阅读说明：本技术 一种电子鼻、气味识别方法及存储介质 (Electronic nose, smell identification method and storage medium ) 是由 陶晓彥 李芳� 万晓春 于 2019-09-02 设计创作，主要内容包括：本发明公开了一种电子鼻、气味识别方法及存储介质,其中,电子鼻包括：气流通道、传感器阵列及气流控制件,所述传感器阵列位于所述气流通道内,气流控制件用于将气流通道内的待检测气体吹出。基于此,本发明所提供的电子鼻可净化气流通道,防止传感器疲劳以及气流通道内残留气体对后续气体检测结果产生影响,改善了现有技术中电子鼻在长时间使用时,会由于进气管内气体混杂,导致测量结果不精确的问题。(The invention discloses an electronic nose, a smell identification method and a storage medium, wherein the electronic nose comprises: the gas detection device comprises a gas flow channel, a sensor array and a gas flow control piece, wherein the sensor array is positioned in the gas flow channel, and the gas flow control piece is used for blowing out gas to be detected in the gas flow channel. Therefore, the electronic nose provided by the invention can purify the air flow channel, prevents the sensor from fatigue and prevents residual gas in the air flow channel from influencing the subsequent gas detection result, and solves the problem that the measurement result is inaccurate due to the mixing of gas in the air inlet pipe when the electronic nose is used for a long time in the prior art.)

1. An electronic nose comprising: the sensor array is positioned in the airflow channel; characterized in that, the electron nose still includes: and the air flow control part is used for blowing out the gas to be detected in the air flow channel.

2. The electronic nose according to claim 1, wherein the airflow control member has two states of inhaling and exhausting, and the gas to be detected is introduced into the airflow channel when inhaling, and the gas to be detected in the airflow channel is blown out when exhausting.

3. The electronic nose according to claim 2, wherein a wall of the airflow channel is undulated.

4. The electronic nose of claim 3, wherein the sensor array is located at a top end wall portion of the airflow passage.

5. The electronic nose according to claim 1, wherein the airflow control member is a fan or an air pump, and the air volume of the airflow control member is between 10CFM and 50 CFM.

6. The electronic nose according to claim 5, wherein the airflow control member has an airflow rate of 35 CFM.

7. An odor recognition method, implemented based on the electronic nose according to any one of claims 1 to 6, comprising:

training sample learning is carried out by utilizing a chaos optimization algorithm;

gas to be detected enters the gas flow channel;

the sensor array senses the gas to be detected and outputs a signal according to a sensing result;

the pattern recognition application program recognizes the gas composition from the signals output by the sensor array;

the air flow control part blows out the gas to be detected in the air flow channel;

the sensor array continues to sense new sensing gas entering the gas flow path until the task is completed.

8. The scent recognition method of claim 7 wherein the step of training sample learning using a chaotic optimization algorithm specifically comprises:

initializing a network weight by using a chaotic algorithm;

reading a set of training samples;

calculating output values of each layer of the network;

calculating errors between the output values;

and judging whether the calculated error is smaller than a preset threshold value, if so, continuing to read the next group of training samples until the reading of the training samples is finished.

9. The method for odor recognition according to claim 8, wherein the step of determining whether the calculated error is smaller than a preset threshold, and if so, continuing to read the next set of training samples until the end of the reading of the training samples further comprises: if not, calculating local gradients of each layer of the network, adding a chaotic nonlinear operator, and updating the weight of the network.

10. A storage medium having stored thereon a computer program, characterized in that the computer program, when being executed by a processor, carries out the steps of the scent recognition method according to any one of claims 7 to 9.

Technical Field

The invention relates to the technical field of odor identification devices and methods, in particular to an electronic nose, an odor identification method and a storage medium.

Background

The electronic nose is an electronic system for recognizing odor using response patterns of a gas sensor array, which can continuously monitor odor conditions of a specific location in real time for a period of hours, days, or even months.

The electronic nose mainly comprises three functional devices, namely an odor sampling operator, a gas sensor array and a signal processing system. The main mechanism of the electronic nose for recognizing the odor is that each sensor in the array has different sensitivity to the gas to be detected, for example, the first gas can generate high response on one sensor, and low response on other sensors, and similarly, the second gas generates high response and is not sensitive to the first gas, and after all, the response patterns of the whole sensor array to different gases are different, so that the system can recognize the odor according to the response patterns of the sensors.

