Electronic nose for fast detection and robot equipped with it

Abstract

Electronic nose for a robot, comprising: an air inlet unit (10) configured to introduce an ambient gas; a detection unit (20) comprising a chamber (21), a circulation line (22) and a detection module, wherein an inlet (210) of the chamber (21) is connected to the air inlet unit (10) and together defines an air inlet channel (12), wherein the circulation line (22) is connected to an outlet (211) of the chamber (21) and the inlet (210) and forms a circulation channel (23), and wherein the detection module comprises a gas detection element (24) and one or more environmental detection elements (25), and wherein the gas detection element (24) serves to detect the gas present in the chamber (21) and to generate a detection signal in response to the gas present in the chamber (21), and wherein the environmental detection element (25) serves to detect one or more environmental parameters within the chamber (21), and wherein the Circulation channel (23) is configured sothat it transports a circulating gas flow for cleaning the chamber (21), and the air inlet channel (12) is configured to convey the ambient gas to be detected; , a cleaning unit (30) arranged within the chamber (21) and through which the circulating gas flow is passed, the cleaning unit (30) comprising a carrier (31), a photocatalyst arranged on the carrier (31) and a luminous element (32) which emits light onto the photocatalyst located on the carrier (31); an exhaust unit (40) connected to the circulation line (22) for directing the gas within the chamber (21) from the outlet (211) back to the inlet (210); and a control system (50) connected to the detection module and receiving the detection signal generated by the detection module, wherein the control system (50) determines assessment information relating to the ambient gas based on the detection signal generated by the ambient gas introduced into the chamber (21) via the air inlet channel (12).

Description

The present invention relates to an electronic nose, particularly an electronic nose, which enables rapid detection and is suitable for integration into a robot.Robots are widely used in modern society, including factory automation, home care, environmental monitoring, disaster control, safety control and gas detection. Robots are usually equipped with various sensor devices in order to detect the environment and take appropriate measures. One of these sensing devices is the so-called electronic nose, a sensor system capable of identifying and quantitatively analyzing both simple and complex odors. In this case, electronic noses use gas sensors for detecting ambient gases in order to compare these with reference data and to perform a corresponding evaluation. This allows a wide variety of functions to be implemented, such as the detection and warning of noxious gases, the monitoring of the air quality, the early detection of fire events or gas leaks, the use in medical diagnostics and health monitoring, and the use in food analysis.Some existing electronic nose systems, particularly non-optical gas sensors, require continuous calibration and repeated identification processes to maintain monitoring of the ambient gases. Regardless of whether or not the gas composition in the environment changes, these systems must always undergo time-consuming identification processes, resulting in a delayed response to environmental changes.Moreover, the permanent execution of identification processes leads to an increased energy consumption and a shortened service life of the electronic nose.In addition, the cleaning or purification of the internal chamber of conventional electronic nose systems generally requires the supply of clean air. Frequently, a filter element is used for this purpose at the air inlet. However, the choice of the suitable filter medium entails technical challenges: if activated carbon is used, for example, a regular need for maintenance and replacement arises. Alternatively, molecular sieves may be used, but which involve particular requirements for storage conditions, such as additional protection from moisture or vacuum sealing. Therefore, there remains a need for optimization with respect to the gas cleaning technologies used in electronic nose systems.It is an object of the invention to provide an electronic nose which enables rapid detection and is suitable for integration into a robot.This object is achieved according to the invention by an electronic nose having the features specified in claim 1 and by a robot having the features specified in claim 13. Further advantageous developments of the invention emerge from the features of the dependent claims.According to the invention, there is provided an electronic quick detection nose comprising an air inlet unit configured to introduce an ambient gas; a detection unit comprising a chamber, a circulation line and a detection module, wherein the inlet of the chamber is connected to the air inlet unit and together forms an air inlet duct, the circulation line is connected to an outlet and the inlet of the chamber and defines a circulation duct, wherein the detection module comprises a gas detection element and one or more environment detection elements, the gas detection element is for detecting the gas present in the chamber and generates a detection signal that responds to the gas present in the chamber, the environment detection element is for detecting one or more environment parameters within the chamber, the circulation duct is configured to transport a circulating gas flow for cleaning the chamber, and the air inlet duct is configured to convey the environment gas to be detected; a cleaning unit comprising a support disposed in the gas flow, a photocatalyst disposed on the support, and a light emitting element emitting light onto the photocatalyst; a suction unit connected to the