Wireless electromagnetic environment data acquisition and positioning device and method based on UWB backscattering

Abstract

The invention relates to a wireless electromagnetic environment data acquisition and positioning device and method based on UWB backscattering. The device comprises a reader and a passive tag, the reader sends an energy supply signal to wake up the passive tag in a UHF RFID time slot stage, enters a dormancy state after entering a data acquisition time slot stage, sends a UWB frequency band pulse signal to the passive tag in a UWB communication time slot stage, and completes positioning of the passive tag after receiving a signal reflected and scattered by the passive tag; the passive tag enters a data acquisition time slot stage after being awakened by the reader, acquires electromagnetic field data, transmits the acquired data back to the reader, receives a UWB frequency band pulse signal sent by the reader in a UWB communication time slot stage for backscattering, and modulates the signal by changing the impedance of an antenna. According to the invention, a time division multiplexing method is adopted to realize multi-node inquiry, so that more efficient reading is realized, and centimeter-level positioning precision is realized by using UWB signals.

Description

Technical Field

[0001] The present invention relates to the field of radio, and particularly to a wireless electromagnetic environment data acquisition and positioning device and method based on UWB backscattering. Background Art

[0002] With the rapid development of radio technology, the electromagnetic environment in space is becoming increasingly complex, and the acquisition of electromagnetic environment data faces new requirements and challenges. In industrial production scenarios, it is necessary to collect and monitor the electromagnetic environment data in the workshop. Due to the small attachment area of the acquisition device and the low load-bearing capacity of the attached carrier, there are requirements for lightweight and low-cost electromagnetic environment detection devices; at the same time, due to the high utilization rate of the electromagnetic spectrum and the complex electromagnetic environment in the environment, there are requirements for multi-node and locatable electromagnetic environment monitoring devices.

[0003] However, from the perspective of perception, the existing traditional electromagnetic field strength meter instruments are heavy and large in size, and do not meet the requirements of portability; from the perspective of multi-node scalability, the common electromagnetic field monitoring devices are single-node detections and do not meet the requirements of scalability; from the perspective of positioning, the traditional electromagnetic field monitoring instruments cannot obtain the position information of the nodes and do not meet the requirements of high-precision positioning; in addition, in the interrogation and response system of RFID, collisions are likely to occur between passive tags, resulting in low multi-node interrogation efficiency. At the same time, the positioning accuracy of the RFID communication method is relatively low. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art, and provides a wireless electromagnetic environment data acquisition and positioning device and method based on UWB backscattering, which solves the deficiencies existing in the prior art.

[0005] The purpose of the present invention is achieved through the following technical solutions: A wireless electromagnetic environment data acquisition and positioning device based on UWB backscattering, which includes a backscattering architecture jointly composed of a reader and a passive tag;

[0006] The reader sends an energizing signal in the UHF RFID time slot stage to wake up the passive tag, enters the sleep state after entering the data acquisition time slot stage, finally sends a pulse signal in the UWB communication time slot stage to the passive tag on the UWB frequency band, and completes the positioning of the passive tag after receiving the signal reflected and scattered by the passive tag;

[0007] The passive tag enters the data acquisition time slot stage after being woken up by the reader, collects the electromagnetic field data, and transmits the collected data back to the reader. Finally, in the UWB communication time slot stage, it receives the pulse signal sent by the reader on the UWB frequency band for backscattering, and modulates the signal by changing the impedance of the antenna.

[0008] The reader includes a ZYNQ development board and a radio frequency development board; after the signal generated by the transmitting link of the reader is encoded and modulated, it is transmitted after being converted by the DA of the radio frequency development board.

[0009] Then, the receiving link receives the signal, separates and extracts the received signal through the radio frequency development board, demodulates the signal into a baseband signal, the ZYNQ development board performs clock recovery and symbol decision on the signal, checks and corrects the received signal code according to the communication protocol adopted by the transceiver, restores the original passive tag backscatter signal, and decodes the data information contained in the signal to realize the identification and reading of the passive tag.

