JP2001305210A - Position detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure a receiving position with a comparatively high accuracy by using both the GPS technique and the position detection technique of a PHS terminal in a PHS public network. SOLUTION: A GPS receiving part 12 receives a GPS signal from a GPS satellite, and a PHS receiving part 22 can communicate with a PHS base station 2. A GPS position measurement calculation part 13 finds a first probability density function regarding the measurement position by the GPS signals from three or more GPS satellites received by the GPS receiving part 12. A PHS radio wave intensity measurement part 23 finds a second probability density function regarding the measurement position based on the position of the PHS base station 2 communicating with the PHS receiving part 22 and the receiving intensity. A present position estimating part 31 determines the measurement position by finding the position where the maximum likelihood value can be obtained from the first and second probability density functions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position detecting device for measuring a receiving position by using a GPS signal from a GPS satellite and a PHS public network together.

[0002]

2. Description of the Related Art In recent years, a positioning system for measuring a receiving position by receiving satellite signals transmitted from a plurality of artificial satellites orbiting the earth has become widespread. As this type of positioning system, GPS (Global Positioning S
ystem) is widely known. In a receiving device used for GPS, as shown in FIG. 8, a GPS antenna 11 transmits a GPS signal from an artificial satellite (hereinafter, referred to as a “GPS satellite”).
The GPS signal is received by the GPS receiving unit 12, and the GPS satellite that transmitted the GPS signal is identified by demodulating the navigation data (navigation message). The receiver simultaneously receives GPS signals from three or more (generally four or more) GPS satellites,
The output from the PS receiving unit 12 is input to a positioning operation processing unit 13 ′. In the positioning operation processing unit 13 ′, the position information and time information of each GPS satellite obtained from the navigation message and the GPS signal of each GPS satellite are output. A pseudo distance and a Doppler shift to each GPS satellite are calculated based on a time difference between the transmission time and the reception time (arrival time data) and the reception frequency, and an error between these and a clock signal in the receiving device (that is, each pseudo time). The receiving position is determined two-dimensionally or three-dimensionally, including a clock bias which is an error equally included in the distance. The determined position thus obtained is output through the current position output unit 6.

[0003] It is known that the magnitude of the positioning error varies depending on the geometrical arrangement of the GPS satellite receiving the GPS signal in the receiving device. Also, GPS
Since the signal contains the accuracy degradation signal, if positioning is performed using only the GPS signal, an error of about 100 m will be included. In addition, in order to determine a receiving position by the GPS technology, it is necessary to simultaneously receive GPS signals from three or more GPS satellites. However, in an urban area, a GPS signal is blocked by a building or an overpass, and three or more GPS signals are received. The condition that GPS signals from satellites are received simultaneously may not be satisfied.

On the other hand, in the PHS public network, a technique for determining the position of a PHS terminal is used. In this technique, the ID number (CS-ID) of a PHS base station communicating with the PHS terminal whose position is to be specified is used. ) To the center station, it is possible for the PHS base station to obtain position information with an accuracy within a range that allows communication with the PHS terminal. If a PHS terminal whose position is to be specified can communicate with a plurality of PHS base stations, the PHS terminal
It can be determined that the PHS terminal exists within the range surrounded by the PHS base stations that can communicate with the terminal. For example, if there are two PHS base stations that can communicate with the PHS terminal, the circle connecting both PHS base stations is within a circle whose diameter is three. Within a triangle with the station at the top.

[0005]

As described above, the technique for determining the position of the PHS terminal is such that the accuracy of the position of the PHS base station can be obtained only within the range in which communication with the PHS terminal is possible. And usually 100 to 500
It includes an error of about m. In addition, the accuracy of position measurement by GPS can be determined with an accuracy of about 100 m when GPS signals from three or more GPS satellites can be received at the same time. In many cases, GPS signals from GPS satellites cannot be received at the same time.

The present invention has been made in view of the above circumstances, and an object of the present invention is to determine a reception position with relatively high accuracy by using both GPS technology and PHS terminal position detection technology in a PHS public network. It is an object of the present invention to provide a position detecting device which makes it possible to perform the position detection.

