JP3991081B2 - Active tag device - Google Patents

Description

In an active tag system using ultrasonic waves, radio waves, or light waves, the present invention receives an ultrasonic signal, a high-frequency signal, or an optical signal transmitted from a transmitting means using a plurality of directional antennas or transducers. Alternatively, an ultrasonic signal, a high frequency signal or an optical signal transmitted by switching a plurality of directional antennas or transducers in the transmitting means is received by the receiving means, and the plurality of directional antennas or transducers are switched. Alternatively, by measuring the timing, amplitude, frequency, or phase of the ultrasonic signal, high-frequency signal, or optical signal received by the receiving means when the combination is changed, the position where the transmitting means exists, the direction, distance, or position where the transmitting means exists Or the combination of these is high It relates Akuteibu tag devices capable of sensing in degrees.

As a direction detector, there has been a circulation switching type Doppler direction detector as a method for detecting the direction of arrival of radio waves by switching a plurality of antennas, and recently, switching a plurality of antennas as shown in Patent Document 1. Alternatively, there are some which perform digital processing by converting into a digital signal by an A / D converter as shown in Patent Document 2. On the other hand, as a radar apparatus for measuring the azimuth, there is a three-dimensional radar disclosed in Patent Document 1, or a method of performing horizontal and vertical azimuth identification in a time-sharing manner by providing an antenna combining distributor as in Patent Document 2. Or 76 GHz band automotive millimeter wave radar of Non-Patent Document 2 has a method of measuring the horizontal direction by changing the combination of the directivity of a plurality of transmitting side directional antennas and receiving side directional antennas. .

In a conventional Doppler direction detector, a low-frequency signal synchronized with switching scanning is extracted from the Doppler effect generated by sequentially circulating and switching a plurality of antennas arranged on the circumference, and the arrival direction of the received signal from the phase of the low-frequency signal The size of the receiving antenna and the entire device increased, and high-frequency signals with a high frequency of several hundreds of megahertz or higher, radio waves transmitted continuously or in bursts, and spectrum-spread radio waves were transmitted. It is difficult or almost impossible to detect the direction.
On the other hand, in a recent direction finder, if a plurality of antennas are switched as in Patent Document 1, the phase difference must be measured at a high speed. Therefore, if an analog type phase detector is not used, the processing becomes slow. When the phase difference is calculated by converting it into a digital signal as shown in 2, there is a problem that only the method of combining the antennas can be taken because a time delay occurs when processing is performed by switching a plurality of antennas. On the other hand, in the system of FIG. 4 according to the embodiment of the present invention, even when a plurality of antennas are switched and converted into a digital signal for processing, if digital signal processing is performed using the high-frequency logic circuit disclosed in Patent Document 8, real-time processing is performed. Can be processed.
The three-dimensional radar of Patent Document 3 has the disadvantage that it is large, complicated and expensive, and the radar apparatus of Patent Document 4 acquires amplitude information and phase information necessary for detection and azimuth measurement by combining and distributing the transmitting and receiving antennas. When processing, it is difficult to perform real-time processing if converted to digital signal, so the difference between multiple antenna outputs is taken when acquiring phase information, so the output is the lowest at the center of the azimuth and sufficient output However, in FIG. 4 of the embodiment of the present invention, when switching between a plurality of antennas or transducers, individual antennas or transducers or antennas are used. Alternatively, for each transmitter / receiver combination, it is converted into a digital signal, phase vectors are detected, and real-time processing is performed, so the phase is particularly large at the center of the direction The accuracy of the measurement is high.
The 76 GHz band automotive millimeter-wave radar of Non-Patent Document 4 requires real-time processing to prevent a collision and cannot be processed by converting it to a digital signal, so the beam is extremely narrowed to measure the direction. In addition, since the directivity directions of a plurality of transmission antennas and reception antennas are combined, it is difficult to make the combination fine, and the accuracy is about ± 4 °. 4 can achieve an accuracy of ± 1 °.
In the underwater ultrasonic devices of Patent Documents 5 to 7, this must be carried out separately for scanning detection for measuring the direction in which an obstacle or reflector is located and for depth measurement for measuring the depth. In FIG. 1 of the embodiment of the invention, both scanning detection and depth detection for measuring depth can be performed simultaneously.
Special table 2002-529942 gazette JP 09-236646 A JP 2001-42036 A Japanese Patent Laid-Open No. 11-174147 Japanese Patent Laid-Open No. 05-232225 Japanese Patent Laid-Open No. 05-288851 JP 2001-141808 A Japanese Patent Application No. 2004-057508 Kazumi Sakamaki "Digital signal processing that can be seen" published Masaru OGAWA "ELECTRICALLY SCANNED MILLIMETER WAVE AUTOMOTIVE RADAR" MWE2003 Microwave Workshop Digest, [WS4-2], P105-P109, November 26-28, 2003

The conventional device for detecting the direction is used stationary or semi-fixed, and the delay in processing for detecting the direction is allowed. Therefore, the antenna and the detection device are large, and the processing is performed in real time in a short time. Therefore, there is a problem that it is difficult to use the mobile phone as a pedestrian or a robot as it is or to carry it while carrying it as it is. In addition, in conventional collision prevention devices equipped in automobiles, it is necessary to extremely narrow the directional beam of the antenna, and the direction detection accuracy is limited by the limit value of the beam width that can be formed, or a plurality of receivers are provided. Further, since the phase difference of the spread spectrum code is detected, there are problems such as low detection accuracy.

The active tag device according to the present invention has been made to solve the above-described problems, and the transmitting means and the receiving means can be miniaturized. The transmitting means or the receiving means can include a plurality of directional antennas or transmission / reception devices. Detects at least the frequency and / or phase of the ultrasonic signal, high-frequency signal, optical carrier signal or sub-carrier signal received when switching or changing the wave generator in real time in a short time without any processing time delay it is thereby possible to detect the direction in which the transmitting means is toward the direction or the mobile body located, in a short time and distance between said transmitting means and receiving means with high accuracy in real time.

In the active tag device according to the present invention, the transmitting means and the receiving means can be reduced in size and weight, and can be attached to or carried by the moving body. From the transmitting means, an ultrasonic signal, a high-frequency signal, or an optical signal can be obtained. A signal is transmitted while periodically switching a plurality of antennas or a plurality of transducers arranged at intervals of one wavelength or less of the ultrasonic signal, the high-frequency signal, or the carrier signal or subcarrier signal of the optical signal, and the receiving means The direction in which the transmitting means is located by measuring the phase difference of the carrier signal or subcarrier signal in real time in a short time with an accuracy within ± 1 ° corresponding to the plurality of antennas or the plurality of transducers Alternatively, the direction in which the moving body is heading and the distance between the transmitting means and the receiving means can be determined with high accuracy in a short time. It can be detected in real time.

The active tag device according to the present invention comprises transmitting means and receiving means for transmitting and receiving an ultrasonic signal, a high-frequency signal or an optical signal, and is modulated by an identification code and a measurement code in the transmitting means or is subjected to spectrum spreading. A plurality of antennas or a plurality of transmitting a sound wave signal, a high-frequency signal or an optical signal, and the transmitting means or the receiving means or both of them are arranged at intervals of one wavelength or less of the carrier signal or subcarrier signal of the measurement signal And a switching synthesizer for periodically switching and / or changing the combination of the plurality of antennas or the plurality of transducers, or on a road surface, a sidewalk, a streetlight pole, a utility pole, a traffic signal or It is fixed to the ceiling or wall, etc. The transmitting means or the receiving means or both of them are carried or worn by a moving body such as a person or a robot, and in the receiving means, the transmitting means is identified by the identification code, and the measuring code is used. the direction in which direction or the moving object to which the transmitting means is located is towards detects in real time in a short time and distance between said transmitting means and receiving means with high accuracy.

