KR20210061901A - Apparatus and method to estimate position using multiple receivers - Google Patents

Abstract

The present invention relates to a device and method for estimating a position of a plurality of receivers. The method for estimating a position comprises the steps of: (a) acquiring a preprocessed pseudorange measurement value from reception signals collected by a plurality of receivers provided to correspond to each of a plurality of reception antennas disposed on a moving object; and (b) estimating the positions of each of the plurality of receivers in consideration of predefined constraints in relation to the plurality of receivers and the acquired preprocessed pseudorange measurement values.

Description

Position estimation apparatus and method using a plurality of receivers {APPARATUS AND METHOD TO ESTIMATE POSITION USING MULTIPLE RECEIVERS}

The present application relates to a position estimation apparatus and method using a plurality of receivers. In particular, the present application relates to a location estimation apparatus and method using multiple low-cost small GNSS receivers.

A single, small, low-cost consumer-grade GNSS receiver that is generally used uses only the L1 frequency band and has a position error of several meters. There is a problem that is difficult to use in fields that require a location.

In order to solve this problem, various methods such as differential satellite navigation, real-time kinematic (RTK), network RTK, and Precise Point Positioning (PPP) have been developed in the prior art. However, such conventional methods are difficult to replace commercially inexpensive receivers because they require auxiliary information such as reference station receiver measurement information and precision satellite orbits from outside the receiver, or require expensive GNSS receivers or antennas. There is this.

The technology behind the present application is disclosed in Korean Patent Publication No. 10-2026114.

The present application is to solve the above-described problems of the prior art, and position estimation using a plurality of receivers (especially, a plurality of small low-cost GNSS receivers) capable of improving low positioning accuracy of a single small-sized low-cost (consumer-grade) GNSS receiver. It is intended to provide an apparatus and method.

The present application is to solve the above-described problems of the prior art, without the need to obtain auxiliary information such as reference station receiver measurement information, precision satellite orbits, etc. from outside the receiver, or to provide a commercially inexpensive receiver without the need to have an expensive GNSS receiver or antenna. An object of the present invention is to provide a location estimation apparatus and method using a plurality of small and inexpensive receivers capable of improving positioning accuracy.

However, the technical problem to be achieved by the embodiments of the present application is 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, a method for estimating a location using a plurality of receivers according to an embodiment of the present application includes: (a) in a plurality of receivers provided to correspond to each of a plurality of receiving antennas disposed on a moving object. Obtaining a preprocessed pseudorange measurement value from the collected received signal; And (b) estimating the positions of each of the plurality of receivers in consideration of the pre-processed pseudorange measurement value and the constraints defined in relation to the plurality of receivers.

In addition, in the step (a), each of the plurality of receivers is related to the received signal including a satellite position and a pseudorange measurement value for a visible satellite from a received signal received and collected from a receiving antenna provided to correspond to the receiver. You can calculate the calculated value.

In addition, in step (a), the preprocessed pseudorange measurement value may be obtained by performing preprocessing of removing at least one of a satellite clock error, a tropospheric delay error, and an ionospheric delay error with respect to the calculated value related to the received signal. .

In addition, the pre-defined constraint in step (b) is a first constraint on a distance between the plurality of receivers considering the positions of the plurality of receiving antennas disposed at a preset position with respect to the moving object, and the plurality of A second constraint on the number of receivers of may be included.

In addition, in step (b), based on the pseudorange measurement value and the preprocessed pseudorange measurement value, a linearized indirect measurement value considering the number of visible satellites and the predefined constraints is calculated, and the weighted minimum The positions of each of the plurality of receivers may be estimated from the position estimation error vector of the receiver included in the linearized indirect measurement value estimated using the square method.

Meanwhile, the position estimation apparatus using a plurality of receivers according to an embodiment of the present application obtains a preprocessed pseudorange measurement value from received signals collected from a plurality of receivers provided to correspond to each of a plurality of receiving antennas disposed on a moving object. The acquisition unit; And an estimating unit estimating the positions of each of the plurality of receivers in consideration of the pre-processed pseudorange measurement value obtained and the constraint condition defined in relation to the plurality of receivers.

In addition, each of the plurality of receivers may calculate a calculated value related to the received signal including a position of a satellite and a pseudorange measurement value for a visible satellite from a received signal transmitted from a receiving antenna provided to correspond to the receiver.

In addition, the acquisition unit performs pre-processing of removing at least one of a satellite clock error, a tropospheric delay error, and an ionospheric delay error with respect to the calculated values related to the received signals calculated by the plurality of receivers, and calculates the pre-processed pseudorange measurement value. Can be obtained.

In addition, the predefined constraint is a first constraint on the distance between the plurality of receivers taking into account the positions of the plurality of reception antennas arranged at a preset location with respect to the moving object and the number of the plurality of receivers. It may include a second constraint.

In addition, the estimation unit calculates a linearized indirect measurement value considering the number of visible satellites and the predefined constraints based on the pseudorange measurement value and the preprocessed pseudorange measurement value, and uses a weighted least squares method. Thus, the positions of each of the plurality of receivers may be estimated from the position estimation error vector of the receiver included in the estimated linearized indirect measurement value.

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

According to the above-described problem solving means of the present application, through the provision of a position estimation apparatus using a plurality of receivers (especially, a plurality of small and low cost GNSS receivers), it is possible to improve the low positioning accuracy of a single small, low-cost (consumer-grade) GNSS receiver. I can.

According to the above-described problem solving means of the present application, there is no need to obtain auxiliary information such as reference station receiver measurement information, precision satellite orbit, etc. It is possible to estimate the exact position of each receiver by using predefined constraints for two receivers.

However, the effect obtainable in the present application is not limited to the above-described effects, and other effects may exist.