[0007]

According to the first aspect of the present invention, there is provided a communication system comprising:
A GPS receiver for receiving a GPS signal from the S satellite,
The likelihood is maximized from the PHS receiving unit capable of communicating with the HS base station, the pseudo distance to the GPS satellite obtained from the GPS signal received by the GPS receiving unit, and the position of the PHS base station obtained through the PHS receiving unit. And a positioning operation processing unit for obtaining a positioning position. According to this configuration, G
Since not only the position information obtained from the GPS signal from the PS satellite but also the position information obtained by communication with the PHS base station is used, when the position can be detected only by the GPS signal, the positioning position is obtained with higher accuracy. It becomes possible. Further, even when the position cannot be detected only by the GPS signal, it may be possible to obtain the positioning position by adding the position information obtained by the communication with the PHS base station. For example, even when a GPS signal can be obtained from only two GPS satellites in an urban area or the like, if communication with a PHS base station is possible, three or more fixed-point position information can be obtained. The positioning position can be specified two-dimensionally. That is, the possibility of positioning can be increased. On the other hand, in a suburb where the number of PHS base stations is small, there is a high possibility that GPS signals from three or more GPS satellites can be received. Therefore, positioning can be performed using only GPS signals. In this manner, the positioning position can be specified regardless of the city area and the suburbs.

According to a second aspect of the present invention, in the first aspect of the present invention, the positioning operation processing section receives the 3D signal received by the GPS receiving section.
A GPS positioning calculation unit for obtaining a first probability density function for a positioning position from GPS signals from more than one GPS satellites, and a positioning position based on the position and reception strength of the PHS base station with which the PHS receiving unit is communicating. A PHS radio field intensity measurement unit for obtaining a second probability density function;
And a current position estimating unit for determining a position at which the maximum likelihood value can be obtained from the probability density function described above and using the obtained position as a positioning position. According to this configuration, when the positioning position can be specified only by the GPS signal from the GPS satellite, the positioning accuracy can be improved by adding the position information obtained by the communication with the PHS base station.

According to a third aspect of the present invention, in the first aspect of the present invention, the positioning operation processing section obtains a pseudo distance to each of the GPS satellites based on GPS signals from a plurality of GPS satellites received by a GPS receiving section. Pseudo-distance measuring unit and P
A PHS radio field intensity measurement unit for obtaining a distance to a PHS base station at a known position based on the position and reception intensity of the PHS base station with which the HS reception unit is communicating, and an unknown number of the latitude and longitude and the clock bias of the positioning position And the positioning position and each G
The pseudo distance to the PS satellite and the distance to the PHS base station, and each GPS satellite and P for the estimated positioning position
A least-squares convergence calculation positioning position calculation unit for obtaining a clock position and a latitude and longitude of a positioning position, which are unknown, as a least-squares estimator of a nonlinear simultaneous equation obtained from the direction cosine vector of the HS base station. is there. According to this configuration, even when the positioning position cannot be specified only by the GPS signal from the GPS satellite, the positioning position can be specified by adding the position information obtained by communicating with the PHS base station. . That is, even in a case where only GPS signals from two GPS satellites can be received in an urban area or the like, if communication with the PHS base station is possible, it is possible to obtain a positioning position.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the first weighting section multiplies a weighting factor equal to the pseudo distance to each GPS satellite obtained by the pseudo distance measuring section,
A second weighting unit is provided for multiplying the distance to the PHS base station obtained by the HS radio field intensity measurement unit by a weighting factor, and the weighted value is provided to the least square convergence calculation positioning position calculation unit. According to this configuration, the GPS from the GPS satellite
The difference in accuracy between the pseudorange obtained from the signal and the distance to the PHS base station obtained by communication with the PHS base station can be reduced by weighting, and more reliable positioning can be performed.

According to a fifth aspect of the present invention, in the third aspect of the present invention, a first weighting section for individually multiplying the pseudo distance to each GPS satellite obtained by the pseudo distance measuring section by a weighting factor, A second weighting unit for multiplying the distance to the PHS base station obtained by the strength measuring unit by a weighting coefficient;
The weighted value is given to the least squares convergence calculation positioning position calculation unit. According to this configuration, the difference in accuracy between the pseudorange obtained from the GPS signal from the GPS satellite and the distance to the PHS base station obtained by communication with the PHS base station can be reduced by weighting. Also, since the difference in the accuracy of the pseudo distance different for each GPS satellite can be reduced by weighting, more reliable positioning can be performed.

