Comprehensive Processing And Performance Evaluation Of Airliner Navigation Information Based On RNP Requirement

Required navigation performance is a new technology by using the aircraft's own airborne navigation equipment and global positioning system to guide the aircraft take-off and landing,which is the future development trend of navigation recognized by International Civil Aviation Organization.and it is also a operation mode promoted by the Civil Aviation Administration of China.RNP technology relieves aircraft dependence on land-based navigation equipment,facilitates the application of new navigation technologies and methods,and makes the use of airspace more flexible.The essence of RNP is the integrated management of onboard navigation information,evaluation of navigation system performance and requirements of timely alarm capability.High precision is the primary requirement of the positioning performance for onboard navigation systems during RNP operation.However,under the perturbation environment,the traditional fusion method of the navigation system has insufficient anti-interference ability.Integrity is another important performance index for the navigation system during RNP operation.Satellite navigation system is the main navigation device during RNP operation in the future,enhancement of its integrity performance is of great significance.But the autonomous integrity monitoring performance of the stand-alone satellite navigation system is not enough.Actual Navigation Performance(ANP)is a very important criterion for the crew to decide whether the requirement is meet during RNP operation.But the current assessment of ANP is still a lack of systematic research.Therefore,in view of the above problems,based on the comprehensive analysis of the function and performance requirements of navigation system during RNP operation,the paper mainly studies the multi-source information fusion method,the integrity monitoring method and the actual navigation performance evaluation method of the airborne navigation system.The main purpose of our work is to improve the accuracy and integrity,meanwhile to realize the evaluation of the actual navigation performance in RNP operation.So that onboard performance monitoring and alarm can be achieved.The composition and function of the avionics system and flight management system has been analyzed in this paper.Then,the different navigation performance indexes that need to be satisfied during RNP operation are described.According to the current RNP operation and implementation specification,the composition and classification of the total system error in RNP operation is introduced in this paper,and the allocation method of RNP performance index is studied.Based on the requirement of onboard navigation system during RNP operation,the configuration and function planning of multi-source heterogeneous navigation system in civil airliner are studied.Then,the different navigation performance indexes that need to be satisfied during RNP operation are described,which can provide support for the key technology research of navigation system information processing in RNP operation.In order to enhance and guarantee the accuracy of the navigation system performance,an adaptive multi-model filtering algorithm based on self-regression modeling of colored noise is proposed to effectively improve the accuracy of the inertial / satellite integrated navigation system under the color noise.Then,aiming at the nonlinearity and time-varying noise characteristic of the inertial/land-based integrated navigation system,an adaptive cubature kalman filter method based on maximal a posteriori estimation and fading factor is proposed.The method solves the problem of large positioning error and divergence caused by the high-order truncation of the linear filtering method,and effectively improves the accuracy of the filter estimation when the noise statistic characteristic changes.So the accuracy of inertial/land-based integrated navigation system performance is enhanced.In order to ensure the monitoring performance of satellite navigation system integrity,this paper presents an integrity monitoring method based on support vector regression.The fault subsystem can be accurately identified to ensure the integrity of the navigation system.Meanwhile,the paper studies the satellite integrity monitoring method aided by other navigation equipment.An aircraft autonomous integrity monitoring method based on weighted parity vector is proposed in this paper.The proposed method can provide more redundant observation information,and can effectively detect and identify faulty satellites in real time when the number of satellites is low or when multiple faults occur simultaneously.So the integrity of the satellite system can be ensured.To achieve real-time navigation performance evaluation and monitoring,Considering the difference of ANP evaluation method under different navigation modes,a set of corresponding actual navigation system evaluation methods is proposed for single navigation mode and integrated navigation mode.At the same time,this paper studies and puts forward a performance evaluation method based on numerical integration and binary iteration.The method can realize the accurate evaluation of ANP under the position bias,and provide monitoring of the navigation system performance status and change tendency for flight crew.Thus onboard alarm can be achieved in real time,which can ensure the flight safety and reliability.Finally,This paper designs and realizes a set of ground simulation verification platform of airborne navigation system based on RNP operation,which can effectively validate the integrated processing and evaluation method of navigation information,and assess the applicability of different navigation modes in RNP operation.The platform has been applied in the ground integrated simulation verification system of C919,which can provide a good simulation and verification method for testing information integrated management and performance assessment of airborne navigation system.