US12251991B2

US12251991B2 - Humidity control for olfaction sensors

Info

Publication number: US12251991B2
Application number: US17/218,580
Authority: US
Inventors: Sibu VARUGHESE; Martín NESPOLO; Thomas Krzyzak; Gareth Webb; Wilson YIM; Matthew Johnson
Original assignee: Denso International America Inc
Current assignee: Denso International America Inc
Priority date: 2020-08-20
Filing date: 2021-03-31
Publication date: 2025-03-18
Also published as: US20220055458A1

Abstract

A vehicle system includes: an olfaction sensor comprising: a blower configured to draw air through an inlet; a dehumidifier configured to decrease a humidity of the air; and a sensor located downstream of the dehumidifier and configured to measure an amount of a chemical in the air after the air flows through the dehumidifier; and a control module configured to selectively take one or more remedial actions based on the amount of the chemical in the air measured by the sensor.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 63/067,918, filed on Aug. 20, 2020. The entire disclosure of the application referenced above is incorporated herein by reference.

FIELD

The present disclosure relates to vehicles and more particularly to systems and methods for controlling humidity for olfaction sensors.

BACKGROUND

This section provides background information related to the present disclosure which is not necessarily prior art.

Vehicles have been recalled due to carbon monoxide entering their passenger cabins and for other reasons. Humans may be overcome by carbon monoxide and lose consciousness.

There may be numerous other situations where chemicals could be present within a passenger cabin of a vehicle. For example, a user may bring an aerosol can in to the passenger cabin of a vehicle and forget to take it out. Due to heat or cold, the aerosol can could emit its contents into the passenger cabin. One or more users could enter the vehicle later and breathe the contents without knowledge.

Electric vehicles include one or more batteries that contain chemicals, such as lithium. The batteries may be located under the passenger cabin and, under some circumstances, can rupture and emit chemicals. Some chemicals that may be present within a passenger cabin of a vehicle may be odorless and colorless.

SUMMARY

In a feature, a vehicle system includes: an olfaction sensor comprising: a blower configured to draw air through an inlet; a dehumidifier configured to decrease a humidity of the air; and a sensor located downstream of the dehumidifier and configured to measure an amount of a chemical in the air after the air flows through the dehumidifier; and a control module configured to selectively take one or more remedial actions based on the amount of the chemical in the air measured by the sensor.

In further features, the dehumidifier includes a desiccant that decreases the humidity of the air.

In further features, the dehumidifier includes a heat exchanger that decreases the humidity of the air.

In further features, the dehumidifier includes a dry filter through which the air flows that decreases the humidity of the air.

In further features, the dry filter is configured to filter droplets of moisture from the air as the air flows through the dry filter.

In further features, the dehumidifier includes a condenser that cools the air as the air flows through the condenser and that decreases the humidity of the air.

In further features, the dehumidifier includes a freezer that cools the air as the air flows through the freezer and that decreases the humidity of the air.

In further features, the dehumidifier includes a heater that warms the air as the air flows through the dehumidifier and that decreases the humidity of the air.

In further features, the dehumidifier includes a burner that decreases the humidity of the air.

In further features, the dehumidifier includes a glass tube through which the air travels that dehydrates the air.

In further features, the control module is configured to selectively take the one or more remedial actions when the amount of the chemical in the air measured by the sensor is greater than a predetermined value.

In further features, the control module is configured to, based on the amount of the chemical in the air measured by the sensor, selectively open at least one window of the vehicle.

In further features, the control module is configured to, based on the amount of the chemical in the air measured by the sensor, selectively at least one of: turn on a blower of a heating ventilation and air conditioning system; and increase a speed of the blower.

In further features, the blower is configured to draw air through the sensor and the dehumidifier.

In further features, the blower is configured to blow air through the sensor and the dehumidifier.

In further features, the blower is configured to draw air through the dehumidifier and blow air through the sensor.

In further features, the chemical is one of volatile organic compounds (VOCs), particulate matter, and carbon monoxide.

In further features, the dehumidifier includes a Peltier device.

In further features, the dehumidifier includes: a charger configured to charge water to have one of (a) a positive polarity and (b) a negative polarity; and a plate configured to attract water and having the other one of (a) a positive polarity and (b) a negative polarity.

In a feature, a method includes: drawing draw air through an inlet of an olfaction sensor using a blower; decreasing a humidity of the air by a dehumidifier; and downstream of the dehumidifier, by a sensor, measuring an amount of a chemical in the air after the air flows through the dehumidifier; and selectively taking one or more remedial actions based on the amount of the chemical in the air measured by the sensor.

