KR20220103553A - Apparatus and method for screening doppler measurement fault, and apparatus and method for detecting gnss measurement fault - Google Patents

Abstract

The present application relates to a device and method for screening a Doppler measurement value, and to a device and method for detecting a fault of a GNSS measurement value using the same. According to one embodiment of the present application, the device for screening a Doppler measurement value may include: a receiving unit which receives speed information measured and transmitted by the INS from a moving object and receives GNSS raw data received from a plurality of satellites by a GNSS receiver; a calculation unit which calculates a Doppler measurement value based on the GNSS raw data and calculates a Doppler prediction value based on the speed information and the GNSS raw data; and a determination unit which selects an abnormal Doppler measurement value including an error in consideration of a difference between the measured Doppler value and the predicted Doppler value.

Description

Apparatus and method for screening Doppler measurements, and apparatus and method for detecting failure of GNSS measurements using the same

The present application relates to a Doppler measurement value screening apparatus and method, and a GNSS measurement failure detection apparatus and method using the same.

Recently, research on autonomous driving systems is being actively conducted, and in securing the safety of the autonomous driving system, it is an essential element to acquire accurate location information of moving objects, such as vehicles, in real time.

GNSS (Satellite Positioning System, Global Navigation Satellite System) can obtain the position and speed of a moving object by receiving signals from satellites at an altitude of about 20,000 km to 35,000 km. In downtown areas where there are many obstacles in can

INS (Inertial Navigation System), LiDAR (Light Detection and Ranging), Odometer (Odometer) Global Positioning System (GPS)/Inertial Navigation System (INS) combination method, GPS/INS/Light Detection And Ranging (LiDAR) combination method, and GPS /INS/Odometer/Vision combination technique and others have been studied.

In particular, techniques for effectively detecting multipath errors for each channel without special requirements have been studied, and among them, methods for detecting cycle slip and multipath errors based on Doppler measurements are widely used. That is, in order to detect a GNSS measurement value including an error, a detection technique based on a Doppler measurement value having a characteristic robust to error among GNSS measurement values is widely used.

However, if an error is included in the Doppler measurement, which is the reference for detecting cycle slip and multipath error, the cycle slip and multipath error cannot be accurately detected, so the detector can no longer function properly. there is a problem.

The technology that is the background of the present application is disclosed in Korean Patent No. 10-0443550.

In order to solve the problems of the prior art described above, the present application calculates a Doppler predicted value using velocity information received from an INS, and calculates a Doppler measurement value using GNSS raw data received from a GNSS receiver, thereby calculating the Doppler predicted value and Doppler An object of the present invention is to provide an apparatus and method for selecting a Doppler measurement value capable of selecting a Doppler measurement value due to an error using the measurement value, and an apparatus and method for detecting a GNSS measurement value failure using the same.

In addition, in order to solve the above-mentioned problems of the prior art, the position, speed, etc. of a moving object can be accurately measured by selecting an abnormal Doppler measurement value due to an error from among the Doppler measurement values serving as a reference for detecting cycle slip and multipath errors. An object of the present invention is to provide an apparatus and method for selecting a Doppler measurement value, and an apparatus and method for detecting a failure of a GNSS measurement value using the same.

However, the technical problems to be achieved by the embodiment of the present application are not limited to the technical problems as described above, and other technical problems may exist.

As a technical means for achieving the above technical problem, the Doppler measurement value screening apparatus according to an embodiment of the present application receives velocity information measured and transmitted by the INS by a mobile body, and GNSS raw data received by the GNSS receiver from a plurality of satellites A receiving unit receiving the GNSS raw data, calculating a Doppler measurement value based on the GNSS raw data, and a calculating unit calculating a Doppler predicted value based on the velocity information and the GNSS raw data Considering the difference between the Doppler measurement value and the Doppler prediction value, It may include a determination unit that selects an abnormal Doppler measurement value including an error.

The speed information of the apparatus for selecting a Doppler measurement value according to an embodiment of the present application may be obtained based on an inertial sensor provided in a moving object.

In the Doppler measurement value screening apparatus according to an embodiment of the present application, in the calculator, the Doppler measurement value is calculated by Equation 1 below,

[Equation 1]

는 j번째 위성에 대한 도플러 측정치,

와

는 각각 j번째 위성에 대하여 수신, 송신된 주파수인 것이고, 상기 도플러 예측치는 하기 식 2에 의해 산출되고, In Equation 1 above

is the Doppler measurement for the j -th satellite,

Wow

is a frequency received and transmitted with respect to the j -th satellite, respectively, and the Doppler prediction value is calculated by Equation 2 below,

[Equation 2]

는 상기 도플러 예측치,

는 j번째 위성에 대하여 송신된 주파수,

는 빛의 속도,

는 j번째 위성에 대한 시선각 벡터,

는 ECEF(Earth-Centered Earth-Fixed) 좌표계에서 정의된 j번째 위성의 속도,

는 ECEF 좌표계에서 정의된 이동체의 속도인 것일 수 있다.In Equation 2 above

is the Doppler predicted value,

is the frequency transmitted for the j -th satellite,

is the speed of light,

is the line-of-sight vector for the j -th satellite,

is the velocity of the j-th satellite defined in the ECEF (Earth-Centered Earth-Fixed) coordinate system,

may be the velocity of the moving object defined in the ECEF coordinate system.

The determination unit of the apparatus for selecting a Doppler measurement value according to an embodiment of the present application may select the Doppler measurement value as the abnormal Doppler measurement value when the magnitude of the difference between the Doppler measurement value and the Doppler predicted value exceeds a threshold value.

A GNSS measurement failure detection apparatus according to an embodiment of the present application includes an INS for measuring speed information in a moving object, a GNSS receiver for receiving GNSS raw data from a plurality of satellites, the Doppler measurement value selection device, and a carrier wave measured from the GNSS raw data A cycle slip detector that detects cycle slip in consideration of the difference between the phase measurement increment and the Doppler measurement excluding the abnormal Doppler measurement, and the difference between the pseudorange measurement increment measured from the GNSS raw data and the Doppler measurement excluding the abnormal Doppler measurement It may include a multipath error detection unit that detects a multipath error in consideration of

The speed information of the GNSS measurement failure detection apparatus according to an embodiment of the present application may be obtained based on an inertial sensor provided in a moving object.

The calculation unit of the GNSS measurement value failure detection apparatus according to an embodiment of the present application calculates the Doppler measurement value by Equation 3 below,

[Equation 3]

는 j번째 위성에 대한 도플러 측정치,

와

는 각각 j번째 위성에 대하여 수신, 송신된 주파수인 것이고, 상기 도플러 예측치를 하기 식 4에 의해 산출하고,In Equation 3 above

is the Doppler measurement for the j -th satellite,

Wow

is a frequency received and transmitted to the j -th satellite, respectively, and the Doppler predicted value is calculated by Equation 4 below,

[Equation 4]

는 상기 도플러 예측치,

는 j번째 위성에 대하여 송신된 주파수,

는 빛의 속도,

는 j번째 위성에 대한 시선각 벡터,

는 ECEF(Earth-Centered Earth-Fixed) 좌표계에서 정의된 j번째 위성의 속도,

는 ECEF 좌표계에서 정의된 이동체의 속도인 것일 수 있다.In Equation 4 above

is the Doppler predicted value,

is the frequency transmitted for the j -th satellite,

is the speed of light,

is the line-of-sight vector for the j -th satellite,

is the velocity of the j-th satellite defined in the ECEF (Earth-Centered Earth-Fixed) coordinate system,

may be the velocity of the moving object defined in the ECEF coordinate system.

The determination unit of the GNSS measurement failure detection apparatus according to an embodiment of the present application may select the Doppler measurement value as the abnormal Doppler measurement value when the magnitude of the difference between the Doppler measurement value and the Doppler predicted value exceeds a threshold value. .

The GNSS measurement failure detection apparatus according to an exemplary embodiment of the present disclosure may include an update unit that updates the position and speed of the moving object based on the detection results of the cycle slip detection unit and the multipath error detection unit.

The Doppler measurement value selection method according to an embodiment of the present application includes the steps of (a) receiving speed information measured and transmitted by an INS from a mobile body, and receiving, by a GNSS receiver, raw GNSS data received from a plurality of satellites, (b) the above calculating a Doppler measurement value based on the GNSS raw data, calculating a Doppler prediction value based on the velocity information and the GNSS raw data, and (c) taking into account the difference between the Doppler measurement value and the Doppler prediction value, including an error It may include screening for anomalous Doppler measurements.

In the Doppler measurement value screening method according to an embodiment of the present application, in step (b), the Doppler measurement value is calculated by Equation 5 below,

[Equation 5]

는 j번째 위성에 대한 도플러 측정치,

와

는 각각 j번째 위성에 대하여 수신, 송신된 주파수인 것이고, 상기 도플러 예측치는 하기 식 6에 의해 산출되고,In Equation 5 above

is the Doppler measurement for the j -th satellite,

Wow

is a frequency received and transmitted for the j -th satellite, respectively, and the Doppler prediction value is calculated by Equation 6 below,

[Equation 6]

는 상기 도플러 예측치,

는 j번째 위성에 대하여 송신된 주파수,

는 빛의 속도,

는 j번째 위성에 대한 시선각 벡터,

는 ECEF(Earth-Centered Earth-Fixed) 좌표계에서 정의된 j번째 위성의 속도,

는 ECEF 좌표계에서 정의된 이동체의 속도인 것일 수 있다.In Equation 6 above

is the Doppler predicted value,

is the frequency transmitted for the j -th satellite,

is the speed of light,

is the line-of-sight vector for the j -th satellite,

is the velocity of the j-th satellite defined in the ECEF (Earth-Centered Earth-Fixed) coordinate system,

may be the velocity of the moving object defined in the ECEF coordinate system.

The step (c) of the Doppler measurement value selection method according to an embodiment of the present application is to select the Doppler measurement value as the abnormal Doppler measurement value when the magnitude of the difference between the Doppler measurement value and the Doppler predicted value exceeds a threshold value can

A GNSS measurement failure detection method according to an embodiment of the present application includes the steps of (d) measuring speed information in a mobile body by an INS, (e) receiving, by a GNSS receiver, GNSS raw data from a plurality of satellites, (f) the above selecting the anomalous Doppler measurement according to a screening method for the Doppler measurement; (g) detecting a cycle slip by considering the difference between the carrier phase measurement increment measured from the GNSS raw data and the Doppler measurement excluding the anomalous Doppler measurement. and (h) detecting a multipath error in consideration of a difference between the increment of the pseudorange measurement value measured from the GNSS raw data and the Doppler measurement value excluding the abnormal Doppler measurement value.

