Electronic nose with gas exchange system and robot equipped with it

Abstract

Electronic nose with gas exchange system, comprising: an air inlet unit (21) comprising a filter (212), a first air inlet channel (210) and a second air inlet channel (211), wherein the filter (212) is fluidically connected to the first air inlet channel (210), the first air inlet channel (210) is provided for supplying an external gas via the filter (212) and the second air inlet channel (211) is used to supply an unfiltered gas to be detected; a detection unit (22) comprising a chamber (220) and a detection module, wherein the chamber (220) is fluidically connected to the downstream region of the first air inlet duct (210) and the second air inlet duct (211), and wherein the detection module comprises a gas sensor element (221) and one or more environmental sensor elements (222), wherein the gas sensor element (221) is designed to detect the gas in the chamber (220) and to generate a detection signal in response to the gas in the chamber (220), while the environmental sensor element (222) serves to detect one or more environmental parameters in the chamber (220), wherein the first air inlet duct (210) remains open until the detection signal and the environmental parameters reach an equilibrium state and is closed after this equilibrium state is reached, whereupon the second air inlet duct (211) is opened; a suction unit (23) connected to the chamber (220); and a processing unit (24) connected to the detection module and receiving the detection signal generated by the detection module, wherein the processing unit (24) determines evaluation information relating to the external gas based on the detection signal generated by the external gas entering the chamber (220) from the second air inlet channel (211).

Description

The present invention relates to an electronic nose, and more particularly to an electronic nose having a gas exchange system suitable for integration into a robot.In modern society, robots are used in a variety of applications including industrial automation, home care, environmental monitoring, disaster control, safety inspection, and gas analysis. In order to detect the environment and take corresponding measures, robots are usually equipped with a plurality of sensors. An important sensor in this context is the electronic nose, a gas sensor system capable of detecting and quantitatively analyzing simple and complex odors. By using specific gas sensors, an electronic nose can monitor the ambient air, compare it with stored reference data and carry out a comprehensive analysis. This technology enables, among other things, the detection of toxic or hazardous gases for hazard warning, the monitoring of the air quality, the early detection of fires or gas leaks, the use in medical diagnostics and the analysis of foods and other substances.Conventional electronic nose systems, however, have various technical limitations. For example, continuous acquisition of gases to be analyzed in a mobile robot may result in gas concentrations of the previous location interfering with measurements at the current location, which may result in measurement inaccuracies or misinterpretations. Moreover, some existing electronic nose systems rely on a separate air cleaner unit, resulting in increased system cost and bulky design. This significantly limits the suitability for mobile robot systems and limits their possible uses.The object of the invention is to provide an electronic nose with a gas exchange system which avoids the above disadvantages by simple measures.This object is achieved according to the invention by an electronic nose with a gas exchange system having the features specified in claim 1. Further advantageous developments of the invention emerge from the features of the dependent claims.According to the invention, an electronic nose with a gas exchange system is provided, comprising an air inlet unit, a detection unit, an extraction unit and a processing unit. The air inlet unit includes a filter, a first air inlet duct and a second air inlet duct, the filter being fluidly connected to the first air inlet duct. The detection unit comprises a chamber and a detection module, wherein the chamber is fluidically connected to the first air inlet duct and the second air inlet duct. The detection module comprises a gas sensor element and one or more environmental sensor elements. The gas sensor element is for detecting the gas in the chamber and generates a detection signal in response to the gas in the chamber. The environmental sensor elements sense one or more environmental parameters within the chamber. The suction unit is connected to the chamber, and the processing unit is connected to the detection module and receives the detection signal generated by it. The electronic nose is configured to perform the steps of: first, an external gas is introduced into the chamber through the filter via the first air inlet duct until the detection signal generated by the detection unit and the environmental parameters detected by the environmental sensor elements reach an equilibrium state, whereupon the first air inlet duct is closed. Subsequently, the external gas is introduced into the chamber via the second air inlet duct. Based on the detection signal generated by the gas supplied via the second air intake passage, evaluation information regarding the external gas is determined. Furthermore, a robot is provided which comprises a robot structure and an electronic nose according to the embodiment described above. The electronic nose is attached to the robot structure and fluidly connected to