Passive positioning device

Abstract

The invention proposes a passive positioning device, and the device comprises a passive positioning tag which receives a positioning signal of a first frequency transmitted by a detection device through a positioning antenna, and transmits a feedback signal of a second frequency to the detection device according to the positioning signal of the first frequency, the detection device determines the position of the positioning label according to the feedback signal of the second frequency; the radio frequency tag is in coupling connection with the card reader through a radio frequency antenna, and the radio frequency tag receives a carrier signal sent by the card reader, generates an induced current according to the carrier signal and sends coded information to the card reader; wherein the absolute value of the difference value between the frequency of the positioning antenna and the frequency of the radio frequency antenna is greater than or equal to a preset value. According to the invention, the position of the trapped person can be positioned during rescue, and the related information of the trapped person can be obtained at the first time after the trapped person is found, so that the rescue efficiency is greatly improved.

Description

Technical Field

[0001] This application relates to the field of position location and information reading, and particularly relates to a passive positioning device. Background Art

[0002] In a complex and harsh environment, it is difficult to accurately determine the specific position of a person or an object (personal equipment) through cluster communication in a short time. Carrying too much equipment will also increase the burden on rescue personnel and is not conducive to rescue operations. In addition, the failure of satellite positioning signals and the limitation of uplink also promote the research and development of new technologies, especially in scenarios such as cliffs or under snow. Therefore, as the last guarantee for rescue personnel, the intelligent combination of rescue clothing and rescue equipment has become a development trend. The positioning tag can be flexibly embedded in clothing, shoes or equipment. However, the current positioning tag only has the positioning function and does not have functions such as information identification. Due to the relatively long detection distance, it is also impossible to effectively transmit information technically. In this way, even if the position information of the trapped person is located through the positioning tag, the identity of the trapped person cannot be known in the first time, which seriously affects the overall rescue efficiency. Summary of the Invention

[0003] To solve one of the above technical problems, the present invention provides a passive positioning device.

[0004] The first aspect of the embodiment of the present invention provides a passive positioning device, which includes:

[0005] A passive positioning tag, which receives a positioning signal of a first frequency emitted by a detection device through a positioning antenna and emits a feedback signal of a second frequency to the detection device according to the positioning signal of the first frequency, so that the detection device determines the position of the positioning tag according to the feedback signal of the second frequency;

[0006] A radio frequency tag, which is coupled to a card reader through a radio frequency antenna. The radio frequency tag receives a carrier signal emitted by the card reader, generates an induced current according to the carrier signal, and sends encoded information to the card reader;

[0007] Wherein, the absolute value of the difference between the frequency of the positioning antenna and the frequency of the radio frequency antenna is greater than or equal to a preset value.

[0008] Preferably, the first frequency is determined by the power of the detection device and the detection distance, and the first frequency and the second frequency are in a multiple relationship.

[0009] Preferably, a filter is provided in the positioning antenna and / or the radio frequency antenna.

[0010] Preferably, a shielding layer is provided between the positioning antenna and the radio frequency antenna.

[0011] Preferably, a non-linear element for resonance is provided in the passive positioning tag.

[0012] Preferably, the RF tag includes an RF antenna, a rectifying circuit, a micro switch, an RF chip, a load modulation circuit, and a memory. A coupling element is provided in the RF antenna. The coupling element is used to sense the carrier signal emitted by the coupling element in the reader antenna and generate an induced current. The induced current passes through the rectifying circuit and activates the micro switch to supply power to the RF chip. The RF chip transmits the encoded information stored in the memory to the reader through the load modulation circuit according to the carrier signal through the RF antenna.

[0013] Preferably, the RF antenna and the reader antenna are connected by inductive coupling.

[0014] Preferably, the carrier signal uses ASK and PSK modulation methods to transmit the encoded information stored in the memory to the reader through the load modulation circuit through the RF antenna.

[0015] In a second aspect of the embodiments of the present invention, a passive positioning device is provided. The passive positioning device includes:

[0016] A passive positioning tag that receives a positioning signal of a first frequency emitted by a detection device through a fundamental frequency antenna and emits a feedback signal of a second frequency to the detection device according to the positioning signal of the first frequency, so that the detection device determines the position of the positioning tag according to the feedback signal of the second frequency;

[0017] An RF tag that is coupled to a reader through a fundamental frequency antenna. The RF tag receives a carrier signal emitted by the reader, generates an induced current according to the carrier signal, and transmits encoded information to the reader;

[0018] A toggle switch. When in the initial position, the fundamental frequency antenna is connected to the passive positioning tag. After the passive positioning tag emits a feedback signal to the detection device, the toggle switch switches positions, and the fundamental frequency antenna is connected to the RF tag.

