JPH10253736A - Mobile position detecting system and mobile position detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect the position of a mobile even in a place inaccessible directly through a GPS satellite and to reduce the size and cost of a portable terminal. SOLUTION: A portable terminal 2 fixed to a mobile 1 to be detected transmits a radio signal including an ID code of mobile and transmission time information. A searching mobile 4 receives a radio signal from the portable terminal and a radio signal including positional information and transmission time information from GPS satellites 6a-6d. An operating circuit at a base station 7 calculates the positional information of the searching mobile based on a received radio signal of GPS satellite and the receiving time information thereof and then calculates the position of the mobile at each time based on the calculated positional information of the searching mobile, received signal of the portable terminal and the receiving time information thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving object position detecting system and a moving object position detecting device for detecting the position of an object moving at approximately the walking speed.

[0002]

2. Description of the Related Art Conventionally, an emergency call support service has been provided by an emergency call device for an elderly or sick person to make an emergency call. In this emergency call support service, when an elderly or sick person carries a transmitter and presses an operation button in an emergency, the user's I
A D code or the like can be reported to the emergency report destination. There is also known a current position reporting system for reporting the current position of a person carrying a transmitter to a specific report destination in an emergency.

[0003] As a conventional current position notification system of this type, for example, there is one described in Japanese Patent Application Laid-Open No. 8-180286. In the current position reporting system described in this publication, the portable terminal device receives position information and time information of each GPS satellite from a plurality of GPS satellites, and calculates the longitude, latitude, altitude, and the like of the receiving point. The current position information and the ID code are converted into radio signals based on the protocol of the PHS system, and are transmitted at regular intervals to the monitoring center as a report destination.

[0004] The radio base station receives a radio signal from a portable terminal device and connects a line to a monitoring center. In the monitoring center, the current position information and ID from the portable terminal device
Identify the caller and current location from the code and arrange an ambulance.

[0005]

However, in the conventional current position reporting system, for example, when the portable terminal device is located in a valley of a building or the like, the portable terminal device is GP.
The signal from the S satellite could not be received directly. For this reason, it has not been possible to obtain position information of a position detection moving body such as a person carrying the portable terminal device at an arbitrary time.

Further, the conventional portable terminal device receives a signal from a GPS satellite and transmits the position information of the position-detected moving body at an arbitrary time to the radio base station. That is,
Since the portable terminal device has a transmission function and a reception function, it has been large and expensive.

SUMMARY OF THE INVENTION The present invention is directed to a moving object position detecting system and a moving object position detecting method capable of detecting the position of a moving object whose position is to be detected even in a place where GPS satellites cannot directly receive the moving object, thereby making it possible to reduce the size of the portable terminal at low cost. It is an object to provide a device.

[0008]

The present invention employs the following means in order to solve the above-mentioned problems. The mobile object position detecting system according to claim 1, wherein the wireless transmitting apparatus is attached to the position-detected moving object and transmits a radio signal including identification information for identifying the position-detected moving object and transmission time information. An exploratory moving body that receives a radio signal transmitted from the radio transmitting apparatus and receives a radio signal including position information and transmission time information transmitted from the position information transmitting apparatus; The position information of the exploration moving body is calculated based on the radio signal of the position information transmitting apparatus and the reception time information of the radio signal, and the calculated position information of the exploration moving body, the radio signal of the radio transmission apparatus, and the And a position calculating device for calculating the position of the position detection moving body at each time based on the reception time information of the wireless signal.

According to the present invention, when the wireless transmission device attached to the position detection movable body transmits a wireless signal including the identification information and the transmission time information, the search movable body is transmitted from the wireless transmission device. Receiving a wireless signal, and receiving a wireless signal including position information and transmission time information sent from the position information transmitting apparatus. Then, the position calculation device calculates the position information of the search vehicle based on the wireless signal of the position information transmitting device received by the search vehicle and the reception time information of the wireless signal, and calculates the calculated position information of the search vehicle, Based on the wireless signal of the wireless transmission device and the reception time information of the wireless signal, the position of the position detection moving body at each time is calculated.

[0010] That is, the position of the position-detected moving body can be calculated by interposing the search moving body between the position information transmitting device and the radio transmitting device. Therefore, even in a place where the position information transmitting device such as a GPS satellite cannot directly receive, the position of the position detection moving object can be known by arranging the exploration moving object at an appropriate position. Since the wireless transmission device only transmits a wireless signal including identification information and transmission time information, the wireless transmission device has only a transmission function, is small and inexpensive, and even if the wireless signal of the wireless transmission device reaches the exploration moving body. As a result, the transmission power is small.

