Quick wake-up oxygen sensor
By monitoring pre-start notifications and heating the oxygen sensor sensing element through the vehicle controller, the problem of oxygen sensor condensation damage was solved, enabling rapid closed-loop fuel control of the internal combustion engine and improving emissions and combustion stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GM GLOBAL TECHNOLOGY OPERATIONS LLC
- Filing Date
- 2025-02-07
- Publication Date
- 2026-06-12
Smart Images
Figure CN122190876A_ABST
Abstract
Description
Technical Field
[0001] This topic relates to vehicles, and more specifically to systems for activating oxygen sensors. Background Technology
[0002] Vehicles, including those with internal combustion engines (ICE), utilize oxygen (O2) sensors to enable sensor-based closed-loop fuel control. Closed-loop fuel control allows for an ideal trade-off between various emission standards while minimizing emissions from ICE due to tolerance build-ups, vehicle aging, test parameters, and other variations.
[0003] However, when the O2 sensor is engaged and the sensing element is too cold, condensation may occur, causing water droplets to deposit on the sensing element. Operating the sensing element while water droplets are present can lead to breakage, damaging the O2 sensor and potentially requiring replacement. Pre-treating the O2 sensor by using a heater to regulate its temperature allows it to operate without condensation.
[0004] In the existing system, pre-conditioning results in a delay of several seconds after ICE startup and before the O2 sensor can operate. During this period, fuel control operates in an open-loop manner, and tailpipe emissions are less controllable.
[0005] The goal is to minimize or eliminate open-loop fuel control operations, thereby improving tailpipe emission control. Summary of the Invention
[0006] In one exemplary embodiment, the vehicle includes at least a first oxygen sensor having a sensing element and a heating element. The vehicle also includes an energy storage system, an internal combustion engine, and a controller controllably coupled to the energy storage system, coupled to the internal combustion engine, and communicating with the at least first oxygen sensor. The controller includes an oxygen sensor wake-up module configured to respond to a received pre-start notification indicating that the internal combustion engine is about to start by comparing the temperature of the sensing element of the first oxygen sensor with a target temperature, heating the sensing element until it reaches at least the target temperature when the heating element is below the target temperature, and starting the internal combustion engine after heating the sensing element.
[0007] In addition to one or more features described herein, the at least first oxygen sensor includes a second oxygen sensor, and wherein the oxygen sensor wake-up module controls the first oxygen sensor and the second oxygen sensor.
[0008] In addition to one or more features described herein, the vehicle is a hybrid electric vehicle, and the pre-start notification is when the state of charge of the energy storage system drops below the energy storage system's charge maintenance limit.
[0009] In addition to one or more features described in this article, pre-launch notification is the predetermined proximity of a token object to a vehicle.
[0010] In addition to one or more features described herein, a pre-start notification is an operator's action on at least one vehicle system.
[0011] In addition to one or more features described herein, starting the internal combustion engine after heating the sensing element to the threshold temperature includes starting the internal combustion engine under closed-loop fuel control.
[0012] In addition to one or more features described herein, heating the sensing element until it reaches at least the target temperature when the heating element is below the target temperature includes supplying power to the heater according to a duty cycle, wherein the duty cycle depends on the difference between the temperature of the sensing element and the target temperature.
[0013] In addition to one or more features described herein, the target temperature is the dew point of the sensing element.
[0014] In addition to one or more features described herein, the temperature of the sensing element of the first oxygen sensor is continuously compared with a target temperature until the internal combustion engine is started, and the duty cycle is adjusted based on the current difference between the temperature of the sensing element and the target temperature.
[0015] In another exemplary embodiment, the vehicle controller includes a processor and a non-transitory memory. The non-transitory memory stores an oxygen sensor wake-up module. The oxygen sensor wake-up module is configured to: respond to a received pre-start notification indicating that the internal combustion engine is about to start by comparing the temperature of a sensing element of a first oxygen sensor with a target temperature, and heating the sensing element until it reaches at least the target temperature when the sensing element is below the target temperature, and starting the internal combustion engine after heating the sensing element.