1 and 2 are diagrams showing a schematic configuration of a position estimation system using a plurality of receivers according to an embodiment of the present application.
3 and 4 are diagrams showing a schematic configuration of a position estimation system using a plurality of receivers according to another embodiment of the present application.
5 is a diagram showing an example of an arrangement configuration of three receivers assumed in a simulation for performance evaluation of a position estimation apparatus using a plurality of receivers according to an embodiment of the present application.
6 to 8 are diagrams showing simulation results according to an experiment of the present application made for performance evaluation of a position estimation apparatus using a plurality of receivers according to an embodiment of the present application.
9 is a view showing another example of a simulation result according to an experiment of the present application made to evaluate the performance of a position estimation apparatus using a plurality of receivers according to an embodiment of the present application.
10 is a flowchart illustrating a method for estimating a location using a plurality of receivers 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 may easily implement the present application. However, the present application may be implemented in various different forms and is not limited to the embodiments described herein. In addition, in the drawings, parts irrelevant to the description are omitted in order to clearly describe the present application, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the present specification, when a part is said to be "connected" with another part, it is not only the case that it is "directly connected", but also "electrically connected" or "indirectly connected" with another element interposed therebetween. "Including the case.

Throughout the present specification, when a member is positioned "on", "upper", "upper", "under", "lower", and "lower" of another member, this means that a member is located on another member. This includes not only the case where they are in contact but also the case where another member exists between the two members.

In the entire specification of the present application, when a certain part "includes" a certain component, it means that other components may be further included rather than excluding other components unless specifically stated to the contrary.

1 and 2 are diagrams showing a schematic configuration of a position estimation system 1000 using a plurality of receivers according to an embodiment of the present application.

Hereinafter, the position estimation system 1000 using a plurality of receivers according to an exemplary embodiment of the present disclosure will be referred to as the present system 1000 for convenience of description.

1 and 2, the system 1000 may include a plurality of reception antennas 10 ′ and a position estimation apparatus 100.

The position estimating apparatus 100 included in the system 1000 may refer to a position estimating apparatus 100 using a plurality of receivers according to an exemplary embodiment of the present disclosure. The position estimation apparatus 100 using a plurality of receivers according to the exemplary embodiment of the present application will be referred to as the apparatus 100 for convenience of description below. The device 100 may be otherwise referred to as a main processing device.

The apparatus 100 (main processing unit) may include, for example, a plurality of receivers 10 provided to correspond to a plurality of receiving antennas 10 ′. In other words, the plurality of receivers 10 may be provided to be included in the device 100 as an example. That is, in the example of the present application, a plurality of receivers 10 may be disposed (arranged) inside the apparatus 100 (main processing unit).

The plurality of receiving antennas 10' (1', 2', …, N') are a plurality of receiving antennas, such as a first receiving antenna 1', a second receiving antenna 2', ... , And an Nth receiving antenna (N'). A plurality of receivers 10 (1, 2, ..., N) are a plurality of receivers, the first receiver 1, the second receiver 2, ... , And an Nth receiver (N).

Herein, the plurality of reception antennas 10 ′ may be referred to differently as a plurality of GNSS reception antennas 10 ′, and the plurality of receivers 10 may be referred to differently as a plurality of GNSS receivers 10. In addition, each of the plurality of receivers 10 considered herein may be a small low-cost GNSS receiver and a commercial low-cost receiver.

The plurality of receivers 10 may mean a receiver provided to correspond to the plurality of reception antennas 10'. That is, each of the plurality of receivers 10 may mean a receiver provided to correspond to each of the plurality of reception antennas 10'. Accordingly, the number of the plurality of receivers 10 and the plurality of receiving antennas 10' considered herein may be set to be the same.

Specifically, the first receiver 1 is a receiver corresponding to the first reception antenna 1', the second receiver 2 is a receiver corresponding to the second reception antenna 2', and the Nth receiver (N ) May mean a receiver corresponding to the N-th reception antenna N'. Here, the receiver corresponding to the reception antenna may mean a receiver interlocked (connected) with the reception antenna. Accordingly, a receiver corresponding to the reception antenna may receive a reception signal received by the reception antenna from the reception antenna.

The plurality of receiving antennas 10 ′ may be disposed at preset positions with respect to the moving object. Here, the moving object may mean, for example, a vehicle (car). However, the present invention is not limited thereto, and any movable object for which a position is to be measured may be applied as a moving object. The moving body may be otherwise referred to as a platform or the like.

The plurality of receiving antennas 10 ′ may be disposed above the vehicle as a moving object, and may be disposed at a preset position above the vehicle.

A plurality of receiving antennas 10' (1', 2', …, N') can receive a signal in the GNSS L1 frequency band as a received signal, and received a received signal (i.e., a signal in the GNSS L1 frequency band). Can be delivered to a plurality of receivers 10.

Each of the plurality of receiving antennas 10 ′ (1 ′, 2 ′, …, N′) may respectively transmit a received signal received by the receiving antenna 10 ′ to a receiver provided corresponding to the receiving antenna. That is, the first receiving antenna 1'can transmit the received signal received by itself to the first receiver 1, which is a receiver interlocked with it, and the second receiving antenna 2'is the received signal received by itself. Can be delivered to the second receiver 1, which is a receiver interlocked with itself. The N-th receiving antenna N'may transmit the received signal received by itself to the N-th receiver N, which is a receiver interlocked with it.

Each of the plurality of receivers 10 (1, 2, …, N) includes a satellite position and a pseudorange measurement value of a visible satellite from a received signal received and collected from a receiving antenna provided to correspond to it. A calculated value related to the received signal can be calculated. That is, each of the plurality of receivers 10 (1, 2, …, N) receives and collects a received signal from a receiving antenna provided to correspond to it, and the location of the satellite relative to the visible satellite from the collected received signal and A calculated value related to the received signal including the measured value of the pseudorange may be calculated.