the external environment.The invention and its embodiments are explained in more detail below with reference to the drawings. The drawing shows: FIG. 1 is a perspective view of a robot according to an embodiment of the present invention; FIG. 2A is a schematic diagram of a robot according to an embodiment of the present invention; FIG. 2B is a schematic diagram of a robot according to another embodiment of the present invention; FIG. 3 is a schematic diagram of a robot according to still another embodiment of the present invention; FIG. 4 is a schematic flow diagram of the process of operation of the electronic nose of the present invention with a gas exchange system; and FIG. 5 is a schematic illustration of the change in resistance over time during operation of the electronic nose.It is to be understood that the terms used below are used to describe specific examples and are not to be interpreted as limiting. Unless the context clearly indicates otherwise or the number of elements is explicitly limited, the singular form used in this document includes, for example, "a", "the" also the plural. It is further understood that the terms "comprise" and / or "include" indicate the presence of the stated features, elements and / or components, but do not preclude the addition or presence of one or more further features, elements, components and / or groups. Indefinite and specific articles are to be understood both in the singular and in the plural, unless the context clearly indicates otherwise.The present invention discloses an electronic nose having a gas exchange system. In one embodiment, this electronic nose is provided for integration into a robot. The robot may be an autonomous mobile robot, a keyless transport vehicle, an articulated robot, a humanoid robot, a collaborative robot, or a hybrid robot. It can likewise be a mechanical or biomimetic robot. Specific, but non-limiting examples are patrol robots, exploratory robots or household assistance robots. Although the examples are given, the present invention is not limited to these, and the term "robot" should be broadly construed here.FIG. 1 shows a robot 10 as an embodiment of the present invention. The robot 10 is a wheel-driven robot equipped with an electronic nose 20. The robot 10 has a robot structure 11, and the electronic nose 20 is attached to this structure 11. At least a portion of the electronic nose 20 protrudes from the housing of the robot 10 so that it can contact the ambient air and perform real-time gas analysis. The electronic nose 20 allows the robot 10 to continuously record gas concentrations in its environment and to initiate corresponding reactions on the basis of the measurement results. The ambient air refers to the gas mixture that is located in the direct environment of the robot 10 or the electronic nose 20.For example, the robot 10 may be used in industrial or residential environments where it may detect potentially harmful gases such as carbon monoxide, carbon dioxide, ozone, sulfur dioxide, nitrogen dioxide, volatile organic compounds, or formaldehyde. The electronic nose 20 allows the robot 10, rather than human workers, to detect the presence of such gases and compare their concentrations to safety limits. If these values are exceeded, the robot 10 can emit warning signals or activate ventilation systems in order to improve the air exchange with the environment. Similarly, the robot 10 can be used in extreme or unexplored environments such as deep sea, cavities or space to perform real-time analysis of the gases present there and provide information about their composition by means of the electronic nose 20.Referring to FIG. 2A, the electronic nose 20 according to an embodiment includes an air inlet unit 21, a detection unit 22, an exhaust unit 23, and a processing unit 24.The air inlet of the air inlet unit 21 is fluidly communicated with the outside environment. In one example, the air inlet is disposed on the housing of the robot 10 to allow direct intake of ambient air into the electronic nose 20. The detection unit 22 comprises a chamber 220 and a detection module. The detection module may be disposed within the chamber 220, but is not limited thereto, and may be installed at other positions that enable detection within the chamber 220. The chamber 220 has at least one or more inlet openings and an exhaust air opening. The upper flow path of the chamber 220 is fluidly connected to the air intake unit 21 via the inlet port thereof to receive the ambient air introduced through the inlet of the air intake unit 21. The lower flow path of the chamber 220 is fluidically connected to the suction unit 23 via the exhaust air opening. Due to the vacuum effect generated by the suction unit 23, the ambient air is conducted from the air inlet unit 21 into the chamber 220 and subsequently discharged through the suction unit 23.The processing unit 24 is connected to the air inlet unit 21 and the suction unit 23 and controls these respectively with regard to the flow channel and the flow speed. The air intake unit 21 is configured to be capable of selectively introducing unfiltered ambient air [air to be detected] or filtered ambient air [filtered air]. The processing unit 24 controls which of these air types is allowed to enter the chamber 220 via the inlet opening of the air inlet unit 21, controls the switching on and off of the suction unit 23 and the intensity of the vacuum generated in order to control or adapt the flow speed of the ambient air flowing into or passed through the chamber 220.In an embodiment, the air inlet unit 21 may include two air lines, for example, a first air inlet