阅读说明：本技术 一种基于Wi-Fi信号的液体识别方法及装置 (Liquid identification method and device based on Wi-Fi signal ) 是由 李超 李凡 方滨兴 殷丽华 孙哲 罗熙 李丹 王星 于 2020-12-07 设计创作，主要内容包括：本发明公开了一种基于Wi－Fi信号的液体识别方法,包括：获取Wi－Fi信号发射器发射的Wi－Fi信号,并对所述Wi－Fi信号进行预处理操作,得到所述Wi－Fi信号的信道状态信息；将所述信道状态信息进行降噪处理,得到至少一组稳定的幅度比值和相位差值；将所述稳定的幅度比值和相位差值输入预先构建的数据库进行比对,判断出是否存在相同的数据,若是,则将液体识别的结果发送给用户终端；若否,则将所述稳定的幅度比值和相位差通过分类器,得到和所述幅度比值和相位差数据相似度最高的数据作为液体识别结果输出,并发送给用户终端。通过本发明,能够在在满足日常的液体识别需求的同时,降低液体的成本。(The invention discloses a liquid identification method based on Wi-Fi signals, which comprises the following steps: acquiring a Wi-Fi signal transmitted by a Wi-Fi signal transmitter, and preprocessing the Wi-Fi signal to obtain channel state information of the Wi-Fi signal; carrying out noise reduction processing on the channel state information to obtain at least one group of stable amplitude ratio and phase difference values; inputting the stable amplitude ratio and the phase difference value into a pre-constructed database for comparison, judging whether the same data exists or not, and if so, sending a liquid identification result to a user terminal; and if not, passing the stable amplitude ratio and the stable phase difference through a classifier to obtain data with the highest similarity to the amplitude ratio and the phase difference data, outputting the data as a liquid identification result, and sending the data to a user terminal. By the liquid identification device and the liquid identification method, the daily liquid identification requirement can be met, and the liquid cost is reduced.)

1. A liquid identification method based on Wi-Fi signals is characterized by comprising the following steps:

acquiring a Wi-Fi signal transmitted by a Wi-Fi signal transmitter, and preprocessing the Wi-Fi signal to obtain channel state information of the Wi-Fi signal; the Wi-Fi signals comprise Wi-Fi signals passing through the liquid to be detected and Wi-Fi signals not passing through the liquid to be detected;

carrying out noise reduction processing on the channel state information to obtain at least one group of stable amplitude ratio and phase difference values; the amplitude ratio and the phase difference value are the amplitude ratio and the phase difference value of Wi-Fi signal data passing through the liquid to be detected and Wi-Fi signal data not passing through the liquid to be detected;

inputting the stable amplitude ratio and the phase difference value into a pre-constructed database for comparison, judging whether the same data exists or not, and if so, sending a liquid identification result to a user terminal; and if not, passing the stable amplitude ratio and the stable phase difference through a classifier to obtain data with the highest similarity to the amplitude ratio and the phase difference data, outputting the data as a liquid identification result, and sending the data to a user terminal.

2. The Wi-Fi signal-based liquid identification method according to claim 1, wherein the pre-built database is specifically built as follows:

and measuring the amplitude ratio value and the phase difference value of various known liquids through the Wi-Fi signal, and storing the amplitude ratio value and the phase difference value in a database.

3. The Wi-Fi signal-based liquid identification method according to claim 1, wherein the Wi-Fi signal transmitted by the Wi-Fi signal transmitter is acquired and preprocessed to obtain channel state information of the Wi-Fi signal; the Wi-Fi signals comprise Wi-Fi signals passing through the liquid to be detected and Wi-Fi signals not passing through the liquid to be detected; the method specifically comprises the following steps:

firstly, a Wi-Fi signal transmitter controls a transmitting terminal antenna group to transmit Wi-Fi signals according to a control instruction, secondly, a Wi-Fi signal receiver receives the Wi-Fi signals from the Wi-Fi signal transmitter and transmits the Wi-Fi signals to a signal processing unit, and the signal processing unit converts the Wi-Fi signals into channel state information of the Wi-Fi signals.