)와 의사거리 측정값(

)가 포함될 수 있다.For example, the calculated value related to the received signal calculated by the N-th receiver N includes the position of the satellite relative to the visible satellite (

) And pseudorange measurements (

) May be included.

The acquisition unit 20 may acquire a pre-processed pseudorange measurement value from the received signals collected by the plurality of receivers 10 provided to correspond to each of the plurality of receiving antennas 10 ′ disposed on the mobile body.

The acquisition unit 20 determines at least one of a satellite clock bias, a tropospheric delay error, and an ionospheric delay error with respect to the calculated values related to the received signals calculated by the plurality of receivers 10. By performing the pretreatment to remove, the preprocessed pseudorange measurement value can be obtained. The acquisition unit 20 preferably performs preprocessing to remove all of the satellite clock error, the tropospheric delay error, and the ionospheric delay error with respect to the pseudorange measurement values calculated by the plurality of receivers 10, so that the preprocessed pseudorange measurement value Can be obtained as in Equation 5 to be described later.

Thereafter, the estimating unit 30 may estimate the position of each of the plurality of receivers in consideration of the constraints predefined in relation to the plurality of receivers 10 and the preprocessed pseudorange measurement value obtained by the acquisition unit 20. have.

Here, the predefined constraints are a first constraint on the distance between the plurality of receivers 10 in consideration of the positions (geometric arrangement positions) of the plurality of receiving antennas 10 ′ disposed at a preset position with respect to the moving object, and A second constraint on the number of the plurality of receivers 10 may be included.

The estimating unit 30 is based on the pseudorange measurement value in the calculated value related to the received signal and the preprocessed pseudorange measurement value obtained by the acquisition unit 20, based on the number of visible satellites and the linearization of the pre-defined constraints. Indirect measurements can be calculated. Thereafter, the estimating unit 30 may estimate the positions of each of the plurality of receivers 10 from the position estimation error vectors of the receivers included in the linearized indirect measurement values estimated using the weighted least squares method. A more detailed description is as follows.

The received signal collected by each of the plurality of receivers 10 received from the receiving antenna is a signal of the GNSS L1 frequency band, which is the L1 frequency code measurement value, the GNSS measurement value, the pseudorange measurement value (pseudorange measurement value), and the code. It can be expressed differently as a measurement value or the like.

In this way, the received signal collected by each of the plurality of receivers 10 (in other words, the L1 frequency code measurement value collected by each receiver) is basically a GNSS measurement value modeled for the j-th satellite as shown in Equation 1 below. It can be explained assuming. In other words, the received signals collected by each of the plurality of receivers 10 may be expressed as GNSS measurements modeled for the j-th satellite as shown in Equation 1. This Equation 1 may be referred to as a received signal measurement model (code measurement value measurement model).

[Equation 1]

는 j번째 위성에 대한 L1 주파수 의사거리 측정값으로서, 달리 표현해 j번째 위성에 대하여 n번째 수신기가 수신한 수신신호를 의미할 수 있다.

는 j번째 위성과 수신기 간의 기하학적 거리,

는 j번째 위성의 시계오차,

는 n 번째 수신기의 시계오차를 의미할 수 있다.

는 j번째 위성에 대한 대류권지연오차,

는 j번째 위성에 대한 전리층지연오차,

는 j번째 위성에 대한 측정오차를 의미할 수 있다.Here, n may be an index of a receiver, and j may be an index of a satellite. Also,

Is a measurement value of the L1 frequency pseudorange for the j- th satellite, and expressed otherwise, may mean a received signal received by the n- th receiver for the j-th satellite.

Is the geometric distance between the j- th satellite and the receiver,

Is the clock error of the j-th satellite,

May mean a clock error of the n-th receiver.

Is the tropospheric delay error for the j-th satellite,

Is the ionospheric delay error for the j-th satellite,

May mean the measurement error for the j-th satellite.

는 n번째 수신기가 j번째 위성으로부터 수신한 수신신호이자, 이러한 수신신호로부터 수신기가 산출하는 수신신호 산출 값에 포함된 의사거리 측정값을 의미할 수 있다.In other words,

Is a received signal received by the n- th receiver from the j- th satellite, and may mean a pseudorange measurement value included in a received signal calculation value calculated by the receiver from the received signal.

라고 할 때, 위성과 수신기 간의 기하학적 거리인

는 하기 식 2와 같이 표현될 수 있다.Position of receiver (1, 2, …, N)

Is the geometric distance between the satellite and the receiver,

Can be expressed as in Equation 2 below.

[Equation 2]

는 j번째 위성의 x축 좌표,

는 j번째 위성의 y축 좌표,

는 j번째 위성의 z축 좌표를 의미할 수 있다.here,

Is the x-axis coordinate of the j-th satellite,

Is the y-axis coordinate of the j-th satellite,

May mean the z-axis coordinate of the j-th satellite.

According to this, each of the plurality of receivers 10 may receive and collect a received signal from a receiving antenna corresponding to each receiver. At this time, each of the plurality of receivers 10 may calculate a calculated value related to the received signal, including the measured value of the satellite position and the pseudorange of the visible satellite from the collected received signal based on Equation 1 and Equation 2 above. have.

The acquisition unit 20 may obtain a received signal-related calculated value calculated by each of the plurality of receivers 10 from each of the receivers 10. The acquisition unit 20 may obtain a preprocessed pseudorange measurement value as shown in Equation 5 to be described later by performing preprocessing on the calculated values related to the received signal acquired from the plurality of receivers 10. Prior to a detailed description thereof, , When first described with respect to the constraints considered in the present application are as follows.

The predefined constraints considered in the apparatus 100 may include a first constraint and a second constraint.

Here, the first constraint is a constraint on the distance between the plurality of receivers in consideration of the positions (geometric arrangement positions) of the plurality of reception antennas arranged at a predetermined position with respect to the moving object, which may satisfy Equation 3 below. In addition, the second constraint is a constraint on the number of a plurality of receivers, which may satisfy Equation 4 below.