circulation line for guiding the gas from the chamber from the outlet back to the inlet; and a control system connected to the detection module and receiving the detection signal generated by the detection module, wherein the control system determines judgment information regarding the ambient gas based on the detection signal generated by the ambient gas introduced into the chamber via the air inlet channel.According to the invention, there is further provided a robot including a robot structure and an electronic nose, the electronic nose being formed in the above-described configuration and being disposed on the robot structure and communicating with the 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 illustration of an electronic nose in accordance with an embodiment of the present invention; FIG. 2B is a schematic illustration of an electronic nose in accordance with another embodiment of the present invention; FIG. 2C is a schematic illustration of an electronic nose in accordance with another embodiment of the present invention; FIG. 3 is a schematic illustration of an electronic nose in accordance with another embodiment of the present invention; FIG. 4 is a schematic diagram showing the operation flow according to an embodiment of the present invention; FIG. 5 is a schematic diagram showing the change in resistance (ΔRs) of the detection signal in the monitoring mode according to an embodiment of the present invention; and FIG. 6 is a schematic diagram showing the resistance change (Rs) of the detection signal in the identification mode according to an embodiment of the present invention.It is to be understood that the terms used in this specification are intended to represent specific examples and are not to be interpreted as limiting. Unless the context expressly indicates otherwise or the number of components is intentionally determined, the singular used in this specification includes "a", "the", and "the". Furthermore, it is to be understood that the terms "comprises" and / or "includes" indicate the presence of the described features, components, and / or elements, but do not preclude that other features, components, elements, and / or groups thereof may be added or present. Indefinite and specific articles are to be understood accordingly both in the singular and in the plural, unless the context indicates otherwise.The present invention discloses an electronic nose suitable for integration into a robot in one embodiment. The robot may be an autonomous mobile robot, a Keyless Transport System AGV, an articulated robot, a humanoid robot, a collaborative robot, or a hybrid robot. It can likewise be a mechanical or biomimetic robot, specific, non-limiting examples being a patrol robot, an exploration robot or a home care robot. Although these examples have been given, the present invention is not limited thereto, and the term "robot" should be interpreted in the broadest sense. Moreover, the scope of the present invention also includes applications that are not limited to robots.FIG. 1 shows an embodiment of a robot 1 according to the present invention. The robot 1 is a wheel-driven robot and is equipped with an electronic nose 2. The robot 1 includes a robot body 1 aon which the electronic nose 2 is disposed. For the purpose of directly detecting ambient gases, at least a part of the electronic nose 2 is led out of the housing of the robot 1, so that a direct contact with the surrounding air is possible. The robot 1 can continuously monitor the changes in the ambient gas concentration by means of the electronic nose 2 and can take corresponding measures on the basis of the detected measurement values. The ambient gases refer here to the air composition of the space or the environment in which the robot 1 or the electronic nose 2 is located.For example, in factories or domestic environments, harmful gases such as carbon monoxide, carbon dioxide, ozone, sulfur dioxide, nitrogen dioxide, volatile organic compounds and formaldehyde may occur in excessive concentrations. Instead of manual measurements, the robot 1 can detect by the electronic nose 2 whether these pollutants are present in the environment and whether their concentration exceeds a safety-critical limit value. In such a case, the robot 1 can initiate corresponding measures, such as, for example, outputting warning signals or activating a ventilation system in order to improve the air exchange with the environment. In addition, the mobile robot 1 with the electronic nose 2 can also be used in unknown or extreme environments such as deep sea, cavities or outer space in order to carry out a real-time analysis of the gases present in the environment and to provide information about the composition of the atmosphere there.Referring to FIG. 2A, an embodiment of the present invention shows that the electronic nose 2 includes an air inlet unit 10, a detection unit 20, a cleaning unit 30, an exhaust unit 40, and a control system 50. The air inlet unit 10 has an air inlet port 11 communicating with the environment and defines an air inlet duct 12. The detection unit 20 has a chamber 21 and a detection module which contains a multiplicity of identical or different sensors. The detection module may be disposed within the chamber 21, but is not limited thereto; it may also be installed at another position from which it can detect the conditions within the chamber 21. The chamber 21 has an inlet 210 and an outlet 211. At its inlet side, the chamber 21 is fluidly connected to the air inlet unit 10 via the inlet 210 to receive the ambient air introduced from the air inlet unit 10. On its outlet side, the chamber 21 is connected fluidically via the outlet 211 to the suction unit 40. Due to the vacuum effect generated by the suction unit 40, the gas inside the chamber 21 can be discharged via the outlet 211. Alternatively, the ambient air can be conducted from the air inlet unit 