The core device of the electronic nose is a gas sensor, and the gas sensor can be divided into a plurality of types such as a metal oxide type, an electrochemical type, a conductive polymer type, a mass type, a photoionization type and the like according to different principles. The most widely used at present are the metal oxide types.

As shown in fig. 1, fig. 2 and fig. 3, the conventional electronic nose generally includes an electronic nose main body 1, the electronic nose main body 1 includes an upper cover 2 and a lower shell 7, the upper cover 2 is located above the lower shell 7, a power switch 3 is disposed on a position close to one side of a front end outer surface of the lower shell 7, an air inlet pipe 4 is disposed on a position close to the other side of the front end outer surface of the lower shell 7, a pressurized hand-held ball 5 is fixedly mounted on a position close to one side of a rear end of the lower shell 7, a guide groove 8 is horizontally mounted on an upper end surface of the lower shell 7 close to two sides, guide rails 13 are fixedly mounted on lower surfaces of two sides of the upper cover 2, the upper cover 2 is horizontally slidably connected with the.

When the existing electronic nose is used for a long time, the measurement result is inaccurate due to the fact that gas in the air inlet pipe is mixed.

It can be seen that the prior art is still in need of improvement and development.

Disclosure of Invention

In view of the above-mentioned shortcomings of the prior art, the present invention provides an electronic nose, an odor recognition method and a storage medium, which aims to solve the problem that the prior electronic nose is inaccurate in measurement result due to the mixing of air in an air inlet pipe when used for a long time.

The technical scheme of the invention is as follows:

an electronic nose comprising: the sensor array is positioned in the airflow channel; wherein, the electron nose still includes: and the air flow control part is used for blowing out the gas to be detected in the air flow channel.

In a further preferred scheme, the airflow control part has two states of suction and discharge, gas to be detected is introduced into the airflow channel during suction, and the gas to be detected in the airflow channel is blown out during discharge.

In a further preferred embodiment, the wall of the air flow channel is undulated.

In a further preferred version, the sensor array is located at the top end wall of the airflow channel.

In a further preferred scheme, the air flow control part is a fan or an air pump, and the air volume of the air flow control part is between 10CFM and 50 CFM.

In a further preferred embodiment, the air flow control member has an air volume of 35 CFM.

An odor recognition method, which is implemented based on the electronic nose as described above, includes:

training sample learning is carried out by utilizing a chaos optimization algorithm;

gas to be detected enters the gas flow channel;

the sensor array senses the gas to be detected and outputs a signal according to a sensing result;

the pattern recognition application program recognizes the gas composition from the signals output by the sensor array;

the air flow control part blows out the gas to be detected in the air flow channel;

the sensor array continues to sense new sensing gas entering the gas flow path until the task is completed.

In a further preferred embodiment, the step of learning the training samples by using the chaotic optimization algorithm specifically includes:

initializing a network weight by using a chaotic algorithm;

reading a set of training samples;

calculating output values of each layer of the network;

calculating errors between the output values;

and judging whether the calculated error is smaller than a preset threshold value, if so, continuing to read the next group of training samples until the reading of the training samples is finished.

In a further preferred embodiment, the step of determining whether the calculated error is smaller than a preset threshold, and if so, continuing to read the next set of training samples until the reading of the training samples is finished further includes: if not, calculating local gradients of each layer of the network, adding a chaotic nonlinear operator, and updating the weight of the network.

A storage medium having a computer program stored thereon, wherein the computer program, when being executed by a processor, realizes the steps of the scent recognition method as described above.

Compared with the prior art, the electronic nose provided by the invention comprises: the gas detection device comprises a gas flow channel, a sensor array and a gas flow control piece, wherein the sensor array is positioned in the gas flow channel, and the gas flow control piece is used for blowing out gas to be detected in the gas flow channel. Therefore, the electronic nose provided by the invention can purify the air flow channel, prevents the sensor from fatigue and prevents residual gas in the air flow channel from influencing the subsequent gas detection result, and solves the problem that the measurement result is inaccurate due to the mixing of gas in the air inlet pipe when the electronic nose is used for a long time in the prior art.

