JP2020112494A - Satellite selection device, and program - Google Patents

Abstract

To enable the selection of a satellite which can calculate the position or the speed of a moving body on the earth with high accuracy in the case of calculating at least one of the position and speed of the moving body on the earth.SOLUTION: A satellite information acquisition unit (31) acquires information of a GPS satellite, an antenna position and receiver time error calculation unit (32) calculates respective positions of GPS antennas (12A, 12B) on the basis of the satellite information, an estimated pseudo distance calculation unit (34) calculates a distance to each GPS satellite for each GPS antenna, a pseudo distance residual error calculation unit (35) calculates a difference between an observed distance and an estimated distance for each GPS antenna, and an excluded satellite discrimination unit (37) excludes a GPS satellite on the basis of the distance between the observed distance and the estimated distance.SELECTED DRAWING: Figure 1

Description

The present invention relates to a satellite selection device and a program.

Conventionally, when receiving signals from multiple satellites and calculating its own position, position detection that calculates its own position without using some satellite signals among the signals from multiple satellites A device is known (Patent Document 1). In this position detecting device, the receiver that receives the signal from the satellite, and the Doppler frequency generated by the relative velocity with the satellite, the difference between the measured value and the predicted value while the receiver is stationary becomes a threshold value or more It calculates its position without using the signal from.

There is also known a navigation satellite receiver that calculates the distance from a satellite to a receiver and calculates the position of the receiver without using the distance calculated for some satellites (Patent Document 2). .. In this navigation satellite receiver, the distance predicted from the satellite to the receiver is used as an approximate distance, and the satellite to the receiver is calculated based on the time difference between the transmission time at which the signal was transmitted from the satellite and the time at the receiver that received the signal. The calculated distance is obtained as a pseudo distance. The position of the receiver is calculated without using the approximate distance and the pseudo distance for a satellite in which the difference between the pseudo distance and the approximate distance (hereinafter referred to as the pseudo distance residual) exceeds the threshold value.

JP, 11-118903, A JP, 2003-57327, A

However, in the case of receiving signals from a plurality of satellites and calculating the position of itself, it is affected by multipath in which a signal reflected from a building or the like and a direct signal from the satellite are mixed. In Patent Document 1, when the difference between the measured value and the predicted value of the Doppler frequency is equal to or more than the threshold value, it is determined that the influence of the multipath is exerted, and the signal from the satellite is not used. Calculate the position of. At this time, a method of setting a threshold according to the speed of the moving body has been proposed. However, since it is irrelevant whether or not the velocity of the mobile body is in a multipath environment, it is difficult for this method to set an appropriate threshold value considering the prediction error of the Doppler frequency due to the influence of multipath. For example, if the threshold value is too large, satellites with large multipath errors cannot be excluded. If the threshold value is too small, satellites that are not affected by multipath may be excluded.

Further, the above-mentioned Patent Document 2 describes that the position of the receiver is calculated in consideration of the influence of multipath. However, when there is a large error in the obtained pseudorange residual, it is difficult to determine whether or not the error is affected by multipath, and thus it is difficult to set an appropriate threshold value.

Here, the pseudo distance includes a distance error caused by an estimation error of the receiver position and an estimation error of the receiver time difference. To suppress the estimation error of the receiver time difference, do not use the pseudorange residual as it is, but use the pseudorange residual of the satellite with the highest elevation angle as the reference value, and the reference value of the pseudorange residual and each satellite. It is conceivable to discriminate satellites having a large pseudo-range error affected by multipath based on the difference from the pseudo-range residual (difference of pseudo-range residual). Since the error of the receiver time difference is common to each satellite, it is possible to exclude the influence of the error of the receiver time difference.

On the other hand, the receiver position estimation error does not have a common influence on the calculation accuracy of the pseudorange residual with each satellite. For example, if a position error occurs in the direction of approaching the satellite with the highest elevation angle, the pseudorange residual with the satellite with the highest elevation angle will be small, while the pseudorange residual with other satellites will be large. There is a nature. Therefore, it is difficult to reduce the influence of the accuracy of position estimation.

The present invention has been made in consideration of the above facts, and provides a satellite selection device and a program capable of selecting a satellite that can be accurately calculated when determining at least one of the position and speed of the moving body on the earth. The purpose is to do.

In order to achieve the above object, the first aspect of the present disclosure is a positioning device that calculates a position on the earth of a positioning target position in a mobile body that is different from installation positions of a plurality of satellite antennas installed in the mobile body. A satellite selection device for selecting a satellite to be used, the information relating to the position of each of the plurality of satellites transmitted from each of the plurality of satellites, and the distance between each of the plurality of satellites and the mobile body. Based on the satellite information acquisition unit that acquires satellite information including information, and the satellite information acquired by the satellite information acquisition unit, the plurality of satellites observed at each installation location of the plurality of satellite antennas. An observation pseudorange deriving unit that derives observation pseudorange information indicating a distance between each of the plurality of satellite antennas and each of the plurality of satellite antennas, and a predetermined location of each of the plurality of satellite antenna installation locations and the positioning target location. Based on the positional relationship and the satellite information acquired by the satellite information acquisition unit, each of the plurality of satellites, and each of the plurality of satellite antennas at each position from the positioning target location calculated. Between the satellites of the plurality of satellite antennas for each of the plurality of satellites, the estimated pseudo-range calculator that estimates estimated pseudo-range information indicating the distance between the observation pseudo-range deriving unit. Each of the plurality of satellite antennas derived by the residual derivation unit that derives a residual between the observed pseudorange information and the estimated pseudorange information estimated by the estimated pseudorange calculation unit, and the residual derivation unit. And a satellite selection unit that selects a satellite to be excluded from the satellites to be used based on the difference of the residual.

A second aspect of the present disclosure is the satellite selecting apparatus according to the first aspect, wherein the satellite selecting unit excludes satellites corresponding to the difference of the residuals equal to or more than a predetermined threshold from the satellites to be used.

A third aspect of the present disclosure is the satellite selection device according to the first aspect or the second aspect, further including a reliability determination unit that determines the reliability of each time error of the receivers of the plurality of satellite antennas, The satellite selection unit selects a satellite to be excluded from the satellites to be used, based on the difference between the residuals of the plurality of satellite antennas only when the reliability determination unit determines that the reliability is high. To do.

According to a fourth aspect of the present disclosure, in the satellite selection device according to the third aspect, the reliability determination unit determines which one of the residuals derived by the residual deriving unit for a plurality of predetermined different satellites. When the residual error of one satellite antenna is within a threshold value with respect to the residual error of another satellite antenna, it is determined that the reliability of the time error of the receiver is high.

A fifth aspect of the present disclosure is a satellite that selects a satellite to be used in a speed measurement device that calculates a speed on the earth of a positioning target location in the mobile body that is different from installation locations of a plurality of satellite antennas installed in the mobile body. A satellite information including a position information of each of the plurality of satellites transmitted from each of the plurality of satellites and a relative speed between each of the plurality of satellites and the moving body. Based on the satellite information acquisition unit to be acquired and the satellite information acquired by the satellite information acquisition unit, each of the plurality of satellites observed at each installation location of the plurality of satellite antennas, and the plurality of satellites. An observational Doppler frequency deriving unit that derives observed Doppler frequency information indicating the relative speed between each of the satellite antennas, a speed relationship between the installation location of each of the plurality of satellite antennas and the positioning target location, and the satellite information. Based on the satellite information acquired by the acquisition unit, each of the plurality of satellites, an estimated Doppler frequency calculation unit for estimating estimated Doppler frequency information indicating the relative speed between each of the plurality of satellite antennas, and , For each of the plurality of satellites, for each satellite antenna of the plurality of satellite antennas, the observed Doppler frequency information derived by the observed Doppler frequency deriving unit, and the estimated Doppler estimated by the estimated Doppler frequency calculator A residual derivation unit that derives a residual error with the frequency information, and a plurality of satellite antennas derived from the residual error derivation unit in each of the plurality of satellites, based on the difference between the residuals of the plurality of satellite antennas. A satellite selection device including a satellite selection unit that selects a satellite to be used from the satellites.

According to a sixth aspect of the present disclosure, in the satellite selection device according to the fifth aspect, the satellite selection unit excludes satellites corresponding to the difference of the residuals equal to or more than a predetermined threshold from the satellites to be used.

A seventh aspect of the present disclosure is the satellite selection device according to the fifth aspect or the sixth aspect, further comprising a reliability determination unit that determines the reliability of each change amount of the time error of each receiver of the plurality of satellite antennas. Further, the satellite selection unit excludes from the satellites to be used based on the residual difference of each of the plurality of satellite antennas only when the reliability determination unit determines that the reliability is high. Select a satellite.

According to an eighth aspect of the present disclosure, in the satellite selection device according to the seventh aspect, the reliability determination unit includes the plurality of residuals derived by the residual derivation unit for a plurality of different predetermined satellites. If the residual error of any one of the satellite antennas is less than the threshold value of the residual error of the other satellite antennas, it is determined that the reliability of the amount of change in the time error of the receiver is high.