In the step (b) of the GNSS measurement failure detection method according to an embodiment of the present application, the Doppler measurement value is calculated by Equation 7 below,

[Equation 7]

는 j번째 위성에 대한 도플러 측정치,

와

는 각각 j번째 위성에 대하여 수신, 송신된 주파수인 것이고, 상기 도플러 예측치를 하기 식 8에 의해 산출하고,In Equation 7 above

is the Doppler measurement for the j -th satellite,

Wow

is the received and transmitted frequencies for the j -th satellite, respectively, and the Doppler predicted value is calculated by the following Equation 8,

[Equation 8]

는 상기 도플러 예측치,

는 j번째 위성에 대하여 송신된 주파수,

는 빛의 속도,

는 j번째 위성에 대한 시선각 벡터,

는 ECEF(Earth-Centered Earth-Fixed) 좌표계에서 정의된 j번째 위성의 속도,

는 ECEF 좌표계에서 정의된 이동체의 속도인 것일 수 있다. In Equation 8 above

is the Doppler predicted value,

is the frequency transmitted for the j -th satellite,

is the speed of light,

is the line-of-sight vector for the j -th satellite,

is the velocity of the j-th satellite defined in the ECEF (Earth-Centered Earth-Fixed) coordinate system,

may be the velocity of the moving object defined in the ECEF coordinate system.

The above-described problem solving means are merely exemplary, and should not be construed as limiting the present application. In addition to the exemplary embodiments described above, additional embodiments may exist in the drawings and detailed description.

According to the above-described problem solving means of the present application, the Doppler measurement value selection apparatus and method, the Doppler predicted value calculated using velocity information through the GNSS measurement value failure detection apparatus and method using the same, and the Doppler measurement value calculated using the GNSS raw data are used Thus, it is possible to select and isolate anomaly Doppler measurements due to errors.

In addition, according to the above-described problem solving means of the present application, the abnormal Doppler measurement value among the Doppler measurement values serving as a reference for detecting cycle slip and multipath error through the Doppler measurement value selection apparatus and method, and the GNSS measurement value failure detection apparatus and method using the same By sorting and isolating, it is possible to accurately measure the position and speed of a moving object.

However, the effects obtainable herein are not limited to the above-described effects, and other effects may exist.

1 is a diagram illustrating a GNSS measurement failure detection system according to an embodiment of the present application.
2 is a simplified operation flowchart of a GNSS measurement failure detection apparatus according to an embodiment of the present application.
3 is a diagram illustrating a difference between a Doppler measurement value and a Doppler predicted value according to an embodiment of the present application.
4 is a diagram illustrating a difference between a Doppler measurement value and a carrier phase measurement value increment using a GNSS measurement value failure detection apparatus according to a conventional method and an embodiment of the present application.
5 is a diagram illustrating a difference between an increment of a pseudorange measurement value and a Doppler measurement value using the GNSS measurement failure detection apparatus according to the conventional method and an embodiment of the present application.
6 is a diagram illustrating a measurement environment using a GNSS measurement value failure detection apparatus according to an embodiment of the present application.
7 is a diagram illustrating a difference between a Doppler measurement value and a Doppler predicted value calculated using the GNSS measurement value failure detection apparatus according to an embodiment of the present application in the measurement environment of FIG. 6 .
8 to 13 show the measurement results and the position measurement results of the moving object according to the conventional method for the abnormal point 1 to the abnormal point 6 in FIG. It is a diagram showing the position measurement result of
14 is a schematic configuration diagram of an apparatus for selecting a Doppler measurement value and an apparatus for detecting a failure of a GNSS measurement value according to an embodiment of the present application.
15 is an operation flowchart of a method for selecting a Doppler measurement value according to an embodiment of the present application.
16 is an operation flowchart of a GNSS measurement failure detection method according to an embodiment of the present application.

Hereinafter, embodiments of the present application will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art to which the present application pertains can easily implement them. However, the present application may be implemented in several different forms and is not limited to the embodiments described herein. And in order to clearly explain the present application in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout this specification, when a part is said to be "connected" with another part, it includes not only the case where it is "directly connected" but also the case where it is "electrically connected" with another element interposed therebetween. do.

Throughout this specification, when it is said that a member is positioned "on", "on", "on", "under", "under", or "under" another member, this means that a member is located on the other member. It includes not only the case where they are in contact, but also the case where another member exists between two members.

Throughout this specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be construed in an ideal or overly formal meaning unless explicitly defined herein. do.

The suffixes “module,” “block,” and “part” for the components used in the following description are given or mixed in consideration of the ease of writing the specification only, and do not have distinct meanings or roles by themselves. .

In the conventional GNSS measurement value detection technique, a measurement value including an error is detected through comparison between the GNSS measurement values. In the above-mentioned techniques, if an error occurs in the measurement value at the same time or a sudden change in the external environment occurs, the detection function is significantly deteriorated. In addition, an expensive GNSS receiver is also required.

The Doppler measurement value selection apparatus 100 or the GNSS measurement value failure detection apparatus 200 according to an embodiment of the present application determines whether an error is included in the GNSS measurement value by using speed information provided from the INS having a characteristic that is not affected by the outside. can judge It can also be applied to low-cost GNSS receivers and inertial sensors.

The Doppler measurement value selection apparatus 100 or the GNSS measurement failure detection apparatus 200 according to an embodiment of the present application is an essential technology for accurate location estimation in a downtown area, and the Doppler measurement value selection apparatus 100 and method disclosed herein And the GNSS measurement value failure detection apparatus 200 and method using the same can be utilized to more accurately determine the position and speed of a moving object in an autonomous driving system or the like. In addition, accurate location information estimated by applying the Doppler measurement value selection device 100 or the GNSS measurement value failure detection device 200 can be applied and applied to various fields such as geodetic/surveying and bridge monitoring.

The Doppler measurement value selection apparatus 100 or the GNSS measurement failure detection apparatus 200 according to an embodiment of the present application includes a device for detecting a measurement value including an error among a plurality of measurement values obtained from multiple global navigation satellite systems (GNSS); it's about how In the vicinity of the earth's surface, the strength of the GNSS signal is very weak, so that the signal is blocked or a reflected signal is received in a downtown area with many obstacles, which frequently causes a large positioning error. In order to detect GNSS measurements, a detection technique based on Doppler measurements having a characteristic robust to errors among GNSS measurements is widely used. However, when an error is included in the Doppler measurement, which is the reference in the conventional technique, the detector can no longer function properly.

The GNSS measurements may include, for example, carrier phase measurements, pseudorange measurements, Doppler measurements, and the like. Carrier phase measurement has low noise, so precise position estimation is possible, and unspecified determination is required. The carrier phase measurement may occur when a signal disconnection phenomenon due to cycle slip occurs, or when the tracking of the carrier phase locked loop (PLL) in the receiver is temporarily stopped. Cycle slip can be caused by signal drops, high signal noise, low signal strength, receiver failure, clock errors, ionospheric effects, etc., and can cause abrupt changes in carrier phase measurements.

Among GNSS measurements, pseudorange measurements provide absolute distance information, but are noisy, and are based on the time it takes for a signal transmitted from a satellite to reach the receiver. Pseudo-range measurements are vulnerable to multipath errors, and when a signal reflected by an obstacle is received, the arrival time becomes longer, and errors may be included in the generated pseudo-range measurements.

Among GNSS measurements, the Doppler measurement (Doppler shift measurement) can be caused by the relative motion of the satellite and the receiver, provides a rate of change of distance, has relatively low noise, has robust characteristics against multipath error, and does not cause signal breakage. There is a characteristic. Therefore, a technique using a Doppler measurement value having robust characteristics as a reference for detecting cycle slip or multipath error is widely used.

The Doppler measurement value selection apparatus 100 or the GNSS measurement value selection failure detection apparatus 200 disclosed herein utilizes the velocity information provided by the INS (Inertial Navigation System) that is not influenced by the outside to first select the Doppler measurement value, , The GNSS measurement value failure detection apparatus 200 may detect the GNSS measurement value including the error after selecting the Doppler measurement value. The GNSS measurement failure detection may also be understood as a concept of monitoring the integrity of the GNSS measurement values (GNSS Integrity Monitoring).

1 is a diagram illustrating a GNSS measurement failure detection system 10 according to an embodiment of the present application.

Referring to FIG. 1 , a GNSS measurement failure detection system 10 according to an embodiment of the present application may include a GNSS measurement failure detection apparatus 200 , a plurality of satellites 400 , and an inertial sensor 300 . The GNSS measurement failure detection device 200 of the GNSS measurement failure detection system 10 may receive GNSS raw data from a plurality of satellites, and an inertial sensor 300 (or inertial measurement equipment, IMU, The speed information of the moving object can be generated by receiving the current speed, rotational speed, direction, inclination, and acceleration of the moving object from the Inertial Measurement Unit). The GNSS measurement failure detection apparatus 200 may calculate a Doppler measurement value and a Doppler predicted value using the GNSS raw data and velocity information, and a Doppler measurement value including an error using the calculated Doppler measurement value and the Doppler prediction value, that is, an abnormal Doppler measurement value can be selected (detected). The Doppler measurement value screening device 100 of the GNSS measurement failure detection system 10 The GNSS measurement failure detection apparatus 200 detects cycle slip and multipath errors based on the Doppler measurement values excluding the abnormal Doppler measurement value including the error among the Doppler measurement values. Thus, it is possible to measure (or estimate) the position, velocity, or position of the moving object.

That is, the GNSS measurement failure detection apparatus 200 according to an embodiment of the present application includes GNSS data acquisition, inertial sensor data acquisition, GNSS Doppler measurement detection, cycle slip detection, and multipath error detection, for example. The INS 110 of FIG. 1 , the GNSS receiver 120 , the Doppler measurement value selection device 100 , the cycle slip detector 160 , the multipath error detector 170 , and the like may be included. The GNSS measurement failure detection apparatus 200 may effectively detect a Doppler measurement value including an error (in other words, an abnormal Doppler measurement value) by using the INS 110 that is not affected by the external environment. In addition, cycle slip and multipath error can be detected using selected Doppler measurements, and it can be applied to low-cost single GNSS antennas and receivers and inertial sensors, and efficient detection is possible with simple algorithms and methods.

Referring to FIG. 1 , a plurality of satellites according to an embodiment of the present application may include a GPS satellite, a GLONASS satellite, a BeiDou satellite, a Galileo satellite, and the like. The GNSS measurement failure detection apparatus 200 of the GNSS measurement failure detection system 10 may receive respective signals from a plurality of satellites, that is, a GPS signal, a GLONASS signal, a BeiDou signal, a Galileo signal, and the like, and receive GNSS raw data. can do.

Referring to FIG. 1 , a GNSS measurement failure detection apparatus 200 according to an embodiment of the present application includes a Doppler measurement value selection apparatus 100 , an INS 110 , a GNSS receiver 120 , a cycle slip detection unit 160 , and a multipath. It may include an error detection unit 170 .

In addition, referring to FIG. 1 , the Doppler measurement value screening apparatus 100 according to an embodiment of the present application receives speed information measured and transmitted by the INS 110 by a mobile body, and the GNSS receiver 120 receives the plurality of satellites ( Receiver 130 for receiving the GNSS raw data received from 400). The calculation unit 140 that calculates a Doppler measurement value based on GNSS raw data and calculates a Doppler predicted value based on velocity information and GNSS raw data, and an abnormal Doppler measurement value including an error in consideration of the difference between the Doppler measurement value and the Doppler predicted value It may include a determination unit 150 for selecting the.