[0010] The passive tag includes a power acquisition module, a UHF link demodulation module, an electromagnetic environment data acquisition module, and a UWB impedance modulation module;

[0011] The UHF antenna is connected to the power acquisition module and the UHF link demodulation module through a radio frequency switch. In the power acquisition link, after the energy supply signal is received by the UHF antenna, a stable voltage signal is obtained through the power acquisition module to supply power to the electromagnetic environment data acquisition module and the UWB impedance modulation module.

[0012] The UHF link demodulation module is connected to the electromagnetic environment data acquisition module and outputs digital 0 / 1 signals to the electromagnetic data acquisition module to decode the signals.

[0013] The electromagnetic environment data acquisition module is connected to the environmental data acquisition antenna, realizes the acquisition of the electromagnetic field in the data acquisition link, and controls the radio frequency switch to realize the backscattering of the electromagnetic environment sensing data.

[0014] The UWB impedance modulation module is connected to the UWB antenna and performs impedance modulation on the UWB pulse signal received by the passive tag by changing the impedance loaded on the UWB antenna.

[0015] The power acquisition module includes a rectifier, a DC-DC boost module, and a voltage stabilization module connected in sequence. After the energy supply signal is received by the UHF antenna, a DC signal is obtained through the rectifier and given to the DC-DC boost module to convert the rectified voltage into a stable voltage signal, and then the voltage stabilization module outputs the voltage values for the electromagnetic environment data acquisition module and the UWB impedance modulation module.

[0016] The UHF link demodulation module includes a diode and a comparator. The diode performs envelope detection on the received signal, and then a digital 0 / 1 signal is obtained through the comparator and given to the electromagnetic environment data acquisition module to decode the signal.

[0017] The electromagnetic environment data acquisition module includes an MCU with an internal ADC and a power detector; the power detector acquires electromagnetic field data and converts it into an amplitude signal, the ADC performs AD conversion on the amplitude signal to obtain a digital signal of the field strength, and the MCU controls the RF switch to load the sensing digital signal onto the RF switch, realizing the backscattering of the sensing digital signal.

[0018] The UWB impedance modulation module includes a UWB switch and a crystal oscillator. The MCU controls the UWB switch through the crystal oscillator, and by changing the impedance loaded on the UWB antenna, impedance modulation is performed on the UWB pulse signal received by the passive tag.

[0019] A wireless electromagnetic environment data acquisition and positioning method based on UWB backscattering, the method includes:

[0020] Wake-up step: In the UHF RFID time slot stage, the reader emits an energy supply signal in the UHF band for the passive tag to collect energy. When the energy collected by the passive tag meets the voltage required to provide the operation of the passive tag, the tag is woken up. After the reader sends an inquiry command and identifies the target passive tag, the reader sends a collection command to the low-power MCU in the passive tag;

[0021] Data acquisition step: Enter the data acquisition time slot stage. At this time, the reader enters the sleep state, and the MCU in the passive tag controls the electromagnetic environment data acquisition module to collect electromagnetic field data, and then transmits the collected data back to the reader;

[0022] Backscattering step: In the UWB communication time slot stage, the reader sends a pulse signal in the UWB band. After the passive tag receives the pulse signal, it performs backscattering on the pulse signal and reflects the signal back to the reader, and the reader completes the positioning of the passive tag.

[0023] The present invention has the following advantages: A wireless electromagnetic environment data acquisition and positioning device and method based on UWB backscattering adopts a time division multiplexing method to realize multi-node inquiry, and thus realizes more efficient reading, and uses UWB signals to achieve centimeter-level positioning accuracy. Description of the Drawings

[0024] Figure 1 It is a schematic structural diagram of the reader of the present invention;

[0025] Figure 2 It is a schematic structural diagram of the passive tag of the present invention. Detailed Embodiments

[0026] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only some of the embodiments of this application, rather than all of them. The components of the embodiments of this application usually described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations. Therefore, the detailed description of the embodiments of this application provided below with reference to the accompanying drawings is not intended to limit the protection scope of this application that is claimed, but only represents the selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative efforts fall within the protection scope of this application. The following further describes the present invention with reference to the accompanying drawings.

