Method and system for catalyst oxygen storage in monitored and unmonitored volumes for vehicle exhaust systems

Abstract

In various embodiments, methods and systems are provided that include one or more vehicle sensors and a vehicle processor. The one or more sensors are configured to obtain sensor data on the operation of one or more of the vehicle's catalytic converters. The processor is coupled to the one or more sensors and configured to perform at least the following: determining, using the sensor data in combination with a physics-based model, the oxygen saturation value of a catalyst in the one or more catalytic converters; determining whether the catalyst's oxygen saturation value exceeds a predetermined threshold; and implementing one or more oxygen purge strategies, via instructions provided by the processor, when the catalyst's oxygen saturation value exceeds the predetermined threshold.

Description

The technical field generally concerns vehicles and, in particular, methods and systems for controlling the storage of catalyst oxygen in exhaust systems for vehicles. Many vehicles today include exhaust systems with catalytic converters that treat the exhaust gas from the vehicle's engine. In various situations, it may be desirable to control the oxygen storage levels in the catalytic converters. DE 10 2018 251 720 A1 describes a method for controlling a modeled fill level of an exhaust gas component storage unit in a catalytic converter of an internal combustion engine, wherein the control of the modeled fill level is carried out using a linear model. The method determines the actual maximum storage capacity of the catalytic converter for the exhaust gas component during operation of the internal combustion engine, which is taken into account when controlling the modeled fill level. Furthermore, a control unit is described. DE 10 2005 061 875 A1 describes a method for controlling the oxygen concentration in the exhaust gas upstream of a catalytic converter of an internal combustion engine, wherein a control variable is generated based on signals from at least one exhaust gas sensor such that the oxygen storage capacity of the catalytic converter is alternately increased and decreased. The method increases and decreases the oxygen storage capacity by a predetermined amount of oxygen. Furthermore, a control unit that manages the execution of such a method is described. US Patent 2004 / 0045282A1 describes an exhaust gas control device and an exhaust gas purification method for an internal combustion engine equipped with a first catalyst section located in the exhaust stream of the engine and a second catalyst section located downstream of the first catalyst section in the exhaust stream. A value that changes at least by the amount of oxygen stored in the first catalyst section is recorded as a measured value. The air-fuel ratio of the internal combustion engine is controlled so that the measured value corresponds to a setpoint. A value that changes at least by the amount of oxygen stored in the second catalyst section is calculated as a measured value, based on at least one state of the exhaust gas flowing into the second catalyst section. The setpoint is adjusted according to the measured value. DE 10 2013 009 476 A1 describes a method for controlling a motor vehicle with an internal combustion engine and a catalytic converter, comprising the steps of: determining an oxygen storage value, which is a measure of oxygen stored in the catalytic converter; detecting an engine load; and performing a partial removal of oxygen from the catalytic converter with fuel enrichment when the oxygen storage value exceeds a trigger removal threshold and when the engine load is below a low-load threshold. It can be considered a task to specify methods and systems with which oxygen storage values ​​in catalytic converters can be better controlled. The problem is solved by a method according to claim 1 and by a system according to claim 7. Furthermore, a vehicle is described. A method according to the invention is described, comprising the following: obtaining sensor data relating to the operation of one or more catalytic converters of a vehicle, via one or more sensors of the vehicle; determining, via a processor of the vehicle, using the sensor data in combination with a physics-based model, an oxygen saturation value of a catalyst of the one or more catalytic converters; determining, via the processor, whether the oxygen storage value of the catalyst exceeds a predetermined threshold; and implementing one or more oxygen purge strategies, via instructions provided by the processor, when the oxygen saturation value of the catalyst exceeds the predetermined threshold.The oxygen saturation value is determined by the processor based on each of the following: temperature of the gas flow, flow velocity of the gas flow, mass flow rate of the gas flow, flow uniformity of the gas flow, an operating state of an engine of the vehicle and a voltage output from one or more sensors. In another embodiment, the