The receiver 130 may receive speed information measured and transmitted by the INS 110 by the mobile body, and the GNSS raw data received by the GNSS receiver 120 from a plurality of satellites 400 may be transmitted. The GNSS receiver 120 may receive GNSS raw data such as a GPS signal, a GLONASS signal, a BeiDou signal, and a Galileo signal from each of the plurality of satellites 400 , and transmit it to the receiver 130 . The INS 110 (inertial navigation device or inertial navigation system) may transmit speed information measured by the moving object to the receiver 130 .

The speed information according to an embodiment of the present application may be obtained based on the inertial sensor 300 provided in the moving object. The inertial sensor 300 (or inertial measuring equipment, IMU) may be attached to a moving object, and may measure a current speed, rotational speed, direction, inclination, and acceleration of the moving object. The INS 110 may receive each axis of the moving object measured from the inertial sensor 300 , for example, x, y, and z-axis speed, rotation speed, direction, inclination, acceleration, and the like. In addition, the INS 110 may receive a gyro measurement value, an accelerometer measurement value, etc. measured from the inertial sensor 300 , and may measure speed information of the moving object.

The calculator 140 may calculate a Doppler measurement value based on the GNSS raw data, and may calculate a Doppler predicted value based on the velocity information and the GNSS raw data. The Doppler measurement value is calculated based on GNSS raw data, and may be calculated using frequencies of signals received and transmitted with respect to the satellite according to the Doppler effect (or Doppler shift). The Doppler prediction value is calculated based on velocity information and GNSS raw data. The frequency transmitted to the satellite, the speed of light, the line-of-sight vector for the satellite, and the velocity of the satellite defined in the ECEF (Earth-Centered Earth-Fixed) coordinate system. And it may be calculated based on the speed of the moving object.

In the calculator 140 of the apparatus 100 for selecting a Doppler measurement value according to an embodiment of the present application, the Doppler measurement value may be calculated by Equation 1 below, and the Doppler predicted value may be calculated by Equation 2 below. Equations 1 and 2 below may be understood as modeling a Doppler measurement value and a Doppler prediction value (predicted Doppler measurement value) for the j -th satellite.

,

)는 이동체 및 위성의 운동에 의한 도플러 효과에 의하여 차이가 발생할 수 있고, 아래 수학식 1과 같이 복수의 위성(400) 중 j번째 위성에 대한 도플러 측정치

를 산출할 수 있다.The calculator 140 may calculate a Doppler measurement value for the j -th satellite among the plurality of satellites 400 by using the GNSS raw data received from the plurality of satellites 400 . For the j -th satellite, the frequency of the received signal and the frequency of the transmitted signal (

,

) may be different due to the Doppler effect caused by the motion of the moving object and the satellite, and as shown in Equation 1 below, a Doppler measurement value for the j -th satellite among the plurality of satellites 400

can be calculated.

[Equation 1]

는 j번째 위성에 대한 도플러 측정치,

와

는 각각 (복수의 위성 중에서) j번째 위성에 대하여 수신, 송신된 주파수(즉, j번째 위성에 대하여 수신, 송신된 신호의 주파수)이다.In Equation 1 above

is the Doppler measurement for the j -th satellite,

Wow

is the received and transmitted frequencies (ie, frequencies of signals received and transmitted with respect to the j -th satellite) for the j -th satellite, respectively (from among the plurality of satellites).

The calculator 140 may calculate a Doppler predicted value for the j -th satellite among the plurality of satellites 400 by using the GNSS raw data received from the plurality of satellites 400 and the velocity information received from the INS 110 . . The Doppler effect (or Doppler shift, Doppler phenomenon) refers to a phenomenon in which the frequency and wavelength change according to the relative speed of the wave source and the observer (or moving object, user) of a wave, and the relative motion of the moving object and the satellite, that is, Depending on the relative speed, the frequency (or the frequency of the signal) transmitted from the j -th satellite may be affected.

, 빛의 속도

, j번째 위성에 대한 시선각 벡터(LOS 벡터, Line of Sight Vector)

, ECEF(Earth-Centered Earth-Fixed) 좌표계에서 정의된 j번째 위성의 속도

, ECEF 좌표계에서 정의된 이동체의 속도

를 이용하여 도플러 예측치

를 구할 수 있다. Therefore, if the change (shift) of the frequency according to the relative motion (or relative speed) of the moving object-satellite is modeled, it can be modeled as in Equation 2 below. Using Equation 2 below, which is modeled according to the relative motion of the moving object and the satellite, the frequency transmitted to the j -th satellite

, Speed of light

, the line of sight vector for the j -th satellite (LOS vector, Line of Sight Vector)

, the velocity of the j-th satellite as defined in the ECEF (Earth-Centered Earth-Fixed) coordinate system.

, the velocity of the moving object defined in the ECEF coordinate system.

Doppler prediction using

can be obtained

[Equation 2]

는 상기 도플러 예측치,

는 j번째 위성에 대하여 송신된 주파수,

는 빛의 속도,

는 j번째 위성에 대한 시선각 벡터,

는 ECEF(Earth-Centered Earth-Fixed) 좌표계에서 정의된 j번째 위성의 속도,

는 ECEF 좌표계에서 정의된 이동체의 속도이다.In Equation 2 above

is the Doppler predicted value,

is the frequency transmitted for the j -th satellite,

is the speed of light,

is the line-of-sight vector for the j -th satellite,

is the velocity of the j -th satellite as defined in the ECEF (Earth-Centered Earth-Fixed) coordinate system,

is the velocity of the moving object defined in the ECEF coordinate system.

는 j번째 위성의 위치 좌표와 사용자(또는 수신기, 이동체)의 위치 좌표를 이용하여 얻을 수 있다. 예를 들어, 시선각 벡터

는 j번째 위성의 위치 좌표에서 사용자(또는 수신기, 이동체)의 위치 좌표를 뺄셈하여 얻을 수 있다. ECEF 좌표계에서 정의된 j번째 위성의 속도

는 위성에서 송신된 GNSS 항법 메시지(또는 GNSS 원시 데이터) 내의 파라미터를 활용하여 계산(산출, 생성)될 수 있다.In Equation 2, the viewing angle vector for the j -th satellite

can be obtained by using the position coordinates of the j -th satellite and the position coordinates of the user (or receiver, mobile body). For example, the viewing angle vector

can be obtained by subtracting the position coordinates of the user (or receiver, mobile body) from the position coordinates of the j -th satellite. Velocity of the j -th satellite as defined in the ECEF coordinate system

may be calculated (calculated, generated) using parameters in a GNSS navigation message (or GNSS raw data) transmitted from a satellite.

를 산출하기 위하여 필요한 값들인 j번째 위성에 대하여 송신된 주파수

, 빛의 속도

, j번째 위성에 대한 시선각 벡터

, ECEF 좌표계에서 정의된 j번째 위성의 속도

, ECEF 좌표계에서 정의된 이동체의 속도

는, GNSS 수신기(120)로부터 수신한 GNSS 원시 데이터, INS(110)로부터 수신한 이동체(또는 사용자)의 속도 정보를 이용하여 산출(계산, 획득)될 수 있다. 즉, 산출부(140)는 복수의 위성(400)으로부터 수신한 GNSS 원시 데이터(또는 GNSS 항법 메시지) 및 INS(110)로부터 전달받은 속도 정보를 이용하여 복수의 위성(400) 중 j번째 위성에 대한 도플러 예측치를 산출할 수 있다.Doppler predicted value in Equation 2 above

The frequency transmitted for the j -th satellite, which is the values necessary to calculate

, Speed of light

, the line-of-sight vector for the j -th satellite

, the velocity of the j-th satellite defined in the ECEF coordinate system.

, the velocity of the moving object defined in the ECEF coordinate system.

, may be calculated (calculated, obtained) using the GNSS raw data received from the GNSS receiver 120 and speed information of the moving object (or user) received from the INS 110 . That is, the calculator 140 uses the GNSS raw data (or GNSS navigation message) received from the plurality of satellites 400 and the speed information received from the INS 110 to the j -th satellite among the plurality of satellites 400 . It is possible to calculate a Doppler predicted value for

The determination unit 150 may select an abnormal Doppler measurement value including an error in consideration of a difference between the Doppler measurement value and the Doppler predicted value. Since the Doppler measurement value is calculated using the GNSS raw data, and the Doppler prediction value is calculated in consideration of the velocity information received from the INS 110 , when the error included in the GNSS raw data received from the satellite increases, the Doppler measurement value The difference between and Doppler predictions may be large.

That is, the determination unit 150 may select an abnormal Doppler measurement value including an error by using (considering) the difference between the Doppler measurement value and the Doppler predicted value, and GNSS raw data (or satellite, satellite) corresponding to the selected abnormal Doppler measurement value. channel) may be determined as including an error. For example, if the difference between the Doppler measurement value and the Doppler prediction value measured from the j -th satellite is large, it may be determined that the GNSS raw data received from the j -th satellite includes an error.

In addition, the determination unit 150 selects and isolates (separates) GNSS raw data (or satellite, satellite channel) corresponding to the selected abnormal Doppler measurement value, and calculates and updates the position, velocity, location, etc. of the moving object. can be isolated from In other words, isolating may mean isolating the j -th satellite that transmitted the GNSS raw data from which the anomalous Doppler measurement was screened, or isolating the GNSS raw data from which the anomalous Doppler measurement was screened, the GNSS raw data received from the isolated satellite The data is selected as including an error and is not considered in the subsequent process of calculating the position, speed, etc. of the moving object, and means using the GNSS raw data received from the remaining satellites except for the isolated satellite among the plurality of satellites 400. can Accordingly, the determination unit 150 may select an abnormal Doppler measurement value and isolate a satellite or satellite channel corresponding to the abnormal Doppler measurement value.

When the calculated Doppler measurement value is selected as an abnormal Doppler measurement value according to the difference between the Doppler measurement value calculated using the GNSS raw data measured from the j -th satellite among the plurality of satellites 400 and the Doppler prediction value calculated in consideration of velocity information Isolate the GNSS raw data (or j -th satellite, j -th satellite channel) measured from the j -th satellite, and save the GNSS raw data received from other satellites except for the GNSS raw data received from the j -th satellite selected by anomaly Doppler measurement. It can be used to calculate the speed, position, position, etc. of the moving object. In other words, the Doppler measurement value and the Doppler prediction value are used to determine whether the Doppler measurement is an abnormal Doppler measurement including an error, and if the Doppler measurement is an abnormal Doppler measurement, the GNSS raw data corresponding to the abnormal Doppler measurement includes an error The corresponding GNSS raw data (or satellites, satellite channels) can be screened, isolated and blocked.

Summarizing the above, although Doppler measurements have robust characteristics, errors may occur in urban areas due to obstacles. The determination unit 150 may effectively detect the unreliable measured value by using the speed information measured from the INS.