According to a sixth aspect of the present invention, in the first aspect of the present invention, the positioning operation processing section obtains a pseudo distance to each GPS satellite based on GPS signals from a plurality of GPS satellites received by the GPS receiving section. Pseudo-distance measuring unit and P
A PHS radio wave intensity measurement unit for obtaining a distance to a PHS base station at a known position based on the position of the PHS base station with which the HS receiving unit is communicating and the reception intensity, and a pseudo distance and a PHS radio wave obtained by the pseudo distance measurement unit The Kalman filter takes into account the dynamic characteristics of a moving object equipped with a GPS antenna for receiving a GPS signal and a PHS antenna for communicating with the PHS base station at the distance to the PHS base station determined by the strength measuring unit. And a Kalman filter positioning position calculation unit for obtaining a clock bias. According to this configuration, when the positioning position can be specified only by the GPS signal from the GPS satellite, the positioning accuracy can be improved by adding the position information obtained by the communication with the PHS base station. In addition, accurate positioning can be performed even when the positioning position is mounted on the moving body and changes every moment.

[0013] According to a seventh aspect of the present invention, in the sixth aspect of the present invention, the initial estimated value of the positioning position used in the Kalman filter positioning position calculating section is set as the position of the PHS base station with which the PHS receiving section is communicating. . According to this configuration, it is possible to perform accurate positioning in a short time from the start without a large deviation of the initial estimated value.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) In the present embodiment, when the positioning of the reception position is possible only with the GPS technology, that is, three or more (when three-dimensional positioning is performed, four reception positions are required).
An example is shown in which it is assumed that GPS signals from (or more than) GPS satellites can be received at the same time, and the positioning accuracy is improved by using a technique for specifying the position of the PHS terminal together.

That is, in the GPS technology, it is known that the magnitude of the positioning error changes depending on the geometrical arrangement of the GPS satellite receiving the GPS signal in the receiving device. It is known that this type of positioning error increases as the variation in the distance from the receiving device to the GPS satellite increases, and that the error distribution is elliptical on a horizontal plane. This is derived from the mathematical property of a matrix (referred to as an observation matrix) having the direction of each GPS satellite as a component viewed from the receiving device, and an ellipse in which the error is distributed is called an error ellipse (see FIG. 2, the error ellipse). E1 is exemplified). That is, the positioning error is large in the major axis direction of the ellipse, and small in the minor axis direction of the ellipse. Further, the center of the error ellipse E1 can be the position P1 obtained from the GPS signal.

On the other hand, in the positioning using the PHS technology, as described as the conventional configuration, the positioning can be performed with an accuracy of about the communication range between the PHS base station and the PHS terminal, and the radio wave from the PHS base station can be obtained. Is known, so P
By taking into account the electric field strength of the radio wave received by the HS terminal, the range in which the PHS terminal exists can be narrowed. Here, the communication range between the PHS base station and the PHS terminal is approximated by a circle centered on the PHS base station. Actually, the communication range does not become circular due to the influence of buildings and the like, but it can be said that this is a relatively good model as an approximate model. That is, taking into account the reception strength (electric field strength of radio waves) at the PHS terminal, the range in which the PHS terminal is estimated to be present becomes an annular range. For example, in FIG.
When the position of the HS base station is P2 and the communication range with the PHS terminal is D2, the existence range of the PHS terminal obtained from the electric field strength can be estimated as an annular range represented by E2.

From the above, if the receiving device for receiving the GPS signal and the PHS terminal are located at the same position, and the error ellipse E1 and the range E2 of the PHS terminal are represented as shown in FIG. It can be said that there is a high possibility that the position to be obtained is included in a range where the error ellipse E1 and the existence range E2 overlap. Here, it is possible to set a probability density function using the position as a variable in the error ellipse E1 and the existence range E2. Therefore, if the position having the highest existence probability in the overlapping range of both is obtained, the accuracy is good. The position can be determined. That is, as shown in FIG. 3, the position of the receiving device estimated by the GPS technology (that is, the positioning position)
, The probability distribution function relating to the probability that the receiving device is present is PD1, and the PHS terminal exists at the position of the PHS terminal obtained from the reception intensity at the PHS terminal when the position of the PHS base station is P1. Assuming that the probability distribution function relating to the probability is PD2, both probability distribution functions PD1,
The position P0 at which the position at which the maximum likelihood value is obtained from PD2 can be determined.

Hereinafter, an apparatus for realizing the above-described principle will be described. As shown in FIG. 1, the position detecting device 1 according to the present embodiment has functions of a GPS receiving device and a PHS terminal. That is, the position detecting device 1
Is a GPS antenna 11 for receiving a GPS signal,
A GPS receiver 12 for demodulating navigation data from the S signal and obtaining a reception frequency, a PHS antenna 21 for receiving a radio wave from the PHS base station 2, and a PHS for demodulating position data from a signal received from the PHS base station. And a receiving unit 22. The PHS receiver 22 is configured to handle not only downlink signals but also uplink signals with the PHS base station 2. The output of the GPS receiver 12 is G
The received position is input to the PS positioning operation unit 13 to measure the position. However, this reception position is represented as an error ellipse E1 (that is, a probability density function PD1).