A ninth aspect of the present disclosure is for selecting a satellite to be used by a positioning device that calculates a position on the earth of a position to be measured in the moving body different from the installation position of a plurality of satellite antennas installed in the moving body. A program, a satellite information including information about the position of each of the plurality of satellites transmitted from each of the plurality of satellites and information about the distance between each of the plurality of satellites and the mobile body. Based on the satellite information acquired by the satellite information acquisition unit, the plurality of satellites observed at the respective installation locations of the plurality of satellite antennas, and the plurality of satellites. An observation pseudo-range deriving unit for deriving observation pseudo-range information indicating a distance to each of the satellite antennas, a predetermined positional relationship between the installation location of each of the plurality of satellite antennas and the positioning target location, and the satellite Estimating the distance between each of the plurality of satellites and each of the plurality of satellite antennas at each position from the calculated position to be measured based on the satellite information acquired by the information acquisition unit An estimated pseudo-range calculator that estimates pseudo-range information, and for each of the plurality of satellites, the observation pseudo-range information derived by the observation pseudo-range deriving unit for each satellite antenna of the plurality of satellite antennas, and the estimation A residual derivation unit that derives a residual with the estimated pseudo distance information estimated by the pseudo distance calculation unit, and a difference between the residuals of each of the plurality of satellite antennas derived by the residual derivation unit. A program for operating as a satellite selection unit that selects satellites to be excluded from the satellites to be used based on the above.

A tenth aspect of the present disclosure is to select a satellite to be used in a speed measurement device that calculates the speed of the earth on a position to be measured in the moving body different from the installation positions of a plurality of satellite antennas installed on the moving body. A program including the information about the position of each of the plurality of satellites transmitted from each of the plurality of satellites and the information about the relative speed between each of the plurality of satellites and the moving body. A satellite information acquisition unit that acquires satellite information, based on the satellite information acquired by the satellite information acquisition unit, each of the plurality of satellites observed at each installation location of the plurality of satellite antennas, and An observation Doppler frequency deriving unit that derives observation Doppler frequency information indicating relative speed between each of the plurality of satellite antennas, a speed relationship between the installation location of each of the plurality of satellite antennas and the positioning target location, and the satellite. An estimated Doppler frequency calculation unit that estimates estimated Doppler frequency information indicating the relative speed between each of the plurality of satellites and each of the plurality of satellite antennas based on the satellite information acquired by the information acquisition unit. , For each of the plurality of satellites, for each satellite antenna of the plurality of satellite antennas, the observed Doppler frequency information derived by the observed Doppler frequency deriving unit, and the estimated Doppler estimated by the estimated Doppler frequency calculator A residual derivation unit that derives a residual with frequency information, and a plurality of satellites based on the residual difference of each of the plurality of satellite antennas derived by the residual derivation unit of each of the plurality of satellites. Is a program for functioning as a satellite selection unit that selects a satellite to be used from the satellites.

The storage medium that stores the program of the present disclosure is not particularly limited, and may be a hard disk or a ROM. Further, it may be a CD-ROM, a DVD disc, a magneto-optical disc or an IC card. Furthermore, the program may be downloaded from a server or the like connected to the network.

According to the present disclosure, it is possible to obtain an effect that a satellite that can be accurately calculated can be selected when at least one of the position on the earth and the velocity of a moving body is obtained.

It is a block diagram which shows the positioning device which concerns on 1st Embodiment. It is a figure which shows the example at the time of setting two GPS antennas centering on a vehicle position as a positioning target location. It is a figure which shows the example of the attitude|position angle calculation result of the vehicle in a certain time. It is a figure for demonstrating the positional relationship calculation method of a positioning target location and an antenna installation location in an ENU coordinate system. It is a flow chart which shows the contents of the positioning processing routine in the computer of the positioning device concerning a 1st embodiment. It is a block diagram which shows the positioning device which concerns on 2nd Embodiment. It is a flowchart which shows the content of the positioning process routine in the computer of the positioning device which concerns on 2nd Embodiment. It is a block diagram which shows the speed measuring device which concerns on 3rd Embodiment. It is a figure which shows the example of the angular velocity and attitude|position angle calculation result of a vehicle in a certain time. It is a figure for demonstrating the speed relation calculation method of a positioning target location and an antenna installation location in an ENU coordinate system. It is a flow chart which shows the contents of the speed measurement processing routine in the computer of the speed measuring device concerning a 3rd embodiment. It is a block diagram which shows the speed measuring device which concerns on 4th Embodiment.

Hereinafter, embodiments that implement the technology of the present disclosure will be described in detail with reference to the drawings. Note that, in the present embodiment, a case where the technology of the present disclosure is applied to a positioning device that is mounted on a vehicle and performs positioning by acquiring GPS information transmitted from a GPS satellite will be described as an example.

<Outline of this embodiment>
When performing positioning using a plurality of GNSS antennas, the positioning target location does not match the GNSS antenna installation location where the observed value is obtained, and if the GNSS antenna installation location is affected by the multipath error, the multipath error The accuracy of the position and velocity calculated from the satellite information from the affected satellites will be less accurate than that not affected by the multipath error.

In this embodiment, satellites affected by multipath errors are excluded in advance by appropriately considering the positional relationship and speed relationship between the positioning target location and each GNSS antenna installation location, so that satellites with less error can be detected. It is possible to calculate the position and speed of the position to be measured with high accuracy using only the satellite information of.

<First Embodiment>
FIG. 1 shows an example of the configuration of the positioning device according to the first embodiment.
As shown in FIG. 1, the positioning device 10 according to the first embodiment includes a plurality of GPS antennas 12A and 12B for receiving radio waves from GPS satellites, and a plurality of GPS antennas 12A and 12B. Based on the plurality of receivers 14A and 14B that obtain the reception signals, the attitude angle sensor 16, the reception signals from the GPS satellites received by the plurality of receivers 14A and 14B, and the detection values of the attitude angle sensor 16, The satellite selecting device 18 for selecting the GPS satellite to be used and the position deriving unit 40 for executing the positioning process for estimating the position of the own vehicle are provided. The satellite selection device 18 includes a computer 30 that executes a satellite selection process that selects a GPS satellite used to derive the position of the position to be measured, and an output unit 20.

FIG. 2 shows an example of installation locations of the plurality of GPS antennas 12A and 12B.
For example, as shown in FIG. 2, the plurality of GPS antennas 12A and 12B are installed in the vehicle interior of the vehicle 50, and are installed in a position different from the position to be measured. In the present embodiment, an example will be considered in which the position to be measured is the center of the vehicle and the two GPS antennas 12A and 12B and the receivers 14A and 14B are installed at the positions shown in FIG. Here, it is assumed that the distance of each of the GPS antennas 12A and 12B from the position to be measured (vehicle center) is accurately grasped by manually measuring.

The receivers 14A and 14B are provided for the GPS antennas 12A and 12B, respectively, and the receivers 14A and 14B receive radio waves from a plurality of GPS satellites via the GPS antennas 12A and 12B and receive all of them. From the received signal from the GPS satellite, the satellite number of the GPS satellite, the orbit information (ephemeris) of the GPS satellite, the time when the GPS satellite transmitted radio waves, the strength of the received signal, the frequency, etc. are acquired as the information of the GPS satellite, and a computer is obtained. Output to 30.
The attitude angle sensor 16 is, for example, a geomagnetic sensor and detects geomagnetism.

The computer 30 in the satellite selection device 18 is configured by a CPU, a ROM that stores a program for implementing the processes described below, a RAM that temporarily stores data, and a storage device such as an HDD.

When the computer 30 is represented by functional blocks, as shown in FIG. 1, a satellite information acquisition unit 31, an antenna position/receiver time error calculation unit 32, an estimated pseudo distance calculation unit 34, a pseudo distance residual calculation unit 35, and exclusion. The satellite discriminating unit 37 is provided. The satellite information acquisition unit 31 according to the first embodiment is an example of the satellite information acquisition unit and the observation pseudo distance deriving unit of the present disclosure. The estimated pseudo distance calculation unit 34 is an example of the estimated pseudo distance derivation unit of the present disclosure. The pseudo distance residual calculation unit 35 is an example of the residual derivation unit of the present disclosure. The excluded satellite discriminating unit 37 is an example of a satellite selecting unit of the present disclosure.

