FAST-AWAKENING OXYGEN PROBE

Abstract

A vehicle comprises at least one first oxygen sensor, which includes a sensor element and a heater. The vehicle also comprises an electrical energy storage system, an internal combustion engine, and a control unit that is controllably coupled to the electrical energy storage system and the internal combustion engine and communicates with the at least one first oxygen sensor. The control unit includes an oxygen sensor wake-up module configured to respond to the receipt of a pre-start message by the control unit indicating an impending start of the internal combustion engine. It does this by comparing the temperature of the first oxygen sensor's sensor element with a target temperature and heating the sensor element until it reaches at least the target temperature. If the heating element is below the target temperature, the first oxygen sensor's temperature is then heated, and the internal combustion engine is started after the sensor element has heated up.

Description

[0001] The subject of the disclosure relates to vehicles and in particular a system for waking up an oxygen probe.

[0002] Vehicles, including internal combustion engines (ICEs), use oxygen (O2) sensors to enable closed-loop fuel control based on the O2 sensor readings. Closed-loop fuel control allows for an ideal compromise between various emissions criteria while reducing fluctuations resulting from tolerances, vehicle aging, test parameters, and other factors, thereby minimizing internal combustion engine emissions.

[0003] However, if O2 probes are switched on while the probe element temperature is too low, condensation can occur, causing water droplets to form on the probe element. Operating the probe element while water droplets are present can lead to cracking, damaging the O2 probe and potentially requiring its replacement. Preconditioning the O2 probe by adjusting the probe element temperature using a heater allows the probe to operate without the risk of condensation.

[0004] In existing systems, preconditioning leads to a delay of several seconds after the ICE engine starts, before the O2 sensor can be activated. During this time, fuel control operates in an open-loop manner, and exhaust emissions are less effectively controlled.

[0005] It is desirable to minimize or eliminate open-loop fuel control and thereby improve exhaust emission control.

[0006] DE 10 2023 127 720 A1 discloses a method for preheating an aftertreatment component, in which a duty cycle for a heating element is determined based on the difference between a current temperature and a target temperature to control power consumption. DE 10 2021 118 712 A1 describes a system in which the heating of an exhaust gas sensor is activated before the start of the internal combustion engine, so that the sensor is ready for operation at the time of starting and cold-start emissions can be detected. DE 11 2006 003 529 B4 teaches the preheating of an air mass meter when an impending start of the internal combustion engine is detected, for example by opening a vehicle door or inserting a key. DE 101 50 510 A1 discloses the preheating of a heat-activated sensor before a cold start and the subsequent self-starting of the internal combustion engine in order to reduce exhaust emissions during a cold start.DE 10 2022 210 439 A1 describes a method for a hybrid vehicle in which the combustion engine is started when the state of charge of the battery falls below a certain threshold in order to recharge the battery. SUMMARY

[0007] A vehicle comprises at least one first oxygen sensor, the first oxygen sensor comprising a sensor element and a heating element. The vehicle also comprises an electrical energy storage system, an internal combustion engine, and a control unit that is controllably coupled to the electrical energy storage system and the internal combustion engine, and with which the at least one first oxygen sensor communicates.The control unit includes an oxygen sensor wake-up module configured to respond to a pre-start message from the control unit indicating an impending engine start. This is achieved by comparing the temperature of the first oxygen sensor's sensor element with a target temperature and heating the sensor element until it reaches at least the target temperature. If the sensor element is below the target temperature, the module starts the engine after the sensor element has heated up. Heating the sensor element to at least the target temperature involves supplying power for the heater according to a duty cycle. The duty cycle depends on the difference between the sensor element's temperature and the target temperature. The target temperature is the dew point of the sensor element.

[0008] In addition to one or more of the features described herein, the at least one first oxygen probe comprises a second oxygen probe, and wherein the oxygen probe wake-up module controls the first oxygen probe and the second oxygen probe.

[0009] In addition to one or more of the features described herein, the vehicle is a hybrid electric vehicle and the pre-start message is a state of charge of the electrical energy storage system that falls below a charge maintenance limit of the electrical energy storage system.

[0010] In addition to one or more of the features described herein, the pre-start message is a token object that enters a predefined proximity of the vehicle.

[0011] In addition to one or more of the features described herein, the pre-start message is the activation of at least one vehicle system by an operator.