[0016] In addition to one or more features described herein, starting the internal combustion engine after heating the sensing element includes starting the internal combustion engine in a closed-loop fuel control mode.
[0017] In yet another exemplary embodiment, the method for waking up an oxygen sensor in a vehicle includes: receiving a pre-start notification indicating that an internal combustion engine is about to start, comparing the temperature of a sensing element of a first oxygen sensor with a target temperature, and in response to the pre-start notification, heating the sensing element until the sensing element reaches at least the target temperature when the heating element is below the target temperature, and starting the internal combustion engine after heating the sensing element.
[0018] In addition to one or more features described herein, the method further includes comparing the temperature of the sensing element of the second oxygen sensor with a target temperature, and in response to the pre-start notification, heating the sensing element of the second oxygen sensor until the sensing element of the second oxygen sensor reaches at least the target temperature when the sensing element of the second oxygen sensor is below the target temperature.
[0019] In addition to one or more features described herein, the pre-start notification is when the state of charge of the energy storage unit drops below the energy storage unit's charge maintenance limit, and wherein the first oxygen sensor is an oxygen sensor for a hybrid electric vehicle.
[0020] In addition to one or more features described in this article, pre-launch notification is the predetermined proximity of a token object to a vehicle.
[0021] In addition to one or more features described herein, a pre-start notification is an operator's action on at least one vehicle system.
[0022] In addition to one or more features described herein, starting an internal combustion engine after a heating sensing element includes starting an internal combustion engine under closed-loop fuel control.
[0023] In addition to one or more features described herein, heating the sensing element until the heating element reaches at least the target temperature when the heating element is below the target temperature includes supplying power to the heating element according to a duty cycle, wherein the duty cycle depends on the difference between the temperature of the sensing element and the target temperature.
[0024] In addition to one or more features described herein, the target temperature is the dew point of the sensing element.
[0025] In addition to one or more features described herein, the temperature of the sensing element of the first oxygen sensor is continuously compared with a target temperature until the internal combustion engine is started, and the duty cycle is adjusted based on the current difference between the temperature of the sensing element and the target temperature.
[0026] The above-described features and advantages, as well as other features and advantages, of this disclosure will become apparent when taken in conjunction with the accompanying drawings and the following detailed description. Attached Figure Description
[0027] Other features, advantages, and details appear by way of example only in the following detailed description, which is described in detail with reference to the accompanying drawings, wherein:
[0028] Figure 1 This is a schematic diagram of a hybrid electric vehicle;
[0029] Figure 2 It is used for preprocessing Figure 1 The process of the vehicle's oxygen (O2) sensor; and
[0030] Figure 3 This is a graph showing the relationship between the O2 sensor temperature and the heater duty cycle. Detailed Implementation
[0031] The following description is exemplary in nature only and is not intended to limit this disclosure, its application, or use. It should be understood that throughout the drawings, corresponding reference numerals denote the same or corresponding parts and features. As used herein, the term "module" refers to processing circuitry that may include application-specific integrated circuits (ASICs), electronic circuitry, processor (shared, dedicated, or group) and memory executing one or more software or firmware programs, combinational logic circuitry, and / or other suitable components that provide the described functionality.
[0032] As used herein, the term controller refers to a system comprising at least one processor and memory, wherein the system is arranged to control the operation of a function. The system may be a dedicated controller comprising a single processor and corresponding memory, a general-purpose controller comprising a processor and memory storing modules for enabling one or more processors to operate functions, a distributed system comprising multiple distributed processors and memories communicating with each other and configured to operate functions in combination with each other, or any similar system capable of controlling functions.
