JP2019045499A - Positioning device, positioning method, positioning program, positioning program storage media, application device, and positioning system - Google Patents

Abstract

To achieve high precision positioning while receiving no positioning signal continuously from a paired plurality of positioning satellites.SOLUTION: A positioning device 10 includes a receiver 30 and a positioning operation unit 40. The receiver 30 detects a pseudo distance and a carrier wave phase integrated value of a positioning signal received at a plurality of times. The positioning operation unit 40 calculates a time difference value of the pseudo distance and the time difference value of the carrier wave phase integrated value. The positioning operation unit 40 sets an observation equation and a state equation using the time difference value. The positioning operation unit 40 performs positioning by executing filter operation using the observation equation and the state equation.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a positioning technique for performing single positioning using a GNSS positioning signal.

  Conventionally, various positioning devices for performing single positioning have been devised. For example, as shown in Patent Document 1, the positioning device receives a positioning signal of GNSS (Global Positioning Satellite Systems) such as GPS (Global Positioning System), and estimates a position using a pseudo distance and a carrier phase integrated value. Perform an operation.

  At this time, the positioning device performs a position estimation operation using a Kalman filter as shown in Patent Document 1. And in the conventional method using a Kalman filter, position estimation accuracy will fall by error factors, such as ionospheric delay and troposphere delay. Conventionally, in order to eliminate such error factors such as ionospheric delay and troposphere delay from the observation equation, the positioning apparatus conventionally uses a single phase difference between satellites, a single phase difference between receivers, or double satellites and receivers. The phase difference was used.

JP 2011-130399 A

  However, in the conventional configuration and method, it is necessary to continuously receive positioning signals from a plurality of paired positioning satellites, or require a plurality of receivers (antennas).

  Therefore, an object of the present invention is to provide a positioning device which realizes high-accuracy positioning by at least one receiver (antenna) without the need to continuously receive positioning signals from a plurality of paired positioning satellites. It is to do.

  A positioning device according to the present invention includes a receiving unit and a positioning operation unit. The receiver detects a pseudorange and a carrier phase integrated value of the positioning signal received at a plurality of times. The positioning operation unit calculates the time difference value of the pseudo range and the time difference value of the carrier phase integrated value. The positioning operation unit sets the observation equation and the state equation using the time difference value. The positioning operation unit performs positioning by performing filter operation using the observation equation and the state equation.

  In this configuration, if at least one positioning signal can be received at a plurality of times, the number of unknowns included in the observation equation decreases, and the positioning accuracy improves.

  Further, the positioning device of the present invention may have the following configuration. The positioning operation unit coordinates-converts the position to be measured from the WGS coordinate system to the local horizontal coordinate system when performing positioning of the moving body. The positioning operation unit applies a first-order Markov model of acceleration to the horizontal dynamic model, and applies a first-order Markov model of velocity to the dynamic model in the height direction.

  In this configuration, the equation of state for the mobile is set more appropriately.

  Further, the positioning device of the present invention may have the following configuration. The positioning operation unit includes a speed term in the horizontal dynamic model, and outputs the speed as the speed of the positioning target.

  In this configuration, the velocity is calculated along with the position.

  Further, the positioning device of the present invention may have the following configuration. The positioning operation unit includes a time difference value calculation unit, a double difference value calculation unit, and an abnormality detection unit. The time difference value calculation unit calculates the time difference value of the pseudo distance at a plurality of times. The double difference value calculation unit calculates a double time difference value with respect to time difference values of pseudo distances at a plurality of times. The abnormality detection unit detects an abnormality in reception of the positioning signal if the dual time difference value is equal to or more than the abnormality detection threshold.

  In this configuration, an observation abnormality, that is, an abnormality in reception of a positioning signal is easily detected.

  Furthermore, an application device of the present invention includes each component of the positioning device described in any of the above and an application processing unit. The application processing unit generates application information using the position calculated by the positioning operation unit.

  In this configuration, more accurate application information can be generated by obtaining highly accurate positioning results.

