JPH0560854A - Transmitter position measuring system, transmission method, and reception method - Google Patents

Abstract

PURPOSE:To obtain an intermittent position coordinate of a body to be measured with a simple system which does not using a reference transmitter or a synchronization circuit. CONSTITUTION:Reference stations 1a-1d in a position-measuring system receive a pseudo noise signal from a body to be measured and has a matching filter regarding the pseudo noise signal which is allocated to the body to be measured. A measuring means 4 measures an arrival delay time of a signal which is detected by other reference stations in reference to a detection time of a signal which is detected initially out of correlation pulse signals which are obtained by a detector.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmitter position measuring system, a transmitting method and a receiving method, and more particularly to a transmitter position measuring device for receiving a radio wave emitted from an object to be measured and measuring the coordinates of the position of the object to be measured. The present invention relates to a system, a transmission method, and a reception method. For example, it is applied to local area wireless communication, factory automation, home automation and the like.

[0002]

2. Description of the Related Art Japanese Patent Application No. 2-3
No. 5550 has "transmitter position measuring system and transmitter". This is a transmitter position measurement system that can obtain accurate position coordinate information of the measured object in a limited area such as an indoor environment, and the transmitter that transmits the pseudo noise signal and the time when the pseudo noise signal is generated. The system measures the positions of the synchronizing circuits and the transmitters of a plurality of reference stations installed in the measurement area by holding the clock as the reference of (1) on the measured object. This system allows tracking of position in real time, but each reference station requires a synchronization circuit for pseudo noise signals,
The circuit configuration becomes complicated.

Further, the above-mentioned application uses a reference station as a position measuring system when it is not necessary to continuously track the position, such as when the object to be measured holding the transmitter moves slowly or moves little. We are considering a system that can use a matched filter for each pseudo noise signal without using a synchronous circuit to simplify the circuit configuration and perform position measurement at certain time intervals. However, since each reference station calculates the arrival time of the signal transmitted from the transmitter based on the clock connected to the computer for calculating the coordinates, the time difference between each reference station due to the delay in the connection cable between the computer and each reference station. When an error occurs, an error will occur in the calculation of coordinates.

Further, the previously proposed Japanese Patent Application No. 3-1139.
The No. 27 “Transmitter Positioning System” is designed to solve the problems caused by different time differences at each reference station.
A reference oscillator is installed at a known coordinate in the measurement area, and a pseudo noise signal different from that of the DUT is emitted at the same transmission interval as that of the DUT, but at a different time, and each reference station is based on this signal. We have proposed a transmitter position measurement system that can calculate the arrival time and reduce the time error of the coordinate calculation of the measured object. However, this system required the installation of a reference transmitter within the measurement area.

[0005]

[Purpose] The present invention has been made in view of the above circumstances, and shows a time reference of a reference transmitter or a clock when delay time in a connection cable between a computer and each reference station is not a problem. A transmitter that calculates the coordinates of the DUT by measuring the delay time of the signal of the other station from the signal that first arrives at each reference station in order to configure the system with a simpler configuration that does not require equipment The purpose of the present invention is to realize a position measuring system, a transmitting method, and a receiving method.

[0006]

