Metal oxide sensing based on vehicle operation

Abstract

An integrated circuit for gas sensing in a vehicle includes a gas sensor with a heating element and a metal oxide (MOX) sensing element configured to provide a gas sensing signal. A microcontroller selectively controls an electrical signal applied to the heating element based on feedback from the heating element and a vehicle operating mode received from a system processor. The microcontroller adjusts heat applied to the sensing element and determines, based on signals received from the sensing element, a sensor surface condition indicative of a target gas presence within the gas sensing environment. The system enables adaptive control of the gas sensor based on different vehicle operating modes including driving, parking, idling, and charging, while providing environmental compensation without requiring co- located sensors. The integrated circuit optimizes power efficiency and sensor lifetime while maintaining detection accuracy through self-compensating temperature control and built-in self-test capabilities.

Description

METAL OXIDE SENSING BASED ON VEHICLE OPERATIONCLAIM OF PRIORITY

[0001] This application claims priority to US provisional Application Serial No. 63 / 562,546, filed on Mar. 7, 2024, which is incorporated by reference herein in its entirety, and the benefit of priority of which is claimed herein.BACKGROUND

[0002] A battery can include a battery cell or a battery module, either of which can be included in a battery pack or a battery compartment. It can be beneficial to monitor battery health, e.g., to anticipate or detect certain undesired events such as a thermal runaway accompanying battery failure. Early detection of such events can help mitigate a battery failure.BRIEF DESCRIPTION OF THE DRAWINGS

[0003] In the drawings, which are not necessarily drawn to scale, like numerals can describe similar components in different views. Like numerals having different letter suffixes can represent different instances of similar components. The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document.

[0004] FIG. 1 depicts an example of an arrangement of a gas monitoring system such as for battery monitoring.

[0005] FIG. 2A is a block diagram of an example of a system for gas monitoring.

[0006] FIG. 2B depicts an example of an integrated circuit, including a plurality of gas sensors, each including a corresponding sensing and heating element.

[0007] FIG. 2C depicts an example of a gas sensor, including a close up view of a sensing element and a heating element.

[0008] FIG. 3 is a chart showing examples of sensor responses over time during a battery event.

[0009] FIG. 4A depicts a self-test operation of an example of a gas sensor, including a sensing element being driven to heat a corresponding heating element.

[0010] FIG. 4B depicts a self-test operation of an example of a gas sensor, including a heating element being driven to heat a corresponding sensing element.

[0011] FIG. 5 is a flowchart showing an example of a decision tree for using performing gas monitoring in an enclosed environment of a vehicle.

[0012] FIG. 6 is a flowchart showing a process for controlling a gas monitoring system of a vehicle.

[0013] FIG. 7 illustrates a block diagram of a machine.DETAILED DESCRIPTION

[0014] Battery health can be monitored at the battery cell level, at a battery module level, or at a battery pack level, such as via a temperature sensor located in a battery compartment to detect a thermal runaway event. For example, certain pressure sensors can be arranged to measure a pressure changed related to a thermal event within a battery compartment. Such pressure sensors can be inadequate for detecting relatively slow pressure changes, such that pressure-based battery failure detection can be delayed to being later than desirable in the failure progression. Such a pressure sensor can also be affected by unrelated events, complicating battery health status detection. Battery health can also be monitored using a gas sensor, such as to monitor gas composition in the battery environment, such as within a battery compartment headspace. For example, an optical non-dispersive infrared (NDIR) sensor can be arranged for gas detection (e.g., detection of carbon dioxide (CO2) or carbon monoxide (CO)). However, CO2 and CO generally appear in the battery compartment headspace during a relatively late stage of battery failure, such as when thermal runaway is imminent, limiting the effectiveness of an alert or warning based on the infrared sensor. Further, use of certain optical sensors in an automotive setting can be challenging, as the sensors can be easily damaged and tend to consume significant amounts of energy.

[0015] Another approach to battery health monitoring via volatile gas sensing involves a metal oxide (MOX) sensor, which can help expedite detection of an undesired event in a battery (e.g., a thermal event, outgassing, electrolyte leaking, water damage, etc.). However, certain MOX sensors can exhibit a limited longevity after prolonged use, e.g., such as typically becoming less sensitive following repeated heating of the MOX layer. As such, certain implementations of MOX sensors can be unsuitable for automotive use, in which years of continual gas sensing are desired without needing sensor replacement. The present inventors have recognized, among other things, the benefits of an approach to monitoring battery health using a MOX sensor that is less susceptible to sensor degradation associated with certain MOX materials.

[0016] This document describes an integrated circuit (IC) comprising a gas sensor with a heating element and a metal oxide (MOX) sensing element. In an example, the microcontroller can selectively control a current or voltage applied to the heating element, such as based on at least one of feedback from the heating element itself (e.g., thermal resistive feedback) and / or based on the vehicle's operating mode. The microcontroller can control operation of the gas sensor’s heating element (heater), activating gas sensing via the MOX sensing element, according to specified vehicle scenarios. For example, the microcontroller can receive an indication of a vehicle operating mode received from a system processor (e.g., a main computer) of the vehicle. Here, while the vehicle is in a “driving” operating mode, the microcontroller can control operation of the gas sensor’s heater at a continuous high-temperature mode to promote sensitivity and rapid response of the gas sensor. Alternatively, when the vehicle is on a “parking” or “idling” operating mode, the microcontroller can regulate the gas sensor’s heater at a relatively low-temperature, such as to optimize power consumption and sensor lifetime during a timeframe where a risk of an undesired battery event is unlikely. Likewise, during a “charging” vehicle operating mode (e.g., in the case of an electric vehicle), the microcontroller can adaptively control the gas sensor based on whether alternating current (AC) or direct current (DC) charging is being used. For example, this can include regulating the gas sensor’s heating element with adifferent profile for fast charging (e.g., about 160-300kW) as compared with slower AC charging (e.g., about 10-22kW).