[0019] Preferably, the fundamental frequency antenna and the reader antenna are connected by inductive coupling.

[0020] The beneficial effects of the present invention are as follows: The passive positioning device proposed by the present invention combines the positioning function of the passive positioning tag and the information reading function of the RF tag, and realizes the passive function of the RF tag through a coupling connection method. It does not require manual intervention, can be used in various harsh environments, is quick and convenient to operate, has a low manufacturing cost, and is easy to use. It can locate the position of trapped people during rescue and obtain relevant information of the trapped people immediately after finding the trapped people, greatly improving the rescue efficiency. Description of the Drawings

[0021] The accompanying drawings described herein are used to provide a further understanding of the present application and form a part of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation to the present application. In the drawings:

[0022] Figure 1 It is a schematic diagram of the principle of a passive positioning device according to Embodiment 1 of the present invention;

[0023] Figure 2 It is a schematic diagram of the principle of the coupling connection between a card reader and a radio frequency tag according to Embodiment 1 of the present invention;

[0024] Figure 3 It is a schematic diagram of pulse interval coding according to Embodiment 1 of the present invention;

[0025] Figure 4 It is a schematic diagram of the principle of a radio frequency tag according to Embodiment 1 of the present invention;

[0026] Figure 5 It is a schematic diagram of the principle of a passive positioning device according to Embodiment 2 of the present invention;

[0027] Figure 6 It is a schematic diagram of the connection between a fundamental frequency antenna and a passive positioning tag when the toggle switch is in the initial position according to Embodiment 2 of the present invention;

[0028] Figure 7 It is a schematic diagram of the connection between a fundamental frequency antenna and a radio frequency tag when the toggle switch is switched according to Embodiment 2 of the present invention. Detailed implementation manners

[0029] In order to make the technical solutions and advantages in the embodiments of the present application clearer and more understandable, the following further describes the exemplary embodiments of the present application in detail with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than an exhaustive list of all embodiments. It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0030] Embodiment 1

[0031] As Figure 1 shown, this embodiment provides a passive positioning device, which specifically includes:

[0032] A passive positioning tag, which receives a positioning signal of a first frequency sent by a detection device through a positioning antenna and transmits a feedback signal of a second frequency to the detection device according to the positioning signal of the first frequency, so that the detection device determines the position of the positioning tag according to the feedback signal of the second frequency;

[0033] A radio frequency tag is coupled to a reader through a radio frequency antenna. The radio frequency tag receives a carrier signal sent by the reader, generates an induced current according to the carrier signal, and sends encoded information to the reader.

[0034] Wherein, the absolute value of the difference between the frequency of the positioning antenna and the frequency of the radio frequency antenna is greater than or equal to a preset value.

[0035] Specifically, in this embodiment, a radio frequency tag is combined with a positioning tag to implement a passive positioning device that integrates long-distance position positioning and short-distance information acquisition and reading. Among them, both the positioning tag and the radio frequency tag adopt a passive design. The passive positioning tag combines the principle of whether a new frequency component is generated under microwave radiation by a nonlinear target with the radar technology of the detection device. The radio frequency tag is located in the far field area of the radiation field of the reader antenna. The radiation field of the reader antenna provides radio frequency energy for the radio frequency tag, and the radio frequency tag sends the encoded information to the reader to realize the communication between the reader and the tag.

[0036] More specifically, in this embodiment, the working principle of the passive positioning tag is that when the detection device emits a positioning signal, after the passive positioning tag receives the positioning signal, it will convert the first frequency of the positioning signal into a feedback signal of the second frequency and transmit the converted feedback signal to the detection device. The detection device emits at the first frequency and receives at the second frequency, so as to determine the position of the passive positioning tag according to the feedback signal. Among them, the first frequency of the positioning signal emitted by the detection device can be determined according to the radar power of the detection device and the search distance, and can be specifically adjusted according to the actual situation. For example, the detection device emits a fundamental wave f, and after being radiated by the nonlinear characteristics of the passive positioning tag, it emits a second harmonic 2f to the detection device. The detection device uses the fuzzy recognition algorithm and self-learning algorithm in the field of artificial intelligence to analyze and process the feedback signal, and gives the harmonic change law before and after the fundamental wave emission, so as to judge, identify and detect the passive positioning tag.