On the other hand, the PHS base station 2 is connected to a center station 4 via a public network 3. In the PHS receiver 22, P
When communication with the HS base station 2 is possible, the identification number (CS-ID) of the PHS base station 2 can be known. In the center station 4, the CS-ID of each PHS base station 2 and
The installation location and the database are stored. Therefore, the PHS receiver 22 connects to the center station 4 and
By transmitting the CS-ID learned through the communication with the HS base station 2 to the center station 4, the position information of the PHS base station 2 is received from the center station 4 through the public network 3. PHS
The position information of the base station 2 is data indicating latitude and longitude, and if the position information of the PHS base station 2 is known, the reception position of the PHS receiving unit 22 can be roughly known. Furthermore, PH
The S receiving unit 22 converts the received signal from the PHS base station 2 into a PH signal.
The electric field strength of the radio wave input to the S radio wave intensity measuring unit 23 and received from the PHS base station 2 is measured by the PHS radio wave intensity measuring unit 23. Here, since the output power of the radio wave from each PHS base station 2 is known, by applying it to the attenuation characteristic with respect to the distance of the radio wave radiated in the three-dimensional space,
The electric field intensity measured by the PHS radio wave intensity
It can be converted into a distance from the base station 2. That is, the above-described annular existence range E2 (that is, the probability density function PD2) can be obtained. However, in a city area or the like, since a radio wave is reflected by a building or the like, the annular existence range E2 cannot be set accurately.
In a simplified manner, the position of the PHS receiver 22 is estimated with relatively good accuracy by setting an annular existence range E2 in which the electric field strength of the received radio wave is converted into the distance with the position of the PHS base station 2 as the center. It is possible to Here, it is assumed that the position detecting device exists on the ground.

The above-described GPS positioning calculation unit 13 and PHS radio field intensity measurement unit 23 constitute a positioning calculation processing unit 5 together with the current position estimation unit 31. The GPS positioning calculation unit 13 and the PHS radio field intensity measurement unit 23 The obtained probability density functions PD1 and PD2 are input to the current position estimating unit 31, and the current position estimating unit 31 outputs two probability density functions P
The maximum likelihood value of the existence probability of the reception position is obtained from D1 and PD2,
The position at which the maximum likelihood value is obtained is output through the current position output unit 6. That is, when compared with the case where the positioning position is obtained based only on the range of the error ellipse E1 obtained from the GPS technology or the case where the positioning position is obtained only based on the existence range E2 obtained from the PHS technology, the positioning position is obtained with high reliability. Can be requested.

(Second Embodiment) In this embodiment, the PHS technology is used together when only GPS signals from a smaller number of GPS satellites than those required for positioning can be received. This enables positioning. For example, in order to perform three-dimensional positioning, it is necessary to simultaneously receive GPS signals from four or more GPS satellites, but if only GPS signals from three or less GPS satellites can be received, two-dimensional positioning is required. You can only determine the location. GPs from two or less GPS satellites
If only S signals can be received, two-dimensional positioning cannot be performed only by using the GPS technology.

In the following, a case where two-dimensional positioning is to be performed will be described assuming a case where only GPS signals from two GPS satellites can be received. As shown in FIG.
In the present embodiment, a pseudo distance measuring unit 14 is provided in place of the GPS positioning calculating unit 12 in the first embodiment, and a least square convergence calculating positioning position calculating unit 32 is provided in place of the current position estimating unit 31. . Least-squares convergence calculation positioning position calculation unit 3
The processing in 2 will be described later.

First, a process based on a GPS signal from a GPS satellite will be described. The GPS signal is received by the GPS antenna 11 and input to the GPS receiving unit 12, and the navigation message and the like demodulated by the GPS receiving unit 12 are input to the pseudo distance measuring unit 14. In the pseudo distance measuring unit 14, each GP
A pseudo distance to the S satellite is obtained. However, the obtained pseudo distance includes the clock bias of the GPS receiver 22.

On the other hand, in the PHS receiving section 22, the PHS received by the PHS antenna 21 is transmitted as in the first embodiment.
A received signal corresponding to a radio wave from the HS base station 2 is input to the PHS radio wave intensity measurement unit 23. Therefore, the PHS radio wave intensity measuring unit 23 converts the electric field intensity of the received signal into a distance. Further, the PHS receiving section 22 can obtain the position information of the PHS base station 2 by making an inquiry to the center station 4.