[0017] In an example, the microcontroller can receive thermal resistive feedback (e.g., measuring a DC resistance of the heating element) and process the feedback to help determine ambient temperature and adjust or normalize the heating control signal accordingly. For example, such a technique can help the IC perform gas sensing in the enclosed environment, despite fluctuating ambient temperatures, without requiring the microcontroller to receive additional vehicle environment temperature or humidity feedback from an auxiliary sensor.

[0018] In an example, the integrated circuit can include or be communicatively coupled with a plurality of gas sensors, e.g., enabling differential measurements such as to distinguish between internal gas events and external environmental changes. Such a multi-sensor approach can facilitate cross-validation of sensor responses and potential localization of gas events within the battery pack. For example, integration of the MOX gas sensing with the vehicle's battery management system (BMS) can involve the microcontroller receiving and processing impedance spectroscopy data from the BMS controller, such as to activate a MOX sensor based on a certain AC resistance profile or signature. Alternatively or additionally, the microcontroller can trigger gas sensing via the impedance spectroscopy sensor of the BMS, such as based on a MOX sensor surface condition indicative of a threshold amount of a target gas in the ambient headspace of the enclosed environment.

[0019] In an example, the gas sensor of the IC can include a self-testing modality, such as based on a plurality of measured conditions, such as a surface condition at each of the sensing element and the heating element. For example, the microcontroller can facilitate such a self-test by comparing heater thermal resistive feedback of the thermal element and gas sensing values of the sensing element against reference data, e.g., including inducing heat from the MOX sensing element toward the heating element for additional cross-verification. Such a self-test can further be performed, in the case ofmultiple gas sensors on a same IC, by inducing heat from a first heating element and toward a second heating element.

[0020] FIG. 1 depicts an example of an arrangement of a gas monitoring system such as for battery monitoring. The gas monitoring system 100 may be located inside or near a battery compartment 101, such as near a battery pack 102, a battery module 104, or a battery cell 105. For example, the gas monitoring system 100 can be located within a battery compartment 101, such as in the headspace 103 of the battery compartment 101. In an example, the gas monitoring system 100 can be associated with an electric or hydrogen powered vehicle, such as a car, truck, bus, motorcycles, ship, plane, train, all- terrain vehicle (ATV), tractor, e-bike, scooter, etc.

[0021] As a battery progresses through failure stages, the battery may generate volatile gases having a composition dependent on and indicative of the stage of battery failure. Certain other gas sensing solutions can be configured to detect thermal runaway but negate to address failures that occur much earlier and that are more difficult to detect (e.g., exhibiting less of a change in gas composition). For example, while thermal runaway can exhibit a change in gas composition of about A6000 parts per million (ppm), outgassing, e.g., from a first cell opening, can involve a change ranging from about A500-1000 ppm, electrolyte leaking can involve a change ranging from about A100-500 ppm, and water damage to the battery cell can exhibit a gas composition change as low as about A200 parts per billion (ppb). As discussed further below, the systems and integrated circuits described herein can include a gas sensor having a MOX material for early detection of any of a thermal runaway, outgassing, electrolyte leaking, or water damage, such as based on a sensitivity of the sensing element as it becomes activated by heat from the heating element. For example, the gas sensor can be located within the headspace of a battery compartment, and selectively activated to monitor for early signs or signatures indicative of a mechanical, thermal, or electrical battery failure.

[0022] For example, mechanical battery cell failure can be associated with defects arising during manufacturing, or indirectly during a vehicle accident via impact to the vehicle underbody. Thermal failure can occur duringmalfunction of a thermal management system or can be exacerbated by an external factor, e.g., ambient temperature or a manufacturing defect. Electrical failure, such as overload, can be caused by overcharge or based on out-of- specification operation of the battery or the vehicle. Each of these failures can lead to mixing of internal battery components with the ambient air within the battery pack. Earlier detection of a potential catastrophic failure can help a battery management or other system to react to the detected event, such as to start responding with a corrective action or to notify a driver or a passenger of the potential failure. Corrective action can include disconnecting or discharging an affected battery compartment, increasing cooling to counteract heating that may be leading to a battery event, or limiting demand on the battery, one or more of which may help to halt or reverse the battery failure.

