Systems and methods for reducing vehicle emissions

Abstract

This disclosure provides "systems and methods for reducing vehicle emissions." Methods and systems are provided for reducing the release of undesirable emissions into the atmosphere during the start-up event of an engine configured to propel a vehicle. In one example, one method includes providing an alternative heat source and actively delivering heat from said alternative heat source to a heated exhaust oxygen sensor, where the heating element configured to raise the temperature of said heated exhaust oxygen sensor is known to be degraded. In this way, a desired air-fuel ratio can be obtained during the engine start-up event even when the heating element used to raise the temperature of the sensor is degraded, which can therefore reduce exhaust tailpipe emissions that might otherwise be released without such mitigation action.

Description

Technical Field

[0001] This description generally relates to methods and systems for controlling a vehicle engine under conditions where the heated exhaust oxygen (HEGO) heater has deteriorated, in order to actively raise the temperature of the HEGO sensor during an engine start-up event. Background Technology

[0002] During a cold start event, the vehicle may be in open-loop fuel control until the heated exhaust oxygen sensor (HEGO) heats up to indicate the air-fuel ratio. During this open-loop control period, exhaust emissions may be higher than expected because the air-fuel ratio may not be at the optimal stoichiometric level (e.g., 14.7:1). Once the HEGO sensor warms up to its operating temperature, open-loop control can then be terminated, and closed-loop control can become effective, where the HEGO sensor is used to adjust fuel delivery to achieve / maintain the optimal air-fuel ratio. Furthermore, in many current non-hybrid vehicles, the catalytic converter is ignited by engine combustion heat, which may take several seconds before combustion byproduct gases can be oxidized via the catalyst.

[0003] Such issues can be exacerbated in hybrid electric vehicles (HEVs) and / or vehicles equipped with start / stop (S / S) capabilities, where the engine may pull down (e.g., be deactivated to stop burning air and fuel) when the vehicle speed decreases below a threshold speed. More specifically, for HEVs and / or S / S vehicles, there may be specific driving cycles in which the engine may shut off (e.g., not burn air and fuel), and during such modes (e.g., electric operation or idle stop), the catalyst and / or HEGO temperature may cool below the desired operating temperature. Therefore, in such examples, there may be increased emission levels upon subsequent engine start-up events until the catalyst and / or HEGO sensors heat up to their desired operating temperatures.

[0004] Therefore, due to these issues, recent advancements in the powertrains of HEVs and S / S vehicles have focused on electrically heated catalytic converters (EHC) and HEGO heating elements. In other words, EHCs can incorporate heating elements internally to activate the catalytic converter independently of engine combustion waste heat. Similarly, HEGO heating elements can raise the temperature of HEGO sensors independently of combustion waste heat.

[0005] However, HEGO heating elements or HEGO heaters can be prone to degradation because they are located in the harsh environment of the exhaust flow. When such HEGO heaters deteriorate, the HEGO sensor may take longer to heat up because the temperature rise becomes dependent solely on engine waste heat rather than active heating from its own HEGO heating element. In this case, the extra time required to heat up the HEGO sensor can lead to increased exhaust tailpipe emissions during cold starts or when the HEGO sensor temperature has already dropped below the desired temperature during S / S events. Summary of the Invention

[0006] The inventors of this paper have recognized the problems mentioned above and have developed systems and methods for solving them. In one example, one method includes reducing unwanted emissions during engine start-up events of a vehicle propelled by providing an alternative heat source and actively delivering heat from the source to the sensor to raise its temperature to its desired operating temperature, even when the heating element configured to heat the exhaust oxygen sensor is deteriorated. In this way, even under conditions where the heating element configured to heat the exhaust oxygen sensor is deteriorated, emissions can be improved more quickly by enabling the sensor to reach its desired operating temperature during engine start-up events.

[0007] As an example, the starting event includes a cold start event, and in another example, the starting even includes a start / stop event when the sensor temperature has decreased below its expected operating temperature while the engine is not burning air and fuel.

[0008] In another example, reducing unwanted emissions includes reducing unwanted emissions at the start-up event compared to conditions where a heated exhaust oxygen sensor remains below its desired operating temperature at the start-up event.

[0009] The advantages and other advantages and features described herein will readily become apparent from the following detailed description, taken alone or in conjunction with the accompanying drawings.

[0010] It should be understood that the above summary is provided to introduce, in a simplified form, a series of concepts further described in the detailed description. This is not intended to identify key or essential features of the claimed subject matter, the scope of which is uniquely defined by the claims following the detailed description. Furthermore, the claimed subject matter is not limited to implementations that address any of the shortcomings described above or in any part of this disclosure. Attached Figure Description

[0011] Figure 1An exemplary vehicle propulsion system is schematically shown.

[0012] Figure 2 An exemplary engine system with a fuel system and an evaporative emission system is schematically shown.

[0013] Figure 3 Another example of an engine system including an electric supercharger is shown schematically.

[0014] Figure 4 schematically shown Figures 1 to 3 A single cylinder of the engine system.

[0015] Figures 5A to 5B An exemplary H-bridge circuit is depicted that can be used to rotate a vehicle engine or electric compressor in a forward or reverse direction.

[0016] Figure 6 This paper describes an advanced exemplary method for proactively raising the temperature of an HEGO sensor based on current vehicle operating conditions.

[0017] Figure 7 An exemplary timeline is depicted for actively increasing the temperature of a HEGO sensor located upstream of the exhaust catalyst during an S / S event.

[0018] Figure 8 Another exemplary timeline depicts the temperature of the HEGO sensor located upstream of the exhaust catalyst during an S / S event.

[0019] Figure 9 Another exemplary timeline depicts the temperature of the HEGO sensor located upstream of the exhaust catalyst during an S / S event.

[0020] Figure 10 An exemplary timeline depicts the use of an HEGO sensor located upstream of the exhaust catalyst to actively raise the temperature during a cold start event.

[0021] Figure 11 An exemplary timeline is depicted for actively raising the temperature of an HEGO sensor located downstream of the exhaust catalyst during a cold start event. Detailed Implementation

[0022] The following description relates to systems and methods for actively raising the temperature of an HEGO sensor during an S / S event or a cold start event when the heating element of the HEGO sensor, which is coupled to a sensor located upstream or downstream of an emission control device, fails to operate as expected or anticipated. This method may include rotating the engine or electric supercharger without fuel to deliver heat from an alternative source to the specific HEGO sensor whose heating element has deteriorated. Therefore, it is possible to use such systems in hybrid electric vehicles, for example in... Figures 1 to 2 This method is performed in the vehicle / engine system described herein, wherein such a vehicle may include, for example, in Figure 3 The electric supercharger depicted in the engine system is shown below. In one example, the alternative heat source could be a heater connected to the emission control unit, while in another example, it could be via a laser ignition device, for example... Figure 4 The laser ignition device depicted here provides an alternative heat source. The rotation of the engine or electric supercharger can be performed via energy stored in an onboard energy storage device, and such rotation can include forward or reverse rotation of the engine or electric supercharger, depending on the specific method chosen to increase the temperature of the selected HEGO sensor. Therefore, an H-bridge circuit can be employed, for example in... Figures 5A to 5B The H-bridge circuit described here is used for forward / reverse rotation of the engine or electric supercharger.

[0023] exist Figure 6 The text describes a method for actively raising the temperature of an HEGO sensor located upstream or downstream. This method may include a controller assessing current vehicle operating conditions and specific component portions included in the engine system of such vehicles. Therefore, Figures 7 to 11 Describing for execution in Figure 6 The various timelines of different types of active HEGO heating methods are discussed in detail.

[0024] Figure 1 An exemplary vehicle propulsion system 100 is described. The vehicle propulsion system 100 includes a fuel-burning engine 110 and a motor 120. As a non-limiting example, the engine 110 includes an internal combustion engine and the motor 120 includes an electric motor. The motor 120 can be configured to utilize or consume energy sources different from those of the engine 110. For example, the engine 110 may consume liquid fuel (e.g., gasoline) to produce engine output, while the motor 120 may consume electrical energy to produce motor output. Therefore, a vehicle having the propulsion system 100 can be referred to as a hybrid electric vehicle (HEV).

[0025] The vehicle propulsion system 100 can utilize various operating modes depending on the operating conditions encountered by the vehicle propulsion system. Some of these modes allow the engine 110 to remain in a shut-off state (i.e., set to a deactivated state), in which combustion of fuel at the engine is stopped. For example, under selected operating conditions, when the engine 110 is deactivated, the motor 120 can propel the vehicle via the drive wheels 130, as indicated by arrow 122.

[0026] During other operating conditions, engine 110 can be deactivated (as described above), while motor 120 can be operated to charge energy storage device 150. For example, motor 120 can receive wheel torque from drive wheels 130, as indicated by arrow 122, whereby the motor can convert the vehicle's kinetic energy into electrical energy for storage in energy storage device 150, as indicated by arrow 124. This operation can be referred to as regenerative braking of the vehicle. Therefore, in some examples, motor 120 can provide generator functionality. However, in other examples, generator 160 can alternatively receive wheel torque from drive wheels 130, whereby the generator can convert the vehicle's kinetic energy into electrical energy for storage in energy storage device 150, as indicated by arrow 162. In some examples, motor 120 and generator 160 may comprise the same motor / generator.

[0027] During other operating conditions, engine 110 can be operated by burning fuel received from fuel system 140, as indicated by arrow 142. For example, when motor 120 is deactivated, engine 110 can be operated to propel the vehicle via drive wheels 130, as indicated by arrow 112. During other operating conditions, engine 110 and motor 120 can be operated separately to propel the vehicle via drive wheels 130, as indicated by arrows 112 and 122 respectively. This configuration, where the engine and motor can selectively propel the vehicle, can be referred to as a parallel-type vehicle propulsion system. It should be noted that in some examples, motor 120 can propel the vehicle via a first set of drive wheels, and engine 110 can propel the vehicle via a second set of drive wheels.

[0028] In other examples, the vehicle propulsion system 100 can be configured as a tandem type vehicle propulsion system, whereby the engine does not directly propel the drive wheels. Instead, the engine 110 can be operated to supply power to the motor 120, which in turn can propel the vehicle via the drive wheels 130, as indicated by arrow 122. For example, during selected operating conditions, the engine 110 can drive the generator 160, as indicated by arrow 116, which can then supply electrical energy to one or more of the motors 120, as indicated by arrow 114, or to the energy storage device 150, as indicated by arrow 162. As another example, the engine 110 can be operated to drive the motor 120, which can then provide generator functionality to convert engine output into electrical energy, which can be stored in the energy storage device 150 for later use by the motor.

[0029] In other examples, which will be discussed in detail below, motor 120 can be used to turn or rotate engine 110 in a configuration without fuel. More specifically, motor 120 can use electricity from an on-board energy storage device 150 to turn the engine without fuel, which may include, for example, a battery, capacitor, supercapacitor, etc. In the case where motor 120 is used to turn the engine without fuel, fuel injection into the engine cylinders can be prevented, and no spark (or laser-based ignition in some examples) can be provided to each of the engine cylinders. As will be discussed in more detail below, in some examples the engine can be turned or rotated in the forward or default direction without fuel, while in other examples the engine can be turned or rotated in the reverse direction without fuel. For example, an H-bridge circuit (see...) can be used. Figures 5A to 5B This allows the engine to rotate in either the forward or reverse direction. Furthermore, although in Figure 1 The location is not specified (but see [link]). Figure 3 However, in some examples, the vehicle propulsion system may include an electric supercharger or electric compressor that can be similarly controlled via a motor to rotate in a forward or reverse orientation.

[0030] In some examples, engine 110 may be configured with a start / stop (S / S) feature 183 (also referred to herein as an S / S system) communicatively coupled to control system 190, wherein control system 190 may automatically shut off internal combustion engine 110 (idle-stop) upon meeting selected idle-stop conditions or (in other words) a set of predetermined conditions without receiving an input to shut down the engine. These may include, for example, engine torque demand being less than a threshold, vehicle speed being below a threshold vehicle speed (e.g., 5 mph), onboard energy storage being fully charged (e.g., charged above a threshold charge state), no request for air conditioning being received, cabin heating, etc. Similarly, the engine may be automatically restarted in response to conditions such as: torque demand being higher than a threshold; a request to charge the battery (e.g., onboard energy storage); a request to operate the air conditioning compressor, etc. In one example, the engine may be restarted in response to an operator depressing the accelerator pedal after a period of inactivity (e.g., at a traffic signal). The engine can be started without fuel by a motor (e.g., 120) or electric motor connected to the engine crankshaft until the desired engine speed is reached. Afterward, the motor or electric motor can be deactivated, and fueling can resume. Engine combustion can then support engine rotation. This automatic start / stop reduces fuel consumption and exhaust emissions.

[0031] Fuel system 140 may include one or more fuel storage tanks 144 for storing fuel on the vehicle. For example, fuel tank 144 may store one or more liquid fuels, including (but not limited to): gasoline, diesel, and ethanol fuel. In some examples, fuel may be stored on the vehicle as a mixture of two or more different fuels. For example, fuel tank 144 may be configured to store a mixture of gasoline and ethanol (e.g., E10, E85, etc.) or a mixture of gasoline and methanol (e.g., M10, M85, etc.), whereby these fuels or fuel mixtures can be supplied to engine 110 as indicated by arrow 142. Other suitable fuels or fuel mixtures may be supplied to engine 110, where they can be burned to produce engine output. The engine output may be used to propel the vehicle, as indicated by arrow 112, or to recharge energy storage device 150 via motor 120 or generator 160.

[0032] In some examples, the energy storage device 150 may be configured to store electrical energy that can be supplied to other electrical loads residing in the vehicle (in addition to the motor), including cabin heating and air conditioning, engine starting, headlights, cabin audio and video systems, etc. As a non-limiting example, the energy storage device 150 may include one or more batteries and / or capacitors.

[0033] The control system 190 can communicate with one or more of the engine 110, motor 120, fuel system 140, energy storage device 150, and generator 160. The control system 190 can receive sensor feedback information from one or more of the engine 110, motor 120, fuel system 140, energy storage device 150, and generator 160. Furthermore, the control system 190 can send control signals to one or more of the engine 110, motor 120, fuel system 140, energy storage device 150, and generator 160 in response to this sensor feedback. The control system 190 can receive instructions from the vehicle operator 102 regarding the output of the vehicle propulsion system requested by the operator. For example, the control system 190 can receive sensor feedback from a pedal position sensor 194 that communicates with pedal 192. Pedal 192 can schematically refer to the brake pedal and / or accelerator pedal. Furthermore, in some examples, the control system 190 can communicate with a remote engine start receiver 195 (or transceiver) that receives a wireless signal 106 from a remote key 104 having a remote start button 105. In other examples (not shown), remote engine start can be initiated via a cellular phone or smartphone-based system, where the user's cellular phone sends data to a server and the server communicates with the vehicle to start the engine.

[0034] Energy storage device 150 can periodically receive electrical energy from a power source 180 residing outside the vehicle (e.g., not part of the vehicle), as indicated by arrow 184. As a non-limiting example, vehicle propulsion system 100 can be configured as a plug-in hybrid electric vehicle (PHEV), whereby electrical energy can be supplied from power source 180 to energy storage device 150 via power transmission cable 182. During a recharging operation of energy storage device 150 from power source 180, power transmission cable 182 can electrically connect energy storage device 150 and power source 180. When operating the vehicle propulsion system to propel the vehicle, power transmission cable 182 can be disconnected between power source 180 and energy storage device 150. Control system 190 can identify and / or control the amount of electrical energy stored at energy storage device, which may be referred to as state of charge (SOC).

[0035] In other examples, the electrical transmission cable 182 may be omitted, where electrical energy can be wirelessly received from the power source 180 at the energy storage device 150. For example, the energy storage device 150 may receive electrical energy from the power source 180 via one or more of electromagnetic induction, radio waves, and electromagnetic resonance. Therefore, it is understood that any suitable method can be used to recharge the energy storage device 150 from a power source that does not constitute part of the vehicle. In this way, the motor 120 can propel the vehicle by utilizing energy sources other than the fuel used by the engine 110.

[0036] The fuel system 140 can periodically receive fuel from a fuel source residing outside the vehicle. As a non-limiting example, the vehicle propulsion system 100 can be fueled by receiving fuel via a fuel dispensing device 170, as indicated by arrow 172. In some examples, the fuel tank 144 can be configured to store fuel received from the fuel dispensing device 170 until said fuel is supplied to the engine 110 for combustion. In some examples, the control system 190 can receive an indication of the level of fuel stored in the fuel tank 144 via a fuel level sensor. The level of fuel stored in the fuel tank 144 (e.g., identified by the fuel level sensor) can be communicated to the vehicle operator via, for example, a fuel gauge or indication in the vehicle dashboard 196.

[0037] The vehicle propulsion system 100 may also include an ambient temperature / humidity sensor 198 and a roll stability control sensor (e.g., lateral and / or longitudinal and / or yaw rate sensors 199). The vehicle instrument panel 196 may include indicator lights and / or a text-based display showing messages to the operator. The vehicle instrument panel 196 may also include various input elements for receiving operator input, such as buttons, touchscreens, voice input / recognition, etc. For example, the vehicle instrument panel 196 may include a fuel filler button 197 that the vehicle operator can manually actuate or press to initiate fuel filling. For example, in response to the vehicle operator actuating the fuel filler button 197, the fuel tank in the vehicle may be depressurized to allow fuel filling to be performed.

[0038] The control system 190 can communicatively connect to other vehicles or infrastructure using suitable communication technologies well known in the art. For example, the control system 190 can connect to other vehicles or infrastructure via a wireless network 131, which may include Wi-Fi, Bluetooth, cellular service types, wireless data transmission protocols, etc. The control system 190 can broadcast (and receive) information about vehicle data, vehicle diagnostics, traffic conditions, vehicle location information, vehicle operating procedures, etc., via vehicle-to-vehicle (V2V), vehicle-to-infrastructure-to-vehicle (V2I2V), and / or vehicle-to-infrastructure (V2I) technologies. The communication and information exchanged between vehicles can be direct between vehicles or multi-hop communication and information. In some examples, longer-range communication (e.g., WiMax) can be used instead of V2V or V2I2V, or combined with V2V or V2I2V, to extend the coverage area by several miles. In other examples, the vehicle control system 190 can communicatively connect to other vehicles or infrastructure via a wireless network 131 and the Internet (e.g., the cloud), which are generally known in the art.