When the pseudo distance to the two GPS satellites and the distance to the PHS base station (estimated distance) are obtained as described above, the latitude Lat and longitude Lon of the positioning position and the GP
For the three unknowns with the clock bias T of the S receiving unit 22, the simultaneous equations shown in Equation 1 can be set.

[0026]

(Equation 1)

In Equation 1, GPS_pr1 and GP_pr1
S_pr2 is the two GPS values obtained by the pseudo distance measuring unit 14
Each pseudo distance to the satellite, PHS_r, is an estimated distance to the PHS base station 2 obtained by the PHS radio field intensity measurement unit 23. H11, H12, H21, H22, H
Reference numerals 31 and H32 denote direction cosine of an azimuth determined by a geometrical positional relationship between the position detection device 1 and each GPS satellite and the PHS base station 2. The above calculation is repeated, and the direction cosine is obtained from the difference between the estimated previous reception position and the current satellite position. GPS
Techniques for obtaining a direction cosine matrix are well known in the art, and the direction cosine for the PHS base station 2 can be similarly calculated. Δ in Equation 1 means a difference from the previous value.

Since the simultaneous equations shown in Equation 1 are nonlinear simultaneous equations and cannot uniquely determine a solution, by performing a least-squares convergence operation (that is, by obtaining ΔX as a least-squares estimator), A maximum likelihood estimation value of the latitude and longitude of the positioning position, which is an unknown number, and the clock bias is obtained. This calculation is a least-squares convergence calculation positioning position calculation unit 3
Perform in 2. The determined positioning position is output through the current position output unit 6. Other configurations and operations are the same as those of the first embodiment.

(Third Embodiment) In this embodiment, two-dimensional positioning is performed, as in the first embodiment, in the case where GPS signals from three GPS satellites can be received. An example in which a measured position can be obtained with higher accuracy than in the first embodiment will be described. In the present embodiment, the positioning position obtained by using the GPS technology and P
The difference in reliability from the measured position obtained by using the HS technique is taken into consideration. That is, as described in the first and second embodiments, GPS technology and P
Since the positioning position obtained in combination with the HS technology is stochastically obtained as the maximum likelihood value, if values having different reliability are used in combination with the same weight, the accuracy of the positioning position may be reduced.

Therefore, in the present embodiment, the information obtained by the GPS technology and the information obtained by the PHS technology are respectively weighted in the form of Equation 2, and the weighted values are used. The positioning position as the maximum likelihood value is obtained.

[0031]

(Equation 2)

Where w_g is each GPS
The inverse of the estimated error variance of the pseudorange to the satellite, w_
phs is the reciprocal of the estimated error variance of the estimated distance to the PHS base station 2.

That is, as shown in FIG. 5, the positioning operation processing section 5 is provided with a pseudo distance measuring section 14 and a PHS radio field intensity measuring section 23 which are the same as those in the second embodiment, and each of the positioning arithmetic processing section 5 extends to each GPS satellite. The pseudo distance and the estimated distance to the PHS base station 2 are obtained. If the least-squares convergence calculation is applied to the pseudo distance and the estimated distance obtained in this way, the measured position can be obtained as the maximum likelihood value. In the present embodiment, the measured position is calculated from the pseudo distance and the estimated distance. Rather than directly obtaining the weights, weighting units 15 and 25 are provided for multiplying the pseudo distance and the estimated distance by appropriate weighting factors, respectively, and the values after weighting are subjected to least square convergence calculation. It is. Therefore, in the present embodiment, the least-squares convergence calculation positioning position calculation unit 33 for performing the least-squares convergence calculation on the outputs of the weighting units 15 and 25 to obtain the positioning position is provided. The positioning position obtained by the position calculation unit 33 is output through the current position output unit 6. Other configurations and operations are the same as those of the first embodiment.

(Fourth Embodiment) In the third embodiment, the pseudo weight to each GPS satellite is multiplied by the same weighting factor w_g. Different weighting factors w_g for pseudo distances
By multiplying by 1, w_g2, w_g3, it is possible to obtain the positioning position with higher accuracy. Each GP
The weight coefficient obtained for the S satellite is set based on the reliability according to the reception strength of each GPS signal. That is,
The weight coefficients w_g1, w_g2, and w_g3 are set assuming that the larger the C / N (carrier noise ratio) included in the received GPS signal, the smaller the error variance.

