System and method for mitigating gasoline particulate filter pressure sensor degradation

Abstract

The present disclosure provides "systems and methods to mitigate degradation of a gasoline particulate filter pressure sensor." Methods and systems are provided for regenerating a particulate filter positioned in an exhaust system of an engine of a vehicle. In one example, a method includes obtaining a first airflow in an air intake of the engine and obtaining a second airflow in the air intake of the engine, where regeneration of the particulate filter occurs in response to the first airflow differing from the second airflow by at least a threshold amount, where the first airflow and the second airflow comprise airflow delivered to the air intake of the engine from the exhaust system. In this way, the particulate filter can be regenerated in a condition where a load status of the particulate filter is unknown.

Description

Technical Field

[0001] This specification generally relates to methods and systems for controlling a vehicle engine to regenerate a gasoline particulate filter in the event of a deterioration of a differential pressure sensor connected to the gasoline particulate filter. Background Technology

[0002] In some direct-injection gasoline engines, a gasoline particulate filter (GPF) is included in the exhaust aftertreatment system to collect soot from the combustion process. A differential pressure sensor across the GPF is used to measure the pressure across the GPF, and if the differential pressure across the GPF exceeds a threshold, the GPF is regenerated via an onboard strategy. However, there may be modes in which the differential pressure sensor may be inaccurate (e.g., due to degradation). In such cases, determining the onboard strategy for when to regenerate the GPF can be challenging. Such a situation can lead to the GPF becoming clogged with soot, which can result in poor driving performance and increased exhaust tailpipe emissions. Therefore, a system and method are desired for determining the GPF's loading status in cases of differential pressure sensor degradation. Summary of the Invention

[0003] The inventors have recognized the aforementioned problems and expectations herein and have developed systems and methods to address them. In one example, a method includes regenerating a particulate filter located in the exhaust system of a vehicle's engine in response to a difference of at least a threshold amount between a first airflow in the engine's intake and a second airflow in the engine's intake, the airflow comprising airflow delivered from the exhaust system through the engine to the engine's intake. In this way, the particulate filter can be regenerated even when a differential pressure sensor determines that it is not operating as expected or anticipated. Such action can reduce engine degradation, improve emissions, and increase engine life.

[0004] In an example of this method, the first airflow may include a baseline intake airflow obtained under conditions where the particulate filter is known to be under load less than a threshold load. The second airflow may include a test intake airflow obtained under conditions where the differential pressure sensor coupled to the particulate filter is known to be degraded. Furthermore, in one example, the first and second airflows may be obtained by reversing the rotation of an unfueled engine, while in another example, they may be obtained by rotating an electrically powered booster positioned in the engine intake, and vice versa. For example, the particulate filter may include either a gasoline particulate filter or a diesel particulate filter.

[0005] The advantages and other advantages and features of this specification will become apparent from the following specific embodiments, either alone or in conjunction with the accompanying drawings.

[0006] It should be understood that the above summary provides a choice of concepts for presenting in a simplified form the concepts further described in the detailed embodiments. 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 embodiments. Furthermore, the claimed subject matter is not limited to implementations that address any shortcomings pointed out above or in any part of this disclosure. Attached Figure Description

[0007] Figure 1 An example vehicle propulsion system is illustrated schematically.

[0008] Figure 2 An example engine system with a fuel system and an evaporative emission system is illustrated schematically.

[0009] Figure 3 This illustration shows another example of an engine system that includes an electric booster.

[0010] Figures 4A to 4B An example H-bridge circuit is shown, which can be used to rotate a vehicle engine or electric compressor in a forward or reverse direction.

[0011] Figure 5 An advanced example method is shown for obtaining baseline airflow in the engine's intake system under substantially clean GPF conditions.

[0012] Figure 6 A high-level example method is shown for determining whether to regenerate the GPF in the event of a deteriorated GPF differential pressure sensor.

[0013] Figure 7 An example timeline is shown for obtaining baseline airflow by reversing the rotation of an unfueled engine.

[0014] Figure 8 An example timeline is shown for obtaining baseline airflow via an electrically operated booster positioned in the inlet in reverse operation.

[0015] Figure 9 An example timeline is shown for determining whether the GPF should be regenerated by reversing the rotation of an unfueled engine.

[0016] Figure 10 An example timeline is shown for determining whether to regenerate the GPF via a reverse-operated electric booster. Detailed Implementation

[0017] The following description relates to systems and methods for improving engine operation in vehicles having a gasoline particulate filter (GPF) or, in some examples, a diesel particulate filter (DPF) located in the engine's exhaust system. More specifically, improving engine operation may involve improving engine operation by activating a regeneration process for the GPF (or, in some examples, the DPF) in cases where a differential pressure sensor configured to indicate the load condition or limit level of the GPF deteriorates or otherwise malfunctions as expected. Activating the regeneration process in cases of differential pressure sensor deterioration may include delivering an airflow from the exhaust system to the engine intake, where the airflow in the engine intake is used to indicate the limit level of the GPF (or, in some examples, the DPF). This airflow delivery may include reversing the engine rotation, or may involve reversing an electric booster located in the engine intake. Thus, this delivery can be used in hybrid vehicles such as... Figure 1 This is performed in the hybrid vehicle system shown. Reversing the engine's rotation to direct airflow from the exhaust system to the engine intake can be achieved via engine systems such as... Figure 2 This can be accomplished by the engine system shown in the diagram. Alternatively, the airflow from the exhaust system to the engine intake can be delivered via an electric booster, such as through the engine system... Figure 3 The engine system shown here is used to accomplish this. Reversing the engine rotation or reversing the operation of the electric booster to direct airflow from the exhaust system to the engine intake may involve the use of an H-bridge circuit, such as... Figures 4A to 4B The H-bridge circuit is shown here. Determining the limiting level of the GPF (or in some examples, the DPF) may include first obtaining a baseline inlet flow measurement under conditions where the GPF is known to be substantially clean (e.g., less than 5% of the GPF / DPF capacity is loaded with soot and / or other particulate matter), and then, at a later time, when the differential pressure sensor indicates degradation, obtaining a test inlet flow measurement for comparison with the baseline inlet flow measurement. Therefore, Figure 5 The method for obtaining baseline intake airflow measurements is shown here, and Figure 6 The method for obtaining test inlet airflow measurements is shown here. Figure 7 The timeline for obtaining baseline intake airflow measurements by reversing engine rotation is shown below, and Figure 8 The timeline shown here is used to obtain baseline intake airflow measurements by reversing the rotation of the electric booster. Figure 9 The timeline for obtaining test intake airflow measurements by reversing the engine rotation is shown below, and Figure 10 The timeline shown here is used to obtain test intake airflow measurements by reversing the rotation of the electric booster.

[0018] Figure 1An example vehicle propulsion system 100 is shown. 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, while the motor 120 includes an electric motor. The motor 120 can be configured to utilize or consume a different energy source than the engine 110. For example, the engine 110 can consume liquid fuel (e.g., gasoline) to produce engine output, while the motor 120 can 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).

[0019] 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 fuel combustion at the engine is interrupted. For example, in a selected operating condition, when the engine 110 is deactivated, the motor 120 can propel the vehicle via the drive wheels 130 as indicated by arrow 122.

[0020] 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.

[0021] During certain 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, both engine 110 and motor 120 can be operated to propel the vehicle via drive wheels 130, as indicated by arrows 112 and 122, respectively. This configuration, in which both the engine and motor can selectively propel the vehicle, can be referred to as a parallel vehicle propulsion system. Note 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.

[0022] In other examples, the vehicle propulsion system 100 can be configured as a tandem vehicle propulsion system, whereby the engine does not directly propel the drive wheels. Instead, the engine 110 can be operated to power 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 the engine output into electrical energy, which can be stored in the energy storage device 150 for later use by the motor.

[0023] In some of the examples discussed in detail below, motor 120 can be used to turn or rotate engine 110 in an unfueled configuration. More specifically, motor 120 can use electricity from an on-board energy storage device 150 to rotate the unfueled engine, which may include, for example, a battery, capacitor, supercapacitor, etc. When using motor 120 to rotate the unfueled engine, fuel injection into the engine cylinders can be prevented, and no spark can be provided to each engine cylinder. As will be discussed further in detail below, in some examples, the engine can turn or rotate in the forward or default direction without fuel, while in other examples, the engine can turn or rotate in the reverse direction without fuel. For example, H-bridge circuit (see...) Figures 4A to 4B This can be used to rotate the engine in either the forward or reverse direction. Furthermore, although... Figure 1 Not shown (but see) Figure 3 In some examples, the vehicle propulsion system may include an electric booster or an electric compressor, which may similarly be controlled by a motor to rotate in a forward or reverse orientation.

[0024] 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 down (idle-stop) internal combustion engine 110 without receiving operational input to shut down the engine if selected idle-stop conditions, or in other words, a set of predetermined conditions, are met. These may include, for example, torque demand below a threshold engine speed, vehicle speed below a threshold vehicle speed (e.g., 5 mph), onboard energy storage being sufficiently charged, no request for air conditioning being received, etc. Similarly, the engine may automatically restart in response to torque demand exceeding 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 restart in response to an operator depressing the accelerator pedal after a certain duration of inactivity (e.g., at a traffic light). The engine can be started without fuel via a motor (e.g., 120) or an electric motor connected to the engine crankshaft until the desired engine speed is reached. Afterward, the motor or electric motor can be disabled, and fuel can be added to the engine. Thereafter, engine combustion can support engine rotation. Due to automatic start / stop, fuel consumption and exhaust emissions can be reduced.

[0025] Fuel system 140 may include one or more fuel storage tanks 144 for storing fuel in the vehicle. For example, fuel tank 144 may store one or more liquid fuels, including but not limited to gasoline, diesel, and alcohol fuels. In some examples, fuel may be stored in 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 may be supplied to engine 110 as indicated by arrow 142. Other suitable fuels or fuel mixtures may also be supplied to engine 110, which may be burned at the engine to produce engine output. 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.

[0026] In some examples, energy storage device 150 may be configured to store electrical energy that can be supplied to other electrical loads on 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, energy storage device 150 may include one or more batteries and / or capacitors.

[0027] 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 sensory 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 sensory feedback. The control system 190 can receive instructions from the vehicle driver 102 regarding driver requests for output to the vehicle's propulsion system. For example, the control system 190 can receive sensory feedback from a pedal position sensor 194 that communicates with pedal 192. Pedal 192 may 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), which receives a wireless signal 106 from a key fob 104 having a remote start button 105. In other examples (not shown), remote engine start can be initiated via a cellular phone or a 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.

[0028] Energy storage device 150 can periodically receive electrical energy from a power source 180 located 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 recharging operations of energy storage device 150 from power source 180, transmission cable 182 can electrically couple energy storage device 150 and power source 180. When the vehicle propulsion system is operated to propel the vehicle, transmission cable 182 can disconnect power source 180 from energy storage device 150. Control system 190 can identify and / or control the amount of electrical energy stored at the energy storage device, which may be referred to as state of charge (SOC).

[0029] In other examples, the power cable 182 may be omitted, and 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 should be understood that any suitable method can be used to recharge the energy storage device 150 from a power source that is not 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.

[0030] Fuel system 140 can periodically receive fuel from a fuel source outside the vehicle. As a non-limiting example, vehicle propulsion system 100 can be refueled by receiving fuel via fuel distribution device 170, as indicated by arrow 172. In some examples, fuel tank 144 can be configured to store fuel received from fuel distribution device 170 until it is supplied to engine 110 for combustion. In some examples, control system 190 can receive an indication of the fuel level stored in fuel tank 144 via a fuel level sensor. The fuel level stored in fuel tank 144 (e.g., identified by the fuel level sensor) can be communicated to the vehicle driver, for example, via a fuel gauge or indication in vehicle instrument panel 196.

[0031] The vehicle propulsion system 100 may also include an ambient temperature / humidity sensor 198 and roll stability control sensors, such as 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 therein for showing messages to the driver. The vehicle instrument panel 196 may also include various input elements for receiving driver input, such as buttons, touchscreens, voice input / recognition, etc. For example, the vehicle instrument panel 196 may include a fuel replenishment button 197, which can be manually actuated or pressed by the vehicle driver to initiate fuel replenishment. For example, in response to the vehicle driver actuating the fuel replenishment button 197, the fuel tank in the vehicle may depressurize, allowing fuel replenishment to be performed.

[0032] As is known in the art, control system 190 can communicatively couple to other vehicles or infrastructure using appropriate communication technologies. For example, control system 190 can couple to other vehicles or infrastructure via wireless network 131, which may include Wi-Fi, Bluetooth, some type of cellular service, wireless data transmission protocols, etc. 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 can be multi-hop. In some examples, longer-range communication (e.g., WiMax) can be used instead of V2V or V2I2V, or in combination with them, to extend the coverage area by several miles. In still other examples, vehicle control system 190 can communicatively couple to other vehicles or infrastructure via wireless network 131 and the Internet (e.g., cloud), as is known in the art.

[0033] Vehicle system 100 may also include an in-vehicle navigation system 132 (e.g., a Global Positioning System) that the vehicle driver can interact with. Navigation system 132 may include one or more position sensors to assist in estimating vehicle speed, vehicle altitude, vehicle position / location, etc. This information can be used to infer engine operating parameters, such as local atmospheric pressure. As discussed above, control system 190 may also be configured to receive information via the Internet or other communication networks. Information received from GPS can be cross-referenced with information obtained via the Internet to determine local weather conditions, local vehicle regulations, traffic information, etc. In one example, route learning methods can be combined with information received from GPS so that the vehicle control system 190 can learn the routes the vehicle typically travels. In some examples, other sensors 133 (e.g., lasers, radar, sonar, acoustic sensors, etc.) may be used additionally or optionally with the in-vehicle navigation system for route learning of the vehicle's typically traveled routes.

[0034] In some examples, vehicle system 100 may also include sensors specifically designed to indicate the occupancy status of the vehicle, such as seat load sensor 107, door sensing technology 108, and onboard camera 109.