In order to achieve the above object, the present invention provides (1)
In a position measuring system for measuring the position of an object to be measured in a specific region, the position measuring system has a transmitter that periodically and intermittently emits a pseudo-noise code signal uniquely assigned to the object to be measured. And a reference station installed in the same area, the reference station receives the pseudo noise signal from the measurement object, and a matched filter for the pseudo noise signal assigned to the measurement object. , A detector that obtains a correlated pulse signal from the output from the matched filter,
Among the correlation pulse signals obtained by the wave detector, a measuring means for measuring the arrival delay time of the signal detected by the other reference station with reference to the detection time of the signal detected first, Measuring the position of the body and the coordinates of the transmitter held by the object to be measured, and further (2) transmitting the signal of the pseudo noise code uniquely assigned to the object to be measured periodically and continuously. Having a machine,
(3) In the above (2), by using a delay locked loop instead of the matched filter, and detecting a specific signal sequence forming a pseudo noise signal emitted from the device under test,
2. A time difference between signals arriving at each reference station is measured, and further, (4) a transmitter for transmitting a pseudo-noise code signal uniquely assigned to the device under test periodically and intermittently. In the transmitter position measurement system described, it is necessary for the signal to propagate more than the period time of the pseudo-noise code, the reference station installed in the measurement area, and the difference between the longest distance and the minimum distance between the measured objects. The transmitter position measuring system according to claim 1, wherein a transmission time is a sum of a guard time, which is a different time, and (5) a pseudo noise signal is transmitted by the transmission method according to claim 4. In, the first signal has a function of measuring the guard time defined by the transmitter after the signal reaches one reference station, and further,
(6) The transmitter position measuring system according to claim 2 or 3, further comprising a transmitter that periodically and continuously transmits a pseudo-noise code signal uniquely assigned to the device under test.
A pseudo-noise code having a period of at least twice the guard time, which is the time required for a signal to propagate over a distance equal to or more than the difference between the longest distance and the minimum distance between the reference station installed in the measurement area and the measured object, The transmitter position measuring system according to claim 2 or 3, wherein a pseudo noise signal is transmitted by the transmission method according to claim 6, and the signal reaches the first reference station. It is necessary for the signal to propagate over the delay time of the received signal of each reference station measured based on the reference signal and the difference between the longest distance and the shortest distance between the reference station installed in the measurement area and the measured object. It has a function of comparing the guard time, which is the time, and measuring the difference, and when the delay time is greater than the guard time, a function of correcting it to the measured delay time minus the period of the pseudo noise signal. Specially to have It is obtained by the. Hereinafter, description will be given based on examples of the present invention.

FIG. 1 is a block diagram for explaining an embodiment of a transmitter position measuring system according to the present invention.
1d is a reference station, 2a to 2d are receiving systems, 3 is an object to be measured, 4 is a delay time measuring device, and 5 is a computer. The reference stations 1a to 1d are fixedly installed, for example, at four corners of the indoor ceiling, and the position coordinates of the receiving antennas 2a to 2d are known. In order to uniquely determine the coordinates of the DUT, the antennas of each station should not be on the same plane. The device under test 3, the reference transmitter, and the reference stations 1a to 1d are in line-of-sight with each other. Therefore, the carrier emitted from the device under test 3 and the reference station propagates in the line-of-sight and reaches each of the reference stations 1a to 1d. .. The transmission carrier of the pseudo noise signal may be radio wave, light, or sound wave, but in the embodiment described here, the radio wave is targeted. When the transmission carrier of the pseudo noise signal is light or a sound wave, for example, a converter for converting to an electric signal may be added.

Each of the reference stations 1a to 1d receives a signal continuously or intermittently transmitted from the device under test 3 and the reference oscillator, obtains a correlation wave output pulse, and transfers it to the delay time measuring device 4. .. The delay time measuring device 4 measures the delay time of the correlation pulse from each station on the basis of the correlation pulse input first, and transfers the result to the computer 5.
In the computer 5, the transferred delay time information and the coordinates (X ₁ , Y ₁ , Z ₁ ) of the reception position of each of the reference stations ₁ a to ₁ d
From (X ₄ , Y ₄ , Z ₄ ) the position coordinates (X,
Y, Z) is measured.

FIG. 2 is a block diagram of the transmitter held by the object to be measured and the receiver of each reference station in the transmitter position measuring system. In FIG. 2, 10 is a trigger signal generator and 11 is a pseudo noise (PN) signal. Generator, 12 is a frequency converter, 13 is an amplifier, 14 is a transmitting antenna, 15 is a receiving antenna, 16 is an amplifier, 17 is a frequency converter, 18 is a matched filter, 1
Reference numeral 9 is a detector. The object to be measured has a pseudo noise (PNm) signal generator 11 of a sequence peculiar to the object to be measured, and outputs the signal to a radio frequency (RF) band (for example, 800 MHz, 1 GHz).
Upconvert and send. The transmission is controlled by the trigger signal generator 10 and is transmitted every T time. At the reference station, the received RF band signal is down-converted, passed through the matched filter 18 matching the PN code specific to the DUT in the intermediate frequency (1F) band, and then passed through the envelope detector 19 to output the autocorrelation peak. To get The matched filter 18 can be generally realized by a SAW device or CCD. Further, instead of the matched filter 18, a convolver may be used for autocorrelation.