  The positioning system of the present invention also includes a base station and a positioning satellite. The base station includes each configuration of the positioning device described in any of the above and a correction information generation unit that generates correction information of satellite orbit information using the positioning result. The positioning satellite transmits the correction information from the correction information generation unit together with the positioning signal.

  In this configuration, by obtaining highly accurate correction information, more accurate positioning becomes possible.

  According to the present invention, highly accurate positioning can be realized by the extremely simple configuration and processing.

(A) is a block diagram which shows a structure of the positioning device which concerns on embodiment of this invention, (B) is a block diagram which shows the structure of a positioning calculating part. It is a flowchart which shows the positioning method which concerns on embodiment of this invention. It is a block diagram which shows the structure of the positioning calculating part in the case of performing abnormality detection. It is a flowchart of abnormality detection of observation value. It is a block diagram showing composition of a navigation device concerning an embodiment of the present invention. (A) is a figure which shows the structure of the correction system which concerns on embodiment of this invention, (B) is a block diagram which shows the structure of a base station.

  A positioning device and a positioning method according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1A is a block diagram showing the configuration of a positioning device according to an embodiment of the present invention, and FIG. 1B is a block diagram showing the configuration of a positioning operation unit.

  As shown in FIG. 1A, the positioning device 10 includes a receiving unit 30, a positioning operation unit 40, and a storage unit 50. The receiving unit 30 and the positioning operation unit 40 are each realized by one or more semiconductor elements or ICs. The receiving unit 30 and the positioning operation unit 40 can be realized by an information processing device and a program executed by the information processing device. The storage unit 50 is realized by a known storage medium such as a magnetic device or a semiconductor device. When the storage unit 50 is a semiconductor device, the storage unit 50 may be configured to be included in the positioning operation unit 40.

  The receiving unit 30 is connected to the antenna 20. The antenna 20 may be included in the positioning device 10.

  The antenna 20 receives positioning signals SS from a plurality of positioning satellites SAT (only one positioning satellite is illustrated in FIG. 1 and the other positioning satellites are omitted), and the receiving unit 30 receives the positioning signal SS. Output. The positioning signal SS is, for example, a positioning signal used in GNSS (Grobal Navigation Satellite Systems) such as a known GPS (Grobal Positioning System) signal.

  The receiving unit 30 captures and tracks the positioning signal SS to detect the pseudo distance ρ and the carrier phase integrated value Φ of the positioning signal SS. The receiver 30 detects the pseudo distance ρ and the carrier phase integrated value Φ of the positioning signal SS at a plurality of times. The receiving unit 30 outputs the pseudo distance ρ and the carrier phase integrated value Φ at each time to the positioning operation unit 40.

  The positioning operation unit 40 stores the pseudo distance お よ び and the carrier phase integrated value に in the storage unit 50. As shown in FIG. 1B, the positioning operation unit 40 includes a time difference value calculation unit 41 and a filter operation unit 42. The time difference value calculation unit 41 calculates the difference value (time difference value) Δρ of the pseudo distances ρ at a plurality of times. The time difference value calculation unit 41 calculates the difference value (time difference value) ΔΦ of the carrier wave phase integrated values 同 じ at the same plurality of times.

  The filter operation unit 42 sets the state equation and the observation equation according to the principle described below using the time difference value Δρ of the pseudo distance と and the time difference value ΔΦ of the carrier phase integrated value 、, and the Kalman filter Execute the process As a result, unknowns such as the ionospheric delay and the troposphere delay included in the observation equation disappear, and the positioning accuracy is improved.

  In addition, below, the case where L1 signal of a GPS signal is used as a positioning signal is demonstrated as an example.

  The observation model of the pseudo distance ((t) at time t is expressed by the following (Expression 1). This observation model is individually set for each of the plurality of positioning satellites SAT.

ρ (t) = r (t) + δI (t) + δT (t) + cδt (t)
+ Δ b _CA + e _CA (t) (Equation 1)
In equation (1), r (t) is the geometrical distance between the positioning device 10 and the positioning satellite SAT, δI (t) is the ionospheric delay, δT (t) is the tropospheric delay, δt (t) is a clock error of the positioning device 10 and positioning satellite SAT, [delta] b _CA is bias error to the code of the positioning device 10 and positioning satellite _{SAT, e} CA (t) is the observation error. C is the speed of light.