Specifically, in the system 1000, each of the plurality of receiving antennas 10 ′ may be disposed (mounted, installed) at a predetermined (designated) position of the moving object.

In this case, the number of the plurality of reception antennas 10 ′ considered in the system 1000 and the apparatus 100 (or the number of the plurality of receivers) may be set to at least three. That is, in the present system 1000 and the present apparatus 100, at least three or more receiving antennas may be disposed in a preset position in the moving object for position estimation. Accordingly, the apparatus 100 may include three or more receivers disposed at positions corresponding to the preset positions to correspond to each of the three or more reception antennas disposed at a preset position of the moving object. The minimum number of receivers (minimum number of antennas) considered in the system 1000 and the apparatus 100 may be three.

As the plurality of receiving antennas 10' are arranged in a predetermined position on the moving object, the CD, which is the distance between the plurality of receiving antennas 10' disposed on the moving object (i.e., the distance between each receiving antenna), is expressed in Equation 3 below. It can be expressed (defined) as In other words, the first constraint considered in the apparatus 100 may mean a condition that satisfies Equation 3 below.

[Equation 3]

는

번째 수신기와 m 번째 수신기 간의 거리,

는 m 번째 수신기의 위치벡터,

은

번째 수신기의 위치벡터,

는 거리측정오차를 의미할 수 있다.here,

Is

The distance between the mth receiver and the mth receiver,

Is the position vector of the m th receiver,

silver

The position vector of the second receiver,

May mean a distance measurement error.

는 하기 식 4와 같을 수 있다. 달리 말하자면, 본 장치(100)에서 고려되는 제2 제약조건은 하기 식 4를 만족하는 조건을 의미할 수 있다.In addition, when the number of receivers considered in the system 1000 and the apparatus 100 is N, the number of constraints

May be as in Equation 4 below. In other words, the second constraint considered in the device 100 may mean a condition that satisfies Equation 4 below.

[Equation 4]

The estimation unit 30 may estimate the positions of each of the plurality of receivers in consideration of the predefined constraints and the preprocessed pseudorange measurement value obtained by the acquisition unit 20.

Specifically, the acquisition unit 20 may obtain a preprocessed pseudorange measurement value by performing preprocessing on the calculated values related to the received signals obtained from the plurality of receivers 10 as shown in Equation 5 below.

[Equation 5]

In the pseudorange measurement values collected by the GNSS receiver 10 (that is, the received signal that satisfies Equation 1 above), the geometric distance between the satellite and the receiver, a clock bias of the satellite, a clock error of the receiver, and a tropospheric delay. ) Information such as errors and ionospheric delay errors may be included.

Here, the clock error of the satellites can be removed using broadcast orbital power information transmitted from each satellite, the tropospheric delay error can be removed using the tropospheric delay error model, and the ionosphere delay error is broadcast orbital power information and ionosphere. It can be eliminated using the delay error model.

In other words, the acquisition unit 20 with respect to a received signal-related calculation value calculated by the plurality of receivers 10 (this is a pseudorange measurement value expressed as in Equation 1, which may mean a received signal), Using broadcast orbital power information transmitted from each satellite, time error of the satellite is removed, tropospheric delay error is removed using tropospheric delay error model, and ionospheric delay error is calculated using broadcast orbital power information and ionospheric delay error model. Pretreatment to remove can be performed.

In the above-described example of the present application, it is exemplified that broadcast orbital force information, tropospheric delay error model, and ionospheric delay error model are used as an error removal technology for removing satellite clock errors, tropospheric delay errors, and ionospheric delay errors. It is only an example for aiding understanding, and is not limited thereto, and various error removal techniques that are known or developed in the future may be applied herein.

The pseudorange measurement value (that is, the preprocessed pseudorange measurement value) from which the error has been removed may include information on a geometric distance between a satellite and a receiver, a clock error of the receiver, an unmodeled multipath error, and thermal noise.

That is, the acquisition unit 20 may perform preprocessing for removing the satellite clock error, the tropospheric delay error, and the ionospheric delay error with respect to the calculated value related to the received signal (i.e., from the code measurement value measurement model of Equation 1), Through this, it is possible to obtain a preprocessed pseudorange measurement value expressed as in Equation 5 above.

The estimating unit 30 may estimate the positions of each of the plurality of receivers 10 in consideration of the preprocessed pseudorange measurement value obtained by the acquisition unit 20 and the above-described predefined constraint. A more detailed process is as follows.

The estimating unit 30 converts the pseudorange measurement value (that is, the preprocessed pseudorange measurement value of Equation 5) obtained by the acquisition unit 20 into a pseudorange estimate value (ie, the preprocessed pseudorange estimate value) as shown in Equation 6 below. Can be modeled.

[Equation 6]

는 j번째 위성에 대한 의사거리 추정값, 즉 j번째 위성에 대하여 n번째 수신기가 수신한 수신신호를 기반으로 모델링된 전처리된 의사거리 추정값을 의미한다. 또한,

는 j번째 위성의 위치를 의미하고,

는 j번째 위성과 수신기 간의 LOS(Line-Of-Sight) 벡터를 의미하고,

일 수 있다.here,

Denotes a pseudorange estimate for the j- th satellite, that is, a preprocessed pseudo-range estimate modeled based on the received signal received by the n- th receiver for the j-th satellite. Also,

Means the location of the j-th satellite,

Denotes a line-of-sight (LOS) vector between the j-th satellite and the receiver,

Can be

Thereafter, the estimation unit 30 may express a linearized indirect measurement value from the code measurement value of Equation 1 and the preprocessed pseudorange estimation value of Equation 6 as shown in Equation 7 below. In this case, the linearized indirect measurement value represented by Equation 7 may be referred to differently as a first linearized indirect measurement value for convenience of description.