4. The Wi-Fi signal-based liquid identification method according to claim 1, wherein the noise reduction processing method comprises: gaussian filtering method, kalman filtering method, and wavelet denoising method.

5. A Wi-Fi signal based liquid identification device, comprising: the device comprises an acquisition module, a data processing module and a judgment module; wherein the content of the first and second substances,

the acquisition module is used for acquiring a Wi-Fi signal transmitted by a Wi-Fi signal transmitter and carrying out preprocessing operation on the Wi-Fi signal to obtain channel state information of the Wi-Fi signal; the Wi-Fi signals comprise Wi-Fi signals passing through the liquid to be detected and Wi-Fi signals not passing through the liquid to be detected;

the data processing module is used for carrying out noise reduction processing on the channel state information to obtain at least one group of stable amplitude ratio and phase difference value; the amplitude ratio and the phase difference value are the amplitude ratio and the phase difference value of Wi-Fi signal data passing through the liquid to be detected and Wi-Fi signal data not passing through the liquid to be detected;

the judging module is used for inputting the stable amplitude ratio and the phase difference value into a pre-constructed database for comparison, judging whether the same data exists or not, and if so, sending a liquid identification result to a user terminal; and if not, passing the stable amplitude ratio and the stable phase difference through a classifier to obtain data with the highest similarity to the amplitude ratio and the phase difference data, outputting the data as a liquid identification result, and sending the data to a user terminal.

6. The Wi-Fi signal-based liquid identification device according to claim 5, wherein the pre-built database is built by the following steps:

and measuring the amplitude ratio value and the phase difference value of various known liquids through the Wi-Fi signal, and storing the amplitude ratio value and the phase difference value in a database.

7. The Wi-Fi signal-based liquid identification device according to claim 5, wherein the Wi-Fi signal transmitted by the Wi-Fi signal transmitter is acquired and preprocessed to obtain channel state information of the Wi-Fi signal; the Wi-Fi signals comprise Wi-Fi signals passing through the liquid to be detected and Wi-Fi signals not passing through the liquid to be detected; the method specifically comprises the following steps:

firstly, a Wi-Fi signal transmitter controls a transmitting terminal antenna group to transmit Wi-Fi signals according to a control instruction, secondly, a Wi-Fi signal receiver receives the Wi-Fi signals from the Wi-Fi signal transmitter and transmits the Wi-Fi signals to a signal processing unit, and the signal processing unit converts the Wi-Fi signals into channel state information of the Wi-Fi signals.

8. The Wi-Fi signal-based liquid identification device according to claim 5, wherein the noise reduction processing method comprises: gaussian filtering method, kalman filtering method, and wavelet denoising method.

9. A computer terminal device, comprising:

one or more processors;

a memory coupled to the processor for storing one or more programs;

the one or more programs, when executed by the one or more processors, cause the one or more processors to implement the Wi-Fi signal-based liquid identification method of any of claims 1-4.

10. A computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out a Wi-Fi signal based liquid identification method according to any one of claims 1 to 4.

Technical Field

The invention relates to the technical field of intelligent equipment material identification, in particular to a liquid identification method and device based on Wi-Fi signals.

Background

At present, the existing liquid identification methods mainly include the following methods, namely a spectroscopic analysis method, an electrical analysis method and a high-frequency electromagnetic wave (such as terahertz) measurement method. These methods are used in various instruments and constitute various liquid identification apparatuses. The method is the most common liquid identification method in a chemical laboratory, can detect trace substances, has high detection precision and mature technical development, and is mainly used for scientific research in the chemical laboratory at present; the electroanalysis method is characterized in that a special electrode is inserted into liquid, or liquid to be detected is dripped on the electrode, the conductivity and dielectric constant of the liquid or voltage or current change caused by response of certain special chemical sites on the electrode are detected, the liquid is identified, the detection precision can reach a trace level, and the electroanalysis method is currently applied to the fields of heavy metal ion detection, household blood glucose and blood lipid detection and the like; the high-frequency electromagnetic wave measurement method is a method for detecting by using a high-frequency electromagnetic wave transmitting antenna, a high-frequency electromagnetic wave receiving antenna and a signal processing circuit, performs liquid identification by detecting changes of electromagnetic wave signals, and is widely applied to the field of dangerous liquid detection at present.