duct 210, a second air inlet duct 211, and a filter 212. The filter 212 is disposed within the first air intake passage 210, but may alternatively be located in front of or behind the first air intake passage 210. The first air inlet duct 210 serves to supply filtered ambient air into the chamber 220, while the second air inlet duct 211 directs the unfiltered ambient air into the chamber 220. In one example, the first air inlet duct 210 and the second air inlet duct 211 are each connected to a valve body 213, 214 connected to and controlled by the processing unit 24. In another example, the electronic nose 20 may include a three-way valve 215, as shown in FIG. 3. The three-way valve 215 is connected to and controlled by the processing unit 24. It controls communication between the first air inlet duct 210 and the chamber 220 or the second air inlet duct 211 and the chamber 220. In one example, the filter 212 may be an activated carbon filter that is used to adsorb or filter volatile organic compounds [VOC], but the present invention is not limited thereto.Referring back to FIG. 2A, the detection module includes a gas sensor element 221 and one or more environmental sensor elements 222. The gas sensor element 221 and the environmental sensor element 222 may be disposed within the chamber 220 or partially project into the chamber 220, as illustrated in FIG. 2B. However, this is not limited thereto, since the detection module may be installed at other positions within the chamber 220 as long as it can contact and detect the gas in the chamber 220. In one embodiment, gas sensor element 221 is a device that can generate electrical signals or determine their characteristics in response to particular gases. Examples of these are chemoresistive or electrochemical gas sensor arrays and semiconductor gas sensors. However, the present invention is not limited thereto. The gas sensor element 221 may also have other designs or structures, such as optical gas sensors or electrochemical gas sensors.The gas sensor element 221 serves to detect the gases contained in the chamber 220 or their changes. This may include identification of the types of gases present in chamber 220, the presence of one or more specific constituents, the concentration or amount of these constituents [or their exceeding of a certain value], the agreement of the gas mixture with a specific composition, or the change of certain constituents, compositions or concentrations. Examples of specific components are oxygen, carbon monoxide, hydrogen sulfide, ammonia, chlorine, ozone, sulfur dioxide, nitrogen dioxide, natural gas, liquefied gas, methane and propane. Examples of specific compositions are toxic gases or combustible gases.The gas sensor element 221 detects the gas present in the chamber 220 and generates a detection signal that varies depending on the gases present in the chamber 220. If a chemoresistive gas sensor array is used, the detection signal is based on the electrical resistance value caused by the interaction between the gas and the sensor array [e.g. a change from 0 to a specific value] or on a change in the resistance value [e.g. a change from a first initial value to a second value]. The detection signal can be used to determine evaluation information relating to the external gas. This evaluation information can comprise, for example, the presence of one or more specific constituents in the external gas, the concentration or amount of these constituents [or their reaching of a specific threshold value], the correspondence of the external gas with a defined composition or a change in specific constituents, compositions or concentrations in the external gas.The environmental sensor element 222 serves to sense one or more environmental parameters within the chamber 220. These environmental parameters may include temperature, humidity, pressure, air pressure, or any combination thereof. Referring to FIG. 3, depending on the environmental parameters to be sensed, the environmental sensor element 222 may include a temperature sensor element 222a, a humidity sensor element 222b, a pressure-air pressure sensor element 222c, or any combination thereof. The temperature sensor element 222 a, the humidity sensor element 222 band the pressure sensor element 222 care each configured to measure the temperature, the humidity and the pressure inside the chamber 220.In the exemplary embodiment shown in FIG. 3, the electronic nose 20 is integrated into the robot 10 as a system of modular construction. The processing unit 24 may be further connected to a control unit 30 of the robot 10. The control unit 30 may include a processor 31, a database 32, and a communication interface 33. It serves to control the processing unit 24, to receive signals from the processing unit 24, or as a connection path between the electronic nose 20 and other external components. In one embodiment, processor 31 may process the detection signal generated by gas sensor element 221 as well as the environmental parameters detected by environmental sensor element 222. For example, the processor 31 may match the detection signal with the data stored in the database 32 and generate an analysis result related to the external gas. In another embodiment, the processor 31 may perform artificial intelligence AI-based calculation such that the robot 10 may perform the analysis of the detection signal and / or environmental parameters locally using generative AI methods. In other exemplary embodiments, the control unit 30 can be connected via the transmission interface 33 to an external device 40, for example to a server or an external database. The