one or more catalytic converters include a plurality of catalytic converters, and the oxygen saturation value is determined via the processor for each of the plurality of catalytic converters using the sensor data and the physics-based model, regardless of whether each of the plurality of catalytic converters includes oxygen sensors. In one embodiment, the method further includes selecting, via the processor, one of a selected oxygen purge strategy from a plurality of potential oxygen purge strategies based on the sensor data and the physics-based model; wherein the step of implementing one or more oxygen purge strategies includes implementing the selected oxygen purge strategy from the plurality of potential oxygen purge strategies according to instructions provided to and implemented by one or more actuators of the vehicle, based on the selected oxygen purge strategy from the plurality of potential oxygen purge strategies. In one embodiment, the processor also selects the chosen oxygen purge strategy from the multitude of potential strategies based on one or more of the following: gas flow temperature, gas flow velocity, gas flow mass flow rate, gas flow uniformity, an operating state of a vehicle engine, and a voltage output from one or more sensors. In one embodiment, the processor also selects the chosen oxygen purge strategy from the multitude of potential strategies based on each of the following: gas flow temperature, gas flow velocity, gas flow mass flow rate, gas flow uniformity, an operating state of a vehicle engine, and a voltage output from one or more sensors. In one embodiment, the selection of the chosen oxygen purge strategy from the multitude of potential strategies is also carried out by: (i) applying fuel; (ii) changing when the fuel is applied; (iii) applying a bias; (iv) manipulating a velocity of the gas flow; and (v) adjusting one or more locations on the one or more catalytic converters with which the gas flow will come into contact. In one embodiment, the acquisition of sensor data, the determination of the oxygen saturation value of the gas stream, the determination of whether the oxygen saturation value exceeds the predetermined threshold; and the implementation of one or more oxygen purge strategies are performed continuously during the operation of the vehicle's engine, regardless of whether a fuel cut-off event has occurred for the vehicle. In one embodiment, once the one or more oxygen purge strategies are determined, the one or more oxygen purge strategies are implemented via the instructions provided by the processor, regardless of the operating state of a vehicle's fuel control system. A system according to the invention is described, comprising one or more vehicle sensors and a vehicle processor. The one or more sensors are configured to obtain sensor data on the operation of one or more catalytic converters of the vehicle. The processor is coupled to the one or more sensors and configured to enable at least the following: determining, using the sensor data in combination with a physics-based model, an oxygen saturation value of a catalyst in the one or more catalytic converters; determining whether the oxygen saturation value of the catalyst exceeds a predetermined threshold; and implementing one or more oxygen purge strategies, via instructions provided by the processor, when the oxygen saturation value of the catalyst exceeds the predetermined threshold.The processor is further configured to enable at least the determination of the oxygen saturation value based on each of the following: temperature of the gas flow, flow velocity of the gas flow, mass flow rate of the gas flow, flow uniformity of the gas flow, an operating state of an engine of the vehicle and a voltage output from one or more sensors. In one embodiment, the one or more catalytic converters include a plurality of catalytic converters and the processor is configured to enable at least the determination of the oxygen saturation value for each of the plurality of catalytic converters using the sensor data and the physics-based model, regardless of whether each of the plurality of catalytic converters includes oxygen sensors. In one embodiment, the processor is further configured to enable at least the determination of the oxygen saturation value based on one or more of the following: temperature of the gas flow, flow velocity of the gas flow, mass flow rate of the gas flow, flow uniformity of the gas flow, an operating state of an engine of the vehicle and a voltage output from the one or more sensors. In one embodiment, the processor is further configured to enable at least the following: selecting one from a variety of potential oxygen purge strategies based on the sensor data and the physics-based model; and implementing the selected oxygen purge strategy from the variety of potential strategies according to instructions provided to and implemented by one or more actuators of the vehicle, based on the selected oxygen purge strategy from the variety of potential strategies. In