[0012] In addition to one or more of the features described herein, starting the internal combustion engine after the probe element has heated up to the threshold temperature includes starting the internal combustion engine in a closed-loop fuel control system.

[0013] In addition to one or more of the features described herein, the comparison of the temperature of the probe element of the first oxygen probe with the target temperature is performed continuously until the combustion engine is started, and the duty cycle is set based on a current difference between the temperature of the probe element and the target temperature.

[0014] A vehicle control unit comprises a processor and non-transient memory. The non-transient memory stores an oxygen probe wake-up module.The oxygen sensor wake-up module is configured to respond to a pre-start notification indicating an impending combustion engine start by comparing the temperature of a probe element of a first oxygen sensor with a target temperature. If the probe element is below the target temperature, it heats the sensor element until it reaches at least the target temperature. Once the sensor element is heated, the combustion engine is started. Heating the sensor element to at least the target temperature involves supplying power for the heater according to a duty cycle. The duty cycle depends on the difference between the sensor element temperature and the target temperature. The target temperature is the dew point of the sensor element.

[0015] In addition to one or more of the features described herein, starting the internal combustion engine after the probe element has heated up includes starting the internal combustion engine in a closed-loop fuel control mode.

[0016] In another exemplary embodiment, the method for waking up an oxygen sensor in a vehicle comprises receiving a pre-start message indicating an impending start of an internal combustion engine, comparing the temperature of a sensor element of a first oxygen sensor with a target temperature, heating the sensor element until it reaches at least the target temperature if the heating element is below the target temperature in response to the pre-start message, and starting the internal combustion engine following the heating of the sensor element.

[0017] In addition to one or more of the features described herein, the method further comprises comparing the temperature of a probe element of a second oxygen probe with a target temperature and heating the probe element of the second oxygen probe until the probe element of the second oxygen probe is at least at the target temperature when the probe element of the second oxygen probe is below the target temperature in response to the pre-start message.

[0018] In addition to one or more of the features described herein, the pre-start message is a state of charge of the electrical energy storage system that falls below a charge maintenance limit of the electrical energy storage system, and wherein the first oxygen probe is an oxygen probe of a hybrid electric vehicle.

[0019] In addition to one or more of the features described herein, the pre-start message is a token object that enters a predefined proximity of a vehicle.

[0020] In addition to one or more of the features described herein, the pre-start message is the activation of at least one vehicle system by an operator.

[0021] In addition to one or more of the features described herein, starting the internal combustion engine after the probe element has been heated includes starting the internal combustion engine in a closed-loop fuel control system.

[0022] In addition to one or more of the features described herein, the comparison of the temperature of the probe element of the first oxygen probe with the target temperature is performed continuously until the combustion engine is started, and the duty cycle is set based on a current difference between the temperature of the probe element and the target temperature.

[0023] The aforementioned features and advantages, as well as other features and advantages of the disclosure, are readily apparent from the following detailed description in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Further features, advantages and details are listed only as examples in the following detailed description, which refers to the drawings, where: Fig. 1 is a schematic view of a hybrid electric vehicle; Fig. 2 a method for preconditioning an oxygen (O2) probe for the vehicle of Fig. 1 is; and Fig. Figure 3 is a diagram illustrating a relationship between the temperature of the O2 probe and a heating work cycle. DETAILED DESCRIPTION

[0025] The following description is merely exemplary and is not intended to limit the present disclosure, its application, or its use. It should be understood that in the drawings, corresponding reference numerals denote identical or corresponding parts and features. As used herein, the term "module" refers to a processing circuit that may include an application-specific integrated circuit (ASIC), an electronic circuit, a processor (common, dedicated, or group), memory executing one or more software or firmware programs, a combinational logic circuit, and / or other suitable components providing the described functionality.

[0026] As used herein, the term "control unit" refers to a system comprising at least one processor and memory arranged to control the operation of a function. The system may be a dedicated control unit comprising a single processor and corresponding memory; a general-purpose control unit comprising processors and memory containing modules that cause one or more of the processors to execute the function; a distributed system comprising multiple distributed processors and memory units communicating with each other and configured to execute the function in communication with each other; or a similar system capable of controlling the function.