The satellite information acquisition unit 31 acquires GPS satellite information for all GPS satellites that have received radio waves, and calculates and acquires GPS pseudo-range data, Doppler frequency, and position coordinates of GPS satellites. Specifically, the satellite information acquisition unit 31 acquires GPS satellite information from all of the receivers 14A and 14B for all GPS satellites that have received radio waves, and the time at which the GPS satellites transmitted radio waves and the host vehicle. The GPS pseudo distance data is calculated based on the time when the radio wave is received in. In addition, the satellite information acquisition unit 31 determines the Doppler frequency of the received signal from each GPS satellite based on the known frequency of the signal transmitted from each GPS satellite and the frequency of the received signal received from each GPS satellite. calculate. The Doppler frequency is an observation of the Doppler shift amount of the carrier frequency due to the relative speed between the GPS satellite and the vehicle. The satellite information acquisition unit 31 also calculates the position coordinates of the GPS satellites based on the orbit information of the GPS satellites and the time when the GPS satellites transmitted radio waves.

The antenna position/receiver time error calculation unit 32 obtains the positional relationship between the installation location of each of the GPS antennas 12A and 12B on the earth and the positioning target location calculated based on the attitude angle of the own vehicle, and the acquired satellite information. Based on the position of the position of the positioning target determined by using the position of each of the GPS antennas 12A and 12B, the time difference between the receivers 14A and 14B is calculated.

Specifically, the antenna position/receiver time error calculation unit 32 calculates the attitude angle of the host vehicle from the detection value of the attitude angle sensor 16 as the first step. In the present embodiment, the attitude angle of the host vehicle at that time is calculated by using the detected value of the attitude angle sensor 16 as the attitude angle of the host vehicle. In the present embodiment, the case where the attitude angle of the host vehicle is calculated using the geomagnetic sensor as the attitude angle sensor 16 has been described as an example, but the present invention is not limited to this and, for example, based on the Doppler frequency. The attitude angle of the host vehicle may be calculated using the vehicle velocity vector calculated by the above, the vehicle acceleration and the angular velocity detected by the 6-axis gyro sensor, and the like.

FIG. 3 shows an example of the attitude angle of the host vehicle 50 at a certain time. FIG. 3A shows the attitude angle of the host vehicle 50 from directly above the road surface, and FIG. 3B shows the attitude angle of the host vehicle 50 directly from the side of the road surface. Hereinafter, as shown in FIG. 3, it is assumed that the attitude angle of the host vehicle 50 at a certain time is yaw angle=θ (clockwise is positive with true north being zero), pitch angle=α, and roll angle=zero. ..

Next, as a second step, the antenna position/receiver time error calculation unit 32 determines, for each of the GPS antennas 12A and 12B, the installation location of the GPS antenna on the earth based on the calculated attitude angle of the own vehicle. , Calculate the positional relationship with the position to be measured. Specifically, first, the antenna position/receiver time error calculation unit 32 determines, in advance, the distance between the installation location of each GPS antenna 12A and 12B on the earth and the positioning target location, and each GPS. Based on the angle of the installation location of the antennas 12A and 12B and the detected attitude angle of the own vehicle, the relationship between the absolute position on the earth between the positioning target location (vehicle center) and the installation location of each GPS antenna is calculated. To do. Specifically, it is calculated by the following procedure. Note that, here, a case where the GPS antenna 12A is targeted will be described.

(Procedure 1) The positional relationship in the ENU (East-North-Up) coordinate system is calculated by the following equation (1).
FIG. 4 shows an example of the positional relationship between the position to be measured (vehicle center) and the installation location of the GPS antenna 12A. FIG. 4A shows the positional relationship seen from directly above the road surface. FIG. 4B shows the positional relationship as seen from the side of the road surface, and FIG. 4C shows the positional relationship projected on the ground surface (EN coordinate surface).

(1)

(Procedure 2) The relationship between absolute positions on the earth is calculated by converting from the ENU coordinate system to the ECEF (Earth-Centered Earth-Fixed) coordinate system using the following equation (2). Similarly, regarding the installation location of the GPS antenna 12B, the positional relationship with the positioning target location is calculated. In the following, the calculation result of the positional relationship obtained in this way will be described as “installation location of GPS antenna 12A=F _A (positioning target location)”.

(2)

here,

Further, α is the long radius [m] of the earth, and f is the oblateness.

Then, as a third step, the antenna position/receiver time error calculation unit 32 uses the calculated positional relationship and the acquired satellite information to determine the position of the position to be measured on the earth and the position of each receiver. Calculate the time difference. Specifically, the antenna position/receiver time error calculation unit 32 sets the position of the positioning target location and the time error of each of the plurality of GPS antennas 12A and 12B as unknowns, and determines the position of the positioning target location and the positioning target location. An equation describing the positions of the installation locations of the plurality of GPS antennas 12A and 12B using the relationship of the absolute position on the earth between the (vehicle center) and the respective installation locations of the antennas, and each of the plurality of GPS antennas 12A and 12B. Thus, the position of the position to be measured and the time error of each receiver are calculated based on the pseudo distances observed at the installation positions of the plurality of GPS antennas 12A and 12B. This pseudo distance is the distance between the GPS satellite and the GPS antenna based on the GPS pseudo distance data.

More specifically, the total of the three-dimensional position vector (x, y, z) in the ECEF coordinate system of the position to be measured and the time error between the two receivers 14A and 14B (hereinafter, also referred to as clock bias) is 5 in total. The number is unknown, and the three-dimensional position vectors in the ECEF coordinate system of the installation locations of the GPS antennas 12A and 12B are F _A (x, y, z) and F _B (x, y, z). Similar to (positioning by one GPS antenna), formula (3) is established for each GPS antenna 12A, 12B and each satellite (here, only the GPS antenna 12A is described. The same applies to the GPS antenna 12B. ), the position (x, y, z) of the position to be measured is calculated using the observation results of the GPS antennas 12A and 12B by a total of five or more satellites. Also, the time error of each of the receivers 14A and 14B is calculated. In addition, when the number of GPS antennas installed is N, the position (x, y, z) of the position to be positioned is calculated using the observation results of a total of (N+3) or more satellites.

...(3)

Here, the position of the GPS antenna 12A is represented by the following formula.

Further, (x, y, z) is the position of the position to be measured, and Cb _A is the clock bias [m] (converted to the distance by multiplying the speed of light) of the receiver 14A of the GPS antenna 12A. Also, PR _i is the pseudorange [m] observed for satellite i, and (X _si , Y _si , Z _si ) is the position of satellite i.

In this way, by appropriately considering the positional relationship between the positioning target location and the antenna installation location, the position of the positioning target location can be accurately measured even when using the pseudo distance observed at a position different from the positioning target location. Can be calculated.

Next, the antenna position/receiver time error calculation unit 32 uses the positional relationship between the installation location of the GPS antenna and the positioning target location and the position of the positioning target location obtained as described above as the fourth step. , The positions of the GPS antennas 12A and 12B are derived. That is, by applying the position of the positioning target location on the earth calculated in the third step to the positional relationship between the installation location of each of the GPS antennas 12A and 12B calculated in the second step and the positioning target location, The positions of the GPS antennas 12A and 12B are derived.

The estimated pseudo distance calculation unit 34 estimates, for each of the GPS antennas 12A and 12B, all of the GPS satellites that commonly receive the radio waves by the GPS antennas 12A and 12B among all the GPS satellites that have received the radio waves. A pseudo distance (hereinafter referred to as an estimated pseudo distance) is calculated. Specifically, the respective positions of the GPS antennas 12A and 12B and the respective time errors of the receivers 14A and 14B derived by the antenna position/receiver time error calculation unit 32 are substituted into the equation (3). Thus, the estimated pseudo distance is calculated for each of the GPS antennas 12A and 12B.

The pseudo-range residual calculation unit 35 calculates the difference between the observed pseudo-range (hereinafter referred to as the observed pseudo-range) and the estimated estimated pseudo-range (hereinafter referred to as the pseudo-range residual) for each of the GPS antennas 12A and 12B. That is)) is calculated. Specifically, among all the GPS satellites that have received the radio waves, for each of all the GPS satellites that commonly receive the radio waves by the GPS antennas 12A and 12B, for each of the GPS antennas 12A and 12B, using formula (4), Calculate the residual of the pseudorange.
(Residual of pseudo distance)=|(observed pseudo distance)−(estimated pseudo distance)| (4)

The excluded satellite discriminating unit 37 is used when estimating the position of the own vehicle based on the difference in the pseudo range residuals of the GPS antennas 12A and 12B of all the GPS satellites calculated by the pseudo range residual calculating unit 35. The exclusion target GPS satellites to be excluded from the GPS satellites are determined. Specifically, the excluded satellite discriminating unit 37 calculates the pseudo distance of the GPS antenna 12A calculated by the pseudo distance residual calculating unit 35 for each of all the GPS satellites commonly receiving radio waves by the GPS antennas 12A and 12B. The difference between the residual and the pseudorange residual of the GPS antenna 12B (hereinafter referred to as the pseudorange residual difference) is calculated. Then, the GPS satellite of the GPS antenna in which the absolute value of the difference in the pseudorange residual calculated for each GPS satellite is equal to or more than the threshold value is determined as the exclusion target GPS satellite to be excluded from all the GPS satellites that have commonly received radio waves. To do. In this way, the satellite affected by the multipath error can be excluded in advance by appropriately considering the positional relationship and speed relationship between the positioning target location and each GNSS antenna installation location.