Further areas of applicability of the present disclosure will become apparent from the detailed description, the claims and the drawings. The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.

DRAWINGS

The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

FIG. 1 is a functional block diagram of an example vehicle system.

FIGS. 2-4 are functional block diagrams of example olfaction sensors.

FIG. 5 is a perspective view of an example of a dehumidifier of an olfaction sensor.

FIG. 6 is a functional block diagram of an example control system.

Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION

Example embodiments will now be described more fully with reference to the accompanying drawings.

A vehicle may include an olfaction sensor that measures the amount of a chemical within a passenger cabin of the vehicle. Examples of olfaction sensors include VOC sensors, carbon monoxide sensors, and particulate sensors.

Olfaction sensors may be sensitive to humidity. In other words, the measurements of olfaction sensors may be affected by humidity. For example, despite the same amount of a chemical being present in air, the measurements of some types of olfaction sensors may increase as humidity increases and vice versa. As another example, despite the same amount of a chemical being present in air, the measurements of some types of olfaction sensors may decrease as humidity increases and vice versa. Humidity in air samples may therefore affect the accuracy of measurements of olfaction sensors. Additionally, high humidity may decrease lifetimes of olfaction sensors.

According to the present application, the olfaction sensor includes a dehumidifier that decreases humidity of air before the air reaches a sensor configured to measure the amount of the chemical in the air. This increases the accuracy of the measurements of the sensor and increases a lifetime of the sensor.

FIG. 1 includes a functional block diagram including an example vehicle 5. The vehicle 5 includes a control module 8 and one or more olfaction sensors, such as olfaction sensor 10. Examples of olfaction sensors in vehicles include, for example, particulate matter sensors, carbon monoxide (or other carbon oxide) sensors, volatile organic compound (VOC) sensors, and other types of sensors. The vehicle 5 may include one or more different types of olfaction sensors.

The olfaction sensor(s) are each configured to measure an amount of one or more chemicals within a passenger cabin of the vehicle 5. For example, the vehicle 5 may include a particulate matter sensor configured to measure one or more amounts (e.g., concentrations or mass flow rates) of particulate of one or more different sizes in air within the passenger cabin. Additionally or alternatively, the vehicle 5 may include a carbon monoxide sensor configured to measure an amount (e.g., concentration) of carbon monoxide in air within the passenger cabin. Additionally or alternatively, the vehicle 5 may include a VOC sensor configured to measure an amount (e.g., concentration) of VOCs within the passenger cabin.

The control module 8 may receive the measurements from the olfaction sensor(s) and take one or more remedial actions based on the measurements. For example, when one or more amount of one or more chemicals (e.g., particulate, carbon monoxide, VOCs) measured by one or more olfaction sensors is/are greater than one or more respective predetermined amount/s (e.g., of particulate matter, carbon monoxide, or VOCs, respectively), the control module 8 may take one or more remedial actions. The predetermined amount/s is/are greater than zero.

For example, the control module 8 may open one or more windows 12 of the vehicle 5 when the amount of a chemical is greater than the predetermined amount. Additionally or alternatively, the control module 8 may generate an alert within the vehicle 5 when the amount of a chemical is greater than the predetermined amount. For example, the control module 8 may generate or display a visual alert, such as via a visual indicator 14 that is visible within the passenger cabin of the vehicle 5. The visual indicator 14 may be, for example, one or more indicator lights, a display, or another suitable type of visual indicator. Additionally or alternatively, the control module 8 may output an audible alert, such as via one or more speakers. Additionally or alternatively, the control module 8 may output a tactile alert, such as via turning on one or more vibrating devices, such as located in one or more seats, in a steering wheel, or in another suitable location.

Additionally or alternatively, the control module 8 may turn on a heating ventilation and air conditioning (HVAC) system 16 of the vehicle 5 when the amount of a chemical is greater than the predetermined amount. The control module 8 may, for example, turn on a blower of the HVAC system 16 and control one or more actuators of the HVAC system 16 to recirculate air from within the passenger cabin to outside of the passenger cabin. This is discussed in more detail below.

Additionally or alternatively, the control module 8 may store an indicator in memory of the vehicle when the amount of a chemical is greater than the predetermined amount. The indicator may indicate that the amount of the chemical was greater than the predetermined amount. The control module 8 may also store a time stamp (e.g., including a date and a time of the occurrence) with the indicator.