10 into the chamber 21 and subsequently discharged through the suction unit 40. Moreover, between the inlet 210 and the outlet 211 of the chamber 21, a circulation line 22 is provided, which defines a circulation channel 23.The gas flow through the air inlet duct 12 of the air inlet unit 10 is controlled by a first fluid control device 13, while the gas flow through the circulation duct 23 of the circulation duct 22 is controlled by a second fluid control device 231. In addition, both the first fluid control device 13 and the second fluid control device 231 may be used for controlling the gas flow rate within the air inlet duct 12 and the circulation duct 23. In this embodiment, the circulation channel 23 is connected to the air inlet channel 12 and further coupled to the inlet 210. The first fluid control device 13 and the second fluid control device 231 are each designed as three-way-controlled fluid control devices, for example as three-way valves [or three-way valves]. The first fluid control device 13 has a first opening 131, a second opening 132, and a third opening 133 connected to the air inlet opening 11, the outlet side of the circulation pipe 22, and the inlet 210 of the chamber 21, respectively. The second fluid control device 231 has a first port 232, a second port 233, and a third port 234 connected to the outlet 211 of the chamber 21, the inlet side of the circulation pipe 22, and a gas outlet 14, respectively. Accordingly, it can be controlled in a targeted manner whether the gas flows in from the air inlet opening 11, enters the chamber 21 via the inlet 210 and is discharged through the gas outlet 14. This is done by opening the first opening 131 and the third opening 133 of the first fluid control device 13, while the second opening 132 remains closed. At the same time, the first opening 232 and the third opening 234 of the second fluid control device 231 are opened, while the second opening 233 thereof of the second fluid control device 231 remains closed. Alternatively, the gas may be returned from the outlet 211 of the chamber 21 through the circulation channel 23. In this case, the first opening 232 and the second opening 233 of the second fluid control device 231 are opened while the third opening 234 of the second fluid control device 231 remains closed. In parallel, the second opening 132 and the third opening 133 of the first fluid control device 13 are opened, while their first opening 131 of the first fluid control device 13 remains closed, so that the gas flows back into the chamber 21 via the inlet 210.The cleaning unit 30 has a carrier 31 and a light element 32, and the carrier 31 can be designed as a net-like structure or as another element with gas permeability, for example as a filter fabric. A photocatalyst is arranged on the carrier 31, wherein the luminous element 32 serves for irradiation of the photocatalyst located on the carrier 31. In one embodiment, the photocatalyst may be made of titanium dioxide [TiO 2], zinc oxide [ZnO], manganese oxide [MnO 2], iron oxide [Fe 2 O 3] or a combination of these materials. Alternatively, it can be a composite photocatalyst material comprising a combination of said materials with further components such as silver, graphene or carbon nanotubes. The light element 32 can emit ultraviolet light, in particular deep UV light [UVC]. In one embodiment, the carrier 31 is disposed within the chamber 21. The cleaning unit 30 can have both a filtering and a cleaning function. In this case, the carrier 31 alone can filter the gases flowing through, while the luminous element 32 in combination with the photocatalyst cleanses the gases flowing through. In some embodiments, the cleaning unit 30 can be present in multiple embodiments, wherein the supports 31 are arranged within the chamber 21 with a defined distance from one another. The photocatalyst on the plurality of supports 31 may be irradiated by a single light emitting element 32 or by respective associated light emitting elements 32. As illustrated in FIG. 2C, the carrier 31 may be formed in a multi-layered structure.In a further exemplary embodiment, activated carbon can also be arranged on the carrier 31 in addition to the photocatalyst. The activated carbon is also capable of purifying the gases flowing through because it has a high adsorption capacity. Due to the rapid adsorption property of the activated carbon, pollutants can be efficiently removed from the gas stream. At the same time, the irradiation of the photocatalyst causes the substances adsorbed on the activated carbon to be decomposed, thereby delaying saturation of the activated carbon. This can considerably shorten the cleaning time and improve the problem of frequent replacement of the activated carbon.The suction unit 40 is configured to generate a negative pressure in the chamber 21 and thereby allow the gases to be sucked off. The suction unit 40 is disposed in front of the second fluid control device 231. The chamber 21 has an inlet portion 21a and an outlet portion 21b. The inlet portion 21a is located near and connected to the inlet 210, while the outlet portion 21b is located near and coupled to the outlet 211. When the suction unit 40 is activated and a negative pressure is thereby generated in the chamber 21, the gas within the chamber 21 flows from the inlet region 21 ainto the outlet region 21 b. The carrier 31 is disposed along the flow path of the gas within the chamber 21. The light emitting element 32 may be placed inside the chamber 21 or disposed at a position that enables direct irradiation of the carrier 31.The detection module comprises a gas detection element 24 and one or more environment detection elements 25. The gas detection element 24 and the environment detection elements 25 can be arranged within the chamber 21 or can at least partially project into the chamber 21, as shown in FIGS. 2B and 2C. Moreover, the detection