The position deriving unit 40 derives the position of the position to be measured on the earth using the information of the GPS satellites. Specifically, for example, the position of the positioning target location is calculated using satellite information from GPS satellites other than the exclusion target GPS satellites. Note that the position derivation of the position to be measured by the position derivation unit 40 can be derived by, for example, the same process as the calculation by the first step to the third step in the antenna position/receiver time error calculation unit 32. Description is omitted.

As described above, by appropriately considering the positional relationship and speed relationship between the positioning target location and each GNSS antenna installation location, satellites affected by the multipath error are excluded in advance, so that satellites with less error It is possible to calculate the position and velocity of the position to be measured with high accuracy using only the satellite information from.

Next, the operation of the positioning device 10 according to the first embodiment will be described.
FIG. 5 shows an example of the contents of the satellite selection processing routine in the computer of the satellite selection device 18 in the positioning device.

When the attitude angle sensor 16 detects the geomagnetism and the GPS antennas 12A and 12B and the receivers 14A and 14B are receiving radio waves from a plurality of GPS satellites, the computer 30 of the satellite selection device 18 displays the signals as shown in FIG. The positioning processing routine shown is repeatedly executed.

In step S100, the information of a plurality of GPS satellites is acquired from the GPS receivers 14A and 14B, and the GPS pseudo range data of the plurality of GPS satellites, the Doppler frequency, and the position coordinates of the GPS satellites are calculated and acquired. GPS information for a plurality of GPS satellites acquired at the same time is acquired as a GPS information group.

Next, in step S102, the position of each installation location of the GPS antennas 12A and 12B and the time error of the receivers 14A and 14B are calculated.

Specifically, in the first step, the attitude angle of the host vehicle is calculated based on the detection value from the attitude angle sensor 16. Next, in the second step, the distance between the installation location of each GPS antenna 12A, 12B on the earth and the positioning target location, and the angle of the installation location of each GPS antenna 12A, 12B, which are obtained in advance, Based on the detected attitude angle of the host vehicle, the positional relationship in the ECEF coordinate system between the positioning target location (vehicle center) and each antenna installation location is calculated. Then, in the third stage, the position of the positioning target position and the time error of each of the receivers 14A and 14B corresponding to the plurality of GPS antennas 12A and 12B are set as unknowns, and the position of the positioning target position and the positioning target position (vehicle Using the positional relationship between the center) and each antenna installation location in the ECEF coordinate system, a plurality of equations describing the positions of the installation locations of the plurality of GPS antennas 12A and 12B and the plurality of GPS antennas 12A and 12B are used. The position of the positioning target location is calculated based on the pseudo distance observed at each installation location of the GPS antennas 12A and 12B. Also, the time error of the receivers 14A and 14B of the GPS antennas 12A and 12B is calculated. Next, in the fourth step, the position of the positioning target location on the earth calculated in the third step is calculated based on the positional relationship between the installation locations of the GPS antennas 12A and 12B calculated in the second step and the positioning target location. By applying, the positions of the GPS antennas 12A and 12B are derived.

Then, based on the GPS information group, the positions of the GPS antennas 12A and 12B, and the time difference between the receivers 14A and 14B corresponding to the GPS antennas 12A and 12B, among the commonly received GPS satellites, Set the excluded GPS satellites.

Specifically, in step S106, one of the GPS satellites (i.e., n) of all the GPS satellites (e.g., n) commonly receiving the radio waves from the GPS satellites by the plurality of GPS antennas 12A and 12B is used (i= 1) is set, and in the next step S108, each of the GPS antennas 12A and 12B is derived by using the position of each of the GPS antennas 12A and 12B derived in step S102 and the time error of each of the receivers 14A and 14B. Calculate the estimated pseudo distance of. Next, in step S110, for each of the GPS antennas 12A and 12B, the absolute value obtained by subtracting the estimated pseudo distance calculated in step S112 from the observed pseudo distance that is the observed pseudo distance is used to calculate the residual pseudo distance. Is calculated (see Formula (4)).

In the next step S112, the difference of the pseudo range residual, which is the difference between the pseudo range residual of the GPS antenna 12A calculated for the corresponding GPS satellite and the pseudo range residual of the GPS antenna 12B, is calculated. Then, in the next step S114, it is determined whether or not the absolute value of the difference between the pseudorange residuals is equal to or larger than a threshold value. It is set as an exclusion target GPS satellite to be excluded from all GPS satellites that have received the radio wave, and is output by the output unit 20. This makes it possible to exclude in advance the satellites affected by the multipath error by appropriately considering the positional relationship and speed relationship between the positioning target location and each GNSS antenna installation location.

On the other hand, if a negative determination is made in step S114, the process proceeds to step S118. In step S118, it is determined whether or not the above processing has been completed (i≧n) for all GPS satellites by determining whether or not there are remaining GPS satellites for which the above processing has not been executed. If there are GPS satellites for which the above processing has not been executed, the determination is negative in step S118, the next GPS satellite (i=i+1) is set in step S120, and the process returns to step S108. On the other hand, when the execution of the above processing is completed for all GPS satellites, the affirmative determination is made in step S118, and the process returns to step S100.

In the positioning device 10 according to the present embodiment, when the exclusion target GPS satellite is selected as described above, the position deriving unit 40 obtains the satellite information from the GPS satellites other than the selected exclusion target GPS satellite. The position of the position to be measured is calculated using this. Thus, the position on the earth is accurately calculated by excluding the GPS satellites estimated to be affected by the multipath error in advance from the positioning target position different from the installation position of the plurality of GPS antennas in the vehicle. be able to.

As described above, according to the positioning device according to the first embodiment, the satellite selection device 18 appropriately considers the positional relationship between the positioning target position and each GPS antenna installation position, and thus the influence of the multipath error. By excluding in advance the GPS satellites that are estimated to have received, it is possible to accurately calculate the position on the earth of the positioning target position in the vehicle.

Further, even if the positioning target location is not the center of gravity of each GPS antenna installation location, or even if the positioning target location and each GPS antenna installation location are distant, the position of the positioning target location is calculated with high accuracy. Is possible.

<Second Embodiment>
Next, a second embodiment will be described. Regarding the positioning device of the second embodiment, the same components as those of the positioning device 10 of the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

In the second embodiment, the first point is that the GPS satellites estimated to be affected by the multipath error are excluded in advance only when the reliability of the calculated time error of the receivers 14A and 14B is high. This embodiment is mainly different from the above embodiment.

FIG. 6 shows an example of the configuration of the positioning device according to the second embodiment.
As shown in FIG. 6, the computer 230 of the satellite selection device 218 in the positioning device 210 according to the second embodiment includes a satellite information acquisition unit 31, an antenna position/receiver time error calculation unit 32, and an estimated pseudo distance calculation unit 34. , Pseudo range residual calculation unit 35, receiver time error reliability determination unit 232, and excluded satellite determination unit 237. The receiver time error reliability determination unit 232 is an example of the reliability determination unit of the present disclosure.

The receiver time error reliability determination unit 232 determines the reliability of the time error of the receiver calculated by the antenna position/receiver time error calculation unit 32. Specifically, the reliability of the time error of the receiver may be determined according to the fluctuation of the pseudo range residual in the GPS antenna. For example, if an error occurs in the time error of the receiver, the pseudo range residuals of all GPS satellites are commonly affected. For this reason, the fact that the pseudorange residuals for all GPS satellites are larger than a certain amount indicates that there is a high possibility that the time error calculation of the receiver is erroneous, that is, the reliability is low. On the other hand, when the pseudorange residuals for all GPS satellites are less than a certain value, it is considered that there is a low possibility that the time error calculation of the receiver is erroneous, that is, the reliability is high.

More specifically, the receiver time error reliability determination unit 232 uses the pseudo distance residual calculated by the pseudo distance residual calculation unit 35 to determine whether all of the GPS antennas 12A and 12B commonly receive the same. For GPS satellites, a pseudorange residual is calculated for each GPS antenna. Next, for all GPS satellites commonly received, if the pseudorange residual of one GPS antenna is larger than the pseudorange residual of the other GPS antenna by a predetermined threshold value or more, the pseudorange residual is It is determined that the reliability of the time error of the receiver connected to the larger GPS antenna is low. This is because the error in the calculation of the time error of the receiver has a common effect on the pseudorange residuals of all the GPS satellites that are commonly received, and therefore the pseudorange residuals of all the GPS satellites are The reason why it is larger than a certain amount is that there is a high possibility that the time error calculation of the receiver is wrong. If the pseudorange residual of one GPS antenna is less than the threshold with respect to the pseudorange residual of the other GPS antenna, the reliability of the time error of the receiver connected to the GPS antenna is high. judge.