According to a seventh aspect of the present invention, there is provided a moving object position detecting device, comprising:
A receiving unit that receives a wireless signal including identification information and transmission time information for identifying the position detection moving object transmitted from a wireless transmission device attached to the position detection moving object, provided on the exploration moving object; 1 receiving means, a second receiving means provided in the exploration moving body, for receiving a radio signal including position information and transmission time information sent from the position information transmitting device, and a receiving means provided in the exploration moving body. The position information of the exploration moving body is calculated based on the radio signal of the position information transmitting apparatus and the reception time information of the radio signal, and the calculated position information of the exploration moving body, the radio signal of the radio transmission apparatus, and the And a position calculating device for calculating the position of the position detection moving body at each time based on the reception time information of the wireless signal.

According to the invention, in the exploration moving body,
The first receiving means receives a wireless signal including identification information and transmission time information sent from a wireless transmitting device attached to the position detection movable body, and the second receiving means sends a wireless signal from the position information transmitting device. The wireless signal including the received position information and transmission time information is received. The position calculating device calculates the position information of the exploration mobile based on the received radio signal of the position information transmitting device and the reception time information of the radio signal, and calculates the calculated position information of the exploration mobile and the radio transmission device. Based on the radio signal and the reception time information of the radio signal, the position of the position detection target moving body at each time is calculated.

That is, a search moving body is interposed between the position information transmitting apparatus and the radio transmitting apparatus, and the position of the position detection moving body is calculated by the moving body position detecting device provided on the search moving body. it can. Therefore, even in a place where the position information transmitting device such as a GPS satellite cannot directly receive, the position of the position detection moving object can be known by arranging the exploration moving object at an appropriate position.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of a moving object position detecting system and a moving object position detecting apparatus according to the present invention.

<First Embodiment> FIG. 1 shows a schematic configuration diagram of a moving object position detecting system according to a first embodiment. The moving object position detection system shown in FIG. 1 is for detecting the position of a moving object 1 such as an infant who easily gets lost, a wandering old man, a victim in mountainous areas, and a cart or the like at a golf course. It is. The moving object position detection system includes a position detecting moving object 1 (1a, 1b) and a mobile terminal 2 as a wireless transmission device attached to the position detecting moving object 1 for detecting the position of the position detecting moving object 1. (2a, 2b), the mobile terminal 2 and the GPS (gl
exploration mobile 4, which receives a radio signal from an obal positioning system (satellite) 6a to 6d;
Radio signal from exploration mobile 4 and four GPS satellites 6a
And a terminal 9a and 9b for receiving a radio signal from the base station 7.

The portable terminal 2 is required to be extremely small in size depending on the application. For example, the portable terminal 2 has a size of a ring, and stores an ID code and transmission time information as identification information set in advance to identify each individual. The set of wireless signals is intermittently transmitted to the exploration mobile unit 4.

The exploration moving object 4 is located in an area where the position detecting moving object 1 is considered to be present and in a region where the transmission radio wave from the position detecting moving object 1 can be received. Is mounted on an object 3 that moves at a sufficiently high relative speed with respect to The object 3 is, for example, a radio-controlled airplane or a car provided for searching. In addition, the exploration mobile 4 can directly receive wireless signals from the GPS satellites 6a to 6d.

The exploration mobile unit 4 receives the ID code and the transmission time information transmitted intermittently from the portable terminal 2 and stores the reception signal together with the reception time information as a demodulation reception signal. GPS satellites 6a to 6d
Are stored as demodulated reception signals together with their respective reception times, and these signals are encoded and modulated again and transmitted to the base station 7.

The base station 7 uses position information and transmission time information received from the four GPS satellites 6a to 6d at each position when the search mobile 4 moves, and a clock in the search mobile 4 at each position. Each position of the exploration mobile 4 is calculated based on the measured reception time information. Base station 7
Calculates the position of the mobile terminal 2 based on the position coordinates of the exploration mobile 4, transmission time information of the mobile terminal 2, and reception time information when the exploration mobile 4 receives the transmission time information.

The base station 7 converts the position information and time information of the portable terminal 2 into the terminal 9a or the terminal 9b corresponding to the ID code.
Send to Display unit 10a in terminal 9a or terminal 9b
The display unit 10b displays the position of the mobile terminal 2 on each map at each time based on the position information of the mobile terminal 2.
In the first embodiment, two mobile terminals are used.
There may be three or more mobile terminals having a D code.