An embodiment of the present invention will be described below with reference to FIG. In FIG. 1, 1 is a transmission means, 2 is a reception means, 21a and 21b are directional antennas, 31 is a directivity pattern of the antenna of the transmission means 1, and 31a and 31b are antennas 21a of the reception means 2 from the transmission means 1. Direction lines toward 21b, 32a and 32b are directivity patterns of antennas 21a and 21b, 33a is an extension line of directivity 31, 33b is a center line of directivity 32a and 32b, and 34a, 34b, 34c and 34d are dimension lines It is.
Here, 34a is dm, and 34b is Dm. A high-frequency signal spread by a spread spectrum code in the direction of directivity 31 is radiated from the transmitting means 1, and the receiving means 2 periodically switches between the antennas 21a and 21b having directivity 32a and 32b. Is received.
In order to detect the direction in which the transmission means 1 is located when viewed from the reception means 2, the spread code of the high frequency signal propagated from the transmission means 1 through the direction lines 31a and 31b or the propagation phase difference of the carrier wave is measured. The propagation phase difference Δφ is obtained from Δφ = (2π / λ) {r × (d / D)}. Here, rm = the length between the antennas 21a and 21b, dm = 34a, Dm = 34b, and dm << Dm.
First, when the case where the propagation phase difference Δφ is measured by the phase difference of the carrier wave of the high-frequency signal is considered, assuming that the radio frequency is in the 2.4 GHz band, λ = 0.125 m, r = 0.03 m, d = 0. If 1 m and D = 10 m, then Δφ = 50.24 {0.03 × (0.1 / 10)} = 0.015 radians = 0.9 °. Since the measurement accuracy of the propagation phase difference Δφ of the carrier wave can be realized as 1 / 100th of π / 4 radians, that is, ± 0.008 radians = ± 0.45 °, the measurement accuracy is about ± 3 cm after 10 m. . That is, when the distance between the antennas 21a and 21b is 3 cm, the position of the transmitting means 10 m ahead can be detected with an accuracy of ± 3 cm. Next, considering the case where the propagation phase difference Δφ is measured by the phase difference of the spreading code, if the propagation speed of the spreading code is 4 Mbps, λ = 75 m, and r = 0.4 m, d = 1 m, and D = 10 m. Then, Δφ = 0.084 {0.4 × (1/10)} = 0.0036 radians = 0.2 °. The measurement accuracy of the propagation phase difference Δφ of the spread code is slightly better than measuring the phase difference of the carrier wave, and ± 0.006 radians = ± 0.34 ° can be realized, so the measurement accuracy is about ± 45 cm after 10 m. Become. That is, when the distance between the antennas 21a and 21b is 40 cm, the position of the transmitting means 10 m ahead can be detected with an accuracy of ± 45 cm.
The above case is an ideal case in which the influence of surrounding reflectors is not considered, but actually the measurement accuracy deteriorates due to the influence of reflectors. As a countermeasure, the influence of the reflector can be reduced by using circularly polarized directional antennas on the transmitting means 1 and transmitting means 2 sides, and the phase difference is measured at a high speed of 1 ms / time and the moving average of 100 times is taken. As a result, the measurement accuracy can be increased by a factor of 10 to ± 0.045 °.
Further, assuming that the antenna directivity direction 33a of the transmitting means 1 is along the sidewalk, by detecting a deviation dm from the sidewalk, it is possible to output an alarm that the vehicle is off the sidewalk and correct the walking direction.
Also, it controls the rough direction by measuring the phase difference of the spread spectrum code, complements each other by controlling the precise direction by measuring the phase difference of the carrier wave, or geomagnetic sensor or acceleration sensor The accuracy of direction or position detection can be improved by measuring the absolute azimuth or accumulating the movement distance using the above as an auxiliary.
As another method for detecting the distance, a plurality of carriers, a plurality of subcarriers, or a plurality of modulations that are hopped, synchronized, or orthogonal between a plurality of carrier frequencies that are synchronized or orthogonal in the transmitting means 1 can be used. Generate a plurality of high-frequency signals with different frequencies by a signal or a combination thereof, or perform amplitude modulation, double sideband modulation, single sideband modulation or orthogonal frequency division multiplexing with an arbitrary signal to generate a plurality of high-frequency signals with different frequencies Generated and transmitted simultaneously or alternately, and the receiving means 2 detects the phase difference between the high-frequency signals of the plurality of different frequencies, thereby detecting the distance Dm between the transmitting means 1 and the receiving means 2 from the reception timing. Can be detected with much higher accuracy.
For example, the phase of the carrier wave of the high frequency signal hopped from f0 to (f0 + Δf) of the high frequency signal transmitted from the transmitting unit 1 and received by the receiving unit 2 is the propagation speed of the radio wave C (m / s) Then, S1 = ASin {2πf0t + φ0 + 2πD / (C / f0)}, S2 = BSin {2π (f0 + Δf) t + φ0 + 2πD / (C / (f0 + Δf))}. When the phases of S1 and S2 are detected, Φ1 = {φ0 + 2πD / (C / f0)} and Φ2 = {φ0 + 2πD / (C / (f0 + Δf))}, so Φ2−Φ1 = 2πD {1 / (C / ( f0−Δf)) − 1 / (C / f0)} = 2πD {((f0 + Δf) / C) − (f0 / C)} = 2πD (Δf / C), and the phase difference (Φ2−Φ1) is detected. Thus, the distance D becomes D = (Φ2−Φ1) / {2π (Δf / C)}. When hopping 0.833 MHz, a phase difference of 1 ° is generated per 1 m, and a phase difference of 360 ° is generated. Thus, a distance of about 360 m can be detected.
Therefore, if the measurement accuracy of the phase difference can be improved to ± 0.03 °, a long scale (100 m unit or the like) is obtained using the spread spectrum code generated by the transmission means, and a short scale is obtained by hopping by the transmission means. The distance up to 100 m can be detected in 1 cm units with the same feeling as a normal tape measure. The distance exceeding 100 m can be further extended in units of 100 m using the spread spectrum code.
Instead of hopping the frequency from f0 to (f0 + Δf), a plurality of synchronized or orthogonal high-frequency signals are transmitted simultaneously or alternately, and the phase difference between the high-frequency signals is detected on the receiving means side. However, the same effect can be obtained.
Further, instead of switching by connecting a plurality of antennas to the receiving means 2, switching is performed by connecting a plurality of antennas to the transmitting means 1 or a high frequency signal spread by a different spread spectrum code for each of the plurality of antennas is used. The same effect can be obtained even if the signal is transmitted and received by the receiving means 1 using a single antenna.
Further, in the transmission means 1, transmission is performed by changing the transmission rate of the spread spectrum code for spreading the high-frequency signal, or the transmission means 1 is spread and transmitted simultaneously with a plurality of spread spectrum codes having different transmission rates and code sequences. The distance between the transmission means 1 and the reception means 2 can be measured by detecting and comparing the timing, amplitude, frequency, phase, or combination thereof of the plurality of spread spectrum codes in real time in a short time.
The antenna of the transmitting means 1 can play the role of the transmitting means 1 in all routes toward the intersection by making it non-directional when there are few reflecting objects around the intersection or the like. If there are many objects, connect multiple units with directivity and change the direction of directivity to match each with the direction of the sidewalk or pedestrian crossing or change the spreading code for each set of multiple antennas or identification number By changing the above, one transmission means 1 can guide a person along a plurality of sidewalks or pedestrian crossings along the road.
Further, since the receiving means 2 is a portable terminal, the identification number sent from the sending means 1 can be detected, and by knowing the position information of the sending means 1, it is possible to confirm the current position and the traveling direction. The portable terminal can provide a pedestrian guidance system that is effective for both visually impaired and healthy persons. On the other hand, a person carrying the transmission means 1 and fixing the reception means 2 can detect the exact position of the person carrying the transmission means 1.
Further, by fixing the transmitting unit 1 and the receiving unit 2 and monitoring the change in the phase difference of the high-frequency signal, it can be detected that a moving object such as a person exists between the transmitting unit 1 and the receiving unit 2. .
Also, a plurality of sets of directional antennas 21a and 21b of the receiving means 2 are prepared and arranged on a diagonal line, and each direction of the plurality of sets is switched to measure the direction and distance in which the transmitting means 1 exists, and the result is The transmission means 1 can be tracked or tracked.
In addition, the transmitting unit 1 is always in a standby state, and the radio frequency signal is transmitted continuously or in bursts in response to a request by the radio signal from the receiving unit 2, thereby effectively using radio waves and reducing power consumption. Can be planned. For this purpose, it is effective to employ a 2.4 GHz band spread spectrum communication system.
In addition, a so-called multipath direction measurement error caused by interference between a high-frequency signal transmitted from the transmitting unit 1 and directly propagated to the receiving unit and a high-frequency signal reflected and propagated on the ground or the side wall is caused by spread spectrum communication. It has been confirmed that the influence can be reduced by adopting the method, adopting a circularly polarized directional antenna for the directional antenna, and providing a plurality of circularly polarized directional antennas for the transmitting means or the receiving means. .
In addition, the antennas 21a and 21b of the receiving means 2 are set as a plurality of directional antennas, and the direction of the directivity is set to be substantially the same and set at an interval shorter than the wavelength of the carrier wave. Multipath generation direction by installing at intervals shorter than the chip length, or by arranging the antennas along a circular shape, square shape, or arbitrary shape at intervals shorter than the wavelength of the carrier wave while gradually changing the directivity of multiple antennas It has also been confirmed that multipath effects can be reduced by analyzing
In addition, when there is a reflecting object in or around the high-frequency signal propagation path from the transmitting means 1 to the receiving means 2, a coating material, a plate material, a film material or the like having an attenuation characteristic is applied, adhered or attached. Multipath effects can be reduced. When a circularly polarized directional antenna is used as the antenna of the transmitting means 1 and the receiving means 2, there is a reflecting object around the propagation path from the transmitting means to the receiving means, in the propagation path, or along the propagation path. In this case, the first reflection caused by the reflecting object is attenuated because the polarization plane is different, but the second reflection is returned to the original polarization plane, but there is a disadvantage that the attenuation is reduced. If a countermeasure is taken, there is an advantage that double reflection (for example, 2 × 3 = 6 dB attenuation increase as 3 dB increase in attenuation per time) can be obtained by two reflections.
The directivity of the plurality of antennas connected to the transmitting means 1 is directed along a specific path or direction, or a leaky coaxial cable having a plurality of radiating elements is installed along the specific path or direction. The frequency of the carrier wave of the high frequency signal transmitted from the plurality of antennas or the leaky coaxial cable is the same or held within a certain error, and the high frequency signal is transmitted from the plurality of antennas or the leaky coaxial cable. The timing is switched alternately or sequentially along a specific direction and used to guide the traveling direction of a pedestrian, a moving object or a flying object.
In addition, a plurality of sets of leaky coaxial cables in which the antenna or the opening surface of the transmitting unit 1 is continuously provided at half-wavelength intervals of the carrier wave are provided, and the high frequency signal transmitted from the transmitting unit differs depending on the group, for example Whether the current location or area of the transmitting means is a safe zone by detecting the direction in which the high-frequency signal is transmitted from the receiving means for each set, with codes or signals indicating safety zones and dangerous zones superimposed. It can be detected whether it is in a danger zone.
Also, as the antenna of the transmitting means 1, two leaky coaxial cables are installed in parallel along the boundary between the safety zone and the danger zone such as the end of the station platform, and a safety signal is sent to one cable to the other cable. By sending a signal, the visually impaired can detect and identify the end of the station platform or the safety zone and the danger zone, or use a directional antenna to send a safety signal along the center of the pedestrian crossing. It is possible to cross without crossing the pedestrian crossing by sending a danger signal along both ends.
Further, the transmitting means 1 and the receiving means 2 are mounted on or attached to the same mobile body or carried by the mobile body, the antenna of the transmitting means 1 is a circularly polarized directivity antenna, and the antenna of the receiving means 2 is The transmitting means 1 is a circularly polarized directional antenna of reverse rotation, and the high frequency signal transmitted from the transmitting means 1 is reflected from a reflecting object existing around the moving body and received by the receiving means. When the reception means 2 is obstructed, the spreading code of the high-frequency signal transmitted from the transmission means 1 is changed to change the amplitude of the high-frequency signal. Alternatively, an obstacle in the direction in which the moving body travels can be detected by measuring the frequency, the phase, or a combination thereof.
The same effect can be obtained by adopting an orthogonal frequency division multiplexing (OFDM) system for orthogonalizing the plurality of carrier signals, or by performing double sideband modulation or single sideband modulation using the modulation signal or spreading code. .