FIG. 3 is a diagram showing the correlation detection pulse output of each PN signal obtained by the receiver of each station. The period of the pseudo noise signal and the timing of trigger signal generation can be arbitrarily selected, but since a multipath signal is generated depending on the measurement environment, the signal generation time interval is only required to sufficiently attenuate the multipath signal. In the period 1 of FIG. 3, the reference station 1a first obtains the received signal, and then the reference stations 1b, 1d, 1c are sequentially received. At this time, if the delay time of the other station signal t _2, t _3, t ₄ the measurement from the signal received at the reference station 1a, the coordinates of the object to be measured (x, y, z) and the respective reference station coordinates (X The relationship between ₁ , Y ₁ , Z ₁ ) to (X ₄ , Y ₄ , Z ₄ ) is given by the following equation.

[0011]

[Equation 1]

However, c is the speed of light. The coordinates of the object to be measured are calculated by solving the above equation for (x, y, z). During the period 2 in FIG. 3, the measured object moved, so
The received signal is first obtained at the reference station 1b, and subsequently received at the reference stations 1c, 1a, 1d in this order. At this time, the delay time t of the signal of the other station from the signal received by the reference station 1b
_{If 3} , t ₁ and t ₄ are measured, the coordinates (x, y,
z) and the reference station coordinates (X ₁ , Y ₁ , Z ₁ ) to (X ₄ , Y ₄ ,
The relationship with Z ₄ ) is given by the following equation.

[0013]

[Equation 2]

By solving the above equation for (x, y, z),
The coordinates of the moving object to be moved are calculated.

FIG. 4 is a block diagram of a delay time measuring circuit for measuring t _{1 to} t _{4. In} the figure, 20a to 20d are waveform shapers, 21, 25 and 27 are OR circuits, and 22 is a flip-flop ( FF _0), 23 a to 23 d flip-flop (FF ₁ ~FF _4), 24 a NOR circuit, 26a to 26d
Is a counter and 28 is a clock signal generator. The waveform of the correlation detection pulse signal from each station is shaped. Signal S
_{Of the 1} (t) to S ₄ (t), the signal that reaches first is FF ₀ 2
2 is set and counters 26a to 26 for the respective channels
The CLR terminal of d becomes low, and clock counting is started. Next, when the signal of each channel arrives, the FF ₁ 23a to FF ₄ 23d for each channel are reset, the ENABLE signal becomes low, each counter stops, and the count number C ₁ of the clock pulse at that time, C ₂ , C ₃ and C ₄ are output to the computer. When all the signals of four channels arrive, the FF ₀ 22 is reset and each counter is cleared, and the state is ready for the next measurement. It is possible that multipath fading occurs depending on the measurement environment and signals of sufficient level for measurement do not arrive at all reference stations. At this time, the carry signal (CRY) indicating the delay time is taken out from the counter so that the FF ₀ 22 can be reset even with this signal.

Since the counter is not active in the counter of the channel where the signal first arrives, the count number is 0. In the computer, the number of clocks and the number of counts C ₁ ,
The delay time is calculated from C ₂ , C ₃ and C ₄ . The determination of the channel where the signal first arrived may be made by examining the channel whose count number is 0. In the case of the period 1 in FIG. 3, C ₁ = 0 because S ₁ (t) arrives first, and t _{2 to} t ₄ are C ₂ to C.
Obtained from ₄ . In this case, the measurement accuracy depends on the speed and stability of the clock and the measurement environment. From these delay times and the coordinates of each reference station, the coordinates of the object to be measured are measured using the above-mentioned formula.

FIG. 5 is another configuration diagram of the transmitter held by the object to be measured and the receiver of each reference station in the transmitter position measuring system, in which 30 is a pseudo noise (PN) signal generator, 3
1 is a frequency converter, 32 is an amplifier, 33 is a transmitting antenna, 34 is a receiving antenna, 35 is an amplifier, 36 is a frequency converter, 37 is a matched filter, and 38 is a wave detector. In the embodiment shown in FIG. 2, the signal from the device under test is generated intermittently, and the transmitter needs a trigger generator. However, in the embodiment shown in FIG. You don't need a vessel. Other operations are the same as those in FIG.