[0035] Figure 2 A schematic illustration of vehicle system 206 is shown. It will be understood that vehicle system 206 may include... Figure 1 The vehicle system 206 is the same as the vehicle system 100 shown. 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... Figure 1 The fuel system 206 is the same as the fuel system 140 shown. The emission control system 251 includes a fuel vapor container or filter canister 222 for capturing and storing fuel vapor. In some examples, the vehicle system 206 may be a hybrid electric vehicle system.

[0036] 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 this example where the throttle valve is electronic, the power used to control the throttle valve to the desired position may be 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 located upstream of throttle valve 262. Engine exhaust system 225 includes exhaust manifold 248 leading to exhaust passage 235 for discharging exhaust gas to the atmosphere. The engine exhaust system 225 may include one or more emission control devices or exhaust catalysts 270, which may be mounted in a tightly connected location within the exhaust system. 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, 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 a signal to an electric heater actuator 256a to actuate the electric heater to turn it on or off.

[0037] It will be understood that other components, such as various valves and sensors, may be included in the engine. For example, an atmospheric pressure sensor 213 may be included in the engine intake. In one example, the atmospheric pressure sensor 213 may be a manifold air pressure (MAP) sensor and may be coupled downstream of the throttle valve 262 to the engine intake. The atmospheric pressure sensor 213 may rely on the partially open, fully open, or wide-open throttle valve condition (e.g., when the opening amount of the throttle valve 262 is greater than a threshold) to accurately determine the atmospheric pressure (BP). Alternatively, the MAP may be inferred from alternative engine operating conditions such as mass air flow rate (MAF), which is measured by the MAF sensor 210 coupled to the intake manifold.

[0038] 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 catalyzed wash coat, or a combination thereof. In some examples, during operation of the engine 110, the GPF 217 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 217, allowing the retained hydrocarbons and soot particles to be oxidized. Although Figure 2 GPF is shown here, but it is understood that in other examples, diesel particulate filters may alternatively be included in the vehicle propulsion system.

[0039] 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 be used to assess the pressure in the exhaust system. Pressure sensor 263 may be a differential pressure sensor located, for example, 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 for introducing air into the inlet of 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. Among other functions, soot sensor 268 can be used to diagnose the operation of GPF 217.

[0040] 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 connected to the above-mentioned fuel pump system 221. Figure 1 The fuel tank 218 is the same as the fuel tank 144 shown. The fuel pump system 221 may include one or more pumps for pressurizing fuel delivered to the injectors (such as the example 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-recirculating fuel system, a recirculating fuel system, or various other types of fuel systems. The fuel tank 220 may hold various fuel mixtures, including fuels with a range of alcohol concentrations, 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 shown, the fuel level sensor 234 may include a float connected to a variable resistor. Alternatively, other types of fuel level sensors may be used.

[0041] Before being flushed into the engine intake 223, the vapor generated in the fuel system 218 can be delivered to an evaporative emission control system 251, which includes a fuel vapor filter canister 222 via a vapor recovery line 231. The vapor recovery line 231 can be connected to the fuel tank 220 via one or more conduits and may include one or more valves for isolating the fuel tank during certain conditions. For example, the vapor recovery line 231 can be connected to the fuel tank 220 via one or more of conduits 271, 273, and 275, or a combination thereof.

[0042] In addition, in some examples, one or more fuel tank vent valves may be located in conduits 271, 273, or 275. Among other functions, the fuel tank vent valves may allow the fuel vapor filter of the emission control system to be maintained at a low pressure or vacuum without increasing the rate of fuel evaporation from the tank (which would otherwise occur when the fuel tank pressure decreases). For example, conduit 271 may include a slope vent valve (GVV) 287, conduit 273 may include a filler restrict vent valve (FLVV) 285, and conduit 275 may include a slope vent valve (GVV) 283. Furthermore, in some examples, a recovery line 231 may be coupled to a refueling system 219. In some examples, the refueling system may include a fuel tank cap 205 for sealing the refueling system to isolate it from the atmosphere. The refueling system 219 is coupled to the fuel tank 220 via a refueling pipe or neck 211.

[0043] Additionally, the fuel replenishment system 219 may include a fuel replenishment lock 245. In some examples, the fuel replenishment 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, preventing the fuel tank cap from being opened. For example, the fuel tank cap 205 may be held locked via the fuel replenishment lock 245 when the pressure or vacuum in the fuel tank is greater than a threshold. In response to a fuel replenishment request (e.g., a request initiated by the vehicle driver), the fuel tank may be depressurized, and the fuel tank cap may be unlocked after the pressure or vacuum in the fuel tank drops below a threshold. The fuel tank cap locking mechanism may be a latch or clutch that prevents the fuel tank cap from being removed when engaged. The latch or clutch may be electrically locked, for example via a solenoid, or may be mechanically locked, for example via a pressure diaphragm.

[0044] In some examples, the fuel replenishment lock 245 may be a filler valve located at the nozzle of the fuel filler pipe 211. In such examples, the fuel replenishment lock 245 may not prevent the removal of the fuel tank cap 205. Instead, the fuel replenishment lock 245 may prevent the fuel replenishment 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.

[0045] In some examples, the fuel filler lock 245 may be a fuel filler port lock, such as a latch or clutch, that locks a fuel filler port located in the body panel of the vehicle. The fuel filler port lock may be electrically locked, for example by a solenoid, or mechanically locked, for example by a pressure diaphragm.

[0046] In the example where the fuel supply lock 245 is locked using an electric mechanism, the fuel supply lock 245 can be unlocked by a command from the controller 212, for example, when the fuel tank pressure drops below a pressure threshold. In the example where the fuel supply lock 245 is locked using a mechanical mechanism, the fuel supply lock 245 can be unlocked via a pressure gradient, for example, when the fuel tank pressure drops below atmospheric pressure.

[0047] The emission control system 251 may include one or more emission control devices, 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, provided the fuel tank is connected to the filter canister under such conditions) during fuel tank refueling 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 ventilation line 227 that can deliver gases from the filter canister 222 to the atmosphere when storing or trapping fuel vapors from the fuel system 218.

[0048] The filter canister 222 may include a buffer 222a, and each of the filter canister and the buffer 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 it). 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 char). The buffer 222a may be positioned within the filter canister 222 such that during filter canister loading, fuel tank vapor is first adsorbed within the buffer, and then additional fuel tank vapor is adsorbed into the filter canister when the buffer is saturated. 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 filter canister buffer acts to suppress any fuel vapor surges flowing from the fuel tank to the filter canister, thereby reducing the likelihood of any fuel vapor surges entering the engine. One or more temperature sensors 232 may be coupled to and / or coupled within the filter canister 222. Heat is generated when fuel vapor is adsorbed by the adsorbent in the filter canister (heat of adsorption). Similarly, heat is consumed when fuel vapor is desorbed by the adsorbent in the filter canister. In this way, the adsorption and desorption of fuel vapor by the filter canister can be monitored and estimated based on the temperature changes inside the filter canister.

[0049] While flushing stored fuel vapor from fuel system 218 to engine intake port 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 vacuum from engine intake manifold 244 to fuel vapor filter canister for flushing. In some examples, ventilation line 227 may include air filter 259 disposed upstream of filter canister 222.

[0050] In some examples, the flow rate of air and vapor between the filter canister 222 and the atmosphere can be adjusted 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 within a duct 278 between the fuel tank and the fuel vapor filter canister 222. The FTIV 252 can be a normally closed valve, which, when open, allows fuel vapor to escape from the fuel tank 220 to the fuel vapor filter canister 222. The fuel vapor can then be escaped to the atmosphere or flushed into the engine intake system 223 via the filter canister flush valve 261. As will be discussed in detail below, in some examples, the FTIV may not be included, while in others it may be included.

[0051] 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 shown is the same control system. For example, the fuel system can operate in a fuel vapor storage mode (e.g., during fuel tank refueling operations and when the engine is not burning air and fuel), wherein the controller 212 can open the isolation valve 252 (if included) while closing the canister flush valve (CPV) 261 to direct the vapor of the refueling fuel into the canister 222, while preventing the fuel vapor from being directed into the intake manifold.

[0052] As another example, the fuel system can operate in a refueling mode (e.g., when the vehicle driver requests refueling from the fuel tank), where controller 212 can open isolation valve 252 (if included) while keeping canister flush valve 261 closed to depressurize the fuel tank before allowing fuel to be added. Therefore, isolation valve 252 (if included) can remain open during refueling operations to allow vapors of the refueling fuel to be stored in the canister. The isolation valve can be closed after refueling is complete.

[0053] As another example, the fuel system can operate in a filter canister flushing mode (e.g., after the emission control ignition temperature has been reached and the engine is burning air and fuel), where controller 212 can open filter canister flushing valve 261 when isolation valve 252 is closed (if included). Herein, the vacuum generated by the intake manifold of the operating engine can be used to draw fresh air through vent 227 and through fuel vapor filter canister 222 to flush the stored fuel vapor into intake manifold 244. In this mode, the flushed fuel vapor from the filter canister is burned in the engine. Flushing can continue until the amount of fuel vapor stored in the filter canister is below a threshold.

[0054] Controller 212 may form part of control system 214. As discussed, in some examples, control system 214 may be integrated with... Figure 1The control system 190 shown is identical. Control system 214 is shown receiving information from multiple sensors 216 (various examples of which are described herein) and sending control signals to multiple actuators 281 (various examples of which are 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 canister temperature sensor 232, a MAF sensor 210, an intake air temperature (IAT) sensor 257, and a pressure sensor 263 located upstream of the emission control unit 270. Sensors such as pressure sensors, temperature sensors, air-fuel ratio sensors, and other sensors that make up the sensor array 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 canister flush valve 261 and a canister vent valve 297, an electric heater actuator 256a, etc. The controller may receive input data from the various sensors, process the input data, and trigger the actuators in response to the processed input data based on instructions or codes programmed into one or more programs. This article is about Figures 5 to 6 Describe the example control program.

[0055] In some examples, the controller can be placed in a reduced-power mode or a sleep mode, where it maintains only basic functions and operates with lower battery consumption than the corresponding wake-up mode. For example, the controller can be placed in sleep mode after a vehicle-stopping event to perform diagnostic procedures 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 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 for diagnostics on the engine system, as will be discussed in further detail below.

[0056] Undesirable evaporative emissions (VEE) detection procedures can be performed intermittently by controller 212 on fuel system 218 and / or evaporative emissions system 251 to confirm the absence of VEEs in the fuel system and / or VEE system. Therefore, the VEE detection procedure can be performed during engine shutdown (engine shutdown test) using the engine shutdown natural vacuum (EONV) generated by temperature and pressure changes at the fuel tank after engine shutdown and / or a vacuum replenished from a vacuum pump. Alternatively, the VEE detection procedure 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 coupled 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 procedures. When included, CVV 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 from fuel vapor after passing through the filter canister to be expelled to the atmosphere. Similarly, during flushing operations (e.g., during filter canister regeneration and while the engine is running), the CVV can be opened to allow fresh air to flow in and strip fuel vapors stored in the filter canister. In some examples, CVV 297 can be a solenoid valve, where opening or closing of the valve is performed via actuation of the filter canister vent solenoid. Specifically, the filter canister vent valve can be open, closing 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 in the closed configuration, it latches to close without requiring additional current or voltage. For example, the valve can be closed with a 100ms pulse and then opened with another 100ms pulse at a later point in time. In this way, the battery power required to maintain the CVV closed is reduced.

[0057] The intake manifold 244 is connected to the combustion chamber or cylinder 230 via a series of intake valves 253. The combustion chamber is further connected to the exhaust manifold 248 via a series of exhaust valves 254. Although Figure 2 The diagram shows only one intake valve and one exhaust valve, but it will be understood that each combustion chamber or cylinder may include both an intake valve and an exhaust valve. In the illustrated 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 effluent from different combustion chambers to be directed to different locations within the engine system.

[0058] 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 or cam-actuated, the opening and closing timing of the exhaust and intake valves can be adjusted as needed to achieve desired combustion and emission control performance. Although the camshaft is not shown in this example diagram, one or more camshaft sensors (not shown) may be included in the vehicle propulsion system. Furthermore, the crankshaft 274 may include a crankshaft sensor 249. In some examples, one or both of the crankshaft sensor 249 and / or the camshaft sensor (not shown) may be used to infer the position of one or more pistons coupled to the engine cylinder 230.

[0059] In some examples, engine 110 may include a variable displacement engine (VDE) in which each cylinder of engine 110 can be selectively deactivated, where deactivation means the ability of controller 212 to command both the intake and exhaust valves of a particular cylinder to close, thereby sealing the particular cylinder. If fuel injection also stops, this action could cause the particular cylinder to essentially become an air spring if the engine is running. Thus, as shown herein, in one embodiment, deactivation of intake valve 253 may be controlled by a first VDE actuator 276, while 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 may deactivate multiple cylinders (both intake and exhaust valves), for example, all cylinders in a cylinder bank, or a different actuator may control the deactivation of all intake valves, while another different actuator controls the deactivation of all exhaust valves of the deactivated cylinders in the cylinder bank. It will be understood that if the cylinder is a non-disengaged cylinder of a VDE engine, then the cylinder may not have any valve deactivation actuators. It will also be understood that although engine 110 is shown as a VDE engine, in other examples the engine may not be a VDE engine without departing from the scope of this disclosure.

[0060] In some examples, vehicle system 206 may be a hybrid vehicle having multiple torque sources available for one or more wheels 236 (e.g., 130). In the example shown, 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. When one or more clutches 246 are engaged, the crankshaft 274 of engine 110 and electric motor 241 are connected to the wheels 236 via transmission 243. In the example shown, a first clutch is located between crankshaft 274 and electric motor 241, and a second clutch is located between electric motor 241 and transmission 243. Controller 212 may send signals to the actuator (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 electric motor 241, and / or connecting or disconnecting electric motor 241 from transmission 243 and components connected to transmission 243. Transmission 243 may be a gearbox, a planetary gear system, or another type of transmission. The powertrain can be configured in various ways, including parallel, series, or series-parallel hybrid vehicles.