FIG. 2 is a conceptual diagram showing another embodiment of the present invention, wherein 1 is a transmitting means, 2 is a receiving means, 21a, 21b, 21c and 21d are directional antennas, and 31 is the directivity of the antenna of the transmitting means 1. Patterns 31a, 31b, 31c and 31d are direction lines from the transmitting means 1 to the antennas 21a, 21b and 21c and 21d of the receiving means 2, and 32a, 32b and 32c and 32d are the directions of the antennas 21a, 21b and 21c and 21d. 22a is an external antenna switching synthesizer, 22e is a connection cable between the receiving means 2 and the external antenna switching synthesizer 22a, 33a is an extension line of the directivity 31, 33b and 33c are directivities 32a, 32b and 32c. , 32d, 34a, 34b, 34d, and 34e are dimension lines.
In FIG. 2, a high-frequency signal spread by a spread spectrum code is radiated from the transmitting means 1 in the direction of the antenna directivity 31, and the receiving means 2 has an external antenna 21c in addition to the built-in antennas 21a and 21b. And 21d are connected by a connection cable 22e with an interval 34a apart, and the antennas 21c and 21d are switched or synthesized by an external antenna switching synthesizer 22a.
In the receiving means 2, the high-frequency signal is detected from the difference in length between the direction lines 31 a and 31 b and 31 c and 31 d of the high-frequency signal received while periodically switching or changing the combination of the antennas 21 a and 21 b and 21 c and 21 d. When changes in amplitude, frequency, phase, or a combination of these are measured and the direction in which the transmitting means 1 is viewed from each of the antennas 21a, 21b and 21c, 21d is detected, the intervals between the antennas 21a, 21b and 21c, 21d are detected. Since 34a is known, the distance 34b between the transmission means 1 and the reception means 2 can be detected.
Here, when an 8-bit A / D converter is used for the receiving means, the direction measurement accuracy is ± 1 ° or less, but when a 10-bit or more device is used, the accuracy is improved to ± 0.1 °. Therefore, the distance 34b between the transmitting unit 1 and the receiving unit 2 can be detected with high accuracy.
If the position of the transmitting means 1 is known, the position of the receiving means can be detected by trigonometry.
Further, instead of installing and switching a plurality of antennas at intervals in the receiving means 2, similar effects can be obtained by installing and switching a plurality of antennas at intervals in the transmitting means 1.
In addition, the directional antenna of the transmitting means 1 is installed in the middle of the sidewalk, pedestrian crossing, roadway, roadway lane, barrier-free road, or movable width of the moving body. Controls the moving range when the moving body moves by detecting the deviation between the direction of the width of the moving body and the direction in which the center of the width of the moving body is facing and the direction in which the transmitting means is installed. Or can be guided.
Also, two antennas of the receiving means 2 are provided on both sides in the traveling direction or the backward direction at intervals of the width of the moving body, or at arbitrary intervals in the pedestrian's shoulders or both chests, in the left / right direction or in the vertical direction By providing the same, the same effect can be obtained.