  Further, the observation model of the carrier phase integrated value ((t) at time t is expressed by the following (Equation 2). This observation model is individually set for each of the plurality of positioning satellites SAT.

((T) = r (t) −δI (t) + δT (t) + cδt (t)
+ Δ b _{L 1} + λ N + λ ε _{L 1} (t) (Expression 2)
In equation (2), r (t) is the geometrical distance between the positioning device 10 and the positioning satellite SAT, δI (t) is the ionospheric delay, δT (t) is the tropospheric delay, δt (t) Is a clock error of the positioning device 10 and the positioning satellite SAT, δb _L1 is a bias error with respect to the carrier phase of the positioning device 10 and the positioning satellite SAT, N is an integer bias with respect to the L1 signal, and ε _L1 (t) is It is an observation error. C is the speed of light.

  Here, time t1 and time t2 are set, and the time interval between time t1 and time t2 is set short. For example, the time interval is about 10 seconds or less. The time interval may be appropriately set according to the speed of the positioning satellite and the approximate moving speed of the positioning device, and may be, for example, about 3 seconds to 5 seconds. When the time interval between time t1 and time t2 is short, the moving distance of the positioning satellite and the positioning device is short. Therefore, it can be considered that the ionospheric delay δI (t1) at time t1 and the ionospheric delay δI (t2) at time t2 coincide with each other. Similarly, the tropospheric delay δT (t1) at time t1 and the tropospheric delay δT (t2) at time t2 can be considered to be coincident.

  Therefore, the difference value between the ionospheric delay δI (t1) and the ionospheric delay δI (t2) is approximately zero. Similarly, the difference value between the troposphere delay δT (t1) and the troposphere delay δT (t2) is also approximately zero.

  Further, since the time interval between time t1 and time t2 is short and the moving distance of the positioning satellite and the positioning device is small, it can be considered that the integer value bias at time t1 and the integer value bias at time t2 are the same.

  Further, it can be considered that the clock error and the bias error of the positioning device and the positioning satellite do not change at time t1 and time t2.

  Therefore, the time difference value Δρ (t1, t2) between the pseudo distance ((t1) at time t1 and the pseudo distance ((t2) at time t2 can be approximated by the following (Equation 3).

Δρ (t1−t2) = r (t1) −r (t2) + E _CA (t1, t2) (Expression 3)
E _CA (t1, t2) is an observation error of the code phase with respect to the time difference value Δρ of the pseudo distance.

  Similarly, the time difference value ΔΦ (t1, t2) between the carrier phase integrated value t (t1) at time t1 and the carrier phase integrated value ((t2) at time t2 can be approximated by the following (Equation 4) .

ΔΦ (t1−t2) = r (t1) −r (t2) + E _L1 (t1, t2) (Expression 4)
E _L1 (t1, t2) is an observation error of the carrier phase with respect to the time difference value ΔΦ of the carrier phase integration value.

  Here, r (t) is the distance between the positioning device 10 and the positioning satellite SAT, and the position of the positioning device 10 is u (t), the position of the positioning satellite SAT is Sp (t), and a symbol indicating distance calculation Is given by the following equation (5).

r (t) = DIS (u (t)-Sp (t)) (Equation 5)
The position Sp (t) of the positioning satellite SAT can be acquired by a navigation message superimposed on the positioning signal, information from a system (for example, MADOCA) in which other precise orbit information is provided, or the like.

  Therefore, by substituting (Eq. 5) into (Eq. 3) and (Eq. 4) described above, the time difference value .DELTA..rho. Of the pseudorange and the carrier phase difference integrated value with respect to the position u (t) of the positioning device 10 can be obtained. An observation model using the time difference value ΔΦ can be set. Then, using this observation model, it is possible to set an observation equation for the position of the positioning device 10 from known equation deformation.

  Also, the equation of state can be set as follows.