module is not limited to this arrangement, but may be installed at another position as long as it can contact the gas inside the chamber 21 and grasp its characteristics. In one exemplary embodiment, the gas detection element 24 is designed as a device which generates or changes electrical signals as a function of a gas reaction.Examples of these are chemoresistive [or electrochemical] gas sensor arrays and semiconductor-based gas sensors. However, the present invention is not limited thereto, as the gas detection element 24 may have other shapes or structures, such as optical gas sensors or electrochemical gas sensors.The gas detection element 24 serves for detecting the gases present in the chamber 21 or the changes thereof. This may comprise identification of the gas types contained in the chamber 21, the presence of one or more specific constituents, the concentration or amount of these constituents [or reaching a certain threshold value], the correspondence of the gas composition with a predefined composition or changes of specific constituents, compositions or concentrations in the chamber 21. Specific ingredients may include, for example, oxygen, carbon monoxide, hydrogen sulfide, ammonia, chlorine gas, ozone, sulfur dioxide, nitrogen dioxide, natural gas, liquefied gas, methane and propane. The specific composition may refer to groups of gases, such as toxic gases or combustible gases.The gas detection element 24 detects the gas present in the chamber 21 and generates a detection signal generated in response to the gases present in the chamber 21. If a chemoresistive gas sensor array is used, the detection signal is based on the resistance value generated by the interaction between the gas and the sensor array [e.g. a change from 0 to a specific value] or the change in the resistance value [e.g. a change from a first initial value to a second value]. The detection signal may be used for obtaining judgment information regarding the ambient gas. This assessment information can comprise, for example, the presence of one or more specific constituents in the ambient gas, the concentration or amount of these constituents [or the reaching of a specific threshold value], the correspondence of the ambient gas with a predefined composition or changes in specific constituents, compositions or concentrations in the ambient gas.The environment detection element 25 serves to detect one or more environmental parameters within the chamber 21, which environmental parameters may comprise temperature, air humidity, pressure, air pressure or any combination of the aforementioned factors. Referring to FIG. 3, depending on the environmental parameters to be detected, the environment detection element 25 may include a temperature detection element 251, a humidity detection element 252, a pressure sensor element 253, or any combination of these components. The temperature detection element 251, the humidity detection element 252, and the pressure sensor element 253 are provided for measuring the temperature, the humidity, and the pressure inside the chamber 21, respectively.The control system 50 controls switching and adjustment of the first fluid control device 13 and the second fluid control device 231, and also controls switching on and off of the suction unit 40. By controlling the first fluid control device 13 and the second fluid control device 231 via the control system 50, two different gas flow modes can be selectively executed: circulating flow and single flow.In the circulating flow mode, the gas returns from the outlet 211 of the chamber 21 via the circulating passage 23 [by opening the first opening 232 and the second opening 233 of the second fluid control device 231 while closing the third opening 234 of the second fluid control device 231] and enters the chamber 21 again via the inlet 210 [by opening the second opening 132 and the third opening 133 of the first fluid control device 13 while closing the first opening 131 of the first fluid control device 13].In the single flow mode, there is no recirculation of the gas. The gas enters through the air inlet opening 11, flows into the chamber 21 via the inlet 210 [by opening the first opening 131 and the third opening 133 of the first fluid control device 13 while simultaneously closing the second opening 132 of the first fluid control device 13], and is then discharged through the gas outlet 14 via the outlet 211 of the chamber 21 [by opening the first opening 232 and the third opening 234 of the second fluid control device 231 while simultaneously closing the second opening 233 of the second fluid control device 231].In the exemplary embodiment shown in FIG. 3, the electronic nose 2 is integrated into the robot 1 as an independent module. The control system 50 may be additionally connected to a control unit 60 of the robot 1. The control unit 60 may include a processor 61, a database 62, and a communication interface 63. The control unit 60 may serve to control the control system 50, receive signals from the control system 50, or as a connection path between the electronic nose 2 and other external components. In one embodiment, the processor 61 may receive and process the detection signal generated by the gas detection element 24 as well as the environmental parameters detected by the environmental detection elements 25. This can be done, for example, by matching the detection signal with the reference data stored in the database 62 in order to generate an analysis with respect to the ambient gas. In another embodiment, the processor 61 may be configured as a unit capable of performing calculations using artificial intelligence [AI] so that the robot 1 may locally perform generative AI processing of the detected detection signals and / or environmental parameters. In other embodiments, the control unit 60 may be connected to an external device 70, such as a server or an external