Three Degree Of Freedom Helicopter Trajectory Optimization Spectrum Method Based On Gauss Collocation Reconstructiom

As a typical representative of the helicopter family,the three-degree-of-freedom helicopter has the characteristics of high order,strong coupling and non-linearity,which has become the focus of research at home and abroad.Trajectory planning is one of the key technologies of helicopter,which is very important to the intelligent control and mission implementation of helicopter.During the flight of the helicopter,the interference from the external environment will make the flight control more difficult;At the same time,the model characteristics of the helicopter system are changed by the influence of flight action.In the design of helicopter flight controller,if these influencing factors are not considered,the model mismatch will be caused and the performance of flight trajectory tracking will be reduced.It has become the mainstream of current research to analyze the above problems by using efficient optimal control theory combined with tracking control algorithm.Therefore,this thesis takes the three-degree-of-freedom model helicopter as the research platform,researches on its dynamic trajectory optimization modeling,solution and tracking control algorithm,and obtains trajectory optimization and LQR tracking control theory of three-degree-of-freedom helicopter based on Gauss collocation reconstruction.The main research contents of this thesis are as follows:(1)According to the characteristics and characteristics of the 3-DOF helicopter simulation platform,the dynamics of pitching axis,rolling axis and rotation axis are analyzed respectively,and the dynamics model is established.Then,the time scale transformation of the established three degree of freedom helicopter dynamics model is carried out,and the model is transformed into a standard problem suitable for the trajectory planning algorithm,which lays a solid foundation for the trajectory planning method research of three-degree-of-freedom helicopter simulation platform.(2)Aiming at the deficiency of orthogonal configuration method in solving complex optimization problems,an orthogonal configuration method based on two-stage adaptive mesh reconstruction was proposed.Firstly,the orthogonal configuration method was used to solve the optimal solution of the control variables and state variables.Then,sensitivity variation rules were designed to refine and merge the discrete time grid to form a two-stage adaptive grid.Finally,the original problem was solved again.The simulation results show that the efficiency of the proposed method is significantly improved in solving the trajectory planning problem of 3-DOF helicopter.(3)Aiming at the problems of model mismatch and external environment interference in the actual working conditions of helicopters,a tracking control method based on orthogonal configuration method combined with LQR was proposed.The optimal state variables were obtained by using the reconstructed orthogonal configuration method,then the optimal state variables were taken as the ideal input,the appropriate weight matrix was selected,and the optimal control rate based on state programming was calculated by combining with LQR.Finally,the optimal control rate was input into the dynamic model and the output was monitored.The simulation results show that the proposed method has a significant suppressing effect on the problems such as model mismatch and external environment interference existing in the actual working conditions of the 3-DOF helicopter simulation platform.