[0061] Motor 241 receives power from traction battery 247 (e.g., 150) to provide torque to wheel 130. Motor 241 can also operate as a generator to provide power to charge traction battery 247, for example, during braking operations.

[0062] Turn now Figure 3 The illustration shows another example engine system 308. Without departing from the scope of this disclosure, engine system 308 may be included in vehicle propulsion system 206 (e.g., 100). It will be understood that many components of engine system 308 may also be included in engine system 206. Engine 310 (e.g., 110) includes engine intake system 362 (e.g., 223) and 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 illustrated embodiment, engine 310 is a turbocharged engine coupled to turbocharger 315, which includes compressor 314 driven by turbine 316. Specifically, fresh air is introduced into engine 310 via air purifier 312 (e.g., 215) along intake passage 342 (e.g., 242) and flows to compressor 314. The compressor may be a suitable intake compressor, such as a motor-driven or drive shaft-driven supercharger compressor. In engine system 310, the compressor is a turbocharger compressor, which is mechanically connected to turbine 316 via shaft 319. Turbine 316 is driven by expanding engine exhaust.

[0063] like Figure 3As shown, compressor 314 is connected to throttle body 320 (e.g., 262) via supercharged air cooler (CAC) 318. Throttle body 320 is connected to engine intake manifold 322 (e.g., 244). Compressed intake air flows from compressor through supercharged air cooler 318 and throttle body 320 to reach intake manifold 322. Figure 3 In the illustrated embodiment, the pressure of the intake air within the intake manifold 322 is sensed by a manifold air pressure (MAP) sensor 324 (e.g., 213). In some examples, the airflow in the intake manifold may be sensed via a mass air flow (MAF) sensor 321 (e.g., 210). The temperature of the ambient air entering the intake passage 342 may be estimated via an intake air temperature (IAT) sensor 351 (e.g., 257).

[0064] One or more sensors may be connected to the inlet of compressor 314. For example, temperature sensor 358 may be connected to the inlet to estimate compressor inlet temperature, and pressure sensor 356 may be connected to the inlet to estimate compressor inlet pressure. As another example, ambient humidity sensor 357 may be connected to the inlet to estimate the humidity of the intake 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 (such as humidity, temperature, pressure, etc.) may be inferred based on engine operating conditions. Furthermore, when exhaust gas recirculation (EGR) is enabled, the sensors may estimate the temperature, pressure, humidity, and air-fuel ratio of the intake air mixture, which includes fresh air, recirculated compressed air, and residual exhaust gas received at the compressor inlet.

[0065] The wastegate actuator 392 can be actuated to open the wastegate 391 to release at least some exhaust pressure from upstream of the turbine to a downstream position 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 actuable to open and close; however, it is recognized herein that in some examples, a spring-loaded wastegate may be included in the vehicle system.

[0066] 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. Electric supercharger 355 can be powered via an onboard energy storage device (e.g., 150), which may include a battery, capacitor, supercapacitor, 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).

[0067] In one example, the electric booster 355 can be actuated in response to the increased wheel torque demand to rapidly provide the desired boost air to the engine during turbocharger acceleration. Thus, the increased torque can be met without causing turbo lag, which could otherwise occur if the assistance from the electric booster is unavailable. In such an example, the electric booster 355 can be actuated to turn off or deactivate in response to the turbocharger accelerating to a threshold speed (e.g., 70,000 rpm). More specifically, the operation of the electric booster 355 can be controlled based on command signals (e.g., duty cycle or pulse width signals) received from a vehicle controller (e.g., controller 212). For example, the controller can signal the electric booster actuator 355b to actuate the electric booster to turn on. In another example, the controller can signal the electric booster actuator 355b to actuate the electric booster to turn 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 rotate in the reverse direction. The reverse operation of the electric booster 355 may be achieved at least partially via an H-bridge circuit (see [link to relevant documentation]). Figures 4A to 4B ).

[0068] An electric compressor 355 can be positioned between a first electric compressor conduit 359a and a second electric compressor conduit 359b. The first electric compressor conduit 359a fluidly connects an intake passage 342 to the electric compressor 355 upstream of an electric compressor bypass valve 361. The second electric compressor conduit 359b fluidly connects the electric compressor 355 to an intake passage 342 downstream of an electric compressor bypass valve 361. As an example, air can be drawn into the electric compressor 355 via the first electric compressor conduit 359a upstream of the electric compressor bypass valve 361, and compressed air can exit the electric compressor 355 and be delivered via the second electric compressor conduit to the intake passage 342 downstream of the electric compressor bypass valve 361. In this way, compressed air can be delivered to the engine intake manifold 322. It is understood that the above description relates to when the electric compressor is rotating in the forward direction. In some examples, the electric compressor can rotate in the opposite direction, which can thus cause compressed air to be delivered in the opposite direction, in other words, from the intake manifold (and in some examples the exhaust system) via intake passage 342 to the atmosphere.

[0069] When the electric booster 355 is activated to provide boost more quickly than relying solely on the turbocharger 315, it is understood that when the electric booster 355 is activated, the electric booster bypass valve 361 can be commanded to close. In this way, intake air can flow through the turbocharger 315 and through the electric booster 355. Once the turbocharger reaches its threshold speed, the electric booster 355 can be shut off, and the electric booster bypass valve 361 can be commanded to open.

[0070] 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 also connected to exhaust manifold 336 (e.g., 248) via a series of exhaust valves 354 (e.g., 254). In the illustrated 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.

[0071] 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 or cam-actuated, the timing of the opening and closing of the exhaust valve and intake valve can be adjusted as needed to achieve desired combustion and emission control performance. Although the camshaft is not shown in this example diagram, 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, one or both of the crankshaft sensor and / or camshaft sensor may be used to infer the position of one or more pistons coupled to engine cylinder 330 (e.g., 230).

[0072] In some examples, engine 310 may include a variable displacement engine (VDE) in which each cylinder of engine 310 can be selectively deactivated, where deactivation means the ability of controller 212 to command both the intake and exhaust valves of a particular cylinder to close, thereby sealing the particular cylinder. If fuel injection also stops, this action could cause the particular cylinder to essentially become an air spring if the engine is running. Thus, as shown herein, in one embodiment, deactivation of intake valve 353 may be controlled by a first VDE actuator 376 (e.g., 276), while deactivation of exhaust valve 354 may be controlled by a second VDE actuator 377. In alternative embodiments, a single VDE actuator may control the deactivation of both the intake and exhaust valves of the deactivatable cylinder. In other embodiments, a single cylinder valve actuator can deactivate multiple cylinders (both intake and exhaust valves), for example, all cylinders in a cylinder bank, or a different actuator can control the deactivation of all intake valves, while another different actuator controls the deactivation of all exhaust valves of the deactivated cylinders in the cylinder bank. It will be understood that if the cylinder is a non-deactivatable cylinder in a VDE engine, then the cylinder may not have any valve deactivation actuators.

[0073] Combustion chamber 330 may be supplied with one or more fuels, such as gasoline, alcohol-fuel mixtures, diesel, biodiesel, compressed natural gas, etc., via injector 366 (e.g., 266). Fuel may be supplied to the combustion chamber via direct injection, port injection, throttle body injection, or any combination thereof. Combustion may be initiated in the combustion chamber via spark ignition and / or compression ignition.

[0074] like Figure 3 As shown, exhaust gas from one or more exhaust manifold sections can be directed to turbine 316 to drive the turbine. The flow from the combination of 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, thereby reducing the amount of one or more substances in the exhaust stream. For example, exhaust aftertreatment device 370 may be configured to capture NO from the exhaust stream when the exhaust stream is lean. x Furthermore, when the exhaust flow is rich, the amount of NO captured decreases. x In other examples, the exhaust aftertreatment device 370 can be configured to cause NO to... x Disproportionate or selective reduction of NO by means of reducing agent xIn 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 such functionality may be arranged individually or together in the coating 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, 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, which may send a signal to the electric heater actuator 327a to actuate the electric heater to turn it on or off.

[0075] 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 washer 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, thereby oxidizing retained hydrocarbons and soot particles.

[0076] In some examples, temperature sensor 367a (e.g., 226) may be located upstream of the inlet of GPF 364, and temperature sensor 367b (e.g., 229) may 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) may be used to assess the pressure in the exhaust system. For example, pressure sensor 365 may be a differential pressure sensor located upstream (closer to the exhaust manifold) and downstream (farther 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 for introducing air into the inlet of GPF 364 for regeneration. Additionally, in some examples, a soot sensor may be located downstream of GPF 364 to assess the level of soot released from GPF 364.

[0077] Exhaust gas recirculation (EGR) delivery passage 380 may be coupled to exhaust passage 304 (e.g., 235) upstream of turbine 316 to provide high-pressure EGR (HP-EGR) to the engine intake manifold downstream of compressor 314. EGR valve 352 may be coupled to EGR passage 380 at the junction of EGR passage 380 and intake passage 342. EGR valve 352 may be opened to allow a controlled amount of exhaust gas to enter the compressor outlet to achieve desired combustion and emission control performance. EGR valve 352 may be configured as a continuously variable valve or an on / off valve. In another embodiment, the engine system may additionally or optionally include a low-pressure EGR (LP-EGR) flow path, wherein exhaust gas is drawn downstream of turbine 316 and recirculated to the engine flow path intake manifold upstream of compressor 314.

[0078] One or more sensors can be coupled to EGR channel 380 to provide details about the composition and condition 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 water content of the EGR, and an air-fuel ratio sensor (not shown) can be provided to estimate the air-fuel ratio of the EGR. Optionally, the EGR condition can be inferred from one or more temperature sensors, pressure sensors, humidity sensors, and air-fuel ratio sensors coupled to the compressor inlet.

[0079] Multiple sensors, including exhaust temperature sensor 328 (e.g., 233), exhaust sensor 326 (e.g., 237), and exhaust pressure sensor 329, can be connected to the main exhaust passage 304. The exhaust sensors can be linear oxygen sensors or UEGO (universal or wide-range exhaust oxygen), dual-state oxygen sensors or EGO, HEGO (heated EGO), NOx, HC, or CO sensors.

[0080] Engine system 308 may also include control system 214, as discussed above. Control system 214 is shown as receiving information from multiple sensors 216 (various examples of which are described herein) and sending control signals to multiple actuators 218 (various examples of which are described herein). As an example, sensors 216 may include exhaust gas sensor 326, 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.

[0081] Actuator 281 may include, for example, an electric booster bypass valve 361, a throttle valve 320, an electric booster actuator 355b, an EGR valve 352, an exhaust valve actuator 392, 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 programs.

[0082] Furthermore, similar to engine system 208, engine system 308 can be a hybrid vehicle having multiple torque sources available for one or more wheels 130. For example, vehicle system 308 may include electric motor 341, also referred to as a motor or motor / generator. When one or more clutches 346 (e.g., 246) are engaged, crankshaft 374 (e.g., 274) may connect engine 310 and electric motor to wheel 331 (e.g., 130) via transmission 343 (e.g., 243). Electric motor 341 (e.g., 241 or 120) may receive power from traction battery 347 (e.g., 247 or 150), as discussed above. Crankshaft 374 may include crankshaft sensor 349 (e.g., 249).

[0083] Furthermore, engine system 308 can be connected to evaporative emission system via filter flushing valve (CPV) 394 (e.g., 261). Figure 3 Not shown, but see [link / reference]. Figure 2 (of 251). Although Figure 3 Details of the evaporative emission system and fuel system are not shown, but it can be understood that the components of such systems are similar to those described above. Figure 2 The components shown here are the same.

[0084] Figure 4A and Figure 4BAn example circuit 400 is shown that can be used to reverse the rotational orientation of an electric motor (e.g., 120). This circuit can be used to rotate an engine (e.g., 110) in a forward direction (e.g., the same direction as when the engine is operating to burn air and fuel) or in a reverse direction, and / or can be used to rotate an electric compressor (e.g., 355) in a forward direction (e.g., when compressed air is being supplied to the engine and exhaust system) or in a reverse direction. Thus, circuit 400 schematically illustrates an H-bridge circuit that can be used to operate motors 410 (e.g., 120 and / or 241, 341) in a first (forward) direction and alternately in a second (reverse) direction. Circuit 400 includes a first (LO) side 420 and a second (HI) side 430. Side 420 includes transistors 421 and 422, while side 430 includes transistors 431 and 432. Circuit 400 also includes a power supply 440.

[0085] exist Figure 4A In this configuration, transistors 421 and 432 are activated (energized), while transistors 422 and 431 are deactivated. In this configuration, the left lead 451 of motor 410 is connected to power supply 440, and the right lead 452 of motor 410 is connected to ground. In this way, motor 400 can operate in the forward (default) direction. When the engine is operated in the forward direction via the motor, the engine can be in a rotation start mode to initiate initial combustion. 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 to drive the vehicle. It is understood that in some examples, the engine can rotate in the forward (e.g., default) direction while the vehicle is stationary, and it is desirable for the engine to rotate or spin in the forward direction without combustion.

[0086] exist Figure 4B In this configuration, transistors 422 and 431 are activated (energized), while transistors 421 and 432 are deactivated. In this configuration, the right lead 452 of motor 410 is connected to power supply 440, and the left lead 451 of motor 410 is connected to ground. In this way, motor 410 can operate in the reverse direction.