[0023] Certain gas monitoring systems can be used to detect one or more volatile gases that may indicate imminent failure of a battery in the headspace of a battery compartment. A battery at an early stage of failure, may primarily produce, in the case of electrolyte leakage, gases such as Ethylene Carbonate (EC), Dimethyl Carbonate (DMC), Diethyl Carbonate (DEC), and Ethyl Methyl Carbonate (EMC). In the case of electrolysis of water, a battery may primarily produce gases such as EE and O2. A battery at a later stage of battery failure, the so called “first venting”, may primarily produce gases such as DEC, DMC, EMC, and H2O, as well as producing lesser amounts of gases such as CO, CO2, EC, and C4H10. A battery at a stage of battery failure where combustion is fairly immediately imminent, the so called “thermal runaway”, may primarily produce gases such as CO2, CO, C2H4, and H2 as well as lesser portions of gases such as C2H2, C2H6, CH4, DEC, DMC, EMC, H2O, C4H10, and O2. A battery that has combusted may primarily produce gases such as CO, CO2, and HF.

[0024] FIG. 2A and FIG. 2B are each block diagrams of an example of portions of a system for gas monitoring. In an example, the gas monitoring system 100 can include an integrated circuit 202 including a microcontroller 212 and a gas sensor 228, the gas sensor 228 including at least one heating element 204 and at least one sensing element 210. The integrated circuit 202 can be disposed within a gas sensing environment 220, such as a battery compartment of a vehicle. In an example, the gas monitoring system 100 caninclude or be communicatively coupled with any of a vehicle system processor 224, a battery management system (BMS) controller 230, a cell monitor 231, or one or more auxiliary sensors 226. Herein, “microcontroller 212” generally refers to a microcontroller unit (MCU) located on the integrated circuit 202, it can be understood that other components (e.g., the BMS controller 230, the cell monitor, the vehicle system processor 224, etc.) may have their own microcontrollers. In an example, certain operations described herein can be performed by the microcontroller 212 can alternatively be performed on a microcontroller of the BMS controller 230.

[0025] The sensing element 210 of the gas sensor 228 can be sensitive to changes in gaseous environments and its electrical properties change with the presence of different gas concentrations. The integrated circuit 202 can include a converter (e.g., a Howland current pump) to convert the signal from the sensing element into a voltage or current to be interpreted by the microcontroller 212. The integrated circuit 202 can also include a physical layer (PHY) chip arranged for interconnection to other systems or networks inside the battery pack (e.g., the BMS controller 230). The integrated circuit 202 can be capable of processing the data received from the gas sensor 228 and provide a sensor response over the digital or analog interface indicating whether the gaseous environment of the battery pack is presently safe. Here, no additional processing is required from any other system in the vehicle, such as to interpret the raw data response from the gas sensor 228. Alternatively or additionally, processing of the raw data response from the gas sensor 228 can be performed on other remote systems, e.g., connected via the PHY chip.

[0026] In an example, the heating element 204 can be arranged on the integrated circuit 202 proximate to the sensing element 210, such that when an electrical signal (e.g., a voltage or current) is applied to the heating element 204 by the microcontroller 212, the sensing element 210 becomes activated. As shown in FIG. 2B, the integrated circuit 202 can include a plurality of heating elements 204, each corresponding with one of a plurality of sensing elements 210. Alternatively, an individual heating element 204 can serve multiple of the sensing elements 210, such that the relationship between the heating plurality of heating elements 204 and the plurality of sensing elements 210 is not strictly 1-to-l. Over a lifetime of the gas sensor 228, an amount ofactive “on” time of the heating element 204 at relatively high temperatures (e.g., >200°C) the main contributor to progressive degradation of sensing element 210. In an example, the microcontroller 212 can regulate the voltage or current applied to the heating element 204 depending on a scenario or operating mode the car is presently in, such as fast charging, slow charging, parking, driving, idling, etc. In an example, in information about the car’s status (e.g., operating mode, ambient temperature about the vehicle, a relative humidity about the vehicle, an indication of a collision, etc.) can be transmitted by the vehicle system processor 224 or the BMS controller 230 and received by the microcontroller 212 as an input. Such status information about the car can be used via the microcontroller 212 to improve a power efficiency of the gas sensor, promoting sensor longevity and improving the sensor sensitivity over time due to adaptive control of the heating element 204.