FIG. 3 is a conceptual diagram showing another embodiment of the present invention, where 1 is a transmitting means, for example, an artificial satellite, 2 is a receiving means, 21a, 21b, 21c and 21d are directional antennas, and 22a is an external antenna. Switching combiner, 22b is a connection cable, 31 is a directivity pattern of the antenna of the transmitting means 1, 31a and 31b are virtual direction lines from the transmitting means 1 to the antennas 21a, 21b and 21c, 21d of the receiving means 2, 31c, 31d and 31e are reflected from the transmitting means 1 by the reflector or the relay means 41b and directed to the antennas 21a, 21b and 21c and 21d of the receiving means 2, and 32a, 32b, 32c and 32d are the antennas 21a and 21b. 21c and 21d directivity patterns, 33a is the ground direction line of the transmission means 1, 33b is the air direction line of the reception means 2, and 33c is the height of the transmission means 1. Outgoing line, 33d is a lead line at the height of the reflector or relay means 41b, 33e is a ground direction line of the reflector or relay means 41b, 34a, 34b, 34c, 34d are dimension lines, 41a is a shield, 41b is reflective 42a is an angle at which the reflecting object or relay means 41b looks up the transmitting means 1, and 42b is an angle at which the reflecting means or the reflecting point of the relay means 41b is looked up from the receiving means 2.
Assuming that the transmitting means 1 is, for example, a GPS artificial satellite, a two-dimensional plane is considered to simplify the explanation, and the high-frequency signal transmitted from the transmitting means 1 is shielded near the receiving means 2. The antennas 21a, 21b and 21c of the receiving means 2 via the direction lines 31d and 31e to the point shielded by the object 41a and reflected or relayed by the reflector or the relay means 41b via the direction line 31c; It is assumed that it is received by 21d. Here, when the transmission means 1 is located far enough, the angle at which the reception means 2 looks up the transmission means 1 is assumed to be substantially the same as the angle 41a at which the reflector or the relay means 41b looks up the transmission means 1.
Assuming that the transmitting means 1 is moving at a constant speed and the latitude, longitude and altitude for each hour are accurately known, the receiving means 2 has an angle to look up the transmitting means 1 from the record of its own position information. Is assumed to be β °, and the current approximate value is also known.
When the receiving means 2 uses the antennas 21a, 21b and 21c, 21d to measure the direction and distance in which the high-frequency signal arrives, if the angle 42b to be looked up is α ° and the distance is Lm, the sending means 1 The difference ΔX between the distance when the high-frequency signal transmitted from directly arrives and the distance reflected when reflected or relayed by the reflector or the relay means 41b is ΔX = LCos (α + β−90 °) × Cotβ Desired.
Here, in order to simplify the explanation, the case of a two-dimensional case has been described. However, four directional antennas are provided, and a total of eight directional antennas are provided to measure the three-dimensional direction and distance, thereby reflecting in all directions. The distance can be corrected for the reflected wave or diffracted wave from the object or the relay means 41b.
Further, when the horizontality of the plurality of directional antennas 21a, 21b, 21c, and 21d fluctuates, correction is performed using a gravity sensor, and the positional relationship between the plurality of directional antennas 21a, 21b, 21c, and 21d is determined by a geomagnetic sensor. Can be used to correct.
Even when the transmission means 1 is installed on the ground such as along a road or a pedestrian crossing instead of an artificial satellite, if the approximate position of the transmission means 1 is stored by a moving average, the reflector or the relay means 41b. By measuring the direction and distance, it is possible to calculate the exact distance from the transmission means 1.
Further, three or more antennas of the receiving means 2 are made into a set, for example, separated by about one-quarter wavelength of the wavelength of the high-frequency signal in the direction of front / rear, left middle / right, upper middle / lower, or a combination thereof. When arranged, the direction of ± 90 ° from the center line can be detected by measuring the phase difference between two adjacent antennas, and ± from the center line by measuring the phase difference between the two adjacent antennas. A 45 ° direction can be detected.
In addition, if the distance between the antennas in one set of the receiving means 2 is increased, the accuracy in measuring the direction is improved, but the measurable range is narrowed. First, the phase difference between adjacent antennas is measured to roughly determine the direction. A position or direction with a large dynamic range can be measured by measuring the phase difference between the antennas having a large interval and increasing the accuracy.
Moreover, although the case where the said receiving means 2 switches and measures several sets of antennas was demonstrated, the same effect is acquired even if it uses several receiving means.
Further, if the bandwidth of the relay means 41b is increased so that the delay time is negligibly small, it can be handled as the same reflector. When all the high frequency signals from a plurality of artificial satellites are received via the same relay means, the delay time of the relay means can be ignored.
In addition, the transmitting means is in a high altitude such as an artificial satellite, and the obstacle, reflector, or relay means is relatively short distance (experimental results show that those within 50 m have a large effect on errors in most cases. The degree to which the error such as the current position of the transmitting means or the angle of elevation affects the distance to be corrected is so small that it can be ignored.

FIG. 4 is a block diagram showing an embodiment of the receiving means of the present invention, wherein 2 is a receiving means, 21a and 21b are directional antennas, 22 is an antenna switching combiner, 23 is a receiver, 24 is a signal detection control unit, Reference numeral 25 denotes an operation display unit, 61 denotes an analog-digital converter, 62 denotes a signal detector, 63 denotes a reference oscillator, and 201, 202, and 203 denote connection terminals.
The antenna switching unit 22 is for switching between the antennas 21a and 21b while receiving the measurement spreading code transmitted from the transmitting means, and is driven by the signal detector 62 via the connection terminal 202, and the receiver 23 receives the signal. After the converted high frequency signal is converted to an intermediate frequency signal or a baseband signal, a reception output signal is output to the signal detection control unit 24 via the connection terminal 201.
The received output signal is converted into a digital signal by the analog-digital converter 61 in synchronization with the reference oscillator 63 and input to the signal detector 62. In the signal detector 62, the correlation with the fixed correlator for one period is taken, and the amplitude spectrum and the phase spectrum are detected by the product-sum operation with the lookup table of Sin, Cos, the fast Fourier transform, or other methods. From the amplitude spectrum and the phase spectrum, the signal detector 62 can detect the timing, amplitude, frequency, phase, or combination thereof in real time.
The amplitude of a signal having a large correlation with the fixed correlator is detected in the received output signal from the amplitude spectrum, and the phase of the carrier wave is detected from the phase spectrum. Thus, when the phase spectrum is detected when the amplitude spectrum exceeds the threshold while the interval between the directional antennas 21a and 21b is set to be one wavelength or less of the carrier wave of the high-frequency signal transmitted from the transmitting means, and the amplitude spectrum exceeds the threshold, the antennas 21a and 21b The direction in which the transmitting means is located can be detected from the phase difference between the two.
Here, the analog / digital converter is about 4 bits, and the difference between the advance signal and the delay signal of the spread code for each antenna is 1/100 or more by obtaining the moving average value of several tens of measurements. Therefore, if the length of one bit of each spreading code is 0.25 μs, the phase difference can be detected with an accuracy of 0.25 ns (7.5 cm) or less, and the frequency of the carrier wave is 2 .4 GHz, the wavelength length λ = 12.5 cm, so that the phase difference of the carrier wave can be detected with an accuracy of about 0.01 radians (0.2 mm), and an analog / digital converter 61 of 8 bits or more can be detected. By using it, the accuracy can be further improved.
Further, the direction of the directional antenna of the receiving means 2 is greatly swung left and right or up and down to detect the amplitude spectrum, thereby detecting the direction in which the magnitude of the input power received from the transmitting means is maximized. The function of measuring the phase difference can be supplemented.
Further, the AGC function is mounted on the receiver 23, and the gain of the receiver 23 can be suppressed so that the amplitude spectrum is not saturated.
When the receiver of the receiving means 2 is the Lower IF method or the direct conversion method, the signal detector 62 converts the output signal of the receiver into an intermediate frequency having the same frequency as the transmission rate of the spread code. Calculation can be facilitated.
In addition, when a digital signal processor is used to process the output signal of a receiver as in the past, power consumption increases, but real-time analysis is possible by using a high-frequency logic circuit that operates at high frequencies. The battery life can be extended.
In addition, a high-frequency logic circuit that operates at a high speed necessary for detecting a frequency spectrum is provided, and a product-sum operation is performed using the high-frequency logic circuit, a fast Fourier transform is performed, or an amplitude is calculated from the digital signal. The spectrum or phase spectrum or both are detected, or an average is calculated for an arbitrary period, or a window function is provided for calculation, or the detection results are displayed in time series for each arbitrary sampling number or arbitrary sampling period. Alternatively, time stamps can be output or combined.
A digital signal obtained by converting the output signal of the receiver in synchronization with the reference oscillator is stored in a multi-stage shift register, and at least four stages are selected from the shift register at an integer interval to form a set. Selects an integer to generate multiple sets of digital signals, or synchronizes the output signal of the receiver with a reference oscillator to convert it into digital signals at multiple types of sampling cycles, accumulates them in the shift register at each sampling cycle, and stores multiple A set of digital signals can be generated and a product-sum operation or a fast Fourier transform can be performed on the plurality of sets of digital signals to ensure the necessary resolution.
The high-frequency logic circuit operating at high speed is composed of at least a four-stage shift register, an exclusive OR circuit, and an adder, and can perform a product-sum operation between the digital signal and the Sin and Cos lookup tables. .
Also, the Sin lookup table used to detect the timing, amplitude, frequency, phase, or combination thereof in real time is 0, 1, 0, -1, or 1, 1, -1, -1, or these It is an integer multiple of 1 or a repetition of an integer, or the Cos lookup table is 1, 0, −1, 0 or 1, −1, −1, 1, or an integer multiple of these or a repetition of an integer. Or, multiplication of −1 when performing a product-sum operation can obtain the complement of the digital signal, or the combination of these can simplify the high-frequency logic circuit.