database, via the transmission interface 63. The transmission interface 63 may include wired or wireless communication hardware compatible with one or more of the following protocols: WiFi, BLE [Bluetooth Low Energy], Bluetooth, Z-Wave, USB, or Zigbee. It is to be understood that in further exemplary embodiments, the control unit 60 can alternatively also be embodied as an integrated unit within the module of the electronic nose 2, without being limited to the above-mentioned configuration.During operation of the electronic nose 2, the operation of the suction unit 40 is among the major factors of energy consumption. If the suction unit 40 remains permanently activated throughout the operation of the electronic nose 2 to continuously supply ambient gas into the chamber 21, this results in a high energy consumption, which shortens the operating time of the electronic nose 2 and at the same time reduces the service life of the suction unit 40. Therefore, according to the invention, an operating mode of the electronic nose 2 is provided, which can be switched between a monitoring mode and an identification mode. The monitoring mode represents an operating phase with lower detection accuracy but lower energy consumption, while the identification mode is a phase with higher detection accuracy but higher energy consumption. In one embodiment, the electronic nose 2 operates primarily in the monitoring mode during normal operation and remains continuously in this mode. Only when the electronic nose 2 detects a change in the ambient gas composition which requires a more accurate analysis does it enter the identification mode.The monitoring mode consists of several cycles, which are composed of a combination of waiting time phases and short-term air inlet phases. The electronic nose 2 remains in the monitoring mode until the detection signal detected during a short-term air intake phase meets a predefined specific criterion. In this case, a transition [or a switchover] to the identification mode takes place. The identification mode comprises a long-term air inlet phase followed by a subsequent detection phase within a single cycle. It is to be understood that the term "short-term" is to be considered in relation to "long-term". Within the individual operating modes, the respective time parameters can be either identical or different. For example, the waiting time can be longer than the duration of the short-term air inlet phase. By specifically adapting the continuous conditions between the short-term and long-term air inlet phases and the relationship between the waiting time and the short-term air inlet duration, the total operating time of the suction unit 40 during the detection by the electronic nose 2 can be significantly reduced. This leads not only to a significant saving of energy, but also to a prolonged service life of the suction unit 40.In a subsequent exemplary embodiment, the gas detection element 24 is designed as a chemoresistive gas sensor, the detection signal being present as a resistance value. Referring to FIG. 4 illustrating the operation of the electronic nose 2, as well as in combination with FIGS. 5 and 6, the electronic nose 2 operates in the monitoring mode in the normal operation, and only switches to the identification mode when the predefined specific criterion is satisfied. In this embodiment, before entering the monitoring mode, an operation phase in the circulating flow mode is first performed with the cleaning unit 30 activated [i.e., the light emitting element 32 turned on]. In this phase, the gas continuously and repeatedly flows through the chamber 21 via the circulation passage 23 until the resistance value detected by the gas detection element 24 reaches a stable state [process step 80]. Only then does the electronic nose 2 change to the monitoring mode. The purpose of process step 80 is to clean the chamber 21 and / or establish an equilibrium state within the chamber 21 before the actual detection. Since the gas initially flows through the carrier 31 before entering the chamber 21, the gas which reaches the vicinity of the gas detection element 24 is cleaned beforehand.Subsequently, the electronic nozzle 2 switches to the monitoring mode in which the gas flow is in the single flow mode. During this mode, the electronic nose 2 cycles through an operation composed of waiting periods and brief air intake periods. During the waiting time, both the suction unit 40 and the lighting element 32 remain deactivated. As a result, no gas flows into the chamber 21, and no detection takes place. During the short-term air inlet phase, the suction unit 40 is activated, while the lighting element 32 continues to remain switched off. In this state, the circulation channel 23 remains closed, so that the ambient gas to be detected reaches the chamber 21 from the air inlet opening 11 via the inlet 210 and, after flowing through the carrier 31 and the gas detection element 24 [process step 81], is discharged via the outlet 211 of the chamber 21 and the gas outlet 14. Since the light-emitting element 32 is deactivated, the gas is detected by the gas-detection element 24 in the untreated state. As soon as the gas passes the gas detection element 24, it is detected and analyzed [process step 82].FIG. 5 illustrates the change over time of the resistance change value ΔRs of the gas detection element 24 in the monitoring mode. The resistance change value ΔRs is calculated according to the equation: where R st represents the resistance value at time t and R st-1 represents the resistance value at the previous time t-1. The time interval between t and t-1 can be selected according to requirements. The monitoring mode consists of a plurality of waiting time cycles Ts waiting time phase and a plurality of detection time cycles Td short-term air inlet phase. The detection time cycle Td directly follows the waiting time cycle Ts. During the