transmission interface 33 may include a wired or wireless communication interface according to any one of the following protocols: WiFi, BLE, Bluetooth, Z-Wave, USB, or Zigbee. It should be understood that in other embodiments, the control unit 30 may also be integrated with the electronic nose 20 into a modular unit and is not limited to the configuration described above.Referring to Fig. 4, the operation of the electronic nose 20 is illustrated, with additional reference to Fig. 5. The process of detecting the electronic nose 20 essentially comprises two phases: a preparation phase P1 and a detection phase P2. In the preparation phase P 1, the processing unit 24 activates the suction unit 23 and controls the air inlet unit 21 so that filtered ambient air [filtered gas] is guided into the chamber 220 [step 80]. The filtered gas does not represent the gas to be detected, but functions as a background gas or cleaning medium for the chamber 220. This ensures that the chamber 220 is freed of residual gases and is in a stable state before the actual detection begins. In certain operating conditions, the preparation phase P 1 can also be considered a pre-cleaning phase.The processing unit 24 receives the detection signal generated by the gas sensor element 221 and the environmental parameters detected by the environmental sensor element 222. Based on the values of the detection signal and the environmental parameters, the processing unit 24 monitors and evaluates whether the equilibrium state has been reached in step 51. The equilibrium state denotes the state in which the detection signal and one or more of the environmental parameters detected in the chamber 220 reach an equilibrium value. These environmental parameters may include temperature, humidity, and / or pressure. It is understood that the equilibrium state can already be considered to be reached when an individual environmental parameter [e.g. only the temperature] or a plurality of environmental parameters are stabilized. The more environmental parameters reach a stable equilibrium, the more conducive this is for precise detection. Reaching the equilibrium value means that the detection signal and the environmental parameters in the chamber 220 remain substantially constant. In an embodiment, this substantial constancy may be interpreted as a temporal stability within a defined range of variation, for example a variation within ±10%, ±5% or ±1%. The processing unit 24 may evaluate whether the equilibrium state has been reached. For example, this is considered to be achieved if the electrical resistance value and the environmental parameters temperature, air humidity, pressure or any combination thereof have a substantially constant stability over a predefined period of time and this stability continues for a defined minimum duration. In other words, the equilibrium state describes a period of time within the preparation phase P 1, during which the detection signal and the environmental parameters remain substantially constant over a continuous duration. In one embodiment, the exhaust unit 23 is controlled such that the flow rate of the filtered gas into the chamber 220 remains substantially constant. A stable gas flow within chamber 220 helps to achieve equilibrium in a shorter time.As illustrated in FIG. 5, in the preparation phase P 1, the electric resistance value of the detection signal generated by the gas sensor element 221 gradually increases with time starting from the initial resistance value R 0 and reaches, after a certain time, a first resistance value R 1 at which it remains stable [time T 1]. At this moment, the equilibrium state is reached. The period from the beginning of the preparation phase to T 1 is defined as the first period.Once the equilibrium state is reached, the detection phase P2 begins [step 52]. In this exemplary embodiment, when the transition from the preparation phase P 1 to the detection phase P 2, the processing unit 24 will still keep the suction unit 23 activated and at the same time control the air inlet unit 21 such that unfiltered ambient air [gas to be detected] reaches the chamber 220. The gas flowing in the chamber 220 in this phase consists exclusively of unfiltered outside air to be detected. In this example, the air intake unit 21 remains activated continuously. During the preparation phase P 1, the first air inlet duct 210 is open, while the second air inlet duct 211 remains closed. At the beginning of the detection phase P 2, the second air inlet duct 211 is opened, while the first air inlet duct 210 is closed.Since a gas different from that in the preparation phase P 1 flows in the chamber 220, the detection signal resistance value generated by the gas sensor element 221 changes as illustrated in FIG. 5. The resistance value changes from the first resistance value R 1 to a second resistance value R 2 and reaches a stable state at T 2. The period from T 1 to T 2 is defined as a second period. The second resistance R2 is responsive to one or more characteristics of the unfiltered external gas. The evaluation information on this external gas is determined from the second resistance value R 2. The processing unit 24 receives the detection signal generated by the gas sensor element 221 and the environmental parameters detected by the environmental sensor element 222 [step 83], and acquires the evaluation information based on the detection signal. In one embodiment, the detection is at room temperature, i.e., the gas in chamber 220 is not heated. However, the present invention is not limited thereto. In certain embodiments, the detection may also be performed with