Next, a specific circuit configuration of the moving object position detecting system according to the first embodiment will be described. First, the mobile terminal 2 will be described. FIG. 2 shows a specific circuit configuration diagram of the mobile terminal 2. The portable terminal 2 includes an ID generator 21 and a clock 2
2. Insertion circuit 23, encoding / modulation circuit 24, transmitting unit 2
5, a transmission modulation on / off circuit 26 and a transmission antenna 27 are provided.

An ID generator 21 generates an ID code, which is identification information unique to the portable terminal 2, and a clock 22 measures an accurate time. The insertion circuit 23 includes an ID generator 21
And the time signal from the clock 22 are synthesized and output to the encoding / modulation circuit 24. The encoding / modulation circuit 24 encodes and modulates the ID code and the time signal. The transmitting unit 25 transmits the modulated ID code and the time signal from the transmitting antenna 27 as a transmission signal. The transmission modulation on / off circuit 26 controls the transmission unit 25 and the encoding / modulation circuit 24 to suppress transmission power.

The clock 22 as a time measuring means measures the time for each ID code of the portable terminals 2a and 2b. The transmission modulation on / off circuit 26 as transmission control means
The wireless signal is transmitted at a transmission timing different from the transmission timing of the other portable terminal based on the time measured by 2. Transmission modulation off circuit 26 of the mobile terminal 2a, as shown in FIG. 3, the portable terminal 2a within a period of Delta] t ₀ moves position _{X 11, X 12, X 13} , signals sequentially in X ₁₄ S _11, S
_12, and transmits the S _13, S _14. The transmission modulation on / off circuit 26 of the mobile terminal 2b sets the mobile terminal 2b within the next Δt ₀ period.
Signal S at the position X ₂₁ , X ₂₂ , X ₂₃ , X ₂₄ where
_21, and transmits the _{S 22, S 23, S 24} . The transmission modulation off circuit of each mobile terminal 26 transmits a signal for each period T _0. As described above, signals are transmitted from the mobile terminals 2a and 2b to the exploration mobile unit 4 in a time-division manner.
Then, each signal between the portable terminals 2a and 2b can be easily separated.

Further, the portable terminal 2 has only a transmission function and does not have any self-calculation function or reception function as in the related art, so that it is inexpensive, small, and lightweight. Also, since the transmission power only needs to reach the exploration mobile 4,
The size can be reduced, and power can be saved.

Next, the search moving body 4 will be described. FIG. 4 shows a specific circuit configuration diagram of the search moving object 4 according to the first embodiment. The exploration moving body 4 includes a GPS receiving antenna 41, a GPS
Receiver 42, demodulation / decoding circuits 43a to 43d, clock 4
4, a receiving antenna 45, a terminal receiving unit 46, a demodulation / decoding circuit 47, a memory 48, a memory control circuit 49, an encoding / modulation circuit 50, a transmission unit 51, and a transmission antenna 52.

Terminal receiving section 46 as first receiving means
Receives a signal including an ID code and transmission time information intermittently transmitted from the mobile terminal 2 via the reception antenna 45, and a demodulation / decoding circuit 47 demodulates / decodes the received signal to obtain an ID code and Obtain transmission time information. Memory 4
8 stores the ID code and the transmission time information from the portable terminal 2 together with the reception time information measured by the clock 44 in the memory 48 under the control of the memory control circuit 49.

When the terminal receiving section 46 receives a signal from the portable terminal 2, the GPS receiving section 42 as a second receiving means
Receives signals including the position information and the transmission time information from the four GPS satellites 6a to 6d via the GPS receiving antenna 41, and demodulates and decodes the signals on four channels (CH).
a to 43d are the four received by the GPS receiver 42.
Simultaneously demodulate and decode from the two GPS satellites 6a to 6d to obtain position information and transmission time information. The memory 48 stores the four decoded Gs under the control of the memory control circuit 49.
The position information and the transmission time information from the PS satellites 6a to 6d are stored together with the reception time information measured by the clock 44.

The encoding / modulation circuit 50 encodes and modulates the position information and time information of the GPS satellite and the ID code and time information of the portable terminal 2 stored in the memory 48. The transmission unit 51 transmits the signal modulated by the encoding / modulation circuit 50 to the base station 7 via the transmission antenna 52.

Note that, as shown in FIG.
Moves from the position P1 to the position P4 as the portable terminal 2 moves from the position X1 to the position X4. Also,
The four GPS satellites 6a to 6d are fixedly arranged at positions Q1 to Q4. For this reason, the data from the mobile terminal 2 and the four GPs for each of the positions P1 to P4 of the exploration moving body 4
Data from the S satellites 6a to 6d is stored in the memory 48.