[0033] In a general implementation of the system disclosed herein, the vehicle controller receives a warning that the vehicle's internal combustion engine (ICE) is about to be engaged. In response to the warning, the vehicle controller identifies the target temperature of the sensing element of one or more oxygen (O2) sensors and engages the sensor heater to raise the sensing element to the target temperature before ICE activation. The ICE operates with closed-loop fuel control using the O2 sensor throughout the entire duration of ICE operation, thereby eliminating the initial warm-up period of open-loop fuel control.
[0034] According to an exemplary embodiment, Figure 1A top view of a hybrid electric vehicle 10 (vehicle 10) is shown. The relative positions of components and structures within vehicle 10 are provided for illustrative purposes and do not represent or imply actual positioning of components in this practical example. Vehicle 10 includes a body 12 defining a passenger compartment 14. A universal vehicle controller (controller 20) provides operational control for one or more systems within vehicle 10. In alternative examples, the controller may be replaced or supplemented by a dedicated system controller that operates in conjunction with the vehicle to provide control of vehicle 10.
[0035] Controller 20 provides control signals to ICE 30 and electric drive motor 40. Both ICE 30 and electric drive motor 40 are connected to wheels 70, such that rotation is supplied from ICE 30 and / or electric drive motor 40 to wheels 70. Drive motor 40 is connected to an energy storage system (energy storage system 42), wherein energy storage system 42 provides power to drive motor 40. Energy storage system 42 communicates with controller 20, wherein controller 20 monitors the charging and energy storage parameters of energy storage system 42 according to any conventional monitoring system.
[0036] A pair of O2 sensors 50 and 60 are connected to controller 20 and provide a sensor output indicating the O2 level in the exhaust gas from the ICE 30 at the location of O2 sensors 50 and 60. In the example of vehicle 10, the first of the O2 sensors 50 is located upstream of the catalytic converter within the exhaust system and is referred to as the pre-sensor. The second of the O2 sensors is located downstream of the catalytic converter and is referred to as the post-sensor 60. In alternative examples, the process described herein can be applied to additional or alternatively located O2 sensors (e.g., O2 sensors within the catalytic converter).
[0037] Each sensor 50, 60 includes a corresponding sensing element 52, 62 and a corresponding sensor heater 54, 64. During the preprocessing step, power is supplied to the sensor heaters 54, 64 according to a duty cycle controlled by the controller 20. Operational control signals for defining and controlling the duty cycle and power supply can be provided according to any conventional method. The power causes the sensor heaters(one or more) 54, 64 to raise the temperature of the corresponding sensing element 52, 62.
[0038] To minimize tailpipe emissions from the hybrid electric vehicle, controller 20 includes a process for monitoring indications that the ICE 30 is about to start (referred to as a pre-start notification), and in response to the pre-start notification, performs a preheating process for sensors 50, 60. The preheating sensing elements 52, 62 allow the ICE 30 to operate in a closed-loop fuel control mode throughout the ignition cycle without potential condensation damage.
[0039] Continue to refer to Figure 1 , Figure 2 The procedure 200 for initializing O2 sensors 50 and 60 before ICE 30 starts is shown, thereby ensuring that ICE 30 operates with closed-loop fuel control throughout the ignition cycle.
[0040] Initially, controller 20 receives a pre-start notification at step 210. The pre-start notification is a signal available to controller 20 that indicates that ignition of the ICE 30 is imminent.
[0041] When the vehicle is a hybrid electric vehicle, such as in Figure 1 In vehicle 10, pre-start notification can be achieved by monitoring the charging state and charge maintenance limit of energy storage unit 42. When the charge state of energy storage unit 42 drops below the charge maintenance limit, this indicates that ICE 30 is about to start and step 210 occurs.
[0042] In an alternative example, the pre-start notification can be delivered via other indicators that the ICE 30 is about to ignite. For example, key fob proximity detection can identify that the driver's key fob (or other token object) is approaching vehicle 10. Based on this characteristic, the controller recognizes that the user is about to start vehicle 10 and triggers the receiving pre-start notification step 210. Similarly, when the user operates one or more vehicle systems (e.g., climate control, window control, etc.) to indicate that the user is ready to operate vehicle 10, the controller 20 can recognize that ICE 30 ignition is about to occur and trigger the receiving pre-start notification step 210.