Additionally or alternatively, the control module 8 may transmit an indicator to a remote device 20, such as of a fleet operator, when the amount of a chemical is greater than the predetermined amount. The control module 8 may transmit the indicator via one or more communication networks, such as a cellular communication network, a satellite communication network, a Wi-Fi communication network, or another suitable type of communication network.

FIG. 2 is a functional block diagram of an example implementation of an olfaction sensor 100. The olfaction sensor 100 may be implemented within the HVAC system 16 or in another location within the passenger cabin of the vehicle 5. As discussed above, the vehicle 5 may include multiple olfaction sensors.

According to the present application, the olfaction sensor 100 includes a dehumidifier 104 that decreases humidity of air before one or more amounts of one or more chemicals in the air is/are measured by one or more sensor 108. This increases the accuracy of the measurements of the sensor 108 and increases a lifetime of the sensor 108.

The sensor 108 includes one or more sensors configured to measure one or more amounts of one or more chemicals in air at the sensor 108. For example, the sensor 108 may include one or more particulate matter sensors, one or more VOC sensors, one or more carbon monoxide sensors, and/or one or more other types of olfaction sensors.

The olfaction sensor 100 includes an inlet 112, an outlet 116, and a blower 120. The blower 120 draws air through the inlet 112 for measurement by the sensor 108 after dehydration by the dehumidifier 104. The blower 120 may draw the air through the sensor 108 (and the dehumidifier 104) as shown in FIG. 2 . Other example blower locations are provided in FIGS. 3 and 4 . In the example of FIG. 3 , the blower 120 blows air through both the sensor 108 and the dehumidifier 104. In the example of FIG. 4 , the blower 120 draws air through the dehumidifier 104 and blows air through the sensor 108. After measurement by the sensor 108, the air is output from the olfaction sensor 100 via the outlet 116. A housing of the olfaction sensor 100 is denoted by 124.

While only one dehumidifier 104 is shown for simplicity, the dehumidifier 104 may include one or more dehumidifiers. For example, the dehumidifier 104 may include one or more desiccant (e.g., in pack/bag form or material form) that remove humidity from the air. The desiccant is used as a humidity filter to remove humidity from the air provided to the sensor 108.

As another example, the dehumidifier 104 may include a dehumidifier that compresses the air (using a compressor) and removes condensation from the compressed air (using a condenser) before outputting the air to the sensor 108.

As another example, the dehumidifier 104 may include a dry filter through which the air is drawn. The dry filter acts as a screen and collects moisture from the air. The dry filter may be, for example, a cellulose filter paper or another suitable type of dry filter. In various implementations, the dehumidifier 104 may include an oiled filter. Moisture may accumulate and be drained (e.g., via gravity) from the dehumidifier 104.

In addition to the dry filter, the dehumidifier 104 may include a charged water remover. A charge of water droplets may be made positive or negative, such as by an ionizer. A plate (e.g., a metal plate) charged oppositely to the charge of the water droplets may attract water from the air to dehumidify the air.

As another example, the dehumidifier 104 may include a condenser that cools the air such that air condensates on interior walls (e.g., of the dehumidifier 104 and/or the sensor 108). As another example, the dehumidifier 104 may include a freezer that cools the air such that condensation freezes on interior walls (e.g., of the dehumidifier 104 and/or the sensor 108).

As another example, the dehumidifier 104 may include a heater and/or a burner. The heater may be, for example, an electrical (resistive) heater that generates heat when power is applied to the heater. The burner may, for example, burn fuel, such as a combustible gas, to generate heat. Heating of the air (e.g., via a heater or a burner) may decrease humidity of the air before the air enters the sensor 108.

As another example, the dehumidifier 104 may include a medium in which the air travels that dehydrates the air. An example is shown in FIG. 5 . For example, the dehumidifier 104 may include a condenser tube 400 through which the air is drawn or blown. The dehumidifier 104 may cool the glass of the condenser tube, and the cooling may condensate water from the air before the air is input to the sensor 108. In the example of FIG. 5 , cool air may be input to the dehumidifier and flow through a coiled tube 404 within the condenser tube 400. Alternatively, heated air may be used to dehumidify the air before the air is input to the sensor 108. While the example of FIG. 5 illustrates the drying air flowing through the coiled tube 404 and the air to be dehumidified flowing through the condenser tube 400, the drying air may alternatively flow through the condenser tube 400 and the air to be dehumidified may flow through the coiled tube 404.