[0027] For example, where the microcontroller 212 receives an input that the vehicle is in a “driving" mode, it can be assumed or inferred that an ambient environment about the vehicle may be constantly changing (e.g., the vehicle may be going through a tunnel, a car wash, a traffic jam, a city versus a country side, etc.). Therefore, control of the voltage or current applied to the heating element 204 such that the heater control is operated in a more continuous mode at higher temperatures, e.g., to promote full sensitivity of the MOX material 214 and achieve the most rapid gas sensor response. Where the microcontroller 212 receives an input that the vehicle is in a “parked” mode, it can be assumed or inferred that the vehicle is in a relatively stable environment (e.g., compared to that of the “driving” mode). As such, the microcontroller 212 can reduce an amount of voltage or current applied at the heating element 204, e.g., reducing a sensitivity of sensing via the gas sensor, while the vehicle remains parked. Where the microcontroller 212 receives an input that the vehicle is in an “idling” mode (e.g., vehicle functionality between the “parked” mode and the “driving”, such as sitting idle at a traffic light or otherwise experiencing a temporary stop in motion), it can be assumed that environmental conditions are similar to that of the “parked” mode and the microcontroller can control the voltage or current applied at the heating element 204 accordingly. Where the microcontroller 212 receives an input that the vehicle is in a “charging” mode, accurate, constant sensing of the gassensor 228 can be of high importance. For example, where the microcontroller 212 derives that the vehicle is receiving direct current (DC) during charging, it can be assumed or inferred that, over a relatively short charging period (e.g., about 40 minutes), a relatively high amount of energy provided to the battery cells (typically from about 160 Kilowatts (kW) to about 300kW). As such, the microcontroller 212 can facilitate maximum or near-maximum voltage or current applied to the heating element 204, such as to facilitate MOX sensing at or near a highest sensitivity. Alternatively, where the microcontroller 212 determines that the vehicle is receiving alternating current (AC) during charging, it can be assumed or inferred that, over a relatively long charging period (e.g., about 6 to 8 hours), a relatively low amount of energy provided to the battery cells (typically from about 160 Kilowatts (kW) to about 300kW). Since less energy is provided to the battery cells compared during AC charging, it can be assumed or inferred that a sensing sensitivity can be relaxed as compared with the sensitivity during DC charging, yet remain more sensitive (e.g., and consuming more energy) than sensing during the “parked” mode. As such, the microcontroller 212 can facilitate maximum or nearmaximum voltage or current applied to the heating element 204, such as to facilitate MOX sensing at or near a highest sensitivity.

[0028] While the microcontroller 212 is regulating the heating element 204 at or near a highest intensity, the microcontroller 212 can apply, e.g., 1-5 milliamperes (mA) to cause a temperature at the heating element 204 to be between 200°C and 300°C, promoting a high or maximum sensing element 210 response. In certain scenarios (e.g., certain vehicle operating modes), the microcontroller 212 can modulate a duty cycle of the heating element 204 while the highest intensity parameters are delivered, such as to achieve certain benefits of high-temperature MOX sensing while preserving at least some longevity of the sensing element 210. While the microcontroller 212 is regulating the heating element 204 at or near a standard intensity, the microcontroller 212 can apply <1 mA to cause a temperature at the heating element 204 to be between 60°C and 100°C, promoting relatively rapid “on- time”, cleaning of sensor from humidity, and to mitigate thermal stress. While the microcontroller 212 is regulating the heating element 204 at or near a minimum intensity at which a meaningful response from the sensing elements210 can be received. Such a heating profile can facilitate that less MOX material 214 of the sensing element 210 is exposed to an actual activation temperature from the heating element 204, promoting a longevity of the MOX material 214.

[0029] FIG. 2C depicts an example of a gas sensor, including a close-up view of a sensing element and a heating element. In an example, the sensing element 210 and the heating element 204 can be formed as opposing traces on a chip, such as the sensing element 210 being an interdigitated electrode. Here, the heating element 204 can be formed as a relatively thicker trace, disposed around the interdigitated electrode (as depicted in FIG. 2C) or formed beneath the interdigitated electrode on the integrated circuit. Here the MOX material 214 can be a semiconductive material disposed atop or in between the traces of the sensing element 210 and the traces of the heating element 204. As the heating element 204 is heated up, the MOX material 214 can be activated to detect changes in conductivity influenced by an amount of oxygen removed from the sensor surface by the target gas, such that the sensing element 210 receives a sensor surface condition indicative of a presence of a target gas at or near the chip or a gas headspace about the chip.

[0030] In an example, to help facilitate precise and repeatable sensor response, a temperature of the heater can be controlled (e.g., in a closed-loop fashion) and compensated against environmental conditions (e.g., conditions of the ambient environment about the vehicle). To facilitate the temperature compensation, the microcontroller 212 can monitor at least one thermal resistive characteristic (e.g., a DC resistance) of the heating element 204 to help identify the actual ambient temperature, such as by performing a low current resistive measurement on the heating element 204. Based on the ambient temperature, the change in temperature needed to achieve the target temperature can be indirectly adjusted, e.g., by adapting the voltage or current to the heating element 204. By tracking the voltage or current applied to the heating element 204, a target temperature can be regulated, such as independently from the surrounding external ambient environment about the vehicle. Such a technique for temperature compensation can also help protect the sensing element 210 from overheating in an event where the external ambient environment is at above average temperatures.

[0031] In an example, the MOX material 214 can be sensitive to ambient temperature changes and humidity. Here, the microcontroller 212 can facilitate compensating a gas sensor 228 response, such that the sensing element 210 is actually triggered by target gas. The heater heating element 204 can be indirectly environmentally compensated without requiring actual environmental sensors co-located therewith. In an example, environmental data can be received via the microcontroller 212 and from the vehicle’s network (e.g., from the vehicle system processor 224). As such, the microcontroller 212 can compensate (e.g., slightly attenuate, adjust, or offset a response curve) without requiring a dedicated environmental sensor colocated with the gas sensor 228.