[0087] The above is about Figures 1 to 4BThe described system can thus realize a system for a hybrid vehicle, comprising: an engine including an intake port and an exhaust system; a particulate filter located in the exhaust system, the particulate filter including a differential pressure sensor configured to indicate the load state of the particulate filter; and an electric motor capable of rotating an unfueled engine. Such a system may further include: a mass airflow sensor located in the engine intake port; and a throttle valve located in the engine intake port. Such a system may also include a controller having computer-readable instructions stored in a non-transitory memory, which, when executed, cause the controller to: in response to an indication or determination that the load state of the particulate filter is below a predetermined threshold load state, deliver a first airflow from the exhaust system to the engine intake port and record a baseline intake airflow via the mass airflow sensor. The controller can store additional instructions for the following operations: at a later time, in cases indicating differential pressure sensor degradation and when the particulate filter load is independent of the differential pressure sensor reading, to deliver a second airflow from the exhaust system to the engine intake and record the test intake airflow via a mass airflow sensor. Delivering the first and second airflows may include commanding the throttle to fully open. The controller can also store additional instructions for the following operations: in response to a difference of at least a threshold amount between the baseline intake airflow and the test intake airflow, to initiate a particulate filter regeneration process.

[0088] In such a system, the controller can store additional instructions for the following operations: delivering a first airflow and delivering a second airflow by rotating an unfueled engine via a motor.

[0089] In such a system, the system may further include: an electric booster located in the engine's intake port, upstream of the throttle valve; an exhaust gas recirculation valve located in an exhaust gas recirculation passage connecting the exhaust system to the engine's intake port; and a wastegate located in a wastegate passage in the exhaust system. The wastegate passage may be configured to deliver fluid flow around a turbine located in the exhaust system. Such a system may further include: an electric booster bypass valve located in the engine's intake port, upstream of the throttle valve; and a variable displacement engine actuator for sealing engine cylinders. In such a system, the controller may store additional instructions for delivering a first airflow and a second airflow via reverse operation of the electric booster, wherein the exhaust gas recirculation valve is commanded to open, the wastegate is commanded to open, the electric booster bypass valve is commanded to close, and the engine cylinders are sealed.

[0090] In such a system, the system may further include one or more seat load sensors, door sensing technology and / or onboard cameras. In such a system, the controller may store additional instructions for delivering a first airflow and a second airflow when indicating that the hybrid vehicle is not occupied, wherein the occupancy status is indicated via one or more of the seat load sensors, door sensing technology and / or onboard cameras.

[0091] Turn now Figure 5 A high-level flowchart of an example method 500 for obtaining baseline intake airflow measurements to determine whether to regenerate the GPF is shown. More specifically, method 500 can be used under conditions where the GPF is known to be substantially clean (e.g., below a threshold soot load level, which may include 10% or less, 5% or less, etc.) to obtain baseline intake airflow measurements that vary with the limit level of the intake filter located upstream of the intake throttle valve. For example, whether the GPF is substantially clean can be determined by a controller based on the pressure across the GPF, which is monitored, for example, via differential pressure sensors (e.g., 263, 365). The baseline intake airflow measurements can be obtained by reversing the rotation of an unfueled engine and recording the intake airflow measurements via MAF sensors (e.g., 210, 321).

[0092] The references described in this article and Figures 1 to 4B The system illustrated herein is used to describe method 500; however, it will be understood that method 500 can be applied to other systems without departing from the scope of this disclosure. Instructions for performing method 500 and the remaining methods included herein can be provided by a controller such as... Figure 2 The controller 212 is based on instructions stored in non-transitory memory and combined with information from sensors in the engine system (such as temperature sensors, pressure sensors, and the reference above). Figures 1 to 4B The controller may use signals received from other sensors described herein to perform the operation. According to the methods described herein, the controller may employ actuators such as motors / generators (e.g., 241 or 341), throttle valves (e.g., 262 or 320), fuel injectors (e.g., 266 or 366), electric boosters (e.g., 355), EGR valves (e.g., 352), exhaust valve actuators (e.g., 392), electric booster bypass valves (e.g., 361), etc.

[0093] Method 500 begins at 505 and may include estimated operating conditions. Operating conditions may be estimated, measured, and / or inferred, and operating conditions 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, atmospheric pressure, etc.).

[0094] At step 510, method 500 may include indicating whether conditions for obtaining a baseline intake airflow measurement are met, which varies with the limitation level of the intake filter (e.g., 215). Conditions met at 510 may include indicating or determining via the controller that the GPF has been regenerated within a threshold duration prior to method 500. The threshold duration may include 24 hours or less, 12 hours or less, 8 hours or less, 6 hours or less, 4 hours or less, etc. In other words, in response to the determination that GPF regeneration has been completed via an onboard strategy (e.g., under the control of the vehicle controller), diagnostics for obtaining the baseline intake airflow measurement may be planned such that such action can be initiated when it is determined that the conditions for obtaining the baseline intake airflow measurement are met.

[0095] At point 510, the satisfied condition may further include a remote start event indicated or determined by the controller, wherein the vehicle is indicated as not being occupied. This determination may be made via, for example, a seat load sensor (e.g., 107), door sensing technology (e.g., 108), or an onboard camera (e.g., 109). In another example, the satisfied condition may include an indication or determination by the controller that the vehicle is autonomously operating, wherein similarly, the indication / determination that the vehicle is not occupied is made. In yet another example, the satisfied condition may include a planned wake-up of the vehicle controller at a time following a vehicle ignition shutdown event, wherein further indication / determination that the vehicle is not occupied is made.

[0096] At 510, the conditions may also include indicating or determining via the controller that the MAF sensor (e.g., 210, 321) positioned in the engine intake is operating as desired or anticipated.

[0097] If at 510 there is no indication / determination that the conditions for obtaining the baseline intake airflow measurement are met, then method 500 may proceed to 515. At 515, method 500 may include maintaining the current vehicle operating parameters. For example, if the vehicle is operating, then such vehicle operation may be maintained. If the vehicle is not operating, then such vehicle operating state may be maintained. It is understood that the vehicle operating parameters may be maintained until it is indicated / determination that the conditions for obtaining the baseline intake airflow measurement are met.

[0098] Returning to 510, in response to determining that the conditions for obtaining baseline intake airflow measurements are met, method 500 can proceed to 520. At 520, method 500 may include delivering airflow from the exhaust system to the engine intake. In one example, delivering airflow from the exhaust system to the engine intake may include reversing the engine without fuel. More specifically, a motor (e.g., 241) may be actuated via a controller (e.g., 212) to reverse the engine (e.g., 110). To reverse the engine via the motor, an H-bridge circuit, as discussed above, may be utilized. The engine may be reversed at a predetermined speed (e.g., predetermined RPM).

[0099] Although not explicitly shown, directing airflow from the exhaust system to the engine intake via reversing the rotation of an unfueled engine can include commanding the intake throttle valve to fully open (e.g., 262, 320). In examples where an electric booster bypass valve (e.g., 361) is included in the engine system, the electric booster bypass valve can be additionally commanded to open. For vehicles equipped with an EGR passage (e.g., 380), in situations where directing airflow from the exhaust system to the engine intake involves reversing the rotation of an unfueled engine, the EGR valve (e.g., 352) can be commanded or kept closed. Furthermore, in this case, the exhaust valve (e.g., 391) can be commanded to open to deliver airflow around the turbine (e.g., 316). However, in other examples, without departing from the scope of this disclosure, the exhaust valve can be commanded to open without reversing the operation of the unfueled engine. In other examples, the exhaust valve may not be included in the vehicle system (see, for example...). Figure 2 ).

[0100] In another example, instead of reversing the rotation of an unfueled engine to direct airflow from the exhaust system to the engine intake, an electric booster (e.g., 355) can be used to draw airflow from the exhaust system into the engine intake. To draw airflow from the exhaust system into the engine intake, the electric booster can operate in reverse, similar to engine reversal. In this case, the electric booster bypass valve (e.g., 361) can be commanded or maintained closed, the throttle valve (e.g., 320) can be actuated fully open, engine cylinder seals can be actuated, the EGR valve can be actuated open, and the wastegate valve can be actuated open. Sealing the engine cylinder can include actuating the intake and exhaust valves to close, for example, by sending a signal via a controller to the VDE actuators (e.g., 376, 377) to actuate the intake and exhaust valves of the engine cylinders to a closed configuration. In this way, the electric booster can draw air from the exhaust system into the engine intake to bypass the engine and turbine via the open EGR valve and the open wastegate valve.

[0101] In an example where the electric booster is not included in the vehicle system, it can be understood that delivering airflow from the exhaust system to the engine intake is done by reversing the rotation of the unfueled engine. However, in cases where the vehicle system includes an electric booster, reversing the electric booster to obtain baseline airflow may be more energy-efficient, as the turbocharger and engine can be bypassed, as discussed. Therefore, the vehicle controller can determine whether to reverse the engine or, in the case of an electric booster in the vehicle system, utilize the electric booster to deliver airflow from the exhaust system to the engine intake based on battery charge, fuel level in the fuel tank, learned driving procedures, etc.

[0102] Regardless of which method is selected by the controller to deliver air from the exhaust system to the engine intake, method 500 can proceed to 525 in response to delivering airflow from the exhaust system to the engine intake. At 525, method 500 may include obtaining a mass airflow (MAF) reading for a predetermined duration while the engine is being rotated without fuel. The MAF reading may be transmitted to the controller and may be obtained periodically, such as every 1 to 2 seconds, every 5 seconds, every 10 seconds, etc. It is understood that the MAF reading may be obtained via an MAF sensor positioned in the engine intake (e.g., 321). The predetermined duration may include a duration for which the MAF can be determined with high confidence.

[0103] In response to the elapsed predetermined time, method 500 may proceed to 530. At 530, method 500 may include processing the MAF data obtained at step 525 and storing the processed MAF data at the controller. For example, processing the MAF data at 530 may include averaging all the MAF data obtained at 525 to obtain a high-confidence MAF determination.

[0104] With the MAF data processed and stored at the controller, method 500 can proceed to 535. At 535, method 500 may include stopping the delivery of airflow from the exhaust system to the engine intake. For example, if delivering the airflow involves reversing the rotation of an unfueled engine, then the engine reversing can be stopped. Alternatively, if airflow is delivered from the exhaust system to the engine intake using an electric booster, the electric booster can be stopped from reversing. Furthermore, any valves actuated to open / close for delivery can return to their initial state. For example, if the engine is reversed to deliver airflow from the exhaust system to the engine intake, the electric booster bypass valve can be commanded to close and the throttle valve can be returned to its position before delivery. Alternatively, if airflow is delivered from the exhaust system to the engine intake using an electric booster, engine cylinders can be opened, the wastegate and EGR valve can be commanded to close, and the throttle valve can be returned to its position before delivery.

[0105] Method 500 can end once the baseline intake airflow measurement is obtained and stored at the controller.

[0106] It is understandable that the baseline intake airflow measurement compensates for the current state of the intake filter. In other words, the variable airflow in the engine intake port changes to the state of the intake filter in the case of the most recent GPF cleaning before the baseline intake airflow measurement was obtained. Therefore, the baseline intake airflow measurement obtained via method 500 takes into account the current state of the intake filter (e.g., more or less clogging).

[0107] However, the condition of the intake filter may change after the baseline intake airflow measurement is obtained. Therefore, the baseline intake airflow measurement can be "aged" based on models that infer or estimate dust intake conditions through the intake via the intake filter over engine operating time. In other words, the longer the engine operates before another baseline intake airflow measurement, the more likely the intake filter is to be loaded (e.g., loaded with dust, insects, etc.). Therefore, the model can accurately predict the current load condition of the intake filter at any time after the baseline intake airflow measurement has been obtained, and if the GPF is clean, this baseline intake airflow measurement can be used to estimate or infer the expected MAF (Maximum Airflow Rate). This estimate can then be compared with the actual measured MAF (see below). Figure 6 (As discussed in the text) comparisons are made to indicate / determine the degree of soot load on the GPF. It is understood that the current load status of the intake filter can be updated periodically (e.g., at predetermined time intervals) via the model to accurately reflect the current intake filter load status.

[0108] Therefore, now turn to Figure 6 A high-level flowchart of an example method 600 for determining the load state of a GPF when a condition indicates that the GPF differential pressure sensor (e.g., 263, 365) is deteriorating or otherwise not operating as expected or anticipated is presented. In this case, the load state of the GPF may be independent of the readings provided via the GPF differential pressure sensor. In other words, the load state of the GPF may be unknown in such a condition, or known to be below a threshold non-zero determinism level. More specifically, in cases indicating that the GPF differential pressure sensor is not operating as expected or anticipated, Figure 6 The alternative method shown can be used to determine whether to regenerate the GPF based on the indicated load condition of the GPF.

[0109] The references described in this article and Figures 1 to 4B The system illustrated herein is used to describe method 600; however, it will be understood that method 600 can be applied to other systems without departing from the scope of this disclosure. Instructions for performing method 600 and the remaining methods included herein can be provided by a controller such as... Figure 2 The controller 212 is based on instructions stored in non-transitory memory and combined with information from sensors in the engine system (such as temperature sensors, pressure sensors, and the reference above). Figures 1 to 4B The controller may use signals received from other sensors described herein to perform the operation. According to the methods described herein, the controller may employ actuators such as motors / generators (e.g., 241 or 341), throttle valves (e.g., 262 or 320), fuel injectors (e.g., 266 or 366), electric boosters (e.g., 355), EGR valves (e.g., 352), exhaust valve actuators (e.g., 392), electric booster bypass valves (e.g., 361), etc.

[0110] Method 600 begins at 605 and may include estimated operating conditions. Operating conditions may be estimated, measured, and / or inferred, and operating conditions 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, atmospheric pressure, etc.).

[0111] Proceeding to 610, method 600 may include indicating or determining, via the controller, whether to indicate that the GPF differential pressure sensor is deteriorating. For example, circuit codes or other sensor validity codes may be communicated to / via the controller to indicate / determine that the GPF sensor is not operating as expected or anticipated. In the absence of such indication of GPF sensor deterioration or malfunction, method 600 may proceed to 615. At 615, method 600 may include maintaining current vehicle operating parameters. For example, if the vehicle is operating, propelled by an engine, an electric motor, or some combination of both, then this operation may be maintained. In another example, if the engine is not operating, then this vehicle state may be maintained. Method 600 may then terminate.