waiting time cycles Ts, the suction unit 40 remains inactive, so that no air is suctioned off. The extraction takes place only during the shorter detection time cycles Td. In other words, during the waiting time cycles Ts, no ambient gas reaches the chamber 21, so that the change in resistance ΔRs remains very small, as can be seen in FIG. 5 on the basis of the five Ts sections. During the detection time cycles Td, ambient gas is introduced into the chamber 21, resulting in a change in resistance, as shown in Figure 5 by the five Td sections.If the resistance change ΔRs caused by the ambient gas is small or is below a defined threshold value, the electronic nose 2 continues to remain in the monitoring mode [process step 83], as illustrated in FIG. 5 with reference to the first four Td sections. However, if the resistance change ΔRs caused by the ambient gas is large or exceeds the defined threshold value, the electronic nose 2 shifts to the identification mode as illustrated in FIG. 5 with reference to the fifth Td portion [process step 84]. In one embodiment, the duration of the detection time cycle Td is shorter than the duration of the wait time cycle Ts. In a further exemplary embodiment, the ratio of the duration of the detection time cycle Td to the duration of the waiting time cycle Ts is between 0 and 1, for example less than 1 / 5, 1 / 10 or 1 / 15.FIG. 6 shows the time variation of the resistance value Rs in the identification mode. The identification mode comprises two phases: a prephase P 1 and a detection phase P 2. In the pre-phase P 1, the control system 50 controls the gas flow in the circulating flow mode while the cleaning unit 30 is activated, the light emitting element 32 is turned on. As a result, the purified ambient gas [clean gas] is guided into the outlet region 21 bof the chamber 21 [process step 84]. However, this clean gas does not represent the gas to be detected, but can be considered as background gas, reference gas or cleaning medium, which serves to stabilize the chamber 21 before detection. In certain aspects, the pre-phase P 1 may also be interpreted as a pre-cleaning phase. If the carrier 31 contains both a photocatalyst and activated carbon, the duration of the prephase P 1 and of the process step 80 can be further shortened compared to a configuration with only photocatalyst.The control system 50 receives the detection signal generated by the gas detection element 24 and the environmental parameters detected by the environmental detection elements 25 and checks on the basis of these values whether the state of equilibrium has been reached [process step 84]. The equilibrium state is defined as the state in which the detection signal and one or more of the environmental parameters within the chamber 21 have reached a stable equilibrium value. The environmental parameters may include temperature, humidity, and / or pressure. It is understood that the equilibrium state can be achieved by either stabilizing a single environmental parameter [e.g., only temperature] or multiple environmental parameters. The more environmental parameters have a stable state, the more favorable this is for reliable detection. Reaching the equilibrium value means that the detection signal and the environmental parameters within the chamber 21 remain substantially constant. In one exemplary embodiment, this can be interpreted in such a way that the values remain virtually unchanged over time, for example within a specific tolerance range around a reference value. This tolerance can be, for example, ±10%, ±5% or ±1%. The control system 50 may determine the equilibrium state being reached by checking whether the resistance value as well as the environmental parameters temperature, humidity, pressure, or a combination of these values remain constant within the defined threshold for a predefined period of time. In other words: the equilibrium state is defined as a phase within the prephase P 1, in which the detection signal and the environmental parameters remain substantially constant continuously over a specific period of time. In one embodiment, the exhaust unit 40 is controlled so that the flow rate of the clean gas entering the chamber 21 is substantially constant. A stable gas flow within the chamber 21 helps to reach equilibrium in a shorter time.As illustrated in FIG. 6, in the prephase P 1, the resistance value of the detection signal generated by the gas detection element 24 gradually increases with time, and reaches a stable state at a first resistance value R 1 time T 1. At this time, the equilibrium state is reached. The period from the start of the prephase P 1 to the time T 1 is referred to as a first time period.As soon as the equilibrium state is reached, the system changes to the detection phase P 2 [process step 85]. In this exemplary embodiment, the suction unit 40 continues to be activated during the transition from the prephase P 1 to the detection phase P 2. At the same time, the control system 50 adjusts the first fluid control device 13 and the second fluid control device 231 so that the gas flow is in the single flow mode. At the same time, the cleaning unit 30 is deactivated [the light element 32 is switched off]. In this way, the gas flowing through the outlet portion 21b after entering the chamber 21 is the untreated ambient gas to be detected. The suction unit 40 remains activated continuously. In the pre-phase P 1, the first opening 232 and the second opening 233 of the second fluid control device 231 are opened, while the third opening 234 is closed. At the same time, the second opening 132 and the third opening 133 of the first fluid control device 13 are opened, while the first opening 131 is closed. In the detection phase P 2, the first opening 131 and the third opening 133 of the first fluid control device 13 are opened, while the second opening 132 is closed. At the same time, the first