[0035]

(Equation 3)

[Mathematical formula-see original document] In Equation 3, w_g1, w_g
2, w_g3 is the reciprocal of the estimated error variance of the pseudorange to each GPS satellite, and w_phs is the reciprocal of the estimated error variance of the estimated distance to the PHS base station 2.

The present embodiment is different from the third embodiment shown in FIG. 5 only in that the weighting section 15 multiplies the weight coefficient set for each pseudo distance by the weighting section 15. The operation is similar to that of the third embodiment.

(Fifth Embodiment) This embodiment shows an example of a configuration suitable for a case where the measured position changes every moment, that is, for performing positioning with a moving body. Here, the current position estimating unit 31 in the first embodiment is considered in consideration of the dynamic characteristics of the moving body.
Instead, a Kalman filter positioning position calculation unit 34 is used as shown in FIG. Kalman filter positioning position calculation unit 34
Is for obtaining a positioning position using a Kalman filter, and is configured to perform the arithmetic processing shown in Expression 4. Further, a moving body dynamics parameter storage unit 35 is provided to provide the dynamic characteristics of the moving body to the Kalman filter. Here, as for the observation value, the reliability of the observation value according to the reception intensity is taken into consideration, as in the fourth embodiment. Other configurations and operations are the same as those of the first embodiment.

[0039]

(Equation 4)

(Sixth Embodiment) This embodiment relates to a fifth embodiment.
A Kalman filter positioning position calculation unit 34 is provided similarly to the embodiment. However, as shown in FIG.
An initial estimated value input unit 36 is provided to give the position information of the PHS base station 2 output from the S receiving unit 22 as an initial estimated value of the Kalman filter.

In general, when positioning is performed using a pseudorange obtained based on a GPS signal from a GPS satellite, if the initial estimated value of the Kalman filter is set to a position that is significantly different from the true position, the GPS satellite will Under the condition that the positional relationship causes a large error, the sudden measurement noise different from the normally distributed normal noise causes the position to be located far away from the true position. May occur rarely and may contribute to error degradation.

In this embodiment, the Kalman filter positioning position calculation unit 34 uses PH as an initial estimated value of the positioning position.
By using the position of the S base station 2, the positioning position (positioning solution) obtained by the Kalman filter positioning position calculation unit 34
However, when a positioning solution that is far away from the position of the PHS base station 2 input as the initial estimated value and is apparently considered to be out of the reception area is obtained, it can be determined that the data is abnormal. Can be eliminated. Other configurations and operations are the same as those of the fifth embodiment.

In each of the above embodiments, the PH
Although the example in which only the position information obtained from one PHS base station 2 is used in the S receiving unit 22 has been described, a plurality of PHS
If communication with the base station 2 is possible, they may be used together, and the same processing procedure can be used to more accurately specify the positioning position.

[0044]

According to the first aspect of the present invention, G is transmitted from a GPS satellite.
A GPS receiver for receiving a PS signal, a PHS receiver capable of communicating with a PHS base station, a pseudo-range to a GPS satellite obtained from a GPS signal received by the GPS receiver, and P
A positioning operation processing unit for obtaining a positioning position at which the likelihood is maximized from the position of the PHS base station obtained through the HS receiving unit, and not only the position information obtained from the GPS signal from the GPS satellite but also the PHS base station. Since the position information obtained by communication with the station is also used, when the position can be detected only by the GPS signal, the positioning position can be obtained with higher accuracy. Further, even when the position cannot be detected only by the GPS signal, it may be possible to obtain the positioning position by adding the position information obtained by the communication with the PHS base station. For example, even when a GPS signal can be obtained from only two GPS satellites in an urban area or the like, if communication with a PHS base station is possible, three or more fixed-point position information can be obtained. Position 2
It can be specified dimensionally. That is, the possibility of positioning can be increased. On the other hand, in suburban areas where the number of PHS base stations is small, GPS from three or more GPS satellites is used.
Since there is a high possibility that a signal can be received, positioning can be performed using only a GPS signal. In this manner, the positioning position can be specified regardless of the city area and the suburbs.

According to a second aspect of the present invention, in the first aspect of the present invention, the positioning operation processing section receives the three-dimensional signal received by the GPS receiving section.
A GPS positioning calculation unit for obtaining a first probability density function for a positioning position from GPS signals from more than one GPS satellites, and a positioning position based on the position and reception strength of the PHS base station with which the PHS receiving unit is communicating. A PHS radio field intensity measurement unit for obtaining a second probability density function;
And a current position estimating unit that determines a position at which the maximum likelihood value is obtained from the probability density function of
When the positioning position can be specified only by the GPS signal from the S satellite, the positioning accuracy can be improved by taking into account the position information obtained by communication with the PHS base station.