heated gas in the chamber 220. It should be understood that the external gas evaluation information is not based on the detection signal of the first period, but is based exclusively on the detection signal acquired during the detection phase P 2.In one embodiment, the equilibrium state refers specifically to the state of the chamber 220 while the gas is in motion inside, i.e., as an air stream, not a static gas. In a further exemplary embodiment, the suction unit 23 continues to remain active during the transition from the preparation phase P 1 to the detection phase P 2. As a result, the external gas is first introduced into the chamber 220 via the first air inlet duct 210 and then smoothly switched over to the supply via the second air inlet duct 211. The filtered external gas forms a first air flow within the chamber 220, while the unfiltered external gas forms a second air flow. The flow speeds of the first air flow during the preparation phase P 1 and of the second air flow during the detection phase P 2 are substantially identical. Since the suction unit 23 is not deactivated during the transition from the preparation phase P 1 to the detection phase P 2, the gas flow within the chamber 220 remains continuous, only with a change of the supplied gas. This results in the environmental parameters within the chamber 220 changing only slightly, so that the equilibrium state is hardly disturbed or impaired. As a result, it is not necessary to restore the equilibrium of the chamber 220, which increases the measurement accuracy and shortens the measurement time required. Under the operating conditions described, the equilibrium state can be interpreted as a dynamic equilibrium.Since the stability of the detection environment must be ensured during the introduction of the external gas and the subsequent detection in order to achieve precise measurement results, the equilibrium state is required to be reached. Therefore, prior to the delivery of the unfiltered gas to be detected, it is first ensured that the ambient conditions within the chamber 220 remain in dynamic equilibrium. This means that the environmental parameters remain substantially constant during the gas flow. Subsequently, the unfiltered gas to be detected is introduced by switching over the supply without interrupting the gas flow. As a result, the flow velocity remains substantially constant, so that the gas pressure within the chamber 220 remains at a comparable level in both phases.In certain aspects of the present invention, the equilibrium state need not necessarily be in dynamic equilibrium, but alternatively may be achieved in static equilibrium. The difference in operating mode is that after completion of the preparation phase P 1, the suction unit 23 is first deactivated. As a result, the detection signal and the environmental parameters within the chamber 220 may stabilize in a state without gas flow before the detection phase P 2 is initiated. According to another embodiment, the electronic nose 20 may be selectively operated in either dynamic equilibrium or static equilibrium modes.In summary, the electronic nose of the invention uses a two air inlet duct approach to perform the gas exchange function. Although gas is supplied continuously, it is not continuously the gas to be detected, but filtered gas is initially introduced. This eliminates the problem of signal noise which occurs in conventional electronic noses of robots. Moreover, in the dynamic equilibrium mode of the present new development, the introduction of gas is more efficient than in conventional electronic noses which perform a precleaning with clean gas before the detection and switch off the pump in the transition phase between precleaning and detection. In contrast, in the present development, the suction unit remains continuously in operation, whereby the gas detection can be carried out more efficiently. Since gas is continuously fed into the chamber during the entire detection preparation and the detection phase, no sudden changes in the measurement signals occur due to abrupt environmental changes, as would be the case if no gas were introduced into the chamber before the detection and were only fed at the detection time. Instead, a stable change of the detection signal takes place, whereby a higher measurement accuracy is ensured. In addition, the rapid pre-cleaning allows background gases in different environments not to interfere with one another, which is advantageous in particular in the case of mobile robots which carry out measurements in different rooms.In summary, an electronic nose 20 with gas exchange system is disclosed, comprising an air inlet unit 21, a detection unit 22, an extraction unit 23 and a processing unit 24. the air inlet unit 21 comprises a first air inlet duct 210 and a second air inlet duct 211. The detection unit 22 comprises a chamber 220 and a detection module, wherein the detection module has a gas sensor element 221 and one or more environmental sensor elements 222. The suction unit 23 is connected to the chamber 220 and the processing unit 24 is connected to the detection module. The electronic nose 20 is configured to direct an external gas into the chamber 220 via the first air inlet duct 210 through a filter 212 until the detection signal generated by the detection unit 22 and the environmental parameters detected by the environmental sensor element 222 reach an equilibrium state. Subsequently, the external gas is introduced into the chamber 220 via the second air inlet duct 211, wherein evaluation information regarding the external gas is determined on the basis of the detection signal.