[0039] Vehicle system 100 may also include an onboard navigation system 132 (e.g., a Global Positioning System) with which the vehicle operator can interact. Navigation system 132 may include one or more position sensors for assisting in estimating vehicle speed, vehicle altitude, vehicle position / location, etc. This information may be used to infer engine operating parameters, such as local air pressure. As discussed above, control system 190 may be further configured to receive information via the Internet or other communication networks. Information received from GPS may be cross-referenced with information available via the Internet to determine local weather conditions, local vehicle regulations, traffic information, etc. In one example, a route learning method may be combined with information received from GPS so that vehicle control system 190 can learn routes the vehicle typically travels. In some examples, the onboard navigation system may be additionally or alternatively combined with other sensors 133, such as lasers, radar, sonar, acoustic sensors, etc., to perform route learning of routes the vehicle typically travels. As an example, a transport-learning method may include information related to the learned duration of stops along a learned driving routine, where the engine may be stopped due to S / S characteristics. In some examples, the duration of a stop in which the engine can be turned off, which is learned in this way, may include information obtained wirelessly via a control system (e.g., via GPS and / or the Internet, V2V, V2I2V, etc.), where such information may include traffic light status (e.g., how long it takes for a particular traffic light to turn green), traffic conditions, etc., which may be related to the duration of a particular stop.

[0040] In some examples, vehicle system 100 may also include sensors specifically designed to indicate the occupancy status of the vehicle, such as seat force sensor 107, door sensing technology 108, and onboard camera 109.

[0041] Figure 2 A schematic depiction of vehicle system 206 is shown. It will be understood that vehicle system 206 may include components that interact with... Figure 1 The vehicle system 206 is the same as the vehicle system 100 depicted. Vehicle system 206 includes an engine system 208 coupled to an emission control system 251 and a fuel system 218. It is understood that the fuel system 218 may include components similar to those in the emission control system 251 and the fuel system 218. Figure 1 The fuel system 140 depicted is the same as the fuel system described above. The emission control system 251 includes a fuel vapor container or filter canister 222 that can be used to capture and store fuel vapor. In some examples, the vehicle system 206 may be a hybrid electric vehicle system.

[0042] Engine system 208 may include engine 110 having a plurality of cylinders 230. Although not explicitly shown, it is understood that each cylinder may include one or more intake valves and one or more exhaust valves. Engine 110 includes engine intake port 223 and engine exhaust system 225. Engine intake port 223 includes throttle valve 262 in fluid communication with engine intake manifold 244 via intake passage 242. Throttle valve 262 may include an electronic throttle valve that can be controlled via a vehicle controller that sends a signal to actuate the throttle valve to a desired position. In such examples where the throttle valve is electronic, the power used to control the throttle valve to the desired position may come from an on-board energy storage device (e.g., 150), such as a battery. Furthermore, engine intake port 223 may include an air box and filter 215 positioned upstream of throttle valve 262. Engine exhaust system 225 includes exhaust manifold 248 leading to exhaust passage 235, which delivers exhaust gas to the atmosphere. The engine exhaust system 225 may include one or more emission control devices or exhaust catalysts 270 that can be mounted in a tightly coupled location within the exhaust port. The one or more emission control devices may include a three-way catalytic converter, a lean NOx trap, a diesel particulate filter, an oxidation catalyst, etc. In some examples, the one or more emission control devices may include an electric heater 256 configured to raise the temperature of the emission control device to a desired operating temperature (e.g., ignition temperature). The electric heater may be controlled by a controller 212, which may send signals to an electric heater actuator 256a to actuate the electric heater to turn it on or off.

[0043] It will be understood that other components, such as various valves and sensors, can be included in the engine. For example, a bar pressure sensor 213 can be included in the engine intake. In one example, the bar pressure sensor 213 may be a manifold air pressure (MAP) sensor and may be coupled downstream of the throttle body 262 to the engine intake. The bar pressure sensor 213 may depend in part on the throttle body conditions, such as when the throttle body 262 is open to a threshold value, in order to accurately determine the BP (bottom pressure). Alternatively, the MAP can be inferred from alternative engine operating conditions, such as the mass airflow (MAF) measured by the MAF sensor 210 coupled to the intake manifold.

[0044] In some examples, the engine exhaust system 225 may also include a gasoline particulate filter (GPF) 217. GPF 217 may include a particulate filter, a hydrocarbon trap, a catalytic coating, or a combination thereof. In some examples, during operation of the engine 110, the GPF 217 can be periodically regenerated by operating at least one cylinder of the engine at a specific air-fuel ratio to increase the temperature of the GPF 217, such that retained hydrocarbons and soot particles can be oxidized. Although in Figure 2 While GPF is mentioned here, it is understood that in other examples, diesel particulate filters (DPF) may be included alternatively in the vehicle propulsion system.

[0045] In some examples, temperature sensor 226 may be located upstream of the inlet of GPF 217 and temperature sensor 229 may be located downstream of GPF 217. Temperature sensors 226 and 229 can be used to assess the temperature of GPF 217 for, for example, regeneration purposes. Additionally, pressure sensor 263 can assess the pressure in the exhaust system. For example, pressure sensor 263 may be a differential pressure sensor located upstream and downstream of GPF 217. Pressure sensor 263 can be used to determine the pressure at the inlet of GPF 217 to assess the operating conditions of the air to be introduced into GPF 217 for regeneration. Furthermore, in some examples, soot sensor 268 may be located downstream of GPF 217 to assess the level of soot released from GPF 217. Soot sensor 268 can be used to diagnose the operation of GPF 217 and other functions.

[0046] Fuel system 218 may include a fuel tank 220 coupled to fuel pump system 221. It will be understood that fuel tank 220 may include components described above... Figure 1The fuel tank 218 is the same as the fuel tank 144 depicted herein. The fuel pump system 221 may include one or more pumps for pressurizing fuel delivered to the injectors (e.g., the exemplary injector 266 shown) of the engine 110. Although only a single injector 266 is shown, additional injectors are provided for each cylinder. It will be understood that the fuel system 218 may be a non-return fuel system, a return fuel system, or various other types of fuel systems. The fuel tank 220 may hold multiple fuel mixtures, including fuels with a certain ethanol concentration range, such as various gasoline-ethanol mixtures, including E10, E85, gasoline, etc., and combinations thereof. A fuel level sensor 234 located in the fuel tank 220 may provide an indication of the fuel level (“fuel level input”) to the controller 212. As depicted, the fuel level sensor 234 may include a float connected to a variable resistor. Alternatively, other types of fuel level sensors may be used.

[0047] Vapor generated in fuel system 218 can be transported via vapor recovery line 231 to evaporative emission control system 251, which includes fuel vapor tank 222, and then flushed to engine intake port 223. Vapor recovery line 231 can be connected to fuel tank 220 via one or more conduits and can include one or more valves for isolating fuel tank during certain conditions. For example, vapor recovery line 231 can be connected to fuel tank 220 via one or more or a combination of conduits 271, 273, and 275.

[0048] Furthermore, in some examples, one or more fuel tank vent valves may be located in conduits 271, 273, or 275. Fuel tank vent valves can, in particular, allow the fuel vapor filter canister to be maintained at low pressure or vacuum without increasing the fuel evaporation rate from the emission control system (which would otherwise occur with reduced fuel tank pressure). For example, conduit 271 may include a staged vent valve (GVV) 287, conduit 273 may include a fill limit vent valve (FLVV) 285, and conduit 275 may include a staged vent valve (GVV) 283. Additionally, in some examples, recovery line 231 may be coupled to fuel filling system 219. In some examples, fuel filling system may include a fuel tank cap 205 for sealing the fuel filling system relative to atmosphere. Fuel filling system 219 is coupled to fuel tank 220 via fuel filling pipe or neck 211.

[0049] In addition, the fuel filling system 219 may include a fuel filler lock 245. In some examples, the fuel filler lock 245 may be a fuel tank cap locking mechanism. The fuel tank cap locking mechanism may be configured to automatically lock the fuel tank cap in a closed position, making it impossible to open the fuel tank cap. For example, when the pressure or vacuum in the fuel tank is greater than a threshold, the fuel tank cap 205 may be kept locked via the fuel filler lock 245. In response to a fuel filling request (e.g., a request initiated by the vehicle operator), the fuel tank may be depressurized, and the fuel tank cap may be unlocked after the pressure or vacuum in the fuel tank has dropped below a threshold. The fuel tank cap locking mechanism may be a latch or clutch that prevents the removal of the fuel tank cap when engaged. The latch or clutch may be electrically locked, for example, via a solenoid, or mechanically locked, for example, via a pressure diaphragm.

[0050] In some examples, the fuel filler lock 245 may be a filler valve located at the nozzle of the fuel filler pipe 211. In these examples, the fuel filler lock 245 may not prevent the removal of the fuel tank cap 205. Instead, the fuel filler lock 245 may prevent the fuel pump from being inserted into the fuel filler pipe 211. The filler valve may be electrically locked, for example, via a solenoid, or mechanically locked, for example, via a pressure diaphragm.

[0051] In some examples, the fuel filler lock 245 may be a fuel filler door lock, such as a latch or clutch that locks a fuel filler door located in a body panel of the vehicle. The fuel filler door lock may be electrically locked, for example, via a solenoid, or mechanically locked, for example, via a pressure diaphragm.

[0052] In an example where the fuel filler lock 245 is locked using an electrical mechanism, for example, the fuel filler lock 245 can be unlocked via a command from the controller 212 when the fuel tank pressure decreases below a pressure threshold. In an example where the fuel filler lock 245 is locked using a mechanical mechanism, for example, the fuel filler lock 245 can be unlocked via a pressure gradient when the fuel tank pressure decreases to atmospheric pressure.

[0053] The emission control system 251 may include one or more components for emission control, such as one or more fuel vapor filter canisters 222 filled with a suitable adsorbent 286b, the canisters being configured to temporarily trap fuel vapors (including vaporized hydrocarbons) and "operational losses" (i.e., fuel vaporized during vehicle operation, assuming the fuel tank is coupled to the filter canister under such conditions) during fuel tank refilling operations. In one example, the adsorbent 286b used is activated carbon. The emission control system 251 may also include a filter canister ventilation path or duct 227 that can deliver gases leaving the filter canister 222 to the atmosphere while storing or trapping fuel vapors from the fuel system 218.

[0054] The filter canister 222 may include a buffer 222a, each of which includes an adsorbent. As shown, the volume of the buffer 222a may be smaller than the volume of the filter canister 222 (e.g., a fraction of the filter canister volume). The adsorbent 286a in the buffer 222a may be the same as or different from the adsorbent in the filter canister (e.g., both may include charcoal). The buffer 222a may be positioned within the filter canister 222 such that during filter canister loading, fuel tank vapor is first absorbed into the buffer, and subsequently, when the buffer is saturated, other fuel tank vapor is absorbed into the filter canister. In contrast, during filter canister flushing, fuel vapor is first desorbed from the filter canister (e.g., reaching a threshold amount) and then desorbed from the buffer. In other words, the loading and unloading of the buffer are not synchronized with the loading and unloading of the filter canister. Therefore, the effect of the filter canister buffer is to suppress any fuel vapor peaks flowing from the fuel tank into the filter canister, thereby reducing the likelihood of any fuel vapor peaks reaching the engine. One or more temperature sensors 232 may be coupled to the filter canister 222 and / or within the filter canister. Heat is generated (heat of absorption) when fuel vapor is absorbed by the adsorbent in the filter canister. Similarly, heat is consumed when fuel vapor is desorbed by the adsorbent in the filter canister. In this way, the absorption and desorption of fuel vapor by the filter canister can be monitored and estimated based on the temperature changes within the filter canister.

[0055] While the stored fuel vapor is flushed from the fuel system 218 to the engine intake manifold 223 via flushing line 228 and flushing valve 261, ventilation line 227 can also allow fresh air to be drawn into filter canister 222. For example, flushing valve 261 may be normally closed but may be opened under certain conditions to provide a vacuum from engine intake manifold 244 to the fuel vapor filter canister for flushing. In some examples, ventilation line 227 may include an air filter 259 disposed upstream of filter canister 222.

[0056] In some examples, the flow rate of air and vapor between the filter canister 222 and the atmosphere can be regulated by a filter canister vent valve 297 connected within the ventilation duct 227. When the filter canister vent valve 297 is included, it can be a normally open valve, allowing the fuel tank isolation valve 252 (FTIV) to control the ventilation of the fuel tank 220 to the atmosphere. The FTIV 252 can be positioned between the fuel tank and the fuel vapor filter canister 222 within the duct 278. The FTIV 252 can be a normally closed valve, allowing fuel vapor from the fuel tank 220 to be discharged into the fuel vapor filter canister 222 when opened. The fuel vapor can then be discharged into the atmosphere or flushed into the engine intake system 223 via the filter canister flush valve 261. In some examples, the FTIV may not be included, while in others it may be included.

[0057] The fuel system 218 can be operated in multiple modes by the controller 212 through selective adjustment of various valves and solenoids. It is understood that the control system 214 may include components described above. Figure 1 The control system 190 described herein is the same control system. For example, the fuel system can be operated in a fuel vapor storage mode (e.g., during fuel tank refueling operation and when the engine is not burning air and fuel), wherein the controller 212 can close the canister flush valve (CPV) 261 while opening the isolation valve 252 (if included) to direct the refueling fuel vapor into the canister 222, while preventing the fuel vapor from being directed into the intake manifold.

[0058] As another example, the fuel system can be operated in a refueling mode (e.g., when a vehicle operator requests refueling from the fuel tank), where controller 212 can keep filter flush valve 261 closed while opening isolation valve 252 (if included) to depressurize the fuel tank, subsequently allowing refueling to proceed. Therefore, isolation valve 252 (if included) can be kept open during refueling operation to allow refueling fuel vapor to be stored in the filter canister. After refueling is complete, the isolation valve can be closed.

[0059] As another example, the fuel system can be operated in a filter canister flushing mode (e.g., after the emission control ignition temperature has been achieved and the engine is burning air and fuel), where controller 212 can open filter canister flushing valve 261 while closing isolation valve 252 (if included). In this document, fresh air can be drawn through ventilation line 227 and through fuel vapor filter canister 222 using a vacuum generated by the intake manifold of the operating engine to flush stored fuel vapor into intake manifold 244. In this mode, the flushed fuel vapor from the filter canister is burned in the engine. The flushing can continue until the amount of stored fuel vapor in the filter canister falls below a threshold.

[0060] Controller 212 may form part of control system 214. As discussed, in some examples, control system 214 may be integrated with... Figure 1 The control system 190 described herein is identical. Control system 214 is shown as receiving information from a plurality of sensors 216 (various examples of the plurality of sensors described herein) and sending control signals to a plurality of actuators 281 (various examples of the plurality of actuators described herein). As an example, sensors 216 may include an exhaust gas sensor 237, a temperature sensor 233, a pressure sensor 291, a pressure sensor 282, a filter canister temperature sensor 232, a MAF sensor 210, an intake air temperature (IAT) sensor 257, a pressure sensor 263, and a catalyst monitoring sensor (CMS) 298, also referred to as a post-catalyst oxygen sensor, located upstream of emission control device 270. Other sensors, such as pressure sensors, temperature sensors, air / fuel ratio sensors, and composition sensors, may be coupled to various locations within vehicle system 206. As another example, actuators may include a throttle valve 262, a fuel tank isolation valve 252, a filter canister flush valve 261, a filter canister vent valve 297, an electric heater actuator 256a, etc. The controller can receive input data from various sensors, process the input data, and trigger actuators in response to the processed input data based on instructions or code programmed therein corresponding to one or more routines. (This is in the context of...) Figure 6 Describe an exemplary control routine.

[0061] The exhaust gas sensor 237 may include a heated exhaust oxygen (HEGO) sensor. The HEGO sensor 237 may also include an HEGO heating element 237a under the control of a controller, and the HEGO heating element may be used to heat the HEGO sensor to raise its temperature to a desired operating temperature. Although not explicitly shown, the HEGO sensor 237 may include a temperature sensing element configured to determine the temperature of the HEGO sensor.

[0062] CMS 298 may include another heated exhaust oxygen sensor and may also include a CMS heating element 298a. The CMS heating element 298a may be under the control of a controller and may be used to heat CMS 298 to raise the temperature of the CMS to its desired operating temperature. Although not explicitly shown, CMS 298 may include a temperature sensing element configured to determine the temperature of the CMS.

[0063] In some examples, the exhaust system may include an exhaust tuning valve 299, which may be under the control of a controller and may be actuated to a fully open or fully closed position, or a position between fully open and fully closed.

[0064] As will be discussed in detail below, there is a possibility that one or more of the HEGO heating element 237a and / or CMS heating element 298a may deteriorate. In such cases, alternative methods may be needed to actively raise the temperature of the HEGO sensor 237 and / or CMS 298. This will be discussed in more detail below. Figure 6 Let's discuss this method in detail.

[0065] In some examples, the controller can be placed in a power reduction mode or a sleep mode, where it maintains only essential functions and operates with lower battery consumption than in the corresponding wake-up mode. For example, the controller can be placed in sleep mode after a vehicle shutdown event to perform diagnostic routines for a period of time after the event. The controller may have a wake-up input that allows it to return to wake-up mode based on input received from one or more sensors. For example, opening a vehicle door or a remote start event can trigger a return to wake-up mode. In some examples, wake-up capability allows circuitry to wake the controller to perform diagnostics on the engine system, as discussed in more detail below.