[0112] Returning to 610, in response to indicating / determining deterioration of the GPF differential pressure sensor, method 600 can proceed to 620. At 620, method 600 may include indicating / determining whether conditions for determining a GPF limit level, or in other words, the GPF load condition (e.g., soot load level), are met. More specifically, since the GPF differential pressure sensor is not operating as expected, alternative methods can be used to determine whether GPF regeneration is desired.

[0113] The conditions satisfied at 620 may be similar to those in step 510 of method 500 regarding obtaining baseline intake airflow measurements that vary with the limit level of the intake filter (e.g., 215). More specifically, the conditions satisfied at 620 may include an indication that baseline intake airflow measurements have been previously obtained according to method 500. The conditions satisfied at 620 may also include an indication / determination that the MAF sensor located in the engine intake port is operating as desired. The conditions satisfied at 620 may also include an indication / determination that no engine system degradation that could affect the determination of GPF particulate load has occurred due to the acquisition of baseline intake airflow measurements. More specifically, the conditions satisfied at 620 may include an indication or determination that one or more of the throttle valve, exhaust valve, EGR valve, VDE actuator, electric booster bypass valve, etc., are operating as desired or anticipated.

[0114] The condition satisfied at 620 may also include an indication / determination of remote start, wherein the vehicle is not occupied. In another example, the condition satisfied at 620 may include an indication / determination of the vehicle including an autonomous vehicle, wherein the vehicle is not occupied. The condition satisfied at 620 may additionally or optionally include an indication / determination that the vehicle controller has been awakened from hibernation mode (specifically for diagnostic purposes to determine GPF limits) after a specified time since the ignition shutdown event.

[0115] If at 620 the conditions for determining the GPF limit level have not yet been indicated / determined, then method 600 may proceed to 625. At 625, method 600 may include maintaining the current vehicle operating parameters, and may also include planning diagnostics via the controller when the next potential opportunity arises where the conditions for performing diagnostics to determine the GPF limit level are met.

[0116] In response to an indication that the conditions for diagnostics are met, method 600 may proceed to 630. At 630, method 600 may include delivering airflow from the exhaust system to the engine intake.

[0117] Similar to step 520 of method 500, at 630, method 600 may include delivering airflow from the exhaust system to the engine intake port by reversing the engine without fuel. As discussed, the engine (e.g., 110) may be reversed by a motor (e.g., 241) actuated via a controller (e.g., 212). To reverse the engine via the motor, an H-bridge circuit, as discussed above, may be utilized. The engine may be reversed at a predetermined speed (e.g., predetermined RPM). The predetermined speed may include the same predetermined speed as when reversing the engine without fuel to obtain baseline intake airflow measurements, as discussed above. Figure 5 The place is being discussed.

[0118] As described above, directing airflow from the exhaust system to the engine intake port by reversing the unfueled engine can include commanding the intake throttle valve to fully open (e.g., 262, 320). In examples where the engine system includes an electric booster bypass valve (e.g., 361), the electric booster bypass valve can be additionally commanded to open to direct airflow from the exhaust system to the engine intake port without reversing the engine in the unfueled state. For vehicles equipped with an EGR passage (e.g., 380), the EGR valve (e.g., 352) can be commanded or kept closed when directing airflow from the exhaust system to the engine intake port includes reversing the unfueled engine. Furthermore, in this case, the exhaust valve (e.g., 391) can be commanded to open to deliver airflow around the turbine (e.g., 316). However, in other examples, without departing from the scope of this disclosure, the exhaust valve can be commanded to open without reversing the unfueled engine. In other examples, the exhaust valve may not be included in the vehicle system (see, for example...). Figure 2 ).

[0119] In another example, instead of reversing the rotation of an unfueled engine to direct airflow from the exhaust system to the engine intake, an electric booster (e.g., 355) can be used to draw airflow from the exhaust system into the engine intake. To draw airflow from the exhaust system into the engine intake, the electric booster can operate in reverse, similar to engine reversal (e.g., via the use of an H-bridge). In this case, the electric booster bypass valve (e.g., 361) can be commanded or maintained closed, the throttle valve (e.g., 320) can be actuated fully open, engine cylinder seals can be actuated, the EGR valve can be actuated open, and the wastegate valve can be actuated open. Sealing the engine cylinder can include actuating the intake and exhaust valves to close, for example, by sending a signal via a controller to the VDE actuators (e.g., 376, 377) to actuate the intake and exhaust valves of the engine cylinders to a closed configuration. In this way, the electric booster can draw air from the exhaust system into the engine intake to bypass the engine and turbine via the open EGR valve and the open wastegate valve.

[0120] In an example where the electric booster is not included in the vehicle system, it can be understood that delivering airflow from the exhaust system to the engine intake is done by reversing the rotation of the unfueled engine. However, as discussed above, in the case where the vehicle system includes the electric booster, reversing the electric booster to obtain the baseline airflow may be more energy-efficient, as the turbocharger and engine can be bypassed, as discussed. Therefore, the vehicle controller can determine whether to reverse the engine or, in the case of the electric booster in the vehicle system, utilize the electric booster to deliver airflow from the exhaust system to the engine intake based on battery charge, fuel level in the fuel tank, learned driving procedures, etc.

[0121] It is understandable that if the baseline intake airflow measurement value of method 500 is obtained by reversing the rotation of an unfueled engine, then delivering airflow from the exhaust system at 630 may include reversing the rotation of the unfueled engine. In this case, if the baseline measurement value is obtained with the exhaust valve open, then at 630, the exhaust valve can be commanded to open to deliver airflow from the exhaust system to the engine intake port. Similarly, if the baseline measurement value is obtained using an electric booster, then at 630, the electric booster can be similarly used to deliver airflow from the exhaust system to the engine intake port at 630. In such a case, using an electric booster to obtain the baseline measurement value may also include commanding the throttle valve, exhaust valve, and EGR valve to open fully (and sealing the engine cylinders), and then at 630, this action can be additionally performed to deliver airflow from the exhaust system to the engine intake port.

[0122] In other words, it can be understood that at steps 520 of method 500 and 630 of method 600, the exact same method can be used to deliver airflow from the exhaust system to the engine intake. More specifically, it can be understood that if the same method is used to obtain baseline and test measurements, then the diagnosis of GPF soot load levels based on baseline measurements (method 500) and test measurements (method 600) can be robust; however, if a different method is used to obtain baseline measurements compared to obtaining test measurements, then it may be prone to errors.

[0123] Furthermore, it is understood that if an electric booster is used to obtain baseline and test measurements, the rotational speed at which the electric booster is reversed to obtain the baseline measurements can be the same as the rotational speed at which the electric booster is reversed to obtain the test measurements. Similarly, if an unfueled engine is used to obtain baseline and test measurements by reversing its rotation, the rotational speed at which the engine is reversed to obtain the baseline measurements can be the same as the rotational speed at which the engine is reversed to obtain the test measurements.

[0124] After initiating airflow from the exhaust system to the engine intake at 630, method 600 may proceed to 635. At 635, method 600 may include acquiring / determining MAF sensor readings for a predetermined duration. It is understood that the predetermined duration may include the same predetermined duration described in step 525 of method 500. The MAF readings may be transmitted to a controller, and the MAF readings may be acquired periodically, as discussed above.

[0125] In response to the elapsed time, although not explicitly shown, it is understood that the controller can process the MAF data to obtain an average MAF determination during the process of delivering airflow from the exhaust system to the engine intake. The averaged or otherwise processed MAF data can be stored in the controller.

[0126] Proceeding to 640, method 600 may include indicating / determining via the controller that the difference between the baseline intake airflow data (obtained via method 500, and which may age based on engine operating time, expected / inferred / estimated dust intake, etc.) is greater than a threshold difference (obtained via method 600) in the test intake airflow data. The threshold difference may include, for example, a predetermined threshold and may be stored at the controller. It is understood that the closer the baseline intake airflow data is to the test intake airflow data, the less restricted the GPF is. Alternatively, the greater the difference between the baseline intake airflow data and the test intake airflow data, the more restricted the GPF is (e.g., more overloaded or more blocked).

[0127] Therefore, at 640, the controller can determine whether the baseline data is greater than a threshold difference from the test intake airflow data. If the difference is greater than the threshold difference at 640, then method 600 can proceed to 645. At 645, method 600 can include stopping the delivery of airflow from the exhaust system to the engine intake. For example, as discussed above, if delivering the airflow involves reversing the unfueled engine, then the engine can be stopped from reversing. Alternatively, in the case of delivering airflow from the exhaust system to the engine intake using an electric booster, the electric booster can be stopped from reversing. Furthermore, any valves actuated to open / close for delivery can return to their initial state. For example, if the engine is reversed to deliver airflow from the exhaust system to the engine intake, then the electric booster bypass valve can be commanded to close and the throttle valve can be returned to its position before delivery. Alternatively, if the airflow is delivered from the exhaust system to the engine intake using an electric booster, then the engine cylinders can be opened, the wastegate and EGR valve can be commanded to close, and the throttle valve can be returned to its position before delivery.

[0128] Proceeding to step 650, method 600 may include planning a GPF cleaning procedure and may include performing a GPF cleaning delivery in response to a condition being met. In one example, this condition may be met only after a controller indicates whether the difference between baseline airflows is greater than a threshold difference from a test airflow. For example, the cleaning procedure may include starting the engine to burn air and fuel, and may also include controlling refueling and / or sparking to lean engine operation. Lean engine operation can direct oxygen and hot exhaust air to the GPF for regeneration. In another example, cleaning may include delivering oxygen to the exhaust system via a compressor (e.g., an electric booster or turbocharger). In yet another example, regeneration may be performed during a deceleration fuel cut-off (DFSO) condition, where fuel is cut off from the engine, and thus oxygen becomes available in the exhaust.

[0129] In some examples, the regeneration process may include a predetermined duration, thereby enabling lean engine operation. In another example, the amount of time for the regeneration process may vary with the GPF limitation level. For example, the greater the difference between the baseline gas flow rate and the test gas flow rate, the longer the GPF can be regenerated.

[0130] In other examples, GPF cleaning can be scheduled at the next possible circumstance when the conditions for doing so are met. Since the indication is that the GPF is restricted and therefore requires cleaning, it is understood that the GPF cleaning procedure can be scheduled as early as possible after it has been determined that the GPF is restricted and cleaning is recommended.

[0131] In response to the cleaning procedure performed at 650, method 600 can proceed to 655. At 655, method 600 may include verifying that the GPF has been effectively cleaned. Although not explicitly shown, it is understood that verifying that the GPF has been effectively cleaned may include repeating steps 630 to 640 of method 600. If the GPF has been effectively cleaned, the difference between the baseline airflow and the difference between the test airflow can be substantially similar, for example, within 5% of each other. If, for some reason, it is indicated that the GPF has not been effectively cleaned, then the cleaning procedure can be rescheduled and performed in response to the conditions for doing so, and then it can be verified again that the GPF has been effectively cleaned. Such actions may be repeated any number of times until it is indicated that the GPF has been effectively cleaned.

[0132] In response to indication / determination that the GPF has been effectively cleaned, method 600 may proceed to 660. At 660, method 600 may include updating the vehicle condition to reflect the recently cleaned GPF. For example, updating the vehicle condition at 660 may include planning a new baseline intake flow program as soon as possible after the GPF cleaning procedure (e.g., method 500). In other words, after a GPF cleaning procedure has been performed, a baseline intake flow program can be planned once the conditions for doing so are met. Method 600 may then terminate.

[0133] Returning to 640, in response to the difference between the baseline intake airflow data (method 500) being less than a threshold difference from the test intake airflow data (method 600), method 600 may proceed to 665. At 665, method 600 may include any unplanned GPF cleaning procedures. Proceeding to 670, method 600 may include stopping the delivery of airflow from the exhaust system to the engine intake, as discussed above with respect to step 645 of method 600. Proceeding to 675, method 600 may include updating the vehicle condition to reflect information indicating that the GPF filter is not limited to the recommended filter cleaning point. For example, updating the vehicle condition may include planning another test diagnostic to determine the GPF limit level based on the degree of difference between the indications of the baseline intake airflow data and the test intake airflow data. For example, the less the GPF is loaded, the later the test diagnostic can be planned. Or, the more the GPF is loaded, the earlier the test diagnostic can be planned. Method 600 may then end.

[0134] about Figures 5 to 6The discussed method can thus achieve a method comprising regenerating a particulate filter located in the exhaust system of a vehicle's engine in response to a difference of at least a threshold amount between a first airflow in the engine's intake and a second airflow in the engine's intake, the airflow comprising airflow delivered from the exhaust system through the engine to the engine's intake. In this method, the first airflow may comprise a baseline intake airflow obtained under conditions where the particulate filter is known to be under load less than a threshold load (in other words, under conditions where the particulate filter is known to be substantially clean). For example, the first airflow may vary with the load condition of the intake filter. The baseline airflow in this method may age over time based on a model of the air introduced into the engine and / or the dust or other particulate matter captured by the intake filter.

[0135] In this method, the second airflow may include a test intake airflow and may be obtained under conditions where the differential pressure sensor coupled to the particulate filter is known to be degraded or not operating as expected or anticipated. Furthermore, in one example, the first and second airflows may be obtained / determined by reversing the rotation of an unfueled engine. In another example, the first and second airflows may be obtained / determined by reversing the rotation of an electric booster positioned in the engine intake. As an example, reversing the rotation of the electric booster may also include delivering the first and second airflows around the engine and a turbine positioned in the exhaust system.

[0136] This method may also include commanding the throttle valve, positioned in the engine intake, to be fully opened before the first and second airflows are obtained. In this method, the particulate filter may include either a gasoline particulate filter or a diesel particulate filter. Furthermore, this method may also include obtaining the first and second airflows when the vehicle is not in use and / or is being operated autonomously.

