On The Impact And Compensation Of Array Pointing Accuracy Introduced By Track Error Of Parallel Pedestal

Aiming the track error of the 2-DOF parallel antenna mount,this thesis analyzes the track errors introduced by manufacturing and daily wear.The mathematical model of the relationship between the orbit roundness error and track irregularitities of the track and the driving position of the antenna mount was established.Through a series of simulations,the influence of the orbit error on the pointing accuracy of the antenna array was analyzed.In addition,on the basis of the constructed error model,the track error of the two-degree-offreedom parallel antenna mount was compensated,and the feasibility and effectiveness of the method were verified.The main work of this thesis is as follows:First,the structure composition and movement principle of the 2-DOF parallel antenna mount were introduced,the selection method of the main structural parameters was proposed,and the degree of freedom of the mechanism was verified.According to the geometric relationship of the 2-DOF parallel antenna mount,the forward and inverse solution expressions were deduced.The correctness of the forward and inverse solution expressions was verified by numerical analysis of the simulation results.Finally,the singularity of the antenna mount was analyzed to verify the effectiveness of the model provides a theoretical basis for subsequent error analysis.Secondly,based on the circular orbit of the 2-DOF parallel antenna mount,the orbit roundness error of the orbit was studied,and the influence of orbit roundness error of the orbit on the driving position of the antenna mount was analyzed,and the least square ellipse was used for a set of circularity.The error data was fitted,the parameter equation of the oblique ellipse sweep angle was deduced,and the mathematical model of the relationship between the roundness error and the driving position of the antenna mount was established.According to simulation analysis,the correctness of the mathematical model was verified.Finally,a simulation analysis of the drive position error caused by the orbit roundness error was carried out,and the influence of this type of error on the drive running position was described.Furthermore,based on the circular orbit of the 2-DOF parallel antenna mount,the track irregularity error was studied,and the influence of the track irregularity error on the driving position of the antenna mount was analyzed.Aiming at the complex characteristics of track unevenness error measurement data,the moving least squares method is used to fit the track irregularity error data,which reasonably demonstrates the microscopic appearance of the track irregularity error.Finally,through the multi-rigid body dynamics analysis software,the method of adding a motion pair perpendicular to the track at the antenna mount drive was used to simulate the track irregularity error,and the typical antenna trajectory was simulated.The method is straightforward and effective,and has the advantages of intuitive modeling and convenient computation.Finally,combined with the previous analysis results of the orbit error of the 2-DOF parallel antenna mount,a mathematical model of the antenna front pointing error introduced by the orbit error was established by the closed-loop vector method.Aiming at the typical antenna trajectory,the simulation analysis of orbit roundness error,orbit unevenness error,and orbit comprehensive error were respectively performed,and the influence mechanism of orbit error on the front pointing accuracy was concluded,and the orbit error derived in this thesis was combined with the front pointing error model.The compensation value of the driving element was calculated through the kinematics equation,so as to realize the compensation of the orbit error of the antenna mount.The result shows that the method is fast in computation and able to effectively compensate the influence of the orbit error on the pointing accuracy.