[0037] In addition, in the passive positioning tag of this embodiment, a nonlinear element is used for resonance, such as a diode, etc. After the positioning antenna is matched with the nonlinear element, it can provide sufficient power for subsequent frequency conversion and information transmission.

[0038] Existing passive positioning tags only have the positioning function and do not have functions such as information identification. Because the detection distance is far, it is technically impossible to effectively transmit information. Therefore, this embodiment combines a radio frequency tag on the basis of a passive positioning tag. Currently, existing radio frequency tags are divided into active tags, passive tags, and semi-active semi-passive tags according to the power supply method. Active tags require long-term power supply. The semi-active method is the battery method, which is inconvenient for long-term use and carrying. Passive tags solve the problems of power supply and long-distance communication and are easy to use. The radio frequency tag proposed in this embodiment is a passive tag.

[0039] Specifically, in this embodiment, the radio frequency tag and the card reader achieve non-contact coupling of radio frequency signals through a coupling element. In the coupling channel, according to the timing relationship, the transfer of energy and the exchange of data are realized. The coupling schematic diagram between the radio frequency tag and the card reader is as Figure 2 shown. Among them, the left side is the schematic diagram of the card reader circuit, and the right side is the schematic diagram of the radio frequency tag circuit. In this embodiment, the coupling of radio frequency signals between the radio frequency tag and the card reader mainly adopts inductive coupling. Based on the transformer model, the coupling is realized through the spatial high-frequency alternating magnetic field.

[0040] As Figure 2 shown, inductive coupling means that both the card reader antenna and the radio frequency tag antenna are closed coils, and data transmission is carried out through the inductive coupling between the two antennas. According to the law of electromagnetic induction, as long as the magnetic force lines (magnetic flux) passing through the coil change, an electromotive force will be induced in the coil. A coil will induce a self-induced electromotive force due to the change of its own current, which causes the change of the magnetic flux linking the coil. If there are two very close coils in the circuit, when a current passes through one coil, the magnetic force lines generated by this current not only pass through the coil itself, but also part of the magnetic force lines pass through the adjacent other coil. In this way, when the current changes, the magnetic force lines in the adjacent coil also change accordingly, thus inducing an electromotive force in the coil.

[0041] In this embodiment, the way for the radio frequency tag to identify information is that the card reader emits a signal to the radio frequency tag through the card reader antenna. The ASK debugging method and pulse interval coding can be adopted, as Figure 3 shown. The radio frequency tag in this embodiment may specifically include: a radio frequency antenna, a rectifying circuit, a micro switch, a radio frequency chip, a load modulation circuit, and a memory. As Figure 4 shown, a coupling element is arranged in the radio frequency antenna. This coupling element is used to sense the carrier signal emitted by the coupling element in the card reader antenna and generate an induced current. The induced current passes through the rectifying circuit and activates the micro switch to supply power to the radio frequency chip. The radio frequency chip transmits the encoded information stored in the memory to the card reader through the load modulation circuit according to the carrier signal by the radio frequency antenna.

[0042] The radio frequency tag within a certain frequency range receives the carrier signal emitted by the card reader. When the radio frequency antenna of the radio frequency tag receives a specific electromagnetic wave, an induced current will be generated in the coil. When the induced current passes through the rectifying circuit, the micro switch is activated to supply power to the radio frequency chip. The load modulation circuit of the radio frequency tag adopts the modulation methods of ASK and PSK to send the encoded information to the card reader, realizing two-way communication between the card reader and the radio frequency tag.

[0043] Based on the combination of the functions of passive positioning tags and RF tags, this embodiment uses independent antennas for the passive positioning tags and RF tags respectively. That is, the passive positioning device of this embodiment is provided with two antennas with different frequencies, and different functions are realized through different coupling methods. The principle of using independent antennas for the passive positioning tags and RF tags in this embodiment is that the frequency of the positioning antenna of the passive positioning tag is quite different from the frequency of the RF antenna of the RF tag, that is, the absolute value of the difference between the frequency of the positioning antenna and the frequency of the RF antenna is greater than or equal to a preset value. Usually, there is a certain difference between the RF antenna frequency of the RF tag for identity recognition and the positioning antenna frequency of the passive positioning tag for long-distance positioning. Generally, the RF antenna frequency of the RF tag is lower than the positioning antenna frequency of the passive positioning tag. When the RF antenna frequency of the RF tag and the positioning antenna frequency of the passive positioning tag show a large difference, it can be considered that the frequency of the positioning antenna of the passive positioning tag is quite different from the frequency of the RF antenna of the RF tag. According to the actual on-site situation, there will be a large fluctuation range in the frequency of the positioning antenna of the passive positioning tag and the frequency of the RF antenna of the RF tag in actual application. Therefore, the setting of the preset value used to calculate or judge the difference between the frequency of the positioning antenna and the frequency of the RF antenna can be adjusted according to the actual situation, and this embodiment does not make strict restrictions.