[0137] Figures 5 to 6 The method can also implement another method, which includes delivering a first airflow from the engine's exhaust system to the engine's intake port to obtain a baseline intake airflow under conditions where the particulate filter located in the exhaust system is loaded below a threshold load. This method can also include delivering a second airflow from the engine's exhaust system to the engine's intake port to obtain a test intake airflow under conditions independent of the particulate filter's load condition. This method can also include a particulate filter regeneration process in response to a difference of at least a threshold amount between the baseline intake airflow and the test intake airflow.

[0138] In this method, delivering the first airflow and delivering the second airflow may further include reversing the rotation of the engine without fuel. In another example of this method, delivering the first airflow and delivering the second airflow may further include reversing the operation of an electric booster located in the engine's intake port, wherein reversing the electric booster may further include delivering the first airflow and the second airflow around the engine and around a turbine located in the exhaust system. Delivering the first airflow and the second airflow around the engine and around the turbine may further include commanding the engine cylinders to be sealed, commanding the opening of an exhaust recirculation valve located in an exhaust recirculation passage, and commanding the opening of an exhaust valve located in an exhaust valve passage located in the exhaust system and configured to bypass the turbine.

[0139] In this method, the method may further include updating the baseline intake airflow after obtaining the baseline intake airflow and before obtaining the test intake airflow, wherein updating the baseline intake airflow may include modeling the baseline intake airflow that varies over time with the amount of air and other particulate matter drawn into the engine via the intake filter.

[0140] Furthermore, in this method, obtaining the baseline intake airflow and obtaining the test intake airflow may include monitoring a first airflow and a second airflow via a mass airflow sensor positioned in the engine's intake, wherein delivering the first and second airflows may further include commanding the throttle valve positioned in the engine's intake to fully open. Now turn to Figure 7 Example timeline 700 is shown, which illustrates the timeline based on... Figure 5The method shown here obtains baseline intake airflow measurements. More specifically, timeline 700 shows baseline intake airflow measurements obtained by reversing the rotation of an unfueled engine. Timeline 700 includes a curve 705 indicating whether the conditions for obtaining baseline data are met over time and a curve 710 indicating the state of the engine. The engine may rotate in the forward direction (e.g., the same direction as when the engine burns air and fuel), in the reverse direction, or may be stopped (e.g., not rotating). Timeline 700 also includes a curve 715 indicating the state of fuel injection supplied to the engine over time. Fuel injection may be on or off. Timeline 700 also includes a curve 720 indicating the position of the intake throttle valve over time. The throttle valve may be open (e.g., fully open), closed (e.g., fully closed), or somewhere in between. Timeline 700 also includes a curve 725 indicating engine speed over time. Engine speed may be 0 (e.g., not rotating), or may increase (+) compared to not rotating. Timeline 700 also includes a curve 730 indicating data obtained over time via a MAF sensor located in the engine intake. For example, the MAF sensor may indicate no flow or an airflow greater than (+) no flow. Timeline 700 also includes a curve 735 indicating whether the GPF differential pressure sensor has deteriorated over time. Timeline 700 also includes a curve 740 indicating the controller's status over time. The controller may be in sleep or wake-up mode.

[0141] At time t0, the conditions for obtaining baseline data are not indicated. In this example timeline, it can be understood that the controller plans diagnostics to obtain baseline intake airflow measurements, such that the controller is planned to wake up at a specific time frame after the controller has entered sleep mode. While the controller is still in sleep mode (curve 740), the conditions for obtaining baseline intake airflow data are not yet indicated (curve 705). The engine is stopped (curve 710), fuel injection is shut off (curve 715), and the throttle is in the position it was in during the last ignition shut-off event (curve 720). When the engine stops, the engine speed is 0 RPM (curve 725). Furthermore, with the engine off, no flow is indicated via the MAF sensor (curve 730). While it can be understood that the MAF sensor may not monitor airflow in the intake when the controller is in sleep mode, for illustrative purposes, the absence of flow in the engine intake when the engine is off is shown. Furthermore, GPF differential pressure sensor degradation is not indicated (curve 735).

[0142] At time t1, the time the controller has been in sleep mode has elapsed, and the controller is thus awakened (curve 740), indicating that the conditions for obtaining baseline intake airflow are met. Therefore, at time t2, the throttle is commanded to fully open (curve 720), and the engine is reverse-rotated (curve 710) without fuel (curve 715). The engine is controlled to reverse-rotate at a predetermined engine speed (e.g., predetermined engine RPM) (curve 725) without fuel between times t2 and t3. When the engine is reverse-rotated without fuel, airflow is delivered from the exhaust system to the engine intake via the engine. Although not explicitly shown, in some examples, the wastegate can be commanded / actuated to open in order to deliver air around the turbine. However, in other examples, the wastegate can be kept closed.

[0143] When airflow is delivered from the exhaust system to the engine intake, the MAF (Modular Airflow) is measured via a MAF sensor positioned in the engine intake (curve 730). The MAF can be measured over a predetermined duration, as discussed above. At time t3, after the predetermined duration, the MAF data is averaged to obtain the average MAF corresponding to the baseline intake airflow. The average MAF data or the baseline intake airflow is represented by the dashed line 731. The baseline intake airflow can be stored at the controller, as discussed above.

[0144] If baseline intake airflow is obtained at time t3, the engine can be stopped (curve 710), and the throttle valve (curve 720) can be returned to its position before being commanded to be fully open. If the engine is commanded to stop, between times t3 and t4, the engine speed returns to 0 RPM (curve 725), and the MAF in the intake returns to zero flow (curve 730).

[0145] At time t4, having obtained the baseline intake airflow measurement, the condition for obtaining baseline data is no longer indicated (curve 705), and the controller is thus returned to sleep mode (curve 740). Between times t4 and t5, the controller remains in sleep mode, and the engine remains off.

[0146] Turn now Figure 8Another example timeline 800 is shown, illustrating baseline intake airflow measurements obtained via an electric booster positioned in the engine intake port, upstream of the intake throttle valve. Timeline 800 includes curve 805 indicating whether the conditions for obtaining baseline data are met over time, and curve 810 indicating engine status. The engine may be stopped, rotating in reverse, or rotating in the forward direction. Timeline 800 also includes curve 815 indicating the state of fuel injection into the engine over time. Fuel injection may be turned on or off over time. Timeline 800 also includes curve 820 indicating the position of the intake throttle valve over time. Timeline 800 also includes curve 825 indicating engine speed over time. Engine speed may be 0 RPM or greater than 0 RPM (+). Timeline 800 also includes curve 830 indicating MAF (Mass Airflow) in the engine intake port over time. There may be no flow in the intake port, or there may be a flow increase (+) beyond no flow. Timeline 800 also includes curve 835 indicating whether the GPF differential pressure sensor has deteriorated over time. Timeline 800 also includes curve 840 indicating whether the controller is dormant or awake over time. Timeline 800 also includes curve 845 indicating whether the exhaust valve is open or closed over time and curve 850 indicating whether the EGR valve is open or closed over time. Timeline 800 also includes curve 855 indicating the state (open or closed) of the electric booster over time. In this example timeline, it can be understood that when the electric booster is on, the electric booster operates in reverse. Timeline 800 also includes curve 860 indicating whether the engine cylinder is sealed or open over time. It can be understood that "open" in this context refers to an engine cylinder that has not been actively sealed (e.g., via a VDE actuator), while "sealed" in this context refers to an engine cylinder whose intake and exhaust valves have been commanded or actuated to be closed (e.g., via a VDE actuator).

[0147] At time t0, the conditions for obtaining baseline data have not yet been indicated. In this example timeline, it can be understood that the controller plans diagnostics to obtain baseline intake airflow measurements, such that the controller is planned to wake up at a specific time frame after the controller has entered sleep mode. While the controller is still in sleep mode (curve 840), the conditions for obtaining baseline intake airflow data have not yet been indicated (curve 805). The engine stops at time t0 (curve 810), and therefore fuel injection to the engine is shut off (curve 815), and the engine speed is 0 RPM (curve 825). The throttle (curve 820) occupies the position where the throttle was when the engine was last shut off. The electric booster is off (curve 855), and therefore, with the engine off and the electric booster off, no flow is indicated via the MAF sensor (curve 830). It can be understood that the controller is in sleep mode at time t0 (curve 840), and therefore any flow in the intake will not be transmitted to the controller anyway; however, the MAF flow (curve 830) is indicated for reference. Furthermore, the exhaust valve (curve 845) is closed, the EGR valve (curve 850) is closed, and the engine cylinder seals are not commanded (curve 860). Finally, at time t0, there is no indication of GPF differential pressure sensor degradation (curve 835).

[0148] At time t1, the controller is awakened from hibernation mode (curve 840), and thus indicates that the conditions for obtaining baseline data have been met (curve 805). Therefore, at time t2, the throttle is commanded to fully open (curve 820), the exhaust valve is commanded to fully open (curve 845), the EGR valve is commanded to fully open (curve 850), the engine cylinders are commanded to seal (curve 860), and the electric booster is started in reverse. Furthermore, although not explicitly shown, it can be understood that the electric booster bypass valve (e.g., 361) is commanded or kept closed.

[0149] When the electric booster is reverse-activated at time t2, the airflow from the exhaust system to the engine intake is monitored via the MAF sensor between times t2 and t3. As discussed above, the MAF can be measured over a predetermined duration, and at time t3, this predetermined duration has elapsed. The MAF data is averaged to obtain the average MAF corresponding to the baseline intake airflow. The average MAF data, or baseline intake airflow, is represented by the dashed line 831. As discussed above, the baseline intake airflow can be stored at the controller.

[0150] With baseline intake airflow obtained at time t3, the electric booster is commanded to close, the exhaust valve is commanded to close, the EGR valve is commanded to close, the engine cylinders are commanded to open, and the throttle valve is returned to its position before the baseline data was obtained. With the electric booster commanded to close, and therefore without airflow being delivered from the exhaust system to the engine intake, the airflow in the engine intake recorded by the MAF sensor between times t3 and t4 returns to zero flow.

[0151] At time t4, having obtained the baseline intake airflow measurement, the condition for obtaining baseline data is no longer indicated (curve 805), and the controller is thus returned to sleep mode (curve 840). Between times t4 and t5, the controller remains in sleep mode, and the engine and electric booster remain off.

[0152] Turn now Figure 9 Example timeline 900 is shown, which illustrates the above regarding... Figure 6 The discussion focuses on obtaining test intake airflow measurements. Specifically, timeline 900 shows test intake airflow measurements obtained by reversing the rotation of an unfueled engine. Timeline 900 includes curve 905 indicating whether the conditions for obtaining the test intake airflow measurements are met (in order to determine whether the GPF is limited to the recommended cleanliness level). Timeline 900 also includes curve 910 indicating the state of the engine over time. The engine may be off, reversed, or rotating in the forward direction. Timeline 900 also includes curve 915 indicating the state of fuel injection into the engine over time. Timeline 900 also includes curve 920 indicating the position of the intake throttle valve over time. The throttle valve may be fully open, fully closed, or somewhere in between. Timeline 900 also includes curve 925 indicating engine speed over time. The engine speed may be 0 RPM or may increase (+) relative to 0 RPM. Timeline 900 also includes curve 930 indicating the MAF (Magnetic Airflow Factor) monitored by the MAF sensor in the engine intake over time. MAF can be zero flow or can increase relative to zero flow (+). Timeline 900 also includes curve 935 indicating whether the GPF differential pressure sensor is deteriorating over time. Timeline 900 also includes curve 940 indicating the status of the vehicle controller over time. The controller may be in sleep or wake-up mode. Timeline 900 also includes curve 945 indicating whether GPF regeneration or cleaning is scheduled over time.

[0153] At time t0, the conditions for determining the GPF limit level have not yet been indicated (curve 905). In this example timeline, it can be understood that at time t0, the GPF differential pressure sensor deteriorates (curve 935), and therefore a diagnostic test to determine the GPF limit is planned at a predetermined time point after the ignition shutdown event. In other words, the controller is planned to be woken up at a predetermined time after the ignition shutdown event for diagnostic testing. Therefore, at time t0, the controller goes into sleep mode (curve 940). At time t0, the engine shuts off (curve 910), and fuel injection to the engine is also shut off (curve 915). When the engine stops, the engine speed is 0 RPM (curve 925). Furthermore, with the engine off, there is no flow in the engine intake (curve 930). When the controller is in sleep mode, any flow in the engine intake may not be actively monitored via the MAF sensor; however, the indication of no flow is shown for reference. Furthermore, at time t0, the throttle body occupies its position in the last shut-off ignition event (curve 920), and there is currently no plan for GPF regeneration (curve 945).

[0154] At time t1, the controller is awakened from sleep mode for testing (curve 940). This indicates that the conditions for determining the GPF limit are met (curve 905). With the conditions for performing diagnostic tests to determine the GPF limit level met, at time t2, the throttle is commanded to fully open (curve 920), and the engine is started to reverse-engineer at a predetermined engine speed (curve 925) without fuel (curve 910). It is understood that, as discussed, the predetermined engine speed may include the same speed as the engine rotation to obtain baseline data.

[0155] With the engine rotating in reverse without fuel, the MAF (Motor Air Flow Rate) in the engine intake is monitored via an engine MAF sensor between times t2 and t3 (curve 930). It is understood that the MAF is monitored for a predetermined duration, which may include the same duration as when monitoring the MAF to obtain baseline data by reversing the engine rotation. At time t3, after the predetermined duration, the MAF is averaged to obtain the average MAF over the duration of monitoring the MAF between times t2 and t3. The average MAF corresponding to the test diagnostics is represented by the dashed line 931.

[0156] At time t3, the test MAF data (line 931) or test inlet airflow is compared by the controller with the baseline MAF data (line 731) or baseline inlet airflow. It can be understood that if the difference between the baseline inlet airflow (line 731) and the test inlet airflow (curve 931) is greater than a predetermined threshold difference, the controller will therefore schedule GPF regeneration (curve 945). In other words, by comparing the test inlet airflow with the baseline inlet airflow, the controller indicates that the GPF is being limited to the level where a cleaning or regeneration process is desired.