However, the above-mentioned techniques have the following disadvantages:

the spectrum analysis method relies on expensive detection equipment, such as an infrared spectrometer, an ultraviolet-visible spectrophotometer and the like, and often needs to carry out detection in multiple modes together to determine the type of the liquid, the pretreatment process carried out before the detection is very complicated, the detection time is long, the detection cost is high, the equipment volume is large, and part of the detection equipment, such as a nuclear magnetic resonance spectrometer, even has certain harm to the bodies of detection personnel.

The electroanalytical method depends on equipment such as an electrochemical workstation or a blood glucose detector, one special electrode only corresponds to a few ions or molecules to be detected, the detection range is very limited, many electrodes are disposable electrodes and cannot be reused, and in addition, the electrode is required to be contacted with liquid in the measurement process, the operation is complex, and the liquid to be detected can be polluted.

The high-frequency electromagnetic wave measuring method relies on special equipment consisting of a high-frequency electromagnetic wave transmitting and receiving device and a signal processing circuit, such as a hazardous liquid detector and the like, is expensive, has single functions and low detection precision, can only carry out simple threshold value judgment, can distinguish aqueous solution and organic solution (hazardous liquid), preliminarily judges whether the liquid is flammable and explosive, but cannot identify the type of the liquid.

Disclosure of Invention

The purpose of the invention is: the liquid identification method and device based on the Wi-Fi signals are provided, and the cost of liquid can be reduced while the daily liquid identification requirement is met; the invention has low requirements on the performance and the computing power of the antenna and strong portability, and can be transplanted to any equipment with enough computing power and electromagnetic wave transceiving function.

In order to achieve the above object, the present invention provides a liquid identification method based on Wi-Fi signals, comprising: acquiring a Wi-Fi signal transmitted by a Wi-Fi signal transmitter, and preprocessing the Wi-Fi signal to obtain channel state information of the Wi-Fi signal; the Wi-Fi signals comprise Wi-Fi signals passing through the liquid to be detected and Wi-Fi signals not passing through the liquid to be detected;

carrying out noise reduction processing on the channel state information to obtain at least one group of stable amplitude ratio and phase difference values; the amplitude ratio and the phase difference value are the amplitude ratio and the phase difference value of Wi-Fi signal data passing through the liquid to be detected and Wi-Fi signal data not passing through the liquid to be detected;

inputting the stable amplitude ratio and the phase difference value into a pre-constructed database for comparison, judging whether the same data exists or not, and if so, sending a liquid identification result to a user terminal; and if not, passing the stable amplitude ratio and the stable phase difference through a classifier to obtain data with the highest similarity to the amplitude ratio and the phase difference data, outputting the data as a liquid identification result, and sending the data to a user terminal.

Further, the pre-constructed database is specifically constructed as follows: amplitude ratio values and phase difference values of various known liquids are measured through the Wi-Fi signals and stored in a database.

Further, the Wi-Fi signals transmitted by the Wi-Fi signal transmitter are obtained, and the Wi-Fi signals are preprocessed to obtain channel state information of the Wi-Fi signals; the Wi-Fi signals comprise Wi-Fi signals passing through the liquid to be detected and Wi-Fi signals not passing through the liquid to be detected; the method specifically comprises the following steps: firstly, a Wi-Fi signal transmitter controls a transmitting terminal antenna group to transmit Wi-Fi signals according to a control instruction, secondly, a Wi-Fi signal receiver receives the Wi-Fi signals from the Wi-Fi signal transmitter and transmits the Wi-Fi signals to a signal processing unit, and the signal processing unit converts the Wi-Fi signals into channel state information of the Wi-Fi signals.

Further, the noise reduction processing method includes: gaussian filtering method, kalman filtering method, and wavelet denoising method.