[0032] In an example, data from other systems can be pulled and processed on the microcontroller 212 or processed in the BMS controller 230 (e.g., via the BMS) or the cell monitor 231. In an example, the gas monitoring system 100 can be integrated into a battery pack communication framework, such as by supporting the same physical layer and protocol or integration on the existing PCB design of the battery modules. In an example, the cell monitor 231 can perform or receive measurements of impedance spectroscopy in each individual battery cell of the battery pack and process the impedance spectroscopy date concurrently with the response from the sensing element 210. Such impedance spectroscopy can be leveraged to detect battery cell failures, e.g., even before an actual outgassing event occurs. For example, the microcontroller 212 can receive impedance spectroscopy data from the BMS controller 230. Here, the impedance spectroscopy data can be indicative of an alternating current (AC) resistance over time of an individual battery cell in the enclosed gas sensing environment. The microcontroller 212 can then commence applying the voltage or current to the heating element 204 of the gas sensor 228, such as based on the AC resistance over time (e.g., concurrently at multiple frequencies, such as at or near about 100 hertz (hz), at or near about 1000 hz, at or near about 10,000 hz, etc.) Such a multifrequency or multi-band profile can exhibit a specified impedance signature indicative of a battery failure (e.g., determined based on comparison with a lookup table or other exemplary battery failure signature characteristics. Alternatively or additionally, the microcontroller 212 can trigger auxiliary gassensing of an individual battery cell, e.g., via an impedance spectroscopy sensor in the BMS, based on the sensor surface condition indicative of a specified amount of a target gas. Here, the impedance spectroscopy can be performed to help identify a specific cell that is responsible for the battery failure.

[0033] FIG. 3 is a chart showing examples of sensor responses over time during a battery event. In an example, as depicted in FIG. 2B, an integrated circuit can include a plurality of MOX gas sensors, such as having at least two sensing elements (e.g., each corresponding to a respective heating element). The integrated circuit can concurrently monitor a plurality of gas sensors to determine whether their respective sensor responses 304, 306 (e.g., in mA over time) resemble a typical sensor response during a thermal event. As shown in FIG. 3, during a thermal runaway, gas concentration becomes significantly higher than an initial venting concentration, until exhibiting a peak and a flatline.

[0034] In an example, an impedance spectroscopy response 302 from one or more impedance spectroscopy sensors in a BMS can provide a slightly advanced indication of a thermal runaway event. Here, the plurality of MOX gas sensors can be activated based on this initial response 302 from the impedance spectroscopy sensor, and the sensor responses 304, 306 can be monitored or compared with a references to determine whether they exhibit signatures indicative of a thermal runaway event.

[0035] FIG. 4A and FIG. 5B depict a self-test operation of an example of a gas sensor. In an example, a microcontroller of an integrated circuit can facilitate a “self-test”, such as based on an operation to interpret the sensor surface condition. For example, such a self-test can be achieved by comparing the heater thermal resistances and sensing element current values against a look up table. As depicted in FIG. 4A, typical operation of the gas sensor involves inducing heat from the heating element 204 toward the sensing element 210. As shown in FIG. 4B, the microcontroller can also facilitate inducing a relatively small amount of heat from the sensing element 210 toward the heating element 204. In this way the heating element and the sensing element can be counterchecked, such as to test functionality of theheating and sensing elements, as well as the integrity of the MOX material of the gas sensor.

[0036] FIG. 5 is a flowchart showing an example of a decision tree for using performing gas monitoring within an enclosed environment of a vehicle. In an example, the process 500 can be performed by the system 100 of FIG. 2A, such as operations initiated via the microcontroller 212 on the integrated circuit 202.

[0037] At 504, an electrical signal, e.g., a voltage or a current, can be applied to each of the sensing element and the heating element. In an example, the electrical signal can be a linear voltage (i.e., a stable, regulated output voltage using a linear, non-switching technique).

[0038] At 506, absent heating via the heating element and at an ambient temperature, sensing via the sensing element can be performed. Here, the electrical signal applied to at least the sensing element can be constantly polled or monitored (e.g., feedback received in the millisecond (ms) range), such that the electrical signal can remain regulated and to mitigate fluctuations during sensing.

[0039] At 508, heat can be applied via the heating element while sensing via the sensing element is performed. Here, a relatively low amount of heat (e.g., <200°C) can be applied via the heating element, resulting in relatively low sensitivity gas sensing.

[0040] At 510, a microcontroller can determine, based on sensor feedback from one or both of the sensing element and the heating element, whether a gas change is detected in the sensing environment. Concurrently, at 526, a vehicle operation mode can be received via the microcontroller and from a system processor of the vehicle (e.g., a main computer of the vehicle). At 512, where a gas change is not determined at 510, the sensing data can be stored (e.g., on memory of the integrated circuit) and the process can return to operation 506. Where a gas change is detected, any combination of a series of operations (514, 516, and 522) can be performed in any order to determine whether the change in gas corresponds with an indication of an undesired battery cell event.

[0041] At 514, a low temperature, high sensitivity measurement can be taken by the gas sensor, e.g., based on a relatively low amount of heat (e.g., <200°C) applied via the heating element. At 518, an environmental properties measurement can be taken, e.g., based on thermal resistive feedback from the heating element. In an example, based on the measurements at 514 and 518, the operation 516 can be commenced.

[0042] At 516, a relatively high temperature, high sensitivity measurement can be taken to determine a change in concentration of a target gas. For example, such a high sensitivity measurement can be based on a relatively high amount of heat (e.g., >200°C) applied via the heating element.

