JP2007278881A - Mobile body-mounted positioning device and its positioning method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mobile body-mounted positioning device reduced in size and simplified by performing positioning computation only data from a GNSS satellite even when the number of satellite from which positioning data can be received is insufficient in the mobile body-mounted positioning device. <P>SOLUTION: When there is deficiency in the number of satellites from which the positioning data can be received, a current velocity vector of a vehicle 1 is estimated from the positioning data in the past, it is assumed that the vehicle 1 travels on a straight line 30 obtained by extending the velocity vector, and the positioning position of the vehicle 1 is specified using a distance ρ<SB>1</SB>between the GNSS satellite 20 and the vehicle 1 obtained from GNSS data. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an apparatus and a method for calculating coordinates of a moving body based on a signal from a GNSS positioning apparatus.

  2. Description of the Related Art Conventionally, GNSS (Global Navigation Satellite System) using artificial satellites has been adopted as a positioning system for automobiles and aircraft. Artificial satellites used in this GNSS transmit coded data signals of distance timing and accurate satellite position. Then, the estimated position of the vehicle equipped with the GNSS receiver can be obtained by precisely measuring each time when the coded signal transmitted by each GNSS satellite reaches the GNSS receiver mounted on the vehicle. (For example, refer to Patent Document 1). In order to perform three-dimensional positioning on the earth using this GNSS, there are four unknowns that need to be solved by positioning calculation: clock error and x, y, z coordinates. It is necessary to receive the data signal.

On the other hand, if the clock error δt or the like is known, the number of unknowns in the calculation of the positioning position is reduced by one, so that the number of data from the satellite necessary for positioning can be reduced by one. In this case, as shown in FIG. 6, it is possible to calculate the positioning of the moving body 1 by using the distance data ρ ₁ , ρ ₂ , ρ ₃ between the vehicle 1 on the earth and the three satellites 20, 21, 22 respectively. . However, if the number of satellites that can receive data further decreases on the ground with many obstacles such as urban areas and mountainous areas, the order of the equations that can be solved from the positioning position data will decrease. It has been necessary to use the inertial navigation positioning method together (for example, see Patent Document 2).

JP 2001-56234 A Japanese Patent Laid-Open No. 61-137090

  However, as described above, the number of GNSS satellites that can receive data is small, and the period during which inertial navigation is required is limited. After this limited period, the GNSS satellite moves by data from a normal GNSS satellite. Body positioning calculation can be performed. Incorporation of an inertial navigation device and a data processing system for dealing with such a limited period has a problem that the device for calculating the coordinates of the moving body becomes large and complicated.

  Accordingly, an object of the present invention is to reduce the size of a positioning device mounted on a mobile unit by performing positioning calculation using only data from a GNSS satellite even during a period when the number of satellites capable of receiving position data is insufficient. The purpose is to simplify.

  A mobile unit-mounted positioning device according to the present invention includes a GNSS receiving unit mounted on a mobile unit that receives a signal from a GNSS satellite, a data storage unit mounted on the mobile unit that stores positioning data, and the GNSS receiving unit. And a calculation unit that takes in signals from the data storage unit and performs calculation processing, and an output unit connected to the calculation unit, the calculation unit stores the data in the data storage unit An estimated velocity vector of the moving object is calculated based on past positioning data, the position of the moving object is limited on a straight line obtained by extending the estimated velocity vector, and the moving object is determined based on a received signal from the GNSS satellite. It has the means to calculate the position of.

  A mobile unit-mounted positioning device of the present invention includes a GNSS receiving unit mounted on a mobile unit that receives a signal from a GNSS satellite, and a data storage mounted on the mobile unit that stores positioning data and stores a map database. In the mobile body-mounted positioning device, comprising: a unit, a calculation unit that takes in signals from the GNSS reception unit and the data storage unit, and an output unit connected to the calculation unit, the calculation unit includes: Based on the past positioning data stored in the data storage unit and the map database, the moving path where the moving body is located in the map database is specified, and the position of the moving body is limited to the moving path, and the GNSS It has the means to calculate the position of a moving body based on the received signal from a satellite, It is characterized by the above-mentioned.

  According to the mobile positioning method of the present invention, the GNSS receiving unit receives a signal from a GNSS satellite, takes the GNSS signal and past positioning data stored in the data storage unit into the arithmetic unit, and the past positioning data. Based on the above, the estimated velocity vector of the moving object is calculated, the position of the moving object is limited on a straight line obtained by extending the estimated velocity vector, and the position of the moving object is calculated based on the received signal from the GNSS satellite. It is characterized by doing.