The excluded satellite discriminating unit 237, based on the reliability of the time error of the receiver determined by the receiver time error reliability determining unit 232, calculates the GPS antenna of each GPS satellite calculated by the pseudorange residual calculation unit 35. From the difference between the pseudo-range residuals of 12A and 12B, the GPS satellites to be excluded from the GPS satellites used when estimating the position of the vehicle are determined.

Specifically, when the pseudo-range residuals for all GPS satellites are less than the threshold and the receiver time error reliability determination unit 232 determines that the time error reliability of the receiver is high, Similar to the first embodiment, the exclusion target GPS satellites are determined based on the difference in the pseudo range residuals of the GPS antennas 12A and 12B of all the GPS satellites.

On the other hand, if the pseudo-range residuals for all GPS satellites are equal to or greater than the threshold value and the receiver time error reliability determination unit 232 determines that the reliability of the receiver time error is low, the exclusion target GPS satellites are used. Is not performed. For example, the GPS satellites received by any of the GPS antennas 12A and 12B are output without being excluded from the GPS satellites.

As described above, the satellite selection similar to that of the first embodiment is performed only when it is determined that the receivers of the GPS antennas 12A and 12B have high reliability of the time error. This makes it possible to exclude in advance the satellites affected by the multipath error in consideration of the reliability of the time error of the receiver determined based on the pseudorange residuals for all GPS satellites. ..

Next, the operation of the positioning device 210 according to the second embodiment will be described. In addition, about the part which becomes the same process as 1st Embodiment, the same code|symbol is attached and detailed description is abbreviate|omitted.
FIG. 7 shows an example of the contents of a satellite selection processing routine in the computer of the satellite selection device 18 as main processing in the positioning device according to the second embodiment.

While the GPS antennas 12A and 12B and the receivers 14A and 14B are receiving radio waves from a plurality of GPS satellites, the computer 230 repeatedly executes the positioning processing routine shown in FIG.

In step S100, the information of a plurality of GPS satellites is acquired from the GPS receivers 14A and 14B, and the GPS pseudo range data of the plurality of GPS satellites, the Doppler frequency, and the position coordinates of the GPS satellites are calculated and acquired. GPS information for a plurality of GPS satellites acquired at the same time is acquired as a GPS information group.

Next, in the same manner as described above, in step S102, the positions of the installation locations of the GPS antennas 12A and 12B and the time errors of the receivers 14A and 14B of the GPS antennas 12A and 12B are calculated. Then, among the GPS satellites commonly received by the GPS antennas 12A and 12B, the exclusion-targeted GPS satellites are set.

First, in step S106, one of the GPS satellites that are commonly receiving radio waves by the plurality of GPS antennas 12A and 12B is set. Then, in step S108, the estimated pseudo distance of each of the GPS antennas 12A and 12B is calculated, and in step S110, the residual pseudo distance is calculated for each of the GPS antennas 12A and 12B.

In step S200, it is determined whether or not the above processing has been completed for all GPS satellites by determining whether or not there are remaining GPS satellites that have not executed the processing for calculating the estimated pseudo distance and the residual of the pseudo distance. .. If there are GPS satellites for which the above processing has not been executed, the determination is negative in step S200, the next GPS satellite is set in step S202, and the process returns to step S200. On the other hand, when the execution of the above processing is completed for all GPS satellites, the affirmative determination is made in step S200, and the processing proceeds to step S204.

In step S204, it is determined whether or not there is a GPS antenna having a pseudo range residual of a threshold value or more among the pseudo range residuals of each GPS antenna for all GPS satellites commonly received by the GPS antennas 12A and 12B. To do. If there is a GPS antenna with a pseudorange residual of a threshold value or more, the affirmative determination is made in step S204, and the process returns to step S100 without executing the process of selecting a GPS satellite to be excluded, which will be described later. On the other hand, if all the pseudorange residuals are less than the threshold value, the determination is negative in step S204, and the process proceeds to step S206 in order to execute the process of selecting the GPS satellite to be excluded.

In step S206, one of the GPS satellites commonly receiving radio waves by the plurality of GPS antennas 12A and 12B is set. Then, in step S108, the estimated pseudo distance of each of the GPS antennas 12A and 12B is calculated, and in step S110, the residual pseudo distance is calculated for each of the GPS antennas 12A and 12B.

In the next step S208, the difference in the pseudo range residual, which is the difference between the pseudo range residual of the GPS antenna 12A and the pseudo range residual of the GPS antenna 12B, is calculated. In the next step S210, it is determined whether or not the absolute value of the difference of the pseudorange residuals is equal to or more than a threshold value. If the determination is affirmative, in step S212, the currently set GPS satellite commonly receives radio waves. It is set as an exclusion target GPS satellite to be excluded from all GPS satellites, and is output by the output unit 20. This makes it possible to exclude satellites affected by the multipath error in advance in consideration of the reliability of the time error of the receiver.

On the other hand, in the case of negative determination in step S210, the process proceeds to step S214. In step S214, it is determined whether or not the above processing has been completed for all GPS satellites by determining whether or not there are GPS satellites that have not been subjected to the above processing. If there are GPS satellites for which the above processing has not been executed, the determination is negative in step S214, the next GPS satellite is set in step S216, and then the process returns to step S208. On the other hand, when the execution of the above process is completed for all GPS satellites, the affirmative answer is obtained in step S214, and the process returns to step S100.

As described above, according to the positioning device of the second embodiment, the satellite selection device 18 determines the position to be positioned only when the reliability of the time error of the receiver connected to the GPS antenna is high. By appropriately considering the positional relationship with each GPS antenna installation location and excluding GPS satellites that are estimated to have been affected by the multipath error in advance, the position of the vehicle on the earth can be accurately determined. Can be calculated well.

<Third Embodiment>
Next, a third embodiment will be described. In the third embodiment, a case where the technology of the present disclosure is applied to a speed measurement device that calculates the speed of the host vehicle will be described as an example. In addition, about the structure same as the positioning device 10 of 1st Embodiment about the speed measuring device of 3rd Embodiment, the same code|symbol is attached|subjected and description is abbreviate|omitted.

FIG. 8 shows an example of the configuration of the speed measuring device according to the third embodiment.
As shown in FIG. 8, the velocity measuring device 310 according to the third embodiment includes a plurality of GPS antennas 12A and 12B, a plurality of receivers 14A and 14B, an attitude angle sensor 16, a gyro sensor 316, and a plurality of gyro sensors. Based on the signals received from the GPS satellites received by the receivers 14A and 14B of the GPS receiver, and the detection values of the attitude angle sensor 16 and the gyro sensor 316, the satellite selection device 318 that selects the GPS satellite to be used, and the speed of the vehicle. And a speed derivation unit 340 that executes a speed derivation process that derives The satellite selection device 318 includes a computer 330 that executes a satellite selection process that selects a GPS satellite used to derive the speed of the host vehicle, and the output unit 20.

When the computer 330 is represented by functional blocks, as shown in FIG. 8, a satellite information acquisition unit 31, an antenna speed/receiver time error change amount calculation unit 332, an estimated Doppler frequency calculation unit 334, and a Doppler frequency residual calculation. A section 335 and an excluded satellite discriminating section 337 are provided. The satellite information acquisition unit 31 according to the third embodiment is an example of the satellite information acquisition unit and the observed Doppler frequency derivation unit of the present disclosure. The estimated Doppler frequency calculation unit 334 is an example of the estimated Doppler frequency derivation unit of the present disclosure. The Doppler frequency residual calculation unit 335 is an example of the residual derivation unit of the present disclosure. The excluded satellite discriminating unit 337 is an example of a satellite selecting unit of the present disclosure.

The antenna speed/receiver time error change amount calculation unit 332 calculates the speed relationship between the installation location and the positioning target location on the earth of each of the GPS antennas 12A and 12B calculated based on the attitude angle of the own vehicle, and the acquired satellite. The speed of each of the GPS antennas 12A and 12B is calculated based on the speed of the positioning target location determined by using the information. Further, the amount of change in the time difference between the receivers 14A and 14B of the GPS antennas 12A and 12B (hereinafter referred to as clock drift) is calculated.

Specifically, the antenna speed/receiver time error change amount calculation unit 332 calculates the angular velocity of the host vehicle at that time by using the detection value of the gyro sensor 316 as the first step. Next, the antenna velocity/receiver time error change amount calculation unit 332 calculates the attitude angle of the host vehicle from the detection value of the attitude angle sensor 16 as the second step.
FIG. 9 shows an example of the attitude angle of the host vehicle 50 at a certain time. FIG. 9A shows the attitude angle of the host vehicle 50 from directly above the road surface, and FIG. 9B shows the attitude angle of the host vehicle 50 directly from the road surface. After that, as shown in FIG. 9, the angular velocity at a certain time is yaw rate=ω, pitch rate=0, roll rate=0, and the attitude angle is yaw angle=θ (clockwise is positive when true north is zero). ), pitch angle=α, and roll angle=0.