The data stored in the memory 48 and transmitted to the base station 7 becomes the following data string, and is deleted from the memory 48 when the base station 7 can normally receive the data. From the following data sequence, the position X of the mobile terminal 2
The average coordinate position of 1, X2, X3, X4 is 16
It is obtained as a value at the average time of the point. Here, it is assumed that the moving distance of the mobile terminal 2 from the position X1 to the position X4 is sufficiently smaller than the moving distance of the search moving body 4 from the position P1 to the position P4.

In this case, four GPS satellites 6a to 6d are used to know three parameters of the absolute position (latitude, longitude and altitude) of each exploration mobile unit 4. When only two parameters are required, three points (positions) of the exploration mobile unit 4 and the mobile terminal 2 may be used, and only nine points are required for the following data.

Example of data sequence (a) Data delay time from satellite 6a | Data from X1 | Data reception time at P1 of exploration mobile unit 4, data delay time from satellite 6b | P1 of exploration mobile unit 4
Data reception time at, data delay time from satellite 6c | data reception time at P1 of exploration mobile unit 4,
Data delay time from satellite 6d | P of exploration mobile 4
(B) Data delay time from satellite 6a | Data from X2 | Data reception time at P2 of exploration mobile unit 4, data delay time from satellite 6b | P2 of exploration mobile unit 4
Data reception time at, data delay time from satellite 6c | data reception time at P2 of exploration mobile unit 4,
Data delay time from satellite 6d | P of exploration mobile 4
(C) Data delay time from satellite 6a | Data from X3 | Data reception time at P3 of exploration mobile unit 4, data delay time from satellite 6b | P3 of exploration mobile unit 4
Data reception time at, data delay time from satellite 6c | data reception time at P3 of exploration mobile unit 4,
Data delay time from satellite 6d | P of exploration mobile 4
3 Data reception time at satellite 3 (d) Data delay time from satellite 6a | Data from X4 | Data reception time at P4 of exploration mobile unit 4, data delay time from satellite 6b | P4 of exploration mobile unit 4
Data reception time at satellite, data delay time from satellite 6c | data reception time at exploration mobile 4 at P4,
Data delay time from satellite 6d | P of exploration mobile 4
4, the data delay time from the satellite is the difference between the data reception time from the satellite and the data transmission time, and the data from the position X1 of the portable terminal 2 is
The information includes an ID code and transmission time information.

These data strings are stored in the memory 48 and then processed collectively by the base station 7. This is for storing the raw data of the positional information of the exploration mobile unit 4 corresponding to the reception time from the mobile terminal 2 in the memory 48 with a minimum error, and for performing the calculation requiring a long time as much as possible.

Next, the accuracy of the clock 22 of the portable terminal 2 and the clock 44 of the exploration mobile unit 4 will be described. The speed of light is 0.3
Since the movement proceeds at m / nS, a clock capable of measuring up to 33 nS accuracy is required to obtain a coordinate accuracy of 10 m. Therefore, in this case, a clock pulse for a clock having a minimum unit of, for example, 10 ns is required. Since the clock 22 of the portable terminal 2 and the clock 44 of the exploration mobile 4 may have different absolute values, these clocks may be relatively inexpensive clocks.

In this case, if a time label for one day is attached, 24 * 60 * 60 / (10 * 10 ^-9 ) = 8.6.
At ** 10 ¹² , the time information is transmitted from the portable terminal 2 as a time label of about 45 bits, and the time information is stored in the memory 48 of the exploration mobile 4.

Next, the base station 7 will be described. FIG. 6 shows a specific circuit configuration diagram of the base station 7. The base station 7 includes a receiving antenna 71, a receiving unit 72, a demodulation / decoding circuit 73, a memory 7
4. It has a memory control circuit 75, an arithmetic circuit 76 as position calculating means, a data conversion unit 77, a transmission unit 78, a reception antenna 79, and a GPS receiver 80.

The receiving section 72 receives a signal from the exploration mobile 4 via the receiving antenna 71. Demodulation / decoding circuit 7
3 demodulates and decodes a signal from the exploration mobile unit 4 and outputs the signal at each position P1, P2, P3, P4 of the exploration mobile unit 4.
The position information, transmission time information and reception time information of the two GPS satellites 6a to 6d, and the ID code, transmission time information and reception time information of the portable terminal 2 are obtained. The memory 74 stores the position information and the time information of the GPS satellite and the ID code and the time information of the portable terminal 2 which are decoded under the control of the memory control circuit 75.