FIG. 5 is a diagram showing a basic configuration of the signal detector of the present invention, in which 51 is a spectrum spreading code transmitted by the transmitting means in a burst form, 52 is a shift register, and 53 is one cycle of the spread spectrum code generated by the receiving means. Fixed register of minutes, 54 is a ΣSin product-sum operation unit, 55 is a ΣCos product-sum operation unit, 56 is a delay time between transmitting means and receiving means, 57 is an amplitude spectrum detector, 58 is a phase spectrum detector, 59, 60 Is an output terminal.
It is assumed that one cycle or one code length of the spread spectrum code 51 transmitted by the transmitting means is composed of, for example, M series 8 chips.
The spread code 51 is transmitted, received by the receiving means, converted into a digital signal, and then sequentially input to the shift register 52 and branched into two outputs. In the fixed correlator 53 for one cycle, the digital signal input to the shift register 52 is correlated with each clock cycle, and the result is multiplied by the Sin lookup table by the ΣSin product-sum calculator 54 and added. Furthermore, the ΣCos product-sum calculator 55 multiplies the result by the Cos lookup table and adds the result.
The output of the ΣSin product-sum operation unit 54 and the output of the ΣCos product-sum operation unit 55 are, for example, squared and added by the amplitude spectrum detector 57 to obtain a square root, or add each absolute value, or add each absolute value. By adding the peak values, an amplitude spectrum is detected and output from the connection terminal 59, and a phase spectrum is calculated and output from the connection terminal 60 by obtaining a ratio between them by the phase spectrum detector 58.
The delay time 56 between the transmitting means and the receiving means is mainly caused by the delay time of the receiving means until one period of the spread spectrum code 51 transmitted by the transmitting means is input to the shift register 52 of the receiving means. A plurality of spread spectrum codes that are received by being reflected by some reflector or diffracted by an obstacle must always be one cycle of the spread spectrum code 51 of the transmitting means in order for each obstacle or reflector. Since the correlation output is maximized when the input is completed for one period, the delay time due to the obstacle or the reflection object can be detected in units of the chip length of the spread code.
Thus, a multipath is generated by being reflected or diffracted from any obstacle or reflector, and in accordance with the vector from the ΣSin product-sum calculator 54 and the ΣCos product-sum calculator 55 according to the spread spectrum code 51 received sequentially. Since the outputs are sequentially output, the time when the reflected wave or diffracted wave arrives can be measured by counting the number of clocks until the output exceeds the threshold value of the amplitude spectrum detector 57 and then exceeds the threshold value, and the amplitude The intensity of reflection or diffraction can be detected from the output of the spectrum detector 57, and the direction, height, or depth of the obstacle or reflector can be detected from the output of the phase spectrum detector 58 when the antenna is switched.
Here, the chip length of the spread spectrum code 51 and the wavelength of the carrier wave, subcarrier wave, or intermediate frequency signal of the high frequency signal are compared, and the cycle of whichever frequency is higher is twice or more (4 times the cycle is desirable). ) To convert to a digital signal.

FIG. 6 is a block diagram showing an embodiment of the transmitting means of the present invention, wherein 1 is a transmitting means, 11 is a directional antenna, 101 is an antenna switch, 102 is a transmitter, 103 is a receiver, 104 is a control unit, 105 Is a battery, 106 is a solar cell, 107 is a light emitter, and 108 is a directivity pattern.
The directional antenna 11 is enclosed in the transmitting means 1 and has a required directional pattern 108 such as a single radiation pattern or an 8-character radiation pattern. The output terminal of the antenna 11 is connected via an antenna switch 101. Are connected to the transmitter 102 and the receiver 103.
The transmitter / receiver 103 is controlled by the control unit 104. For example, the receiver 103 is in an intermittent reception state at all times, and when receiving a transmission request from the receiving means, the transmitter 102 is activated for a certain period of time, and the antenna switch 101 is switched and a high frequency signal is transmitted from the antenna 11.
On the other hand, as an optional function, the electric power generated by the solar cell 106 is stored in the battery 105 and supplied to each unit, and the light emitter 107 indicates the presence of the transmission means 1 at night or the modulator 122 is activated. In order to show that, all the parts constituting the transmission means 1 are housed in a waterproof case and have pressure resistance, impact resistance, vibration resistance performance, road surface, sidewalk surface or floor In addition to being embedded in the surface, it is used by attaching to dedicated pillars, street light poles, power line pillars, communication line pillars, walls, ceilings or other structures.
Further, instead of the directional antenna 11 of the transmitting means 1, a plurality of directional antennas are installed with an interval of one wavelength or less of the carrier wave, and are switched alternately by an antenna switching synthesizer, and an identification number for each directional antenna. Or change the spread code. The receiving means can identify an antenna that receives a single antenna and transmits the currently received high-frequency signal, and can detect the direction in which the transmitting means is located.

FIG. 7 is a perspective view showing an example of the configuration of the receiving means of the present invention. 2 is a receiving means, 21a, 21b, 21c and 21d are directional antennas, 301 is a radome, and 302a and 302b are intervals of the directional antennas. .
The receiving means 2 is housed in a cylindrical shape that is easy to hold with one hand, a housing with a handle, or a structure convenient for carrying, and directional antennas 21a to 21d are housed in a radome 301 provided on the front surface. The directional antennas 21 a to 21 d are directed in the same direction and are switched or combined by an antenna switching combiner and connected to a receiver built in the receiving means 2.
The length 302a between the directional antennas 21a and 21d and the directional antennas 21b and 21c and the length 302b between the directional antennas 21a and 21b and the directional antennas 21c and 21d are, for example, high frequencies received by the receiving means. The length is set to about a quarter of the carrier wave of the signal.
When the directivity direction of the directional antennas 21a to 21d is directed to the direction of the transmitting means existing in the vicinity, when the center line of the directional antennas 21a to 21d coincides with the direction of the transmitting means, each directivity is set. The phase of the carrier wave of the high-frequency signal input to the directional antenna is completely the same, and the phase difference of the carrier wave of the high-frequency signal received by switching these directional antennas is very small. When shifted from the direction, the phase difference of the carrier wave when the directional antenna is switched increases.
For example, when the center line is shifted left and right from the direction of the transmitting means, the phase difference of the carrier wave between the directional antennas 21a and 21b and the directional antennas 21c and 21d is small, but the directivity is small. The phase difference of the carrier wave between the antennas 21a and 21d and between the directional antennas 21b and 21c increases. Since the interval between the four directional antennas is set to a quarter wavelength of the high-frequency signal, the phase difference of the carrier wave when the direction of the center line is shifted ± 90 ° to the left or right from the direction of the transmitting means. Is shifted by ± 90 °.
On the contrary, if the center line deviates up and down from the direction of the transmitting means, the phase difference of the carrier wave between the directional antennas 21a and 21d and the directional antennas 21b and 21c is small, but the directivity The phase difference of the carrier wave between the directional antennas 21a and 21b and between the directional antennas 21c and 21d increases. Since the interval between the four directional antennas is set to a quarter wavelength of the high-frequency signal, the phase difference of the carrier wave when the direction of the center line is shifted ± 90 ° vertically from the direction of the transmitting means. Is shifted by ± 90 °.
In order to detect the azimuth with high accuracy, it has been confirmed through experiments that the measurement accuracy can be increased by increasing the isolation between the antennas 32a and 32b of the receiving means 2.
On the other hand, between the directional antennas 21a and 21c on the diagonal line and between the directional antennas 21b and 21d, the phase difference of the carrier wave is greatly increased regardless of which direction is left, right or up.
When measuring the phase difference of the carrier wave of the high-frequency signal, if the phase difference exceeds ± 90 °, it becomes difficult to specify the direction of the center line, so it is necessary not to exceed this range. When arranged, this range does not exceed this range unless the carrier wave comes from behind. When the carrier wave comes from behind, it can be determined using a geomagnetic sensor or the like as an auxiliary.
When the direction of the receiving means of the present invention is searched forward in the manner that a direction person illuminates the flashlight, the direction in which the transmitting means is present can be measured with high accuracy, so that the directivity of the antenna of the transmitting means is directed along a safe sidewalk. Then, since a pedestrian can walk accurately in the direction of the said transmission means along the direction of the directivity of the said transmission means, a safe walk can be ensured.
In the above description, four directional antennas are used. However, receiving means according to the purpose can be realized by any combination of two or more. In particular, when the interval between the directional antennas is larger than a quarter of the wavelength of the carrier wave and is, for example, a half wavelength, when the direction of the center line and the direction of the transmitting unit are shifted by ± 30 °, Since the phase difference of the carrier wave is ± 90 °, it is possible to measure with higher accuracy.
Here, if the 2.4 GHz band is used as the frequency of the carrier wave of the high-frequency signal, the diameter of the radome will be about 6 cm even when four directional antennas are attached, and it will be the same size as a large flashlight. A device for supporting pedestrians that can be carried and used by a person with great convenience can be realized.
In addition, since the receiving means 2 is equipped with a means for transmitting a transmission request signal to the transmitting means, the transmitting means can be kept in a standby state at all times, so that radio waves can be used effectively and power consumption of the transmitting means can be reduced. It can be driven by a solar cell or the like.
In addition, a gravitational sensor is incorporated in the receiving means 2, and by distinguishing between a directional antenna located in the left and right direction and an up and down direction, there is an advantage that extra care can be omitted when carrying the receiving means. Out.
In addition, it is possible to facilitate handling or operation by phase-combining a plurality of antennas of the receiving means 2 and controlling the directivity of the antennas to search the transmitting means for directions.
Further, instead of providing a plurality of antennas in the receiving means 2, a plurality of antennas are provided on the transmitting means side, and a high-frequency signal is transmitted by switching with an antenna switching synthesizer, and the receiving means 2 uses a single or a plurality of antennas. It is also possible to detect the direction in which the transmitting means is installed by measuring the phase difference of the high-frequency signal between the plurality of antennas on the transmitting means side.
Further, when switching the plurality of antennas of the receiving means 2, instead of always switching the switching order from 21a to 21d in one direction, alternately switching from 21d to 21a in the reverse direction and subtracting the detected phase difference. Thus, a basic error caused by a change in the frequency of the reference oscillator or a change in the transmission time or transmission phase of the circuit can be eliminated.
In addition, when the antenna of the transmission means is installed along the sidewalk or in the safety zone of the pedestrian crossing, if the right side is dangerous and the left side is safe, it should be determined that the right-hand traffic is possible So visually impaired people can safely walk.
Further, a reference direction preset in a display device or audio device provided or connected to the receiving means 2 is set as a direction in which the moving subject possessing or installing the receiving means 2 is currently facing. The moving subject can easily change the direction by displaying, pointing, or announcing the direction to be traveled for the purpose.
Further, the receiving means 2 can be used in a hand-free manner by being mounted on the head in the form of a headlamp or mounted on the chest vest.
In addition, when two antennas of the receiving means 2 are arranged, in the case of 2.4 GHz, the width is about 3 cm and the length is about 6 cm, which is about the size of glasses. Is also possible.