Drawings

Fig. 1 is a schematic structural diagram of an electronic nose in the prior art.

Fig. 2 is a top view of a prior art top cover for an electronic nose.

Fig. 3 is an enlarged view of a prior art upper cover for an electronic nose.

Fig. 4 is a schematic structural diagram of the electronic nose of the present invention.

Fig. 5 is a schematic diagram of the scent recognition method of the present invention.

Detailed Description

The invention provides an electronic nose, a smell identification method and a storage medium, and in order to make the purpose, technical scheme and effect of the invention clearer and clearer, the invention is further described in detail below by referring to the attached drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

As shown in fig. 4, the present invention provides an electronic nose, including: the gas flow control device comprises a gas flow channel 100, a sensor array 200 and a gas flow control member 300, wherein the gas flow channel 100 simulates a nasal cavity of a human body, namely a gas flow channel, and the sensor array 200 senses the position of gas to be detected; the sensor array 200 (preferably, the sensor is an odor recognition sensor) is configured to sense a gas to be detected, after the gas is detected, the resistance of the corresponding sensor changes, the change is converted into a voltage change by the measurement circuit, the voltage change is converted into a digital signal by the ADC, and the digital signal is output, and the pattern recognition software in the computing device (for example, a computer) processes the digital signal to display a recognition result (please refer to fig. 5 for a specific test pattern, and the test patterns of tests 1 to N in fig. 5 indicate test patterns).

The airflow control member 300 is used for blowing out the gas to be detected in the airflow channel 100, and is preferably arranged at the tail end of the airflow channel 100 to simulate the lung of a human body; the timing of activating the gas flow control member 300 is not specifically limited in this application, but it is understood that when the gas to be detected in different groups is identified, the gas flow channel 100 can be cleaned once after the detection of one group of gas is completed, so as to prevent the group of gas from mixing with the next group of gas, and reduce the detection accuracy.

Based on this, the electronic nose provided by the invention can purify the air flow channel 100, prevent the sensor fatigue and the influence of residual gas in the air flow channel 100 on the subsequent gas detection result, and solve the problem that the measurement result is inaccurate due to the mixing of gas in the air inlet pipe when the electronic nose is used for a long time in the prior art.

As a preferred embodiment of the present invention, the air flow control member 300 has two states of inhaling and exhausting, wherein the gas to be detected is introduced into the air flow channel 100 during inhaling, and the gas to be detected in the air flow channel 100 is blown out during exhausting, so as to simulate the breathing process of a human body. Taking the airflow control member 300 as a fan for illustration, when the fan is rotated forward, the speed of the gas to be detected entering the airflow channel 100 is increased; when the fan is reversed, the air in the airflow channel 100 will be blown out.

According to another aspect of the present invention, the walls of the airflow channel 100 are wavy (at least the bottom wall is wavy), simulating the structure of the nasal cavity of a human body; in addition, the sensor array 200 can be arranged on the top wall part to increase the contact degree of the gas to be detected and the sensor, as shown in fig. 4, the gas flow flows along the waves, and the gas flowing through the sensor is increased when the sensor is arranged obliquely above the wave crest.

According to another aspect of the present invention, the airflow control member 300 is a fan or an air pump, and the airflow rate of the airflow control member 300 is between 10CFM and 50CFM, preferably 35CFM (CFM is an abbreviation of cubic fe per minute for cubic feet per minute; 1CFM 28.3185L/MIN), similar to the flow rate of a human nose. It should be noted that the flow rate can be increased or decreased at any time according to the requirement, and the breathing process of the nose can be better simulated by matching with the forward rotation and the reverse rotation of the fan (or structural members with similar functions such as an air pump and the like).

In addition, the present invention also provides an odor recognition method, which is implemented based on the electronic nose as described above (please refer to fig. 4), including:

training sample learning is carried out by utilizing a chaos optimization algorithm;

the gas to be detected enters the gas flow channel 100;

the sensor array 200 senses the gas to be detected and outputs a signal according to a sensing result;

the pattern recognition application identifies the gas composition from the signals output by the sensor array 200;

the gas flow control member 300 blows out the gas to be detected in the gas flow channel 100;

sensor array 200 continues to sense new sensing gas entering gas flow channel 100 until the task is completed.

