are designed.Simulation results show that the controller can effectively control the unmanned tandem rotor helicopter.Thirdly,aiming at the influence of measurement noise,trim error and uncertainty of aerodynamic parameters on attitude control of unmanned tandem rotor helicopter,this paper presents a new adaptive control method combining reference model and track model,make convergence analysis of adaptive parameters.According to the simulation results,the adaptive control structure is improved to solve the adverse effect of measurement noise on the convergence of adaptive parameters.Simulation results show that the improved adaptive controller has a good attitude tracking effect.Finally,based on the characteristics of DSP and ARM controller,a dual-core controller with wide applicability and rich functions is designed to realize the independent operation of data acquisition and flight control.The unmanned tandem rotor helicopter flight control software and ground software are designed and make flight experiments.The results show that the new adaptive control method has better control quality than the conventional control method.