[0066] Controller 212 can intermittently perform an unwanted evaporative emission detection routine on fuel system 218 and / or evaporative emission system 251 to confirm that unwanted evaporative emissions are not present in said fuel system and / or evaporative emission system. Therefore, the evaporative emission detection routine can be performed using engine-off natural vacuum (EONV) and / or vacuum supplemented from a vacuum pump during engine shutdown (engine-off test), the EONV being generated due to temperature and pressure changes at the fuel tank after engine shutdown. Alternatively, the evaporative emission detection routine can be performed while the engine is running by operating a vacuum pump and / or using engine intake manifold vacuum. In some configurations, a filter canister vent valve (CVV) 297 can be connected within vent line 227. CVV 297 can be used to adjust the flow rate of air and vapor between filter canister 222 and the atmosphere. CVV can also be used for diagnostic routines. When the CVV is included, it can be opened during fuel vapor storage operations (e.g., during fuel tank refueling and when the engine is not running) to allow air stripped of fuel vapor after passing through the filter canister to be vented to the atmosphere. Similarly, during flushing operations (e.g., during filter canister regeneration and when the engine is running), the CVV can be opened to allow a flow of fresh air to remove fuel vapor stored in the filter canister. In some examples, CVV 297 can be a solenoid valve, wherein opening or closing of the valve is performed via actuation of the filter canister vent solenoid. Specifically, the filter canister vent valve can be an opening that closes when the filter canister vent solenoid is actuated. In some examples, CVV 297 can be configured as a latchable solenoid valve. In other words, when the valve is placed in the closed configuration, the valve latches closed without requiring additional current or voltage. For example, the valve can be closed using a 100ms pulse and subsequently opened using another 100ms pulse at a later time. In this way, the amount of battery power required to maintain the CVV closed is reduced.

[0067] The intake manifold 244 passes through a series of intake valves 253 and connects to the combustion chamber or cylinder 230. The combustion chamber is further connected to the exhaust manifold 248 via a series of exhaust valves 254. Although in Figure 2 Only one intake valve and one exhaust valve are depicted here, but it will be understood that each combustion chamber or cylinder may include both an intake valve and an exhaust valve. In the depicted embodiment, a single exhaust manifold 248 is shown. However, in other embodiments, the exhaust manifold may include multiple exhaust manifold sections. A configuration with multiple exhaust manifold sections allows outflows from different combustion chambers to be directed to different locations within the engine system.

[0068] In one embodiment, each of the exhaust valve and the intake valve may be electronically actuated or controlled. In another embodiment, each of the exhaust valve and the intake valve may be cam-actuated or controlled. Whether electronically or cam-actuated, the timing of the exhaust valve and the intake valve opening and closing can be adjusted as needed for desired combustion and emission control performance. Although the camshaft is not illustrated in this exemplary description, one or more camshaft sensors (not shown) may be included in the vehicle propulsion system. Additionally, the crankshaft 274 may include a crankshaft sensor 249. In some examples, the position of one or more pistons coupled to the engine cylinder 230 may be inferred using one or both of the crankshaft sensor 249 and / or the camshaft sensor (not shown).

[0069] In some examples, engine 110 may include a variable displacement engine (VDE), wherein each cylinder of engine 110 may be selectively deactivated, where deactivation means the ability of controller 212 to command the closing of the intake and exhaust valves for a particular cylinder, thereby sealing that particular cylinder. If fuel injection is also stopped, such an action can result in the particular cylinder essentially acting as an air spring while the engine is spinning. Therefore, as depicted herein, in one embodiment, the deactivation of intake valve 253 may be controlled by a first VDE actuator 276, while the deactivation of exhaust valve 254 may be controlled by a second VDE actuator 277. In alternative embodiments, a single VDE actuator may control the deactivation of both the intake and exhaust valves of the deactivated cylinder. In other embodiments, a single cylinder valve actuator can deactivate multiple cylinders (both intake and exhaust valves), for example, all cylinders in a deactivated group, or different actuators can control the deactivation of all intake valves of all deactivated cylinders in one group, while another different actuator controls the deactivation of all exhaust valves of all deactivated cylinders in the same group. It will be understood that if a cylinder is a non-deactivated cylinder of a VDE engine, then that cylinder may not have any valve deactivation actuator. It can be further understood that while engine 110 is depicted as a VDE engine, in other examples, the engine may not be a VDE engine without departing from the scope of this disclosure.

[0070] In some examples, vehicle system 206 may be a hybrid vehicle having multiple torque sources available for one or more vehicle wheels 236 (e.g., 130). In the illustrated example, vehicle system 206 includes an engine 110 and an electric motor 241. Electric motor 241 may be a motor (e.g., 120) or a motor / generator. The crankshaft 274 of engine 110 and electric motor 241 is connected to vehicle wheels 236 via transmission 243 when one or more clutches 246 are engaged. In the depicted example, a first clutch is provided between crankshaft 274 and electric motor 241, and a second clutch is provided between electric motor 241 and transmission 243. Controller 212 may send signals to actuators (not shown) of each clutch 246 to engage or disengage the clutch, thereby connecting or disconnecting the crankshaft from electric motor 241 and components connected to the motor, and / or connecting or disconnecting electric motor 241 from transmission 243 and components connected to the transmission. Transmission 243 may be a gearbox, a planetary gear system, or another type of transmission. The powertrain can be configured in various ways, including as a parallel, series, or series-parallel hybrid vehicle.

[0071] Motor 241 receives power from traction battery 247 (e.g., 150) to provide torque to vehicle wheels 130. Motor 241 can also operate as a generator, for example, during braking operations, to provide power to charge traction battery 247.

[0072] Turn now Figure 3 Another exemplary engine system 308 is shown. Without departing from the scope of this disclosure, an engine system 308 may be included in a vehicle propulsion system 206 (e.g., 100). It will be understood that the engine system 206 may also include many of the components of the engine system 308. An engine 310 (e.g., 110) includes an engine intake system 362 (e.g., 223) and an engine exhaust system 363 (e.g., 225). In one example, engine system 308 may be a diesel engine system. In another example, engine system 308 may be a gasoline engine system. In the depicted embodiment, engine 310 is a turbocharged engine coupled to a turbocharger 315, which includes a compressor 314 driven by a turbine 316. Specifically, fresh air is introduced into engine 310 via an air purifier 312 (e.g., 215) along an intake duct 342 (e.g., 242) and flows to compressor 314. The compressor can be any suitable intake compressor, such as a motor-driven or driveshaft-driven supercharger compressor. In engine 310, the compressor is a turbocharger compressor mechanically coupled to turbine 316 via shaft 319, turbine 316 being driven by expanding engine exhaust.

[0073] like Figure 3 As shown, compressor 314 is connected to throttle valve 320 (e.g., 262) via supercharged air cooler (CAC) 318. Throttle valve 320 is connected to engine intake manifold 322 (e.g., 244). Compressed air charges from the compressor through supercharged air cooler 318 and throttle valve 320 to reach intake manifold 322. Figure 3 In the embodiment shown, the pressure of the air charge within the intake manifold 322 is sensed via a manifold air pressure (MAP) sensor 324 (e.g., 213). In some examples, the airflow rate in the intake manifold may be sensed via a mass airflow (MAF) sensor 321 (e.g., 210). The temperature of the ambient air entering the intake duct 342 may be estimated via an intake air temperature (IAT) sensor 351 (e.g., 257).

[0074] One or more sensors may be coupled to the inlet of compressor 314. For example, temperature sensor 358 may be coupled to the inlet to estimate compressor inlet temperature, and pressure sensor 356 may be coupled to the inlet to estimate compressor inlet pressure. As another example, ambient humidity sensor 357 may be coupled to the inlet to estimate the humidity of the charge air entering the intake manifold. Other sensors may include, for example, an air-fuel ratio sensor. In other examples, one or more of the compressor inlet conditions (e.g., humidity, temperature, pressure, etc.) may be inferred based on engine operating conditions. Additionally, when exhaust gas recirculation (EGR) is enabled, the sensors may estimate temperature, pressure, humidity, and the air-fuel ratio of the charge mixture, which includes fresh air, recirculated compressed air, and residual exhaust gas received at the compressor inlet.

[0075] The wastegate actuator 392 can be actuated to open the wastegate 391, thereby pumping at least some exhaust pressure from upstream of the turbine to a location downstream of the turbine via the wastegate 391. By reducing the exhaust pressure upstream of the turbine, the turbine speed can be reduced, which in turn helps to reduce compressor surge. The wastegate 391 can be positioned in the wastegate passage 390. The methods discussed herein utilize a wastegate that can be actuated to open and close; however, it is recognized herein that in some examples, a spring-loaded wastegate may be included in the vehicle system.

[0076] To assist turbocharger 315, an additional electric intake compressor, also referred to herein as an electric compressor or electric supercharger 355, can be integrated into the vehicle propulsion system. Power can be supplied to electric supercharger 355 via an onboard energy storage device (e.g., 150), which may include batteries, capacitors, supercapacitors, etc. The electric supercharger may include a compressor driven by an electric motor. The operating speed of the electric supercharger may include adjusting the operating speed of the electric motor, which is operated via the onboard energy storage device (e.g., 150).

[0077] In one example, the electric supercharger 355 can be actuated in response to the demand for increased wheel torque, so as to quickly provide the desired boost air to the engine when the turbocharger turbocharges accelerate. Therefore, the increased torque can be met without inducing turbo lag, which would otherwise occur without the assistance of the electric supercharger. In this example, the electric supercharger 355 can be actuated to be turned off or deactivated in response to the turbocharger reaching a threshold speed (e.g., 70,000 rpm). More specifically, the operation control of the electric supercharger 355 can be implemented based on command signals (e.g., duty cycle or pulse width signal) received from a vehicle controller (e.g., controller 212). For example, the controller can send a signal to the electric supercharger actuator 355b, which can actuate to turn the electric supercharger on. In another example, the controller can send a signal to the electric supercharger actuator 355b, which can actuate to turn the electric supercharger off. In one example, the electric booster actuator may include an electric motor that drives the compression of air. In some examples, as will be discussed in detail below, the electric compressor may be rotated in the opposite direction. This may be at least partially via an H-bridge circuit (see [link to H-bridge circuit]). Figures 5A to 5B This enables the electric supercharger 355 to operate in reverse.

[0078] An electric supercharger 355 can be positioned between a first electric supercharger conduit 359a and a second electric supercharger conduit 359b. The first electric supercharger conduit 359a can fluidly connect the intake manifold 342 to the electric supercharger 355 upstream of the electric supercharger bypass valve 361. The second electric supercharger conduit 359b can fluidly connect the electric supercharger 355 to the intake manifold 342 downstream of the electric supercharger bypass valve 361. For example, air can be drawn into the electric supercharger 355 upstream of the electric supercharger bypass valve 361 via the first electric supercharger conduit 359a, and compressed air can exit the electric supercharger 355 and be delivered to the intake manifold 342 downstream of the electric supercharger bypass valve 361 via the second electric supercharger conduit. In this way, compressed air can be delivered to the engine intake manifold 322. It is understood that the above description relates to the operation of the electric compressor in the forward direction. In some examples, the electric compressor can be rotated in the opposite direction, which can therefore result in compressed air being delivered in the opposite direction, in other words, compressed air being delivered from the intake manifold (and in some examples the exhaust system) to the atmosphere via the intake duct 342.

[0079] In a scenario where the electric supercharger 355 is activated to provide boost more quickly than when relying solely on the turbocharger 315, it is understood that the electric supercharger bypass valve 361 can be commanded to close when the electric supercharger 355 is activated. In this way, intake air can flow through both the turbocharger 315 and the electric supercharger 355. Once the turbocharger reaches its threshold speed, the electric supercharger 355 can be deactivated, and the electric supercharger bypass valve 361 can be commanded to open.

[0080] Intake manifold 322 is connected to a series of combustion chambers 330 (e.g., 230) via a series of intake valves 353 (e.g., 253). The combustion chambers are further connected to exhaust manifold 336 (e.g., 248) via a series of exhaust valves 354 (e.g., 254). In the depicted embodiment, a single exhaust manifold 336 is shown. However, in other embodiments, the exhaust manifold may include multiple exhaust manifold sections. A configuration with multiple exhaust manifold sections allows effluent from different combustion chambers to be directed to different locations within the engine system.

[0081] As discussed above, in one embodiment, each of the exhaust valve and intake valve may be electronically actuated or controlled. In another embodiment, each of the exhaust valve and intake valve may be cam-actuated or controlled. Whether electronically actuated or cam-actuated, the timing of the exhaust valve and intake valve opening and closing can be adjusted as needed for desired combustion and emission control performance. Although the camshaft is not illustrated in this exemplary description, one or more camshaft sensors (not shown) may be included in the vehicle propulsion system. Furthermore, it is understood that vehicle system 308 may include crankshaft 374 (e.g., 274) and may include crankshaft sensors (e.g., 349). In some examples, the position of one or more pistons coupled to engine cylinder 330 (e.g., 230) may be inferred using one or both of the crankshaft sensor and / or camshaft sensor.

[0082] In some examples, engine 310 may include a variable displacement engine (VDE), wherein each cylinder of engine 310 may be selectively deactivated, where deactivation means the ability of controller 212 to command the closing of the intake and exhaust valves for a particular cylinder, thereby sealing that particular cylinder. If fuel injection is also stopped, such an action can result in the particular cylinder essentially acting as an air spring while the engine is spinning. Therefore, as depicted herein, in one embodiment, the deactivation of intake valve 353 may be controlled by a first VDE actuator 376 (e.g., 276), while the deactivation of exhaust valve 354 may be controlled by a second VDE actuator 377 (e.g., 277). In alternative embodiments, a single VDE actuator may control the deactivation of both the intake and exhaust valves of the deactivated cylinder. In other implementations, a single cylinder valve actuator can deactivate multiple cylinders (both intake and exhaust valves), for example, all cylinders in a deactivated bank, or different actuators can control the deactivation of all intake valves of all deactivated cylinders in one group, while another different actuator controls the deactivation of all exhaust valves of all deactivated cylinders in the same group. It will be understood that if the cylinder is a non-deactivated cylinder of a VDE engine, then the cylinder may not have any valve deactivation actuator.

[0083] One or more fuels, such as gasoline, ethanol blends, diesel, biodiesel, compressed natural gas, etc., can be supplied to the combustion chamber 330 via injector 366 (e.g., 266). Fuel can be supplied to the combustion chamber via direct injection, port injection, throttle body injection, or any combination thereof. Combustion in the combustion chamber can be initiated via spark ignition, laser ignition, and / or compression ignition.

[0084] like Figure 3As shown, exhaust gas from one or more exhaust manifold sections can be directed to turbine 316 to drive the turbine. The combined flow from the turbine and the exhaust valve then flows through emission control device 370 (e.g., 270). In one example, emission control device 370 may be an ignition catalyst. Generally, exhaust aftertreatment device 370 is configured to catalytically treat the exhaust stream and thereby reduce the amount of one or more substances in the exhaust stream. For example, exhaust aftertreatment device 370 may be configured to capture NOx from the exhaust stream when the exhaust stream is lean and reduce the captured NOx when the exhaust stream is rich. In other examples, exhaust aftertreatment device 370 may be configured to disproportionate NOx or selectively reduce NOx with the assistance of a reducing agent. In other examples, exhaust aftertreatment device 370 may be configured to oxidize residual hydrocarbons and / or carbon monoxide in the exhaust stream. Different exhaust aftertreatment catalysts with any of these functionalities may be disposed individually or together in the coating layer or elsewhere in the exhaust aftertreatment stage. In some embodiments, the exhaust aftertreatment stage may include a regenerable soot filter configured to capture and oxidize particulate matter in the exhaust stream. In some examples, the one or more emission control devices may include an electric heater 327 (e.g., 256) configured to raise the temperature of the emission control device to a desired operating temperature (e.g., ignition temperature). The electric heater may be controlled by a controller 212 that may send signals to an electric heater actuator 327a to actuate the electric heater to turn it on or off.

[0085] The engine exhaust system 363 may also include a gasoline particulate filter (GPF) 364 (e.g., 217). The GPF 364 may include a particulate filter, a hydrocarbon trap, a catalytic coating, or a combination thereof. In some examples, during operation of the engine 310, the GPF 364 may be periodically regenerated by operating at least one cylinder of the engine at a specific air-fuel ratio to increase the temperature of the GPF 364, such that retained hydrocarbons and soot particles can be oxidized.

[0086] In some examples, temperature sensor 367a (e.g., 226) can be located upstream of the inlet of GPF 364 and temperature sensor 367b (e.g., 229) can be located downstream of GPF 364. Temperature sensors 367a and 367b can be used to assess the temperature of GPF 364 for, for example, regeneration purposes. Furthermore, pressure sensor 365 (e.g., 263) can assess the pressure in the exhaust system. For example, pressure sensor 365 can be a differential pressure sensor located upstream (closer to the exhaust manifold) and downstream (further from the exhaust manifold) of GPF 364. Pressure sensor 365 can be used to determine the pressure at the inlet of GPF 364 to assess the operating conditions of the air to be introduced into GPF 364 for regeneration. Additionally, in some examples, a soot sensor can be located downstream of GPF 364 to assess the level of soot released from GPF 364. Although in Figure 3 While GPF is described herein, it is understood that in some examples, a diesel particulate filter (DPF) may be included in engine system 308 without departing from the scope of this disclosure.

[0087] In some examples, the exhaust system may include an exhaust tuning valve 399 (e.g., 299), which may be under the control of a controller and may be actuated to a fully open or fully closed position, or a position between fully open and fully closed.

[0088] An exhaust gas recirculation (EGR) delivery passage 380 may be coupled upstream of the turbine 316 to an exhaust passage 304 (e.g., 235) to provide high-pressure EGR (HP-EGR) to the engine intake manifold located downstream of the compressor 314. An EGR valve 352 may be coupled to the EGR passage 380 at the junction of the EGR passage 380 and the intake passage 342. The EGR valve 352 may be opened to allow a controlled amount of exhaust gas to the compressor outlet to achieve desired combustion and emission control performance. The EGR valve 352 may be configured as a continuously variable valve or an on / off valve. In other embodiments, the engine system may additionally or alternatively include a low-pressure EGR (LP-EGR) flow path, in which exhaust gas is drawn downstream of the turbine 316 and recirculated to the engine intake manifold located upstream of the compressor 314.

[0089] One or more sensors can be coupled to EGR channel 380 to provide details about the composition and conditions of the EGR. For example, a temperature sensor 368 can be provided to determine the temperature of the EGR, a pressure sensor 369 can be provided to determine the pressure of the EGR, a humidity sensor (not shown) can be provided to determine the humidity or moisture content of the EGR, and an air-fuel ratio sensor (not shown) can be provided to estimate the air-fuel ratio of the EGR. Alternatively, the EGR conditions can be inferred by one or more temperature, pressure, humidity, and air-fuel ratio sensors coupled to the compressor inlet.