The determination unit 150 of the apparatus 100 for selecting a Doppler measurement value according to an embodiment of the present application may select the Doppler measurement value when the magnitude of the difference between the Doppler measurement value and the Doppler predicted value exceeds a threshold value as the abnormal Doppler measurement value. . That is, when the magnitude of the difference between the Doppler measurement value and the Doppler predicted value exceeds a threshold value for screening the Doppler measurement value, the Doppler measurement value may be determined as including an error and selected as an abnormal Doppler measurement value. Equation 3 may also be understood as detecting the Doppler shift after converting it into meters, and by comparing the value of the actually obtained Doppler measurement with the predicted Doppler measurement (Doppler predicted value), a measurement value including an error can be detected. .

[Equation 3]

는 k 시점에서 j번째 위성에 대한 도플러 측정치,

는 k 시점에서 j번째 위성에 대한 도플러 예측치,

는 GNSS 신호의 파장, c ₁ 은 이상 도플러 측정치를 선별하기 위한 임계값일 수 있다. 도플러 측정치를 선별하기 위한 임계값 c ₁ 은 임의의 상수일 수 있고, 사용자에 의해 설정될 수 있다.In Equation 3 above,

is the Doppler measurement for the j th satellite at time k,

is the Doppler prediction for the j -th satellite at time k,

may be a wavelength of a GNSS signal, and c ₁ may be a threshold value for screening anomaly Doppler measurement. The threshold c ₁ for selecting the Doppler measurement may be any constant and may be set by a user.

As described above, when the magnitude of the difference between the Doppler measured value and the Doppler predicted value exceeds the threshold, the j -th channel is separated or isolated (meaning Isolate channel j in Equation 3), and GNSS raw data including an error It is possible to measure the position and speed of a moving object using raw GNSS data received from other satellite channels except for Isolating the channel j can be equally applied to isolating the channel j as a result of cycle slip and multipath error detection, which will be described later.

The GNSS measurement failure detection apparatus 200 according to an embodiment of the present application includes an INS 110 for measuring speed information in a moving object, a GNSS receiver 120 for receiving GNSS raw data from a plurality of satellites, and an apparatus 100 for selecting Doppler measurement values. ), a cycle slip detector 160 that detects cycle slip by considering the difference between the carrier phase measurement increment measured from the GNSS raw data and the Doppler measurement value excluding the abnormal Doppler measurement, and the pseudorange measurement increment and anomaly Doppler measured from the GNSS raw data It may include a multipath error detection unit 170 that detects a multipath error in consideration of a difference between the Doppler measurement values excluding the measurement values.

The INS 110 may measure speed information from a moving object (or vehicle). For example, based on the inertial sensor provided in the moving object, the speed information may be measured by receiving the gyro measurement value or the accelerometer measurement value of the inertial sensor, and the speed information may be transmitted to the receiver 130 of the Doppler measurement value sorting device 100 . can transmit

The GNSS receiver 120 may receive GNSS raw data from a plurality of satellites 400 . The GNSS receiver 120 may transmit the received GNSS raw data to the receiver 130 of the apparatus 100 for selecting a Doppler measurement value.

The GNSS receiver 120 may receive a GPS signal from a GPS satellite. The GPS signal consists of a carrier frequency, a Pseudo Random Noise (PRN) code modulated by the BPSK (Binary Phase Shift Keying) method, and a navigation message modulated by the BPSK method. The defined L frequency band (Frequency band) of 1 GHz to 2 GHz is used. The GPS satellite network uses a Code Division Multiple Access (CDMA) scheme.

Also, the GNSS receiver 120 may receive a GLONASS signal from a GLONASS satellite. The GLONASS satellite network uses a frequency division multiple access (FDMA) scheme.

Also, the GNSS receiver 120 may receive a BeiDou signal from a BeiDou satellite. BeiDou satellites, like GPS satellites, can estimate the user's location, speed, and time information. The BeiDou signal consists of a carrier frequency, a code, and a navigation message, and uses the L frequency band of 1 GHz to 2 GHz like GPS. Carrier frequencies are 1561.098 MHz, 1589.742 MHz, 1207.140 MHz, and 1268.520 MHz, respectively, using specific frequencies B1, B1-2, B2, and B3 among the L bands. The B1, B1-2, B2, and B3 signals are composed of the sum of the I-channel signal and the Q-channel signal that are out of phase by 90°, and the code and the navigation message are modulated by QPSK (Quadrature Phase Shift Keying). The BeiDou satellite network uses a Code Division Multiple Access (CDMA) scheme.

For example, the GNSS receiver 120 may receive GNSS raw data from each of a GPS satellite, a GLONASS satellite, and a BeiDou satellite among a GPS satellite, a GLONASS satellite, and a BeiDou satellite at a k-th (eg, first) time point. The GNSS receiver 120 may receive a GPS signal from a GPS satellite and a BeiDou signal from a BeiDou satellite.

The GNSS measurement failure detection apparatus 200 may include a Doppler measurement value screening apparatus including a receiver 130 , a calculator 140 , and a determiner 150 . The Doppler measurement value screening apparatus 100 may include a receiver 130 , a calculator 140 , and a determiner 150 , and as described above, the calculator 140 receives the data received from the receiver 130 . A Doppler measurement value and a Doppler predicted value may be calculated using the GNSS raw data and velocity information, and the determination unit 150 may select an abnormal Doppler measurement value including an error in consideration of the difference between the Doppler predicted value and the Doppler measurement value. By selecting and isolating the satellite that transmitted the GNSS raw data corresponding to the selected anomaly Doppler measurement or the GNSS raw data used to calculate the abnormal Doppler measurement, failure of GNSS raw data (or GNSS measurement) can be detected, monitored, and monitored. have.

The cycle slip detection unit 160 may detect the cycle slip based on the increment of the carrier phase measurement value measured from the GNSS raw data, the Doppler measurement value, and the abnormal Doppler measurement value. A multipath error may be detected based on the distance measurement increment and the Doppler measurement and the abnormal Doppler measurement. Also, the cycle slip detection unit 160 may block (isolate) a satellite or a satellite channel in which cycle slip is detected based on the cycle slip detection result, and the multipath error detection unit 170 may detect the multipath error based on the result of the detection of the multipath error. Thus, it is possible to block (isolate) the satellite or satellite channel in which the multipath error is detected. Blocking a satellite or satellite channel in which cycle slip or multipath error is detected may be understood as the same as blocking a satellite or satellite channel according to the above-described selected anomaly Doppler measurement.

As will be described later, when the magnitude of the difference between the increment of the carrier phase measurement value and the Doppler measurement value excluding the abnormal Doppler measurement value exceeds a preset threshold value c2, the GNSS raw data (or satellite) , satellite channels) can be selected and separated into abnormal data including errors. As described above, the selection (separation) of abnormal data means measuring the position, speed, etc. of a moving object using the GNSS raw data received from the remaining satellites except for the satellite channel that transmitted the GNSS raw data used for calculating the abnormal data. It can mean to (calculate). That is, the cycle slip detection unit 160 may detect the cycle slip by using the magnitude of the difference between the increment of the carrier phase measurement value and the Doppler measurement value.

The increment of the carrier phase measurement value for detecting the cycle slip in the cycle slip detection unit 160 may be measured from GNSS raw data, in which case the GNSS raw data is blocked (isolated) according to the selected abnormal Doppler measurement, except for satellites or satellite channels. It may be GNSS raw data received from the remaining satellites. That is, the cycle slip detection unit 160 increments the carrier phase measurement value measured from GNSS raw data received from satellites other than the satellite or satellite channels that are blocked (isolated) according to the selected abnormal Doppler measurement value, and the Doppler measurement value excluding the abnormal Doppler measurement value. Cycle slip can be detected by considering the difference in .

Since the cycle slip detection unit 160 uses the magnitude of the difference between the increment of the carrier phase measurement value and the Doppler measurement value to detect the cycle slip, the Doppler measurement value may be a criterion for determining whether cycle slip occurs. That is, the cycle slip detection unit 160 may detect the cycle slip based not only on the carrier phase measurement value increment and the Doppler measurement value, but also on the basis of the abnormal Doppler measurement value (using the Doppler measurement value excluding the abnormal Doppler measurement value among the Doppler measurements).

That is, the GNSS raw data (satellite channel) of the satellite corresponding to the abnormal Doppler measurement value selected from among the Doppler measurement values may be isolated and excluded. If there is an abnormality in the Doppler measurement (when the Doppler measurement is selected as an abnormal Doppler measurement), even though the carrier phase measurement has an error due to cycle slip, it can be selected as normal data due to the error in the Doppler measurement, and the cycle By calculating the position and speed of the moving object using the carrier phase measurement value including the error due to slip, errors in the position and speed of the moving object may occur. That is, the cycle slip detection unit 160 performs the Doppler measurements from the satellites from which the abnormal Doppler measurements are selected from among the plurality of satellites 400 or from the satellites other than the satellite channels (ie, among the Doppler measurements measured from the plurality of satellites 400 ). By detecting the cycle slip using the rest of the Doppler measurement values excluding the abnormal Doppler measurement value), it is possible to prevent the occurrence of errors in the position and speed of the moving object by determining that the carrier phase measurement containing the error is normal due to the error in the Doppler measurement value. have.

Since the multipath error detection unit 170 uses the magnitude of the difference between the increment of the pseudorange measurement value and the Doppler measurement value to detect the multipath error, the Doppler measurement value can be a criterion for determining whether a multipath error occurs. The multipath error detection unit 170 may detect a multipath error based on the abnormal Doppler measurements (using Doppler measurements excluding the abnormal Doppler measurements from among the Doppler measurements) as well as the pseudorange measurement increments and Doppler measurements.

The pseudorange measurement value increment for detecting the multipath error in the multipath error detection unit 170 may be measured from GNSS raw data, in which case the GNSS raw data is a satellite or satellite channel blocked (isolated) according to the selected abnormal Doppler measurement value. It may be GNSS raw data received from the remaining satellites except for . That is, the multipath error detection unit 170 increments the pseudorange measurement value measured from the GNSS raw data received from the remaining satellites except for the satellite or satellite channel that is blocked (isolated) according to the selected abnormal Doppler measurement value and Doppler excluding the abnormal Doppler measurement value. Multipath error can be detected by considering the difference in measurement values.

That is, the GNSS raw data (satellite channel) of the satellite corresponding to the abnormal Doppler measurement value selected from among the Doppler measurement values may be isolated and excluded. When there is an abnormality in the Doppler measurement (when the Doppler measurement is selected as an abnormal Doppler measurement), the pseudorange measurement may be selected as normal data due to the error in the Doppler measurement even though an error occurs due to a multipath error. When the position and speed of a moving object are calculated using the pseudorange measurement value including the multipath error, errors in the position and speed of the moving object may occur. That is, the multipath error detection unit 170 performs the Doppler measurement values measured from the satellites other than the satellites or satellite channels from which the abnormal Doppler measurement values are selected among the plurality of satellites 400 (ie, the Doppler measurement values measured from the plurality of satellites 400 ). By detecting the multipath error using the remaining Doppler measurement values)) can do.

Hereinafter, a method for detecting the cycle slip and the multipath error in the cycle slip detection unit 160 and the multipath error detection unit 170, respectively, will be described.

