CN-121999641-A - Low-altitude navigation position credible early warning method and system

CN121999641ACN 121999641 ACN121999641 ACN 121999641ACN-121999641-A

Abstract

The invention relates to the technical field of low-altitude navigation and flight safety, in particular to a low-altitude navigation position credible early warning method and system, comprising the steps of acquiring multi-source cooperative data; the method comprises the steps of calculating to obtain a space reference position and a credibility level of a corresponding position, acquiring external standard time by a comprehensive satellite clock and a time service center, modeling risks or anomalies in real time to generate a dynamic quality field, generating multi-dimensional credibility factors, inputting the multi-dimensional credibility factors to a fusion decision engine based on a weight or machine learning model, outputting comprehensive credibility scores, triggering classified early warning response according to the comprehensive credibility scores and the overrun condition of each independent credibility factor, and generating a structured early warning message according to the judged early warning response. And constructing a multidimensional cross-validation and flight environment situation awareness model, realizing comprehensive credibility evaluation and hierarchical early warning, and realizing the upgrade from 'passive receiving correction' to 'active validation credibility', thereby obviously improving the safety and the robustness of low-altitude flight.

Inventors

ZHANG JIAN
ZHANG ZHIHUA
DING PENGHUI
ZHANG JIUYAN
LIANG XIANHONG
ZHAN YUN
HU ZHENBIAO
WANG ZHI
DING XIAOLONG

Assignees

青岛市勘察测绘研究院

Dates

Publication Date: 20260508
Application Date: 20260209

Claims (7)

1. The low-altitude navigation position credible early warning method is characterized by comprising the following steps of: step 1, acquiring multi-source cooperative data comprising target aircraft data, foundation enhancement network data and environment perception data through an air-ground safety data chain; Step 2, based on the foundation enhancement network CORS data and the GNSS original observation value of the target aircraft, resolving to obtain a high-precision and high-credibility space reference position and a credible level of a corresponding position, and acquiring external standard time by a comprehensive satellite clock and a time service center; Step 3, collecting and analyzing crowd-sourced GNSS observation data, carrying out signal quality analysis, labeling risks or anomalies, modeling in real time to generate a dynamic quality field, and updating an interference source database; step 4, calculating a plurality of independent credibility factors through parallel channels, and generating multi-dimensional credibility factors by combining the independent credibility factors with the cross verification of the spatial reference position calculated in the step 2; Step 5, inputting the multidimensional credibility factors into a fusion decision engine based on a weight or machine learning model, outputting comprehensive credibility scores, and triggering hierarchical early warning responses according to the comprehensive credibility scores and overrun conditions of each independent credibility factor; and 6, generating a structured early warning message according to the determined early warning response, and distributing the structured early warning message to the target aircraft, the ground control station and the low-altitude traffic control center through a low-altitude communication network.
2. The low-altitude navigation position-credible pre-warning method according to claim 1, wherein in step 1, the target aircraft data comprise a GNSS original observed value, a real-time position Pu calculated by the aircraft itself, a speed Vu, a time Tu, a flight attitude and a state parameter, and an attitude angle, an air pressure altitude and an airspeed from a flight control system; The foundation enhancement network data comprises the reference station state, satellite health state, precise ephemeris, differential correction and integrity information provided by the foundation enhancement network are obtained in real time through a stable and reliable optical fiber private network communication link; the environment perception data comprises the acquisition of a preset flight mission plan, airspace structure information, a temporary no-fly zone, the integrity state of other collaborative aircrafts broadcast, and known interference source database information.
3. The low-altitude-navigation-position-confidence-warning method according to claim 1, wherein in step 4, the confidence factors include a position error factor α_p, a time-delay verification factor α_t, a dynamics consistency factor α_k, a signal quality and environment factor α_s, and a airspace and rule-compliance factor α_f.
4. A low-altitude navigation position trusted early warning method according to claim 3, characterized in that the position error factor α_p is obtained by calculating the self-reported position Pu of the aircraft and the highly trusted reference position Pref, the time delay verification factor α_t is obtained by calculating the self-reported time Tu of the aircraft and the standard time Tref, and the position error factor and the time delay factor respectively indicate abnormality when the deviation exceeds a dynamic threshold set based on the protection level; the dynamics consistency factor alpha_K performs dynamics consistency check on the motion state calculated by using a high-reliability reference position Pref sequence or inertial measurement unit IMU data and the self-reported speed Vu and attitude information of the aircraft, and calculates the vector difference between the position deduction acceleration and the IMU measurement acceleration; The signal quality and the environmental factor alpha_S are obtained by comprehensively evaluating the GNSS signal quality received by the aircraft and the coincidence degree of the GNSS signal quality and the dynamic signal quality field; And the airspace and rule compliance factor alpha_F judges whether the real-time position Pu or the high-reliability reference position Pref calculated by the aircraft deviates from a preset flight plan route, invades a limited airspace or collides with a peripheral traffic situation.
5. The low-altitude navigation position-credible alert method according to claim 1, wherein in step 5, the alert response includes: the first stage is in a normal or monitoring state, and the comprehensive reliability Score is higher than a safety threshold value, and no early warning and continuous monitoring are carried out; Second, in the prompt or degradation state, the comprehensive credibility Score is reduced or a single non-key factor is abnormal, an operation prompt is sent out, and the navigation performance is recommended to be concerned; Third, in warning or suspicion state, at this time, comprehensive credibility Score is obviously reduced, or error verification factor alpha_P is obviously out of limit but dynamics is not abnormal temporarily, and deception or serious disturbance warning is sent out to prompt switching of standby navigation sources; and four stages, namely, in an emergency or failure state, wherein the comprehensive reliability Score is extremely low, a plurality of key factors are failed simultaneously, the navigation system is confirmed to be failed, the flight control system is switched to a standby navigation mode, and an emergency risk avoidance program is triggered.
6. A low-altitude navigation position trusted early warning system, comprising: The airborne intelligent terminal module integrates a GNSS receiver, a state sensor and a data communication unit at an aircraft end, and is used for collecting, preprocessing and uploading GNSS original data and state data, and receiving and executing an early warning instruction at the same time; The foundation enhancement network module provides high-precision differential correction data RTCM data flow and integrity information such as satellite health state, geometric factors, signal quality, availability and the like through GNSS reference stations and monitoring stations which are uniformly distributed in a certain area range; The trusted situation awareness processing center module is used for executing the low-altitude navigation position trusted early warning method according to any one of claims 1-5 as a core computing unit; The safety data communication network module is used for taking charge of real-time and reliable data interaction among the modules; The user interaction terminal module comprises an aircraft cockpit display, an operator remote controller and a low-altitude traffic control platform and is used for visually displaying the position, the credibility state and the early warning information of the aircraft.
7. The low-altitude navigational location confidence warning system of claim 6, wherein said confidence situational awareness processing center module comprises: The data receiving and processing interface is used for receiving the data flow and the environment sensing data from the airborne terminal and the foundation enhancement network in the step 1; The space-time position resolving engine is used for executing the step 2 and resolving the high-credibility reference position Pref and the standard time Tref; The dynamic signal quality field modeling engine is used for executing the step 3, fusing the crowd source data, constructing and updating a dynamic signal environment simulation field map covering the service area in real time, and updating an interference source database; the multidimensional verification engine is used for executing the step 4 and parallelly calculating multidimensional credibility factors comprising a position error factor alpha_P, a time delay verification factor alpha_T, a dynamics consistency factor alpha_K, a signal quality and environment factor alpha_S and a airspace and rule consistency factor alpha_F; the intelligent fusion decision device is used for executing the step 5, integrating a fusion decision engine and realizing comprehensive evaluation and early warning grade judgment; and the early warning information interaction interface is used for executing the step 6 and providing standardized early warning information output for the aircraft, operators and the low-altitude traffic control center.

