阅读说明：本技术 高级接收机自主完好性监测保护级优化方法和设备 (Advanced receiver autonomous integrity monitoring protection level optimization method and device ) 是由 薛瑞 赵勇 于 2019-09-24 设计创作，主要内容包括：本发明提供一种高级接收机自主完好性监测保护级优化方法和设备。该方法包括：根据多个卫星的ISM信息计算接收机的全局定位信息以及故障子集的子集定位信息；根据全局定位信息和子集定位信息计算接收机的定位估计误差的分布和故障子集的检测统计量的分布；若确定检测统计量通过检测,则根据最小化完好性风险的优化函数以及定位估计误差的分布和检测统计量的分布,计算优化后的保护级；若根据优化后的保护级判断ARIAM可用,则输出接收机的定位结果。本发明实施例的方法,在非均衡卫星几何分布下对不同的故障子集确定是否通过检测,建立各个卫星故障假设下的完好性目标,以最小化完好性风险为目标,减小由于故障漏检所造成的完好性风险。(The invention provides a method and equipment for optimizing an autonomous integrity monitoring protection level of an advanced receiver. The method comprises the following steps: calculating global positioning information of a receiver and subset positioning information of a fault subset according to ISM information of a plurality of satellites; calculating the distribution of positioning estimation errors of the receiver and the distribution of detection statistics of the fault subsets according to the global positioning information and the subset positioning information; if the detection statistic is determined to pass the detection, calculating the optimized protection level according to the optimization function of the minimized integrity risk, the distribution of the positioning estimation error and the distribution of the detection statistic; and if the ARIAM is judged to be available according to the optimized protection level, outputting the positioning result of the receiver. According to the method provided by the embodiment of the invention, whether different fault subsets pass detection or not is determined under the geometric distribution of the unbalanced satellite, and the integrity target under each satellite fault hypothesis is established, so that the minimized integrity risk is taken as a target, and the integrity risk caused by the missed detection of the fault is reduced.)

1. An advanced receiver autonomous integrity monitoring protection level optimization method is characterized by comprising the following steps:

calculating global positioning information of the receiver and subset positioning information of the fault subset according to the integrity support ISM information of the plurality of satellites;

calculating a positioning estimation error of a receiver and a detection statistic of the fault subset according to the global positioning information and the subset positioning information;

if the detection statistic is determined to pass the detection, calculating an optimized protection level according to an optimization function minimizing the integrity risk, the positioning estimation error of the receiver and the detection statistic of the fault subset;

and if the autonomous integrity monitoring ARIAM of the advanced receiver is available according to the optimized protection level, outputting the positioning result of the receiver.

2. The method of claim 1, wherein computing global positioning information for the receiver based on the integrity support ISM information for the plurality of satellites and subset positioning information for the subset of faults comprises:

calculating a pseudorange covariance matrix for integrity and a pseudorange covariance matrix for precision and continuity according to a ranging error, ranging precision, troposphere error, multipath and user receiver noise included in the ISM information;

and calculating global positioning information of the receiver and subset positioning information of the fault subset by using a weighted least square method according to the pseudo-range covariance matrix for integrity.

3. The method of claim 2, wherein the computing the pseudorange covariance matrix for integrity and the pseudorange covariance matrix for accuracy and continuity from the ranging error, ranging accuracy, tropospheric error, and multipath and user receiver noise included in the ISM information comprises:

calculating a pseudorange covariance matrix according to a ranging error, ranging precision, troposphere error, multipath and user receiver noise in the ISM information by using the following formula (1) and formula (2);

wherein i is 1,2_satRepresents the ith satellite, N_satAs a result of the total number of satellites,

the global positioning information comprises a global positioning solution, and the global positioning information of the receiver is calculated by using a weighted least square method according to the pseudo-range covariance matrix for integrity, wherein the global positioning information comprises the following steps:

the global positioning solution is calculated according to the weighted least squares method using the following formula (3)