opening 232 and the third opening 234 of the second fluid control device 231 are opened, while the second opening 233 is closed.As illustrated in FIG. 6, depending on the type of the gas flowing through the gas detection element 24, the resistance value of the detection signal generated by the gas detection element 24 changes from the first resistance value R 1 to a second resistance value R 2. After a certain time, it stabilizes at R2 time T2, the time period from T1 to T2 being defined as the second time period. The second resistance R2represents the response of the gas sensing element 24 to one or more characteristics of the untreated ambient gas. The control system 50 receives the detection signal generated by the gas detection element 24 and the environmental parameters detected by the environmental detection elements 25 [process step 86], and determines the assessment information on the basis of the detection signal. In one embodiment, all detection is under room temperature conditions, i.e., the gas within chamber 21 is not heated. However, the present invention is not limited thereto. In certain exemplary embodiments, the detection can also be effected with heating of the gas within the chamber 21.In one embodiment, the equilibrium state refers more particularly to the state within chamber 21 where the gas is in motion [i.e., is in the form of a gas flow rather than a stationary gas]. In a further exemplary embodiment, the suction unit 40 remains activated continuously during the transition from the prephase P 1 to the detection phase P 2. Thereby, the gas is continuously [continuously] introduced into the chamber 21 either from the circulation channel 23 or from the outside. In one embodiment, the purified circulating gas within chamber 21 forms a first flowing gas phase, while the untreated ambient gas within chamber 21 forms a second flowing gas phase. The first gas flow in the prephase P 1 and the second gas flow in the detection phase P 2 have a substantially identical flow velocity. Since the suction unit 40 is not deactivated during the transition from the prephase P 1 to the detection phase P 2, the gas flow in the chamber 21 is constantly maintained, wherein only the composition of the flowing gas changes. As a result, the environmental parameters within the chamber 21 change only to a slight extent, so that the equilibrium state is only minimally influenced or disturbed. This avoids re-establishing the equilibrium state in the chamber 21, whereby the measurement accuracy can be increased and the measurement time can be shortened. Under these operating conditions, the equilibrium state may be interpreted as a dynamic equilibrium.According to the invention, the need to maintain the stability of the detection environment, i.e. to ensure the equilibrium state, during the introduction and detection of the ambient gas to be analyzed in order to obtain precise measurement results is taken into account. Therefore, before the introduction of the untreated gas to be detected, it is first ensured that the chamber 21 remains in dynamic equilibrium. This means that, when the gas is flowing, all environmental parameters remain substantially constant. Subsequently, without interrupting the gas flow, the supply of the untreated gas to be detected is switched over. In this way, the flow velocity of the gas within the chamber 21 remains substantially constant. In other words, the gas pressure in the chamber 21 remains substantially unchanged in both phases.In certain embodiments of the present invention, the equilibrium state does not necessarily have to be present as a dynamic equilibrium, but can also be achieved as a static equilibrium. The difference in operating mode is that after completion of the prephase P 1, the suction unit 40 is first deactivated, so that the detection signal and the environmental parameters in the chamber 21 reach an equilibrium state under conditions without gas flow, before the transition is made to the detection phase P 2. According to one embodiment of the present invention, the electronic nose 2 can be selectively operated in the dynamic or static equilibrium mode.The electronic nose 2 of the present invention is designed to operate continuously in the monitoring mode during normal operation and to switch to the identification mode only while satisfying specific criteria. In the monitoring mode, the operating time of the suction unit 40 is substantially shorter than its deactivated time, whereby the energy consumption is substantially reduced and at the same time the service life of the suction unit 40 is extended. Moreover, the electronic gas cleaning technology used in the present invention allows elimination of replacement and storage problems. In addition, it can be flexibly combined with different operating modes [monitoring mode, identification mode] or operating phases [prephase P 1, detection phase P 2] in order to more efficiently carry out the automated gas recognition.In summary, an electronic quick detection nose is disclosed, which includes an air inlet unit 10, a detection unit 20, a cleaning unit 30, an exhaust unit 40 and a control system 50. The air intake unit 10 is configured to introduce an ambient gas. The detection unit 20 includes a chamber 21, a circulation line 22, and a detection module, wherein the circulation line 22 is for conveying a circulating gas flow to clean the chamber 21, while the air inlet unit 10 is used for conveying the ambient gas to be detected. The cleaning unit 30 is arranged inside the chamber 21 and comprises a support 31, a photocatalyst and a light emitting element 32, and the suction unit 40 is connected to the circulation line 22 to generate a negative pressure in the chamber 21 and to initiate the circulating gas flow. The control system 50 is connected to the detection module 20 and receives the detection signal generated by the detection module 20.