[0027] In a general embodiment of the system disclosed herein, a vehicle control unit receives an advance warning that a vehicle internal combustion engine (ICE) is about to be started. In response to this advance warning, the vehicle control unit identifies a target temperature for a probe element of one or more oxygen (O2) sensors and activates a probe heater to raise the probe element to the target temperature before the ICE is started. The ICE is operated with closed-loop fuel control, which uses the O2 sensor(s) for the entire duration of the combustion engine's operation, thus eliminating an initial warm-up phase of open-loop fuel control.

[0028] An exemplary embodiment illustrates Fig. Figure 1 shows a top view of a hybrid electric vehicle 10 (vehicle 10). The relative locations of components and structures within the vehicle 10 are provided for illustrative purposes only and do not represent the actual positioning of the components in a practical example. The vehicle 10 comprises a body 12, which defines a passenger compartment 14. A general vehicle control unit (control unit 20) controls the operation of one or more systems within the vehicle 10. In alternative examples, the control unit may be replaced or supplemented by specialized system control units that work together to provide control for the vehicle 10.

[0029] The control unit 20 provides control signals for an ICE 30 and an electric drive motor 40. Both the ICE 30 and the electric drive motor 40 are connected to the wheels 70, so that the rotary motion from the ICE 30 and / or the electric drive motor 40 is transmitted to the wheels 70. The electric drive motor 40 is connected to an electrical energy storage system (energy storage system 42), which provides electrical energy to the electric drive motor 40. The energy storage system 42 communicates with the control unit 20, which monitors the charging and energy storage parameters of the energy storage system 42 according to any conventional monitoring system.

[0030] A pair of O2 sensors 50, 60 is connected to the control unit 20 and provides sensor outputs indicating the O2 content within the exhaust gas of the ICE 30 at the location of the O2 sensors 50, 60. In the example of vehicle 10, a first O2 sensor 50 is located upstream of a catalyst in the exhaust system and is referred to as the upstream sensor. A second O2 sensor is located downstream of the catalyst and is referred to as the downstream sensor 60. In alternative examples, the procedures described herein can be adapted for additional or alternatively positioned O2 sensors (e.g., an O2 sensor inside the catalyst).

[0031] Each probe 50, 60 comprises a corresponding probe element 52, 62 and a corresponding probe heater 54, 64. During a preconditioning step, electrical energy is supplied to the probe heater(s) 54, 64 according to a duty cycle, the duty cycle being controlled by the controller 20. The operating control signals, which define and control the duty cycle and the power supply, can be provided by any conventional method. The electrical energy causes the probe heater(s) 54, 64 to increase the temperature of the corresponding probe element 52, 62.

[0032] To minimize the exhaust emissions of a hybrid electric vehicle, the control unit 20 includes a process that monitors for signs that the ICE 30 is about to start (referred to as pre-start messages) and, in response to the pre-start message, activates a probe 50, 60 for preheating. Preheating the probe element 52, 62 allows the ICE 30 to operate in closed-loop fuel control mode throughout the entire ignition cycle without potential condensation damage.

[0033] With further reference to Fig. 1, Fig. Figure 2 illustrates a procedure 200 for initializing the O2 sensors 50, 60 prior to ignition of the ICE 30, thereby ensuring that the ICE 30 operates in closed-loop fuel control mode during an entire ignition cycle.

[0034] First, the control unit 20 receives a pre-start message in step 210 (receive pre-start message). The pre-start message is a signal available to the control unit 20 indicating that the ignition of the ICE 30 is imminent.

[0035] If the vehicle is a hybrid electric vehicle, as with vehicle 10 of Fig. 1. The pre-start notification can be triggered by monitoring the state of charge and the charge maintenance limit of the energy storage unit 42. If the state of charge of the energy storage unit 42 falls below the charge maintenance limit, this indicates that the ICE 30 will start shortly, and step 210 is initiated.

[0036] In alternative examples, the pre-start message can also be triggered by other indicators that suggest the ignition of the ICE 30 is imminent. For instance, the detection of a key fob's proximity can identify that the driver's key fob (or another object) is approaching the vehicle 10. Based on this feature, the control unit identifies that the user is about to start the vehicle 10, and step 210, "Receive pre-start message," is executed. Similarly, the control unit 20 can identify that ignition of the ICE 30 is imminent if a user operates one or more vehicle systems (e.g., climate control, window control, etc.), indicating that the user is preparing to operate the vehicle 10, and trigger step 210, "Receive pre-start message."