(A) Case of stationary state (static) In the case of stationary state, the positioning device 10 has not moved. Therefore, u (t _k ) = u (t _{k -1} ), and the state equation can be set.

  Therefore, the Kalman filter can be applied to the stationary state, and the position u (t) of the positioning device 10 can be estimated and calculated. If the observation error can be assumed to be white noise, a general Kalman filter theory may be used, and if the observation error is a colored noise, the Kalman filter theory having correlation with the state and observation noise may be used.

(B) In the case of the movement state (kinematic) In the case of the movement state, the movement model of the positioning device 10 is set by a primary approximation model using acceleration or velocity. Specifically, for example, settings are made as follows. First, the position u (t) is converted from the WGS coordinate system to the ENU coordinate system. This coordinate transformation can be realized by a known method.

  The movement model in the East direction and the North direction in the ENU coordinate system is set to an acceleration first-order Markov model. In addition, the movement model in the Up direction in the ENU coordinate system is set to a velocity first-order Markov model.

  Thereby, it is possible to set a state equation for the moving state.

  Therefore, the Kalman filter can be applied to the moving state, and the position u (t) of the positioning device 10 can be estimated and calculated.

  By using the above configuration and processing, error factors of the ionospheric delay, the troposphere delay, the clock error, and the bias error in the observation equation can be eliminated, and the estimation accuracy can be improved. In addition, the calculation is simplified by not using the single phase difference and the double phase difference. Furthermore, the positioning operation is possible with at least one antenna.

In the case of a moving state, when the time difference between the two times t _k-1 and t _k used in the Kalman filter is extremely small, a value corresponding to the distance difference r (t _k ) -r (t _k-1 ) is calculated. position _u (t k) for, u _{(t k-1)} gradient is multiplied by the vector _{G (t k-1),} G (t k) hardly changes. In this _case, the Kalman gain is reduced determined by _{G (t k) -G (t} k-1), may be estimated error becomes large.

In this case, with the position difference u (t _k ) −u (t _k−1 ) as the unknown, the gradient vector G (t _k−1 ), G (t _k ) are almost the same, and the gradient vector is used. The observation equation may be set using an average value (G (t _k-1 ) + G (t _k )) / 2 of This enables stable and highly accurate positioning.

  In addition, in the case of the movement state, the positioning device 10 can also calculate the velocity by using the term of the velocity included in the state equation.

  Moreover, although the aspect using one antenna was shown in the above-mentioned structure, you may use several antennas. In this case, the positioning device 10 performs the above-described positioning operation on each of the plurality of antennas. Then, the positioning device 10 may perform statistical processing such as an average value for the positions of the plurality of antennas. This makes it possible to further improve the position estimation accuracy.

  Moreover, in the above-mentioned description, the aspect which shared and performed each process by each function part was shown. However, each process described above may be programmed and stored in the storage unit 50 and executed by an arithmetic device such as a CPU. In this case, the process shown in FIG. 2 may be performed. FIG. 2 is a flowchart showing a positioning method according to an embodiment of the present invention.

  The arithmetic unit detects the pseudo distance 11 at the first time t1 and the carrier phase integrated value 11 (S101). The arithmetic unit detects the pseudo distance 22 at the second time t2 and the carrier phase integrated value 22 (S102).

  The arithmetic unit calculates a time difference value Δρ12 = ρ1−ρ2 between the pseudo distance 11 at the first time t1 and the pseudo distance 22 at the second time t2. Further, the arithmetic unit calculates a time difference value ΔΦ12 = Φ1-22 between the carrier phase integration value 11 at the first time t1 and the carrier phase integration value 22 at the second time t2 (S103).

  The arithmetic unit sets a state equation and an observation equation for estimating the position of the positioning apparatus, using the time difference value Δρ12 of the pseudorange and the time difference value ΔΦ12 of the carrier phase integrated value as the observation value (S104).

  The arithmetic unit executes Kalman filter processing on the state equation and observation equation set in step S104 to calculate the position of the positioning device (S105).

  In addition, in the above-mentioned positioning device and positioning method, abnormality detection is also possible to observation value. FIG. 3 is a block diagram showing the configuration of the positioning operation unit when detecting an abnormality.