[0044] How to solve the mutual interference between different antennas, including frequency, power, and time-domain noise, during the combination of the functions of the two different tags is the technical difficulty of the passive positioning device proposed in this embodiment.

[0045] For the above technical difficulties, this embodiment needs to take isolation measures for the positioning antenna and the RF antenna. For example, a shielding layer made of shielding material can be set between the positioning antenna and the RF antenna to reduce the interference of external frequency bands. Another example is that filters can be added to the low-frequency antenna circuit to prevent high-frequency signals from entering the low-frequency antenna and causing damage to the tag chip. Another example is that according to the coupling method between the RF tag and the reader, the software can adopt an error correction coding method to improve the anti-interference ability of the communication system, so that a high communication quality can be maintained even in an interference environment.

[0046] For the isolation method of adding filters to the low-frequency antenna circuit, due to the addition of filters, the design difficulty of the matching circuit becomes more complex. In order to eliminate this influence, the matching circuit needs to be adjusted accordingly, and then the advantages of the shielding layer are used to make the functions of the passive positioning tag and the RF tag completely free from interference after combination.

[0047] Embodiment 2

[0048] As Figure 5 shown, this embodiment proposes a passive positioning device, which includes:

[0049] A passive positioning tag receives a positioning signal of a first frequency emitted by a detection device through a fundamental frequency antenna, and transmits a feedback signal of a second frequency to the detection device according to the positioning signal of the first frequency, so that the detection device determines the position of the positioning tag according to the feedback signal of the second frequency;

[0050] A radio frequency tag is coupled to a card reader through a fundamental frequency antenna. The radio frequency tag receives a carrier signal emitted by the card reader, generates an induced current according to the carrier signal, and transmits encoded information to the card reader;

[0051] A toggle switch, when in the initial position, the fundamental frequency antenna is connected to the passive positioning tag. After the passive positioning tag transmits a feedback signal to the detection device, the toggle switch switches positions, and the fundamental frequency antenna is connected to the radio frequency tag.

[0052] Specifically, the basic functions and working principles of the passive positioning tag and the radio frequency tag proposed in this embodiment can refer to the content recorded in Embodiment 1, and will not be elaborated here. The difference between the passive positioning device proposed in this embodiment and the passive positioning device proposed in Embodiment 1 is that the passive positioning tag and the radio frequency tag of the passive positioning device in this embodiment share an antenna, that is, the fundamental frequency antenna, and the functions of the passive positioning tag and the radio frequency tag are separated through circuit design.

[0053] Specifically, when the frequency of the positioning antenna required by the passive positioning tag is not much different from the frequency of the radio frequency antenna required by the radio frequency tag, that is, the absolute value of the difference between the frequency of the positioning antenna and the frequency of the radio frequency antenna is less than a preset value, this embodiment shares a fundamental frequency antenna for the passive positioning tag and the radio frequency tag, and designs a toggle switch to switch the connection states of the passive positioning tag and the radio frequency tag to the fundamental frequency antenna. When the radio frequency antenna frequency of the radio frequency tag approaches the positioning antenna frequency of the passive positioning tag, it can be considered that the frequency of the positioning antenna of the passive positioning tag is not much different from the frequency of the radio frequency antenna of the radio frequency tag. According to the actual on-site situation, the frequencies of the positioning antenna of the passive positioning tag and the radio frequency antenna of the radio frequency tag will have a large fluctuation range in actual application. Therefore, the setting of the preset value used to calculate or judge the difference between the frequency of the positioning antenna and the frequency of the radio frequency antenna can be adjusted according to the actual situation, and this embodiment does not make strict restrictions.