In general, the channel of the GNSS receiver 120 is composed of a delay tracking circuit (DLL, Delay Locked Loop) and a phase tracking circuit (PLL, Phase Locked Loop). The delay tracking circuit uses the code signal to generate a pseudorange measurement, and the phase tracking circuit uses the phase signal to generate a carrier cumulative phase measurement. Various errors such as ionospheric delay, tropospheric delay, clock bias, cycle slip, and multipath error are present in the pseudorange and carrier cumulative phase measured by the single GNSS receiver 120 . Included. According to an embodiment of the present disclosure, the carrier cumulative phase or carrier phase measurement may be generated (calculated) by the GNSS receiver 120 or the cycle slip detection unit 160, and the pseudorange measurement may be generated by the GNSS receiver 120 or multipath error generation It can be created from Hereinafter, it is described that the carrier phase measurement value and the pseudorange measurement value are generated by the GNSS receiver 120 for convenience of description, but the present invention is not limited thereto.

Since GNSS satellites transmit signals at very high altitudes, the strength of the signals received by the receiver is very low. Therefore, in urban areas where there are many obstacles to signal propagation, such as high buildings or overpasses, cycle slip occurs in which the signal is temporarily cut off, or unreliable measurement values are frequently obtained due to multipath error. can see. In order to identify such measurements, a detection technique using a Doppler measurement is widely used, and the Doppler measurement is based on the theory that the increment of the carrier phase measurement and the increment of the pseudorange measurement are equivalent. The Doppler measurement may be obtained by instantaneous motion of the satellite and the receiver obtained by the GNSS receiver 120 .

The cycle slip detection unit 160 and the multipath error detection unit 170 may select the GNSS raw data as normal data or abnormal data by using an FDI technique using Doppler measurements to select such measurement values.

In general, a Doppler measurement is integrated with time to obtain a carrier measurement. Therefore, theoretically, the Doppler measurement value at the present time is the same as the value obtained by subtracting the pseudorange at the current time or the equivalent pseudorange using the carrier phase from the pseudorange at the previous time or the equivalent pseudorange using the carrier phase, respectively. Using this principle, the cycle slip detection unit 160 and the multipath error detection unit 170 may detect and separate the measured value of the channel including the cycle slip or the multipath error.

The cycle slip detection unit 160 determines that the difference between the increments of the Doppler measurement value and the carrier phase measurement value included in the GNSS raw data provided from any one of the one or more satellites is greater than a preset threshold ( c ₂ ). GNSS raw data provided from visible satellites can be classified as abnormal data or data containing errors. In addition, the multipath error detection unit 170 sets a threshold value c ₃ at which the difference between the Doppler measurement value and the pseudo range measurement value increment (increase of the pseudo range) included in the GNSS raw data provided from any one of the one or more satellites is preset. ), the GNSS raw data provided from any one visible satellite may be selected as abnormal data or data containing errors. That is, the Doppler measurement may be a reference for detecting cycle slip and multipath error.

In other words, in order to select whether the measured values measured from the GNSS raw data received from the plurality of satellites 400 are normal or abnormal due to an error included, the Doppler measurement is the increment of the carrier phase measurement (or the carrier cumulative phase) and Based on the theory that the increment of the pseudorange measurement is equivalent to the increment, the magnitude of the difference between the increment of the carrier phase measurement and the Doppler measurement or the magnitude of the difference between the increment of the pseudorange measurement and the Doppler measurement is a preset threshold value ( c ₂ , c ₃ above), respectively. ), the GNSS raw data received from the satellite at that point in time may be classified as abnormal data or data containing errors.

According to an embodiment of the present application, the cycle slip detection unit 160 may detect the cycle slip in consideration of the magnitude of the difference between the carrier phase measurement value increment and the Doppler measurement value excluding the abnormal Doppler measurement value from Equation 4 below. That is, the carrier phase measurement value (carrier phase measurement value increment) and the Doppler measurement value used to detect the cycle slip by the cycle slip detection unit 160 are received from satellites other than the satellite from which the abnormal Doppler measurement value is selected among the plurality of satellites 400. It may be calculated using GNSS raw data.

,

,

,

는 각각 k번째 시점에서 채널 j에 대한 반송파 위상 측정치, 의사거리 측정치, 도플러 측정치, 그리고 GNSS 신호의 파장 이며

와

는 각각 사이클 슬립을 검출하기 위한 임계값, 다중경로오차를 검출하기 위한 임계값으로,

와

는 미리 설정된 임의의 상수이다.In Equations 4 and 5 described below,

,

,

,

are the carrier phase measurements, pseudorange measurements, Doppler measurements, and wavelengths of the GNSS signal for channel j at the kth time, respectively.

Wow

is a threshold value for detecting cycle slip and a threshold value for detecting multipath error, respectively,

Wow

is a preset arbitrary constant.

[Equation 4]

는 (k-1)번째 시점에서 k번째 시점으로의 반송파 위상 측정치 증분이고,

는 k번째 시점에서 도플러 측정치, 즉

의 등가량(Equivalent quantity)이고,

는, j번째 위성에 대한 (k-1)번째 시점에서 k번째 시점으로의 반송파 위상 측정치의 증분과 k번재 시점에서의 도플러 측정치와의 차분값이다.In Equation 4 above

is the increment of the carrier phase measurement from the (k-1)-th time point to the k-th time point,

is the Doppler measurement at the k-th time point, i.e.

is the equivalent quantity of

is the difference between the increment of the carrier phase measurement value from the (k-1)-th time point to the k-th time point for the j -th satellite and the Doppler measurement value at the k-th time point.

의 값이

보다 클 경우 해당 채널의 고장을 검출(또는 사이클 슬립을 검출)하고 분리(격리)할 수 있다. 여기서 c ₂ 는 고장 검출에 적합한 값 또는 사이클 슬립 검출에 적합한 값을 가지도록 미리 설정된 상수일 수 있다.Cycle slip detection unit 160 as in Equation 4,

the value of

If it is larger, it is possible to detect (or detect cycle slip) the failure of the corresponding channel and isolate (isolate). Here, c ₂ may be a constant preset to have a value suitable for fault detection or a value suitable for cycle slip detection.

According to an embodiment of the present application, the multipath error detection unit 170 may detect the multipath error in consideration of the magnitude of the difference between the pseudorange measurement value increment and the Doppler measurement value excluding the abnormal Doppler measurement value from Equation 5 below. That is, the carrier phase measurement value (carrier phase measurement value increment) and the Doppler measurement value used to detect the cycle slip by the multipath error detection unit 170 are received from satellites other than the satellite from which the abnormal Doppler measurement value is selected among the plurality of satellites 400 . It may be calculated using one GNSS raw data.

[Equation 5]

는 (k-1)번째 시점에서 k번째 시점으로의 의사거리 측정치의 증분이고,

는 k번째 시점에서 도플러 측정치, 즉

의 등가량이다.

는 j번째 위성에 대한 (k-1)번째 시점에서 k번째 시점으로의 의사거리 측정치의 증분과 k번째 시점에서 도플러 측정치와의 차분값이다.In Equation 5 above

is the increment of the pseudorange measurement from the (k-1)-th time point to the k-th time point,

is the Doppler measurement at the k-th time point, i.e.

is the equivalent of

is the difference between the increment of the pseudorange measurement from the (k-1)-th time point to the k-th time point for the j -th satellite and the Doppler measurement value at the k-th time point.

의 값이

보다 클 경우 해당 채널의 고장을 검출(또는 다중경로오차를 검출)하고 분리(격리)할 수 있다. 여기서 c ₃ 는 고장 검출에 적합한 값 또는 사이클 슬립 검출에 적합한 값을 가지도록 미리 설정된 상수일 수 있다.Multipath error detection unit 170 as in Equation 5,

the value of

If it is larger than that, it is possible to detect (or detect multipath error) the failure of the corresponding channel and isolate (isolate). Here, c ₃ may be a constant preset to have a value suitable for fault detection or a value suitable for cycle slip detection.

That is, to summarize the above, the cycle slip detection unit 160 uses the magnitude of the difference between the carrier phase measurement value increment and the abnormal Doppler measurement value excluding the abnormal Doppler measurement value at the k-th time point for the j -th satellite among the plurality of satellites 400 . to detect the cycle slip to isolate the corresponding satellite or the corresponding satellite channel, and the multipath error detection unit 170 performs the pseudorange measurement increment and anomaly Doppler at the k-th time point for the j -th satellite among the plurality of satellites 400 . The multipath error may be detected using the magnitude of the difference between the Doppler measurements excluding the measured values to isolate the corresponding satellite or the corresponding satellite channel. That is, by isolating the satellite or satellite channel from which the abnormal Doppler measurement value was previously selected by the determination unit 150 , the cycle slip detection unit 160 and the multipath error detection unit 170 determine the Doppler measurement value except for the abnormal Doppler measurement value including the error. can be used to detect cycle slip and multipath error. Therefore, in the cycle slip detection unit 160 and the multipath error detection unit 170, even though an error occurs in the carrier phase measurement value and the pseudo-range measurement value, it is selected as normal data due to the error of the Doppler measurement value, and is measured using the data. It is possible to prevent errors from occurring in the position and speed of the moving object.

In the above description, the cycle slip detection unit 160 and the multipath error detection unit 170 isolate the abnormal Doppler measurement value selected by the determination unit 150 of the Doppler measurement value selection apparatus 100, and receive it from the isolated satellite based thereon. In a state where one GNSS raw data is isolated, it has been described that cycle slip and multipath error are detected, respectively, but according to the embodiment, the cycle slip detection unit 160 performs a cycle based on the detection result of the multipath error detection unit 170 . The slip may be detected, and conversely, the multipath error detection unit 170 may detect the multipath error based on the detection result of the cycle slip detection unit 160 .

For example, the GNSS measurement failure detection device 200 detects the cycle slip in the cycle slip detection unit 160 based on the screening result of the Doppler measurement value screening device 100 (ie, based on the abnormal Doppler measurement), and then When the multipath error detector 170 detects the multipath error, the multipath error detector 170 may detect the multipath error based on the detection result of the cycle slip detector 160 . That is, since the channel in which the cycle slip is detected by the cycle slip detection unit 160 is determined to contain an error and is isolated, the multipath error detection unit 170 calculates the pseudorange measurement increment and the abnormal Doppler measurement value and the Doppler measurement value in which the cycle slip is detected. The multipath error can be detected using the excluded Doppler measurements.

In other words, when the multipath error detection unit 170 detects the multipath error after the cycle slip detection unit 160 detects the cycle slip, not only the channel in which the abnormal Doppler measurement value is selected but also the channel in which the cycle slip is detected includes an error. GNSS raw data received from the remaining satellites and measured Doppler measurements excluding channels blocked (isolated) according to the selected abnormal Doppler measurement and blocked (isolated) according to cycle slip detection Multipath error can be detected. That is, the pseudorange measurement value increment and Doppler measurement for detecting the multipath error in the multipath error detection unit 170 are blocked based on the intercepted satellite channel (or satellite) and cycle slip detection results according to the selected abnormal Doppler measurement values, respectively. It may be measured from GNSS raw data received from the remaining satellites except for the satellite channels (or satellites) that have been blocked. Multipath error can be detected by considering the difference in .