Description

Low-altitude navigation position credible early warning method and system Technical Field The invention relates to the technical field of low-altitude navigation and flight safety, in particular to a low-altitude navigation position credible early warning method and system. Background With the open and commercial utilization of low-altitude airspace, unmanned aerial vehicle logistics, manned eVTOL, aerial inspection and other application scenes are increasing. GNSS is used as a navigation and positioning core means of low-altitude aircrafts, and in low-altitude complex electromagnetic and geographic environments, signals are extremely vulnerable to electromagnetic interference, multipath effects and malicious spoofing attacks. These threats may cause the aircraft to acquire erroneous position, velocity, and time (PVT) information, causing serious accidents such as collisions, yaw, or crashes. The prior art mainly has the following limitations: 1. The protection means is passive, and most schemes such as autonomous integrity monitoring (RAIM) or signal quality monitoring of a receiver only carry out local alarm after abnormality occurs, and lack active verification capability based on external high-reliability position references. 2. The information dimension is single, the evaluation is mostly dependent on the GNSS observation value of the aircraft, the group perception information provided by the networking infrastructure (such as foundation enhancement network) and other aircrafts is not fully utilized, and the early detection capability of the environment risk is insufficient. 3. The pre-warning lacks predictability, that is, the traditional method is difficult to predict the signal environment risk of the forward route of the aircraft, and prospective route planning or risk avoidance cannot be supported. Therefore, there is an urgent need for a comprehensive solution that can actively, cooperatively, intelligently evaluate low-altitude navigation position credibility and provide hierarchical early warning. Disclosure of Invention Aiming at the problems existing in the prior art, the invention aims to provide a navigation position credible early warning method for eVTOL, logistics transportation, engineering inspection and other low-altitude aircrafts, and a system and a method for carrying out real-time credibility assessment on the positioning result and time delay of an aircraft Global Navigation Satellite System (GNSS) by a multi-source data fusion and collaborative verification technology and carrying out hierarchical early warning when deception, interference or performance degradation is detected. In order to achieve the purpose, the technical scheme adopted by the invention is that the low-altitude navigation position credible early warning method comprises the following steps: step 1, acquiring multi-source cooperative data comprising target aircraft data, foundation enhancement network data and environment perception data through an air-ground safety data chain; Step 2, based on the foundation enhancement network CORS data and the GNSS original observation value of the target aircraft, resolving to obtain a high-precision and high-credibility space reference position and a credible level of a corresponding position, and acquiring external standard time by a comprehensive satellite clock and a time service center; Step 3, collecting and analyzing crowd-sourced GNSS observation data, carrying out signal quality analysis, labeling risks or anomalies, modeling in real time to generate a dynamic quality field, and updating an interference source database; step 4, calculating a plurality of independent credibility factors through parallel channels, and generating multi-dimensional credibility factors by combining the independent credibility factors with the cross verification of the spatial reference position calculated in the step 2; Step 5, inputting the multidimensional credibility factors into a fusion decision engine based on a weight or machine learning model, outputting comprehensive credibility scores, and triggering hierarchical early warning responses according to the comprehensive credibility scores and overrun conditions of each independent credibility factor; and 6, generating a structured early warning message according to the determined early warning response, and distributing the structured early warning message to the target aircraft, the ground control station and the low-altitude traffic control center through a low-altitude communication network. In the low-altitude navigation position credible early warning method, in the step 1, the target aircraft data comprise GNSS original observed values, real-time positions Pu calculated by the aircraft, speeds Vu, time Tu, flight postures and state parameters, and posture angles, air pressure heights and airspeeds from a flight control system; The foundation enhancement network data comprises the reference station state, satellite health s