[0054] The fundamental frequency antenna can be custom-designed by simulating the high-frequency antenna and the impedance influence of the toggle switch. In the initial state, the toggle switch connects the fundamental frequency antenna in series with the passive positioning tag, so that the detection device can detect the passive positioning tag by detecting the extreme signal emitted by the fundamental frequency antenna, such as Figure 6As shown. After the detection device locates the passive positioning tag, the toggle switch changes its position, so that the fundamental frequency antenna is connected to the RF tag, as Figure 7 shown. After the card reader comes into close contact with the RF tag, inductive coupling can be carried out through the fundamental frequency antenna to generate energy for the RF chip, enabling the RF chip to work, so that the information inside the RF chip can be read through the card reader.

[0055] In the above process, the fundamental frequency antenna is relatively sensitive to factors such as peripheral impedance. When the detection device emits a fundamental frequency signal and is received by the fundamental frequency antenna, the peripheral environment of the passive positioning tag has a great impact on it, and the matching circuit of the RF tag and the RF chip will both interfere with the reflected echo. Therefore, the above impacts need to be considered when designing and simulating the fundamental frequency antenna. In addition, for the RF tag, after the toggle switch is switched to the RF tag, the matching circuit of the RF tag also needs to be further adjusted, and factors such as the impedance inside the RF chip need to be combined to enable the card reader to have sufficient energy to drive the RF chip and read the relevant encoded information.

[0056] Obviously, those skilled in the art can make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalent technologies, this application is also intended to include these changes and modifications.

Claims

1. A passive positioning device, characterized in that, The passive positioning device includes: A passive positioning tag that receives a positioning signal of a first frequency emitted by a detection device through a positioning antenna and transmits a feedback signal of a second frequency to the detection device according to the positioning signal of the first frequency, so that the detection device determines the position of the positioning tag according to the feedback signal of the second frequency; A radio frequency tag that is coupled to a card reader through a radio frequency antenna. The radio frequency tag receives a carrier signal emitted by the card reader, generates an induced current according to the carrier signal, and transmits encoded information to the card reader; Wherein, the absolute value of the difference between the frequency of the positioning antenna and the frequency of the radio frequency antenna is greater than or equal to a preset value.

2. The passive positioning device according to claim 1, wherein The first frequency is determined by the power of the detection device and the detection distance, and there is a multiple relationship between the first frequency and the second frequency.

3. The passive positioning device according to claim 1, characterized in that A filter is provided in the positioning antenna and / or the radio frequency antenna.

4. The passive positioning device according to claim 1, wherein A shielding layer is provided between the positioning antenna and the radio frequency antenna.

5. The passive positioning device according to claim 1, wherein A non-linear element for resonance is provided in the passive positioning tag.

6. The passive positioning device according to claim 1, characterized in that The radio frequency tag includes a radio frequency antenna, a rectifying circuit, a micro switch, a radio frequency chip, a load modulation circuit, and a memory. A coupling element is provided in the radio frequency antenna. The coupling element is used to sense a carrier signal emitted by a coupling element in the card reader antenna and generate an induced current. The induced current passes through the rectifying circuit and activates the micro switch to supply power to the radio frequency chip. The radio frequency chip transmits the encoded information stored in the memory from the radio frequency antenna to the card reader through the load modulation circuit according to the carrier signal.

7. The passive positioning device according to claim 6, wherein The radio frequency antenna and the card reader antenna are inductively coupled.

8. The passive positioning device according to claim 6, wherein The carrier signal uses ASK and PSK modulation methods to transmit the encoded information stored in the memory from the radio frequency antenna to the card reader through the load modulation circuit.

9. A passive positioning device, characterized in that, The passive positioning device includes: A passive positioning tag that receives a positioning signal of a first frequency emitted by a detection device through a fundamental frequency antenna and transmits a feedback signal of a second frequency to the detection device according to the positioning signal of the first frequency, so that the detection device determines the position of the positioning tag according to the feedback signal of the second frequency; A radio frequency tag that is coupled to a card reader through a fundamental frequency antenna. The radio frequency tag receives a carrier signal emitted by the card reader, generates an induced current according to the carrier signal, and transmits encoded information to the card reader; A toggle switch. When in the initial position, the fundamental frequency antenna is connected to the passive positioning tag. After the passive positioning tag transmits a feedback signal to the detection device, the toggle switch switches positions, and the fundamental frequency antenna is connected to the radio frequency tag.

10. The passive positioning device according to claim 9, wherein The fundamental frequency antenna and the card reader antenna are inductively coupled.

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