one embodiment, the processor is further configured to enable at least the selection of the chosen oxygen purge strategy from the multitude of potential strategies based on each of the following: gas flow temperature, gas flow velocity, gas flow mass flow rate, gas flow uniformity, an operating state of a vehicle engine, and a voltage output from one or more sensors. In one embodiment, the processor is further configured to enable at least the selection of the chosen oxygen purge strategy from the multitude of potential strategies from the following: (i) applying fuel; (ii) changing when the fuel is applied; (iii) applying a bias; (iv) manipulating a gas flow velocity; and (v) adjusting one or more locations on the one or more catalytic converters with which the gas flow will come into contact. In one embodiment, the one or more sensors are also configured to receive the sensor data, and the processor is configured to enable at least the following: determining the oxygen saturation value of the gas stream; determining whether the oxygen saturation value exceeds the predetermined threshold; and implementing the one or more oxygen purge strategies continuously during the operation of a vehicle's engine, regardless of whether a fuel cut-off event has occurred for the vehicle. A vehicle is described that includes the following: a body; a drive system for moving the body; an exhaust system with a plurality of catalytic converters; a control system comprising one or more sensors and a processor; and one or more actuators. The one or more sensors are configured to obtain sensor data on the operation of the plurality of catalytic converters.The processor is coupled to and configured with one or more sensors to perform at least the following tasks: determining, using the sensor data in combination with a physics-based model, the oxygen saturation value of a catalyst in one or more catalytic converters, regardless of whether each of the multiple catalytic converters includes oxygen sensors; determining whether the catalyst's oxygen saturation value exceeds a predetermined threshold; selecting one from a multiple of potential oxygen purge strategies based on the sensor data and the physics-based model; and providing instructions to implement the selected one or more oxygen purge strategies when the oxygen saturation value exceeds the predetermined threshold.The one or more actuators are coupled to the processor and configured to implement the instructions for the selected one or more oxygen purge strategies when the oxygen saturation level exceeds the predetermined threshold. The processor is further configured to perform at least the determination of the oxygen saturation value based on each of the following: temperature, flow velocity, or mass flow rate of the gas stream; and the selection of the chosen strategy from the multitude of potential oxygen purge strategies from the following: (i) applying fuel; (ii) changing when the fuel is applied; (iii) applying a bias; (iv) manipulating the flow velocity of the gas stream; and (v) adjusting one or more locations on the multitude of catalytic converters with which the gas stream will come into contact. The present description is further described below in conjunction with the following drawings, where identical reference numerals denote identical elements, and where: Fig. 1 is a functional block diagram of a vehicle comprising an engine, an exhaust system, and a control system configured to control the exhaust system, including the storage of oxygen in catalytic converters of the exhaust system; Fig. 2 is a functional diagram of the exhaust system of the vehicle from Fig. 1; and Fig. 3 is a flowchart of a process for controlling the storage of oxygen in an exhaust system of a vehicle, and which can be implemented in conjunction with the vehicle from Fig. 1 and including its control system from Fig. 1 and the exhaust system from Fig. 1 and Fig. 2. Fig. 1 is a functional block diagram of a vehicle 100 according to an exemplary embodiment. As described in more detail below, the vehicle 100, in various embodiments, includes, among other components, an exhaust system 110 and a control system 102 that controls the storage of oxygen in the exhaust system 110. In certain embodiments, the vehicle 100 comprises an automobile. In certain other embodiments, the vehicle 100 comprises one or more other types of vehicles, such as one or more buses, trains, trucks, watercraft, aircraft or the like, and / or one or more other types of mobile platforms. In the illustrated embodiment, the vehicle 100 comprises a body 104 mounted on a chassis 106. The body 104 essentially encloses other components of the vehicle 100. The body 104 and the chassis 106 can together form a frame. The vehicle 100 also includes a plurality of wheels 112. The wheels 112 are each rotatably coupled to the chassis 106 near a respective corner of the body 104 to enable the movement of the vehicle 100. In one embodiment, the vehicle 100 includes four wheels 112, although this may vary in other