Wherein G is N_sat×(3+N_const) Geometric observation matrix of, N_constRepresenting the number of constellations, y being the pseudorange residuals, and the weighting matrix W ═ C_int ^-1(i,i)；

The subset positioning information comprises a subset positioning solution, and the subset positioning information of the fault subset is calculated by using a weighted least square method according to the pseudo-range covariance matrix for integrity, and comprises the following steps:

calculating a subset locator solution for the kth fault subset according to equation (4) below

Wherein, k is 1_{fault_modes}，N_{fault_modes}Indicates the number of fault subsets, W^(k)A weighting matrix for the kth fault subset, wherein

4. The method of claim 3, wherein computing receiver position estimation errors and detection statistics for the faulty subset based on the global positioning information and the subset positioning information comprises:

when the ith satellite fails, positioning estimation is carried outError e of the meter_i' Gaussian distribution subject to non-zero mean, as in equation (5):

ε’_i～N(η_ib_nom,i,(G^TWG)^-1) (5)

wherein the content of the first and second substances,

obtaining detection statistics of the kth fault subset according to the global positioning solution and the subset positioning solution

wherein the content of the first and second substances,

5. the method of claim 4, further comprising:

calculating a threshold of fault detection according to the distribution of the detection statistics;

determining whether the detection statistic passes the detection according to the threshold of the fault detection;

if the detection statistic fails to pass the detection, performing fault elimination until the detection statistic passes the detection;

and if the detection statistic passes the detection, calculating the optimized protection level according to an optimization function of minimizing the integrity risk and the distribution of the positioning estimation error and the detection statistic.

6. The method of claim 5, wherein computing a threshold for fault detection based on the distribution of the detection statistics comprises

The threshold T for fault detection is calculated using equation (7)_k：

Wherein, beta_kRepresents H₀Detection alarm rate P (| Δ x) under assumption^(k)|≥T_k|H₀)，H₀The assumption that all the stars are visible is represented,

7. The method of claim 5, wherein the protection stage comprises: a vertical protection level, calculating an optimized protection level, comprising:

solving the vertical protection level that minimizes the optimization function of the integrity risk as the optimized vertical protection level using the following equation (8):

wherein r ═ G^TWG)^-1，_{Nfault_modes}Indicates the number of subsets of faults,

8. The method of claim 7, wherein solving the vertical protection level that minimizes the optimization function of the integrity risk using the following equation (8) as the optimized vertical protection level comprises:

respectively for η in formula (9)_i,

9. The method of claim 7, wherein prior to outputting the receiver positioning result, further comprising:

if the optimized vertical protection level is smaller than a preset vertical warning limit VAL, ARAIM is available;

if the optimized vertical protection level is greater than the VAL, the ARIAM is unavailable.

10. An advanced receiver autonomous integrity monitoring protection level optimization device, comprising:

a processor; and

a memory for storing executable instructions of the processor;

wherein the processor is configured to perform the method of any of claims 1-9 via execution of the executable instructions.

Technical Field

The invention relates to the technical field of aviation monitoring, in particular to an advanced receiver autonomous integrity monitoring protection level optimization method and device.

Background

With the wide application of a Global Navigation Satellite System (GNSS), users have increasingly high requirements for GNSS Navigation safety and integrity, and in Performance indexes of a precision Navigation technology (RNP), the integrity is directly related to aviation safety, and the integrity refers to the capability of the System to give an alarm to the users in time when Navigation errors exceed an upper limit allowed by safe operation. The GNSS navigation signal is a modulation wave for navigation positioning broadcasted by GNSS to a user, and the signal is affected by various factors in the process of propagation to generate errors, such as satellite clock error, satellite ephemeris error, ionospheric delay, tropospheric delay, multipath, receiver noise and the like, and the errors are superposed at a user end to cause pseudo-range errors.