  The positioning operation unit 40A includes a time difference value calculation unit 41, a double difference value calculation unit 43, and an abnormality detection unit 44. The time difference value calculation unit 41 calculates the difference value (time difference value) Δρ of the pseudo distances ρ at a plurality of times. The double difference value calculation unit 43 calculates a double difference value ΔΔρab between the time difference value Δρa and the time difference value Δρb obtained at different times. The abnormality detection unit 44 compares the double difference value Δρab with the threshold value Th for abnormality detection. If the double difference value Δρab exceeds the threshold value Th for abnormality detection, the abnormality detection unit 44 detects an abnormality in the observation value, that is, an abnormality in reception of the positioning signal.

  The abnormality detection process can also be realized by the arithmetic processing unit and the program as described above. FIG. 4 is a flowchart of abnormality detection of the observation value.

  The positioning operation unit 40 of the positioning device 10 calculates a double difference value ΔΔρ that is a further time difference value of the time difference value Δρ of the pseudo distance (S202). Specifically, as described above, the positioning operation unit 40 calculates the time difference value Δρ12 between the pseudo distance 11 at the first time t1 and the pseudo distance 22 at the second time t2. Further, the positioning operation unit 40 similarly calculates a time difference value Δρ23 between the pseudo distance 22 at the second time t2 and the pseudo distance 33 at the third time t3. The positioning operation unit 40 calculates a double difference value ΔΔρ between the time difference value Δρ23 and the time difference value Δρ12. In addition, in this description, although the pseudo | simulation distance of the same time is contained in two time difference values, it does not restrict to this.

  The positioning operation unit 40 compares the double difference value ΔΔρ with the threshold value Th for abnormality detection (S202). The threshold value Th for abnormality detection is set based on the amount of change of the time difference value when it has deteriorated beyond the required positioning accuracy with reference to the positioning result and the like already acquired.

  If the double difference value ΔΔρ exceeds the threshold value Th (S202: YES), the positioning operation unit 40 determines that the pseudo distance which is the observation value is abnormal (S203).

  If the double difference value ΔΔρ does not exceed the threshold value Th (S202: NO), the positioning operation unit 40 determines that the pseudo distance which is the observation value is normal (S204).

  As described above, by using the configuration and processing of the present embodiment, it is possible to detect an abnormality of the observed value. Although this description shows the case of the pseudo distance, it is possible to detect an abnormality even by using the carrier phase integrated value.

  The above-mentioned positioning device can be applied to various application devices using the position of the device itself. For example, FIG. 5 is a block diagram showing the configuration of the navigation device according to the embodiment of the present invention.

  As shown in FIG. 5, the navigation device 1 includes a positioning device 10, an antenna 20, and a navigation processing unit 61. The navigation device 1 corresponds to the "application device" of the present invention, and the navigation processing unit 61 corresponds to the "application processing unit" of the present invention.

  The positioning device 10 and the antenna 20 have the above-described configuration. The positioning operation unit 40 outputs the positioning result to the navigation processing unit 61.

  The navigation processing unit 61 generates navigation information such as route inquiry to a target position of a mobile body on which the own device is mounted, route guidance, peripheral information of the current position, and the like from a known method to which the positioning result is applied. The navigation processing unit 61 displays navigation information on a display unit (not shown) or the like. Here, by using the positioning device 10 of the present embodiment, the own device position can be obtained with high accuracy, so the navigation device 1 can provide highly accurate route inquiry, route guidance, and more appropriate peripheral information.

  In the above description, although the aspect of calculating the position of the positioning device is shown, it is also possible to provide the positioning device in a base station and calculate the position of the positioning satellite with high accuracy using the above estimation operation. . Then, by using this calculation result, it is also possible to calculate correction information for the satellite orbit information. FIG. 6A is a diagram showing a configuration of a correction system according to an embodiment of the present invention, and FIG. 6B is a block diagram showing a configuration of a base station.