[0043] At 520, based on any of the measurements at 514, 516, and 518, the microcontroller can determine whether the indication of the gas change at 510 corresponds with an environmental change (e.g., based on the environmental properties measurement at operation 518). If the microcontroller determines that the indication of the gas change at 510 does correspond with an environmental change, the data can be stored and the process can return to operation 506 and, e.g., repeat subsequent steps.

[0044] At 522, if the microcontroller determines that the indication of the gas change at 510 does not correspond with an environmental change, the measurements from the sensing element can be compared with a threshold lookup table corresponding with the target gas.

[0045] At 524, if the measurements from the sensing element exceed a specified threshold from the threshold lookup table, an alert can be triggered. For example, the alert can be transmitted to the system processor of the vehicle to notify a passenger of the vehicle to evacuate the vehicle. Further, the alert can be transmitted to the BMS controller or the cell monitor, e.g., to trigger initiation of a battery failure mitigation process.

[0046] FIG. 6 is a flowchart showing a process for controlling a gas monitoring system of a vehicle. In an example, the process 600 can be performed by the system 100 of FIG. 2 A, such as operations initiated via the microcontroller 212 on the integrated circuit 202.

[0047] At 602, a vehicle operating mode can be received from a system processor of the vehicle. This operating mode may include states such asdriving, parking, charging (AC or DC), or idling. In an example, temperature data can also be received from auxiliary sensors about the vehicle's environment. These auxiliary sensors may include battery cell sensors or vehicle ambient environment sensors, providing additional context for optimizing gas sensor operation.

[0048] At 604, the process 600 can involve controlling an electrical signal applied to a heating element based one of several multiple inputs, e.g., feedback from the heating element itself (thermal resistive feedback / DC resistance), the received vehicle operating mode, or temperature data from auxiliary sensors. In an example, the process 600 can involve normalizing heat applied to the sensing element via the heating element based on the thermal resistive feedback to offset ambient temperature of the vehicle. Such a normalization step can help facilitate accurate sensor response across varying environmental conditions.

[0049] At 606, a sensor surface condition, indicative of a presence of a target gas within a gas sensing environment, can be determined, e.g., based on a gas sensing signal received from a metal oxide (MOX) sensing element. In an example, such a determination involves analyzing sensor responses to detect a change in a target gas presence greater than 1000 parts per million (ppm). In an example, the process 600 can involve continuously monitoring and adjusting the heating element control based on real-time feedback and multiple data sources, such as to facilitate requisite sensor performance while maintaining power efficiency appropriate to the current vehicle operating mode.

[0050] FIG. 7 illustrates generally an example of a block diagram of a machine 701 upon which any one or more of the techniques (e.g., methodologies) discussed herein may perform in accordance with some examples. In alternative embodiments, the machine 701 may operate as a standalone device or may be connected (e.g., networked) to other machines. In a networked deployment, the machine 701 may operate in the capacity of a server machine, a client machine, or both in server-client network environments. In an example, the machine 701 may act as a peer machine in peer-to-peer (P2P) (or other distributed) network environment. The machine701 may be a personal computer (PC), a tablet PC, a set-top box (STB), a personal digital assistant (PDA), a mobile telephone, a web appliance, a network router, switch or bridge, or any machine capable of executing instructions (sequential or otherwise) that specify actions to be taken by that machine. Further, while only a single machine is illustrated, the term “machine” shall also be taken to include any collection of machines that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein, such as cloud computing, software as a service (SaaS), other computer cluster configurations.

[0051] Examples, as described herein, may include, or may operate on, logic or a number of components, modules, or mechanisms. Modules are tangible entities (e.g., hardware) capable of performing specified operations when operating. A module includes hardware. In an example, the hardware may be specifically configured to carry out a specific operation (e.g., hardwired). In an example, the hardware may include configurable execution units (e.g., transistors, circuits, etc.) and a computer readable medium containing instructions, where the instructions configure the execution units to carry out a specific operation when in operation. The configuring may occur under the direction of the executions units or a loading mechanism. Accordingly, the execution units are communicatively coupled to the computer readable medium when the device is operating. In this example, the execution units may be a member of more than one module. For example, under operation, the execution units may be configured by a first set of instructions to implement a first module at one point in time and reconfigured by a second set of instructions to implement a second module.

[0052] Machine (e.g., computer system) 701 may include a hardware processor 702 (e.g., a central processing unit (CPU), a graphics processing unit (GPU), a hardware processor core, or any combination thereof), a main memory 703 and a static memory 704, some or all of which may communicate with each other via an interlink (e.g., bus) 705. The machine 701 may further include a display unit 706, an alphanumeric input device 707 (e.g., a keyboard), and a user interface (UI) navigation device 708 (e.g., a mouse). In an example, the display unit 706, alphanumeric input device 707 and uinavigation device 708 may be a touch screen display. The machine 701 may additionally include a storage device (e.g., drive unit) 709, a signal generation device 710 (e.g., a speaker), a network interface device 711, and one or more sensors 712, such as a global positioning system (GPS) sensor, compass, accelerometer, or other sensor. The machine 701 may include an output controller 716, such as a serial (e.g., universal serial bus (USB), parallel, or other wired or wireless (e.g., infrared (IR), near field communication (NFC), etc.) connection to communicate or control one or more peripheral devices (e.g., a printer, card reader, etc.).