[0043] Upon receiving the pre-start notification, the controller 20 responds by determining the target temperature of the sensing elements 52 and 62 of the O2 sensors 50 and 60 and comparing the current temperature of the O2 sensing elements 52 and 62 with the target temperature in the comparison check step 220.
[0044] The target temperature depends on the dew point of the O2 sensing elements 52 and 62, and can be determined according to the following formula:
[0045]
[0046] Where (Td) is the dew point temperature in degrees Celsius, (T) is the air temperature in degrees Celsius, (RH) is the relative humidity as a percentage, and (b) and (c) are constants. In one example, the constants are b = 17.625 and C = 243.04°C. The specific temperature can be determined using available sensors and sensing systems, such as mass airflow sensors.
[0047] The target temperature (Td) provides a threshold above which no preheating of sensing elements 52, 62 is required (i.e., the sensing elements are warm enough that condensation does not form). When the temperature of sensing elements(1) 52, 62 is below the threshold, preheating is required to ensure that condensation does not occur on sensing elements(1) 52, 62.
[0048] When the comparison check step 220 determines that the temperature of the sensing elements 52 and 62 is greater than or equal to the threshold, the process 200 continues to start the engine in the engine start step 230, where the engine operates under closed-loop fuel control, after which the engine operates normally.
[0049] When the temperatures of sensing elements 52 and 62 are below a threshold, process 200 continues to power heaters 54 and 64 in the power-on O2 heater step 240. To conserve power and prevent accidental heating overshoot (heating sensing elements 52 and 62 above their target temperature) that could exert excessive stress on sensing elements(s) 52 and 62, controller 20 adjusts the amount of power supplied to heaters 54 and 64 based on the difference between the temperature of sensing elements 52 and 62 and their dew point. In one example, the amount of power supplied to heaters 54 and 64 is adjusted by changing the duty cycle of heaters 54 and 64.
[0050] Continue to refer to Figure 1 and Figure 2 , Figure 3 Graph 300 shows the relationship between the heater duty cycle (y-axis) and the difference between the temperature and dew point temperature (x-axis) of sensing elements 52 and 62. As graph 300 shows, the duty cycle increases to 100% as the difference increases, and then plateaus at 100%. A 100% duty cycle represents the maximum amount of power that can be supplied to heaters 54 and 64, and the temperature can increase most rapidly. The specific curve for a given embodiment depends on the actual components and can be determined by those skilled in the art.
[0051] Once the duty cycle is determined, process 200 supplies power to the sensor heaters 54 and 64 and heats the O2 sensor in step 250, where the O2 sensor is heated. In some examples, such as Figure 2 In the example shown, the duty cycle determination at step 240 and the heating of sensing elements 52 and 62 are continuously cycled until the sensing elements 52 and 62 reach the target temperature, thereby allowing continuous adjustment of the supplied power and minimizing any overshoot.
[0052] In an alternative example, process 200 may calculate the duty cycle once and heat the sensor heaters 54 and 64 at that duty cycle until the target temperature is met.
[0053] Once the target temperature is reached, process 200 proceeds to engine start step 230.
[0054] In some examples, the pre-start notification may be very close to the user-initiated operation for the engine cycle preheating process 200 (which raises the sensing element temperature above the target temperature before ignition). In such examples, process 200 is still executed. While the user starts the ignition cycle and the heating step 250 is still being executed, the engine operates with open-loop fuel control until process 200 is complete, thus achieving at least some of the advantages of process 200.
[0055] By using Figure 2 In process 200, vehicle 10 can achieve instantaneous air / fuel closed-loop control, which allows fuel scheduling to follow a target curve as a function of intake valve temperature, thereby optimizing emissions performance, reducing engine output and tailpipe emissions, and improving converter ignition performance. This benefit is achieved without any dependence on market fuel variability, improving combustion stability within the ICE 30, reducing fuel consumption, and improving emissions performance.