The arithmetic circuit 76 stores the position information and transmission time information from the four GPS satellites 6a to 6d at the respective positions P1, P2, P3, and P4 of the exploration mobile unit 4 stored in the memory 74, and the position P1, Each position P1, P2, P3, P of the exploration mobile 4 based on the reception time information measured by the clock 44 in the exploration mobile 4 at P2, P3, P4.
Calculate 4.

Here, the positioning calculation will be described. The coordinates of the object whose exact position is known are (U1, V1, W1), and the coordinates of the measured object are (X, Y, Z). Here, a radio wave is emitted from one object to the other object, the arrival time ΔTR at which the radio wave arrives at the other object is accurately measured, and the measured ΔTR is multiplied by the speed of light C to obtain a distance between the two objects. You can know the exact distance. Here, the following general formula is established.

[0040]

## EQU1 ## (U1-X) ² + (V1-Y) ² + (W1-
Z) ² = (ΔTR * C) ² arrival time ΔTR is time T0 (transmission time measured by a built-in clock on the transmission side and transmitted as data)
And the difference between the time T1 (reception time measured by the internal clock of the receiving side) and the difference Ter of the absolute value of each clock itself and the sum Terr of the delay time due to the signal processing time.

That is, ΔTR = T1-T0 + Terr
Becomes Therefore,

## EQU2 ## (U1-X) ² + (V1-Y) ² + (W1-
Z) ² = {(T1-T0 + Terr) * C} ² holds.

Here, the unknowns are X, Y, Z, and Terr.
And the other values are known. Therefore,
If the data including the transmission time from the four transmitters at different known coordinates and the reception time of the data are measured by the built-in clock of the receiver, these non-simultaneous equations can be obtained by the iterative method from the following four equations. X, Y, Z, and Terr can be obtained.

[0043]

## EQU3 ## ^{(U1-X) 2 + (} V1-Y) 2 + (W1-Z) 2 = {(T11-T01 + T err) * C} 2 (U2-X) 2 + (V2-Y) 2 + ^{(W2-Z) 2 = {} (T12-T02 + T err) * C} 2 (U3-X) 2 + (V3-Y) 2 + (W3-Z) 2 = {(T13-T03 + T err) * C} 2 (U4-X) ² + (V4-Y) ² + (W4-Z) ² = {(T14-T04 + T err) * C} ² (1) where Ui, Vi, Wi, T1i, T0i Is a known value. Further, since each T1i is measured by the same clock and the absolute time error between T1 and T0 is included in Terr, there is no need to sense it. However, it is assumed that the relative time is also accurate.

FIG. 7 shows GPS signals from the GPS satellites 6a to 6d. The microwave carrier of this GPS signal includes two carriers, a carrier L1 having a frequency of 1.57542 GHZ and a carrier L2 having a frequency of 1.2276 GHZ.
Only used. At present, 24 GPS satellites are arranged to cover each point in the world, and different C / A codes are assigned to them.

1.5754 from the GPS satellites 6a to 6d
A 1023 bit length called a C / A code unique to each satellite centered on 2GHZ and a transmission rate of 1.023
MBIT / S pseudo-noise code (PRN code pseudoo)
Random noise code is weighed in a spread spectrum system. Even if the transmission frequency of each GPS satellite is the same, signals spread with different codes can be separated without occurrence of interference, and demodulated by performing despreading on the receiving side. The difference between the despread value of this PRN code string and the despread signal generated from its own clock is (T14-T0
4 ÷ Terr).

As the GPS navigation data, 1
5 per 300 bits per frame from one GPS satellite
50 parity values for frames, time information, orbit information, etc.
It is transmitted by BPS. Kepler's equation is solved from the received information, and the accurate GPS satellite positions Ui, Vi,
Wi (i = 1 to 4) can be obtained.

The arithmetic circuit 76 solves the above equation (1) for each of the four positions P (X, Y, Z) on the trajectory of the exploration moving body 4, and calculates the four positions P (X, Y). , Z) to calculate the coordinates of the four positions P (X, Y, Z) at each T0i.