Claims

An electronic nose with gas exchange system, comprising: an air inlet unit (21) having a filter (212), a first air inlet duct (210) and a second air inlet duct (211), wherein the filter (212) is fluidly connected to the first air inlet duct (210), the first air inlet duct (210) is provided for supplying an external gas via the filter (212), and the second air inlet duct (211) is for supplying an unfiltered gas to be detected; a detection unit (22) comprising a chamber (220) and a detection module, wherein the chamber (220) is fluidly connected to the downstream portion of the first air inlet duct (210) and the second air inlet duct (211), and wherein the detection module comprises a gas sensor element (221) and one or more environmental sensor elements (222), wherein the gas sensor element (221) is configured to detect the gas located in the chamber (220) and to generate a detection signal in response to the gas in the chamber (220), while the environmental sensor element (222) is used to detect one or more environmental parameters in the chamber (220), wherein the first air inlet duct (210) remains open until the detection signal and the environmental parameters reach an equilibrium state and is closed after reaching this equilibrium state, whereupon the second air inlet duct (211) is opened; an extraction unit (23) connected to the chamber (220); and a processing unit (24) connected to the detection module and receiving the detection signal generated by the detection module, wherein the processing unit (24) acquires evaluation information regarding the external gas based on the detection signal generated by the external gas entering the chamber (220) from the second air inlet duct (211).The electronic nose according to claim 1, characterized in that the processing unit (24) is connected to a control unit (30), wherein the control unit (30) comprises a processor (31) configured to perform artificial intelligence (AI)-based calculations and a database (32), wherein the processor (31) is configured to perform an AI calculation and generate an analysis result based on the database (32) and the detection signal.The electronic nose according to any one of the preceding claims, characterized in that the external gas is continuously supplied via the first air inlet duct (210) through the filter (212) into the chamber (220) for a first period of time, wherein the equilibrium state is defined as a state in which the detection signal and the environmental parameters remain substantially constant within a range of the first period of time, respectively, and wherein the external gas is supplied via the second air inlet duct (211) into the chamber (220) for a second period of time.Electronic nose according to one of the preceding claims, characterized in that, in the equilibrium state, the detection signal and the temperature, the air humidity and the air pressure within the chamber (220) each remain substantially constant within the defined range.The electronic nose according to any one of the preceding claims, characterized in that the electronic nose (20) is configured such that the external gas is first supplied via the first air inlet duct (210) and then smoothly switched to the supply via the second air inlet duct (211).Electronic nose according to any of the preceding claims, characterized in that the environmental parameters are selected from a group consisting of the temperature, the humidity and the air pressure inside the chamber (220), combinations of these parameters also being included.Electronic nose according to any of the preceding claims, characterized in that the gas sensor element (221) is a chemoresistive gas sensor and the detection signal represents a resistance value.Electronic nose according to any of the preceding claims, characterized in that the environmental sensor element (222) is selected from a group consisting of a temperature sensor element (222a), a humidity sensor element (222b) and a pressure sensor element (222c), combinations of these elements also being included.Electronic nose according to any of the preceding claims, characterized in that after equilibrium has been reached and during the supply of the external gas via the second air inlet duct (211), the environmental parameters remain substantially constant.A robot comprising: a robot structure (11); and an electronic nose (20) according to any one of claims 1 to 9, which is disposed on the robot structure (11) and fluidly connected to the external environment.

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