[0056] The term “a” does not indicate a limitation of quantity, but rather that at least one of the referenced items is present. Unless the context clearly indicates otherwise, the term “or” means “and / or”. Throughout the specification, the reference to “aspect” means that a particular element described in connection with that aspect (e.g., a feature, structure, step, or characteristic) is included in at least one aspect described herein and may or may not be present in other aspects. Furthermore, it should be understood that the described elements may be combined in any suitable manner in the aspects.
[0057] When an element, such as a layer, film, region, or substrate, is referred to as being “on” another element, it can be directly on the other element, or there may be intermediate elements present. Conversely, when an element is referred to as being “directly” on another element, there are no intermediate elements present.
[0058] Unless otherwise stated herein, all test standards are the most recent standards in force as of the filing date of this application, or, if priority is claimed, the filing date of the earliest priority application in which a test standard appears.
[0059] Unless otherwise defined, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.
[0060] While the foregoing disclosure has been described with reference to exemplary embodiments, those skilled in the art will understand that various changes can be made and elements can be substituted with equivalents without departing from its scope. Furthermore, many modifications can be made to adapt particular situations or materials to the teachings of this disclosure without departing from the basic scope of this disclosure. Therefore, it is intended that this disclosure be limited to the specific embodiments disclosed, but will include all embodiments falling within its scope.
Claims
1. A vehicle comprising: At least a first oxygen sensor, the first oxygen sensor including a sensing element and a heating element; Energy storage system; Internal combustion engine; A controller controllably connected to the energy storage system, connected to the internal combustion engine, and communicating with the at least first oxygen sensor, the controller including an oxygen sensor wake-up module configured to: respond to a received pre-start notification indicating that the internal combustion engine is about to start by comparing the temperature of the sensing element of the first oxygen sensor with a target temperature, heating the sensing element until the sensing element reaches at least the target temperature when the heating element is below the target temperature, and starting the internal combustion engine after heating the sensing element.
2. The vehicle according to claim 1, wherein the at least first oxygen sensor includes a second oxygen sensor, and wherein the oxygen sensor wake-up module controls the first oxygen sensor and the second oxygen sensor.
3. The vehicle of claim 1, wherein the vehicle is a hybrid electric vehicle, and wherein the pre-start notification is that the state of charge of the energy storage system has dropped below the energy storage system's charge maintenance limit.
4. The vehicle of claim 1, wherein the pre-start notification is a token object indicating a predetermined proximity to the vehicle.
5. The vehicle of claim 1, wherein the pre-start notification is an operator's action on at least one vehicle system.
6. The vehicle of claim 1, wherein starting the internal combustion engine after heating the sensing element to the threshold temperature includes starting the internal combustion engine under closed-loop fuel control.
7. The vehicle of claim 1, wherein heating the sensing element until the sensing element reaches at least the target temperature when the heating element is below the target temperature comprises: Power is supplied to the heater according to a duty cycle, wherein the duty cycle depends on the difference between the temperature of the sensing element and the target temperature.
8. The vehicle according to claim 7, wherein, The target temperature is the dew point of the sensing element.
9. The vehicle of claim 7, wherein comparing the temperature of the sensing element of the first oxygen sensor with the target temperature is performed continuously until the internal combustion engine is started, and wherein the duty cycle is adjusted based on the current difference between the temperature of the sensing element and the target temperature.
10. A vehicle controller including a processor and a non-transitory memory storing an oxygen sensor wake-up module, wherein the oxygen sensor wake-up module is configured to: respond to a received pre-start notification indicating that the internal combustion engine is about to start by comparing the temperature of a sensing element of a first oxygen sensor with a target temperature, and heating the sensing element until the sensing element reaches at least the target temperature when the sensing element is below the target temperature, and starting the internal combustion engine after heating the sensing element.