Next, the antenna velocity/receiver time error change amount calculation unit 332, as a third step, based on the calculated attitude angle of the own vehicle and the Doppler frequency of the received signal from each GPS satellite, the GPS antenna 12A, For each of the 12B, the speed relationship between the installation location of the GPS antenna on the earth and the positioning target location is calculated.
Specifically, first, the antenna speed/receiver time error change amount calculation unit 332 determines the distance between the installation location of each GPS antenna 12A, 12B on the earth and the positioning target location, which is obtained in advance, Based on the angles of the installation locations of the GPS antennas 12A and 12B and the detected attitude angles and angular velocities of the own vehicle, the speed relationship on the earth between the positioning target location (vehicle center) and each GPS antenna installation location is shown. calculate. More specifically, it is calculated by the following procedure. Note that, here, a case where the GPS antenna 12A is targeted will be described.

(Procedure 1) The velocity relationship in the ENU (East-North-Up) coordinate system is calculated by the following equation (5).
FIG. 10 shows an example of the speed relationship between the position to be measured (vehicle center) and the installation location of the GPS antenna 12A. FIG. 10(A) shows the speed relationship when viewed from directly above the road surface. 10(B) shows the speed relationship when viewed from the side directly to the road surface, and FIG. 10(C) shows the speed relationship when viewed as projected on the ground surface (EN coordinate surface).

(5)

(Procedure 2) The velocity relationship on the earth is calculated by converting from the ENU coordinate system to the ECEF (Earth-Centered Earth-Fixed) coordinate system using the following equation (6). Similarly, for the installation location of the GPS antenna 12B, the speed relationship with the location of the positioning target is calculated. In the following, the calculation results of the thus obtained speed relationship specified as "speed of installation location of the GPS antenna 12A = G _A (rate of a positioning target location)."

(6)

here,

Further, α is the long radius [m] of the earth, and f is the oblateness.

Then, as a fourth step, the antenna speed/receiver time error change amount calculation unit 332 uses the calculated speed relationship and the acquired satellite information to calculate the speed of the position to be measured on the earth and a plurality of positions. Calculate the clock drift for each receiver of the GPS antenna.
Specifically, the antenna speed/receiver time error change amount calculation unit 332 sets the speed of the positioning target location and the time error of each of the plurality of GPS antennas 12A and 12B as unknowns, and determines the speed of the positioning target location and the positioning. Using the speed relationship on the earth between the target location (vehicle center) and each antenna installation location, an equation describing the speed of the installation location of the plurality of GPS antennas 12A, 12B and each of the plurality of GPS antennas 12A, 12B According to the above, the velocity of the positioning target location and the clock drift of each receiver are calculated based on the relative velocity with the satellite obtained from the Doppler frequency observed at each installation location of the plurality of GPS antennas 12A and 12B. ..

More specifically, a total of five three-dimensional velocity vectors (Vx, Vy, Vz) in the ECEF coordinate system of the location to be positioned and a clock drift that is the amount of change in the clock bias of the two receivers 14A and 14B. Is an unknown number, and the three-dimensional velocity vector in the ECEF coordinate system of the installation location of each GPS antenna 12A, 12B is G _A (Vx, Vy, Vz) and G _B (Vx, Vy, Vz) Similar to the method (for example, speed calculation by one GPS antenna), formula (7) is established for each GPS antenna 12A, 12B and each satellite (here, only the GPS antenna 12A is described. GPS The same applies to the antenna 12B), and the velocities (Vx, Vy, Vz) of the positioning target location are calculated using the observation results of the GPS antennas 12A and 12B, which are a total of five or more satellites. An example of velocity calculation using one GPS antenna is described in Y. Kojima, "Proposal for a new localization method using tightly coupled integration based on a precise estimation of trajectory from GPS Doppler", Proceedings of AVEC2010, Laughborough UK, 2010. ). When the number of GPS antennas installed is N, the speed (Vx, Vy, Vz) and clock drift of the location to be measured are calculated using the observation results from a total of (N+3) or more satellites. ..

...(7)

Here, the speed of the GPS antenna 12A is represented by the following formula.

Further, (Vx, Vy, Vz) is the speed of the position to be measured, and Cbv _A is the clock drift [m/s] (converted to the speed by multiplying the speed of light) of the receiver 14A of the GPS antenna 12A. .. (X _A , y _A , z _A ) is the position of the GPS antenna 12A. Further, D _i is the Doppler frequency [Hz] observed for the satellite i, (X _si , Y _si , Z _si ) is the position of the satellite i, and r _i is represented by the following equation.

Further, f ₁ is the carrier frequency (1575.42×10 ⁶ ) [Hz], C is the speed of light (2.99792458×10 ⁸ ) [m/s], and (V _xsi , V _ysi , V _zsi ) is the satellite i is the speed.

In this way, by properly considering the speed relationship between the positioning target location and the antenna installation location, even if the Doppler frequency observed at a position different from the positioning target location is used, the speed of the positioning target location can be accurately measured. Can be calculated.

Next, the antenna speed/receiver time error change amount calculation unit 332 determines, as a fifth step, the speed relationship between the installation location of the GPS antenna and the positioning target location obtained as described above, and the position of the positioning target location. The respective velocities of the GPS antennas 12A and 12B are derived by using them. That is, by applying the speed of the positioning target point on the earth calculated in the fourth step to the speed relationship between the installation positions of the GPS antennas 12A and 12B and the positioning target position calculated in the third step, The speed of each of the GPS antennas 12A and 12B is derived.

The estimated Doppler frequency calculation unit 334 estimates the GPS antennas 12A and 12B for all the GPS satellites that commonly receive the radio waves among the GPS satellites that have received the radio waves. The Doppler frequency (hereinafter referred to as the estimated Doppler frequency) is calculated. Specifically, the respective speeds of the GPS antennas 12A and 12B and the clock drifts of the receivers 14A and 14B derived by the antenna speed/receiver time error change amount calculation unit 332 are substituted into the equation (7). By doing so, the estimated Doppler frequency is calculated for each of the GPS antennas 12A and 12B.

The Doppler frequency residual calculation unit 335, for each of the GPS antennas 12A and 12B, the difference between the observed Doppler frequency (hereinafter referred to as the observed Doppler frequency) and the estimated estimated Doppler frequency (hereinafter referred to as the Doppler frequency residual). .) is calculated. Specifically, among all the GPS satellites that have received the radio waves, for each of all the GPS satellites that commonly receive the radio waves with the GPS antennas 12A and 12B, for each of the GPS antennas 12A and 12B, using the formula (8), Calculate the residual of the Doppler frequency.
(Doppler frequency residual) = | (observed Doppler frequency)-(estimated Doppler frequency) |
...(8)

The excluded satellite discriminating unit 337 is used when estimating the speed of the own vehicle based on the difference between the Doppler frequency residuals of the GPS antennas 12A and 12B of all the GPS satellites calculated by the Doppler frequency residual calculating unit 335. The exclusion target GPS satellites to be excluded from the GPS satellites are determined. Specifically, the excluded satellite determination unit 337 calculates the Doppler frequency of the GPS antenna 12A calculated by the Doppler frequency residual calculation unit 335 for each of all the GPS satellites commonly receiving radio waves by the GPS antennas 12A and 12B. The difference between the residual and the Doppler frequency residual of the GPS antenna 12B (hereinafter referred to as the difference of the Doppler frequency residual) is calculated. Then, the GPS satellite of the GPS antenna whose absolute value of the difference between the Doppler frequency residuals calculated for each GPS satellite is greater than or equal to a threshold is determined as an exclusion target GPS satellite to be excluded from all the GPS satellites that have received radio waves in common. To do. In this way, the satellite affected by the multipath error can be excluded in advance by properly considering the speed relationship between the positioning target location and each GNSS antenna installation location.

The velocity deriving unit 340 derives the velocity of the positioning target location on the earth using the information of the GPS satellites. Specifically, for example, satellite information from GPS satellites other than the exclusion-targeted GPS satellites is used to calculate the speed of the positioning target location. Note that the speed of the positioning target location in the speed deriving unit 340 can be derived by, for example, the same processing as the calculation in the first to fourth steps in the antenna speed/receiver time error change amount calculating unit 332. , Detailed description is omitted.

As described above, by appropriately considering the speed relationship between the location to be positioned and each GNSS antenna installation location, satellites affected by the multipath error are excluded in advance, so that satellites from satellites with less error are It is possible to calculate the position and speed of the position to be measured with high accuracy using only the information.

Next, the operation of the speed measuring device 310 according to the third embodiment will be described.
FIG. 11 shows an example of the contents of the satellite selection processing routine in the computer of the satellite selection device 318 in the speed measurement device.