  As shown in FIGS. 6A and 6B, the base station 2 includes a positioning device 10, an antenna 20, a transmission antenna 20T, a correction information generation unit 71, and a transmission unit 72. The antenna 20 and the positioning device 10 have the above-described configuration. The positioning operation unit 40 outputs the positioning result to the correction information generation unit 71.

  The correction information generation unit 71 stores in advance the position of the base station 2 (reference position for correction). The correction information generation unit 71 compares the correction reference position with the positioning position. The correction information generation unit 71 calculates an error of the satellite position from the comparison result of the reference position for correction and the positioning position using a known method. The correction information generation unit 71 generates correction information of satellite orbit information from the error of the satellite position. The correction information generation unit 71 outputs the correction information to the transmission unit 72.

  The transmitting unit 72 transmits the correction information to the positioning satellite SAT via the transmitting antenna 20T. The positioning satellite SAT updates the correction information according to the received correction information.

  By using such a system configuration, correction information can be updated with high accuracy, and positioning accuracy is improved.

1: Navigation device 2: Base station 10: Positioning device 20: Antenna 30: Reception unit 40: Positioning operation unit 41: Time difference value calculation unit 42: Filter operation unit 43: Double difference value calculation unit 44: Abnormality detection unit 50 : Storage unit 61: Navigation processing unit 71: Correction information generation unit 72: Transmission unit 20T: Transmission antenna SAT: Positioning satellite SS: Positioning signal

Claims (9)

A receiver configured to detect a pseudorange and a carrier phase integrated value of positioning signals received at a plurality of times;
An observation equation and a state equation are set using the time difference value of the pseudo distance and the time difference value of the carrier phase integrated value, and positioning is performed by executing a filter operation using the observation equation and the state equation. A positioning operation unit,
A positioning device comprising: The positioning operation unit
When performing positioning of a mobile body, coordinate conversion of the position to be measured from the WGS coordinate system to the local horizontal coordinate system,
The horizontal dynamic model applies the first-order Markov model of acceleration, and the vertical dynamic model applies the first-order Markov model of velocity,
The positioning device according to claim 1. The positioning operation unit
The horizontal dynamic model includes speed terms,
Output the speed as the speed of the positioning target
The positioning device according to claim 2. The positioning operation unit
A time difference value calculation unit that calculates time difference values of the pseudo distance at a plurality of times;
A double difference value calculation unit that calculates a double time difference value with respect to time difference values of the pseudo distances of the plurality of times;
An abnormality detection unit that detects an abnormality in reception of the positioning signal if the double time difference value is equal to or greater than an abnormality detection threshold;
Equipped with
The positioning device according to any one of claims 1 to 3. A configuration of the positioning device according to any one of claims 1 to 4, and
An application processing unit that generates application information using the position calculated by the positioning operation unit;
An application device comprising: A base station comprising: each configuration of the positioning device according to any one of claims 1 to 4; and a correction information generation unit configured to generate correction information of satellite orbit information using a result of the positioning;
A positioning satellite that transmits the correction information from the correction information generation unit together with the positioning signal;
A positioning system, comprising: Detecting pseudoranges and carrier phase integrated values of positioning signals received at multiple times;
Calculating a time difference value of the pseudo distance and a time difference value of the carrier phase integrated value;
Setting an observation equation and a state equation using the time difference value,
Positioning is performed by performing a filter operation using the observation equation and the state equation
Positioning method. A process of detecting pseudoranges and carrier phase integrated values of positioning signals received at multiple times;
A process of calculating a time difference value of the pseudo distance and a time difference value of the carrier phase integrated value;
A process of setting an observation equation and a state equation using the time difference value;
A process of performing positioning by performing a filter operation using the observation equation and the state equation;
A positioning program that causes an arithmetic processing unit to execute A process of detecting pseudoranges and carrier phase integrated values of positioning signals received at multiple times;
A process of calculating a time difference value of the pseudo distance and a time difference value of the carrier phase integrated value;
A process of setting an observation equation and a state equation using the time difference value;
A process of performing positioning by performing a filter operation using the observation equation and the state equation;
A positioning program storage medium storing a program that causes an arithmetic processing unit to execute the program.

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