In addition, when the cycle slip detection unit 160 detects the cycle slip after the multipath error detection unit 170 detects the multipath error, the cycle slip detection unit 160 blocks according to the selected abnormal Doppler measurement value similarly to the above description. Cycle slip can be detected using the GNSS raw data received from the remaining satellites except for the (isolated) channel and the blocked (isolated) channel according to the multipath error detection and the measured Doppler measurements.

That is, the cycle slip detection unit 160 considers the difference between the increment of the carrier phase measurement value and the Doppler measurement value measured from the GNSS raw data received from the remaining satellites except for the isolated satellite among the plurality of satellites 400 to detect the cycle slip. In addition, the multipath error detection unit 170 detects the multipath error in consideration of the difference between the increment of the pseudorange measurement value and the Doppler measurement value measured from the GNSS raw data received from the remaining satellites except for the isolated satellite among the plurality of satellites 400 . can be understood as doing

In summary, the Doppler measurement value screening apparatus 100 according to an embodiment of the present application uses the velocity information received from the INS 110 and the GNSS raw data received from the GNSS receiver 120 , the Doppler measurement value and Doppler A predicted value may be calculated, and an abnormal Doppler predicted value may be detected (or selected) in consideration of a difference between the Doppler measurement value and the Doppler predicted value. By isolating the satellite channel corresponding to the selected anomaly Doppler measurement, the accuracy of the GNSS measurement can be improved.

In addition, the GNSS measurement failure detection apparatus 200 includes the INS 110 , the GNSS receiver 120 , the Doppler measurement value selection apparatus 100 , the cycle slip detection unit 160 , and the multipath error detection unit 170 , and is mounted on a moving object. Measure velocity information from the provided inertial sensor 300 , etc., receive GNSS raw data from a plurality of satellites 400 , and select an abnormal Doppler measurement value using the Doppler measurement value selection device 100 , Doppler measurement value, carrier wave Cycle slip and multipath errors can be detected using phase measurement increments, pseudorange measurements increments, but taking into account anomalous Doppler measurements, i.e., isolating selected anomalous Doppler measurements (or satellite, satellite channel isolation).

2 is a simplified operation flowchart of the GNSS measurement failure detection apparatus 200 according to an embodiment of the present application.

Referring to FIG. 2 , the GNSS measurement failure detection apparatus 200 according to an embodiment of the present application updates the position and speed of a moving object based on the detection results of the cycle slip detection unit 160 and the multipath error detection unit 170 . and an update unit 180 to

Referring to FIG. 2 , the GNSS measurement failure detection apparatus 200 may acquire the initial position and velocity of the moving object calculated using the pseudorange measurement value and the Doppler measurement value during the initialization process. The initialization process may be performed using the pseudorange measurement value and Doppler measurement value measured by the GNSS receiver 120 of the GNSS measurement value failure detection device 200, and a separate initialization unit such as an initializer for calculating the initial position and velocity of the moving object It may be performed by the device.

Referring to FIG. 2 , the GNSS measurement failure detection apparatus 200 may select (detect) an abnormal Doppler measurement value by using the speed information received from the INS 110 during the time transmission process, and the abnormal Doppler measurement value selection result and carrier wave The position and velocity of the moving object can be updated based on the increment of the phase measurement. That is, the GNSS measurement failure detection device 200 selects and isolates the abnormal Doppler measurement value including the error from among the Doppler measurement values based on the speed information about the moving object obtained from the IMU (inertial measurement unit, or inertial sensor 300). Also, by using the remaining Doppler measurement values excluding the abnormal Doppler measurement value among the Doppler measurements, cycle slip may be detected according to the magnitude of the difference from the carrier phase measurement value increment, and the position and speed of the moving object may be updated.

Referring to FIG. 2 , the GNSS measurement value failure detection apparatus 200 may update the position and speed of the moving object by detecting a multipath error in the measurement value update process. For multipath error detection, the rest of the Doppler measurements except for the increment of the pseudorange measurement and the Doppler measurement, or the Doppler measurement of the remaining Doppler measurements except for the Doppler measurement of the satellite (satellite channel) where the abnormal Doppler measurement and the cycle slip were detected among the Doppler measurements. It is possible to update the position and speed of the moving object by detecting the multipath error in consideration of the size of the difference. Additionally, the position and speed of the moving object may be updated by reflecting the altitude information obtained using the barometric altimeter. The position and speed of the moving object may be updated in real time by repeating the time transmission process and the measurement value update process at the next time point after the measurement value update process.

3 to 5 are diagrams illustrating measurement results using the GNSS measurement value failure detection apparatus 200 according to an embodiment of the present application. The following FIGS. 3 to 5 are experimental results performed for about 35 minutes in the downtown area (Tehran-ro, Gangnam-gu, Seoul), and show the analysis results for a total of 135 channels of four satellite groups: GPS, GLONASS, BeiDou, and Galileo.

3 is a diagram illustrating a difference between a Doppler measurement value and a Doppler predicted value according to an embodiment of the present application, and FIG. 4 is a Doppler measurement value and a carrier phase using the conventional method and the GNSS measurement value failure detection apparatus 200 according to an embodiment of the present application. 5 is a diagram showing the difference between the increment of the pseudorange measurement value and the Doppler measurement value using the conventional method and the GNSS measurement failure detection apparatus 200 according to an embodiment of the present application.

4 (a) is a difference between the Doppler measurement value and the carrier phase measurement increment measured according to the conventional method, and FIG. The difference in increments of phase measurements, that is, the difference between the increments of the carrier phase measurements and the remaining Doppler measurements excluding the anomalous Doppler measurements among the Doppler measurements by sorting and isolating the abnormal Doppler measurements from the Doppler measurements.

Fig. 5 (a) is a difference between the increments of the Doppler measurement value and the pseudo-range measurement value measured according to the conventional method, and Fig. 5 (b) is the Doppler measurement value (selected Doppler measurement value) and the pseudo-range measurement value measured according to an embodiment of the present application. The difference in increments of distance measurements, that is, the difference between the increments of the pseudorange measurements and the remaining Doppler measurements excluding the abnormal Doppler measurements from the Doppler measurements by sorting and isolating the abnormal Doppler measurements from the Doppler measurements.

3 to 5 , by using the GNSS measurement failure detection apparatus 200 according to an embodiment of the present application, by detecting and separating (isolating) a channel containing an error in advance, the carrier phase measurement value increment and the pseudorange measurement value increment It can be seen that the difference between the and Doppler measurements is reduced.

That is, the GNSS measurement value failure detection apparatus 200 according to an embodiment of the present application may monitor and detect a failure of the GNSS measurement value by using the speed information received from the INS 110 . The Doppler measurement value screening apparatus 100 may predict a Doppler measurement value by using velocity information of the INS 110 , and detect a Doppler measurement value including an error by using the predicted Doppler prediction value. The Doppler measurement value selection apparatus 100 detects a carrier phase measurement value in which a cycle slip occurred and a pseudorange measurement value including a multipath error by using the selected Doppler measurements (in other words, Doppler measurements other than the abnormal Doppler measurements among the Doppler measurements) can do. In an urban area where unreliable measurements are frequently generated, positioning accuracy may be improved by using the Doppler measurement value screening apparatus 100 and the GNSS measurement failure detection apparatus 200 .

6 to 13 are diagrams illustrating a measurement environment and measurement results using the GNSS measurement value failure detection apparatus 200 according to an embodiment of the present application. The following FIGS. 6 to 13 show results measured using the Doppler measurement value screening apparatus 100 near Teheran-ro, Gangnam-gu, Seoul.

6 is a diagram illustrating a measurement environment using the GNSS measurement value failure detection apparatus 200 according to an embodiment of the present application.

6, the GNSS measurement failure detection apparatus 200 according to an embodiment of the present application is performed near Teheran-ro, Gangnam-gu, Seoul. It can be confirmed that the measurement was performed in an environment where it is difficult to calculate the reference trajectory due to the very poor environment. The following FIGS. 7 to 13 are results measured in the measurement environment shown in FIG. 6 , and a point at which a large abnormality in the Doppler measurement value is detected (in other words, a point where the magnitude of the difference between the Doppler measurement value and the Doppler predicted value exceeds the threshold value) shows the results of the analysis.

7 is a diagram illustrating a difference between a Doppler measurement value and a Doppler predicted value calculated using the GNSS measurement value failure detection apparatus 200 according to an embodiment of the present application in the measurement environment of FIG. 6 .

Referring to FIG. 7 , the determination unit 150 according to an exemplary embodiment of the present disclosure may select an abnormal Doppler measurement value by using a double difference. 7 is a diagram illustrating a difference between a Doppler measured value and a Doppler predicted value expressed using a double difference, and other errors may be removed by using the double difference.

Referring to FIG. 7 , the calculator 140 according to an embodiment of the present application may predict a Doppler measurement value by using velocity information estimated from the GNSS/INS Kalman filter.

It can be seen from FIG. 7 that there are a total of six anomalies with a large difference between the Doppler measured value and the Doppler predicted value. 8 to 13 will describe each abnormal point.

8 to 13 show the measurement result and the position measurement result of the moving object according to the conventional method for the abnormal point 1 to the abnormal point 6 of FIG. 7 in order, and the GNSS measurement value failure detection apparatus 200 according to an embodiment of the present application It is a diagram showing the measurement result used and the position measurement result of the moving object. On the map shown on the left in FIGS. 8 to 13, the position measurement result of the moving object according to the conventional method is displayed by connecting a blue circle, and the moving object according to the GNSS measurement value failure detection apparatus 200 according to an embodiment of the present application. The result of position measurement is indicated by connecting an orange circle.

8 to 13 , by using the GNSS measurement failure detection apparatus 200 according to an embodiment of the present application, it is confirmed that the positioning accuracy is improved by selecting and isolating the Doppler measurement value including the error, that is, the abnormal Doppler measurement value. can

8 to 13 illustrate a point at which an error is included in the Doppler measurement, that is, a point at which an abnormal Doppler measurement is selected. 9, 12, and 13 are for abnormal points 2, 5, and 6, respectively. According to the magnitude of the difference between the carrier phase measurement increment and the Doppler measurement, cycle slip or multipath error is detected and detected as abnormal data. In other words, both the conventional method and the GNSS measurement failure detection apparatus 200 according to an embodiment of the present application select the GNSS raw data of the corresponding satellite channels (BeiDou #13, BeiDou #13, and GPS #2, respectively) as abnormal data. And in isolation, accuracy is maintained, but in the case of FIGS. 8, 10, and 11 for abnormal points 1, 3, and 4 (BeiDou #12, BeiDou #13, GLONASS #6, respectively), in one embodiment of the present application According to the GNSS measurement failure detection device 200 according to the difference between the Doppler measurement value and the Doppler predicted value, the abnormal Doppler measurement value may be selected and the corresponding channel (or satellite, satellite channel) may be selected and isolated, but according to the conventional method, the carrier phase It can be confirmed that the error increases because cycle slip or multipath error is not detected by the magnitude of the difference between the measurement increment and the Doppler measurement or the difference between the pseudorange measurement increment and the Doppler measurement.