In the existing Advanced Receiver autonomous integrity Monitoring (Advanced Receiver autonomous integrity Monitoring, referred to as "ARAIM"), a Multiple failure hypothesis Separation (MHSS) algorithm is mainly used, satellite failure detection and failure identification are respectively provided on the basis of uniform geometric distribution of fully visible satellites, a positioning solution of the fully visible satellites is defined in the algorithm as a global positioning solution, a subset positioning solution is a positioning solution of the fully visible satellites excluding one or more satellites, and the basic principle is that the fully visible satellites are used as a reference, then the distance between each subset positioning solution and the global positioning solution is calculated, and whether a failure exists is judged by comparing the distance with a threshold value. The algorithm considers that in the absence of a fault, the global positioning solution and all subset positioning solutions should be clustered together, whereas if a faulty satellite is present, the global positioning solution and the subset positioning solution using the faulty satellite will produce an offset, and the subset positioning solution without the faulty satellite will be closer to the true position of the aircraft.

However, in practical applications, especially when the visible number of satellites is small, the geometric distribution of the satellites is unbalanced, so that misarrangement and missing arrangement of the failed satellites are caused, dangerous misleading information is formed, and the integrity of autonomous integrity monitoring of the advanced receiver is affected.

Disclosure of Invention

The invention provides an advanced receiver autonomous integrity monitoring protection level optimization method and equipment, which are used for reducing integrity risks caused by fault omission.

In a first aspect, the present invention provides an advanced receiver autonomous integrity monitoring protection level optimization method, including:

calculating global positioning information of the receiver and subset positioning information of the fault subset according to the integrity support ISM information of the plurality of satellites;

calculating a positioning estimation error of a receiver and a detection statistic of the fault subset according to the global positioning information and the subset positioning information;

if the detection statistic is determined to pass the detection, calculating an optimized protection level according to an optimization function minimizing the integrity risk, the positioning estimation error of the receiver and the detection statistic of the fault subset;

and if the autonomous integrity monitoring ARIAM of the advanced receiver is available according to the optimized protection level, outputting the positioning result of the receiver.

In a second aspect, the present invention provides an advanced receiver autonomous integrity monitoring protection level optimization device, comprising:

a processor; and

a memory for storing executable instructions of the processor;

wherein the processor is configured to perform the method of any of the first aspects via execution of the executable instructions.

According to the method and the equipment for optimizing the autonomous integrity monitoring protection level of the advanced receiver, the global positioning information of the receiver and the subset positioning information of the fault subset are calculated according to the integrity support ISM information of a plurality of satellites; calculating a positioning estimation error of a receiver and a detection statistic of the fault subset according to the global positioning information and the subset positioning information; if the detection statistic is determined to pass the detection, calculating an optimized protection level according to an optimization function minimizing the integrity risk, the positioning estimation error of the receiver and the detection statistic of the fault subset; and if the autonomous integrity monitoring ARIAM of the advanced receiver is available according to the optimized protection level, outputting a positioning result of the receiver, and particularly under the condition of non-equilibrium satellite geometric distribution, determining whether the detection is passed or not by different fault subsets, and then establishing integrity targets under the assumption of each satellite fault to take the minimized integrity risk as a target, thereby reducing the integrity risk caused by fault omission and ensuring the aviation flight safety.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and together with the description, serve to explain the principles of the disclosure.

FIG. 1 is a schematic diagram of the geometric distribution of non-equilibrium satellites provided by the present invention;

FIG. 2 is a flow chart illustrating an embodiment of a method for optimizing the protection level of the advanced receiver autonomous integrity monitoring provided by the present invention;

fig. 3 is a schematic structural diagram of an embodiment of the advanced receiver autonomous integrity monitoring protection level optimizing device provided in the present invention.

With the foregoing drawings in mind, certain embodiments of the disclosure have been shown and described in more detail below. These drawings and written description are not intended to limit the scope of the disclosed concepts in any way, but rather to illustrate the concepts of the disclosure to those skilled in the art by reference to specific embodiments.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the exemplary embodiments below are not intended to represent all implementations consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present disclosure, as detailed in the appended claims.