FIG. 8 is a block diagram showing another embodiment of the antenna switching synthesizer of the present invention, in which 21a and 21b are antenna elements, 22 is an antenna switching synthesizer, 223a and 223b are delay circuits, 224a and 224b are circulators, 225 Is an antenna switch, 226 is a bifurcater, 227 is a correlator (N-1), 228a, 228b, and 228c are connection terminals. Here, the distance between the antennas 21a and 21b is λ / 4 of the wavelength of the carrier wave of the high-frequency signal.
This antenna switching synthesizer 22 corresponds to a relay means or a passive tag. A transmitting means is connected to the connection terminal 228a, and for example, a high-frequency signal spread by a spread spectrum code (N) in the 2.4 GHz band. Is applied. The high-frequency signal is branched into two by a two-branch unit 226, and most of the high-frequency signal is delayed by delay circuits 223a and 223b via circulators 224a and 224b, and is radiated to the space from antennas 21a and 21b. It wraps around the switch 225.
On the other hand, the high frequency signals received by the antennas 21a and 21b are delayed by the delay lines 223a and 223b, switched by the antenna switch 225 via the circulators 224a and 224b, and three-branched by the three-branch unit 226b, respectively. 227b and 227c are correlated with the spread spectrum codes input from the connection terminals 228e, 228f and 228g, and output from the connection terminals 228b, 228c and 228d.
The power that a part of the high-frequency signal (PdBm) applied to the connection terminal 228a wraps around to the antenna switch 225 is about P-3dB-20dB = P-23dB. Further, the correlator 227a is provided so as to correlate with the spectrum spread code (N-1) applied to the connection terminal 228a, and the high-frequency signal that wraps around is spread by the spread spectrum code (N). The correlator 227a correlates the spread spectrum codes (N) and (N-1), and the high-frequency signal that wraps around is improved by 10 log (W1 / W2) dB.
Here, P is the power of the high frequency signal applied to the connection terminal 228a and is 10 mW, W1 is the spread spectrum band of the transmitting means and 50 MHz, and W2 is the bandwidth of the intermediate frequency signal of the receiving means is 10 Hz. The power of the high-frequency signal that wraps around the connection terminal 228b is 10 dBm-23 dB-10 log (50 MHz / 10 Hz) =-80 dBm.
The delay lines 223a and 223b receive the spread spectrum code (N) when the high-frequency signal is radiated from the antennas 21a and 21b to the space, relayed by the relay means, received again by the antennas 21a and 21b, and reaches the circulators 224a and 224b. This is for delaying to (N-1), and a minimum delay amount corresponding to 1/2 chip of the spread spectrum code is necessary.
Assume that the relay means has an amplification factor of 20 dB when looping back, the gain of the antennas 21a and 21b of the transmission means and the reception means is 14 dBi at the time of transmission, 9 dBi at the time of reception, and the antenna gain of the relay means is 11 dBi at the time of reception and transmission. If the minimum input level of the receiving means is −60 dBm, the one-way allowable loss is about 69 dB, and the distance between the transmitting means and the relay means is allowed to be about 36 m.
Note that the delay amount by the delay circuits 223a and 223b is required to be 10 nsec or more, which is half of 20 nsec when the transmission rate of the spread spectrum code is 50 Mbps.
Further, the same effect can be obtained by applying a non-modulated high-frequency signal to the connection terminal 228a and performing spectrum spreading by the relay means and turning it back. However, in this case, the delay circuits 223a and 223b are unnecessary.
In addition, the connection terminal 228a is a plurality of connection terminals, a high frequency signal spread by a different spread spectrum code is applied to each of the connection terminals 228a, the bifurcater 226 is deleted, and the circulators 224a and 224b are connected. The same effect can be obtained by switching the two spread spectrum codes to two types of spread spectrum codes on the transmitting means side in conjunction with the antenna switch 225.