That is, it may be understood that an error is included in the Doppler measurement value at the abnormal points 1, 3, and 4 of FIGS. 8, 10, and 11 . According to the conventional method, since the error is included in the Doppler measurement, which is the reference in the cycle slip detection or the multipath error detection, the carrier phase measurement value or the pseudorange measurement value containing the error (that is, an abnormality) is detected. It can be seen that the error increases in measuring the position of the moving object, etc. On the other hand, the GNSS measurement failure detection apparatus 200 according to an embodiment of the present application selects an abnormality (or a Doppler measurement value including an error) of the Doppler measurement value using the Doppler measurement value selection apparatus 100, thereby improving the reliability of the GNSS measurement value. can be raised

The difference between the GNSS measurement value failure detection apparatus 200 and the conventional method according to an embodiment of the present application will be described with reference to FIG. 8 among FIGS. 8, 10 and 11 . 8 (abnormal point 1), in the case of the GNSS measurement failure detection apparatus 200 according to an embodiment of the present application, the Doppler error (difference between the Doppler measurement value and the Doppler predicted value) is -3.98 m, which is selected as an abnormal Doppler measurement value and isolated This can prevent errors from occurring. On the other hand, according to the conventional method, the difference between the carrier phase and Doppler (the difference between the increment of the carrier phase measurement and the Doppler measurement) is -0.18 m, and the difference between the pseudorange and the Doppler (the difference between the increment of the pseudorange measurement and the Doppler measurement) is - At 0.11 m, cycle slip and multipath errors were not detected, confirming that errors occurred.

As described above, according to the conventional method, the failure to detect cycle slip or multipath error using the carrier phase measurement value or the pseudorange measurement value at the abnormal points 1, 3, and 4 is the difference between the cycle slip detection and the multipath error detection. This may be because the reference Doppler measurement contains an error. In the case of the conventional method, when an error is included in the Doppler measurement value, an error occurs in measuring the position of the moving object, etc., whereas in the case of the GNSS measurement value failure detection apparatus 200 according to an embodiment of the present application, FIG. 8 , 10 and 11 , it can be confirmed that the position, positioning, etc. of the moving object is accurately measured by selecting that an error is included in the Doppler measurement value, that is, selecting an abnormal Doppler measurement value.

14 is a schematic configuration diagram of the Doppler measurement value selection apparatus 100 and the GNSS measurement value failure detection apparatus 200 according to an embodiment of the present application.

14A is a schematic configuration diagram of an apparatus 100 for selecting a Doppler measurement value. Referring to FIG. 14A , the apparatus 100 for selecting a Doppler measurement value according to an embodiment of the present application includes a receiver 130 and a calculation It may include a unit 140 and a determination unit 150 .

The receiver 130 may receive speed information from the INS 110 , and may receive GNSS raw data from the GNSS receiver 120 .

The calculator 140 may calculate a Doppler measurement value based on the GNSS raw data, and may calculate a Doppler predicted value based on the velocity information and the GNSS raw data. The Doppler measurement value is due to the Doppler effect generated by the relative movement and motion of the moving object and the satellite, and may be measured using frequencies transmitted and received for the j -th satellite among the plurality of satellites 400 , respectively. The Doppler predicted value may be calculated based on the speed information of the moving object and GNSS raw data by modeling the frequency shift due to the Doppler effect using the speed of the moving object, the speed of the satellite, and the line-of-sight vector for the satellite.

The determination unit 150 may select an abnormal Doppler measurement value including an error in consideration of a difference between the Doppler measurement value and the Doppler predicted value. The determination unit 150 may select the Doppler measurement value as the abnormal Doppler measurement value when the magnitude of the difference between the Doppler measurement value and the Doppler predicted value exceeds a threshold value.

The Doppler measurement is a standard for cyclic slip detection or multipath error detection, which is commonly used to obtain the position of a moving object. . The determination unit 150 of the Doppler measurement value screening apparatus 100 of the present application may determine whether an error is included in the Doppler measurement value in consideration of the magnitude of the difference between the Doppler measurement value and the Doppler predicted value, and an abnormal Doppler measurement value among the Doppler measurement values By selecting and isolating , it is possible to increase the accuracy of location acquisition or positioning measurement.

14 (b) is a schematic configuration diagram of a GNSS measurement failure detection apparatus 200 according to an embodiment of the present application. Referring to FIG. 14 (b), a GNSS measurement failure detection apparatus 200 according to an embodiment of the present application ) may include the INS 110 , the GNSS receiver 120 , the Doppler measurement value selection device 100 , the cycle slip detector 160 , the multipath error detector 170 , and the updater 180 .

The INS 110 may transmit speed information of the moving object to the receiver 130 , and the speed information may be based on the inertial sensor 300 provided in the moving object. For example, the inertial sensor 300 may measure a speed, a rotational speed, a direction, a slope, an acceleration, etc. for each of the x, y, and z axes. In another embodiment, speed information may be measured by receiving a gyro measurement or an accelerometer measurement from the inertial sensor 300 .

The GNSS receiver 120 may receive GNSS raw data from the plurality of satellites 400 and transmit it to the receiver 130 . The plurality of satellites 400 may include a GPS satellite, a GLONASS satellite, a BeiDou satellite, a Galileo satellite, and the like. The GNSS receiver 120 may generate (calculate, calculate) a Doppler measurement value, a carrier phase measurement value, a pseudorange measurement value, etc. from GNSS raw data according to an aspect of the embodiment, and a cycle slip detection unit 160, a multipath error detection unit to be described later Receiving GNSS raw data at 170 may be to generate carrier phase measurements and pseudorange measurements, respectively. As described above, the Doppler measurement value screening apparatus 100 may include the receiving unit 130 , the calculating unit 140 , and the determining unit 150 , and the speed information from the INS 110 and the GNSS raw material from the GNSS receiver 120 . By receiving the data, a Doppler measurement value and a Doppler predicted value may be calculated, and an abnormal Doppler measurement value may be selected in consideration of a difference between the calculated Doppler measurement value and the Doppler predicted value. In addition, it is possible to isolate the selected anomalous Doppler measurement (ie, isolate a satellite or satellite channel corresponding to the anomalous Doppler measurement).

The cycle slip detection unit 160 may detect the cycle slip in consideration of the difference between the increment of the carrier phase measurement value measured from the GNSS raw data and the Doppler measurement value excluding the abnormal Doppler measurement value, and the multipath error detection unit 170 is from the GNSS raw data. The multipath error can be detected by considering the difference between the measured pseudorange measurement increment and the Doppler measurement value excluding the abnormal Doppler measurement value. Also, the cycle slip detection unit 160 and the multipath error detection unit 170 may block (isolate) the corresponding satellite (or satellite channel) based on the cycle slip and multipath error detection results, respectively.

That is, the cycle slip detection unit 160 and the multipath error detection unit 170 respectively detect the cycle slip and the multipath error based on the result of isolating the abnormal Doppler measurement value selected as including the error by the determination unit 150 , respectively. can do. The cycle slip detection unit 160 and the multipath error detection unit 170 are measured using GNSS data received from a satellite or a satellite channel other than a satellite or satellite channel corresponding to an abnormal Doppler measurement value selected from among the plurality of satellites 400 . By detecting cycle slip or multipath error using the carrier phase measurement and pseudorange measurement, and Doppler measurements not identified as abnormal Doppler measurements, the accuracy of the cycle slip or multipath error detection is improved, and the position, speed, etc. of the moving object are detected. It is possible to reduce the error in measurement and increase the accuracy.

The update unit 180 may update the position and speed of the moving object based on the detection results of the cycle slip detection unit 160 and the multipath error detection unit 170 . When the cycle slip detection unit 160 or the multipath error detection unit 170 detects a cycle slip or a multipath error, the corresponding satellite or satellite channel may be blocked. The update unit 180 may update the position, speed, etc. of the moving object by using the carrier phase measurement value and the pseudo-range measurement value in which cycle slip or multipath error is not detected. In addition, the update unit 180 is based on the detection results of the cycle slip detection unit 160 and the multi-path error detection unit 170 to update the position and speed of the moving object, and the cycle slip detection unit 160 and the multi-path error detection unit ( 170) detects cycle slip and multipath error, respectively, based on the selection result of the abnormal Doppler measurement value of the determination unit 150 of the apparatus 100 for selecting the Doppler measurement value. It can be understood as the same as updating the position and speed of the moving object based on the selection result of the abnormal Doppler measurement value and the detection results of the cycle slip detection unit 160 and the multipath error detection unit 170 .

Hereinafter, the Doppler measurement value selection method and the GNSS measurement failure detection method illustrated in FIG. 15 may be performed by the Doppler measurement value selection apparatus 100 and the GNSS measurement failure detection apparatus 200 described above. Therefore, even if omitted below, the descriptions of the Doppler measurement value selection apparatus 100 and the GNSS measurement value failure detection apparatus 200 may be equally applied to the description of the Doppler measurement value selection method and the GNSS measurement failure detection method.

In other words, the Doppler measurement value selection method may be performed using the Doppler measurement value selection apparatus 100 and the GNSS measurement failure detection method may be performed by the GNSS measurement value failure detection apparatus 200 , so the Doppler measurement value selection apparatus 100 ) and the description of the GNSS measurement failure detection apparatus 200 may be applied to a Doppler measurement value selection method and a GNSS measurement value failure detection method, respectively.

15 is an operation flowchart of a method for selecting a Doppler measurement value according to an embodiment of the present application.

Referring to FIG. 15 , in step S100 , the receiver 130 may receive GNSS raw data received from the plurality of satellites 400 from the GNSS receiver 120 , and may receive speed information from the INS 110 .

Next, in step S110 , the calculator 140 may calculate a Doppler measurement value based on the GNSS raw data, and may calculate a Doppler predicted value based on the velocity information and the GNSS raw data.

Next, in step S120 , it may be determined whether a difference between the measured Doppler value and the Doppler predicted value is equal to or greater than a threshold value. The determination unit 150 may select an abnormal Doppler measurement value in consideration of the magnitude of the difference between the Doppler measurement value and the Doppler predicted value (ie, by determining whether the magnitude of the difference between the Doppler measurement value and the Doppler predicted value is equal to or greater than a threshold value). When the magnitude of the difference between the Doppler measurement value and the Doppler predicted value exceeds a preset threshold value, the Doppler measurement value may be classified as an abnormal Doppler measurement value and isolated in step S130. Isolating the selected anomalous Doppler measurement means isolating the GNSS raw data used to calculate the anomaly Doppler measurement and then excluding it from cycle slip detection, multipath error detection, and position update of a moving object, or satellites corresponding to the abnormal Doppler measurement or It may mean excluding the GNSS raw data received from the satellite channel.

16 is an operation flowchart of a GNSS measurement failure detection method according to an embodiment of the present application.