  In the mobile positioning method of the present invention, a signal from a GNSS satellite is received at a GNSS receiving unit, the GNSS signal and past positioning data stored in a data storage unit are taken into a calculation unit, and the past positioning is performed. Based on the data and the map database, the moving path in which the moving body is located in the map database is specified, the position of the moving body is limited to the moving path, and the moving body is based on the received signal from the GNSS satellite. Calculating the position of.

  The present invention achieves downsizing and simplification of a positioning device mounted on a mobile body by performing positioning calculation only with data from a GNSS satellite even during a period when the number of satellites capable of receiving position data is insufficient. There is an effect that can be.

  Hereinafter, preferred embodiments of the present invention will be described with reference to FIGS. FIG. 1 is a system diagram showing the configuration of this embodiment, FIG. 2 is a flowchart showing the operation of this embodiment, and FIG. 3 is a diagram schematically showing the positioning calculation method of this embodiment. The mobile body-mounted positioning device 3 of the present embodiment includes a GNSS antenna 10 mounted on a vehicle 1 that is a mobile body, a GNSS receiver 12 that is connected to the GNSS antenna 10 and receives signals from the GNSS antenna 10, and positioning data. A data storage unit 16 storing map data information, a signal from the GNSS receiving unit 12, a calculation unit 14 for performing positioning calculation of the vehicle 1 based on the data from the data storage unit 16, and a calculation unit 14 And a display unit 18 for outputting the calculated position. The GNSS receiving unit 12 and the data storage unit 16 are respectively connected to the calculation unit 14 via a signal line or a data bus, and the display unit 18 is also connected to the calculation unit 14 via a signal line or a data bus.

  In the normal state as shown in FIG. 6, even if the clock error δt is known, at least a three-dimensional matrix operation is performed to obtain three unknowns (x, y, z) of three-dimensional coordinates. In order to establish a three-dimensional matrix calculation formula, data from three satellites is required. The GNSS receiver 12 receives data signals from three or four GNSS satellites via the GNSS antenna 10 and outputs the data to the calculator 14. Based on the data received from the GNSS receiving unit 12, the calculation unit 14 performs positioning calculation of the vehicle 1, obtains the three-dimensional coordinates (x, y, z) of the vehicle on the earth 5, and outputs it to the display unit 18. At the same time, the positioning data at that time is output to the data storage unit 16 and stored and accumulated as past positioning data in the data storage unit. The amount of data to be stored may be from the positioning calculation result how many times before the positioning calculation is performed, or may be determined as many minutes before the positioning calculation is performed. In addition, if the driving condition is analyzed based on the accumulated positioning data and it is determined that the vehicle is traveling on a route with many curves, the positioning data for a long time may be accumulated, or the time interval for data accumulation may be increased. If it is determined that the vehicle is shortening or traveling on a route close to a straight line, the data is stored in the data storage unit 16 in a format such as increasing the data storage time interval.

As shown in FIG. 5, when there is only one satellite that can receive position data due to the influence of topography, buildings, etc., the clock error δt is known as described above. However, a three-dimensional matrix arithmetic expression cannot be established, and only a one-dimensional arithmetic expression can be established. Therefore, it is necessary to reduce the dimension of the calculation matrix for positioning calculation to one dimension. The data storage unit 16 stores the positioning data until just before the number of satellites that can receive the distance data becomes one by the predetermined method as described above. The calculation unit 14 first reads the past positioning data from the data storage unit 16 and estimates the current speed vector of the vehicle 1. Then, as shown in FIG. 3, a straight line 30 obtained by extending the speed vector is specified, and it is estimated that the vehicle 1 is traveling on the straight line 30. Then, as shown in FIG. 3, by using the distance data ρ ₁ between the GNSS satellite 20 and the vehicle 1, a solution can be obtained by solving the one-dimensional arithmetic expression, and the positioning position of the vehicle 1 can be specified. .