The attitude angle sensor 16 detects the geomagnetism, the gyro sensor 316 detects the angular acceleration, and the GPS antennas 12A, 12B and the receivers 14A, 14B select satellites while receiving radio waves from a plurality of GPS satellites. In the computer 330 of the device 318, the speed measurement processing routine shown in FIG. 11 is repeatedly executed.

In step S300, information on a plurality of GPS satellites is acquired from the GPS receivers 14A and 14B, and GPS pseudo range data, Doppler frequency, and position coordinates of the GPS satellites of the plurality of GPS satellites are calculated and acquired. GPS information for a plurality of GPS satellites acquired at the same time is acquired as a GPS information group.

Next, in step S302, the speed of each installation location of the GPS antennas 12A and 12B is calculated. Specifically, in the first stage, the detected value of the gyro sensor 316 is used to calculate the angular velocity of the own vehicle at the time, and in the second stage, the detected value of the posture angle sensor 16 is used to determine the attitude angle of the own vehicle. To calculate. In the next third step, for each of the GPS antennas 12A and 12B, the speed relationship between the location on the earth where the GPS antenna is installed and the location to be measured is calculated. In the next fourth step, the velocity of the location on the earth is calculated using the calculated velocity relationship and the acquired satellite information. Moreover, the clock drift of each receiver 14A, 14B of GPS antenna 12A, 12B is calculated. Then, in a fifth step, the speed of each of the GPS antennas 12A and 12B is derived using the speed relationship between the installation location of the GPS antenna and the positioning target location and the position of the positioning target location that have been obtained.

Then, based on the GPS information group, the positions of the GPS antennas 12A and 12B, and the clock drift of the receivers 14A and 14B corresponding to the GPS antennas 12A and 12B, among the commonly received GPS satellites, Set the excluded GPS satellites.

Specifically, in step S306, one of the GPS satellites (i.e., n) of all the GPS satellites (e.g., n satellites) commonly receiving the radio waves from the GPS satellites by the plurality of GPS antennas 12A and 12B is used (i=1). ) Is set, and in the next step S308, the velocity of each of the GPS antennas 12A and 12B derived in step S304 and the clock drift of each of the receivers 14A and 14B are used to determine each of the GPS antennas 12A and 12B. Calculate the estimated Doppler frequency. Next, in step S310, the residual value of the Doppler frequency is calculated by subtracting the estimated Doppler frequency calculated in step S308 from the observed Doppler frequency that is the observed Doppler frequency for each GPS antenna 12A, 12B. Is calculated (see equation (8)).

In the next step S312, the difference of the Doppler frequency residual, which is the difference between the residual of the Doppler frequency of the GPS antenna 12A calculated for the corresponding GPS satellite and the residual of the Doppler frequency of the GPS antenna 12B, is calculated. Then, in the next step S314, it is determined whether or not the absolute value of the difference between the Doppler frequency residuals is equal to or more than a threshold value. If the determination is affirmative, in step S316, the GPS satellite of the currently set GPS antenna It is set as an exclusion target GPS satellite to be excluded from all GPS satellites that have received the radio wave, and is output by the output unit 20. This makes it possible to exclude in advance the satellites affected by the multipath error by appropriately considering the positional relationship and speed relationship between the positioning target location and each GNSS antenna installation location.

On the other hand, in the case of negative determination in step S314, the process proceeds to step S318. In step S318, it is determined whether or not the above processing has been completed (i≧n) for all GPS satellites by determining whether or not the GPS satellites for which the above processing has not been executed remain. If there are remaining GPS satellites for which the above processing has not been executed, the determination is negative in step S318, the next GPS satellite (i=i+1) is set in step S320, and the process returns to step S308. On the other hand, when the execution of the above processing is completed for all the GPS satellites, the affirmative answer is obtained in step S318, and the process returns to step S300.

In the speed measurement device 310 according to the present embodiment, when the exclusion target GPS satellites are selected as described above, the speed derivation unit 340 causes the satellite information from the GPS satellites other than the selected exclusion target GPS satellites. Is used to calculate the speed of the position to be measured. Accordingly, the GPS satellite estimated to have been affected by the multipath error is excluded in advance from the positioning target position different from the position where the plurality of GPS antennas are installed in the vehicle, thereby accurately calculating the speed on the earth. be able to.

As described above, according to the speed measurement device according to the third embodiment, the satellite selection device 318 appropriately considers the speed relationship between the position to be positioned and each GPS antenna installation position to reduce the multipath error. By preliminarily excluding GPS satellites that are estimated to have been affected, it is possible to accurately calculate the speed of the earth on the position of the positioning target in the vehicle.

<Fourth Embodiment>
Next, a fourth embodiment will be described. In addition, about the speed measuring apparatus of 4th Embodiment, the same structure as the speed measuring apparatus 310 of 3rd Embodiment is attached|subjected the same code|symbol, and description is abbreviate|omitted.

In the fourth embodiment, the third embodiment is that the GPS satellites estimated to be affected by the multipath error are excluded in advance only when the calculated reliability of the clock drift of each receiver is high. The form is mainly different.

FIG. 12 shows an example of the configuration of the speed measuring device according to the fourth embodiment.
As illustrated in FIG. 12, the computer 430 of the satellite selection device 418 in the speed measurement device 410 according to the fourth embodiment includes a satellite information acquisition unit 31, an antenna speed/receiver time error change amount calculation unit 332, and an estimation. A Doppler frequency calculation unit 334, a Doppler frequency residual calculation unit 335, a receiver clock drift reliability determination unit 436, and an excluded satellite determination unit 437 are provided. The receiver clock drift reliability determination unit 436 is an example of the reliability determination unit of the present disclosure.

The receiver clock drift reliability determination unit 436 determines the reliability of the receiver clock drift calculated by the antenna speed/receiver time error change amount calculation unit 332. Specifically, the reliability of the clock drift of the receiver may be determined according to the fluctuation of the Doppler frequency residual in the GPS antenna. For example, if an error occurs in the clock drift of the receiver, it commonly affects the Doppler frequency residuals of all GPS satellites. For this reason, the fact that the Doppler frequency residuals for all GPS satellites are larger than a certain level indicates that there is a high possibility that the clock drift of the receiver is incorrectly calculated, that is, the reliability is low. On the other hand, if the residuals of the Doppler frequencies for all GPS satellites are less than a certain value, it is considered that there is little possibility that the calculation of the clock drift of the receiver is wrong, that is, the reliability is high.

More specifically, the receiver clock drift reliability determination unit 436 uses the Doppler frequency residual calculated by the Doppler frequency residual calculation unit 335 and uses the Doppler frequency residual calculated for all GPS antennas 12A and 12B in common. For GPS satellites, the residual Doppler frequency is calculated for each GPS antenna. Next, for all commonly received GPS satellites, if the residual of the Doppler frequency of one GPS antenna is larger than the residual of the Doppler frequency of the other GPS antenna by a predetermined threshold value or more, It is determined that the reliability of the clock drift of the receiver connected to the GPS antenna with the larger residual is low. This is because the calculation error of the clock drift of the receiver has a common effect on the residuals of the Doppler frequencies of all the GPS satellites that are commonly received, and thus the pseudorange residuals of all the GPS satellites. Is larger than a certain amount because it is considered that there is a high possibility that the calculation of the clock drift of the receiver is incorrect. When the residual of the Doppler frequency of one GPS antenna is less than the threshold with respect to the residual of the Doppler frequency of the other GPS antenna, the reliability of the clock drift of the receiver connected to the GPS antenna is high. Judge as high.

The excluded satellite discriminating unit 437 uses the GPS antenna of each GPS satellite calculated by the Doppler frequency residual calculating unit 335 based on the reliability of the clock drift of the receiver determined by the receiver clock drift reliability determining unit 436. From the difference between the Doppler frequency residuals of 12A and 12B, the GPS satellites to be excluded from the GPS satellites used when estimating the speed of the vehicle are determined.

Specifically, when the Doppler frequency residuals for all GPS satellites are less than the threshold value and the receiver clock drift reliability determination unit 436 determines that the reliability of the clock drift of the receiver is high, Similar to the third embodiment, the exclusion-targeted GPS satellite is determined based on the difference between the Doppler frequency residuals of the GPS antennas 12A and 12B of all the GPS satellites.

On the other hand, when the Doppler frequency residuals for all GPS satellites are equal to or greater than the threshold and the receiver clock drift reliability determination unit 436 determines that the reliability of the receiver clock drift is low, the exclusion target GPS satellites Is not performed. For example, the GPS satellites received by any of the GPS antennas 12A and 12B are output without being excluded from the GPS satellites.

As described above, the satellite selection similar to that in the third embodiment is performed only when it is determined that the reliability of the clock drift is high in both the receivers of the GPS antennas 12A and 12B. This makes it possible to exclude in advance the satellites affected by the multipath error in consideration of the reliability of the receiver clock drift determined based on the Doppler frequency residuals for all GPS satellites. ..