Next, the coordinates of the position P are represented by Xi, Yi, Z
i, and the coordinates of the portable terminal 2 with respect to P1 are X0, T0,
Assuming that Z0, for each point of P1, P2, P3, P4,

(X1-X0) ² + (Y1-Y0) ² + (Z1-Z0) ² =） (T11-T01 + Terr) * C) ² (X2-X0 + Δ1) ² + (Y2-Y0 + Δ2) ² + (Z2-Z0 + Δ3) ² = ｛(T12-T02 + Terr) * C) ² (X3-X0 + Δ4) ² + (Y3-Y0 + Δ5) ² + (Z3-Z0 + Δ6) ² = ｛(T13-T03 + Terr) * C) ² (X4 −X0 + Δ7) ² + (Y4-Y0 + Δ8) ² + (Z4-Z0 + Δ9) ² = ｛(T14−T04 + Terr) * C) ² (2)

Here, Δi is X0,
It is the moving distance from Y0, Z0. At this time, Δi is sufficiently small with respect to other values and can be ignored in each (). This is because the relative moving distance of the exploration mobile 4 with respect to the mobile terminal 2 is sufficiently large.

The arithmetic circuit 76 sets each Δi = O,
By solving equation (2), the unknowns X0, Y0, Z0, T
err is calculated. At this time, each T1i is the reception time of the data of the exploration mobile unit 4, and T0i is the transmission time of the data of the portable terminal 2. Terr is the sum of the absolute error of the clocks 22 and 44 of the mobile terminal 2 and the exploration mobile unit 4 and the delay of the signal processing time, and is the value when the respective P points were previously obtained from the positions of the GPS satellites 6a to 6d. The value is, of course, different. In this way, the arithmetic circuit 76 can calculate the position of the portable terminal 2 as a value at the average time of each of T1i and T0i.

The GPS receiver 80 is installed in the base station 7 whose coordinates are known in advance, and the four GPS satellites 6a to 6d
And receives a signal including position information and time information. The arithmetic circuit 76 receives the four GPS signals received by the GPS receiver 80.
The position of the base station 7 is calculated from the position information and time information of the satellites 6a to 6d. The arithmetic circuit 76 calculates the calculated base station 7
The calculated position of the exploration mobile 4 is corrected using the difference between the position information of the base station 7 and the coordinate data of the base station 7 as a correction value. Thereby, the accuracy of the positioning calculation by the GPS can be improved.

Further, the data conversion section 77 includes the arithmetic circuit 7
6, the position information, time information, and I of the mobile terminal 2
Convert the D code into a wireless signal. The wireless signal including the position information, the time information, and the ID code of the mobile terminal 2 is transferred to each terminal 9a, 9b for each ID code. Terminal 9a,
In 9b, the position of the portable terminal 2 can be displayed on each map at each time from the position information. Communication between the base station 7 and each of the terminals 9a and 9b may be performed wirelessly or may be performed by wire.

As described above, according to the first embodiment, the GPS
The exploration mobile 4 is interposed between the satellites 6a to 6d and the mobile terminal 2, and the moving distance of the exploration mobile 4 per unit time is sufficiently large with respect to the mobile distance of the mobile terminal 2, so that the accurate satellite position is obtained. The position of the search vehicle 4 is calculated from the information, and the position of the mobile terminal 2 at each time is calculated based on the calculated position of the search vehicle 4. The position of each time of the mobile terminal 2 is the position of each time of the position detection moving body 1.

Therefore, even if the mobile terminal 2 and the position detection moving object 1 are located at a position where radio waves from the GPS satellites cannot directly reach, for example, a valley of a building, the exploration moving object 4 is appropriately By arranging the mobile terminal 2 at an appropriate position, the coordinate positions of the mobile terminal 2 and the position detection target moving body 1 can be known, so that the mobile terminal 2 can be tracked over a wider range.

Since the mobile terminal 2 and the exploration mobile unit 4 are relatively close to each other, the transmission power from the mobile terminal 2 may be small, and the mobile terminal 2 can be downsized. Furthermore, even if there are a plurality of mobile terminals 2a and 2b, the transmission signal is transmitted from each mobile terminal to the exploration mobile unit 4 in a time-sharing manner, so that the exploration mobile unit 4 can identify the transmission signal from each mobile terminal. The position of each portable terminal 2a, 2b can be detected by one exploration moving body 4. Further, by providing the arithmetic circuit 76 in the base station 7, the exploration moving body 4 can have a simpler configuration.

<Second Embodiment> Next, a moving object position detecting system and a moving object position detecting device according to a second embodiment of the present invention will be described. In the moving object position detection system according to the second embodiment, the arithmetic circuit 7 described in the first embodiment is added to the exploration moving object 4.
6 is provided. FIG. 8 shows a specific circuit configuration diagram of the search moving body 4.