[0037] After a pre-start message has been received, the control unit 20 reacts by determining a target temperature of the probe element(s) 52, 62 of the O2 probe(s) 50, 60 and comparing a current temperature of the O2 probe element(s) 52, 62 with the target temperature in a comparative test 220.

[0038] The target temperature depends on the dew point of the O2 probe element(s) 52, 62 and can be determined according to: Ta=c⋅(b⋅Tc−T+ln(RH / 100))b−(b⋅Tc−T+ln(RH / 100)) where (Td) is the dew point temperature in degrees Celsius, (T) is the air temperature in degrees Celsius, (RH) is the relative humidity in percent, and (b) and (c) are constants. In an example, the constants are b = 17.625 and c = 243.04 °C. The specific temperatures can be determined using available probes and measuring systems such as mass airflow sensors.

[0039] The target temperature (Td) provides a threshold above which preheating of the probe element(s) 52, 62 is not required (i.e., the probe element is warm enough that no condensation occurs). If the temperature of the probe element(s) 52, 62 is below the threshold, preheating is required to ensure that no condensation occurs on the probe element(s) 52, 62.

[0040] If the comparative test 220 determines that the temperature of the probe element(s) 52, 62 is greater than or equal to the threshold value, the procedure 200 proceeds to start the engine, with the engine being operated in a closed-loop fuel control system during an engine start step 230, after which the engine operation continues normally.

[0041] If the temperature of the probe element(s) 52, 62 falls below the threshold, process 200 switches on the heating device(s) 54, 64 in step 240 to activate the O2 heater. To conserve power and prevent accidental overheating (heating of the probe element(s) 52, 62 above the target temperature), which could overload the probe element(s) 52, 62, the control unit 20 adjusts the amount of power supplied to the heater(s) 54, 64 based on the difference between the temperature of the probe element(s) 52, 62 and the dew point. For example, the amount of power supplied by the heater(s) 54, 64 is adjusted by changing the duty cycle of the heater(s) 54, 64.

[0042] With further reference to Fig. 1 and Fig. 2 is Fig. 3. Diagram 300 illustrates the relationship between the heating duty cycle (y-axis) and the difference between the temperature of the probe element(s) 52, 62 and the dew point temperature (x-axis). As shown in Diagram 300, the duty cycle increases with increasing difference up to 100%, and then remains at 100%. A duty cycle of 100% represents the maximum power that can be supplied to the heater(s) 54, 64, and the temperature can be raised most rapidly. The specific curve for a given implementation depends on the practical components and can be determined by a specialist.

[0043] Once the duty cycle has been determined, process 200 switches on the probe heater(s) 54, 64 and heats the O2 probe in a step 250 to heat the O2 probe. In some examples, such as the illustrated example in Fig. 2. The duty cycle determination in step 240 and the heating of the probe element(s) 52, 62 are carried out continuously in a loop until the probe element(s) 52, 62 reach the target temperature, thereby continuously adjusting the provided power and minimizing overshoot.

[0044] In alternative examples, process 200 can calculate the work cycle only once, and the probe heater(s) 54, 64 are heated with this work cycle until the target temperature is reached.

[0045] Once the target temperature is reached, process 200 continues with step 230 to start the engine.

[0046] In some examples, the pre-start signal may arrive too shortly before the user initiates an engine cycle, allowing preheating process 200 to raise the probe element temperatures above the target temperature before ignition. In such examples, process 200 continues to run. If the user initiates the ignition cycle and heating stage 250 is still running, the engine will operate with open-loop fuel control until process 200 is complete, thereby achieving at least some of the benefits of process 200.

[0047] By applying procedure 200 of Fig.2. The vehicle 10 can achieve immediate air / fuel control, allowing the fuel metering to follow a target profile depending on the intake valve temperature. This optimizes emissions performance, reduces engine exhaust emissions, and improves converter lighting performance. This advantage is achieved without relying on market fluctuations in fuel prices and improves combustion stability within the ICE 30, reduces fuel consumption, and enhances emissions performance.