[0027] One implementation of the present invention relates to a wireless electromagnetic environment data acquisition and positioning device based on UWB backscattering, which includes a backscattering architecture jointly composed of a reader and a passive tag;

[0028] Among them, the reader sends an energizing signal during the UHF RFID time slot stage to wake up the passive tag, enters the sleep state after entering the data acquisition time slot stage, and finally sends a pulse signal in the UWB frequency band to the passive tag during the UWB communication time slot stage, and completes the positioning of the passive tag after receiving the signal reflected and scattered by the passive tag;

[0029] After being woken up by the reader, the passive tag enters the data acquisition time slot stage, collects electromagnetic field data, and transmits the collected data back to the reader. Finally, during the UWB communication time slot stage, it receives the pulse signal in the UWB frequency band sent by the reader for backscattering, and modulates the signal by changing the impedance of the antenna.

[0030] The backscattering of the antenna consists of two parts: the structural mode and the antenna mode. The structural mode is related to the shape, size, and material of the antenna, and the antenna mode is related to the antenna radiation characteristics and the antenna load, and can be modulated in the passive backscattering system.

[0031] For an antenna with a frequency-dependent given angle and load, its backscattering transfer function Among them, the left half of the left side of the equation represents the structural mode, and the right half represents the antenna mode. The antenna mode is related to the load reflection coefficient Γ L , the antenna reflection coefficient S 11 and the realized gain |S 1ξ S ξ1 |. When the load impedance of the antenna is equal to the reference impedance, only the reflection of the structural mode exists. When the antenna is well-matched (S 11 is very small), the load is short-circuited (Γ L= -1) and the antenna pattern under load open circuit (Γ L is opposite to that under load open circuit (Γ = 1). Therefore, by means of a switch chip, the load impedance of the antenna is adjusted by controlling the on / off of the switch chip, the reflection mode of the antenna can be changed, and the reflection of signals with different amplitudes can be achieved, that is, amplitude modulation of signals is realized.

[0032] As Figure 1 shown, the reader includes a ZYNQ development board integrating an FPGA chip and an ARM chip and an AD9361 radio frequency development board; the signal generated by the transmitting link of the reader is encoded and modulated by PIE, and then transmitted through the DA conversion of the radio frequency development board.

[0033] Then the signal is received by the receiving link, the received signal is separated and extracted by the radio frequency development board, and the signal is demodulated into a baseband signal by FMO or Miller. With the high-speed computing ability of the FPGA, the signal is clock recovered and symbol judged, and the received signal code is verified and corrected according to the communication protocol adopted by the transceiver, and the original passive tag backscattered signal is recovered, and the data information contained in the decoded signal (such as the EPC code of the tag, the data stored in the tag, etc.) is decoded, so as to realize the identification and reading of the passive tag.

[0034] As Figure 2 shown, the passive tag includes a power collection module, a UHF link demodulation module, an electromagnetic environment data collection module and a UWB impedance modulation module;

[0035] Among them, the UHF antenna is connected to the power collection module and the UHF link demodulation module through a radio frequency switch. In the power collection link, the energy supply signal is received by the UHF antenna and then a stable voltage signal is obtained through the power collection module to supply power to the electromagnetic environment data collection module and the UWB impedance modulation module;

[0036] The UHF link demodulation module is connected to the electromagnetic environment data collection module, and outputs a digital 0 / 1 signal to the electromagnetic data collection module to decode the signal;

[0037] The electromagnetic environment data collection module is connected to the environmental data collection antenna, realizes the collection of the electromagnetic field in the data collection link, and controls the radio frequency switch to realize the backscattering of the electromagnetic environment sensing data;

[0038] The UWB impedance modulation module is connected to the UWB antenna, and impedance modulation is performed on the UWB pulse signal received by the passive tag by changing the impedance loaded on the UWB antenna.