FIG. 6 is a further configuration diagram of the transmitter held by the object to be measured and the receiver of each reference station in the transmitter position measuring system. In the figure, 39 is a delay locked loop and 40 is a signal train discriminator. In addition, other parts having the same operations as those in FIG. 5 are denoted by the same reference numerals. The system according to any one of claims 1 and 2, wherein the matched filter and the detector are replaced by a delay lock loop 39 and a signal sequence determiner 40. The delay lock loop 39 is a synchronizing circuit that follows the phase of the received PN signal. Further, the signal train determiner 40 outputs a signal when a specific signal train of the PN signal being followed is input. Delay lock loop 39 and signal train decision unit 40
Can be realized by the configuration as shown in FIG.

FIG. 7 is a diagram showing a delay lock loop and a signal sequence deciding unit, in which 41 is a cross-correlation network and 4 is a
2 is a loop filter, 43 is a voltage control clock, 44 is a 7-stage feedback shift register, 45 is an EXOR (exclusive OR) circuit, and 46 is an AND circuit. 127 chips P
It is composed of a 1Δ-type delay lock loop that follows the N signal and a signal sequence determiner realized by inputting the output from each stage of the 7-stage feedback shift register 44 that generates the reference PN signal to the AND gate 46. It is a reception timing output circuit. In this case, since there is only one set of "1111111" in the PN signal of 127 chips, the delay time difference between the reference stations is measured by generating the reception timing output when this signal sequence comes in. Will be. The coordinates of the object to be measured can be calculated in the same manner as the other two systems.

As described above, according to the present invention, intermittent position tracking of the object to be measured can be realized by a simple system which does not require a reference transmitter. Further, the measurement error due to the delay time at the time of transmitting the reception timing output signal from each base station is small, which is effective for a system using sound waves. In the embodiment of the present invention, the number of measured objects is one.
In the system shown in FIG. 3 as well, a plurality of different series of PN codes are used, and a plurality of matched filters or DLLs corresponding to them are prepared in the reference station, whereby the positions of a plurality of measured objects can be tracked.

In the above-described embodiment, when the delay time in the connection cable between the computer and each reference station does not cause a problem, a reference transmitter, a clock, or other device that indicates the time reference is not required, and the operation is simpler. In order to configure the system with the configuration, we have proposed a transmitter position measurement system that calculates the coordinates of the measured object by measuring the delay time of the signal of the other station from the signal that first arrives at each reference station. When this transmitter position measuring system is used in an actual environment, the carrier of the transmission signal from the measured object such as radio waves, light (such as infrared rays), and sound waves may be blocked by obstacles. In this case, it was not clear how long to wait for the arrival of the received signal. In addition, when a continuous transmission signal is used, for example, when the signal to be received first serving as a reference for measuring the delay time of each received signal is lost due to the above-mentioned reason, the signal arriving second is determined as Since the delay time is measured on the basis, the delay time of the signal that should arrive first may be erroneously measured, resulting in a large error in the position estimation. In such a case, it is preferable to use the following embodiment. That is, in claims 4 and 6, a method of transmitting a pseudo noise signal emitted from the device under test is proposed, and in claims 5 and 7, claims 4 and 6 are proposed.
Has proposed a method of receiving a signal emitted by the above transmission method.

FIG. 8 shows a transmission signal waveform for explaining the transmission method according to the fourth aspect. Period T peculiar to the measured object
A guard time Tg is provided after transmitting the pseudo noise signal of. Here, the guard time Tg is Tg = (Lmax-Lmin) / c (c: carrier propagation speed, where Lmax is the maximum distance between the reference station and the measured object in the area to be measured, and Lmin is the minimum distance. ). Although Lmax and Lmin differ depending on the environment to be measured, for example, in the case where the reference stations 52a to 52d are installed as shown in FIG. 9 inside the cube indoor 51 and the measured object 53 is on the bottom surface, as shown in FIG. Then, the length of the diagonal line should be selected as Lmax, and the minimum distance between the bottom surface and the reference station should be selected as Lmin. In order to generate the signal of FIG. 8, the trigger signal generator shown in the transmitter embodiment of the transmitter position measuring system according to claim 1 (FIG. 2) may be designed for the target measurement area. .. An example thereof is shown in FIG.