[0157] When the test intake airflow is compared with the baseline intake airflow at time t3, the engine is ordered to shut off (curve 910), and the throttle valve (curve 920) is returned to its position before the test intake airflow measurement was obtained.

[0158] When the engine is deactivated at time t3, the engine speed decreases to 0 RPM between times t3 and t4, and therefore the MAF decreases to zero flow between times t3 and t4. At time t4, the conditions for performing test diagnostics, or in other words, determining the GPF limit level, are no longer indicated (curve 905), and therefore, the controller enters sleep mode (curve 940). Between times t4 and t5, the controller remains in sleep mode with the engine off, and in the event of planned GPF regeneration, a GPF regeneration process will be initiated in response to the conditions for doing so.

[0159] Although not explicitly shown, it is understood that, in the case of reversing the engine to obtain baseline and test intake airflow measurements, and in the case of an engine system including an electric booster bypass valve, the electric booster bypass valve may be commanded to open while the throttle is open, so as to reverse the engine to obtain such measurements.

[0160] Turn now Figure 10 Another example timeline 1000 is shown, which illustrates the above regarding... Figure 6The discussion focuses on obtaining test intake airflow measurements. Specifically, timeline 1000 shows the acquisition of test intake airflow measurements via the use of an electric booster positioned in the engine intake port, upstream of the intake throttle valve. Timeline 1000 includes a curve 1005 indicating whether the conditions for obtaining the test intake airflow measurement, or in other words, determining the GPF limit level, are met over time. Timeline 1000 also includes a curve 1010 indicating the engine state over time. The engine may be stopped, or it may be rotating in reverse, or it may be rotating in the forward direction. Timeline 1000 also includes a curve 1015 indicating the state of fuel injection in the engine over time. Timeline 1000 also includes a curve 1020 indicating the position of the intake throttle valve over time. The throttle valve may be open (e.g., fully open), closed (e.g., fully closed), or somewhere in between. Timeline 1000 also includes a curve 1025 indicating the engine speed over time. The engine speed may be 0 RPM, or it may increase (+) relative to 0 RPM. Timeline 1000 also includes a curve 1030 indicating the MAF (Magnetic Fluid Pressure) monitored by a MAF sensor located in the engine intake port over time. This can be no flow or an increase (+) in flow relative to no flow. Timeline 1000 also includes a curve 1035 indicating whether the GPF differential pressure sensor is deteriorating over time. Timeline 1000 also includes a curve 1040 indicating whether the vehicle controller is dormant or awake over time. Timeline 1000 also includes a curve 1045 indicating the state of the exhaust valve over time. The exhaust valve can be open (e.g., fully open) or closed (e.g., fully closed). Timeline 1000 also includes a curve 1050 indicating the state of the EGR valve over time. The EGR valve can open (e.g., fully open) or close (e.g., fully closed) over time. Timeline 1000 also includes a curve 1055 indicating the state (on or off) of the electric booster over time. In this example timeline, when the electric booster is on, it can be understood that the electric booster is rotating in reverse. Timeline 1000 also includes curve 1060 indicating whether GPF regeneration / cleaning is planned over time.

[0161] At time t0, the conditions for determining the GPF limit level, or in other words, obtaining the test intake airflow measurement, have not yet been indicated (curve 1005). More specifically, in this example timeline, it can be understood that the controller is planned to be woken up at a predetermined time for test diagnostics, and when the controller is in sleep mode (curve 1040), the conditions for performing test diagnostics have not yet been indicated. However, when test diagnostics are planned, the GPF differential pressure sensor is indicated to be degraded (curve 1035). The engine is shut off (curve 1010), and therefore fuel injection to the engine is shut off (curve 1015), and the engine speed is 0 RPM (curve 1025). The throttle is in its position as it was in the last shut-off ignition event (curve 1020), and the electric booster is off (curve 1055). With the engine off and the electric booster off, there is no flow in the engine intake (no MAF) (curve 1030). When the controller is off at time t0, it can be understood that the MAF may not be transmitted to the controller via the MAF sensor; however, the MAF is shown for reference. Furthermore, at time t0, the exhaust valve is closed (curve 1045), the EGR valve is closed (curve 1050), and GPF regeneration is not yet planned (curve 1060).

[0162] At time t1, the controller transitions to a wake-up state to perform diagnostic tests (curve 1040). Therefore, at time t1, the condition for performing diagnostic tests to determine the GPF limit level or GPF load condition is indicated (curve 1005). If the condition for performing diagnostic tests is met at time t1, at time t2, the throttle is commanded to fully open (curve 1020), the exhaust valve is commanded to fully open (curve 1045), the EGR valve is commanded to fully open (curve 1050), and the electric booster is commanded to open in reverse. Due to the... Figure 10 Due to space constraints, the state of the engine cylinders is not indicated, but it can be understood that at time t2, the engine cylinders are commanded to seal. As discussed above, commanding the engine cylinders to seal can be understood to include the controller sending a signal to the VDE actuator, thereby actuating the closed intake and exhaust valves coupled to the engine cylinders. Furthermore, although not explicitly shown, at time t2, the electric booster bypass valve (e.g., 361) is commanded or remains closed.

[0163] Between times t2 and t3, with the electric booster operating in reverse, airflow is delivered from the exhaust system to the engine intake, and this airflow in the engine intake is monitored via a MAF sensor (curve 1030). The MAF is monitored for a predetermined duration, which includes the same duration as the time required to obtain the baseline intake airflow measurement via rotation, or in other words, the duration of the reverse-operation of the electric booster. At time t3, after the predetermined duration, the MAF monitored between times t2 and t3 is averaged to obtain an average MAF for test diagnostics, as indicated by line 1031. Furthermore, at time t3, the average MAF corresponding to the test diagnostics or test intake airflow is compared with the average MAF corresponding to the baseline diagnostics or baseline intake airflow (indicated by line 831). In this example timeline, it can be understood that the difference between the baseline intake airflow (line 831) and the test intake airflow (curve 1031) is greater than a predetermined threshold difference, and therefore GPF regeneration is planned (curve 1060).

[0164] At time t3, having elapsed for a predetermined duration, the throttle body returns to its position before the test and diagnostics were performed (curve 1020), the exhaust valve is commanded to close (curve 1045), the EGR valve is commanded to close (curve 1050), and the electric booster is commanded to close (curve 1055). Although not explicitly shown due to space constraints, it can be understood that the engine cylinders are commanded to open at time t3.

[0165] With the electric booster off, the MAF decreases to zero between times t3 and t4 (curve 1030). At time t4, the controller returns to sleep mode (curve 1040) and no longer indicates that the conditions for performing diagnostic tests to determine the GPF limit level have been met (curve 1005). Between times t4 and t5, the controller remains in sleep mode and may perform GPF cleaning in response to the conditions for doing so.

[0166] As discussed above, a planned GPF cleaning procedure, as discussed with respect to example timelines 900 and 1000, may include starting the engine to combust air and fuel, and may also include controlled refueling and / or sparking to lean engine operation. Lean engine operation directs oxygen and hot exhaust air to the GPF for regeneration. Therefore, once planned, such a process can be performed in response to the conditions for doing so. Furthermore, once the cleaning process has been performed, verification can be conducted regarding whether the GPF has been effectively cleaned. More specifically, if the test diagnostics include reversing the engine to deliver airflow from the exhaust system to the engine intake, then according to method 600, the engine can be reversed again (in response to the conditions for doing so), and the MAF in the engine intake can be compared with a previously determined baseline MAF (established under the condition of reversing the engine). If the MAF recorded after the GPF regeneration process is substantially equivalent to the baseline MAF (e.g., within 5%), then the GPF cleaning process can be indicated to be effective. At this point, baseline intake airflow diagnostics can be planned to obtain a baseline intake airflow with a clean GPF. If the cleaning procedure does not effectively clean the GPF, the cleaning process can be repeated as many times as possible in order to effectively clean the GPF.

[0167] In another example, if the test diagnostics include reversing the electric booster to deliver airflow from the exhaust system to the engine intake, then according to method 600, the electric booster can be reversed again (in response to the conditions for doing so), and the MAF in the engine intake can be compared with the previously determined baseline MAF (established under the condition of reversing the electric booster). Similarly, if the MAF recorded after the GPF regeneration process is substantially equivalent to the baseline MAF (e.g., within 5%), then the GPF cleaning procedure can be indicated as effective. At this point, another baseline intake airflow diagnostic can be planned so that baseline intake airflow can be obtained with a clean GPF. Similar to what has been discussed above, if the cleaning procedure does not effectively clean the GPF, then the cleaning process can be repeated any number of times to effectively clean the GPF.

[0168] In this way, when the GPF differential pressure sensor indicates deterioration or otherwise malfunctions, the GPF limit can be effectively determined, and a planned cleaning procedure can be initiated when the GPF limit exceeds a predetermined level. Doing so improves engine operation and reduces engine degradation associated with exhaust system limitations (due to GPF load).

[0169] The technical effect is that the MAF in the engine intake can be used as a reading of the GPF limit when the GPF differential pressure sensor deteriorates or otherwise fails to operate as expected. More specifically, the technical effect is that the baseline MAF recorded under known GPF clean conditions (e.g., load less than a predetermined threshold load condition) can be compared with the test MAF recorded under known / inferred GPF differential pressure sensor deterioration conditions to infer the GPF limit level. Therefore, another technical effect is that such MAFs (baseline and test) can be obtained by reversing the engine rotation or by reversing the electric booster positioned in the engine intake. Yet another technical effect is that, under conditions where the electric booster is reversed, it may be desirable to bypass the engine and turbocharger by sealing the engine cylinders and commanding the EGR valve and exhaust valve to open. Yet another technical effect is that the baseline intake airflow measurement can vary depending on the load condition of the intake filter. Therefore, the technical effect is to age the baseline measurement via a model stored at the controller so that, during intake airflow test measurements, the baseline intake airflow measurement reflects the current state of the intake filter. This “aging” of baseline measurements can be based on the airflow introduced into the engine and estimates of the dust / debris that may therefore accumulate on the intake filter.

[0170] This article and references Figures 1 to 4B The system described herein and referenced Figures 5 to 6The described methods can implement one or more systems and methods. In one example, a method includes regenerating a particulate filter located in the exhaust system of a vehicle's engine in response to a first airflow in the engine's intake port differing from a second airflow in the engine's intake port by at least a threshold amount, the airflow comprising airflow delivered from the exhaust system through the engine to the engine's intake port. In a first example of the method, the method may further include wherein the first airflow comprises a baseline intake airflow obtained under conditions where the particulate filter is known to be under load less than a threshold load state. A second example of the method optionally includes the first example and further includes wherein the first airflow varies with the load state of the intake filter, and wherein the baseline airflow is aged over time according to a model of the air introduced into the engine and / or dust or other particulate matter captured by the intake filter. A third example of the method optionally includes any one or more of the first to second examples and further includes wherein the second airflow comprises a test intake airflow and is obtained under conditions where the differential pressure sensor coupled to the particulate filter is known to be degraded or not operating as expected or anticipated. A fourth example of the method optionally includes any one or more of the first to third examples, and further includes obtaining the first and second airflows via reversing the rotation of an unfueled engine. A fifth example of the method optionally includes any one or more of the first to fourth examples, and further includes obtaining the first and second airflows via reversing the rotation of an electric booster positioned in the engine intake. A sixth example of the method optionally includes any one or more of the first to fifth examples, and further includes reversing the rotation of the electric booster, which also includes delivering the first and second airflows around the engine and a turbine positioned in the exhaust system. A seventh example of the method optionally includes any one or more of the first to sixth examples, and further includes commanding the full opening of a throttle valve positioned in the engine intake before obtaining the first and second airflows. An eighth example of the method optionally includes any one or more of the first to eighth examples, and further includes wherein the particulate filter includes a gasoline particulate filter or a diesel particulate filter. A ninth example of the method optionally includes any one or more of the first to eighth examples, and further includes obtaining the first and second airflows when the vehicle is not occupied and / or is autonomously operated.

[0171] Another example of a method includes: delivering a first airflow from the engine's exhaust system to the engine's intake port to obtain a baseline intake airflow under conditions where a particulate filter located in the exhaust system is loaded below a threshold load; delivering a second airflow from the engine's exhaust system to the engine's intake port to obtain a test intake airflow under conditions independent of the particulate filter's load condition; and performing a particulate filter regeneration process in response to a difference of at least a threshold amount between the baseline intake airflow and the test intake airflow. In a first example of the method, the method further includes wherein delivering the first airflow and delivering the second airflow also includes reversing the rotation of the engine without fuel. A second example of the method optionally includes the first example and further includes wherein delivering the first airflow and delivering the second airflow also includes reversing the operation of an electric booster located in the engine's intake port, wherein reversing the operation of the electric booster also includes delivering the first airflow and the second airflow around the engine and around a turbine located in the exhaust system. A third example of the method optionally includes any one or more of the first to second examples, and further includes, wherein delivering the first and second airflows around the engine and around the turbine, includes commanding the engine cylinders to be sealed, commanding the opening of an exhaust recirculation valve in a positioned exhaust recirculation passage, and commanding the opening of an exhaust valve in a positioned exhaust valve passage located in the exhaust system and configured to bypass the turbine. A fourth example of the method optionally includes any one or more of the first to third examples, and further includes updating the baseline intake airflow after obtaining the baseline intake airflow and before obtaining the test intake airflow, wherein updating the baseline intake airflow includes modeling the baseline intake airflow that varies over time with the amount of air and other particulate matter drawn into the engine via the intake filter. A fifth example of the method optionally includes any one or more of the first to fourth examples, and further includes, wherein obtaining the baseline intake airflow and obtaining the test intake airflow includes monitoring the first and second airflows via a mass airflow sensor positioned in the engine's intake port; and wherein delivering the first and second airflows includes commanding the full opening of a throttle valve positioned in the engine's intake port.