[0053] The storage device 709 may include a machine readable medium 713 that is non-transitory on which is stored one or more sets of data structures or instructions 714 (e.g., software) embodying or utilized by any one or more of the techniques or functions described herein. The instructions 714 may also reside, completely or at least partially, within the main memory 703, within static memory 704, or within the hardware processor 702 during execution thereof by the machine 701. In an example, one or any combination of the hardware processor 702, the main memory 703, the static memory 704, or the storage device 709 may constitute machine readable media.

[0054] While the machine readable medium 713 is illustrated as a single medium, the term “machine readable medium” may include a single medium or multiple media (e.g., a centralized or distributed database, or associated caches and servers) configured to store the one or more instructions 714.

[0055] The term “machine readable medium” may include any medium that is capable of storing, encoding, or carrying instructions for execution by the machine 701 and that cause the machine 701 to perform any one or more of the techniques of the present disclosure, or that is capable of storing, encoding or carrying data structures used by or associated with such instructions. Nonlimiting machine-readable medium examples may include solid-state memories, and optical and magnetic media. Specific examples of machine- readable media may include: non-volatile memory, such as semiconductor memory devices (e.g., Electrically Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM)) and flash memory devices; magnetic disks, such as internal harddisks and removable disks; magneto-optical disks; and CD-ROM and DVD- ROM disks.

[0056] The instructions 714 may further be transmitted or received over a communications network 715 using a transmission medium via the network interface device 711 utilizing any one of a number of transfer protocols (e.g., frame relay, internet protocol (IP), transmission control protocol (TCP), user datagram protocol (UDP), hypertext transfer protocol (HTTP), etc.). Example communication networks may include a local area network (LAN), a wide area network (WAN), a packet data network (e.g., the Internet), mobile telephone networks (e.g., cellular networks), Plain Old Telephone (POTS) networks, and wireless data networks (e.g., Institute of Electrical and Electronics Engineers (IEEE) 702.11 family of standards known as Wi-Fi®, IEEE 702.16 family of standards known as WiMax®), IEEE 702.15.4 family of standards, peer-to- peer (P2P) networks, among others. In an example, the network interface device 711 may include one or more physical jacks (e.g., Ethernet, coaxial, or phone jacks) or one or more antennas to connect to the communications network 715. In an example, the network interface device 711 may include a plurality of antennas to wirelessly communicate using at least one of singleinput multiple-output (SIMO), multiple-input multiple-output (MIMO), or multiple-input single-output (MISO) techniques. The term “transmission medium” shall be taken to include any intangible medium that is capable of storing, encoding or carrying instructions for execution by the machine 701, and includes digital or analog communications signals or other intangible medium to facilitate communication of such software.

[0057] The above Detailed Description can include references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the invention can be practiced. These embodiments are also referred to herein as “examples.” Such examples can include elements in addition to those shown or described. However, the present inventors also contemplate examples in which only those elements shown or described are provided. Moreover, the present inventors also contemplate examples using any combination or permutation of those elements shown or described (or one or more aspects thereof), either with respect to a particular example (or one or more aspectsthereof), or with respect to other examples (or one or more aspects thereof) shown or described herein.

[0058] In the event of inconsistent usages between this document and any documents so incorporated by reference, the usage in this document controls. In this document, the terms “including” and “in which” are used as the plain- English equivalents of the respective terms “comprising” and “wherein.” Also, in the following claims, the terms “including” and “comprising” are open- ended, that is, a system, device, article, composition, formulation, or process that can include elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim.

[0059] In this document, the terms “a” or “an” are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of “at least one” or “one or more.” In this document, the term “or” is used to refer to a nonexclusive or, such that “A or B” can include “A but not B,” “B but not A,” and “A and B,” unless otherwise indicated. In this document, the terms “including” and “in which” are used as the plain- English equivalents of the respective terms “comprising” and “wherein.” Also, in the following claims, the terms “including” and “comprising” are open- ended, that is, a system, device, article, composition, formulation, or process that can include elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects.

[0060] The above description is intended to be illustrative, and not restrictive. For example, the above-described examples (or one or more aspects thereof) can be used in combination with each other. Other embodiments can be used, such as by one of ordinary skill in the art upon reviewing the above description. The Abstract is provided to comply with 37 C.F.R. § 1.72(b), to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features can be grouped together to streamlinethe disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter can lie in less than all features of a particular disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description as examples or embodiments, with each claim standing on its own as a separate embodiment, and it is contemplated that such embodiments can be combined with each other in various combinations or permutations. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

CLAIMSWhat is claimed is:

1. An integrated circuit for use in an enclosed gas sensing environment associated with a vehicle, the integrated circuit comprising: a gas sensor including a heating element and a sensing element including a metal oxide (MOX) sensing material, the gas sensor configured to provide a gas sensing signal; and a microcontroller configured to: selectively control an electrical signal applied to a heating element of the gas sensor, including adjusting a heat applied via the heating element to a sensing element of the gas sensor, based on feedback from the heating element and a vehicle operating mode received from a system processor of the vehicle; and determine, based on signal received from the sensing element of the gas sensor, a sensor surface condition indicative of a presence of a target gas within the gas sensing environment.