The search vehicle 4 shown in FIG. 8 includes a GPS receiving antenna 41, a GPS receiving unit 42, and a demodulation / decoding circuit 43a.
43d, clock 44, receiving antenna 45, terminal receiving unit 4
6, demodulation / decoding circuit 47, memory 48, memory control circuit 49, arithmetic circuit 76, encoding / modulation circuit 50, transmitting section 5
1. It has a transmitting antenna 52, and these constitute a mobile object position detecting device.

In the exploration mobile unit 4 shown in FIG. 8, the terminal receiving unit 46 receives a signal including an ID code and transmission time information transmitted intermittently from the portable terminal 2 via the receiving antenna 45, and demodulates / receives the signal. The decoding circuit 47 demodulates and decodes the received signal to obtain an ID code and transmission time information.
The memory 48 stores the ID code and the transmission time information from the portable terminal 2 together with the reception time information measured by the clock 44 in the memory 48 under the control of the memory control circuit 49.

When the terminal receiving section 46 receives a signal from the portable terminal 2, the GPS receiving section 42 transmits a signal including position information and transmission time information from the four GPS satellites 6 a to 6 d via the GPS receiving antenna 41. And each of the 4CH demodulation / decoding circuits 43a to 43d
2 demodulates and decodes the signal received at
Position information and transmission time information from the PS satellites 6a to 6d are obtained. The memory 48 stores the decoded position information and transmission time information from the four GPS satellites 6 a to 6 d together with the reception time information measured by the clock 44 under the control of the memory control circuit 49.

Next, the arithmetic circuit 76 calculates the position information and the transmission time information from the four GPS satellites 6a to 6d at the respective positions P1, P2, P3, and P4 of the exploration mobile unit 4 stored in the memory 48, and By solving the equation (1) based on the reception time information measured by the clock 44 in the search moving body 4 at the positions P1, P2, P3, and P4, the search moving body 4
Is calculated for each position P1, P2, P3, P4.

Further, the arithmetic circuit 76 calculates the equation (2) based on the information of the positions P1, P2, P3, and P4 of the exploration moving body 4 and the ID code, transmission time information and reception time information from the portable terminal 2. By solving the above, the position of the mobile terminal 2, that is, the position of the position-detected moving body 1 is calculated for each time.

The encoding / modulation circuit 50 encodes and modulates the position information, ID code and time information of the portable terminal 2 calculated by the arithmetic circuit 76. The transmission unit 51 performs encoding /
The signal modulated by the modulation circuit 50 is transmitted to the transmitting antenna 52.
To the base station 7 via.

FIG. 9 shows a specific circuit configuration diagram of the base station. In the base station shown in FIG. 9, when the receiving unit 72 receives a signal from the exploration mobile 4 via the reception antenna 71, the demodulation / decoding circuit 73 demodulates and decodes the signal from the exploration mobile 4, The position information, ID code, and time information of the portable terminal 2 are obtained. The memory 74 stores the position information and ID of the mobile terminal 2 decoded under the control of the memory control circuit 75.
The data conversion unit 77 stores the code and the time information, and converts the position information, the time information, and the ID code of the mobile terminal 2 into a wireless signal. Position information, time information and I of the mobile terminal 2
The radio signal including the D code is transmitted to each terminal 9 for each ID code.
a, 9b.

As described above, the exploration moving object 4
Even if the position of the portable terminal 2 is calculated based on the calculated positions, the same effect as the effect of the first embodiment can be obtained. Further, by providing the search moving body 4 with the arithmetic circuit 76, a moving body position detecting device can be configured in the search moving body 4, and the position of the position detection moving body 1 in the search moving body 4 is calculated. be able to.

[0065]

According to the present invention, an exploration mobile receives a radio signal from a radio transmission device, receives a radio signal including position information and transmission time information from a position information transmission device,
The position calculation device calculates the position information of the search moving object based on the wireless signal of the position information transmitting device and the reception time information of the wireless signal, and calculates the calculated position information of the search moving object, the wireless signal of the wireless transmission device, and the wireless signal of the wireless transmission device. The position at each time of the position detection moving body is calculated based on the signal reception time information.

That is, the position of the position-detected moving object can be calculated by interposing the search moving object between the position information transmitting device and the radio transmitting device. Therefore, even in a place where a position information transmitting device such as a GPS satellite cannot directly receive, the position of the position detection moving body can be determined by arranging the exploration moving body at an appropriate position. Since the wireless transmission device only transmits a wireless signal including identification information and transmission time information, the wireless transmission device has only a transmission function, is small and inexpensive, and even if the wireless signal of the wireless transmission device reaches the exploration moving body. As a result, the transmission power is small.