FIG. 9 is a block diagram showing an embodiment of the relay means of the present invention, wherein 1 is a relay means, 11a and 11b are directional antennas, 121 is a band pass filter, 122 is a modulator, 123 is a signal generator, and 124 is An amplifier, 105 is a battery, 106 is a solar cell, 107 is a light emitter, and 108a and 108b are directivity patterns.
The relay unit 1 is one form of a transmission unit, modulates a received high frequency signal, amplifies it, and retransmits it. The relay means 1 includes a directional antenna 11b, a band pass filter 121, a modulator 122, a signal generator 123, an amplifier 124, and a directional antenna 11a.
The directional antennas 11a and 11b are, for example, circularly polarized directional antennas that are reversely swiveled with each other, and are spaced apart so as to obtain a required coupling loss. The radiation patterns 108a and 108b are usually parallel to each other. Is directed in the direction.
The output terminal of the directional antenna 11 b is connected to a modulator 122 with a band limited by a band pass filter 121, and the subcarrier spread by the spread spectrum code generated by the signal generator 123 in the modulator 122. The output of the modulator 122 is amplified by the amplifier 124 and retransmitted from the directional antenna 11a.
The modulator 122 is a double-sideband modulator using, for example, a double balance mixer. When a spectrum-spread subcarrier is applied, a spectrum-spread high-frequency signal separated by the frequency of the subcarrier is generated on both sides of the center frequency. . The relationship between the two high-frequency signals appearing on both sides is orthogonal to each other, and the distance between the relay unit 1 and the receiving unit can be detected by this relationship. Note that the modulation scheme of the modulator 122 is not limited to double-sideband modulation, and any modulation scheme may be used as long as it can generate a plurality of orthogonal carriers. The received high-frequency signal may include a plurality of carriers that are already orthogonal. Any modulation method may be used.
Incorporating a receiver and a controller in the relay means 1 and starting up or intermittently operating with a signal received from an external transmission means or a mobile phone, etc., thereby reducing the power consumption compared to the case of always operating. be able to.
When the high-frequency signal modulated from the directional antenna 11a is retransmitted, a part of the high-frequency signal is coupled in space and received by the directional antenna 11b. When the modulator 122 is double-sideband modulated, it can be driven out of the passband width of the bandpass filter 121 and is largely blocked by the bandpass filter 121, so that the gain of the amplifier 124 is attenuated by the bandpass filter 121. Mutual interference or parasitic oscillation can be prevented as long as it is less than the amount.
The gain of each of the directional antennas 11a and 11b is G1 dB, the coupling loss between the two is L0 dB, the modulated bandwidth of the high-frequency signal transmitted from the directional antenna 11a is W1 (MHz), and the bandwidth of the bandpass filter 121 If the width is W2 (MHz), the so-called process gain PG is PG = 10 × log (W1 / W2) dB. If the gain of the amplifier 124 is G2 dB, the high-frequency signal transmitted from the directional antenna 11a is a directional antenna. The ratio of wrapping around 11b, that is, the coupling loss L is L = L0 + 10 × log (W2 / W1) + S (dB). Here, S is a coupling loss between the right-turning and left-turning directional antennas 11a and 11b, and about 10 dB can be secured.
If the interval between the directional antennas 11a and 11b is about a half wavelength, L0 = 22 dB, the process gain is PG = W1 / W2 = 100 = 20 dB, and the coupling loss between the right-turn and left-turn antennas is about 10 dB. , L = 22 + 20 + 10 = 52 dB, so that the gain of the amplifier 124 can be secured at about 47 dB.
The transmission loss T until the high frequency power transmitted from the portable terminal is returned by the relay means 1 and received again by the portable terminal is T = 2 × 20 × log (D / λ) −2G1−G2. Here, D = distance between the portable terminal and the relay means 1 and about 68 dB when the distance is 24 m in the 2.4 GHz band, so T = 2 × 68−2 × 9 dB−47 dB = 71 dB. Since this value is almost the same as the one-way transmission loss 68 dB, it is equivalent to the case where the relay means 1 itself transmits a high-frequency signal.
On the other hand, the electric power generated by the solar cell 106 is stored in the battery 105 and supplied to each part, and the light emitter 107 indicates the presence of the relay means 1 at night or indicates that the modulator 122 is activated. Except for intermittent lighting, the same effect as the transmitting means can be obtained.
Further, the modulator 122 can output a high-frequency signal having a plurality of orthogonally spread carriers by performing amplitude modulation or double sideband modulation using the spread spectrum subcarrier signal, and the relay means. The distance between the receiving means can be detected. The circuit can be simplified by using a double balance mixer that operates directly in the frequency band of the high-frequency signal as the double-sideband wave modulator.
Further, a part of the output of the amplifier 124 is directly coupled to the input of the band-pass filter 121 via a variable phase shifter and a variable attenuator, and the output of the directional antenna 11a directly wraps around the directional antenna 11b to cause interference. It is also possible to cancel the wraparound by monitoring the degree to be controlled and controlling the phase of the phase shifter.
Further, the identification number, identification code or data of the relay means 1 can be included in the modulation signal or subcarrier or spread spectrum code generated by the signal generator 123, or the delay time of the relay means 1 can be set as data. Can be included as
Further, by setting the relay means 1 as a wide-band straight amplifier and setting the amplification degree of the amplifier smaller than the isolation between the directional antennas 11a and 11b, the delay time can be reduced as much as possible.

In the above description, the numerically controlled oscillator is used, but the same effect can be obtained by an equivalent method such as using a digital PLL circuit.
Although the digital method has been described as the autocorrelator, the same effect can be obtained even if the analog method is used.
Further, an ultrasonic signal is transmitted from the transmitting means using an ultrasonic transducer or an ultrasonic transmitter, and an ultrasonic signal is received using an ultrasonic transducer or an ultrasonic receiver in the receiving means, Alternatively, a similar effect can be obtained by transmitting an optical signal using a light emitting diode or a laser diode in the transmitting means and receiving an optical signal using a photodiode in the receiving means. In the present application, the ultrasonic transducer or ultrasonic transducer and the light emitting diode, laser diode or photodiode are collectively referred to as a transducer.
Further, the same effect can be obtained by measuring the phase difference of the carrier wave of the high-frequency signal that is not modulated or modulated by the analog signal or the digital signal without performing the spread spectrum.
The same effect can be obtained by directly converting the spread spectrum code into an ultrasonic signal, a high-frequency signal, or an optical signal in the transmitting means or relay means.
Further, instead of switching a plurality of antennas, the same effect can be obtained by separately providing receiving means corresponding to the plurality of antennas and measuring the phase difference between the receiving means.
In addition, if there are obstacles such as pedestrians around the mobile terminal, the ultrasonic signal, high-frequency signal or optical signal transmitted from the active tag may be blocked or reflected to cause an error due to multipath. Therefore, it is desirable to use a directional antenna with a sharp directivity for the active tag and to set the directivity so that it is installed at a relatively high position and blows down from above.
In addition, multiple antennas or transducers are connected in series or in parallel by cables, or constitute a leaky cable, installed along the direction of travel of pedestrians or moving objects, or installed in the periphery of specific areas. Guidance or specific area guidance can be effectively performed.
Further, the direction and distance can be detected by modulating the high-frequency signal generated by the transmitting means as a subcarrier and radiating it to the space, and demodulating the high-frequency signal from the optical signal received by the receiving means.
In addition, the transmitting means can be integrated with a solar cell and a capacitor for storage and housed in a thin waterproof case so that it can be embedded in the road surface or pasted on the surface of a transported object for a long time. .
The same effect can be obtained even if each means is mounted on, mounted on, or carried by a flying object including a satellite or a moving object including an automobile, a pedestrian, or a robot.
A similar effect can also be obtained by outputting the plurality of antennas divided into at least two groups by a switching synthesizer and obtaining the correlation between the two groups.
In addition, when the receiving means, the transmitting means, the relay means, or any combination thereof has a plurality of antennas, when a plurality of antennas of one means are switched, a plurality of antennas of other means can be fixed. The direction or distance can be easily detected or the detection accuracy can be maintained.
In addition, when the transmitting means is incorporated into a ball for ball games such as golf or baseball together with an element that generates electric power by impact, the high-frequency signal is transmitted by impact at the time of hitting or kicking, and the trajectory of the ball is accurately tracked. Can do.
Further, the antenna of the transmitting means has a spherical shape or an elliptical spherical shape, and it is possible to suppress leakage of unnecessary high-frequency signals to the outside by incorporating circuit components therein.
Further, in the transmitting means or the relay means, electric power supplied by electromagnetic induction from a commercial power supply, high frequency power of 2.4 GHz band radiated from a microwave oven or an oscillator, etc., or energy of vibration or impact applied from the outside is stored. Alternatively, continuous operation is possible by charging the battery.

It is a conceptual diagram which shows one Example of this invention. It is a conceptual diagram which shows the other Example of this invention. It is a conceptual diagram which shows the other Example of this invention. It is a block diagram which shows the Example of the receiving means of this invention. It is a block diagram which shows the Example of the signal detector of this invention. It is a block diagram which shows the Example of the transmission means of this invention. It is a perspective view which shows the structural example of the receiving means of this invention. It is a block diagram which shows the Example of the antenna switching synthesizer of this invention. It is a block diagram which shows the Example of the relay means of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transmission means 2 Reception means 11, 11a, 11b Directional antenna 21a, 21b, 21c, 21d Directional antenna 22, 22a Antenna switching combiner 23 Receiver 24 Signal detection control part 25 Operation display part 31, Antenna of transmission means 1 Directivity patterns 31a, 31b Direction lines 31c, 31d, 31e from the transmitting means 1 to the antennas 21a and 21b and 21c and 21d of the receiving means 2 from the transmitting means 1 to the reflector 41b and from the reflector 41b to the receiving means 2 Directional lines 32a, 32b, 31c, 31d toward antennas 21a and 21b and 21c and 21d Antennas 21a and 21b and directivity 33a of 21c and 21d Extension lines 33b, 33c, 33d and 33e of directivity 31 Lead lines 34a and 34b , 34c, 34d Dimension line 41a Shield 41b Reflector 42a Angle 42b at which the transmitting means 1 is looked up from the projectile 51 Angle at which the reflecting means 41b is looked up from the receiving means 2 Spelltle spread code 52 generated by the transmitting means Shift register 53 Fixed correlator 54 for one period ΣSin product-sum calculator 55 ΣCos product-sum Operation unit 56 Delay time 57 between transmission means and reception means 57 Amplitude spectrum detector 58 Phase spectrum detector 59, 60 Connection terminal 61 Analog-digital converter 62 Signal detector 63 Reference oscillator 101 Antenna switch 102 Transmitter 103 Receiver 104 Control unit 105 Battery 106 Solar cell 107 Light-emitting diode 108, 108a, 108b Directional pattern 121 Band pass filter 122 Modulator 123 Signal generator 124 Amplifier 201, 202, 203 Connection terminal 223a, 223b Delay circuit 224a, 224b Circular 225 Antenna switch 226 Branch 227 Correlator (N-1)
228a, 228b, 228c Connection terminal 301 Antenna radome 302a, 302b Antenna spacing