As another example, the dehumidifier 104 may include a Peltier device. The Peltier device may perform thermoelectric heating or cooling to dehumidify the air.

FIG. 6 is a functional block diagram of an example implementation of a control system. As discussed above, one or more olfaction sensors may be included, such as at least one of a VOC sensor, a particulate matter sensor, and a carbon monoxide sensor. The olfaction sensor 100 of FIG. 6 may be a VOC sensor, a particulate matter sensor, or a carbon monoxide sensor. In various implementations, the olfaction sensor 100 may include two or more of a VOC sensor, a particulate matter sensor, and a carbon monoxide sensor.

A comparison module 504 compares a measurement from the olfaction sensor 100 with a predetermined value and generates an output signal based on the comparison. The measurement may be, for example, an amount of particulate, an amount of VOCs, or an amount of carbon monoxide. The comparison module 504 may set the output signal to the first state when the measurement is less than the predetermined value and set the output signal to a second state when the measurement is greater than or equal to the predetermined value.

The comparison module 504 may obtain the predetermined value from memory 508. The predetermined value is greater than zero and may be a fixed predetermined value. Alternatively, the predetermined value may be variable. For example, a baseline module 512 may determine a baseline value and set the predetermined value to the baseline value. The baseline module 512 may set the baseline value, for example, based or equal to an average of the measurements from the olfaction sensor 100 taken over a predetermined period, such as a week or a month. An average may be determined by summing the measurements and dividing by the number of measurements summed.

One or more remedial actions may be taken when the output signal of the comparison module 504 is in the second state. For example, a window actuator module 516 controls actuation (opening and closing) of one or more window actuators, such as window actuator 520, of the vehicle. The window actuator 520 opens (e.g., lowers) and closes (e.g., raises) a window of the vehicle. The window actuator module 516 may control one or more window actuators to open one, more than one, or all of the windows of the vehicle when the output signal of the comparison module 504 is in the second state. Opening the window(s) may include, for example, opening the window(s) to a partially open position further than the window(s) is/are presently open or opening the window(s) to a fully open position.

Additionally or alternatively, an alert module 524 may generate an alert (e.g., visually the visual indicator 14, audibly via one or more speakers, and/or haptically via one or more vibrating devices) when the output signal of the comparison module 504 is in the second state. Additionally or alternatively, a blower control module 528 may turn on a blower 532 of the HVAC system when the output signal of the comparison module 504 is in the second state.

Additionally or alternatively, a communication module 540 may wirelessly transmit an indicator to the remote device 20 via one or more antennas 544 when the output signal of the comparison module 504 is in the second state. Additionally or alternatively, a storage module 548 may store an indicator in the memory 508 when the output signal of the comparison module 504 is in the second state. The indicator may indicate that the amount of the chemical was greater than the predetermined value. The storage module 548 may also store a time stamp (e.g., including a date and a time of the occurrence) with the indicator. A clock 552 may track the date and time.

The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

In this application, including the definitions below, the terms “module” and “system” may refer to, be part of, or include circuits or circuitry that may include processor hardware (shared, dedicated, or group) that executes code and memory hardware (shared, dedicated, or group) that stores code executed by the processor hardware. The code is configured to provide the features of the modules and systems described herein. In addition, in this application the terms “module” and “system” may be replaced with the term “circuit.” The term “memory hardware” may be a subset of the term computer-readable medium. The term computer-readable medium does not encompass transitory electrical and electromagnetic signals propagating through a medium, and may therefore be considered tangible and non-transitory. Non-limiting examples of a non-transitory tangible computer readable medium include nonvolatile memory, volatile memory, magnetic storage, and optical storage.

The apparatuses and methods described in this application may be partially or fully implemented by a special purpose computer created by configuring a general purpose computer to execute one or more particular functions embodied in computer programs. The functional blocks, flowchart components, and other elements described above serve as software specifications, which can be translated into the computer programs by the routine work of a skilled technician or programmer.

The computer programs include processor-executable instructions that are stored on at least one non-transitory, tangible computer-readable medium. The computer programs may also include or rely on stored data. The computer programs may encompass a basic input/output system (BIOS) that interacts with hardware of the special purpose computer, device drivers that interact with particular devices of the special purpose computer, one or more operating systems, user applications, background services, background applications, etc.