FIG. 10 uses a 7-bit feedback shift register to control a 127-chip M-sequence code generator of a feedback tap (3, 7) by a trigger circuit composed of a counter and a flip-flop. In the figure, 61 is an OR circuit, 6
2 is a flip-flop (FF1), 63 is a counter,
Reference numeral 64 is a flip-flop (FF2), 65 is a clock signal generator, 66 is an OR circuit, 67 and 68 are AND circuits, 69 is a shift register, and 70 is an EX-OR circuit.

At the same time that FF1 and FF2 are reset by the reset signal, the shift register 69 is loaded with the initial value (1111111). F when reset signal is input
Since the output of F2 is Low, the clock signal is not input to the shift register 69, and the value of the shift register 69 is maintained at (1111111). Therefore, the output of FF1 becomes Hi, and the counter 63 starts counting clocks. When the count Cg corresponding to the guard time Tg is generated as a carry, the output of FF2 becomes Hi and the generation of the pseudo noise signal is started. When the signal is generated for one cycle, the signal train in the register returns to the initial value (1111111) again, and the AND gate output becomes Hi again, so that the generation of the pseudo noise signal is stopped and the guard time is measured. Obviously, in this way, the signal of FIG. 8 can be generated.

By the way, since the guard time Tg of the signal is larger than the maximum value of the delay time that can be measured by the delay time measuring device, the signal of FIG. 8 is used to measure the time after the first signal is received by the receiver. , If the signals are not received by some reference stations even if the time exceeds Tg, it can be considered that the signals to be received by those stations are lost.
The delay time measuring device can be reset and the signal measurement of the next cycle can be started. The receiving method according to claim 5 satisfying such a function is realized by using the delay time measuring device shown in the embodiment of FIG.

FIG. 11 is a diagram showing an embodiment of a delay time measuring device for realizing the receiving method according to the fifth aspect. 7 in the figure
1a to 71d are waveform shapers, 72 is an OR circuit, 73a to
Reference numerals 73d and 74 are flip-flops, 75a to 75e are counters, and 76 is a clock signal generator. The roles of the counters 1 to 4 and the FFs 1 to 4 are the same as those in FIG. The earliest signal among the signals arriving at the reference station is FF
The output of 5 becomes Hi, and all counters start time measurement. The counter 5 counts the number of clocks corresponding to the guard time and generates a carry signal. The output of FF5 becomes Low, each counter stops counting, and each count number at that time is used as the delay time for position measurement of the measured object. When the transmission signal is generated periodically and continuously as in the receiver position measuring system according to claims 2 and 3, the pseudo noise signal generation control by the trigger circuit is not performed. It is necessary to select the period of the noise signal according to the target measurement environment. Letting T be the period of the pseudo noise signal to be selected, T ≧ 2 · Tg is selected. As an example, considering the case where a sound wave is used as a carrier (sound velocity is 300 m / s), the chip rate of the pseudo noise signal is 6 kHz, and (Lmax-Lmin) = 20 m, the required number N of chips of the pseudo noise signal is considered. N ≧ (20/30) · 6000 = 400 When using the M-sequence code as the pseudo noise code, for example,
The code of 511 chips can be used. The pseudo noise signal generator for generating this code can be realized by using a feedback shift register as shown in FIG. 12, for example. 81 in the figure
Is an EX-OR circuit, and 82a to 82i are flip-flops.

In FIG. 13, the period T of the pseudo noise signal is 2.multidot.T.
An example of the detection signal from each reference station when g is shown. Each pulse signal is a signal whose waveform has been shaped by the delay time measuring device. In this example, after the signal is transmitted from the device under test, the reference station 1 closest to the device under test loses the signal to be received. At this time, the first detected signal is
Since it is the signal of the reference station 2, the delay time of signal detection of another station is measured with this signal as a reference. Claim 3
In the measuring methods of 4 and 4, since the delay time in the reference station 1 is measured as t ₁ , the delay time in the reference station 1 closest to the measured object is measured most, and a large error occurs in the position calculation of the measured object. Occurs.