The calculating part 14 performs the positioning calculation of the vehicle 1 by a method as shown in FIG. As in step S <b> 102 of FIG. 2, the calculation unit 14 acquires a position signal from the GNSS satellite 20 received by the GNSS reception unit 12. Then, as shown in step S103 of FIG. 2, the calculation unit 14 calculates the coordinates of the GNSS satellite 20 shown in FIG. 3 based on this signal, and calculates the distance ρ ₁ between the vehicle 1 and the GNSS satellite 20. Next, as shown in step S <b> 104 of FIG. 2, the calculation unit 14 reads past positioning data from the data storage unit 16, and calculates an estimated speed vector of the vehicle 1 based on the past positioning data. In addition to the method of calculating the estimated velocity vector from the past data by the least square method, there is also a method of calculating by the Kalman filter. In many cases, such a calculation method uses a convergence calculation method. When the travel route that can be calculated from the past positioning data of the vehicle 1 is not so complicated, the calculation converges in a short time and a calculation solution of the estimated speed vector is obtained. On the other hand, when the vehicle 1 is traveling on a complicated route, the calculation may not converge from the accumulated past positioning data, and the velocity vector may not be estimated. As shown in step S105 of FIG. 2, when a calculation solution of the estimated speed vector is obtained, the calculation unit 14 specifies a straight line 30 obtained by extending the estimated speed vector as shown in step S106 of FIG. Then, as shown in step S107 of FIG. 2, it is assumed that the vehicle 1 is on the specified straight line 30, and a one-dimensional equation is solved using the distance ρ ₁ between the vehicle 1 and the GNSS satellite 20, and the vehicle 1 Find the position of 1. As shown in FIG. 3, if the distance ρ ₁ between the GNSS satellite 20 and the vehicle ₁ is determined, assuming that the position of the vehicle is on the specified straight line 30, the position of the vehicle 1 on the straight line 30 is one point. Specified. When the position of the vehicle 1 is specified, the calculation unit 14 displays the result on the display unit 18. On the other hand, as shown in step S105 of FIG. 2, when the calculation solution of the estimated speed vector of the vehicle 1 cannot be obtained from the past positioning data, the calculation unit 14 stops the positioning calculation, and the number required for the positioning calculation Wait until data from the GNSS satellite can be received.

  If the number of satellites that can receive data becomes three or four, which allows the normal positioning calculation described above, as a result of the vehicle 1 running continuously, the calculation unit 14 performs the normal positioning. The vehicle 1 is positioned by the method, and the positioning data is displayed on the display unit 18 and stored in the storage unit 16.

  In the embodiment described above, even when the number of satellites that can receive data is smaller than the required number, the position of the vehicle 1 is determined by using only the GNSS device and its data without using an inertial navigation device or the like. When the number of satellites that can receive data has returned to the required number, the position of the vehicle 1 can be measured by ordinary three-dimensional positioning, so that the number of satellites that can receive data is less than the required number. It is not necessary to install an inertial navigation device or the like separately in case of an emergency. For this reason, there exists an effect that the positioning apparatus mounted in a vehicle can be reduced in size and simplified.

  In the above embodiment, the estimated speed vector is calculated from the past positioning data, and the position of the vehicle 1 is calculated on the assumption that the vehicle 1 is on the straight line 30 obtained by extending the estimated speed vector. In many cases, since the distance that the car travels within the positioning time interval is very small compared to the distance to the GNSS satellite, the vehicle 1 may have a large error even if it is on a straight line obtained by extending the estimated speed vector. Since the number of GNSS satellites that can receive data returns to the number that can perform normal positioning calculation while the error is small, the positioning position is not greatly displaced from the actual position. However, for example, when the vehicle 1 is complicatedly turning around an intersection or traveling on a road with many curves, the error may increase in the above embodiment.

Another embodiment of the present invention suitable for a case where the movement of the vehicle is complicated will be described with reference to FIGS. FIG. 4 is a flowchart showing the operation of another embodiment, and FIG. 5 is a diagram schematically showing a positioning calculation method of another embodiment. The same parts as those of the previous embodiment are denoted by the same reference numerals, and description thereof is omitted.

When the vehicle 1 travels along a complicated route, the travel route is not a straight line but a curved line. In this case, it is possible to predict a traveling curve based on past positioning data and perform positioning calculation assuming that the vehicle 1 is positioned on the curved line. However, the vehicle 1 travels along a ground road. Therefore, in the above method, the shape of the road is predicted from the past positioning data. However, since the shape of the road is difficult to predict mathematically, the positioning accuracy of the vehicle 1 falls. Therefore, map data is stored in the data storage unit 16, and the road on which the vehicle 1 is traveling is based on the positioning data when the number of satellites that can receive the data is the number necessary for normal positioning. To identify. And the candidate of the positioning position of the vehicle 1 is calculated using the distance data ρ ₁ between the GNSS satellite 20 and the vehicle 1 as shown in FIG. As shown in FIG. 5, when traveling on a road or moving route indicated by the curve 32, the curve 32 is two-dimensional, so that the position of the vehicle is determined from at least two satellites. Data is required. However, when the number of satellites that can receive data is one, the number of equations is reduced with respect to the unknown, so the point where the distance between the vehicle 1 and the satellite is ρ ₁ cannot be specified, and there are a plurality of points. . Therefore, among the plurality of position candidates, the one closest to the past positioning data or the one closest to the predicted traveling curve calculated from the past positioning data is set as the positioning position of the vehicle 1, and the display unit 18 is displayed.