[0090] Multiple sensors, including exhaust temperature sensor 328 (e.g., 233), exhaust sensor 326 (e.g., 237), and exhaust pressure sensor 329, can be coupled to the main exhaust duct 304. The exhaust sensors can be linear oxygen sensors or UEGO (universal or wide-range exhaust oxygen), two-state oxygen sensors or EGO, HEGO (heated EGO), NOx, HC, or CO sensors. A catalyst monitoring sensor (CMS) 398 (e.g., 298) can, in some examples, be coupled downstream of the emission control unit (e.g., 370) to the main exhaust duct 304. CMS 398 can also be referred to as a post-catalyst oxygen sensor.

[0091] Similar to the above text Figure 2 As discussed herein, exhaust gas sensor 326 may include a heated exhaust oxygen (HEGO) sensor. HEGO sensor 326 may also include an HEGO heating element 326a (e.g., 237a) under the control of a controller, and said HEGO heating element may be used to heat the HEGO sensor to raise its temperature to a desired operating temperature. HEGO sensor 326 may include a temperature sensing element (not shown) configured to indicate the temperature of the HEGO sensor.

[0092] CMS 398 may include another heated exhaust oxygen sensor and may also include a CMS heating element 398a (e.g., 298a). The CMS heating element 298a may be under the control of a controller and may be used to heat CMS 398 to raise the temperature of the CMS to its desired operating temperature. CMS 398 may include a temperature sensing element (not shown) configured to indicate the temperature of CMS 398.

[0093] As will be discussed in detail below, there is a possibility that one or more of the HEGO heating element 326a and / or CMS heating element 398a may deteriorate. In such cases, alternative methods may be needed to actively raise the temperature of the HEGO sensor 326 and / or CMS 398. This will be discussed further below. Figure 6 Let's discuss this method in detail.

[0094] Engine system 308 may also include control system 214 as discussed above. Control system 214 is shown as receiving information from a plurality of sensors 216 (various examples of the plurality of sensors described herein) and sending control signals to a plurality of actuators 281 (various examples of the plurality of actuators described herein). As an example, sensors 216 may include exhaust gas sensor 326, CMS 398, MAP sensor 324, exhaust gas temperature sensor 328, exhaust gas pressure sensor 329, compressor inlet temperature sensor 358, compressor inlet pressure sensor 356, ambient humidity sensor 357, IAT sensor 351, engine coolant temperature sensor, etc., located upstream of turbine 316. Other sensors, such as additional pressure sensors, temperature sensors, air / fuel ratio sensors, and composition sensors, may be coupled to various locations within engine system 308.

[0095] Actuator 281 may include, for example, an electric supercharger bypass valve 361, a throttle valve 320, an electric supercharger actuator 355b, an EGR valve 352, a wastegate actuator 392, a HEGO heating element 326a, a CMS heating element 398a, and a fuel injector 366. Control system 214 may include controller 212. Controller 212 may receive input data from various sensors, process the input data, and trigger various actuators in response to the processed input data based on instructions or codes programmed therein corresponding to one or more routines.

[0096] Furthermore, similar to engine system 208, engine system 308 can be a hybrid vehicle having multiple torque sources available for one or more vehicle wheels 130. For example, vehicle system 308 may include an electric motor 341 (e.g., 241), also referred to as a motor or motor / generator. A crankshaft 374 (e.g., 274) may connect engine 310 (e.g., 110) and the electric motor to the wheels 130 via a transmission 343 (e.g., 243) when one or more clutches 346 (e.g., 246) are engaged. Electric motor 341 (e.g., 241 or 120) may receive power from a traction battery 347 (e.g., 247 or 150) as discussed above. Crankshaft 374 may include a crankshaft sensor 349 (e.g., 249).

[0097] Furthermore, engine system 308 can be connected to evaporative emission system (in) via filter flush valve (CPV) 394 (e.g., 261). Figure 3 Not shown, but see Figure 2 (of 251). Although in Figure 3The details of the evaporative emission system and fuel system are not specified, but it is understood that the components of such systems are similar to those described above. Figure 2 The parts depicted are the same.

[0098] Figure 4 Depicting can be done Figure 1 An exemplary embodiment of the combustion chamber or cylinder included in the engine 110 depicted herein. The cylinder (i.e., combustion chamber) 430 (e.g., 230, 330) may include a combustion chamber wall 436 and a piston 438 positioned therein. The piston 438 may include one or more piston rings 468. The one or more piston rings 468 may be used, for example, to seal the cylinder 430, assist piston heat transfer, and regulate fuel consumption. The piston 438 may be coupled to a crankshaft 474 (e.g., 274, 374) such that the reciprocating motion of the piston is converted into the rotational motion of the crankshaft. The crankshaft 474 may be coupled to at least one drive wheel of a passenger vehicle via a transmission system. Furthermore, a starter motor or electric motor (e.g., 120) may be coupled to the crankshaft 474 via a flywheel to enable starting operation of the engine 110 and / or to rotate the engine in an unfueled mode.

[0099] Cylinder 430 may receive intake air via intake passage 444 (e.g., 242, 342), which may be one of a plurality of intake passages connected to cylinder 430. Intake passage 444 may communicate with other cylinders of engine 110 besides cylinder 430. In some embodiments, one or more of the intake passages may include a supercharging device, such as a turbocharger or supercharger. Exhaust passage 448 (e.g., 235, 304) may receive exhaust air from cylinder 430 and other cylinders of engine 110.

[0100] Each cylinder of engine 110 may include one or more intake valves and one or more exhaust valves. For example, cylinder 430 is shown as including at least one intake lift valve 456 (e.g., 253, 353) and at least one exhaust lift valve 450 (e.g., 254, 354) located in the upper region of cylinder 430. In some embodiments, each cylinder of engine 110, including cylinder 430, may include at least two intake lift valves and at least two exhaust lift valves located in the upper region of said cylinder.

[0101] Intake valve 456 can be controlled by a controller via actuator 452. Similarly, exhaust valve 450 can be controlled by a controller via actuator 454. Under certain conditions, the controller can change the signals provided to actuators 452 and 454, thereby controlling the opening and closing of the corresponding intake and exhaust valves. The positions of intake valve 456 and exhaust valve 450 can be determined by corresponding position sensors 499a and 499b, respectively. The valve actuators can be of the electric valve actuation type or the cam actuation type, or a combination thereof. Intake valve timing and exhaust valve timing can be controlled simultaneously, or any of the following possibilities can be used: variable intake cam timing, variable exhaust cam timing, dual independent variable cam timing (TiVCT), or fixed cam timing. Each cam actuation system may include one or more cams (e.g., actuators 452 and / or 454) and may utilize one or more of a cam profile changing (CPS) system, a variable cam timing (VCT) system, a variable valve timing (VVT) system, and / or a variable valve lift (VVL) system, the controller of which can operate the system to change valve operation. For example, cylinder 430 may alternatively include an intake valve controlled via electric valve actuation and an exhaust valve controlled via cam actuation including CPS and / or VCT. In other embodiments, the intake and exhaust valves may be controlled by a common valve actuator or actuation system or a variable valve timing actuator or actuation system.

[0102] exist Figure 4 The example shown here for illustrative purposes is a TiVCT. Specifically, intake camshaft 481 and exhaust camshaft 482 are illustrated. It will be understood that this configuration allows for the independent advance or retardation of the timing of both intake camshaft 481 and exhaust camshaft 482. This capability allows for increased power and torque, especially at lower engine speeds (engine RPM), as well as improved fuel economy and reduced emissions. This capability can further enable precise control of the intake and exhaust valve positions, which in some examples may include positioning a specific cylinder with both the intake and exhaust valves at least partially open.

[0103] In the example, a first hydraulically controlled actuator 483, under the control of a controller, can adjust the rotation of the intake camshaft 481, and a second hydraulically controlled actuator 484 can adjust the rotation of the second camshaft 482. In this way, the first and second hydraulically controlled actuators can control the camshafts based on operating conditions to advance or delay engine timing. For example, the controller can use crankshaft position sensors 497 (e.g., 249, 349) and position sensors 499a and 499b to determine engine timing.

[0104] Although this article is Figure 4The examples depicted here illustrate camshaft actuators (e.g., 483 and 484) as being hydraulically controlled, but there may be some examples in which cam torque actuation (CTA) can be used instead of hydraulically driven cam phasing, which can utilize existing torsional energy in the valve mechanism to rotate the camshaft, as is generally understood in the art.

[0105] Furthermore, it is understood that in examples where the vehicle includes a TiVCT, the EGR valve (e.g., 152) and EGR passage 380 may not be included in the vehicle system, since delaying exhaust cam timing can achieve a similar result to exhaust recirculation.

[0106] In addition, although Figure 4 Examples of TiVCT engines are described above, but in other examples, the engine may include a variable displacement engine (VDE).

[0107] Cylinder 430 may have a compression ratio, which is the ratio of the volume within the cylinder when piston 438 is at bottom dead center (BDC) to that at top dead center (TDC). It is understood that, as discussed herein, BDC may include the position of piston 438 closest to crankshaft 474, while TDC may include the position of piston 438 furthest from crankshaft 474. Furthermore, it is understood that, as discussed herein, TDC can be understood as being 180° away from BDC. Typically, the compression ratio is in the range of 9:1 to 10:1. However, in some examples where different fuels are used, the compression ratio may be increased. This may occur, for example, when using higher octane fuels or fuels with higher enthalpy of vaporization. If direct injection is used, the compression ratio may also be increased due to the effect of direct injection on engine knock.

[0108] In some embodiments, each cylinder of engine 110 may include a spark plug (not shown) for initiating combustion. An ignition system (not shown) may provide an ignition spark to cylinder 430 via the spark plug (not shown) in response to a spark advance signal from a controller in a selected operating mode. However, in some embodiments, such as where engine 110 can be initiated by automatic ignition or by fuel injection (which may be the case for some diesel engines), the spark plug may be omitted. In other embodiments, a laser ignition device 492, also referred to herein simply as laser 492, may be included in engine 110 and may be configured to ignite a mixture of fuel and oxidizer, similar to the function provided via the spark plug.

[0109] In some embodiments, each cylinder of engine 110 may be configured with one or more fuel injectors for supplying fuel thereto. As a non-limiting example, cylinder 430 may include two fuel injectors (e.g., a port fuel injector and a direct fuel injector). Fuel injector 466 (e.g., 266, 366) is shown directly coupled to cylinder 430 to directly inject fuel into said cylinder in proportion to the pulse width of a signal received from a controller via an electronic actuator. In this manner, fuel injector 466 provides what is considered a fuel injector that directly injects fuel (hereinafter referred to as "DI") into cylinder 430. Although Figure 4 Injector 466 is shown as a side injector, but it can also be located on top of the piston, for example, near the spark plug (not shown) or the laser ignition device 492. When operating the engine with alcohol-based fuels, such a location can improve mixing and combustion due to the lower volatility of some alcohol-based fuels. Alternatively, the injector can be positioned above and near the intake valve head to improve mixing. Fuel can be delivered to the fuel injector 466 from a high-pressure fuel system that includes a fuel tank, fuel pump, fuel rail, etc. Alternatively, fuel can be delivered at lower pressures by a single-stage fuel pump, in which case the timing of direct fuel injection may be more limited during the compression stroke than when using a high-pressure fuel system.

[0110] Fuel can be delivered to the cylinder during a single cycle. As discussed herein, a single engine cycle includes the exhaust stroke, intake stroke, compression stroke, and power stroke. It can be further understood that when the piston is within the TDC threshold (e.g., within 5°) between the exhaust and intake strokes, the intake and exhaust valves can be at least partially open. Directly injected fuel can be delivered during the intake stroke and partially during the preceding exhaust stroke. Furthermore, the directly injected fuel can be delivered as a single injection or multiple injections. These can include multiple injections during the compression stroke, multiple injections during the intake stroke, or a combination of some direct injections during the compression stroke and some direct injections during the intake stroke. When multiple direct injections are performed, the relative distribution of the total guided injected fuel between the intake stroke (direct) injection and the compression stroke (direct) injection can be referred to as the second injection ratio. For example, injecting a larger amount of directly injected fuel for the combustion event during the intake stroke could be an example of a higher second ratio of intake stroke direct injection, while injecting a larger amount of said fuel for the combustion event during the compression stroke could be an example of a lower second ratio of intake stroke direct injection. It should be noted that these are merely examples of different injection ratios, and various other injection ratios can be used.

[0111] A crankcase forced ventilation (PCV) system may be coupled to the engine intake port to allow gases in the crankcase 462 to be discharged in a controlled manner. The engine 110 may include a crankcase ventilation duct 458 and a PCV line 460 to discharge gases from the crankcase 462 and into the intake manifold. In some examples, the PCV line 460 may include a PCV valve 464, which may be an electronically controlled valve (e.g., a powertrain control module (PCM) control valve), wherein the controller may command a signal to change the valve position from an open position (or a high-flow position) to a closed position (or a low-flow position) or vice versa, or any position in between.

[0112] As described above, Figure 4 Only one cylinder of a multi-cylinder engine is shown. Therefore, each cylinder can similarly include its own set of intake / exhaust valves, fuel injectors, spark plugs, laser ignition devices, piston rings, etc.

[0113] Figure 5A and Figure 5B An exemplary circuit 500 is shown that can be used to reverse the rotational orientation of an electric motor (e.g., 120). Such circuitry can be used to rotate an engine (e.g., 110) in a forward (e.g., the same direction as when the engine operates to burn air and fuel) or in a reverse direction, and / or to rotate an electric compressor (e.g., 355) in a forward (e.g., where compressed air is delivered to the engine and exhaust system) or in a reverse direction. Therefore, circuit 500 schematically depicts an H-bridge circuit that can be used to operate a motor 510 (e.g., 120 and / or 241, 341) in a first (forward) direction and alternatively in a second (reverse) direction. Circuit 500 includes a first (LO) side 520 and a second (HI) side 530. Side 520 includes transistors 521 and 522, while side 530 includes transistors 531 and 532. Circuit 500 also includes a power supply 540.

[0114] exist Figure 5AIn this configuration, transistors 521 and 532 are activated (excited), while transistors 522 and 531 are deactivated. In this configuration, the left lead 551 of motor 510 is connected to power supply 540, and the right lead 552 of motor 510 is grounded. In this way, motor 510 can operate in the forward (or default) direction. When the engine is operated in the forward direction via the motor, the engine can be in a rotation-start mode where initial combustion begins. Additionally and / or alternatively, when the engine is operated in the forward direction via the motor, the engine (and the motor or another motor) can be in a drive mode for driving the vehicle. It is understood that in some examples, the engine can be rotated in the forward (e.g., default) direction without fuel and without combustion, while in other examples, the engine can be rotated in the reverse direction without fuel and without combustion. Similarly, in some examples, the electric compressor can be rotated or turned in the forward direction, while in other examples, the engine can be rotated in the reverse direction.

[0115] exist Figure 5B In this configuration, transistors 522 and 531 are activated (energized), while transistors 521 and 532 are deactivated. In this configuration, the right lead 552 of motor 510 is connected to power supply 540, and the left lead 551 of motor 510 is grounded. In this way, motor 510 can run in the reverse direction.

[0116] The above text is about Figures 1 to 5B The described system enables a system for a hybrid vehicle, comprising a controller having computer-readable instructions stored in a non-transitory memory. These instructions, when executed, can cause the controller to activate a heat source and actively transfer heat from the heat source to the heated exhaust oxygen sensor under engine start-up conditions, provided the heating element of the heated exhaust oxygen sensor has deteriorated. This action can be used to increase the temperature of the heated exhaust oxygen sensor to its desired operating temperature, wherein actively transferring heat from the heat source to the heated exhaust oxygen sensor includes rotating the engine in a forward or reverse direction via a motor, depending on the location of the heated exhaust oxygen sensor with its deteriorated heating element and the heat source, without fuel being added.

[0117] In one example of such a system, the electric heating source also includes a heater connected to an emission control device located in the exhaust system of the engine, or one or more laser ignition devices configured to provide laser ignition energy to one or more cylinders of the engine.

[0118] Such systems may also include an intake throttle valve positioned in the engine's intake port and an exhaust tuning valve positioned in the engine's exhaust system. In this example, the controller may store additional instructions for controlling the position of one or more of the throttle valve and / or exhaust tuning valve such that heat from an electrothermal source is trapped near the heated exhaust oxygen sensor while preventing undesirable pressure build-up in the engine. The vicinity of the heated exhaust oxygen sensor may include an area or space near the heated exhaust oxygen sensor (e.g., within a threshold distance), where heat from the electrothermal source can easily raise the temperature of the heated exhaust oxygen sensor within a threshold time duration. This threshold time duration may be correlated with a specific engine start-up event. For example, the threshold time duration may include a desired amount of time for the sensor to reach its desired operating temperature, allowing engine fuel injection control to enter closed-loop control.

[0119] In some examples of such systems, the system may also include an electric supercharger positioned in the engine's air intake. In this example, the controller may store additional instructions for selecting to utilize the electric supercharger, which rotates via a motor in either a forward or reverse direction, instead of the engine, to actively deliver heat from a heat source to a heated exhaust oxygen sensor. Now turn to Figure 6 This diagram illustrates a high-level flowchart of an exemplary method 600 for actively raising the temperature of the HEGO based on current vehicle operating conditions. More specifically, method 600 can be used to actively raise the temperature of an HEGO (e.g., 237, 326) located upstream of an emission control device (e.g., 270, 370), or the HEGO may include a CMS (or post-catalytic converter oxygen sensor) (e.g., 298, 398) located downstream of the emission control device. Actively raising the temperature of the HEGO or CMS can be in response to an indication that the HEGO heating element (e.g., 237a, 326a) or CMS heating element (e.g., 298a, 398a) has deteriorated or is otherwise not operating as expected. Reference will be made to the methods described herein and... Figures 1 to 5B The system illustrated herein is used to describe method 600, but it will be understood that similar methods can be applied to other systems without departing from the scope of this disclosure. Instructions for implementing method 600 and the remainder of the methods included herein can be provided by a controller (e.g., Figures 2 to 3 The controller 212) executes based on instructions stored in a non-transitory memory and in conjunction with signals received from sensors in the engine system, such as those in… Figures 1 to 4The temperature sensor, pressure sensor, and other sensors described herein. The controller may employ actuators, such as motors / generators (e.g., 120), throttle valves (e.g., 262, 320), VDE actuators (e.g., 276, 277, 376, 377), electric superchargers (e.g., 355), EGR valves (e.g., 352), wastegate actuators (e.g., 392), laser ignition devices (e.g., 492), etc., according to the methods described herein.