Here, when the time difference t ₀ between the missing signal that should have been detected by the reference station 1 (indicated by a dotted line) and the detection pulse signal of the reference station 2 that has become the time reference of the delay time measurement is Tg at maximum. Can be considered. Further, since the signal of the next cycle detected by the reference station ₁ must be measured as t ₁ > Tg, the maximum value of (t ₀ + t ₁ ) is 2 · Tg. Therefore, the period of the pseudo noise signal is set to T ≧ 2 · Tg, the measured delay time is compared with Tg, and when t ≧ Tg, (t−T) is set as the delay time, so that the signal is lost. When it does, the correct delay time is measured (Claim 7).

FIG. 14 is a diagram showing a delay time measuring device which is an embodiment of the receiving method according to the present invention. In the figure, 91a
To 91d are waveform shapers, 92 is an OR circuit, and 93a to 93.
Reference numerals d and 94 are flip-flops, 95a to 95e are counters, 96a to 96d are count number comparing and correcting units, and 97 is a clock signal generator. The operation principle of the circuit is the same as that of FIG. 11 except for the counter 5 and the count number comparison and correction unit. In FIG. 14, the counter 5 counts the number of clocks corresponding to the period of the pseudo noise signal to generate a carry signal. Therefore, the counters 1 to 4 that measure the delay time for each cycle of the pseudo noise signal are reset. The count number comparison / correction unit compares the counter output value Ci (C _{1 to} C ₄ ) at each station with the count number Cmax of the clock corresponding to the maximum delay time Tg. As shown in FIG. 15, when Ci is smaller than Cmax, Ci is used for position calculation as it is, but when it is larger than Cmax, it is set as Ci (C
i- _CT ) is used. Here, C _T is the number of clocks corresponding to the period T of the pseudo noise signal, and in the example of FIG. 13, C _T =
2. Cmax. The clock frequency is constant and Cm
Since ax is fixed in the target area and C _T is also fixed in the system, the function of the count number comparison / correction unit can be realized by the software of the computer (see FIG. 1) that actually calculates the position.

[0030]

[Effect] As is apparent from the above description, the present invention has the following effects. (1) Effect on claim 1: An object to be measured is made to hold a transmitter of a pseudo noise signal, the pseudo noise signal is intermittently transmitted, the signal is received by a plurality of reference stations, and the pseudo noise signal sequence is formed. By obtaining the correlated pulse signal using the corresponding matched filter and finding the relative arrival delay time of each received signal, the position of the measured object can be intermittently measured by a simple system that does not use a reference transmitter or a synchronization circuit. Coordinates can be tracked. (2) Effect on claim 2: The device under test holds the transmitter of the pseudo noise signal, continuously transmits the pseudo noise signal, and the signals are received by a plurality of reference stations to form a sequence of the pseudo noise signal. By obtaining the correlated pulse signal using the corresponding matched filter and finding the relative arrival delay time of each received signal, the position of the measured object can be intermittently measured by a simple system that does not use a reference transmitter or a synchronization circuit. Coordinates can be tracked. (3) Effect on claim 3: The device under test holds a transmitter of a pseudo noise signal, continuously transmits the pseudo noise signal, the plurality of reference stations receive the signal, and synchronously follow the pseudo noise signal. By using the delay lock loop to obtain the relative arrival delay time of each received signal, it becomes possible to intermittently track the position coordinates of the measured object with a simple system that does not use the reference transmitting station. (4) Effect on claim 4: In a system for measuring the position of a transmitter that intermittently emits a pseudo noise signal, if a received signal is missing at some reference stations, the signal to be received at the reference station is missed. Can generate no signal. (5) Effect on claim 5: In the system for measuring the position of a transmitter that intermittently emits a pseudo noise signal by the method of claim 4, even if a received signal is lost at some reference stations, the next transmission is performed. The measurement of the signal delay time can be started accurately. (6) Effect on Claim 6: In a system for measuring the position of a transmitter that continuously emits a pseudo noise signal, a signal that can determine whether or not a signal is missing can be generated at the time of reception at a reference station. (7) Effect on claim 7: In a system for measuring the position of a transmitter that continuously emits a pseudo noise signal by the method of claim 6, when a received signal is missing at some reference stations, an error due to the missing is generated. It is possible to measure the delay time of the transmission signal without the occurrence.