Referring to FIG. 16 , in step S200 , the INS 110 may measure speed information from a moving object. The speed information may be obtained based on the inertial sensor 300 provided in the moving object.

Next, in step S210 , the GNSS receiver 120 may receive GNSS raw data from the plurality of satellites 400 .

Next, in step S220, the abnormal Doppler measurement may be selected using the Doppler measurement value screening method, and the satellite (satellite channel or GNSS raw data received from the satellite) may be blocked (isolated) according to the selected abnormal Doppler measurement value. have.

Next, in step S230 , the cycle slip detection unit 160 may detect the cycle slip in consideration of the difference between the increment of the carrier phase measurement value measured from the GNSS raw data and the Doppler measurement value excluding the abnormal Doppler measurement value. For example, when the magnitude of the difference between the carrier phase measurement increment and the Doppler measurement exceeds a threshold, cycle slip may be detected.

In this case, as described above, the carrier phase measurement increment may be measured from GNSS raw data received from satellites excluding satellites (or satellite channels) blocked according to the selected abnormal Doppler measurement values. In addition, in step S230, the corresponding satellite (or satellite channel) may be blocked (isolated) according to the cycle sleep detection result.

Next, in step S240 , the multipath error detection unit 170 may detect the multipath error in consideration of the difference between the increment of the pseudorange measurement value measured from the GNSS raw data and the Doppler measurement value excluding the abnormal Doppler measurement value. For example, when the magnitude of the difference between the pseudorange measurement increment and the Doppler measurement exceeds a threshold, cycle slip may be detected.

In this case, the pseudorange measurement value increment may be measured from GNSS raw data received from satellites excluding satellites (or satellite channels) blocked according to the selected abnormal Doppler measurement values as described above. In addition, in step S240 , the corresponding satellite (or satellite channel) may be blocked (isolated) according to the multipath error detection result.

Also, in step S240, the pseudorange measurement value increment is received from the remaining satellites except for the satellite (or satellite channel) blocked (or isolated) according to the selected anomaly Doppler measurement value and the blocked satellite (or satellite channel) according to the cycle slip detection result. It may be measured from one GNSS raw data, and the Doppler measurement may be measured from GNSS raw data received from other satellites excluding satellites (or satellite channels) that are blocked according to the abnormal Doppler measurement and cycle slip detection results.

According to an embodiment, the order of steps S230 and S240 may be different depending on the aspect, and the GNSS measurement failure detection method of the present application may be performed in the order of steps S240 and S230 after step S220. At this time, in step S230, the carrier phase measurement value increment is received from the remaining satellites except for the satellite (or satellite channel) blocked (or satellite channel) according to the selected anomaly Doppler measurement value and the blocked satellite (or satellite channel) according to the multipath error detection result. It may be measured from one GNSS raw data, and the Doppler measurement may be measured from GNSS raw data received from other satellites except for a satellite (or satellite channel) that is blocked according to an abnormal Doppler measurement and a multipath error detection result.

In the GNSS measurement failure detection method according to an embodiment of the present application, according to the Doppler measurement value selection method in step S220, the abnormal Doppler measurement value determined to contain an error may be selected in consideration of the magnitude of the difference between the Doppler measurement value and the Doppler predicted value. and a corresponding satellite or satellite channel may be blocked according to the selected abnormal Doppler measurement value. Therefore, in steps S230 and S240, by selecting and isolating an anomaly Doppler measurement containing an error from among the Doppler measurement values that are the standards for cycle slip detection and multipath error detection, GNSS measurements (eg, carrier phase measurements or pseudorange measurements, etc.) ) failure can be checked or monitored, and the reliability of cycle slip detection or multipath error detection can be improved.

In steps S220, S230, and S240, the threshold values for detecting abnormal Doppler measurement value selection, cycle slip detection, and multipath error are preset to be suitable for abnormal Doppler measurement value selection, cycle slip detection, and multipath error detection, respectively, and have different values. can be set to

The Doppler measurement value selection method or the GNSS measurement value failure detection method according to an embodiment of the present application may be implemented in the form of a program instruction that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, etc. alone or in combination. The program instructions recorded on the medium may be specially designed and configured for the present invention, or may be known and available to those skilled in the art of computer software. Examples of the computer-readable recording medium include magnetic media such as hard disks, floppy disks and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic such as floppy disks. - includes magneto-optical media, and hardware devices specially configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine language codes such as those generated by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to carry out the operations of the present invention, and vice versa.

In addition, the above-described Doppler measurement value selection method or GNSS measurement value failure detection method may be implemented in the form of a computer program or application executed by a computer stored in a recording medium.

The foregoing description of the present application is for illustration, and those of ordinary skill in the art to which the present application pertains will understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present application. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. For example, each component described as a single type may be implemented in a distributed manner, and likewise components described as distributed may also be implemented in a combined form.

The scope of the present application is indicated by the following claims rather than the above detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present application.

10: Doppler measurement screening system
100: Doppler measurement value sorting device
110: INS
120: GNSS receiver
130: receiver
140: output unit
150: judgment unit
160: cycle slip detection unit
170: multipath error detection unit
180: update part
200: GNSS measurement failure detection device
300: inertial sensor
400: multiple satellites

Claims (14)

a receiving unit that receives speed information measured and transmitted by the INS from a mobile device, and receives GNSS raw data received by the GNSS receiver from a plurality of satellites;
a calculation unit calculating a Doppler measurement value based on the GNSS raw data and calculating a Doppler predicted value based on the velocity information and the GNSS raw data; and
a determination unit that selects an abnormal Doppler measurement value including an error in consideration of a difference between the Doppler measurement value and the Doppler predicted value;
A device for screening Doppler measurements comprising a. According to claim 1,
The speed information is obtained based on an inertial sensor provided in the moving object, the Doppler measurement value selection device. According to claim 1,
in the calculator
The Doppler measurement is calculated by Equation 1 below,
[Equation 1]

In Equation 1 above

is the Doppler measurement for the j -th satellite,

Wow

are the received and transmitted frequencies for the j -th satellite, respectively,
The Doppler predicted value is calculated by Equation 2 below,
[Equation 2]

In Equation 2 above

is the Doppler predicted value,

is the frequency transmitted for the j -th satellite,

is the speed of light,

is the line-of-sight vector for the j -th satellite,

is the velocity of the j-th satellite defined in the ECEF (Earth-Centered Earth-Fixed) coordinate system,

is the velocity of the moving object defined in the ECEF coordinate system, the Doppler measurement value screening device. According to claim 1,
The judging unit,
and classifying the Doppler measurement value as the abnormal Doppler measurement value when a difference between the Doppler measurement value and the Doppler predicted value exceeds a threshold value. INS for measuring speed information in moving objects;
a GNSS receiver for receiving GNSS raw data from a plurality of satellites;
A device for sorting Doppler measurements according to claim 1 ;
a cycle slip detection unit configured to detect cycle slip in consideration of a difference between the increment of the carrier phase measurement value measured from the GNSS raw data and the Doppler measurement value excluding the abnormal Doppler measurement value; and
a multipath error detector configured to detect a multipath error in consideration of the difference between the increment of the pseudorange measurement value measured from the GNSS raw data and the Doppler measurement value excluding the abnormal Doppler measurement value;
Including, GNSS measurement failure detection device. 6. The method of claim 5,
The speed information is obtained based on the inertial sensor provided in the moving object, GNSS measurement failure detection device. 6. The method of claim 5,
The calculation unit,
The Doppler measurement value is calculated by the following Equation 3,
[Equation 3]

In Equation 3 above

is the Doppler measurement for the j -th satellite,

Wow

are the received and transmitted frequencies for the j -th satellite, respectively,
The Doppler predicted value is calculated by the following Equation 4,
[Equation 4]

In Equation 4 above

is the Doppler predicted value,

is the frequency transmitted for the j -th satellite,

is the speed of light,

is the line-of-sight vector for the j -th satellite,

is the velocity of the j-th satellite defined in the ECEF (Earth-Centered Earth-Fixed) coordinate system,

is the speed of the moving object defined in the ECEF coordinate system, GNSS measurement failure detection device. 6. The method of claim 5,
The judging unit,
When the magnitude of the difference between the Doppler measurement value and the Doppler predicted value exceeds a threshold value, the Doppler measurement value is selected as the abnormal Doppler measurement value. 6. The method of claim 5,
and an update unit for updating the position and speed of the moving object based on the detection results of the cycle slip detection unit and the multipath error detection unit. (a) receiving speed information measured and transmitted by the INS from a mobile body, and receiving, by a GNSS receiver, raw GNSS data received from a plurality of satellites;
(b) calculating a Doppler measurement value based on the GNSS raw data, and calculating a Doppler prediction value based on the velocity information and the GNSS raw data; and
(c) selecting an abnormal Doppler measurement value including an error in consideration of the difference between the Doppler measurement value and the Doppler prediction value;
A method for screening Doppler measurements comprising: 11. The method of claim 10,
In step (b),
The Doppler measurement is calculated by Equation 5 below,
[Equation 5]

In Equation 5 above

is the Doppler measurement for the j -th satellite,

Wow

are the received and transmitted frequencies for the j -th satellite, respectively,
The Doppler predicted value is calculated by Equation 6 below,
[Equation 6]

In Equation 6 above

is the Doppler predicted value,

is the frequency transmitted for the j -th satellite,

is the speed of light,

is the line-of-sight vector for the j -th satellite,

is the velocity of the j-th satellite defined in the ECEF (Earth-Centered Earth-Fixed) coordinate system,

is the velocity of the moving object defined in the ECEF coordinate system, the Doppler measurement method screening method. 11. The method of claim 10,
Step (c) is,
and selecting the Doppler measurement value as the abnormal Doppler measurement value when a magnitude of a difference between the Doppler measurement value and the Doppler predicted value exceeds a threshold value. (d) measuring, by the INS, speed information from the moving object;
(e) receiving, by a GNSS receiver, GNSS raw data from a plurality of satellites;
(f) selecting the abnormal Doppler measurement according to the Doppler measurement selection method according to claim 10;
(g) detecting a cycle slip in consideration of a difference between the carrier phase measurement increment measured from the GNSS raw data and the Doppler measurement excluding the abnormal Doppler measurement; and
(h) detecting a multipath error in consideration of the difference between the increment of the pseudorange measurement value measured from the GNSS raw data and the Doppler measurement value excluding the abnormal Doppler measurement value;
GNSS measurement failure detection method including 14. The method of claim 13,
Step (b) is,
The Doppler measurement value is calculated by the following Equation 7,
[Equation 7]

In Equation 7 above

is the Doppler measurement for the j -th satellite,

Wow

are the received and transmitted frequencies for the j -th satellite, respectively,
The Doppler predicted value is calculated by the following Equation 8,
[Equation 8]

In Equation 8 above

is the Doppler predicted value,

is the frequency transmitted for the j -th satellite,

is the speed of light,

is the line-of-sight vector for the j -th satellite,

is the velocity of the j-th satellite defined in the ECEF (Earth-Centered Earth-Fixed) coordinate system,

is the velocity of the moving object defined in the ECEF coordinate system, the GNSS measurement failure detection method.

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