Note that other configurations and operations of the speed measurement device 410 according to the fourth embodiment are the same as those of the second and third embodiments, and thus description thereof will be omitted.

As described above, according to the speed measuring device according to the fourth embodiment, the speed of the positioning target point on the earth is calculated only when the reliability of the detected clock drift of the receiver of the own vehicle is high. By doing so, the speed on the earth can be stably calculated for the position to be measured.

In the above embodiment, the case where the technology of the present disclosure is applied to the positioning device or the speed measuring device mounted on the vehicle has been described as an example, but the positioning device or the speed measuring device of the present disclosure is mounted on the mobile device. The body is not limited to a vehicle. For example, the positioning device or the speed measuring device may be mounted on the robot.

Further, in the above embodiment, the case where the technology of the present disclosure is applied to the positioning device or the speed measuring device mounted on the vehicle has been described as an example, but the positioning device and the speed measuring device of the present disclosure are mounted to perform positioning. And the technique of the present disclosure may be applied when deriving the velocity.

Moreover, although the case where GPS is used as the satellite navigation system has been described as an example, other satellite positioning systems (GLONASS, BeiDou, Galileo, QZSS) may be used, or these may be used in combination.

10, 210 Positioning device 12A, 12B GPS antenna 14A, 14B Receiver 16 Attitude angle sensor 18, 218, 318, 418 Satellite selection device 20 Output unit 30, 230, 330, 340 Computer 31 Satellite information acquisition unit 32 Antenna position/reception Aircraft time error calculation unit 34 Estimated pseudo distance calculation unit 35 Pseudo distance residual calculation unit 37 Excluded satellite discrimination unit 40 Position derivation units 310 and 410 Velocity measuring device

Claims (10)

A satellite selection device for selecting a satellite to be used in a positioning device for calculating the position on the earth of a positioning target position in the moving body different from the installation positions of a plurality of satellite antennas installed in the moving body,
A satellite information acquisition unit for acquiring satellite information including information about the positions of the plurality of satellites transmitted from each of the plurality of satellites and information about a distance between each of the plurality of satellites and the moving body; ,
Based on the satellite information acquired by the satellite information acquisition unit, between each of the plurality of satellites and each of the plurality of satellite antennas observed at each installation location of the plurality of satellite antennas An observation pseudorange derivation unit that derives observation pseudorange information indicating a distance,
Based on the predetermined positional relationship between the installation location of each of the plurality of satellite antennas and the positioning target location, and the satellite information acquired by the satellite information acquisition unit, each of the plurality of satellites, An estimated pseudo distance calculation unit that estimates estimated pseudo distance information indicating the distance between each of the plurality of satellite antennas at each position from the positioning target location,
For each of the plurality of satellites, for each satellite antenna of the plurality of satellite antennas, the observation pseudorange information derived by the observation pseudorange deriving unit and the estimated pseudorange estimated by the estimated pseudorange calculation unit. A residual derivation unit for deriving a residual with information,
A satellite selecting unit that selects a satellite to be excluded from the satellites to be used, based on a difference between the residuals of each of the plurality of satellite antennas derived by the residual deriving unit;
Satellite selection device including. The satellite selection device according to claim 1, wherein the satellite selection unit excludes, from the satellites to be used, satellites corresponding to the difference of the residuals equal to or greater than a predetermined threshold. Further comprising a reliability determination unit for determining the reliability of each time error of each receiver of the plurality of satellite antennas,
The satellite selection unit selects a satellite to be excluded from the satellites to be used, based on the difference between the residuals of the plurality of satellite antennas only when the reliability determination unit determines that the reliability is high. The satellite selection device according to claim 1 or 2. The reliability determination unit is configured such that, for a plurality of predetermined number of different satellites, the residual of any one of the residuals derived by the residual deriving unit is the residual of the other satellite antennas. The satellite selection device according to claim 3, wherein it is determined that the reliability of the time error of the receiver is high when the difference is within the threshold. A satellite selection device for selecting a satellite to be used in a speed measurement device for calculating the speed of the earth at a position to be positioned in the moving body different from the installation positions of a plurality of satellite antennas installed in the moving body,
A satellite information acquisition unit that acquires satellite information including information about the position of each of the plurality of satellites transmitted from each of the plurality of satellites, and information about the relative speed between each of the plurality of satellites and the moving body. When,
Based on the satellite information acquired by the satellite information acquisition unit, between each of the plurality of satellites and each of the plurality of satellite antennas observed at each installation location of the plurality of satellite antennas An observation Doppler frequency derivation unit that derives observation Doppler frequency information indicating the relative velocity,
Each of the plurality of satellites and the plurality of satellites based on the velocity relationship between the installation location of each of the plurality of satellite antennas and the positioning target location and the satellite information acquired by the satellite information acquisition unit. An estimated Doppler frequency calculator that estimates estimated Doppler frequency information indicating the relative speed between each of the antennas,
For each of the plurality of satellites, for each satellite antenna of the plurality of satellite antennas, the observed Doppler frequency information derived by the observed Doppler frequency derivation unit, and the estimated Doppler frequency estimated by the estimated Doppler frequency calculation unit A residual derivation unit for deriving a residual with information,
A satellite selection unit that selects a satellite to be used from a plurality of satellites based on a difference between the residuals of each of the plurality of satellite antennas derived by the residual derivation unit in each of the plurality of satellites;
Satellite selection device including. The satellite selection device according to claim 5, wherein the satellite selection unit excludes satellites corresponding to the difference of the residuals equal to or more than a predetermined threshold from the satellites to be used. Further comprising a reliability determination unit that determines the reliability of each change amount of the time error of each receiver of the plurality of satellite antennas,
The satellite selection unit selects a satellite to be excluded from the satellites to be used, based on the difference between the residuals of the plurality of satellite antennas only when the reliability determination unit determines that the reliability is high. The satellite selection device according to claim 5 or 6. Among the residuals derived by the residual deriving unit for the predetermined number of different satellites, the reliability determination unit determines that the residual of any one of the plurality of satellite antennas is The satellite selection device according to claim 7, wherein it is determined that the reliability of the amount of change in the time error of the receiver is high when the residual of the satellite antenna is within a threshold value. A program for selecting a satellite to be used in a positioning device that calculates a position on the earth of a positioning target position in the moving body different from the installation positions of a plurality of satellite antennas installed in the moving body,
Computer,
A satellite information acquisition unit that acquires satellite information including information about the position of each of the plurality of satellites transmitted from each of the plurality of satellites and information about the distance between each of the plurality of satellites and the mobile body,
Based on the satellite information acquired by the satellite information acquisition unit, between each of the plurality of satellites and each of the plurality of satellite antennas observed at each installation location of the plurality of satellite antennas An observation pseudorange derivation unit that derives observation pseudorange information indicating a distance,
Based on the predetermined positional relationship between the installation location of each of the plurality of satellite antennas and the positioning target location, and the satellite information acquired by the satellite information acquisition unit, each of the plurality of satellites, An estimated pseudo distance calculation unit that estimates estimated pseudo distance information indicating a distance from each of the plurality of satellite antennas at each position from the positioning target location,
For each of the plurality of satellites, for each satellite antenna of the plurality of satellite antennas, the observation pseudorange information derived by the observation pseudorange deriving unit and the estimated pseudorange estimated by the estimated pseudorange calculation unit. A residual derivation unit that derives a residual with information, and
A satellite selection unit that selects a satellite to be excluded from the satellites to be used, based on the difference between the residuals of each of the plurality of satellite antennas derived by the residual derivation unit.
Program to function as. A program for selecting a satellite to be used in a speed measuring device that calculates the speed of the positioning target point on the earth different from the installation location of a plurality of satellite antennas installed on the mobile object,
Computer,
A satellite information acquisition unit that acquires satellite information including information about the position of each of the plurality of satellites transmitted from each of the plurality of satellites, and information about the relative speed between each of the plurality of satellites and the moving body. ,
Based on the satellite information acquired by the satellite information acquisition unit, between each of the plurality of satellites and each of the plurality of satellite antennas observed at each installation location of the plurality of satellite antennas Observation Doppler frequency derivation unit that derives observation Doppler frequency information indicating relative velocity,
Each of the plurality of satellites and the plurality of satellites based on the velocity relationship between the installation location of each of the plurality of satellite antennas and the positioning target location and the satellite information acquired by the satellite information acquisition unit. An estimated Doppler frequency calculator that estimates estimated Doppler frequency information indicating the relative speed between each of the antennas,
For each of the plurality of satellites, for each satellite antenna of the plurality of satellite antennas, the observed Doppler frequency information derived by the observed Doppler frequency derivation unit, and the estimated Doppler frequency estimated by the estimated Doppler frequency calculation unit A residual derivation unit that derives a residual with information, and
A satellite selection unit that selects a satellite to be used from a plurality of satellites based on a difference between the residuals of each of the plurality of satellite antennas derived by the residual derivation unit in each of the plurality of satellites,
Program to function as.