[0120] Method 600 begins at 605 and may include assessing the current vehicle operating condition. The operating condition may be estimated, measured, and / or inferred, and said operating condition may include: one or more vehicle conditions, such as vehicle speed, battery state of charge, etc.; various engine conditions, such as engine status (on or off), engine load, engine temperature, engine speed, torque demand, exhaust air-fuel ratio, etc.; various fuel system conditions, such as fuel level, fuel type, fuel temperature, etc.; various evaporative emission system conditions, such as fuel vapor filter load, fuel tank pressure, etc.; and various environmental conditions, such as ambient temperature, humidity, air pressure, etc.

[0121] Moving to 610, method 600 may include an indication of whether conditions for actively heating a heated exhaust oxygen sensor are met, wherein the heated exhaust oxygen sensor may include an HEGO located upstream of the emission control device or a CMS located downstream of the emission control device. As an example, meeting the conditions at 610 may include an indication that a HEGO heating element (e.g., 237a, 326a) configured to heat the HEGO and located upstream of the emission control device has deteriorated or otherwise not functioning as expected or anticipated. In another example, meeting the conditions at 610 may include an indication that a CMS heating element (e.g., 298a, 398a) configured to heat the CMS and located downstream of the emission control device has deteriorated or otherwise not functioning as expected or anticipated. Meeting the conditions at 610 may, in some examples, additionally include an indication of a cold start event (e.g., a request to start the engine after a prolonged period of vehicle wet operation (e.g., more than six hours)) in which the HEGO heating element or the CMS heating element has not functioned as expected. In another example, fulfilling the condition at 610 may include an indication that the vehicle is in the process of an S / S event, wherein the temperature of the HEGO sensor located upstream of the emission control unit or the temperature of the CMS located downstream of the emission control unit drops below a threshold temperature while the engine is not burning air and fuel. Fulfilling the condition at 610 may also include an indication that the laser ignition device (e.g., 492) is expected to operate. Fulfilling the condition at 610 in some examples may include an indication that the VDE actuator is expected to operate. Fulfilling the condition at 610 in some examples may include an indication that the EGR valve, exhaust valve, throttle valve, electric supercharger bypass valve, etc., are expected to operate. Fulfilling the condition at 610 in some examples may include an indication that the electric heater (e.g., 256a, 327a) configured to heat the emission control unit is expected to operate. Fulfilling the condition at 610 in some examples may include an indication that the electric supercharger is expected to operate. Fulfilling the condition at 610 in some examples may include an indication that the electric motor configured to rotate the engine and / or the electric supercharger is expected to operate.

[0122] If at 610 the indication is not met for actively heating the HEGO sensor located upstream of the emission control unit or actively heating the CMS located downstream of the emission control unit, then method 600 may proceed to 615. At 615, method 600 may include maintaining current vehicle operating parameters. For example, the current operating state of the engine, electric motor, various valves, electric supercharger, etc., may be maintained. Method 600 may then terminate.

[0123] Returning to 610, in response to indication that a condition is met for actively heating the HEGO sensor located upstream of the emission control device or the CMS located downstream of the emission control device, method 600 may proceed to 620. At 620, method 600 may include a method for selecting either the HEGO sensor located upstream of the emission control device or the CMS located downstream of the emission control device. Such a selection may be made via a controller, and the selection may be based on several relevant current vehicle operating parameters.

[0124] As a first example, in response to an indication of an S / S event where the temperature of the HEGO sensor located upstream of the emission control unit drops below a threshold temperature or a desired operating temperature when the engine is not burning, and indicating that the heating element configured to heat the HEGO sensor has deteriorated, the following method can be selected. Specifically, a heater (e.g., 256, 327) configured to heat the emission control unit can be activated, and the engine can be reverse-rotated via a motor (e.g., 120) without fuel to direct heat from the emission control unit to the HEGO sensor located upstream of the emission control unit. In this example, the throttle (e.g., 262) can be commanded to at least a partially open position to relieve pressure in the engine intake caused by reversing the engine without fuel. However, the throttle may not be commanded to fully open, allowing heat to be trapped near the HEGO sensor. For example, such a method can be used when the vehicle's engine system is not equipped with, for example, an electric supercharger, or when the battery's state of charge is greater than a predetermined state of charge (where running the engine without fuel may not adversely affect downstream applications that may rely on battery power). The method described above with respect to the first example can be executed when the emission control device is above its desired operating temperature when the HEGO sensor drops below its desired operating temperature, or it can be used in a similar manner in examples where the emission control device has already dropped below its desired operating temperature.

[0125] Therefore, as a second example, in response to an indication of an S / S event where the temperature of the HEGO sensor located upstream of the emission control unit drops below a threshold temperature or desired operating temperature when the engine is not burning, and indicating that the heating element configured to heat the HEGO sensor has deteriorated, the following method can be selected. Specifically, the heater configured to heat the emission control unit (e.g., 256, 327) can be activated, and instead of reversing the engine when no fuel is being added, the electric supercharger (e.g., 355) can be reversed to direct heat from the emission control unit to the HEGO sensor located upstream of the emission control unit. In this example, the EGR valve (e.g., 352) and the exhaust valve (e.g., 391) can each be commanded to fully open, and the throttle valve can be commanded to open at least partially, or in another example, the throttle valve can be commanded to fully open. In this example, the electric supercharger bypass valve can be commanded or kept closed. Furthermore, in this example, if the engine includes a VDE engine, the engine cylinders can be commanded to seal, thereby directing fluid flow around the restricted engine. Such actions can reduce the amount of battery power required to draw heated air from the emission control unit to a HEGO sensor located upstream of the emission control unit. This method can be used, for example, in vehicles where the engine includes an electric supercharger, and / or in response to a battery state of charge (SOC) less than the predetermined SOC discussed in the first example above. In other words, such a method can utilize less battery power than methods that reverse the rotation of a large mass of the engine without fuel, and therefore, utilizing such a method can be desirable when battery power is limited.

[0126] As a variation of the second example utilizing an electric supercharger, where the engine is not sealed and fluid flow is transported around the engine, in another example, the engine can be positioned such that one or more engine cylinders are configured with at least partially open intake and exhaust valves. In this example, the exhaust valve can also be commanded to open fully, but the EGR valve can be commanded or maintained closed (the throttle valve can still be commanded to open at least partially or fully, and the electric supercharger bypass valve can be commanded or maintained closed). Such examples can include those where the engine includes a TiVCT engine, as discussed in [reference to...]. Figure 4As discussed above. For example, the engine can be briefly run without fuel until it is positioned such that at least one cylinder has both an open intake valve and an open exhaust valve. In this way, a path for fluid flow through the engine can be created. It is understood that in some examples, the engine may not include a TiVCT engine, and by running the engine without fuel, the intake and exhaust valves can be controlled to be at least partially open. The method discussed above with respect to the second example can be performed when the emission control device is above its desired operating temperature while the HEGO sensor has dropped below it, or in a similar manner in examples where the emission control device has already dropped below its desired operating temperature.

[0127] As a third example, in response to an S / S event indicating that the temperature of the HEGO sensor located upstream of the emission control device drops below a threshold temperature or desired operating temperature when the engine is not burning, and indicating that the heating element configured to heat the HEGO sensor has deteriorated, the following method can be selected. Specifically, in the case where the engine includes a laser ignition device (e.g., 492) for initiating combustion in the engine cylinders, one or more laser ignition devices can be activated without supplying fuel to the cylinder that ignites its laser. The cylinder whose laser is activated can be selected based on the fact that both the intake and exhaust valves of the cylinder are closed, while in other examples, in the case of a VDE engine, the desired cylinder whose laser is activated can be actively sealed, or the engine can be first rotated (in some examples, in conjunction with TiVCT control) to a position where one or more cylinders are sealed. By sealing the cylinder that supplies its laser energy via the laser ignition device, the heat generated according to the laser activation can be stored in the engine cylinder. More specifically, the laser energy can be concentrated on the piston of the selected cylinder, which can generate heat due to the laser beam striking the metal piston.

[0128] In this third example, the laser can be activated for a predetermined time period while the corresponding cylinder is sealed, and the engine cylinder with the captured heat can then be unsealed. In one example, unsealing the cylinder with the captured heat may include rotating the engine in the forward or default direction without fuel via a motor (e.g., 120) to direct the captured heat to an HEGO sensor located upstream of the emission control unit, thereby raising the HEGO sensor temperature to its desired operating temperature. In this example, the laser can be commanded to turn off, or the laser can be kept on, or the laser can be kept activated. Furthermore, in this example, the throttle valve can be commanded to open at least partially, and if the engine includes an electric supercharger bypass valve, the electric supercharger bypass valve can be commanded or kept open. Additionally, the wastegate valve can be commanded to open (e.g., fully open), and the EGR valve can be commanded to close (e.g., fully close).

[0129] In another exemplary variation of the third example, without rotating the engine in the forward direction without fuel, the engine cylinders with trapped heat can be opened, allowing the cylinders with trapped heat to be configured with intake and exhaust valves positioned at least partially open. An electric supercharger can be activated to rotate in the forward direction, directing compressed air to the engine, which in turn forces the heated air to the HEGO sensor located upstream of the emission control unit. The third example can be selected, for example, based on an engine system with a laser ignition device, and in one example, it can be selected if the emission control unit has not yet dropped below its desired operating temperature during an S / S event when the engine is not burning air and fuel. More specifically, the heat generated by activating the laser ignition device can be used to heat the HEGO sensor and can also be used to maintain the temperature of the emission control unit at or above its desired operating temperature.

[0130] Alternatively, in another example, the third method can be utilized if the temperature of the emission control unit drops below its desired operating temperature during an S / S event. In this example, the heat generated by the laser can be used to raise the temperature of the emission control unit to a temperature at or above its desired operating temperature. In another example where the emission control unit drops below its desired operating temperature, a strategy of using a laser ignition device to heat the HEGO sensor located upstream of the emission control unit can be used, and additionally, an electric heater associated with the emission control unit can be activated to raise the temperature of the emission control unit to or above its desired operating temperature. It is understood that for the third example of activating the electric supercharger in the positive direction to transport the captured heat from the engine cylinders to the HEGO located upstream of the emission control unit, the EGR valve can be commanded / maintained closed, the electric supercharger bypass valve can be commanded / maintained closed, and the throttle valve can be commanded to at least partially open (or fully open in some examples) configuration.

[0131] In any of the above descriptions of the third example in which the trapped in-cylinder heat is directed from the engine to the exhaust system of a vehicle equipped with an exhaust tuning valve (e.g., 299, 399) under the control of the vehicle controller, such an exhaust tuning valve can be commanded to at least partially closed, such that the heat used to raise the temperature of the HEGO sensor is trapped near the HEGO sensor. In one example, the exhaust tuning valve can be commanded to be completely or fully closed for a predetermined or determined time period, the time period varying with the pressure accumulating in the exhaust system due to the transport of heat from the cylinder to the exhaust system. For example, if the pressure in the exhaust system is maintained below a predetermined pressure, then only the exhaust tuning valve can be kept closed, and the pressure can be inferred from the time it takes to transport heat from the cylinder to the exhaust system or can be measured.

[0132] In some examples, the third example can be performed during a cold start event, where it is indicated that the heating element configured to heat the HEGO sensor has deteriorated, and where the heating element and sensor are positioned upstream or downstream of the emission control device. More specifically, during a cold start event, one or more cylinders of the engine can be sealed, and then one or more laser ignition devices can be activated to generate in-cylinder heat. The heated gas in the cylinder can then be transferred to the HEGO sensor positioned upstream or downstream of the emission control device by opening the engine cylinder and rotating the engine in the forward direction, or by opening the cylinder that generates in-cylinder heat, and subsequently transferred from the cylinder to the HEGO sensor positioned upstream or downstream of the emission control device by rotating an electric supercharger positioned in the engine intake in the forward direction. In this case using an electric supercharger, in order to effectively transfer in-cylinder heat to the sensor, such a method may include positioning the intake and exhaust valves coupled to any cylinder that has received laser ignition energy in a configuration that is at least partially open. In one example, at least a partially open configuration may include a location where an electric supercharger can efficiently deliver fluid flow through engine cylinders that have received laser ignition energy to transport heated gas to the sensor. Furthermore, in some examples, where the sensor is located either upstream or downstream of the emission control unit, a heater configured to raise the temperature of the emission control unit may be additionally activated during a cold start event.

[0133] As a fourth example, in response to a cold start event in which the temperature of the HEGO sensor located upstream of the emission control device is below a threshold temperature or a desired operating temperature, and indicating that the heating element configured to heat the HEGO sensor has deteriorated, the following method can be selected. Specifically, during a cold start, it may be necessary to rapidly raise the temperature of the emission control device to its desired operating temperature (e.g., ignition temperature), and an electric heater (e.g., 256, 327) coupled to the emission control device can be activated. To raise the temperature of the HEGO sensor located upstream of the emission control device to its desired operating temperature, the engine can be reversed via a motor without fuel to draw at least a portion of the heat from the emission control device to the HEGO sensor. In this example, the speed of the engine's reverse rotation and the heat supplied to the emission control device can be controlled to raise the temperature of the HEGO sensor to its desired operating temperature, while also raising the temperature of the emission control device to its desired operating temperature. In this example, the throttle valve can be commanded to open at least partially, and the exhaust valve can be commanded to open fully (if included). The EGR valve (if included) can be kept closed, and the electric supercharger bypass valve (if included) can be commanded to open fully. Such examples may include vehicles that do not include an electric supercharger, and may include situations where a laser ignition system is not provided to initiate combustion in the engine cylinders. Such examples may additionally or alternatively include an indication that the battery state of charge is greater than a predetermined battery state of charge (where reversing the engine without refueling may not adversely affect downstream applications that may rely on battery power).

[0134] In a variation of the fourth example, instead of rotating the engine in reverse without fuel, if the engine system includes an electric supercharger, the electric supercharger can be activated in reverse to draw heat from the emission control unit (heated via an electric heater coupled to the emission control unit) to a HEGO sensor located upstream of the emission control unit. More specifically, in this example, the throttle valve can be commanded to open at least partially or fully, the electric supercharger bypass valve can be commanded or maintained closed, and the engine cylinders can be commanded to be sealed (e.g., for a variable displacement engine), while the EGR valve and exhaust valve are commanded to open fully. Alternatively, without sealing the engine cylinders, the engine can be controlled to position at least one engine cylinder such that its intake and exhaust valves are at least partially open, thereby creating a path for fluid flow through the engine. In this example, the EGR valve can be commanded or maintained closed, but the exhaust valve can be commanded to open fully. The electric supercharger bypass valve can be commanded or maintained closed, and the throttle valve can be commanded to open at least partially or, in some examples, fully.

[0135] In another variation of the fourth example, an electric heater coupled to the emission control unit can be used to raise the temperature of the emission control unit. However, instead of reversing engine rotation or operating the electric supercharger to draw heat from the emission control unit to the HEGO sensor located upstream of the emission control unit, a laser ignition device can be used to generate in-cylinder heat, as discussed above, and this heat can then be transported to the HEGO sensor to raise its temperature to its desired operating temperature. Similar to what has been described above, one or more cylinders can be controlled for sealing, thus activating the laser ignition device coupled to one or more cylinders, resulting in heat generation in the selected one or more cylinders. After generating heat for a predetermined time in this manner, the engine can be rotated in the forward direction without fuel to direct the captured in-cylinder heat to the HEGO sensor located upstream of the emission control unit. Alternatively, a specific cylinder can be commanded to open (e.g., for a variable displacement engine) or otherwise controlled (e.g., via engine rotation without fuel) such that the intake and exhaust valves of the selected cylinder are at least partially open, and the electric supercharger can be activated in the forward direction to direct the captured in-cylinder heat to the HEGO sensor located upstream of the emission control unit. In such examples utilizing laser ignition devices, it is understood that the EGR valve can be commanded or maintained closed (if included), the wastegate valve can be commanded or maintained open (if included), the electric bypass valve can be commanded or maintained closed, and the throttle valve can be commanded to open at least partially or, in some examples, fully.

[0136] Furthermore, it can be understood that heat from the laser ignition device can additionally add heat to the emission control unit when used to raise the temperature of the HEGO sensor located upstream of the emission control unit. Therefore, such action can be advantageous because less total heat may be needed via an electric heater connected to the emission control unit, as some of the heat used to raise the temperature of the emission control unit can be provided via the captured in-cylinder heat. In some examples, the different variations of the fourth example can be selected based on the current state of charge of the energy storage device. For example, the controller may select which variation of the fourth example to utilize based on whether the state of charge is above or below a predetermined threshold.

[0137] As mentioned above Figures 2 to 3As discussed, in some examples, a CMS (e.g., 298, 398) or a post-catalytic converter oxygen sensor may be located downstream of the emission control unit. Such a CMS may have a heating element (e.g., 256a, 398a), and such heating elements may deteriorate in some cases, similar to the heating element connected to a HEGO sensor located upstream of the emission control unit. Therefore, in the fifth example, in response to an indication of an S / S event indicating that the temperature of the CMS has dropped below its threshold temperature or desired operating temperature, or in response to a cold start event indicating that the heating element connected to the CMS has deteriorated, the following method can be selected. Specifically, a heater configured to heat the emission control unit can be activated, and the engine can be rotated in the forward or default direction without fuel to direct at least a portion of the heat from the emission control unit to the CMS sensor to raise its temperature to its desired operating temperature. In this example, the throttle valve can be commanded to open at least partially, and the electric supercharger bypass valve can be commanded to open at least partially (if included). Furthermore, the EGR valve can be commanded to remain closed (when included), and the exhaust valve can be commanded to be fully opened (when included). For vehicles equipped with exhaust tuning valves (e.g., 299, 399), the position of the exhaust tuning valve can be controlled to effectively trap heat near the CMS while also avoiding unwanted pressure build-up in the exhaust system, as discussed above.