Further, a search moving body is interposed between the position information transmitting apparatus and the radio transmitting apparatus, and the position of the position detecting moving body at each time is calculated by the moving body position detecting device provided on the search moving body. can do.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a moving object position detection system according to a first embodiment.

FIG. 2 is a specific circuit configuration diagram of the portable terminal.

FIG. 3 is a diagram illustrating transmission timing by time division of each mobile terminal.

FIG. 4 is a specific circuit configuration diagram of the search moving body according to the first embodiment;

FIG. 5 is a diagram illustrating a relationship between an exploration moving body that moves to each position as the mobile terminal moves and four fixedly arranged GPS satellites.

FIG. 6 is a specific circuit configuration diagram of the base station according to the first embodiment.

FIG. 7 is a diagram showing a GPS signal from a GPS satellite.

FIG. 8 is a specific circuit configuration diagram of a search moving body according to the second embodiment.

FIG. 9 is a specific circuit configuration diagram of the base station according to the second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Position detection mobile body 2 Mobile terminal 4 Exploration mobile body 6a-6d GPS satellite 7 Base station 9a, 9b Terminal 10a, 10b Display part 21 ID generator 22,44 Clock 24,50 Encoding / modulation circuit 42 GPS receiving part 43a to 43d, 73 Demodulation / decoding circuit 46 Terminal receiving unit 49, 75 Memory control circuit 48, 74 Memory 52, 78 Transmission unit 76 Operation circuit 77 Data conversion unit

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H04Q 7/38 H04B 7/26 109S

Claims (7)

[Claims] 1. A wireless transmission device attached to a position-detected moving object, for transmitting a wireless signal including identification information for identifying the position-detected moving object and transmission time information, and transmitted from the wireless transmission device. An exploratory moving body that receives the received radio signal and also receives a radio signal including the position information and the transmission time information sent from the position information transmitting device; and the radio of the position information transmitting device received by the searching moving body. The position information of the exploration moving object is calculated based on the signal and the reception time information of the radio signal, and the position information of the exploration moving object is calculated, based on the calculated position information of the exploration moving object, the radio signal of the wireless transmission device and the reception time information of the radio signal. A position calculating device for calculating a position of the position-detected moving object at each time. 2. The position calculation device is provided in a base station that receives a radio signal and reception time information of the position information transmission device and a radio signal and reception time information of the radio transmission device received by the exploration mobile. 2. The method according to claim 1, wherein
The moving object position detection system according to the above. 3. The position calculating device is provided in the search moving body, and the search moving object is position information, the reception time information, and the identification of the position detection moving object calculated by the position calculating device. The mobile object position detecting system according to claim 1, further comprising transmitting means for transmitting information to the base station. 4. When the search moving body moves to each position at each time, the search moving body stores a radio signal and reception time information of the wireless transmission device at each time of the search moving body. 4. The storage device according to claim 1, further comprising a storage unit configured to store a wireless signal transmitted from each of the plurality of position information transmitting devices at a reception time of the wireless signal at each time. The moving object position detection system according to the item. 5. The position calculating apparatus according to claim 1, wherein said plurality of position information transmitting apparatuses store radio signal and reception time information of each of said plurality of position information transmission times stored in said storage means. Calculating position information, and calculating the position of each position of the position-detected moving object at each time based on the calculated position information of the exploration moving object, the radio signal of the wireless transmission device at each time, and the reception time information. 5. The method according to claim 4, wherein
The moving object position detection system according to the above. 6. The wireless transmission device is provided for each of the identification information, each wireless transmission device is provided with a timer for measuring time, and the transmission of another wireless transmission device is performed based on the time measured by the timer. The mobile object position detection system according to any one of claims 1 to 5, further comprising: a transmission control unit configured to transmit the wireless signal at a transmission timing different from a timing. 7. A wireless device provided on an exploration moving object and including identification information for identifying the position detecting moving object transmitted from a wireless transmitting device attached to the position detecting moving object and transmission time information. First receiving means for receiving a signal; second receiving means provided on the exploration mobile body for receiving a radio signal including position information and transmission time information sent from the position information transmitting device; And calculates the position information of the exploration moving body based on the received radio signal of the position information transmitting apparatus and the reception time information of the radio signal, and calculates the calculated position information of the exploration moving body, the radio transmission apparatus A position calculating device for calculating the position of the position-detected moving object at each time based on the wireless signal and the reception time information of the wireless signal.