[Equation 7]

는 하기 식 8과 같이 표현될 수 있다.Representing the observation matrix in Equation 7 above

Can be expressed as in Equation 8 below.

[Equation 8]

Based on Equation 7 and Equation 8, the estimating unit 30 expresses the linearized indirect measurements for all visible satellites for each of the plurality of receivers 10 (that is, for each receiver) in a vector form as shown in Equation 9 below. I can. In this case, the linearized indirect measurement value represented by Equation 9 may be referred to differently as a second linearized indirect measurement value for convenience of description.

[Equation 9]

,

일 수 있으며,

는 가시위성의 개수를 의미할 수 있다.here,

,

Can be

May mean the number of visible satellites.

번째 수신기와 m 번째 수신기 간의 제약조건(즉, 각 수신기(혹은 각 안테나) 사이의 거리에 관한 제약조건)에 대한 선형화된 간접측정치를 하기 식 10과 같이 정의할 수 있다. 이때, 식 10으로 표현되는 선형화된 간접측정치는 설명의 편의상 제3 선형화된 간접측정치라 달리 지칭될 수 있다.In addition, the estimation unit 30 is related to the first constraint

A linearized indirect measurement value for a constraint between a th receiver and an m th receiver (that is, a constraint on a distance between each receiver (or each antenna)) may be defined as in Equation 10 below. In this case, the linearized indirect measurement value represented by Equation 10 may be referred to differently as a third linearized indirect measurement value for convenience of description.

[Equation 10]

는

번째 수신기와 m 번째 수신기 간의 거리 추정값,

는 m 번째 수신기의 위치추정벡터,

는

번째 수신기의 위치추정벡터,

는 m 번째 수신기에서

번째 수신기로의 LOS 벡터를 의미할 수 있다. 또한,

,

,

일 수 있다.here,

Is

An estimate of the distance between the mth receiver and the mth receiver,

Is the position estimation vector of the m th receiver,

Is

The position estimation vector of the second receiver,

Is in the m th receiver

It may mean the LOS vector to the th receiver. Also,

,

,

Can be

개의 제약조건에 대한 선형화된 간접측정치를 하기 식 11과 같이 정의할 수 있다. 이때, 식 11로 표현되는 선형화된 간접측정치는 설명의 편의상 제4 선형화된 간접측정치라 달리 지칭될 수 있다.In addition, the estimation unit 30 is related to the second constraint

The linearized indirect measurement value for the constraints of two can be defined as in Equation 11 below. In this case, the linearized indirect measurement value expressed by Equation 11 may be referred to differently as a fourth linearized indirect measurement value for convenience of description.

[Equation 11]

,

일 수 있다.here,

,

Can be

일 때, 수신기 N 개와 제약조건

개를 포함하는 선형화된 간접측정치를 하기 식 12와 같이 벡터형태로 표현할 수 있다. 이때, 식 12로 표현되는 선형화된 간접측정치는 설명의 편의상 제5 선형화된 간접측정치라 달리 지칭될 수 있다.From Equation 9 representing the second linearized indirect measurement value and Equation 11 representing the fourth linearized indirect measurement value, the estimation unit 30 determines the number of visible satellites.

When, N receivers and constraints

Linearized indirect measurements including dogs can be expressed in vector form as shown in Equation 12 below. In this case, the linearized indirect measurement value expressed by Equation 12 may be referred to differently as a fifth linearized indirect measurement value for convenience of description.

[Equation 12]

일 수 있다.here,

Can be

를 하기 식 13과 같이 가중최소자승법을 이용하여 획득(추정)할 수 있다.Estimation unit 30 is the position estimation error vector of the receiver from the linear equation of Equation 12 (that is, the fifth linearized indirect measurement value)

Can be obtained (estimated) using the weighted least squares method as shown in Equation 13 below.

[Equation 13]

,

,

일 수 있다. 또한,

는 n 번째 수신기에 대한 측정오차 공분산 행렬을 의미하고,

는 제약조건 측정오차 공분산 행렬을 의미할 수 있다.here,

,

,

Can be Also,

Is the measurement error covariance matrix for the nth receiver,

May mean the constraint measurement error covariance matrix.

로부터, 복수의 수신기(10) 각각의 위치추정값 및 복수의 수신기(10) 각각의 추정된 수신기 시계오차(수신기의 시계오차)를 하기 식 14와 같이 표현할 수 있다. The estimating unit 30 is the position estimation (state variable estimation) error vector of each receiver obtained (estimated) through Equation 13 above.

From, the position estimation values of each of the plurality of receivers 10 and the estimated receiver clock error (clock error of the receiver) of each of the plurality of receivers 10 can be expressed as in Equation 14 below.

[Equation 14]

가 수렴할 때까지 상술한 과정을 반복함으로써, 복수의 수신기(10) 각각의 위치를 정확하게 추정할 수 있다.Estimation unit 30 is in Equation 14 above

By repeating the above-described process until is converged, the positions of each of the plurality of receivers 10 can be accurately estimated.

The estimating unit 30 may estimate the positions of each of the plurality of receivers 10 in consideration of the pre-defined constraints in relation to the plurality of receivers 10 and the preprocessed pseudorange measurement values obtained by the acquisition unit 20. I can.

The estimation unit 30 includes a linearized indirect measurement value for the first constraint of Equation 3 (a third linearized indirect measurement value), a linearized indirect measurement value for the second constraint of Equation 4 (a second linearized indirect measurement value), And the position of each of the plurality of receivers 10 may be estimated in consideration of the preprocessed pseudorange measurement value of Equation 5 obtained by the acquisition unit 20.