The embodiment of the invention also provides a liquid identification device based on Wi-Fi signals, which comprises: the device comprises an acquisition module, a data processing module and a judgment module; wherein the content of the first and second substances,

the acquisition module is used for acquiring a Wi-Fi signal transmitted by a Wi-Fi signal transmitter and preprocessing the Wi-Fi signal to obtain channel state information of the Wi-Fi signal; the Wi-Fi signals comprise Wi-Fi signals passing through the liquid to be detected and Wi-Fi signals not passing through the liquid to be detected;

the data processing module is used for carrying out noise reduction processing on the channel state information to obtain at least one group of stable amplitude ratio and phase difference value; the amplitude ratio and the phase difference value are the amplitude ratio and the phase difference value of Wi-Fi signal data passing through the liquid to be detected and Wi-Fi signal data not passing through the liquid to be detected;

the judging module is used for inputting the stable amplitude ratio and the phase difference value into a pre-constructed database for comparison, judging whether the same data exists or not, and if so, sending a liquid identification result to a user terminal; and if not, passing the stable amplitude ratio and the stable phase difference through a classifier to obtain data with the highest similarity to the amplitude ratio and the phase difference data, outputting the data as a liquid identification result, and sending the data to a user terminal.

Further, the pre-constructed database is specifically constructed as follows: and measuring the amplitude ratio value and the phase difference value of various known liquids through the Wi-Fi signal, and storing the amplitude ratio value and the phase difference value in a database.

Further, the Wi-Fi signals transmitted by the Wi-Fi signal transmitter are obtained, and the Wi-Fi signals are preprocessed to obtain channel state information of the Wi-Fi signals; the Wi-Fi signals comprise Wi-Fi signals passing through the liquid to be detected and Wi-Fi signals not passing through the liquid to be detected; the method specifically comprises the following steps: firstly, a Wi-Fi signal transmitter controls a transmitting terminal antenna group to transmit Wi-Fi signals according to a control instruction, secondly, a Wi-Fi signal receiver receives the Wi-Fi signals from the Wi-Fi signal transmitter and transmits the Wi-Fi signals to a signal processing unit, and the signal processing unit converts the Wi-Fi signals into channel state information of the Wi-Fi signals.

Further, the noise reduction processing method includes: gaussian filtering method, kalman filtering method, and wavelet denoising method.

An embodiment of the present invention further provides a computer terminal device, which is characterized by including:

one or more processors;

a memory coupled to the processor for storing one or more programs;

when executed by the one or more processors, cause the one or more processors to implement a Wi-Fi signal based liquid identification method as in any above.

An embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored, where the computer program is executed by a processor to implement the Wi-Fi signal-based liquid identification method according to any one of the above descriptions.

Compared with the prior art, the liquid identification method and device based on the Wi-Fi signal have the advantages that:

1) the liquid identification technology cost is reduced: by the invention, a user can identify the liquid in a Wi-Fi environment without spending thousands of elements or even tens of thousands of elements in a liquid identification technology. The invention has low requirements on the performance and the computing power of the antenna and strong portability, and can be transplanted to any equipment with enough computing power and electromagnetic wave transceiving function;

2) meet daily liquid identification demand: at present, people have demands on drink substance content detection and food safety detection in life, but no equipment capable of well solving the demands exists in the market.

Drawings

Fig. 1 is a schematic flowchart of a liquid identification method based on Wi-Fi signals according to a first embodiment of the present invention;

fig. 2 is a schematic overall architecture diagram of a Wi-Fi signal-based liquid identification method according to a first embodiment of the present invention;

FIG. 3 is a schematic deployment diagram of a Wi-Fi signal transmitting and receiving device of a liquid identification method based on Wi-Fi signals according to an embodiment of the present invention;

fig. 4 is a schematic overall deployment diagram of a measurement apparatus of a Wi-Fi signal-based liquid identification method according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of a liquid identification device based on Wi-Fi signals according to a second embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be understood that the step numbers used herein are for convenience of description only and are not intended as limitations on the order in which the steps are performed.

It is to be understood that the terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the specification of the present invention and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

The terms "comprises" and "comprising" indicate the presence of the described features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

The term "and/or" refers to and includes any and all possible combinations of one or more of the associated listed items.

