Design Of Landing System Combining Satellite And Land Based Positioning Techniques With Kalman Filter

With the rapid development of the civil aviation industry,airports are in great need of improving daily throughput capacity.However,with the limit of airspace resources and airport resources,and the influence of objective factors such as weather,flight frequently delays at the airport,which is an issue that must be resolved.Landing is one of the most difficult and complex operations in the flight of an aircraft.The current aircraft landing mechanism adopts a single land-based instrument landing system.It is limited by the simplex glide path and low accuracy,often affects the aircraft landing process,which directly or indirectly caused delays in the flight.The purpose of this research is to design a more complete aircraft landing system,which integrates GPS and other satellite-based navigation system data with existing instrument landing systems,to increase the safety and reliability of aircraft landing system at lower economic costs and the level of blind landing system.This research first discussed the feasibility of the combination of the GPS system and the instrument landing system theoretically by analyzing the characteristics and the source of the error of the two systems.On this basis,the overall structure of the combined system is designed.Next,based on the analysis of the positioning principle of the instrument landing system,the mathematical relationship between the modulation degree difference and the angle and the transformation of the coordinate system are established,and the relative position information of the land-based navigation system is converted into the geocentric solid coordinate.Finally,a filtering algorithm is designed to integrate the navigation information of the global satellite navigation system with the signal of the instrument landing system and the navigation information of the rangefinder.This research adopted the group sensor method of kalman algorithm for data fusion designing,which allows different sources of navigation parameters to correct each other.The navigation parameters provided by the global satellite navigation system are used as the estimation process in the kalman filter,and the navigation parameters provided by the instrument landing system and DME are used as the observation process.Thus,the navigation information of the global satellite navigation system is integrated with the instrument landing system signal and the rangefinder navigation information to provide a calibrated coordinate of airplane.This research made both corresponding error analysis and feasibility analysis for the algorithm and scheme,using real data of Dalian Zhoushuizi International Airport as signal sources,using Matlab programming tools to verify the fusion results.The simulation results of the algorithm show that the combined system designed in this research can effectively reduce the distance error of the airplane from the slide line during the landing process.This research provides part of the solutions of the combined system in the actual construction,which provides ideas and references for the follow-up study and actual conversion test.