In particular, the estimating unit 30 is based on the pseudorange measurement value of Equation 1 and the preprocessed pseudorange measurement value of Equation 5, based on the number of visible satellites and a linearized indirect measurement value (that is, the first 5 Linearized indirect measurement) can be calculated as Equation 12. Thereafter, the estimating unit 30 is a plurality of receivers 10 from Equation 13, which is a position estimation error vector of the receiver included in the linearized indirect measurement value (the fifth linearized indirect measurement value) of Equation 12 estimated using the plasticity least squares method. ) Each location can be estimated.

At this time, the estimating unit 30 may estimate the position estimation value of each receiver and the receiver clock error (the clock error of the receiver) from Equation 14 as the positions of each of the plurality of receivers 10.

By the above-described process, the estimating unit 30 can estimate the exact position (position solution, position vector) of the receiver using a plurality (especially, three or more) of small and low-cost GNSS receivers 10. The system 1000 and the apparatus 100 can accurately estimate the location of the receiver using a number of low-cost small receivers.

3 and 4 are diagrams showing a schematic configuration of a position estimation system 1000' using a plurality of receivers according to another embodiment of the present application.

Hereinafter, a position estimation system 1000 ′ using a plurality of receivers according to another exemplary embodiment of the present disclosure will be referred to as the system 1000 ′ for convenience of description.

3 and 4, the system 1000 ′ may include a plurality of reception antennas 10 ′, a plurality of receivers 10, and a position estimation apparatus 100 ′.

The position estimating apparatus 100 ′ included in the system 1000 ′ may refer to a position estimating apparatus 100 ′ using a plurality of receivers according to another exemplary embodiment of the present disclosure. The position estimation apparatus 100 ′ using a plurality of receivers according to another exemplary embodiment of the present application will be referred to as the apparatus 100 ′ for convenience of description below. The device 100 ′ may be otherwise referred to as a main processing device.

The plurality of receivers 10 may be provided to correspond to the plurality of receiving antennas 10 ′. In another example of the present application, a plurality of receivers 10 may be disposed (arranged) outside the apparatus 100' (main processing unit).

Accordingly, the system 1000 ′ and the apparatus 100 ′ according to another embodiment of the present application are compared with the system 1000 and the apparatus 100 according to the exemplary embodiment of the present application described above, There is only a difference in that the plurality of receivers 10 are disposed outside the apparatus 100, but may be the same system as the system 1000 and the same apparatus as the apparatus 100 described above.

Therefore, even if the contents are omitted below, the contents described for each of the system 1000 and the apparatus 100 according to the exemplary embodiment of the present application will be described below in the system 1000 ′ and the apparatus 100 ′. The same can be applied to the description. Hereinafter, redundant descriptions will be omitted.

When a plurality of receivers 10 are provided in a structure separated from the device 100' (main processing device) as in another embodiment of the present application (that is, a plurality of receivers are provided outside the device), the present invention A communication unit (not shown) capable of transmitting and receiving data between the device 100 ′ and each of the receivers 10 may be additionally provided. Here, the communication unit (not shown) may perform wired/wireless communication.

The plurality of receivers 10 (each receiver) is a received signal-related calculated value including the position of the satellite with respect to the visible satellite from the received signal received and collected from the plurality of receiving antennas 10' and a pseudorange measurement value as shown in Equation 1 May be calculated and provided (delivered) to the acquisition unit 20 of the device 100 ′ through wired/wireless communication through a communication unit (not shown).

The acquisition unit 20 may obtain a pre-processed pseudorange measurement value through pre-processing with respect to the calculated value related to the received signal provided (delivered) from the plurality of receivers 10. Thereafter, the estimating unit 30 may estimate the position (position, position vector) of each of the plurality of receivers 10 in consideration of the obtained preprocessed pseudorange measurement value and a predefined constraint condition.

According to this, in the apparatuses 100 and 100' and the systems 1000 and 1000', in order to estimate the position using a low-cost receiver, a plurality (at least three or more) of small and low-cost GNSS receiving antennas are used for the mobile body (platform). It may be disposed at a preset position, and a receiver corresponding to each of the disposed antennas may be disposed inside or outside the apparatuses 100 and 100', the main processing unit. Based on this, the apparatuses 100 and 100' and the systems 1000 and 1000' have only one main processing unit (the unit) based on the internal information of the receiver and the fixed distance information between the respective receivers as a constraint. It is possible to estimate the positions of all receivers (that is, each of all receivers considered in the present apparatus) (ie, a position for each receiver and a receiver clock error).

In other words, in the present application, reception including information related to the received signal collected in the L1 frequency band from a plurality of small, low-cost (consumer-grade) GNSS receivers (i.e., satellite position and pseudorange measurement values (code measurement values) for visible satellites) Signal-related calculation value), and the arrangement information between each receiver (this is information on the distance between each receiver, meaning the constraints related to the geometric arrangement structure of each receiver), and the main processing unit (this Device) (100, 100') can estimate the position and clock error of each receiver.

Hereinafter, a simulation result according to an experiment of the present application for evaluating the performance of the technology proposed by the present application (ie, a position estimation technology by the present system or the present apparatus, hereinafter referred to as the present position estimation technology) will be described.

5 is a diagram showing an example of an arrangement configuration of three receivers assumed in a simulation for performance evaluation of a position estimation apparatus using a plurality of receivers according to an embodiment of the present application.

Referring to FIG. 5, in an experiment of the present application, a simulation was performed with this position estimation technique assuming that three small and low-cost GNSS receivers are applied as a plurality of receivers 10 to the present apparatuses 100 and 100'.

)인 것으로 가정하였다.The satellite orbit and time settings for the simulation used ORBITAL PARAMETERS (Keplerian parameter) presented in RTCA-DO208 APPENDIX I, and the sampling period was set to 1 second and the simulation time was set from 07:20 to 1 hour. In addition, it is assumed that the measurement error of the pseudorange measurement value (i.e., the pseudorange measurement value of Equation 1) measured by each receiver disposed on the mobile object follows a Gaussian distribution, and the size of the measurement error is 1 m (1

).