The first embodiment of the present invention:

referring to fig. 1 to 4, a liquid identification method based on Wi-Fi signals according to an embodiment of the present invention at least includes the following steps:

s101, acquiring a Wi-Fi signal transmitted by a Wi-Fi signal transmitter, and preprocessing the Wi-Fi signal to obtain channel state information of the Wi-Fi signal; the Wi-Fi signals comprise Wi-Fi signals passing through the liquid to be detected and Wi-Fi signals not passing through the liquid to be detected;

it should be noted that, for step S101, the Wi-Fi signal transmitter and receiver structure and function are as follows:

1.1) transmitting end antenna group: is responsible for the emission of Wi-Fi signals. The antenna group at the transmitting end needs at least two antennas, the more the number of the antennas used in the antenna group is, the better the identification effect is, and each time one antenna is added or reduced, or other antennas at different positions are used, the new antenna array is adopted;

1.2) a signal transmitting module: and the system is responsible for receiving the instruction of the user terminal and generating a specified format of directional data packet to be transmitted. This module is completed by an on-chip Wi-Fi signal transmitter, which is a device that transmits Wi-Fi signals, including but not limited to Wi-Fi routers;

1.3) receiving end antenna group: is responsible for the reception of Wi-Fi signals. The receiving end antenna group needs at least one antenna, the more the number of the antennas used in the antenna group is, the better the identification effect is, and each time one antenna is increased or decreased, or other antennas in different positions are used, the new antenna array is adopted;

1.4) a signal receiving module: and the device is responsible for receiving the directional data packet with the specified format sent by the Wi-Fi signal transmitter. This module is completed by a chip in the Wi-Fi signal receiver, which is a device that receives Wi-Fi signals, including but not limited to a Wi-Fi router.

It should be noted that, for the liquid to be measured, the following conditions need to be satisfied:

2.1) position of liquid to be detected: the position of the liquid to be measured needs to be fixed, as shown in fig. 3, in this example, the position of the liquid to be measured should be as close to the receiving antenna 1 in the receiving end antenna group as possible, be away from the receiving antenna 2, and be located on the straight line connecting the receiving antenna 1 and the transmitting antenna, so as to ensure that the path from the receiving antenna 1 to the transmitting antenna passes through the liquid to be measured, and the path from the receiving antenna 2 to the transmitting antenna only passes through the air;

2.2) a liquid container to be tested: the liquid container to be detected is required to be a non-metal container, whether the liquid container is transparent or not can be determined, and the diameter of the liquid container is required to be determined;

2.3) liquid level to be detected: the liquid level cannot be too low and needs to exceed a specified liquid level according to different used equipment.

It should be noted that, for the preprocessing operation, the method includes:

3.1) data packet analysis: the data packet with the specified format obtained by the signal receiving module is analyzed into a channel state information packet;

3.2) extracting amplitude and phase: and processing the channel state information matrix in the channel state information packet into amplitude and phase information of electromagnetic waves, and sending the amplitude and phase information to the noise reduction module.

S102, carrying out noise reduction processing on the channel state information to obtain at least one group of stable amplitude ratio and phase difference values; the amplitude ratio and the phase difference value are the amplitude ratio and the phase difference value of Wi-Fi signal data passing through the liquid to be detected and Wi-Fi signal data not passing through the liquid to be detected;

it should be noted that, for the denoising process, methods such as gaussian filtering, kalman filtering, wavelet denoising, and the like are used to remove noise contained in the amplitude ratio and the phase difference, so as to obtain a stable amplitude ratio and a stable phase difference value, and send the values to the data processing module. The amplitude ratio and the phase difference are the amplitude ratio and the phase difference between electromagnetic wave signals passing through two paths of the transmitting antenna to the receiving antenna 1 and the receiving antenna 2, and because one path passes through the liquid to be detected and the other path only passes through the air between the two paths, the purpose of liquid identification is achieved by measuring the difference. In a similar way, by increasing the number of transmitting antennas and the number of receiving antennas, more sets of amplitude ratios and phase differences can be obtained, more sets of data for liquid identification can be obtained, and the identification accuracy can be improved.

S103, inputting the stable amplitude ratio and the phase difference value into a pre-constructed database for comparison, judging whether the same data exist or not, and if so, sending a liquid identification result to a user terminal; and if not, passing the stable amplitude ratio and the stable phase difference through a classifier to obtain data with the highest similarity to the amplitude ratio and the phase difference data, outputting the data as a liquid identification result, and sending the data to a user terminal.