According to a third aspect of the present invention, in the first aspect of the present invention, the positioning operation processing section calculates a pseudo distance to each of the GPS satellites based on GPS signals from a plurality of GPS satellites received by the GPS receiving section. Pseudo-distance measuring unit and P
A PHS radio field intensity measurement unit for obtaining a distance to a PHS base station at a known position based on the position and reception intensity of the PHS base station with which the HS reception unit is communicating, and an unknown number of the latitude and longitude and the clock bias of the positioning position And the positioning position and each G
The pseudo distance to the PS satellite and the distance to the PHS base station, and each GPS satellite and P for the estimated positioning position
A least-squares convergence calculation positioning position calculation unit for obtaining a clock position and a latitude and longitude of a positioning position, which are unknown, as a least-squares estimator of a nonlinear simultaneous equation obtained from the direction cosine vector of the HS base station. Yes, GPS
Even when the positioning position cannot be specified only by the GPS signal from the satellite, the positioning position can be specified by adding the position information obtained by communicating with the PHS base station. In other words, two GPSs in an urban area, etc.
Even when only GPS signals from satellites can be received, if communication with the PHS base station is possible, it is possible to obtain a positioning position.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the first weighting section multiplies a weighting coefficient equal to the pseudo distance to each GPS satellite obtained by the pseudo distance measuring section,
A second weighting unit that multiplies the distance to the PHS base station obtained by the HS radio field intensity measurement unit by a weighting coefficient, and provides the weighted value to the least square convergence calculation positioning position calculation unit; PHS obtained by communication with a PHS base station and a pseudorange obtained from a GPS signal from a GPS satellite
The difference in accuracy from the distance to the base station can be reduced by weighting, and more reliable positioning is possible.

According to a fifth aspect of the present invention, in the third aspect of the present invention, a first weighting unit for individually multiplying the pseudo distance to each GPS satellite obtained by the pseudo distance measuring unit by a weighting factor, A second weighting unit for multiplying the distance to the PHS base station obtained by the strength measuring unit by a weighting coefficient;
The weighted value is given to the least-squares convergence calculation positioning position calculation unit, and the pseudo-range obtained from the GPS signal from the GPS satellite and the distance to the PHS base station obtained by communication with the PHS base station are calculated. Not only the difference in accuracy can be reduced by weighting, but also the difference in accuracy of pseudoranges different for each GPS satellite can be reduced by weighting, so that more reliable positioning is possible. .

According to a sixth aspect of the present invention, in the first aspect of the present invention, the positioning operation processing section calculates a pseudo distance to each GPS satellite from the GPS signals received by the GPS receiving section from a plurality of GPS satellites. Pseudo-distance measuring unit and P
A PHS radio wave intensity measurement unit for obtaining a distance to a PHS base station at a known position based on the position of the PHS base station with which the HS receiving unit is communicating and the reception intensity, and a pseudo distance and a PHS radio wave obtained by the pseudo distance measurement unit The Kalman filter takes into account the dynamic characteristics of a moving object equipped with a GPS antenna for receiving a GPS signal and a PHS antenna for communicating with the PHS base station at the distance to the PHS base station determined by the strength measuring unit. And a Kalman filter positioning position calculation unit for obtaining a clock bias. When a positioning position can be specified only by a GPS signal from a GPS satellite, positioning is performed by taking into account position information obtained by communication with a PHS base station. Accuracy can be improved. In addition, accurate positioning can be performed even when the positioning position is mounted on the moving body and changes every moment.

According to a seventh aspect of the present invention, in the sixth aspect of the present invention, the initial estimated value of the positioning position used in the Kalman filter positioning position calculating section is set to the position of the PHS base station with which the PHS receiving section is communicating. In addition, the initial estimated value is not largely shifted, and accurate positioning can be performed in a short time from the start.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram illustrating the principle of the above.

FIG. 3 is an operation explanatory view of the above.

FIG. 4 is a block diagram showing a second embodiment of the present invention.

FIG. 5 is a block diagram showing a third embodiment of the present invention.

FIG. 6 is a block diagram showing a fifth embodiment of the present invention.

FIG. 7 is a block diagram showing a sixth embodiment of the present invention.

FIG. 8 is a block diagram showing a conventional example.