It is assumed that the positions of each receiver (each of the three receivers) disposed on the mobile body are set as shown in Table 1 below, and it is assumed that each receiver is disposed as shown in FIG. 5.

The three receivers considered in one experiment of the present application may be referred to as receiver 1, receiver 2, and receiver 3. The distance between the receiver 1 and the receiver 2 and the distance between the receiver 2 and the receiver 3 may be set to about 2.1 m, respectively, and the distance between the receiver 1 and the receiver 3 may be set to about 2.7 m.

[Table 1]

In one experiment of the present application, in order to quantitatively analyze the position estimation accuracy of the present position estimation technology, a method mainly used in a commercially available small and low cost GNSS receiver was used as a reference value. This can be said to be a method of estimating the position of the receiver using the weighted least squares method without additional constraints by using the pseudorange measurement value (pseudo range measurement value) of the L1 frequency band for each receiver.

6 to 8 are diagrams showing simulation results according to an experiment of the present application made to evaluate the performance of a position estimation apparatus using a plurality of receivers according to an embodiment of the present application.

In particular, FIGS. 6 to 8 show horizontal/vertical position errors from receiver 1 to receiver 3, respectively. That is, FIG. 6 shows the horizontal/vertical position estimation error of the receiver 1, FIG. 7 shows the horizontal/vertical position estimation error of the receiver 2, and FIG. 8 shows the horizontal/vertical position estimation error of the receiver 3.

In FIGS. 6 to 8, blue indicates a reference value, and red indicates a position estimation result (that is, a position estimation result of the present position estimation technology) estimated by the apparatuses 100 and 100'.

6 to 8, it can be seen that the position estimation technology (that is, the present position estimation technology) by the present apparatus 100 and 100' shows an improvement in accuracy in the horizontal position error (the accuracy is improved). In the case of the vertical position error, it can be seen that the performance is similar to that of the reference value.

9 is a view showing another example of a simulation result according to an experiment of the present application made to evaluate the performance of a position estimation apparatus using a plurality of receivers according to an embodiment of the present application. In particular, FIG. 9 shows the horizontal position estimation error of three receivers (respective receivers).

Referring to FIG. 9, it can be seen that the position estimation technology (ie, the present position estimation technology) by the apparatuses 100 and 100 ′ improves the accuracy of horizontal position estimation compared to a reference value.

Meanwhile, Table 2 below shows the RMS value of the horizontal/vertical position error for each receiver. That is, Table 2 below shows the RMS horizontal/vertical position error of each receiver.

[Table 2]

Referring to Table 2 above, the position estimation results (i.e., position estimation values) by the device (100, 100') show similar performance compared to the reference value in the case of vertical position errors, while about 23% improvement in the case of horizontal position errors. It can be confirmed that it is.

Accordingly, the present application can provide the present apparatuses 100 and 100 ′ capable of estimating the exact position of the receiver by using a plurality of (three or more) low-cost small GNSS receivers.

In order to improve the low positioning accuracy of a single small, low-cost (consumer-grade) GNSS receiver, the present application uses geometric configuration information (distance) between each receiver (or each reception antenna disposed on the mobile body). The present apparatuses 100 and 100' which can improve the location accuracy of the receiver are proposed.

This application can be effectively applied to aircraft-mounted multi-band, small-sized 0.3m-class video radar, and ground big data analysis system. In addition, the present application can be easily applied (utilized) to satellite navigation positioning systems such as aviation, marine, autonomous driving platform position estimation, SAR platform position estimation, and complex navigation positioning system.

Conventional techniques for estimating the position of a platform (mobile, vehicle, etc.) using a small low-cost GNSS receiver have a problem that cannot be used for autonomous driving and SAR vibration compensation, as the estimated platform position accuracy is several meters. have. In order to solve this problem, various techniques such as differential satellite navigation, high-precision satellite navigation, and RTK have been developed to improve positional accuracy, but these conventional methods provide auxiliary information such as reference station receiver measurement information and precision satellite orbits from outside the receiver. It is difficult to replace a commercially inexpensive receiver because it is required or requires an expensive GNSS receiver or antenna.

Accordingly, in the present application, arrangement information between receivers (distance between receivers) is a fixed known value as a plurality of small and inexpensive receivers are mounted (arranged in a preset location) on a platform (mobile, vehicle, etc.) Therefore, based on this, the device (100, 100') improves the position accuracy of the receivers by estimating the position of each receiver using a weighted least squares method that takes a fixed distance between the receivers as a constraint in calculating the positions of the receivers. I can make it.

The present application may have an advantageous effect in terms of economy compared to a single expensive receiver. In addition, the present application may provide an effect of enabling accurate position estimation compared to a conventional single small and low cost (consumer-grade, commercial) GNSS receiver.

In addition, the present application provides more precise position, posture, and orientation information of the moving object when combined with a technique using two antennas or an auxiliary sensor such as an IMU to accurately estimate the azimuth information of the current moving object (platform). It can provide an estimable effect. In addition, since the present application utilizes a small and inexpensive GNSS receiver, a simple hardware configuration can be provided.

The present application utilizes the distance between each receiver (ie, the distance between antennas) as a constraint, and can accurately estimate the position of each receiver based on a technique of linearizing the distance between the receivers.

Hereinafter, based on the details described above, the operation flow of the present application will be briefly described.

10 is a flowchart illustrating a method for estimating a location using a plurality of receivers according to an embodiment of the present application.

The method for estimating a location using a plurality of receivers illustrated in FIG. 10 may be performed by the apparatuses 100 and 100 ′ described above. Accordingly, even if omitted below, the descriptions of the apparatuses 100 and 100' may be equally applied to the description of a method for estimating a position using a plurality of receivers.