Note that, for step S103, the database functions as follows: the liquid identification database is responsible for storing the existing liquid identification database, providing operation guidance for a user when the user accesses the liquid identification database, comparing the identification data packet and the information input by the user with the liquid identification database to obtain a corresponding liquid type as an identification result, generating feedback information and sending the feedback information to the user terminal. Each datum in the liquid identification database may consist of the following data items: the type of liquid, the type of equipment, the used router channel, the diameter of a container, the type of an antenna array, the distance between equipment, characteristic values corresponding to the antenna array and the like;

note that, for step S103, the classifier functions as follows: the classifier is obtained by training a liquid database of a cloud database, has the capacity of classifying unknown liquid, and can use classifiers with classification capacity such as GBDT, neural networks, support vector machines and the like. And when the comparison link of the cloud database is invalid, the most possible classification categories of the unknown liquid are obtained according to the existing liquid identification database result.

In an embodiment of the present invention, the pre-constructed database is specifically constructed as follows: and measuring the amplitude ratio value and the phase difference value of various known liquids through the Wi-Fi signal, and storing the amplitude ratio value and the phase difference value in a database.

In one embodiment of the present invention, the obtaining unit obtains a Wi-Fi signal transmitted by a Wi-Fi signal transmitter, and preprocesses the Wi-Fi signal to obtain channel state information of the Wi-Fi signal; the Wi-Fi signals comprise Wi-Fi signals passing through the liquid to be detected and Wi-Fi signals not passing through the liquid to be detected; the method specifically comprises the following steps: firstly, a Wi-Fi signal transmitter controls a transmitting terminal antenna group to transmit Wi-Fi signals according to a control instruction, secondly, a Wi-Fi signal receiver receives the Wi-Fi signals from the Wi-Fi signal transmitter and transmits the Wi-Fi signals to a signal processing unit, and the signal processing unit converts the Wi-Fi signals into channel state information of the Wi-Fi signals.

In an embodiment of the present invention, the noise reduction processing method includes: gaussian filtering method, kalman filtering method, and wavelet denoising method.

For the present embodiment, it can be specifically understood by the following examples:

as shown in fig. 4, the method is a specific embodiment of a liquid identification method based on Wi-Fi signals, a Wi-Fi signal transmitter and a Wi-Fi signal receiver are two Wi-Fi routers, signal processing, noise reduction and data processing are completed by one computer, and a user controls a terminal of a smart phone to start identifying unknown liquid after putting liquid to be detected as required through operation prompt of the smart phone, and finally obtains an identification result on a screen of the smart phone. The specific process of application is as follows:

1. the user uses the smart phone access system, and the cloud database sends operation instructions to the smart phone and displays the operation instructions to the user on a screen;

2. a user places a container filled with liquid to be detected at a designated position according to operation instructions;

3. a user inputs information such as the selected antenna array type, the container diameter, the router spacing and the like in the smart phone, the information is sent to a cloud-end database for next processing, and the user sends a measurement starting instruction to a router at a sending end;

4. the receiving end router receives the data packet containing the information and sends the data packet to a signal processing module on a computer. Here, if the performance of the router is enough, the router chip can replace the whole work of the computer;

5. after receiving the data packet, the computer converts the data packet into channel state information of an electromagnetic wave signal, performs noise reduction processing on the channel state information to obtain a stable amplitude ratio and a stable phase difference, inputs the channel state information into a data processing module of the computer, calculates a required dielectric constant value and a required conductivity value, integrates the router model, the dielectric constant value and the conductivity value corresponding to the used router channel and the antenna array and the like into an identification data packet, and sends the identification data packet to a cloud database;

6. after receiving user input information and an identification data packet, the cloud database integrates the two pieces of information and compares the two pieces of information with the liquid identification database to judge whether the same data is input or not, if so, corresponding liquid types are obtained as identification results, feedback information is generated and sent to the user terminal, and if not, a classifier is used and the classification results are fed back to the user terminal;

7. and the smart phone of the user receives the identification result finally fed back by the cloud and displays the result to the user on the screen of the smart phone.