[Explanation of symbols]

 Reference Signs List 1 position detecting device 2 PHS base station 3 public network 4 center station 5 positioning calculation processing unit 6 current position output unit 11 GPS antenna 12 GPS reception unit 13 GPS positioning calculation unit 14 pseudo distance measurement unit 15 weighting unit 21 PHS antenna 22 PHS Receiving unit 23 PHS radio wave intensity measuring unit 25 Weighting unit 31 Current position estimating unit 32 Least square convergence calculation positioning position calculation unit 33 Least square convergence calculation positioning position calculation unit 34 Kalman filter positioning position calculation unit 35 Mobile dynamics parameter storage unit 36 Initial estimation value input section

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takuya Sueto 1048 Kadoma Kadoma, Osaka Pref.Matsushita Electric Works, Ltd. 72) Inventor Ikuo Tsujimoto 1048 Kadoma, Kadoma, Osaka Prefecture Inside Matsushita Electric Works Co., Ltd. 1048 Kadoma Kadoma Kadoma Matsushita Electric Works Co., Ltd.F-term (reference) FF03 FF16 HH07 JJ52 JJ54 JJ56 JJ64 KK01 9A001 CC05 JJ78

Claims (7)

[Claims] 1. A PHS capable of communicating with a GPS receiver for receiving a GPS signal from a GPS satellite and a PHS base station.
A receiving unit; a positioning operation processing unit for obtaining a positioning position at which the likelihood is maximized from a pseudo distance to a GPS satellite obtained from a GPS signal received by the GPS receiving unit and a position of the PHS base station obtained through the PHS receiving unit; A position detecting device comprising: 2. The positioning calculation processing section comprising: a GPS positioning calculation section for obtaining a first probability density function relating to a positioning position based on GPS signals from three or more GPS satellites received by a GPS reception section; and a PHS reception section. A PHS radio field intensity measurement unit that obtains a second probability density function for the positioning position based on the position of the communicating PHS base station and the reception intensity; and a maximum likelihood value is obtained from the first and second probability density functions. 2. The position detecting device according to claim 1, further comprising: a current position estimating unit that obtains a position and sets it as a positioning position. 3. The PHS receiving unit communicates with the PHS receiving unit, wherein the positioning operation processing unit determines a pseudo distance to each of the GPS satellites based on GPS signals from a plurality of GPS satellites received by the GPS receiving unit. A PHS radio field intensity measurement unit that calculates the distance to the PHS base station at a known position based on the position of the PHS base station and the reception intensity, and the latitude and longitude of the positioning position and the clock bias as unknowns, and Positioning that is unknown as a least-squares estimator of a non-linear simultaneous equation obtained from a pseudo distance to a GPS satellite, a distance to a PHS base station, and a direction cosine vector of each GPS satellite and PHS base station with respect to an estimated positioning position 2. A position calculating unit for calculating a position of a least squares convergence for obtaining a latitude and a longitude of a position and a clock bias. Position detection device. 4. A first weighting unit for multiplying a weighting coefficient equal to a pseudo distance to each GPS satellite obtained by the pseudo distance measuring unit, and a weight to the PHS base station obtained by the PHS radio field intensity measuring unit 4. The position detecting device according to claim 3, further comprising a second weighting unit for multiplying the coefficient, and providing the weighted value to the least-squares convergence calculation positioning position calculating unit. 5. A first method for individually multiplying a pseudo distance to each GPS satellite obtained by a pseudo distance measuring unit by a weighting factor.
Weighting unit and PHS obtained by the PHS radio wave intensity measurement unit
4. The position detecting device according to claim 3, further comprising a second weighting unit for multiplying the distance to the base station by a weighting coefficient, and providing the weighted value to the least-squares convergence calculation positioning position calculating unit. . 6. A PHS receiving unit in which the positioning operation processing unit communicates with a pseudo distance measuring unit for obtaining a pseudo distance to each GPS satellite based on GPS signals from a plurality of GPS satellites received by a GPS receiving unit. A PHS radio field intensity measurement unit for obtaining a distance to a PHS base station at a known position based on the position of the PHS base station and the reception intensity, and a pseudo distance and a PHS radio field intensity measurement unit obtained by the pseudo distance measurement unit GP that receives GPS signals at a distance to the PHS base station
A Kalman filter positioning position calculation unit for obtaining the latitude and longitude of the positioning position and a clock bias using a Kalman filter in consideration of the dynamic characteristics of a mobile body equipped with an S antenna and a PHS antenna communicating with the PHS base station. The position detecting device according to claim 1. 7. The position detecting device according to claim 6, wherein an initial estimated value of the positioning position used in the Kalman filter positioning position calculating unit is a position of a PHS base station with which a PHS receiving unit is communicating.