[0138] In the fifth example variation, instead of rotating the engine in the forward direction without fuel, the electric supercharger can be commanded to open in the forward direction. In this example, the engine cylinders can be sealed, the EGR valve can be commanded to open fully, and the exhaust valve can be commanded to open fully. The exhaust tuning valve can be controlled to keep the heat pinned near the CMS, as discussed. Furthermore, the throttle valve can be commanded to open at least partially, and the electric supercharger bypass valve can be commanded or kept closed.

[0139] In other variations of the fifth example, a laser ignition device can be used, either additionally or alternatively, to generate heat to raise the temperature of the CMS to its desired operating temperature. A method similar to that described above in the third example can be used, where the laser ignition device can be activated with the cylinder sealed to generate the captured in-cylinder heat. The engine can then be rotated in the forward direction to transfer the heat to the CMS sensor, or an electric supercharger can be used to transfer the heat to the CMS sensor, as discussed above. In some examples, the laser ignition device can be used as a supplement to heating the emission control device via a heater coupled to it. For example, heat from the laser ignition device can replace the heat transferred from the emission control device to the CMS sensor, allowing both the CMS and the emission control device to reach their respective desired operating temperatures as quickly as possible.

[0140] Therefore, the examples described above represent a method that can be selected by the controller based on the current vehicle operating conditions and which sensor (e.g., an HEGO sensor located upstream of the emission control unit, or a CMS located downstream of the emission control unit) cannot be heated by its own internal heating element. Once selected, method 600 can proceed to 625. At 625, method 600 may include actively raising the temperature of the specific sensor (e.g., an HEGO sensor located upstream of the emission control unit, or a CMS located downstream of the emission control unit) to its desired operating temperature, as discussed in detail above with respect to the first to the fifth examples. Therefore, proceeding to 630, once the selected method is initiated, method 600 may include indicating whether the temperature of the specific sensor has reached its predetermined threshold temperature or desired operating temperature. If not, then method 600 may return to step 625 of method 600, where the temperature of the specific sensor may be monitored and where the selected method may continue to raise the temperature of the specific sensor to its desired operating temperature using the degraded heating element.

[0141] At 630, in response to an indication that a particular sensor has reached its desired operating temperature or a predetermined threshold temperature, method 600 may proceed to 635. At 635, method 600 may include stopping the active raising of the temperature of the particular sensor that was requested / selected for active heating. More specifically, depending on the method selected, the engine, electric supercharger, various valves (e.g., electric supercharger bypass valve, wastegate, EGR valve, throttle valve, exhaust tuning valve, etc.), and laser ignition device may all return to their respective states prior to executing the method for actively raising the temperature of the particular sensor selected for heating.

[0142] Proceeding to 640, method 600 may include updating vehicle operating parameters. For example, updating vehicle operating parameters may include updating the current temperature of the exhaust oxygen sensor (e.g., an HEGO sensor located upstream of the emission control unit and / or a CMS located downstream of the emission control unit) and the emission control unit. Updating vehicle operating parameters may also include updating the state of charge of the on-board energy storage device to reflect the current state of charge due to the execution of active heating operations. Method 600 may therefore terminate. Although method 600 is depicted as ending after step 640, it is understood that the temperature of the HEGO sensor located upstream of the emission control unit and the temperature of the CMS located downstream of the emission control unit may continue to be monitored during an S / S event or a cold start event, such that if the temperature of a sensor, which also includes a degraded heating element, drops below its desired operating temperature again, then method 600 may be executed again until the engine is started.

[0143] therefore, Figure 6 A method is implemented that includes reducing unwanted emissions during engine start-up events of a vehicle under conditions where the temperature of a heated exhaust oxygen sensor is below its desired operating temperature and the heating element configured to heat the sensor has deteriorated: providing an alternative heat source and actively delivering heat from the source to the sensor to raise the temperature of the sensor to its desired operating temperature.

[0144] As an example, engine starting events may include cold start events. As another example, engine starting events may include start / stop events when the sensor temperature has decreased below its expected operating temperature while the engine is not burning air and fuel.

[0145] In such methods, reducing unwanted emissions may include reducing unwanted emissions at startup compared to conditions where a heated exhaust oxygen sensor remains below its desired operating temperature at startup.

[0146] In such methods, actively delivering heat from the source to the sensor includes one of the following operations: rotating the engine in a forward or reverse direction without fuel, or rotating an electric supercharger positioned in the engine's intake port in a forward or reverse direction. In this example, the forward or reverse direction for rotating the engine and the electric supercharger can be selected based on the sensor's position relative to the emission control unit positioned in the vehicle's engine exhaust system and an alternative heat source. In other words, the direction of rotation of the engine or the electric supercharger can be determined via a controller based on the sensor's position and the heat source provided. More specifically, with the sensor positioned upstream of the emission control unit and the alternative heat source including a heater configured to heat the emission control unit, the engine can be rotated in reverse without fuel, or the electric supercharger can be rotated in reverse. In another example, with the sensor positioned upstream of the emission control unit and the alternative heat source including one or more laser ignition devices configured to provide laser ignition energy to one or more cylinders of the engine, the engine can be rotated in the forward direction without fuel, or the electric supercharger can be rotated in the forward direction. In another example, with the sensor positioned downstream of the emission control unit and the heater of the emission control unit and / or one or both of the laser ignition devices including an alternative heat source, the engine can be rotated in the forward direction without fuel, or the electric supercharger can be rotated in the forward direction.

[0147] In one example of such a method, actively transporting heat from the source to the sensor may include selecting whether to rotate the engine in a forward or reverse direction, in contrast to whether to use the electric supercharger in a forward or reverse direction. Such selection may be based at least on the state of charge of an onboard energy storage device that supplies power to a motor configured to rotate the engine and electric supercharger in a forward or reverse direction.

[0148] Such methods may also include controlling the position of the intake throttle valve and / or exhaust tuning valve to actively deliver heat from the source to the sensor to raise the temperature of the sensor to its desired operating temperature.

[0149] Another example of the method includes, upon engine start-up, in response to the detection of a deteriorated heating element of the oxygen sensor, operating a laser ignition source of the unburned engine and rotating an electrically driven intake compressor to transport heated cylinder gas to the sensor.

[0150] In such methods, the heating element can be configured to raise the temperature of the sensor, and both the heating element and the sensor can be positioned upstream or downstream of an emission control device located in the engine's exhaust system.

[0151] In such methods, the method may further include sealing one or more cylinders of the engine while operating a laser ignition source (or more than one laser ignition source), wherein the one or more cylinders receive laser ignition energy from the laser ignition source. Such methods may also include unsealing the one or more cylinders to transport heated cylinder gases to a sensor via rotating an electrically driven intake compressor. For example, unsealing the one or more cylinders to transport heated cylinder gases to a sensor via rotating an electrically driven intake compressor may further include positioning the one or more cylinders such that both the intake valve and the exhaust valve connected to the one or more cylinders are at least partially open.

[0152] In such methods, the method may further include stopping the operation of the laser ignition source after sealing the cylinder, or maintaining the operation of the laser ignition source after opening the cylinder to transport the cylinder gas to the sensor.

[0153] In such methods, the method may further include commanding the opening of an exhaust valve positioned in an exhaust valve passage, the exhaust valve being configured to deliver fluid flow around the turbine to transport heated cylinder gas to a sensor.

[0154] In such methods, the method may further include commanding the closure of an exhaust recirculation valve located in the exhaust recirculation passage of the engine to transport heated cylinder gases to a sensor.

[0155] In such methods, the method may also include controlling the position of the intake throttle valve and / or exhaust tuning valve to transport the heated cylinder gas to the sensor.

[0156] Turn now Figure 7 An exemplary timeline 700 is shown for actively raising the temperature of the HEGO sensor located upstream of the exhaust catalyst (e.g., 270, 370) during an S / S event when the temperature of the HEGO sensor (e.g., 237, 326) drops below its desired operating temperature and the heating element (e.g., 237a, 326a) connected to the HEGO sensor has deteriorated or otherwise malfunctions as expected. In other words, the exemplary timeline 700 corresponds to the above description regarding... Figure 6The first example described. Timeline 700 includes: graph 705 indicating whether the conditions for actively heating the HEGO sensor are met (yes) or not (no); and graph 710 indicating the state of the engine over time. The engine may be off (not rotating), or it may be rotating in the forward or reverse direction. Timeline 700 also includes: graph 715 indicating the state of fuel injection to the engine; graph 720 indicating the position of the throttle valve (e.g., fully open, fully closed, or somewhere in between); and graph 725 indicating the state of the electrically heated catalyst (emission control device) heater over time. The heater or heating element may be turned on or off over time. Timeline 700 also includes graph 730 indicating the temperature of the emission control device or catalyst over time. Timeline 700 also includes graph 735 indicating the temperature of the HEGO sensor located upstream of the emission control device or exhaust catalyst over time.

[0157] At time t0, the engine rotates in the forward direction (curve 710) and fuel is supplied to the engine (curve 715). Although not explicitly stated, it is understood that spark or laser ignition energy is also supplied to the engine cylinders at time t0. The throttle position (curve 720) varies according to the driver's needs. The heating element configured to heat the emission control device is off (curve 725), the temperature of the emission control device is above its desired operating temperature (e.g., ignition temperature) (curve 730), indicated by dashed line 731, and the temperature of the HEGO sensor (curve 735) is above its desired operating temperature, indicated by dashed line 736.

[0158] Between times t0 and t1, driver demand decreases (Graph 720), and at time t1, the S / S event begins. More specifically, the engine is deactivated (Graph 710) and fuel injection to the engine cylinders ceases (Graph 715). Therefore, at time t1, the engine is no longer burning air and fuel.

[0159] Between times t1 and t2, the temperature of the emission control device (curve 730) and the temperature of the HEGO sensor (curve 735) remain above their respective desired operating temperatures. However, at time t2, the temperature of the HEGO sensor drops below its desired operating temperature. Therefore, at time t2, the controller determines whether the conditions for actively raising the temperature of the HEGO sensor are met, and thus indicates that such conditions are met at time t2. This has already been stated above. Figure 6Such conditions have been described in detail elsewhere and will therefore not be repeated here for the sake of brevity. However, it is understood that the heating element configured to raise the temperature of the HEGO sensor may have deteriorated or otherwise malfunctioned as expected. Therefore, it is necessary to actively heat the HEGO sensor by other means.

[0160] Therefore, at time t2, the heating element connected to the emission control device is activated (curve 725). At time t3, the engine is rotated in the reverse direction without fuel (curves 710 and 715), and the throttle is commanded to a position that can trap heat near the HEGO sensor but avoid unwanted pressure buildup in the engine system.

[0161] Between times t3 and t4, with the heating element for heating the emission control unit activated and the engine rotated in the reverse direction, the temperature of the HEGO sensor increases (Graph 735). It can be understood that the engine can be rotated in the reverse direction at a predetermined RPM to transfer heat from the emission control unit to the HEGO sensor.

[0162] Between times t3 and t4, the temperature of the HEGO sensor rises above its desired operating temperature (Graph 735). Therefore, at time t4, the conditions for actively raising the HEGO temperature are no longer indicated (Graph 705). Consequently, the engine is stopped from rotating in reverse without fuel (Graph 710), the throttle returns to its default position before the active heating operation (Graph 720), and the heating element for heating the emission control device is shut off (Graph 725).

[0163] Between times t4 and t5, the temperature of the HEGO sensor remains above its expected operating temperature (Graph 735), as does the temperature of the emission control unit (Graph 730). Therefore, no further action is taken between times t4 and t5.

[0164] At time t5, an engine torque request greater than a predetermined threshold is initiated, and the engine is thus restarted to rotate in the forward direction with fuel injection provided (Graph 710). Although not explicitly stated, it can be understood that engine starting may include rotation via a starter motor, which has been omitted for simplicity.

[0165] Between time t5 and t6, the throttle position (curve 720) changes according to the driver's needs, while the engine operates to burn air and fuel to propel the vehicle.

[0166] Turn now Figure 8An exemplary timeline 800 is shown for actively raising the temperature of an HEGO sensor located upstream of an exhaust catalyst (e.g., 270, 370) during an S / S event when the temperature of the HEGO sensor (e.g., 237, 326) drops below its desired operating temperature and the heating element (e.g., 237a, 326a) coupled to the HEGO sensor has deteriorated or otherwise malfunctions as desired. In the exemplary timeline 800, the method selected for actively raising the temperature of the HEGO sensor includes rotating the electric supercharger in the reverse direction. Therefore, the exemplary timeline 800 corresponds to the above description regarding... Figure 6 The second example described. It is understood that such selection can be based on the current state of charge of the onboard energy storage device, as reversing the rotation of the electric supercharger may not be as demanding or expensive as reversing the rotation of the engine without fuel. Timeline 800 includes: graph 805 indicating whether the conditions for actively heating the HEGO sensor are met (yes) or not (no); and graph 810 indicating the state of the engine over time. The engine may be off (not rotating), or it may be rotating in either the forward or reverse direction. Timeline 800 also includes: graph 815 indicating the state of fuel injection to the engine; graph 820 indicating the position of the throttle (e.g., fully open, fully closed, or somewhere in between); and graph 825 indicating the state of the electrically heated catalytic converter (emission control device) heater over time. Timeline 800 also includes graph 830 indicating the temperature of the emission control device or catalyst over time. Timeline 800 also includes graph 835, which indicates the temperature of the HEGO sensor located upstream of the emission control unit or exhaust catalyst over time. Timeline 800 also includes: graph 840, which indicates the state of the exhaust valve (fully open or fully closed); graph 845, which indicates the state of the EGR valve (fully open or fully closed); and graph 850, which indicates the state of the electric supercharger over time (closed or reverse-open).

[0167] At time t0, the engine is rotating in the forward direction (curve 810), where fuel injection is provided to the engine (curve 815). Although not explicitly stated, it is understood that spark or laser ignition energy is also provided to the engine cylinders. In other words, at time t0, the engine is burning air and fuel. The throttle is controlled according to the driver's needs (curve 820). The emission control device is not heated (curve 825) because the engine is operating and the temperature of the emission control device (curve 830) is higher than its expected operating temperature, as indicated by line 831. Furthermore, the temperature of the HEGO sensor located upstream of the emission control device is higher than its expected operating temperature, as indicated by line 836. The exhaust valve is closed (curve 840), the EGR valve is closed (curve 845), and the electric supercharger is not operating (curve 850). The conditions for actively heating the HEGO have not yet been met (curve 805). Although not explicitly stated, it is understood that this indicates the heating element (e.g., 237a, 326a) used to heat the HEGO sensor has deteriorated or is otherwise not functioning as expected.

[0168] Between times t0 and t1, driver demand decreases (curve 820), and at time t1, the S / S event begins. More specifically, the engine is deactivated (curve 810), and fuel injection to the engine cylinders ceases (curve 815). Although not explicitly stated, it can be understood at time t1 that spark or laser ignition energy to the engine cylinders also ceases.

[0169] When the engine stops burning air and fuel at time t1, the catalyst temperature drops slightly (graph 830), and the temperature of the HEGO sensor located upstream of the emission control unit decreases. At time t2, the temperature of the upstream HEGO sensor drops below its desired operating temperature, as indicated by line 836. Therefore, since the controller has determined that the heating element connected to the HEGO sensor is not operating as expected, a condition for actively raising the temperature of the HEGO sensor is indicated (graph 805). In this exemplary timeline, although not explicitly stated, it can be understood that when the condition is met at time t2, the controller selects a method for actively raising the temperature of the HEGO sensor, which includes using an electric supercharger instead of reversing the engine (or using a laser ignition device). Such a method can be selected, for example, based on the current determination of the state of charge of the onboard energy storage device. More specifically, a state of charge below a predetermined state of charge threshold may make it more desirable to perform an active increase in the temperature of the HEGO sensor via an electric supercharger than to reverse the engine. In another example, this determination could be made solely based on whether an electric supercharger is included in the engine system. This determination could be further based on, for example, whether the engine includes a variable displacement engine.

[0170] In the case where the method of actively raising the temperature of the HEGO sensor is selected at time t2, the heater connected to the emission control device is activated (Figure 825). At time t3, the exhaust valve is commanded to open (Figure 840), the EGR valve is commanded to open (Figure 845), and the throttle valve is commanded to reach at least a partially open position (Figure 820), a position where the pressure buildup in the engine intake is kept below an undesirable level but desirable heat can be trapped near the HEGO sensor. Furthermore, although not explicitly stated, it is understood that at time t3, the engine cylinders may be sealed (e.g., by commanding the intake and exhaust valves to close via the VDE actuator). However, in other examples, the engine cylinders may not be sealed without departing from the scope of this disclosure. For example, because the engine presents significant resistance to airflow, air may be preferentially delivered to the vicinity of the engine via the EGR passage, even if the engine cylinders are not actively sealed. Furthermore, although not explicitly stated, it is understood that at time t3, the electric booster bypass valve (e.g., 361) is commanded or maintained closed.

[0171] At time t3, the electric supercharger is started in reverse, provided that the throttle valve is controlled to reach its desired position, the wastegate and EGR valve are fully opened, the engine cylinders are sealed, and the electric supercharger bypass valve is fully closed. Reverse operation can be achieved via, for example, an H-bridge as discussed above. For instance, the reverse rotational speed of the electric supercharger can include a predetermined speed (RPM).

[0172] When the electric supercharger is activated between times t3 and t4, the temperature of the HEGO sensor located upstream of the emission control unit rises and becomes higher than the desired operating temperature, as indicated by line 836. At time t4, when the HEGO sensor temperature has reached / exceeded its desired operating temperature, the conditions for actively heating the HEGO sensor are no longer indicated (graph 805). Therefore, the throttle (graph 820) returns to its position before performing the active HEGO heating diagnostic, shuts off the heating connected to the emission control unit (graph 825), commands the exhaust valve (graph 840) and EGR valve to close completely (graph 845), and deactivates the electric supercharger (graph 850). Between times t4 and t5, the temperature of the HEGO sensor, as well as the temperature of the emission control unit or exhaust catalyst, remains above their respective desired operating temperatures. Therefore, no further action is taken between times t4 and t5.