2. The integrated circuit of claim 1, wherein the microcontroller is configured to selectively control the electrical signal applied to the heating element of the gas sensor based on a temperature of an environment about the vehicle received from an auxiliary sensor.

3. The integrated circuit of claim 2, wherein the auxiliary sensor is at least one of a battery cell sensor or a vehicle ambient environment sensor.

4. The integrated circuit of any preceding claim, wherein the feedback from the heating element is thermal resistive feedback.

5. The integrated circuit of claim 4, wherein the microcontroller is configured to normalize a heat applied, to the sensing element via the heating element, based on the thermal resistive feedback to offset an ambient temperature associated with the vehicle.

6. The integrated circuit of any preceding claim, wherein the microcontroller is configured to determine, based on the sensor surface condition, a presence of the target gas greater than 1000 parts per million (ppm).

7. The integrated circuit of claim 6, wherein the microcontroller is configured to trigger an alert indicating at least one of a thermal event within the enclosed environment, electrolyte leaking out of the enclosed environment, outgassing from the enclosed environment, or a presence of water in the enclosed environment.

8. The integrated circuit of any preceding claim, configured for applying an electrical signal to the sensing element and receiving a thermal conductance signal from the heating element of the gas sensor.

9. The integrated circuit of any preceding claim, wherein the controlling the electrical signal at the heating element is performed based on the vehicle operating mode and the signal from the sensing element of the gas sensor, without needing sensor data from an additional auxiliary environment sensor.

10. The integrated circuit of claim 9, wherein the vehicle operating mode includes at least one of traveling, idling, charging, or parked.

11. The integrated circuit of claim 10, wherein adjusting the electrical signal applied to the heating element is based on whether the vehicle operating mode includes vehicle charging from an alternating current (AC) source or from a direct current (DC) source.

12. The integrated circuit of any preceding claim, wherein the microcontroller is configured to: receive impedance spectroscopy data from a battery management system (BMS) controller, the impedance spectroscopy data indicative of an alternating current (AC) resistance over time of an individual battery cell in the enclosed gas sensing environment; andcommencing applying the electrical signal to the heating element of the gas sensor, based on the AC resistance over time exhibiting a specified impedance signature indicative of a battery failure.

13. The integrated circuit of any preceding claim, wherein the microcontroller is configured to: trigger auxiliary gas sensing of an individual battery cell, via an impedance spectroscopy sensor in a battery management system (BMS), based on the sensor surface condition indicative of a specified amount of a target gas.

14. A computer implemented method for controlling a gas monitoring system of a vehicle, the method comprising: receiving, from a system processor of the vehicle, a vehicle operating mode; monitoring, via a gas sensor providing a gas sensing signal, a presence of a target gas in an enclosed gas sensing environment within the vehicle, including controlling an electrical signal applied to a heating element of the gas sensor based on feedback from the heating element and the vehicle operating mode received from the system processor of the vehicle; and determining, based on the gas sensing signal received from a metal oxide (MOX) sensing element of the gas sensor, a sensor surface condition indicative of a presence of the target gas within the gas sensing environment.

15. The method of claim 14, comprising: receiving, from an auxiliary sensor, a temperature of an environment about the vehicle; wherein the controlling the electrical signal applied to the heating element of the gas sensor based on the received temperature of an environment about the vehicle.

16. The method of claim 15, wherein the auxiliary sensor is at least one of a battery cell sensor or a vehicle ambient environment sensor.

17. The method of any of claims 14 to 16, wherein the feedback from the heating element is thermal resistive feedback.

18. The method of claim 17, comprising normalizing heat applied, to the sensing element via the heating element, based on the thermal resistive feedback to offset an ambient temperature of the vehicle.

19. The method of any of claims 14 to 18, wherein sensor surface condition is indicative of a presence of the target gas greater than 1000 parts per million (ppm).

20. The method of claim 19, comprising triggering an alert indicating at least one of a thermal event within the enclosed environment, electrolyte leaking out of the enclosed environment, outgassing from the enclosed environment, or a presence of water in the enclosed environment.

21. The method of any of claims 14 to 20, comprising applying an electrical signal to the sensing element and receiving a thermal conductance signal from the heating element of the gas sensor.

22. The method of any of claims 14 to 21, wherein the controlling the electrical signal at the heating element is performed based on the vehicle operating mode and the signal from the sensing element of the gas sensor, without needing sensor data from an additional auxiliary environment sensor.

23. The method of claim 22, wherein the vehicle operating mode includes at least one of traveling, idling, charging, or parked.

24. The method of claim 23, wherein adjusting the electrical signal applied to the heating element based on whether the vehicle operating mode includes vehicle charging from an alternating current (AC) source or from a direct current (DC) source.

25. The method of any of claims 14 to 24, comprising: receiving impedance spectroscopy data from a battery management system (BMS) controller, the impedance spectroscopy data indicative of an alternating current (AC) resistance over time of an individual battery cell in the enclosed gas sensing environment; andcommencing applying the electrical signal to the heating element of the gas sensor, based on the AC resistance over time exhibiting a specified impedance signature indicative of a battery failure.

26. The method of any of claims 14 to 25, comprising triggering auxiliary gas sensing of an individual battery cell, via an impedance spectroscopy sensor in a battery management system (BMS), based on the sensor surface condition indicative of a specified amount of a target gas.

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