Referring to FIG. 10, in step S11, the acquisition unit may acquire a preprocessed pseudorange measurement value from received signals collected by a plurality of receivers provided to correspond to each of a plurality of receiving antennas disposed on the mobile object.

Here, each of the plurality of receivers may calculate a received signal-related calculated value including a satellite position and a pseudorange measurement value for a visible satellite from a received signal received and collected from a receiving antenna provided to correspond to the receiver.

In addition, in step S11, the acquisition unit may obtain a preprocessed pseudorange measurement value by performing preprocessing of removing at least one of a satellite clock error, a tropospheric delay error, and an ionospheric delay error with respect to the calculated received signal-related calculated value.

Next, in step S12, the estimating unit may estimate the positions of each of the plurality of receivers in consideration of the pre-defined constraints associated with the plurality of receivers and the preprocessed pseudorange measurement value obtained in step S11.

At this time, the predefined constraints considered in step S12 are the first constraint on the distance between the plurality of receivers considering the positions of the plurality of receiving antennas arranged at the preset positions with respect to the moving object and the number of the plurality of receivers. It may include a second constraint.

Further, in step S12, the estimating unit may calculate a linearized indirect measurement value considering the number of visible satellites and a predefined constraint based on the pseudorange measurement value and the preprocessed pseudorange measurement value. Thereafter, in step S12, the estimating unit may estimate the positions of each of the plurality of receivers from the position estimation error vectors of the receivers included in the linearized indirect measurement values estimated using the weighted least squares method.

In the above description, steps S11 and S12 may be further divided into additional steps or may be combined into fewer steps, depending on the embodiment of the present application. In addition, some steps may be omitted as necessary, or the order between steps may be changed.

The method for estimating a location using a plurality of receivers according to an exemplary embodiment of the present disclosure may be implemented in the form of a program command 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 in the medium may be specially designed and configured for the present invention, or may be known and usable to those skilled in computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic media such as floptical disks. -A hardware device specially configured to store and execute program instructions such as magneto-optical media, and ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine language codes such as those produced by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like. The hardware device described above may be configured to operate as one or more software modules to perform the operation of the present invention, and vice versa.

In addition, the above-described method for estimating a position using a plurality of receivers 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 illustrative purposes only, and those of ordinary skill in the art to which the present application pertains will be able to 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 and non-limiting in all respects. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as being distributed may also be implemented in a combined form.

The scope of the present application is indicated by the claims to be described later rather than the detailed description, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present application.

100, 100': position estimation device using a plurality of receivers
10': multiple receiving antennas
10: multiple antennas
20: acquisition unit
30: estimation unit

Claims (11)

As a position estimation method using a plurality of receivers,
(a) obtaining a preprocessed pseudorange measurement value from received signals collected by a plurality of receivers provided to correspond to each of a plurality of receiving antennas disposed on the mobile body; And
(b) estimating the positions of each of the plurality of receivers in consideration of a pre-defined constraint with respect to the plurality of receivers and the obtained preprocessed pseudorange measurement value,
Position estimation method comprising a. The method of claim 1,
Each of the plurality of receivers in the step (a),
A method for estimating a location, comprising calculating a calculated value related to the received signal, including a satellite position and a pseudorange measurement value for a visible satellite, from a received signal received and collected from a receiving antenna provided to correspond to it. The method of claim 2,
The step (a),
To obtain the preprocessed pseudorange measurement value by performing a preprocessing of removing at least one of a satellite clock error, a tropospheric delay error, and an ionospheric delay error with respect to the calculated value related to the received signal. The method of claim 2,
In the step (b), the predefined constraint,
Including a first constraint on a distance between the plurality of receivers in consideration of the locations of the plurality of receiving antennas disposed at a preset location with respect to the mobile body and a second constraint on the number of the plurality of receivers, How to estimate your location. The method of claim 4,
The step (b),
Based on the pseudorange measurement value and the preprocessed pseudorange measurement value, a linearized indirect measurement value considering the number of visible satellites and the predefined constraint is calculated,
A method of estimating a position of each of the plurality of receivers from a position estimation error vector of a receiver included in the linearized indirect measurement value estimated using a weighted least squares method. A position estimation apparatus using a plurality of receivers,
An acquisition unit for acquiring a pre-processed pseudorange measurement value from received signals collected from a plurality of receivers provided to correspond to each of the plurality of receiving antennas disposed on the mobile body; And
An estimating unit for estimating a position of each of the plurality of receivers in consideration of the pre-processed pseudorange measurement value obtained and a constraint condition defined in relation to the plurality of receivers,
Position estimation device comprising a. The method of claim 6,
Each of the plurality of receivers,
The position estimation apparatus for calculating the received signal-related calculated value including a satellite position and a pseudorange measurement value for a visible satellite from a received signal transmitted from a receiving antenna provided to correspond to the received signal. The method of claim 7,
The acquisition unit,
To obtain the preprocessed pseudorange measurement value by performing preprocessing to remove at least one of a satellite clock error, a tropospheric delay error, and an ionospheric delay error with respect to the calculated values related to the received signals calculated by the plurality of receivers. Estimation device. The method of claim 7,
The predefined constraints are,
Including a first constraint on a distance between the plurality of receivers in consideration of the locations of the plurality of receiving antennas disposed at a preset location with respect to the mobile body and a second constraint on the number of the plurality of receivers, Position estimation device. The method of claim 9,
The estimation unit,
Based on the pseudorange measurement value and the preprocessed pseudorange measurement value, a linearized indirect measurement value considering the number of visible satellites and the predefined constraint is calculated,
A position estimation apparatus for estimating the positions of each of the plurality of receivers from a position estimation error vector of a receiver included in the linearized indirect measurement value estimated using a weighted least squares method. A computer-readable recording medium storing a program for executing the method of any one of claims 1 to 5 on a computer.

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