[0172] A system for a hybrid vehicle includes: an engine including an intake port and an exhaust system; a particulate filter located in the exhaust system, the particulate filter including a differential pressure sensor configured to indicate the load state of the particulate filter; an electric motor capable of rotating an unfueled engine; a mass airflow sensor located in the engine intake port; a throttle valve located in the engine intake port; and a controller having computer-readable instructions stored in a non-transitory memory, the computer-readable instructions causing the controller to perform the following actions when executed. Operation: In response to an indication that the particulate filter's load condition is below a predetermined threshold load condition, a first airflow is delivered from the exhaust system to the engine's intake port and a baseline intake airflow is recorded via a mass airflow sensor; at a later time, in the event of a differential pressure sensor indicating deterioration and when the particulate filter's load condition is independent of the differential pressure sensor reading, a second airflow is delivered from the exhaust system to the engine's intake port and a test intake airflow is recorded via a mass airflow sensor, wherein delivering the first and second airflows includes commanding the throttle to fully open; and a particulate filter regeneration process is performed in response to the baseline intake airflow differing from the test intake airflow by at least a threshold amount. In a first example of the system, the system also includes additional instructions stored in the controller for delivering the first and second airflows via rotating an unfueled engine using a motor. A second example of the system optionally includes the first example and further includes: an electric booster located in the engine intake port, upstream of the throttle valve; an exhaust gas recirculation valve located in an exhaust gas recirculation passage connecting the exhaust system to the engine intake port; a wastegate located in a wastegate passage in the exhaust system configured to deliver fluid flow around a turbine located in the exhaust system; an electric booster bypass valve located in the engine intake port, upstream of the throttle valve; a variable displacement engine actuator for sealing engine cylinders; and wherein the controller stores additional instructions for delivering a first airflow and a second airflow via reverse operation of the electric booster, wherein the exhaust gas recirculation valve is commanded to open, the wastegate is commanded to open, the electric booster bypass valve is commanded to close, and the engine cylinders are sealed. A third example of the system optionally includes any one or more of the first to second examples, and further includes: one or more of a seat load sensor, a door sensing technology and / or an on-board camera; and wherein the controller stores additional instructions for delivering a first airflow and a second airflow in a condition indicating that the hybrid vehicle is not occupied, wherein the occupancy status is indicated via one or more of the seat load sensor, the door sensing technology and / or the on-board camera.

[0173] It should be noted that the example control and estimation programs included herein can be used with various engine and / or vehicle system configurations. The control methods and programs disclosed herein can be stored as executable instructions in non-transitory memory and can be executed by a control system including a controller in conjunction with various sensors, actuators, and other engine hardware. The specific programs described herein can represent one or more of any number of processing strategies (such as event-driven, interrupt-driven, multi-tasking, multi-threaded processing strategies, etc.). Therefore, the various actions, operations, or functions shown can be performed in the order shown, in parallel, or in some cases omitted. Similarly, the processing order is not necessarily required to achieve the features and advantages of the example embodiments described herein, but is provided for ease of illustration and description. One or more of the actions, operations, and / or functions shown may be repeatedly performed depending on the specific strategy used. Furthermore, the actions, operations, and / or functions can be graphically represented as code programmed into a non-transitory memory of a computer-readable storage medium in an engine control system, wherein the actions are performed by combining instructions in a system including various engine hardware components with an electronic controller.

[0174] It will be understood that the configurations and procedures disclosed herein are exemplary in nature, and these specific embodiments should not be considered limiting, as many variations are possible. For example, the above-described 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 various systems and configurations, as well as other features, functions, and / or properties disclosed herein.

[0175] The following claims specifically point to certain combinations and sub-combinations considered novel and non-obvious. These claims may relate to an “a” element or a “first” element or its equivalents. These claims should be understood to include combinations of 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 amendment to these claims or by filing new claims in this application or related applications. These claims, whether broader, narrower, equivalent, or different in scope from the original claims, are considered to be included within the subject matter of this disclosure.

[0176] According to the present invention, a method is provided comprising: regenerating a particulate filter located in the exhaust system of the engine of a vehicle in response to a first airflow in the engine intake differing from a second airflow in the engine intake by at least a threshold amount, the airflow comprising airflow delivered from the exhaust system through the engine to the engine intake.

[0177] According to one embodiment, the first airflow includes a baseline inlet airflow obtained under conditions where the particulate filter is known to be loaded below a threshold load state.

[0178] According to one embodiment, the first airflow varies with the load state of the intake filter, and the baseline airflow is aged over time according to a model of the air introduced into the engine and / or the dust or other particulate matter captured by the intake filter.

[0179] According to one embodiment, the second airflow includes a test inlet airflow and is obtained under conditions where the differential pressure sensor coupled to the particulate filter is known to be degraded or not operating as expected or anticipated.

[0180] According to one embodiment, the first airflow and the second airflow are obtained by reversing the rotation of the unfueled engine.

[0181] According to one embodiment, the first airflow and the second airflow are obtained by reversing the rotation of an electric booster located in the engine intake.

[0182] According to one embodiment, reversing the rotation of the electric booster further includes delivering the first airflow and the second airflow around the engine and a turbine positioned in the exhaust system.

[0183] According to one embodiment, the invention is further characterized in that the throttle valve positioned in the engine intake is commanded to be fully opened before the first airflow and the second airflow are obtained.

[0184] According to one embodiment, the particulate filter includes either a gasoline particulate filter or a diesel particulate filter.

[0185] According to one embodiment, the invention is further characterized in that the first airflow and the second airflow are obtained when the vehicle is not being used and / or is not being operated autonomously.

[0186] According to the present invention, a method is provided comprising: delivering a first airflow from an exhaust system of an engine to an intake port of the engine to obtain a baseline intake airflow under conditions where a particulate filter located in the exhaust system is loaded below a threshold load; delivering a second airflow from the exhaust system of the engine to an intake port of the engine to obtain a test intake airflow under conditions independent of the load state of the particulate filter; and performing a regeneration process of the particulate filter in response to a difference of at least a threshold amount between the baseline intake airflow and the test intake airflow.

[0187] According to one embodiment, delivering the first airflow and delivering the second airflow further includes causing the engine to rotate in reverse without fuel.

[0188] According to one embodiment, delivering the first airflow and delivering the second airflow further includes reversing an electric booster positioned in the air intake of the engine, wherein reversing the electric booster further includes delivering the first airflow and the second airflow around the engine and around a turbine positioned in the exhaust system.

[0189] According to one embodiment, delivering the first airflow and the second airflow around the engine and around the turbine further includes commanding the cylinders of the engine to be sealed, commanding the opening of an exhaust recirculation valve located in an exhaust recirculation passage, and commanding the opening of an exhaust valve located in an exhaust valve passage located in the exhaust system and configured to bypass the turbine.

[0190] According to one embodiment, the invention is further characterized in that the baseline intake airflow is updated after the baseline intake airflow is obtained and before the test intake airflow is obtained, wherein updating the baseline intake airflow includes modeling the baseline intake airflow, which varies over time with the amount of air and other particulate matter drawn into the engine via the intake filter.

[0191] According to one embodiment, obtaining the baseline intake airflow and obtaining the test intake airflow includes monitoring the first airflow and the second airflow via a mass airflow sensor positioned in the intake port of the engine; and wherein delivering the first airflow and the second airflow further includes commanding a throttle valve positioned in the intake port of the engine to be fully opened.

[0192] According to the present invention, a system for a hybrid vehicle is provided, comprising: an engine including an intake port and an exhaust system; a particulate filter located in the exhaust system, the particulate filter including a differential pressure sensor configured to indicate the load state of the particulate filter; an electric motor capable of rotating the engine when unfueled; a mass air flow sensor located in the intake port of the engine; a throttle valve located in the intake port of the engine; and a controller having computer-readable instructions stored in a non-transitory memory, the computer-readable instructions, when executed, causing the controller to perform the following operations. The process involves: responding to an indication that the load condition of the particulate filter is below a predetermined threshold load condition, delivering a first airflow from the exhaust system to the intake port of the engine and recording a baseline intake airflow via the mass airflow sensor; later, in a condition indicating deterioration of the differential pressure sensor and when the load condition of the particulate filter is independent of the differential pressure sensor reading, delivering a second airflow from the exhaust system to the intake port of the engine and recording a test intake airflow via the mass airflow sensor, wherein delivering the first and second airflows includes commanding the throttle to fully open; and performing a particulate filter regeneration process in response to a difference of at least a threshold amount between the baseline intake airflow and the test intake airflow.

[0193] According to one embodiment, the controller stores additional instructions for delivering the first airflow and the second airflow by rotating the unfueled engine via the motor.

[0194] According to one embodiment, the invention further features: an electric booster positioned in the intake port of the engine, upstream of the throttle valve; an exhaust gas recirculation valve positioned in an exhaust gas recirculation passage connecting the exhaust system to the intake port of the engine; a wastegate positioned in a wastegate passage in the exhaust system, the wastegate passage being configured to deliver fluid flow around a turbine positioned in the exhaust system; an electric booster bypass valve positioned in the intake port of the engine, upstream of the throttle valve; a variable displacement engine actuator for sealing the cylinders of the engine; and wherein the controller stores additional instructions for delivering the first airflow and the second airflow via reverse operation of the electric booster, wherein the exhaust gas recirculation valve is commanded to open, the wastegate is commanded to open, the electric booster bypass valve is commanded to close, and the cylinders of the engine are sealed.

[0195] According to one embodiment, the invention is further characterized by: one or more of a seat load sensor, a door sensing technology and / or an on-board camera; and wherein the controller stores additional instructions for operating to deliver the first airflow and the second airflow in a condition indicating that the hybrid vehicle is not occupied, wherein the occupancy status is indicated via one or more of the seat load sensor, the door sensing technology and / or the on-board camera.

Claims

1. A control method for a hybrid vehicle, comprising: A first airflow and a second airflow in the engine's air intake are recorded via a mass airflow sensor located in the engine's air intake. In response to a difference of at least a threshold amount between the first airflow and the second airflow in the engine's air intake, a particulate filter located in the exhaust system of the vehicle's engine is regenerated. The first and second airflows comprise airflow delivered from the exhaust system through the engine to the engine's air intake. The first airflow includes a baseline intake airflow obtained under conditions where the particulate filter is known to be under load less than a threshold load. The second airflow includes a test intake airflow obtained under conditions where a differential pressure sensor connected to the particulate filter is known to be degraded.

2. The method of claim 1, wherein the first airflow varies with the load state of the intake filter, and wherein the baseline intake airflow is aged over time according to a model of the air introduced into the engine and / or the dust or other particulate matter captured by the intake filter.

3. The method of claim 1, wherein the first airflow and the second airflow are obtained by reversing the rotation of the unfueled engine.

4. The method of claim 1, wherein the first airflow and the second airflow are obtained by reversing an electric booster positioned in the engine intake.

5. The method of claim 4, wherein rotating the electric booster in reverse further comprises delivering the first airflow and the second airflow around the engine and a turbine positioned in the exhaust system.

6. The method of claim 1, further comprising commanding the throttle valve positioned in the engine intake to be fully opened before the first airflow and the second airflow are obtained.

7. The method of claim 1, wherein the particulate filter comprises a gasoline particulate filter or a diesel particulate filter.

8. The method of claim 1, further comprising obtaining the first airflow and the second airflow when the vehicle is not in use and / or is not autonomously operated.

9. A system for a hybrid vehicle, comprising: An engine, the engine including an air intake and an exhaust system; A particulate filter located in the exhaust system, the particulate filter including a differential pressure sensor configured to indicate the load status of the particulate filter; An electric motor that enables the engine to rotate when it is not fueled; A mass air flow sensor, wherein the mass air flow sensor is positioned in the air intake of the engine; Throttle valve, the throttle valve being positioned in the air intake of the engine; as well as A controller having computer-readable instructions stored in a non-transitory memory, which, when executed, cause the controller to perform the following operations: In response to an indication that the load state of the particulate filter is below a predetermined threshold load state, a first airflow is delivered from the exhaust system to the air intake of the engine and a baseline intake airflow is recorded via the mass airflow sensor; At a later time, under conditions indicating degradation of the differential pressure sensor and when the load state of the particulate filter is independent of the differential pressure sensor reading, a second airflow is delivered from the exhaust system to the engine intake port and a test intake airflow is recorded via the mass airflow sensor, wherein delivering the first and second airflows includes commanding the throttle valve to fully open; and The particulate filter regeneration process is performed in response to a difference of at least a threshold amount between the baseline inlet airflow and the test inlet airflow.

10. The system of claim 9, wherein the controller stores additional instructions for delivering the first airflow and the second airflow by rotating the unfueled engine via the motor.

11. The system of claim 9, further comprising: An electric booster, the electric booster being positioned in the air intake of the engine, upstream of the throttle valve; An exhaust gas recirculation valve is positioned in an exhaust gas recirculation passage that connects the exhaust system to the intake port of the engine; An exhaust valve, wherein the exhaust valve is located in an exhaust valve passage in the exhaust system, the exhaust valve passage being configured to deliver fluid flow around a turbine located in the exhaust system; An electric booster bypass valve is located in the intake port of the engine, upstream of the throttle valve; A variable displacement engine actuator for sealing the cylinders of the engine; and The controller stores additional instructions for the following operations: delivering the first airflow and delivering the second airflow via reverse operation of the electric booster, wherein the exhaust gas recirculation valve is commanded to open, the exhaust valve is commanded to open, the electric booster bypass valve is commanded to close, and the cylinders of the engine are sealed.

12. The system of claim 9, further comprising: Seat load sensors and / or onboard cameras; and The controller stores additional instructions for the following operations: delivering the first airflow and the second airflow when the hybrid vehicle is not in use, wherein the occupancy status is indicated via the seat load sensor and / or the onboard camera.

13. The system of claim 9, wherein the particulate filter comprises a gasoline particulate filter or a diesel particulate filter.

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