[Brief description of drawings]

FIG. 1 is a configuration diagram for explaining an embodiment of a transmitter position measuring system according to the present invention.

FIG. 2 is a configuration diagram of a transmitter held by a measured object and a receiver of each reference station in the transmitter position measuring system.

FIG. 3 is a diagram showing a correlation detection pulse output of each PN signal obtained by a receiver of each station.

FIG. 4 is a diagram showing a delay time measuring circuit.

FIG. 5 is another configuration diagram of the transmitter held by the measured object and the receiver of each reference station in the transmitter position measuring system.

FIG. 6 is still another configuration diagram of the transmitter held by the measured object and the receiver of each reference station in the transmitter position measuring system.

FIG. 7 is a diagram showing a delay lock loop and a signal sequence determiner.

FIG. 8 is a diagram showing a transmission signal waveform.

FIG. 9 is a diagram showing a reference station and an object to be measured (fixed liner) installed indoors.

FIG. 10 is a diagram showing a trigger signal generator.

FIG. 11 is a diagram showing a delay time meter measuring device.

FIG. 12 is a diagram showing a feedback shift register.

FIG. 13 is a diagram showing an example of a detection signal from each reference station.

FIG. 14 is a diagram showing another delay time measuring device.

FIG. 15 is a diagram showing a flowchart of position calculation based on count output.

[Explanation of symbols]

1a to 1d ... Reference station, 2a to 2d ... Receiving system, 3 ...
Object to be measured, 4 ... Delay time measuring device, 5 ... Calculator.

Claims (7)

[Claims] 1. A position measuring system for measuring the position of an object to be measured in a specific region, wherein the position measuring system periodically and intermittently emits a signal of a pseudo noise code uniquely assigned to the object to be measured. And a reference station installed in the same area, the reference station receives a pseudo noise signal from the measurement object, and the pseudo noise assigned to the measurement object. A matched filter related to the signal, a detector that obtains a correlation pulse signal from the output from the matched filter, and a correlation pulse signal obtained by the detector, based on the detection time of the first detected signal, other A transmitter position measuring system characterized by having a measuring means for measuring the arrival delay time of a signal detected at the reference station, and measuring the position of the measured object and the coordinates of the transmitter held by the measured object. Stem. 2. The transmitter position measuring system according to claim 1, wherein the device under test has a transmitter which periodically and continuously transmits a signal of a pseudo noise code uniquely assigned to the device under test. 3. A delay lock loop is used in place of the matched filter to detect a specific signal sequence forming a pseudo noise signal emitted from the device under test to measure the time difference between the signals reaching each reference station. The transmitter position measuring system according to claim 2, wherein 4. The transmitter position measuring system according to claim 1, further comprising a transmitter for periodically and intermittently transmitting a signal of a pseudo noise code uniquely assigned to the device under test. Transmission time is the sum of the time and the reference station installed in the measurement area and the guard time, which is the time required for the signal to propagate over the difference between the longest distance and the minimum distance between the measured objects. And a transmission method characterized by the following. 5. The transmitter position measuring system according to claim 1, wherein a pseudo-noise signal is transmitted by the transmission method according to claim 4, and after the first signal reaches one reference station, the transmitter position is determined by the transmitter. A receiving method characterized by having a function of measuring a specified guard time. 6. The transmitter position measuring system according to claim 2, further comprising a transmitter that periodically and continuously transmits a signal of a pseudo noise code uniquely assigned to the device under test. Pseudo-noise code with a period of more than twice the guard time, which is the time required for the signal to propagate over the distance between the maximum distance and the minimum distance between the reference station installed in A transmission method characterized by using. 7. The transmitter position measuring system according to claim 2 or 3, wherein a pseudo noise signal is transmitted by the transmission method according to claim 6, wherein the signal first reaching one of the reference stations is measured as a reference. And the delay time of the received signal of each reference station, the reference station installed in the measurement area-the guard time, which is the time required for the signal to propagate over the distance between the longest distance and the shortest distance between the measured object and And has a function of measuring the difference, and when the delay time is longer than the guard time, it has a function of correcting the measured delay time by subtracting the period of the pseudo noise signal. How to receive.