The computer programs may include: (i) descriptive text to be parsed, such as JavaScript Object Notation (JSON), hypertext markup language (HTML) or extensible markup language (XML); (ii) assembly code; (iii) object code generated from source code by a compiler; (iv) source code for execution by an interpreter; (v) source code for compilation and execution by a just-in-time compiler, etc. As examples only, source code may be written using syntax from languages including C, C++, C#, Objective C, Haskell, Go, SQL, R, Lisp, Java®, Fortran, Perl, Pascal, Curl, OCaml, Javascript®, HTML5, Ada, ASP (active server pages), PHP, Scala, Eiffel, Smalltalk, Erlang, Ruby, Flash®, Visual Basic®, Lua, and Python®.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.

When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

Claims

What is claimed is:

1. A vehicle system, comprising:

an olfaction sensor assembly comprising:

a housing including an inlet;

a blower disposed within the housing and configured to draw air through the inlet,

the blower separate from a second blower of a heating, ventilation, and air conditioning (HVAC) system of the vehicle;

a dehumidifier disposed within the housing configured to decrease a humidity of the air; and

a sensor disposed within the housing and located directly downstream of the dehumidifier and configured to measure an amount of carbon monoxide in the air after the air flows through the dehumidifier,

wherein the olfaction sensor assembly is disposed within a component of the HVAC system through which the blower of the HVAC system blows air; and

a control module configured to selectively take one or more remedial actions based on the amount of carbon monoxide in the air measured by the sensor.

2. The vehicle system of claim 1 wherein the dehumidifier includes a desiccant that decreases the humidity of the air.

3. The vehicle system of claim 1 wherein the dehumidifier includes a heat exchanger that decreases the humidity of the air.

4. The vehicle system of claim 1 wherein the dehumidifier includes a dry filter through which the air flows that decreases the humidity of the air.

5. The vehicle system of claim 4 wherein the dry filter is configured to filter droplets of moisture from the air as the air flows through the dry filter.

6. The vehicle system of claim 1 wherein the dehumidifier includes a condenser that cools the air as the air flows through the condenser and that decreases the humidity of the air.

7. The vehicle system of claim 1 wherein the dehumidifier includes a freezer that cools the air as the air flows through the freezer and that decreases the humidity of the air.

8. The vehicle system of claim 1 wherein the dehumidifier includes a heater that warms the air as the air flows through the dehumidifier and that decreases the humidity of the air.

9. The vehicle system of claim 1 wherein the dehumidifier includes a burner that decreases the humidity of the air.

10. The vehicle system of claim 1 wherein the dehumidifier includes a glass tube through which the air travels that dehydrates the air.

11. The vehicle system of claim 1 wherein the control module is configured to selectively take the one or more remedial actions when the amount of carbon monoxide in the air measured by the sensor is greater than a predetermined value.

12. The vehicle system of claim 1 wherein the control module is configured to, based on the amount of carbon monoxide in the air measured by the sensor, selectively open at least one window of the vehicle.

13. The vehicle system of claim 1 wherein the control module is configured to, based on the amount of carbon monoxide in the air measured by the sensor, selectively at least one of: turn on a blower of a heating ventilation and air conditioning system; and increase a speed of the blower.

14. The vehicle system of claim 1 wherein the blower is configured to draw air through the sensor and the dehumidifier.

15. The vehicle system of claim 1 wherein the blower is configured to blow air through the sensor and the dehumidifier.

16. The vehicle system of claim 1 wherein the dehumidifier includes a Peltier device.

17. The vehicle system of claim 1 wherein the dehumidifier includes:

a charger configured to charge water to have one of (a) a positive polarity and (b) a negative polarity; and

a plate configured to attract water and having the other one of (a) a positive polarity and (b) a negative polarity.

18. A method for a vehicle, comprising:

drawing air through an inlet of a housing of an olfaction sensor assembly using a blower disposed within the housing,

the blower separate from a second blower of a heating, ventilation, and air conditioning (HVAC) system of the vehicle,

wherein the olfaction sensor assembly is disposed within a component of the HVAC system through which the blower of the HVAC system blows air;

decreasing a humidity of the air by a dehumidifier disposed within the housing; and

directly downstream of the dehumidifier, by a sensor disposed within the housing, measuring an amount of carbon monoxide in the air after the air flows through the dehumidifier; and

selectively taking one or more remedial actions based on the amount of carbon monoxide in the air measured by the sensor.