In a further preferred embodiment, the step of learning the training samples by using the chaotic optimization algorithm specifically includes:

initializing a network weight by using a chaotic algorithm;

reading a set of training samples;

calculating output values of each layer of the network;

calculating errors between the output values;

and judging whether the calculated error is smaller than a preset threshold value, if so, continuing to read the next group of training samples until the reading of the training samples is finished.

In a further preferred embodiment, the step of determining whether the calculated error is smaller than a preset threshold, and if so, continuing to read the next set of training samples until the reading of the training samples is finished further includes: if not, calculating local gradients of each layer of the network, adding a chaotic nonlinear operator, and updating the weight of the network.

In recent years, the rapid development of artificial neural networks brings a new opportunity for pattern recognition of the electronic nose, and as the neural networks can realize nonlinear mapping, a neural network method is introduced into the electronic nose to establish an electronic nose neural network pattern recognition system. However, neural network learning algorithms such as Hebb learning algorithm, BP algorithm and the like have the disadvantages of slow convergence rate and easy trapping in local minimum, and the learning rate, accuracy and network popularization performance of the BP algorithm are poor, so that the requirements of practical application cannot be met.

Chaos exists in olfactory perception, and the theory of chaos can be used to understand some irregular activities in the brain. Because the chaotic neural network has rich neural networks fused at a point far away from a balance point, a system with learning ability can be formed, and therefore, different from a conventional neural network only having gradient descent characteristics, the chaotic neural network has the dynamic characteristics far away from the balance point and has various attractors. Due to the accumulation of the self-inhibition effect of the chaotic neural network, the state of the chaotic neural network only moves to a certain fractal structure on a phase space, and the characteristic is an effective mechanism for avoiding local extremum.

The method introduces a chaos optimization method into a neural network mode recognition system of an electronic nose, breaks through the mode of a traditional network learning algorithm, directly utilizes the abundant space-time dynamic characteristics of chaos variables in a network weight domain space, utilizes the attractor transfer caused by dynamic evolution, searches randomly in the domain space, controls the chaos dynamics to completely disappear by using a selection method, once the chaos dynamics disappears, the method shifts to a gradient descent optimization process, further optimizes the weight obtained in the first stage in a small range according to a gradient descent mechanism, and forms a system with strong learning capability.

In order to overcome the defects that the BP algorithm is low in convergence speed and easy to fall into local minimum, a nonlinear feedback term is introduced into a dynamics equation of the neural network connection weight, so that the network has chaotic dynamics behaviors in a weight space. The neural network applying the chaotic algorithm integrates the advantages of randomness and a deterministic algorithm, and has richer and more flexible dynamic characteristics, stronger capability of searching a global optimal solution and higher searching efficiency compared with a common neural network.

The chaotic optimization algorithm is adopted to learn the neural network, the training iteration times are far less than those of the standard BP algorithm and the momentum BP algorithm, and therefore the effectiveness of the chaotic optimization-based neural network BP algorithm provided by the method is verified in the aspect of enabling the neural network to be fast converged. Learning through a large number of training samples shows that: the algorithm is simple and easy to implement, small in calculated amount, good in stability and high in convergence rate, and solves the problem that the traditional neural network learning algorithm is difficult to overcome.

The invention also provides a storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the scent recognition method as described above.

It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by hardware instructions of a computer program, which can be stored in a non-volatile computer-readable storage medium, and when executed, can include the processes of the embodiments of the methods described above. Any reference to memory, storage, databases, or other media used in embodiments provided herein may include non-volatile and/or volatile memory. Non-volatile memory can include read-only memory (ROM), Programmable ROM (PROM), Electrically Programmable ROM (EPROM), Electrically Erasable Programmable ROM (EEPROM), or flash memory. Volatile memory can include Random Access Memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms such as Static RAM (SRAM), Dynamic RAM (DRAM), Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDRSDRAM), Enhanced SDRAM (ESDRAM), synchronous Link (SyNchlinNk) DRAM (SLDRAM), Rambus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

It is to be understood that the invention is not limited to the examples described above, but that modifications and variations may be effected thereto by those of ordinary skill in the art in light of the foregoing description, and that all such modifications and variations are intended to be within the scope of the invention as defined by the appended claims.