[0173] At time t5, the controller indicates / determines an engine torque demand request exceeding the threshold torque requirement. Therefore, the engine is started to rotate in the forward direction (curve 810), and fuel injection is provided to the engine cylinders (curve 815). In other words, the engine is started at time t5 to burn air and fuel. As discussed above, such actions may include the starter motor initially rotating the engine until the engine can rotate on its own via the combustion of air and fuel. However, for the sake of simplicity / clarity, such details are not included at timeline 800. Furthermore, it is understood that after starting the engine and providing fuel injection to the engine cylinders, spark or laser ignition energy may be additionally provided to the engine cylinders. With the engine burning air and fuel, the throttle is controlled according to the driver's needs between times t5 and t6 (curve 820).

[0174] Turn now Figure 9This illustrates another exemplary timeline 900 for actively raising the temperature of an HEGO sensor located upstream of an exhaust catalyst (e.g., 270, 370) during an S / S event when the temperature of the HEGO sensor (e.g., 237, 326) drops below its desired operating temperature and the heating element (e.g., 237a, 326a) coupled to the HEGO sensor has deteriorated or otherwise malfunctions as desired. In exemplary timeline 900, the method selected for actively raising the temperature of the HEGO sensor includes using a laser ignition device to induce heat in the engine cylinder, wherein such heat can then be delivered to the HEGO sensor to raise its temperature to or above its desired operating temperature. Therefore, exemplary timeline 900 corresponds to the above regarding… Figure 6 The third example described. Timeline 900 includes: graph 905 indicating whether conditions for actively heating the HEGO sensor are met; graph 910 indicating the engine's state over time (off, or rotating in the forward or reverse direction); graph 915 indicating the state of fuel injection to the engine over time; and graph 920 indicating the throttle position over time (fully open or fully closed, or somewhere in between). Timeline 900 also includes graph 925 indicating the state (on or off) of heating elements coupled to the emission control unit or exhaust catalyst over time. Timeline 900 also includes: graph 930 indicating the temperature of the emission control unit over time; and graph 935 indicating the temperature of the HEGO sensor located upstream of the emission control unit over time. Timeline 900 also includes: graph 940, indicating the state of the exhaust valve over time (fully open or fully closed); graph 945, indicating the state of the EGR valve over time (fully open or fully closed); graph 950, indicating the state of the laser ignition device connected to the engine cylinder over time (on or off); and graph 955, indicating the state of the engine cylinder over time (sealed or open). As discussed, and although not explicitly stated, it is understood that for timeline 900, the heating element connected to the HEGO sensor is known to have deteriorated.

[0175] At time t0, the conditions for actively heating the HEGO sensor have not yet been indicated (curve 905). The engine is rotating in the forward direction (curve 910), providing fuel injection to the engine cylinders (curve 915) and providing laser ignition energy to the engine cylinders (curve 950). In other words, the engine is burning air and fuel to propel the vehicle. The throttle position at time t0 (curve 920) varies according to driver demand, the emission control unit temperature (curve 930) is above its threshold temperature or desired operating temperature, indicated by line 931, and the HEGO sensor (curve 935) is above its threshold temperature or desired operating temperature, indicated by line 936. Therefore, the heater or heating element connected to the emission control unit is closed (curve 925). Furthermore, the exhaust valve is closed (curve 940), the EGR valve is closed (curve 945), and the engine cylinders are not yet actively sealed (curve 950).

[0176] Between times t0 and t1, driver demand decreases (curve 920), and at time t1, the S / S event begins. Therefore, the engine is deactivated (curve 910), fuel injection to the engine cylinders stops (curve 915), and the laser ignition device is deactivated (curve 950). Between times t1 and t2, with the engine not burning, the temperature of the HEGO sensor decreases (curve 935). At time t2, the temperature of the HEGO sensor (curve 935) drops below the threshold temperature or the desired operating temperature, as indicated by line 936. Therefore, when it has been determined that the HEGO sensor heating element has deteriorated, it indicates that the conditions for actively heating the HEGO sensor are met (curve 905). Therefore, at time t2, it can be understood that a method for actively raising the temperature of the HEGO sensor can be selected via the controller. In this example, this selection is made based on the inclusion of a laser ignition device in the engine system combined with the engine including a variable displacement engine. Therefore, at time t3, for example, a signal is sent via the controller to the VDE actuator to actuate the intake and exhaust valves connected to the engine cylinders to close, thereby actively sealing the engine cylinders (Figure 955). Although not explicitly stated, it can be understood that any number of cylinders can be actively sealed at time t3.

[0177] Regardless of which cylinder is actively sealed at time t3, laser ignition energy is supplied to that cylinder at time t4 (Graph 950). Furthermore, at time t3, the throttle valve is controlled (Graph 920) to reach its desired position, the wastegate is commanded to fully open (Graph 940), and the EGR valve is maintained / commanded to close (Graph 945). With laser ignition energy supplied to the sealed cylinder, heat is generated in the sealed cylinder between times t4 and t5. The amount of ignition energy supplied and the duration of supplying the ignition energy can each include a predetermined amount and duration. The ignition energy can be supplied in the form of pulses, where the pulse rate can include a predetermined pulse rate. In some examples, an in-cylinder temperature sensor can be included to raise the temperature in the cylinder to a desired temperature for actively heating the HEGO sensor.

[0178] At time t5, the command to open the cylinder is executed (curve 955), and the engine begins to rotate in the forward direction (curve 910) without fuel (curve 915). This engine rotation transports the captured in-cylinder heat to the HEGO sensor located upstream of the emission control unit. In this exemplary timeline, laser ignition energy continues to be provided at time t5; in other examples, the provided laser ignition energy may be stopped in response to the engine rotating in the forward direction without fuel. Furthermore, although not explicitly stated, it is understood that in some examples, as discussed above, instead of rotating the engine without fuel to transfer the heated in-cylinder gas to the HEGO sensor, the electric supercharger may be electrically rotated in the forward direction to provide compressed air to transfer the heated in-cylinder gas to the HEGO sensor. In this example, it is understood that opening the cylinder can also refer to the cylinder receiving laser ignition energy being positioned or controlled such that its intake and exhaust valves are both at least partially open.

[0179] Between times t5 and t6, the temperature of the HEGO sensor rises (Graph 935), and at time t6, the temperature reaches its desired operating temperature. Since the HEGO sensor has reached its desired operating temperature, the conditions for actively heating the HEGO sensor are no longer indicated (Graph 905). Therefore, the throttle (Graph 920) returns to its position before actively raising the HEGO sensor temperature, commands the exhaust valve to close (Graph 940), and disables or shuts off the laser ignition system (Graph 950). Furthermore, the engine stops rotating in the forward direction without fuel (Graph 915) (Graph 910).

[0180] Between times t6 and t7, the temperature of the HEGO sensor remains above its threshold / desired operating temperature, and therefore no further action is taken. At time t7, the driver's demand for engine torque exceeds a predetermined threshold demand, and therefore, the engine is started to rotate in the forward direction (Figure 910) while providing fuel injection (Graph 915) and laser ignition energy (Graph 950) to the engine cylinders. As discussed, the starter motor could initially be used to rotate the engine mass until the engine can rotate under its own power from combustion, but such details are omitted for simplicity. Between times t7 and t8, as the engine propels the vehicle, the throttle is controlled according to the driver's demand.

[0181] Turn now Figure 10 An exemplary timeline 1000 is shown for actively raising the temperature of the HEGO sensor (e.g., 237, 326) located upstream of the exhaust catalyst (e.g., 270, 370) during a cold start event in the event that the heating element (e.g., 237a, 326a) coupled to the HEGO sensor has deteriorated or otherwise does not operate as expected or anticipated. In exemplary timeline 1000, the method selected for actively raising the temperature of the HEGO sensor includes using a laser ignition device to induce heat in the engine cylinder, wherein such heat can then be transported to the HEGO sensor to raise the temperature of the HEGO sensor to its desired operating temperature or above its desired operating temperature. Therefore, timeline 1000 corresponds to the above regarding Figure 6The fourth example described. Timeline 1000 includes graph 1001, which indicates whether a cold start event is indicated / determined over time via the vehicle controller (yes or no). Timeline 1000 also includes: graph 1005, which indicates whether conditions for actively heating the HEGO sensor are met (yes or no); graph 1010, which indicates the engine state over time (off, or rotating in the forward or reverse direction); graph 1015, which indicates the fuel injection state to the engine cylinders over time (on or off); graph 1020, which indicates the position of the intake throttle valve over time (fully open, fully closed, or somewhere in between); and graph 1025, which indicates the state of the heating element coupled to the emission control unit over time (on or off). Timeline 1000 also includes: graph 1030, which indicates the temperature of the emission control unit over time; and graph 1035, which indicates the temperature of the HEGO sensor located upstream of the emission control unit or catalyst over time. The timeline 1000 also includes: graph 1040, which indicates the state of the exhaust valve over time (fully open or fully closed); graph 1045, which indicates the state of the engine cylinder over time (sealed or open); and graph 1050, which indicates the state of the laser ignition device configured to provide laser ignition energy to the engine cylinder over time (on or off).

[0182] At time t0, no cold start event is indicated (Graph 1001). In other words, no on-time event occurs, and there is no request for engine torque. Therefore, the conditions for actively heating the HEGO sensor are not met (Graph 1005), the engine is shut off (Graph 1010), fuel injection to the engine cylinders is shut off (Graph 1015), the throttle is in the off default position (Graph 1020), the heater or heating element connected to the emission control unit or catalytic converter is off (Graph 1025), the catalytic converter temperature is low (Graph 1030), the HEGO sensor temperature is low (Graph 1035), the exhaust valve is closed (Graph 1040), the engine cylinders are not actively sealed (Graph 1045), and the laser ignition device is off (Graph 1050).

[0183] Between times t0 and t1, the conditions described for time t0 are maintained. At time t1, a cold start event begins (Graph 1001). Thus, when it is indicated that the HEGO sensor heating element has deteriorated, it indicates that the conditions for actively raising the temperature of the HEGO sensor are met (Graph 1005). At time t1, it is understood that the controller can make a selection regarding the method used to raise the temperature of the HEGO sensor to its desired operating temperature or above its desired operating temperature. In this exemplary timeline 1000, it is understood that the selected method includes using laser ignition energy via a laser ignition device to generate heat in the engine cylinder, wherein this heat is subsequently transferred or transported to the HEGO sensor to increase its temperature. This method can be selected in response to an indication that the engine system includes a laser ignition device and that the engine cylinders can be actively sealed (e.g., in a variable displacement engine). However, it is understood that this method can be implemented not only in variable displacement engines, as the engine can be controlled (e.g., via rotation without fuel) to a position where at least one cylinder can have closed intake and exhaust valves. However, in this exemplary timeline, the engine includes a variable displacement engine.

[0184] Therefore, at time t1, if this method is selected, a signal is sent via (e.g.) the controller to the VDE actuator to command the sealing of the engine cylinders by sealing the intake and exhaust valves (Figure 1045). Any number of engine cylinders can be sealed in this manner. At time t2, the laser ignition device is actuated (Figure 1050). It is understood that only the laser ignition device corresponding to those cylinders being sealed is actuated. Furthermore, at time t2, the heater or heating element connected to the emission control device or exhaust catalyst is actuated (Figure 1025).

[0185] Between times t2 and t3, with the heater configured to heat the emission control device activated, the temperature of the emission control device rises (Graph 1030). At time t3, the engine cylinders are opened (Graph 1045), the wastegate is commanded to open (Graph 1040), the throttle is controlled to its desired position (Graph 1020), and the engine is started to rotate in the forward direction (Graph 1010) without fuel (Graph 1015). With the engine cylinders opened and the engine rotating in the forward direction, the captured in-cylinder heat is transferred to the HEGO sensor to increase its temperature.

[0186] Therefore, between times t3 and t4, the temperature of the HEGO sensor located upstream of the exhaust catalyst (plot 1035) increases, and the temperature of the exhaust catalyst also increases (plot 1030). It can be understood that the increase in the exhaust catalyst temperature can be attributed in part to the activation of the heating element connected to the emission control device or the exhaust catalyst, and further in part to the heat transported from the cylinders to the exhaust system via positive engine rotation in the absence of fuel.

[0187] At time t4, the temperatures of the exhaust catalyst and the HEGO sensor reach their desired operating temperatures, represented by lines 1031 and 1036, respectively. Therefore, the conditions for actively heating the HEGO sensor are no longer indicated (curve 1005). Consequently, the throttle (curve 1020) returns to its position before performing the diagnostics to raise the HEGO sensor temperature, deactivating the heater connected to the emission control unit (curve 1025), commanding the exhaust valve to close (curve 1040), and commanding the laser ignition device to shut off (curve 1050). The engine is maintained rotating in the forward direction between times t4 and t5, and at time t5, fuel injection and laser ignition energy are supplied to the engine cylinders (curves 1015 and 1050). With fuel injection and laser ignition energy supplied to the engine cylinders, it can be understood that the engine is burning air and fuel at time t5. Between times t5 and t6, the throttle is controlled according to the driver's needs.

[0188] Turn now Figure 11 An exemplary timeline 1100 is shown for actively raising the temperature of an HEGO sensor located downstream of the emission control device, referred to herein as the CMS (e.g., 298, 398), when the heating element (e.g., 298a, 398a) configured to heat the CMS has deteriorated or otherwise failed to operate as expected or anticipated. Timeline 1100 depicts an example of such active heating of the CMS during an S / S event when the temperature of the CMS decreases below its desired operating temperature or threshold temperature due to engine shutdown. Thus, timeline 1110 represents a timeline corresponding to the above regarding... Figure 6The fifth example of the timeline discussed. Timeline 1100 includes: graph 1105, indicating whether the conditions for actively heating the HEGO sensor (CMS) located downstream of the emission control device are met (yes or no); graph 1110, indicating the engine state over time (off, or rotating in the forward or reverse direction); graph 1115, indicating the fuel injection state to the engine cylinders over time (on or off); graph 1120, indicating the position of the intake throttle valve over time (fully open, fully closed, or somewhere in between); graph 1125, indicating the state of the heater or heating element connected to the emission control device over time (on or off); graph 1130, indicating the temperature of the emission control device or exhaust catalyst over time; and graph 1135, indicating the temperature of the CMS over time.

[0189] At time t0, the conditions for actively heating the CMS are not indicated (curve 1105). The engine is rotating in the forward direction (curve 1110) and fuel injection is being provided to the engine cylinders (curve 1115). Although not explicitly stated, it can be understood that spark or laser ignition energy is also being provided to the engine cylinders at time t0. In other words, at time t0, the engine is burning air and fuel to propel the vehicle. The throttle position (curve 1120) varies according to the driver's needs, and the heater connected to the emission control unit (curve 1125) is off when the engine is operating. Furthermore, the temperature of the emission control unit (curve 1130) is above its threshold temperature or desired operating temperature, as indicated by line 1131, and the temperature of the CMS (curve 1135) is above its threshold temperature or desired operating temperature, as indicated by line 1136.

[0190] Between times t0 and t1, driver demand decreases (Graph 1120), and at time t1, the S / S event begins. Therefore, the engine is deactivated (Graph 1110), fuel injection to the engine ceases (Graph 1115), and, although not explicitly stated, spark or laser ignition energy is also stopped at time t1.

[0191] Between times t1 and t2, when the engine is not burning air and fuel, the temperature of the CMS decreases, and at time t2, the temperature of the CMS drops below its desired operating temperature, as indicated by line 1136. Therefore, the conditions for actively heating the CMS (graph 1105) are met, and it can thus be understood that the controller selects a method for actively raising the temperature of the CMS. In this exemplary timeline, the selected method includes activating the heating element coupled to the emission control unit, followed by forward rotation of the engine without fuel. This method can be selected, for example, if the engine is not equipped with an electric supercharger, if ignition energy is supplied to the engine cylinders via spark plugs instead of a laser ignition system, or if the state of charge of the onboard energy storage device is greater than a predetermined threshold state of charge, etc.

[0192] When this method is selected, the heater connected to the emission control unit is activated at time t2 (curve 1125). At time t3, the throttle is controlled to reach its desired position (curve 1120), and the engine is started via the motor (curve 1110) to rotate in the forward direction without fuel (curve 1115). Between times t3 and t4, heat from the emission control unit is transferred to the CMS, thus increasing the CMS temperature (curve 1135) above the threshold temperature or the desired operating temperature. Therefore, at time t4, when the CMS temperature has actively risen above the threshold temperature, the conditions for actively heating the CMS (curve 1105) are no longer indicated. Therefore, at time t4, engine rotation without fuel (curve 1110) is stopped, the throttle is commanded (curve 1120) to reach its position before the active heating diagnostics were performed, and the heater connected to the emission control unit (curve 1125) is deactivated. Between times t4 and t5, the temperature of the CMS (plot 1135) remains above the threshold temperature, as indicated by line 1136, and therefore no further action is taken.

[0193] At time t5, the engine torque demand exceeds the threshold, and thus the engine starts to rotate in the positive direction (curve 1110), and fuel is supplied to the engine cylinders (curve 1115). Although not explicitly stated, it can be understood that spark or laser ignition energy is supplied to the engine cylinders at time t5. In other words, at time t5, engine combustion begins. As discussed, the starter motor could initially be used to rotate the engine mass; however, this step is not indicated here for the sake of simplicity.

[0194] Between time t5 and t6, the throttle valve is controlled according to the driver's needs.

[0195] exist Figures 7 to 11 The timeline depicted shows about Figure 6 The method described is for a selected number of examples. Although not every variation of all examples is shown, it can be understood from the above regarding Figure 6 Any changes described may be used to actively increase the temperature of an HEGO sensor located upstream of the emission control unit or downstream of the emission control unit, depending on the current vehicle / engine operating conditions and, more importantly, the functionality of the component portion of the particular vehicle / engine system that undergoes active HEGO sensor heating diagnostics.

[0196] In this way, even when the heating elements indicating that the HEGO sensors, configured to increase the temperature of those located upstream or downstream of the emission control unit, have deteriorated, active heating using the systems and methods discussed herein can enable the HEGO sensors to be heated to or above their desired operating temperature during S / S events or cold start events. Such action can reduce unwanted emissions to the atmosphere, increase the lifespan of emission control units located in the engine exhaust system, and potentially increase engine life.