[0039] Further, the power acquisition module includes a rectifier, a DC-DC boost module, and a voltage regulation module connected in sequence. After the energy supply signal is received by the UHF antenna, a DC signal is obtained through the rectifier and given to the DC-DC boost module to convert the rectified voltage into a stable voltage signal. Then, the voltage regulation module outputs the voltage value for the electromagnetic environment data acquisition module and the UWB impedance modulation module.

[0040] The UHF link demodulation module includes a diode and a comparator. The diode performs envelope detection on the received signal, and then a digital 0 / 1 signal is obtained through the comparator and given to the electromagnetic environment data acquisition module to decode the signal.

[0041] The electromagnetic environment data acquisition module includes an MCU with an ADC integrated inside and a power detector; the power detector collects the electromagnetic field data and converts it into an amplitude signal, the ADC performs AD conversion on the amplitude signal to obtain the digital signal of the field strength, and the MCU controls the RF switch to load the sensing digital signal onto the RF switch to achieve the backscattering of the sensing digital signal.

[0042] The UWB impedance modulation module includes a UWB switch and a crystal oscillator. The MCU controls the UWB switch through the crystal oscillator and modulates the impedance of the UWB pulse signal received by the passive tag by changing the impedance loaded on the UWB antenna.

[0043] Another embodiment of the present invention relates to a wireless electromagnetic environment data acquisition and positioning method based on UWB backscattering. The method includes:

[0044] Wake-up step: In the UHF RFID time slot stage, the reader emits an energy supply signal in the UHF band for the passive tag to perform energy acquisition. When the energy collected by the passive tag meets the voltage required to provide the operation of the passive tag, the tag is woken up. After the reader sends an inquiry command and identifies the target passive tag, the reader sends an acquisition command to the low-power MCU in the passive tag;

[0045] Data acquisition step: Enter the data acquisition time slot stage. At this time, the reader enters the sleep state, and the MCU in the passive tag controls the electromagnetic environment data acquisition module to collect the electromagnetic field data and then transmits the collected data back to the reader;

[0046] Backscattering step: In the UWB communication time slot stage, the reader sends a pulse signal in the UWB band. After the passive tag receives the pulse signal, it performs backscattering on the pulse signal and reflects the signal back to the reader, and the reader completes the positioning of the passive tag.

[0047] The above are only the preferred embodiments of the present invention. It should be understood that the present invention is not limited to the forms disclosed herein, and should not be regarded as excluding other embodiments. Instead, it can be used in various other combinations, modifications, and improvements, and can be changed within the scope of the concept described herein through the above teachings or the techniques or knowledge in the relevant field. As long as the changes and variations made by those skilled in the art do not depart from the spirit and scope of the present invention, they should all be within the protection scope of the appended claims of the present invention.

Claims

1. A wireless electromagnetic environment data acquisition and positioning device based on UWB backscattering, characterized in that: It includes a backscattering architecture jointly composed of a reader and a passive tag; The reader sends an energizing signal to wake up the passive tag during the UHF RFID time slot phase, enters the sleep state after entering the data acquisition time slot phase, and finally sends a pulse signal in the UWB communication time slot phase to the passive tag, and completes the positioning of the passive tag after receiving the signal reflected and scattered by the passive tag; After being awakened by the reader, the passive tag enters the data acquisition time slot phase, collects electromagnetic field data, and transmits the collected data back to the reader. Finally, in the UWB communication time slot phase, it receives the pulse signal in the UWB frequency band sent by the reader for backscattering, and modulates the signal by changing the impedance of the antenna.

2. The wireless electromagnetic environment data acquisition and positioning device based on UWB backscattering according to claim 1, characterized in that: The reader includes a ZYNQ development board and a radio frequency development board; the signal generated by the transmitting link of the reader is encoded and modulated, and then transmitted through the DA conversion of the radio frequency development board. Then the receiving link receives the signal, separates and extracts the received signal through the radio frequency development board, and demodulates the signal into a baseband signal. The ZYNQ development board performs clock recovery and symbol decision on the signal, checks and corrects the received signal code according to the communication protocol adopted by the transceiver, restores the original passive tag backscattered signal, decodes the data information contained in the signal, and realizes the identification and reading of the passive tag.

