Design Of Semi-Physical Simulation System For ILS Space Signal Of An Airport

This paper has completed the design of semi-physical simulation system based on NM7000 system platform.Through the industrial computer,extracted the signal data generated by the NM7000 device,and transmitted the extracted signal data to the computer via the serial cable.According to the composition of the system(gliding system and localizer system),a mathematical model is established for the relationship between gliding width,gliding angle,localizer width and localizer angle.Based on the mathematical relationship model,the computer performs and completes the signal simulation.The mathematical modeling steps are as follows: Firstly,based on the sufficient analysis of the working principle of the ILS system,the modulation depth difference(DDM)between the localizer system and the gliding system is theoretically studied.Then,according to the principle of NM7000 equipment adjustment,the control variable method and the least squares principle are used to establish the relationship between the amplitude of SBO signal and the glide width and localizer width in the linear variation range of DDM.According to the principle of spatial signal synthesis,a mathematical model of DDM about the amplitude changes of 90 HZ and 150 HZ signals is established.Based on the model,DDM,90 HZ signal amplitude,150 HZ signal amplitude and glide angle and localizer angle are established by using control variable method and least square method.Finally,the above mathematical model is calibrated based on actual school-based data and empirical data.This article has completed the simulation software development based on Labview and MATLAB.Simulation software can not only display the glide width,glide angle,localizer width,localizer angle of the simulation adjustment process,but also on the check flight process simulation.In order to increase maneuverability and comprehensibility,the software visualizes and simulates the process of adjusting and adjusting the signals of different perspectives(such as pilot perspective,top viewing angle,left viewing angle,etc.)as needed.By establishing a simulation platform,the process of adjusting the gliding signal and the localizer signal of the ILS system is verified.The verification results show that the designed semi-physical simulation platform of ILS system has high accuracy,reliability and stability,and the simulation software interface is friendly and easy to operate.The system can realize a number of functions of the ILS system adjustment,can guide the adjustment process of the ILS system,and can be used as a teaching software to train the ATC staff for technical training.