[0197] A technical effect is the recognition that, in cases where the heating element configured to raise the HEGO sensor temperature has deteriorated, an alternative heat source can be used during S / S events or cold start events to raise the HEGO sensor temperature to or above its desired operating temperature. Therefore, another technical effect is the recognition that hybrid vehicles can have means for transporting heat generated from the alternative heat source to the HEGO sensor via energy stored on-board (e.g., in an on-board energy storage device). Thus, one technical effect is the recognition that heat from emission control devices can be transported to the HEGO sensor, and another is the recognition that the temperature of the HEGO sensor can be raised using in-cylinder heat captured via a laser ignition device. Another technical effect is the recognition that various methods can be used to transport heat to the HEGO sensor, including engine rotation without fuel or operation of an electric supercharger positioned in the engine intake. Another technical effect is the recognition that there may be situations where a particular method for raising the HEGO sensor temperature is more desirable than other potential methods, and therefore such method selection can be based on current vehicle operating parameters, engine system component parts, etc.

[0198] This article references Figures 1 to 5B The system described and the references in this article Figure 6The described methods can implement one or more systems and one or more methods. In one example, a method includes reducing unwanted emissions during an engine start-up event of a vehicle propelled by providing an alternative heat source and actively delivering heat from the source to the sensor to raise the sensor's temperature to its desired operating temperature. In a first example of the method, the method further includes wherein the engine start-up event includes a cold start event. A second example optionally includes the first example and further includes wherein the engine start-up event includes a start / stop event in which the sensor temperature has decreased below its desired operating temperature when the engine is not burning air and fuel. A third example optionally includes any one or more of the first to second examples and further includes wherein reducing unwanted emissions includes reducing unwanted emissions during the start-up event compared to conditions where the heated exhaust oxygen sensor remains below its desired operating temperature during the start-up event. The fourth example optionally includes any one or more or each of the first to third examples, and further includes wherein actively transporting heat from the source to the sensor includes either rotating the engine in a forward or reverse direction without fuel or rotating an electric supercharger located in the engine's intake port in a forward or reverse direction, the forward or reverse direction of rotating the engine and the electric supercharger being selected based on the position of the sensor relative to the emission control device and alternative heat source located in the exhaust system of the vehicle's engine. The fifth example optionally includes any one or more or each of the first to fourth examples, and further includes rotating the engine in reverse or the electric supercharger in reverse when the sensor is located upstream of the emission control device and the alternative heat source includes a heater configured to heat the emission control device; rotating the engine in the forward direction or the electric supercharger in the forward direction when the sensor is located upstream of the emission control device and the alternative heat source includes one or more laser ignition devices configured to provide laser ignition energy to one or more cylinders of the engine; and rotating the engine in the forward direction or the electric supercharger in the forward direction when the sensor is located downstream of the emission control device and one or both of the heater and / or one or more laser ignition devices configured to heat the emission control device include an alternative heat source.A sixth example optionally includes any one or more, or each of the first to fifth examples, and further includes wherein actively delivering heat from the source to the sensor comprises whether the engine is used in a forward or reverse direction compared to whether the electric supercharger is used in a forward or reverse direction, the selection being at least based on the state of charge of an onboard energy storage device that supplies power to a motor configured to rotate the engine and the electric supercharger in a forward or reverse direction. A seventh example optionally includes any one or more, or each of the first to sixth examples, and further includes controlling the position of the intake throttle valve and / or exhaust tuning valve to actively deliver heat from the source to the sensor to raise the temperature of the sensor to its desired operating temperature.

[0199] Another example of the method includes, upon engine start-up, in response to detection of a deteriorated heating element of the oxygen sensor, operating a laser ignition source of the unburned engine and rotating an electrically driven intake compressor to transport heated cylinder gases to the sensor. In a first example of the method, the method further includes wherein the heating element is configured to raise the temperature of the sensor, and wherein both the heating element and the sensor are positioned upstream or downstream of an emission control device located in the engine's exhaust system. A second example of the method optionally includes the first example and further includes sealing an engine cylinder upon operation of the laser ignition source, wherein the cylinder receives laser ignition energy from the laser ignition source; and opening the cylinder to transport heated cylinder gases to the sensor via rotating the electrically driven intake compressor. A third example of the method optionally includes any one or more of the first to second examples and further includes wherein opening the cylinder further includes positioning the cylinder such that both the intake and exhaust valves coupled to the cylinder are at least partially open. A fourth example of the method optionally includes any one or more of the first to third examples, and further includes stopping operation of the laser ignition source after the cylinder is opened, or maintaining operation of the laser ignition source after the cylinder is opened, to transport cylinder gases to the sensor. A fifth example of the method optionally includes any one or more of the first to fourth examples, and further includes commanding the opening of an exhaust valve located in an exhaust valve passage, the exhaust valve being configured to deliver fluid flow to the turbine to transport heated cylinder gases to the sensor. A sixth example of the method optionally includes any one or more of the first to fifth examples, and further includes commanding the closing of an exhaust recirculation valve located in an exhaust recirculation passage of the engine to transport heated cylinder gases to the sensor. A seventh example of the method optionally includes any one or more of the first to sixth examples, and further includes controlling the position of the intake throttle valve and / or exhaust tuning valve to transport heated cylinder gases to the sensor.

[0200] A system for a hybrid vehicle includes a controller having computer-readable instructions stored in a non-transitory memory. Upon execution, the computer-readable instructions cause the controller to: activate an electric heat source under the conditions of an engine start-up event, in the event that the heating element of a heated exhaust oxygen sensor has deteriorated, and actively deliver heat from the electric heat source to the heated exhaust oxygen sensor to increase its temperature to a desired operating temperature. The active delivery of heat from the heat source to the heated exhaust oxygen sensor includes, based on the location of the heated exhaust oxygen sensor with its deteriorated heating element and the electric heat source, rotating the engine in a forward or reverse direction via a motor without fuel. In a first example of the system, the system further includes, wherein the electric heat source also includes a heater coupled to an emission control device located in the engine's exhaust system, or one or more laser ignition devices configured to provide laser ignition energy to one or more cylinders of the engine. A second example of the system optionally includes the first example and further includes an intake throttle valve; an exhaust tuning valve; and wherein the controller stores additional instructions for controlling the position of one or more of the throttle valve and / or exhaust tuning valve such that heat from an electric heating source is trapped near a heated exhaust oxygen sensor while preventing unwanted pressure build-up in the engine. A third example of the system optionally includes any one or more, or each of the first to second examples and further includes an electric supercharger positioned in the intake port of the engine; and wherein the controller stores additional instructions for selecting to actively deliver heat from a heat source to a heated exhaust oxygen sensor using an electric supercharger that rotates in a forward or reverse direction via a motor, instead of the engine.

[0201] It should be noted that the exemplary control and estimation routines included herein can be used in various engine and / or vehicle system configurations. The control methods and routines disclosed herein can be stored as executable instructions in non-transitory memory and can be executed by a control system comprising a combination of controllers and various sensors, actuators, and other engine hardware. The specific routines described herein can represent one or more of any number of processing strategies, such as event-driven, interrupt-driven, multitasking, multithreading, etc. Therefore, the various actions, operations, and / or functions described may be performed in the illustrated sequence, in parallel, or in some cases omitted. Similarly, the processing order is not necessarily required to achieve the features and advantages of the exemplary embodiments described herein, but is provided for the sake of simplicity of illustration and description. One or more of the illustrated actions, operations, and / or functions can be repeatedly performed according to the specific strategy used. Furthermore, the described actions, operations, and / or functions can clearly represent code to be programmed into a non-transitory memory of a computer-readable storage medium in the engine control system, wherein the described actions are implemented by executing instructions in a system comprising a combination of various engine hardware components and electronic controllers.

[0202] It will be understood that the configurations and routines disclosed herein are exemplary in nature and should not be viewed in a limiting sense, as numerous variations are possible. For example, the above techniques can be applied to V-6, I-4, I-6, V-12, opposed 4-cylinder, and other engine types. The subject matter of this disclosure includes all novel and non-obvious combinations and sub-combinations of the various systems and configurations disclosed herein with other features, functions, and / or properties.

[0203] The appended claims specifically point to particular combinations and sub-combinations considered novel and non-obvious. These claims may refer to an element or a first element or its equivalent. Such claims should be understood to include one or more such elements, neither requiring nor excluding two or more such elements. Other combinations and sub-combinations of the disclosed features, functions, elements, and / or properties may be claimed by amending these claims or by presenting new claims in this or related applications. Such claims, whether broader, narrower, equivalent, or different in scope from the original claims, are also considered to be included within the subject matter of this disclosure.

[0204] According to the present invention, a method includes reducing unwanted emissions during an engine start-up event of a vehicle under conditions where the temperature of a heated exhaust oxygen sensor is below its desired operating temperature and the heating element configured to heat the sensor has deteriorated: providing an alternative heat source and actively delivering heat from the source to the sensor to raise the temperature of the sensor to its desired operating temperature.

[0205] According to the implementation plan, engine starting events include cold start events.

[0206] According to the implementation plan, engine start-up events include start / stop events when the sensor temperature has decreased below its expected operating temperature while the engine is not burning air and fuel.

[0207] According to the implementation plan, another example of reducing unwanted emissions includes reducing unwanted emissions during startup events compared to conditions where heated exhaust oxygen sensors are kept below their desired operating temperature during startup events.

[0208] According to the implementation scheme, actively delivering heat from the source to the sensor includes either rotating the engine in a forward or reverse direction without fuel or rotating an electric supercharger located in the engine's air intake in a forward or reverse direction, the forward or reverse direction of rotating the engine and the electric supercharger being selected based on the position of the sensor relative to the emission control device and alternative heat source located in the exhaust system of the vehicle's engine.

[0209] According to the embodiments, the invention is further characterized in that, when the sensor is located upstream of the emission control device and the alternative heat source includes a heater configured to heat the emission control device, the engine is rotated in the reverse direction without fuel or the electric supercharger is rotated in the forward direction without fuel; when the sensor is located upstream of the emission control device and the alternative heat source includes one or more laser ignition devices configured to provide laser ignition energy to one or more cylinders of the engine, the engine is rotated in the forward direction without fuel or the electric supercharger is rotated in the forward direction without fuel; and when the sensor is located downstream of the emission control device and one or both of the heater and / or one or more laser ignition devices configured to heat the emission control device include an alternative heat source, the engine is rotated in the forward direction without fuel or the electric supercharger is rotated in the forward direction without fuel.

[0210] According to the implementation scheme, actively transporting heat from the source to the sensor includes selecting whether to use the engine in the forward or reverse direction compared to whether to use the electric supercharger in the forward or reverse direction, the selection being based at least on the state of charge of an onboard energy storage device that supplies power to a motor configured to rotate the engine and the electric supercharger in the forward or reverse direction.

[0211] According to the implementation scheme, the invention is further characterized by controlling the position of the intake throttle valve and / or exhaust tuning valve so as to actively transport heat from the source to the sensor to raise the temperature of the sensor to its desired operating temperature.

[0212] According to the present invention, a method includes: upon an engine start-up event, in response to detecting a deteriorated heating element of an oxygen sensor, operating a laser ignition source of an unburned engine and rotating an electrically driven intake compressor to transport heated cylinder gas to the sensor.

[0213] According to the implementation scheme, the heating element is configured to raise the temperature of the sensor, and both the heating element and the sensor can be positioned upstream or downstream of an emission control device located in the engine's exhaust system.

[0214] According to the embodiments, the invention is further characterized in that, when operating the laser ignition source, the cylinder of the engine is sealed, wherein the cylinder receives laser ignition energy from the laser ignition source; and the cylinder is unsealed to transport the heated cylinder gas to the sensor via rotating an electrically driven intake compressor.

[0215] According to the implementation scheme, opening the cylinder further includes positioning the cylinder such that both the intake valve and the exhaust valve connected to the cylinder are at least partially open.

[0216] According to the implementation scheme, the present invention is further characterized in that the laser ignition source is stopped after the cylinder is sealed, or the laser ignition source is maintained after the cylinder is unsealed, so as to transport the cylinder gas to the sensor.

[0217] According to the embodiment, the invention is further characterized in that an exhaust valve located in the exhaust valve passage is commanded to open, the exhaust valve being configured to deliver fluid flow around the turbine to transport heated cylinder gas to the sensor.

[0218] According to the implementation scheme, the invention is further characterized in that an exhaust recirculation valve located in the exhaust recirculation passage of the engine is ordered to close so as to transport the heated cylinder gas to the sensor.

[0219] According to the implementation scheme, the invention is further characterized by controlling the position of the intake throttle valve and / or exhaust tuning valve to transport the heated cylinder gas to the sensor.

[0220] According to the present invention, a system for a hybrid vehicle is provided, the system comprising: a controller having computer-readable instructions stored in a non-transitory memory, the computer-readable instructions, when executed, causing the controller to: activate an electric heat source under the condition of an engine start-up event in the event that the heating element of a heated exhaust oxygen sensor has deteriorated, and actively transport heat from the electric heat source to the heated exhaust oxygen sensor to increase the temperature of the heated exhaust oxygen sensor to its desired operating temperature, wherein actively transporting heat from the heat source to the heated exhaust oxygen sensor includes rotating the engine in a forward or reverse direction via a motor according to the position of the heated exhaust oxygen sensor having a deteriorated heating element and the electric heat source, without fuel being added.

[0221] According to the implementation scheme, the electric heat source also includes a heater connected to an emission control device located in the exhaust system of the engine, or one or more laser ignition devices configured to provide laser ignition energy to one or more cylinders of the engine.

[0222] According to the embodiments, the invention is further characterized by: an intake throttle valve; an exhaust tuning valve; and wherein the controller stores other instructions for controlling the position of one or more of the throttle valve and / or the exhaust tuning valve such that heat from an electric heating source is pressed near a heated exhaust oxygen sensor while avoiding unwanted pressure build-up in the engine.

[0223] According to an embodiment, the invention is further characterized by an electric supercharger located in the intake of the engine; and wherein the controller stores additional instructions for selecting to utilize the electric supercharger, which rotates via a motor in a forward or reverse direction, instead of the engine, to actively deliver heat from a heat source to a heated exhaust oxygen sensor.

Claims

1. A method for an engine, the method comprising: To reduce unwanted emissions during engine start-up events in a vehicle, under conditions where the temperature of a heated exhaust oxygen sensor is below its desired operating temperature and the heating element configured to heat the sensor has deteriorated, an alternative heat source is provided, and heat from the source is actively delivered to the sensor to raise its temperature to its desired operating temperature.

2. The method of claim 1, wherein the starting event of the engine includes a cold start event.

3. The method of claim 1, wherein the engine start-up event includes a start / stop event in which the temperature of the sensor has decreased below its desired operating temperature when the engine is not burning air and fuel.

4. The method of claim 1, wherein reducing undesirable emissions comprises reducing undesirable emissions at the start-up event compared to conditions where the heated exhaust oxygen sensor remains below its desired operating temperature at the start-up event.

5. The method of claim 1, wherein actively delivering heat from the source to the sensor comprises either rotating the engine in a forward or reverse direction without fuel or rotating an electric supercharger located in the engine's air intake in the forward or reverse direction, the forward or reverse direction being selected based on the position of the sensor relative to an emission control device located in the exhaust system of the engine of the vehicle and the alternative heat source.

6. The method of claim 5, further comprising, under the condition that the sensor is located upstream of the emission control device and the alternative heat source includes a heater configured to heat the emission control device, rotating the engine in reverse without fuel or rotating the electric supercharger in reverse; With the sensor positioned upstream of the emission control device and the alternative heat source including one or more laser ignition devices configured to provide laser ignition energy to one or more cylinders of the engine, the engine is rotated in the forward direction without fuel or the electric supercharger is rotated in the forward direction. as well as With the sensor positioned downstream of the emission control device and configured to heat the heater of the emission control device and / or one or both of the one or more laser ignition devices including the alternative heat source, the engine is rotated in the forward direction without fuel or the electric supercharger is rotated in the forward direction.

7. The method of claim 5, wherein actively delivering heat from the source to the sensor comprises selecting whether to use the engine in the forward or reverse direction compared to whether to use the electric supercharger in the forward or reverse direction, the selection being at least based on the state of charge of an onboard energy storage device that supplies power to a motor configured to rotate the engine and the electric supercharger in the forward or reverse direction.

8. The method of claim 1, further comprising controlling the position of an intake throttle valve and / or an exhaust tuning valve to actively deliver heat from the source to the sensor to raise the temperature of the sensor to its desired operating temperature.

9. A system for a hybrid vehicle, the system for a hybrid vehicle comprising: The controller has computer-readable instructions stored in non-transitory memory, which, when executed, cause the controller to: In the event of engine start-up, if the heating element of the heated exhaust oxygen sensor has deteriorated, an electric heat source is activated and heat from the electric heat source is actively delivered to the heated exhaust oxygen sensor to increase its temperature to its desired operating temperature. The active delivery of heat from the heat source to the heated exhaust oxygen sensor includes rotating the engine in a forward or reverse direction via a motor, depending on the location of the heated exhaust oxygen sensor with the deteriorated heating element and the electric heat source, without fuel being added.

10. The system of claim 9, wherein the electric heat source further comprises a heater connected to an emission control device located in the exhaust system of the engine.

11. The system of claim 9, wherein the electrothermal source further comprises one or more laser ignition devices configured to provide laser ignition energy to one or more cylinders of the engine.

12. The system of claim 9, wherein the starting event of the engine includes a cold start event.

13. The system of claim 9, wherein the engine start-up event includes a start / stop event in which the temperature of the heated exhaust oxygen sensor has decreased below its desired operating temperature when the engine is not burning air and fuel.

14. The system of claim 9, further comprising: Intake throttle body; Exhaust tuning valve; and The controller stores additional instructions for controlling the position of one or more of the throttle valve and / or the exhaust tuning valve such that heat from the heating source is trapped near the heated exhaust oxygen sensor, while avoiding unwanted pressure buildup in the engine.

15. The system of claim 9, further comprising an electric supercharger positioned in the air intake of the engine; and The controller stores additional instructions for the following operation: selecting to use the electric supercharger, which rotates via the motor in the forward or reverse direction, instead of the engine, to actively deliver heat from the heat source to the heated exhaust oxygen sensor.

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