Claims

An electronic nose for a robot, comprising: an air inlet unit (10) configured to introduce an ambient gas; a detection unit (20) comprising a chamber (21), a circulation line (22) and a detection module, wherein an inlet (210) of the chamber (21) communicates with the air inlet unit (10) and jointly defines an air inlet duct (12), wherein the circulation line (22) is connected to an outlet (211) of the chamber (21) and the inlet (210) and forms a circulation duct (23), and wherein the detection module comprises a gas detection element (24) and one or more ambient detection elements (25), and wherein the gas detection element (24) is for detecting the gas present in the chamber (21) and for generating a detection signal in response to the gas present in the chamber (21), and wherein the environment detection element (25) is for detecting one or more environmental parameters within the chamber (21), and wherein the circulation channel (23) is configured to transport a circulating gas flow for cleaning the chamber (21), and the air inlet channel (12) is configured to convey the environmental gas to be detected; a cleaning unit (30) arranged within the chamber (21) and through which the circulating gas flow is passed, wherein the cleaning unit (30) comprises a carrier (31), a photocatalyst arranged on the carrier (31) and a light element (32) emitting light onto the photocatalyst arranged on the carrier (31); a suction unit (40) connected to the circulation line (22) to guide the gas inside the chamber (21) from the outlet (211) back to the inlet (210); and a control system (50) connected to the detection module and receiving the detection signal generated by the detection module, wherein the control system (50) determines judgment information related to the surrounding gas based on the detection signal generated by the surrounding gas introduced into the chamber (21) via the air inlet duct (12).Electronic nose according to claim 1, characterized in that the electronic nose (2) is configured to perform the following steps: step 1-1: At periodic time intervals of a waiting time period, the entry of the ambient gas into the chamber (21) via the air inlet duct (12) is allowed, wherein the supply of the gas takes place over a detection time period which is shorter than the waiting time period; step 1-2: The execution of step 1-1 is repeated until the detection signal corresponds to a predefined specific criterion; step 1-3: Once the specific criterion is fulfilled, the air inlet duct (12) is closed and the circulation duct (23) is opened, so that the gas contained in the chamber (21) is discharged via the outlet (211) and passes through the circulation duct (23) and the inlet (210) again into the chamber (21), thereby forming the circulating gas flow. This operation is continued until the detection signal and environmental parameters have reached a steady state; and step 1-4: The circulation channel (23) is closed and the air inlet channel (12) is opened, so that the environmental gas enters the chamber (21) via the air inlet channel (12). Based on the detection signal generated by the ambient gas introduced into the chamber (21), the judgment information is determined.The electronic nose according to claim 2, characterized in that the light emitting element (32) is turned on in step 1-1 and step 1-3 while being turned off in step 1-4.Electronic nose according to claim 2 or 3, characterised in that the specific criterion consists in the variation of the detection signal generated by the gas detection element (24) during the detection time period reaching a threshold value.Electronic nose according to any of claims 2 - 4, characterized in that the suction unit (40) is deactivated during the waiting time period and is activated during the detection time period.Electronic nose according to any of the preceding claims, characterized in that the environmental parameters are selected from a group consisting of a temperature, an air humidity, an air pressure inside the chamber (21) and combinations thereof.Electronic nose according to one of the preceding claims, characterized in that the gas detection element (24) is a chemoresistive gas sensor and the detection signal is a resistance value.Electronic nose according to one of the preceding claims, characterized in that the environment detection element (25) is selected from a group consisting of a temperature detection element (251), a moisture detection element (252), a pressure sensor element (253) and combinations thereof.Electronic nose according to any of the preceding claims, characterized in that the electronic nose (2) is configured to perform the following steps: step 2-1: The air inlet duct (12) is closed and the circulation duct (23) is opened, so that the gas located in the chamber (21) is discharged via the outlet (211) and conducted back into the chamber (21) via the circulation duct (23) as well as the inlet (210), thereby forming a circulating gas flow. This operation is continued until the detection signal and environmental parameters have reached a steady state; and step 2-2: The circulation channel (23) is closed and the air inlet channel (12) is opened, so that the environmental gas flows into the chamber (21) via the air inlet channel (12). Based on the detection signal generated by the ambient gas introduced into the chamber (21), judgment information regarding the ambient gas is determined.Electronic nose according to claim 9, characterised in that the lighting element (32) is switched on in step 2-1 and is switched off in step 2-2.Electronic nose according to claim 9 or 10, characterised in that the equilibrium state is that the detection signal and the environmental parameters remain substantially constant continuously during a defined time interval.Electronic nose according to any one of the preceding claims, characterized in that the cleaning unit (30) additionally comprises activated carbon arranged on the support (31).A robot comprising: a robot structure (1a); and an electronic nose (2) according to any one of claims 1 to 12 disposed on the robot structure (1a) and communicating with the environment.

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