The calculating part 14 performs the positioning calculation of the vehicle 1 by a method as shown in FIG. First, as in the previous embodiment, a distance ρ ₁ between the vehicle 1 and the GNSS satellite 20 is calculated. Next, as shown in step S204 of FIG. 4, the calculation unit 14 reads the past positioning data and the map database from the data storage unit 16, and specifies the position of the vehicle 1 on the map database based on the past positioning data. Then, the road on which the vehicle 1 is traveling from that position is specified as a curve 32 shown in FIG. When the curve 32 is identified, as shown in step S206 of FIG. 4, vehicle 1 as being above the curve 32 identified above, the vehicle 1 by using the distance [rho ₁ of the vehicle 1 and the GNSS satellites 20 A plurality of position candidates are calculated. Then, the calculation unit 14 specifies, as the position of the vehicle 1, a position closest to the most recent positioning position from among the plurality of candidates or a position closest to the curve estimated from past positioning data. When the position of the vehicle 1 is specified, the calculation unit 14 displays the result on the display unit 18. On the other hand, as shown in step S205 of FIG. 4, when the movement route of the vehicle 1 cannot be specified from the past positioning data, the calculation unit 14 stops the positioning calculation, and from the number of GNSS satellites necessary for the positioning calculation. Wait until data is received. Note that, even when the position of the vehicle 1 cannot be identified from one of a plurality of candidate positions even by the above method, the calculation unit 14 outputs and displays the plurality of position candidates as estimated position candidates on the output unit 18.

  The other embodiments described above also have the effect that the positioning device mounted on the vehicle can be reduced in size and simplified as in the previous embodiment.

  The present invention can be applied to any movable body that moves on the earth other than positioning of the vehicle.

It is a systematic diagram which shows the structure of embodiment of this invention. It is a flowchart which shows operation | movement of embodiment of this invention. It is the figure which represented typically the positioning calculation method of embodiment of this invention. It is a flowchart which shows operation | movement of other embodiment of this invention. It is the figure which represented typically the positioning calculation method of other embodiment of this invention. It is the figure which represented typically the positioning calculation method by the GNSS satellite of a prior art.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Vehicle, 3 mobile-mounted positioning apparatus, 5 earth, 10 GNSS antenna, 12 GNSS receiving part, 14 calculating part, 16 data storage part, 18 display part, 20-22 GNSS satellite, 30 straight line, 32 curve.

Claims (4)

A GNSS receiver mounted on a mobile body that receives a signal from a GNSS satellite;
A data storage unit mounted on the mobile body for storing positioning data;
A calculation unit that takes in signals from the GNSS reception unit and the data storage unit and performs calculation processing;
In the mobile body mounted positioning device comprising an output unit connected to the arithmetic unit,
The calculation unit calculates an estimated speed vector of the moving body based on past positioning data stored in the data storage unit, and limits the position of the moving body on a straight line obtained by extending the estimated speed vector. Having means for calculating the position of the moving body based on the received signal from the GNSS satellite;
A mobile device-mounted positioning device. A GNSS receiver mounted on a mobile body that receives a signal from a GNSS satellite;
A data storage unit mounted on the mobile body storing the positioning data and storing the map database;
A calculation unit that takes in signals from the GNSS reception unit and the data storage unit and performs calculation processing;
In the mobile body mounted positioning device comprising an output unit connected to the arithmetic unit,
The calculation unit identifies a moving path where the moving body is located in the map database based on the past positioning data stored in the data storage unit and the map database, and sets the position of the moving body on the moving path. Limited to have means for calculating the position of the mobile based on the received signal from the GNSS satellite;
A mobile device-mounted positioning device. In a mobile positioning method based on a received signal from a GNSS satellite,
The GNSS receiver receives a signal from a GNSS satellite,
The GNSS signal and past positioning data stored in the data storage unit are taken into the calculation unit,
Based on the past positioning data, the estimated velocity vector of the moving object is calculated, the position of the moving object is limited on a straight line obtained by extending the estimated velocity vector, and the moving object moves based on the received signal from the GNSS satellite. Calculating the position of the body,
A positioning method for a moving object. In a mobile positioning method based on a received signal from a GNSS satellite,
The GNSS receiver receives a signal from a GNSS satellite,
The GNSS signal and past positioning data stored in the data storage unit are taken into the calculation unit,
Based on the past positioning data and the map database, the moving path in which the moving body is located is specified in the map database, the position of the moving body is limited to the moving path, and the received signal from the GNSS satellite is used. Calculating the position of the moving body based on,
A positioning method for a moving object.

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