Claims (19)

In a moving body detection system using an ultrasonic signal, a high-frequency signal, or an optical signal,
The transmitting means for transmitting an ultrasonic signal, a high frequency signal or an optical signal, and a receiving means for receiving an ultrasonic signal, a high frequency signal or an optical signal transmitted from the transmitting means,
At least one of the transmitting means and the receiving means is attached to or carried by a moving body,
The signal transmitted by the transmission means is composed of at least an identification signal for identifying the transmission means and a measurement signal for measurement,
The measurement signal is composed of a plurality of carrier signals, a plurality of subcarrier signals, a plurality of sideband signals, a plurality of modulation signals, a plurality of spreading codes, or a combination thereof, which are synchronized and / or orthogonal, and have different frequencies. ,
The transmission means transmits the measurement signals simultaneously or sequentially,
Said transmitting means or the receiving means or both of them, and a plurality of antennas or a plurality of transducer arranged at intervals of less than one wavelength of the carrier signal or subcarrier signal of the measurement signals, the plurality of antennas or a plurality A switching synthesizer for periodically switching and / or changing the combination of
A carrier signal or subcarrier signal or sideband signal or a receiver for extracting the modulated signal or the spread code from the measuring signal the receiving means is transmitted from said transmitting means, the reference oscillator output signal of the receiver Having a signal detector for synchronously converting to a digital signal and processing the digital signal;
In the signal detector, the identification signal is processed to identify the transmitting means, and the measurement signal is processed to process at least a carrier signal or a subcarrier signal corresponding to the plurality of antennas or the plurality of transducers. detects the frequency and / or phase, the detection result together with the transmitting means detects a direction in which towards the direction or the reception means located from a plurality of carrier signals to be synchronized and / or perpendicular of the measurement signal Alternatively, at least the frequency and / or phase corresponding to the subcarrier signal, the plurality of modulation signals, the plurality of spreading codes, or a combination thereof is detected, and the distance from the transmitting unit to the receiving unit is detected from the detection result. Active tag device characterized by. In the transmission means, the carrier signal or subcarrier signal is spread by a spread spectrum code to generate the measurement signal,
The spread spectrum code is composed of a short-cycle code sequence for establishing synchronization in at least a short time and a relatively long-cycle code sequence for measurement or a repetition of a short-cycle code sequence and / or the measurement. Part or all of the signal is replaced with an unmodulated carrier signal or subcarrier signal,
2. The receiver according to claim 1, wherein at least a carrier signal or a subcarrier signal is extracted from the measurement signal by despreading the generated spread spectrum code or performing Nth power or N multiplication. The active tag device according to item. The transmitting unit receives an ultrasonic signal, a high-frequency signal or an optical signal transmitted from a second transmitting unit other than the transmitting unit, and a direct or necessary conversion of the signal received by the receiving unit. Or having a relay means for performing necessary modulation or re-spreading or relaying with spread spectrum,
In the relay unit, Akuteibu tag device of claim 1 wherein, wherein generating a measurement signal for measurement and identification signals for identifying the calling unit. The transmitting means transmits the measurement signal by orthogonal frequency division multiplexing, transmits the signal by frequency hopping, or modulates the amplitude using an arbitrary modulation signal, or modulates the single sideband or modulates both sidebands. The active tag device according to claim 1, wherein the active tag device transmits the information by a combination thereof . In the transmitting unit, wherein the includes a synchronization signal to the identification signal or the measurement signal, the synchronization signal a plurality of antennas or a plurality of transducer periodically switching or changing the combination as a reference, in the receiving unit, the synchronization 2. The method according to claim 1, wherein at least frequencies and / or phases of carrier signals or subcarrier signals corresponding to the plurality of antennas or the plurality of transducers are detected in real time in a short time with reference to signals. The active tag device as described. In the case of detecting at least the frequency and / or phase of the carrier signal or subcarrier signal corresponding to said plurality of antennas or a plurality of the transducer by the signal detector, switching the first order or first direction It is or the opposite combination between the detected value is changed and the first order second order or the first direction and the value detected being changed is or combined switch in a second direction opposite Or a difference between the value detected by the first antenna or the transducer and the value detected by the first antenna or the transducer again by switching or changing the combination. The active tag device according to claim 1, wherein a detection error is corrected by the method. In order to detect at least the frequency and / or phase of the carrier signal or subcarrier signal in real time in a short time, the product-sum operation is performed by providing the necessary number of high-frequency logic circuits that operate at high speed according to the resolution. The active tag device according to claim 1, 4, or 6 , wherein the operation is performed by taking an average of periods or providing a window function. In units of at least one cycle of the carrier signal or subcarrier signal extracted by said receiver, at a sampling frequency synchronized with the reference oscillator into a digital signal stored in the shift register, the digital signal and at least one cycle perform product-sum operation of the Sin and Cos of the look-up table, the claim paragraph 1 or 7, wherein the detecting in real time a short time the frequency and / or phase of the carrier signal or subcarrier signal The active tag device according to item. Wherein the plurality of antenna or plurality of transducer is arranged in the direction of the longitudinal direction or lateral direction or vertical direction or symmetrical directions or combinations thereof mobile, or of the plurality of antenna or plurality of transducer The active tag device according to claim 1, wherein the interval is a structure that can be extended during use. The antenna or directional beam of the transducer of the transmitting means side is relatively narrow, the receiving unit side of the antenna or the wave transceiver directional beam is relatively large, or the directivity of the beam at the time of calling 2. The active tag device according to claim 1, wherein the directional beam is widened when the aperture is received so that the direction of the transmitting means can be easily supplemented and is not easily affected by multipath. A plurality of antennas or a plurality of transducer is plural sets connected to said receiving means and / or said transmitting means, said plurality of sets are arranged in one wavelength or more intervals of the carrier signal or subcarrier signal, detecting the direction Akuteibu tag device of claim 1 wherein, wherein the adding enhanced and / or the transmitting means functions to a function of detecting the distance between the receiving means. Along the interior and / or peripheral portions or areas of the area where the moving body is allowed to move can or it safely, a plurality of antennas or a plurality of transmission and reception waves that are connected to a plurality of said transmitting means is installed or the transmitting means A vessel is installed to assist or guide the mobile body to move along or out of the area ,
The transmission means is notification information regarding traffic signals and / or notification information regarding the area.
The active tag device according to claim 1, wherein information is transmitted . Said receiving means mounted geomagnetic sensor or an acceleration sensor or gravity sensor or GPS receiver, or a combination thereof Akuteibu of claim 1 wherein, characterized in that the sensing results complement or correction of the receiving means Tag device. The second transmitting means is a GPS satellite, and a high-frequency signal transmitted from the GPS satellite is relayed by the relay means and arrives at the receiving means. In the receiving means, a direction in which the relayed high-frequency signal arrives 4. The active tag device according to claim 3 , wherein the position of the receiving means detected using the GPS satellite is corrected by detecting a distance from the relay means. The receiving means is installed and fixed at a distance at a plurality of locations are connected between each other through a communication line, the direction and / or distance are mounted on mobile or portable by said transmitting means is located the result has been detected, and transmitted to the central unit via the communication line, Akuteibu of claim paragraph 1, wherein the transmitting means in the central device and displaying the direction and / or distance situated Tag device. Akuteibu tag device of claim 1 wherein the plurality of antennas is equal to or shared with diver DF antenna fixed radio stations or mobile radio station of the transmission means or said receiving means. The transmitting means or the receiving means has a structure that can be easily attached and detached, and is attached to or in the vicinity of an illuminating lamp or a lighting fixture, or is supplied with electric power, and the number of the lighting fixture or installation location or a corresponding point. 2. The active tag device according to claim 1, wherein an identification number indicating a characteristic of a place or an area is transmitted. In the transmission unit, it transmits a spread-spectrum code of ultra-wideband directly as ultrasonic signals or radio frequency signals, or claim first term or the second, characterized in that transmits by modulating the optical signal directly by the spectrum spreading code The active tag device according to Item 2. In the plurality of antennas or transducers, a beam is formed in the direction of a desired wave by controlling the phase of an ultrasonic signal, a high-frequency signal, or an optical signal to be transmitted or received, and adaptively combining them to disturb A null is formed in the direction of the wave, and the direction and / or distance in which the target transmission means is located is detected from the control result of the phase or the control result of the phase. Akuteibu tag device of claim 1 wherein the.

Images