Compared with the prior art, the liquid identification method based on the Wi-Fi signal of the embodiment of the invention,

firstly, through the invention, a user can identify the liquid in a Wi-Fi environment without spending thousands of elements or even tens of thousands of elements in the liquid identification technology. The invention has low requirements on the performance and the computing power of the antenna and strong portability, and can be transplanted to any equipment with enough computing power and electromagnetic wave transceiving function;

secondly, due to the fact that at present, people have requirements for detecting the content of drink substances and detecting food safety in life, but no equipment capable of well solving the requirements exists in the market, sellers can update existing equipment such as a router, a smart phone, a computer and the like through the liquid identification method and device, liquid identification can be carried out in a Wi-Fi environment, identification accuracy is improved compared with that of the existing liquid identification equipment at the thousand yuan level, and daily liquid identification requirements of people are met.

Second embodiment of the invention:

referring to fig. 5, an embodiment of the invention provides a liquid identification apparatus 200 based on Wi-Fi signals, including: an acquisition module 201, a data processing module 202 and a judgment module 203; wherein the content of the first and second substances,

the acquisition module 201 is configured to acquire a Wi-Fi signal transmitted by a Wi-Fi signal transmitter, and perform a preprocessing operation on the Wi-Fi signal to obtain channel state information of the Wi-Fi signal; the Wi-Fi signals comprise Wi-Fi signals passing through the liquid to be detected and Wi-Fi signals not passing through the liquid to be detected;

the data processing module 202 is configured to perform noise reduction processing on the channel state information to obtain at least one group of stable amplitude ratio and phase difference; the amplitude ratio and the phase difference value are the amplitude ratio and the phase difference value of Wi-Fi signal data passing through the liquid to be detected and Wi-Fi signal data not passing through the liquid to be detected;

the judging module 203 is configured to input the stable amplitude ratio and the phase difference value into a pre-constructed database for comparison, judge whether the same data exists, and send a liquid identification result to the user terminal if the same data exists; and if not, passing the stable amplitude ratio and the stable phase difference through a classifier to obtain data with the highest similarity to the amplitude ratio and the phase difference data, outputting the data as a liquid identification result, and sending the data to a user terminal.

In an embodiment of the present invention, the pre-constructed database is specifically constructed as follows: and measuring the amplitude ratio value and the phase difference value of various known liquids through the Wi-Fi signal, and storing the amplitude ratio value and the phase difference value in a database.

In one embodiment of the present invention, the obtaining unit obtains a Wi-Fi signal transmitted by a Wi-Fi signal transmitter, and preprocesses the Wi-Fi signal to obtain channel state information of the Wi-Fi signal; the Wi-Fi signals comprise Wi-Fi signals passing through the liquid to be detected and Wi-Fi signals not passing through the liquid to be detected; the method specifically comprises the following steps: firstly, a Wi-Fi signal transmitter controls a transmitting terminal antenna group to transmit Wi-Fi signals according to a control instruction, secondly, a Wi-Fi signal receiver receives the Wi-Fi signals from the Wi-Fi signal transmitter and transmits the Wi-Fi signals to a signal processing unit, and the signal processing unit converts the Wi-Fi signals into channel state information of the Wi-Fi signals.

In an embodiment of the present invention, the noise reduction processing method includes: gaussian filtering method, kalman filtering method, and wavelet denoising method.

Third embodiment of the invention:

the embodiment of the invention provides computer terminal equipment, which comprises one or more processors; a memory coupled to the processor for storing one or more programs; when executed by the one or more processors, cause the one or more processors to implement a Wi-Fi signal based liquid identification method as in any above.

The fourth embodiment of the present invention:

an embodiment of the present invention provides a computer-readable storage medium, on which a computer program is stored, where the computer program, when executed by a processor, implements the Wi-Fi signal-based liquid identification method according to any one of the above descriptions.

In conclusion, the liquid identification method and the liquid identification device can meet daily liquid identification requirements and reduce liquid cost. The invention has low requirements on the performance and the computing power of the antenna and strong portability, and can be transplanted to any equipment with enough computing power and electromagnetic wave transceiving function.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and substitutions can be made without departing from the technical principle of the present invention, and these modifications and substitutions should also be regarded as the protection scope of the present invention.