[0048] The terms "a / a / r / s" do not imply a limitation of quantity, but rather denote the presence of at least one of the mentioned items. The term "or" means "and / or" unless the context clearly indicates otherwise. When the entire description refers to "an aspect," this means that a particular element (e.g., a feature, a structure, a step, or a property) described in connection with the aspect is encompassed in at least one of the aspects described herein and may or may not be present in other aspects. Furthermore, it is understood that the described elements can be combined in any suitable way across the various aspects.

[0049] When an element such as a layer, film, area, or substrate is described as lying "on" another element, it may lie directly on top of the other element, or there may be elements in between. Conversely, when an element is described as lying "directly on" another element, there are no elements in between.

[0050] Unless otherwise specified herein, all testing standards are the latest standard in force on the filing date of this application or, if priority is claimed, the filing date of the earliest priority application in which the testing standard appears.

[0051] Unless otherwise defined, the technical and scientific terms used herein have the same meanings as generally understood by a person skilled in the art in which this disclosure belongs.

[0052] Although the foregoing disclosure has been described with reference to exemplary embodiments, it is known to those skilled in the art that various modifications can be made and equivalent elements substituted without altering the scope of application. Furthermore, many modifications can be made to adapt a particular situation or material to the teachings of the disclosure without deviating from its essential scope. Therefore, the present disclosure is not intended to be limited to the specific embodiments disclosed, but rather to encompass all embodiments that fall within its scope.

Claims

[1] Vehicle (10), comprising: at least one first oxygen probe (50), wherein the first oxygen probe (50) comprises a probe element (52) and a heating element; a storage system (42) for electrical energy; an internal combustion engine; a control unit (20) that is controllably coupled to the electrical energy storage system (42) and the internal combustion engine, and is in communication with the at least one first oxygen sensor (50), wherein the control unit (20) comprises an oxygen sensor wake-up module configured to respond to the receipt of a pre-start message by the control unit (20) indicating an impending start of the internal combustion engine by comparing a temperature of the sensor element (52) of the first oxygen sensor (50) with a target temperature and heating the sensor element (52) until the sensor element (52) is at least at the target temperature, if the heating element is below the target temperature, and starting the internal combustion engine after the sensor element (52) has been heated; wherein heating the probe element (52) until the probe element (52) is at least at the target temperature includes providing power for heating according to a duty cycle, and wherein the duty cycle depends on a difference between the temperature of the probe element (52) and the target temperature; where the target temperature is a dew point of the probe element (52). [2] Vehicle (10) according to claim 1, wherein the at least one first oxygen probe (50) comprises a second oxygen probe (60), and wherein the oxygen probe wake-up module controls the first oxygen probe (50) and the second oxygen probe (60). [3] Vehicle (10) according to claim 1, wherein the vehicle (10) is a hybrid electric vehicle, and wherein the pre-start message is a charge state of the electrical energy storage system (42) that falls below a charge maintenance limit of the electrical energy storage system (42). [4] Vehicle (10) according to claim 1, wherein the pre-start message is a token object that enters a predefined proximity of the vehicle (10). [5] Vehicle (10) according to claim 1, wherein the pre-start message is the activation of at least one vehicle system by an operator. [6] Vehicle (10) according to claim 1, wherein starting the internal combustion engine after heating the probe element (52) to the threshold temperature comprises starting the internal combustion engine in a closed-loop fuel control system. [7] Vehicle (10) according to claim 1, wherein the comparison of the temperature of the probe element (52) of the first oxygen probe (50) with the target temperature is carried out continuously until the internal combustion engine is started, and wherein the duty cycle is set based on a current difference between the temperature of the probe element (52) and the target temperature. [8] Vehicle control unit (20) comprising a processor and a non-transient memory, wherein the non-transient memory stores an oxygen sensor wake-up module, the oxygen sensor wake-up module being configured to respond to the receipt of a pre-start notification indicating an impending start of an internal combustion engine by comparing a temperature of a sensor element (52) of a first oxygen sensor (50) with a target temperature and causing the sensor element (52) to be heated until the sensor element (52) is at least at the target temperature if the heating element is below the target temperature, and causing the internal combustion engine to be started after the sensor element (52) has been heated; wherein heating the probe element (52) until the probe element (52) is at least at the target temperature includes providing power for heating according to a duty cycle, and wherein the duty cycle depends on a difference between the temperature of the probe element (52) and the target temperature; where the target temperature is a dew point of the probe element (52).

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