3. The wireless electromagnetic environment data acquisition and positioning device based on UWB backscattering according to claim 1, wherein: The passive tag includes a power acquisition module, a UHF link demodulation module, an electromagnetic environment data acquisition module, and a UWB impedance modulation module; The UHF antenna is connected to the power acquisition module and the UHF link demodulation module through a radio frequency switch. In the power acquisition link, the energizing signal is received by the UHF antenna and then a stable voltage signal is obtained through the power acquisition module to supply power to the electromagnetic environment data acquisition module and the UWB impedance modulation module; The UHF link demodulation module is connected to the electromagnetic environment data acquisition module and outputs a digital 0 / 1 signal to the electromagnetic data acquisition module to decode the signal; The electromagnetic environment data acquisition module is connected to the environmental data acquisition antenna, realizes the acquisition of the electromagnetic field during the data acquisition link, and controls the radio frequency switch to realize the backscattering of the electromagnetic environment sensing data; The UWB impedance modulation module is connected to the UWB antenna and performs impedance modulation on the UWB pulse signal received by the passive tag by changing the impedance loaded on the UWB antenna.

4. The wireless electromagnetic environment data acquisition and positioning device based on UWB backscattering according to claim 3, wherein: The power acquisition module includes a rectifier, a DC-DC boost module, and a voltage stabilization module connected in sequence. After the energizing signal is received by the UHF antenna, a DC signal is obtained through the rectifier and given to the DC-DC boost module to convert the rectified voltage into a stable voltage signal, and then the voltage stabilization module outputs the voltage values for the electromagnetic environment data acquisition module and the UWB impedance modulation module.

5. The wireless electromagnetic environment data acquisition and positioning device based on UWB backscattering according to claim 3, wherein: The UHF link demodulation module includes a diode and a comparator. The diode performs envelope detection on the received signal, and then a digital 0 / 1 signal is obtained through the comparator and given to the electromagnetic environment data acquisition module to decode the signal.

6. The wireless electromagnetic environment data acquisition and positioning device based on UWB backscattering according to claim 3, characterized in that: The electromagnetic environment data acquisition module includes an MCU with an internal integrated ADC and a power detector; the power detector acquires electromagnetic field data and converts it into an amplitude signal, the ADC performs AD conversion on the amplitude signal to obtain a digital signal of the field strength, and the MCU controls the RF switch to load the sensing digital signal onto the RF switch to achieve backscattering of the sensing digital signal.

7. The wireless electromagnetic environment data acquisition and positioning device based on UWB backscattering according to claim 6, characterized in that: The UWB impedance modulation module includes a UWB switch and a crystal oscillator. The MCU controls the UWB switch through the crystal oscillator, and impedance-modulates the UWB pulse signal received by the passive tag by changing the impedance loaded on the UWB antenna.

8. A method for collecting and positioning wireless electromagnetic environment data based on UWB backscattering, characterized in that: The method includes: Wake-up step: In the UHF RFID time slot phase, the reader emits an energy supply signal in the UHF band for the passive tag to perform energy acquisition. When the energy acquired by the passive tag meets the voltage required to power the passive tag, the tag is woken up. After the reader sends an interrogation command and identifies the target passive tag, the reader sends a collection command to the low-power MCU in the passive tag. Data acquisition step: Enter the data acquisition time slot phase. At this time, the reader goes into sleep, and the MCU in the passive tag controls the electromagnetic environment data acquisition module to acquire electromagnetic field data and then transmits the acquired data back to the reader. Backscattering step: In the UWB communication time slot phase, the reader sends a pulse signal in the UWB band. After the passive tag receives the pulse signal, it backscatters the pulse signal and reflects the signal back to the reader, and the reader completes the positioning of the passive tag.

Images