embodiments (for example, for trucks and certain other vehicles). A drive system 108 is mounted on the chassis 106 and drives the wheels 112, for example, via axles 114. The drive system 108 preferably comprises a drive unit. In certain embodiments, the drive system 108 provides drive according to a driver's intention, as manifested by the driver's use of an accelerator pedal. Also in certain embodiments, the drive system 108 can also provide automatic drive control under suitable circumstances according to instructions provided by the control system 102. As shown in Fig. 1, the drive system 108 includes an engine 109 in various embodiments. In certain exemplary embodiments, the engine 109 comprises an internal combustion engine coupled to a transmission. In certain embodiments, the drive system 108 can vary and / or two or more drive systems 108 can be used. For example, the vehicle 100 can also include any one of, or a combination of, a number of different types of drive systems, such as, for example, a gasoline or diesel-powered internal combustion engine, a flex-fuel vehicle (FFV) engine (i.e., using a mixture of gasoline and alcohol), an engine powered by a gaseous compound (e.g., hydrogen and / or natural gas), an internal combustion / electric hybrid engine, and an electric motor. As shown in Fig. 1, the vehicle 100 also includes an exhaust system 110. In various embodiments, the exhaust system 110 includes a plurality of catalytic converters 111 that treat gases from the engine 109 before they leave the vehicle 100. In various embodiments, the exhaust system 110 utilizes both oxidation and reduction reactions as part of the treatment of the gas from the engine 109. In particular, in various embodiments: (i) carbon monoxide reacts with oxygen to form carbon dioxide as part of an oxidation reaction; and (ii) nitrogen oxides are reduced to nitrogen and oxygen as part of a reduction reaction. In various embodiments, maintaining an appropriate oxygen content in the various catalytic converters of the exhaust system 110 is important for optimal functioning of the exhaust system 110. With reference to Fig. 2, an exemplary illustration of the exhaust system 110 according to an exemplary embodiment is shown. In the embodiment of Fig. 2, the exhaust system 110 includes three catalytic converters 111, namely: (i) a first catalytic converter 201; (ii) a second catalytic converter 202; and (iii) a third catalytic converter 203. In the illustrated embodiment: (i) the first catalytic converter 201 receives gas flow directly from the engine 109 and initially treats the gas flow; (ii) the second catalytic converter 202 receives gas flow directly from the first catalytic converter 201 and further treats the gas flow; and (iii) the third catalytic converter 203 receives gas stream directly from the second catalytic converter 202 and completes the treatment of the gas stream before the gas stream leaves the vehicle 100 as exhaust gas.In the illustrated embodiments, the first catalytic converter 201 is monitored with respect to oxygen storage, whereas the second catalytic converter 202 and the third catalytic converter 203 are unmonitored with respect to oxygen storage. It is understood, however, that the number and configuration of the catalytic converters 111 can vary in different embodiments. Referring again to Fig. 1, the control system 102 in the illustrated embodiment is coupled to both the drive system 108 (including the motor 109 thereof) and the exhaust system 110. In various embodiments, the control system 102 controls the operation of the exhaust system 110, including the storage of oxygen in the catalytic converters 111, including as further explained below in connection with the process 300 from Fig. 3. As shown in Fig. 1, the control system 102, in various embodiments, includes a sensor arrangement 120, actuators 130, and a controller 140. In certain embodiments, the control system 102 may also include one or more other components. Additionally, in certain embodiments, certain components shown in Fig. 1 as part of the control system 102 (including the sensor arrangement 120 and / or the actuators 130) may, in certain examples, also be considered part of the exhaust system 110. In various embodiments, the sensor arrangement 120 includes different sensors used for the operation of the exhaust system 110 and for controlling the oxygen storage in the catalytic converters 111 thereof. In the illustrated embodiment, the sensor arrangement 120 includes one or more oxygen sensors 122, flow sensors 124, and temperature sensors 126. In various embodiments, the sensor arrangement 120 may also include one or more other sensors 128. In various embodiments, the oxygen sensors 122 obtain oxygen sensor data by measuring oxygen saturation values ​​in or with respect to one or more of the catalytic converters 111. In particular, in certain embodiments, the oxygen sensors 122 include a plurality of oxygen sensors 122 that measure oxygen saturation values ​​before and after the gas stream enters one or more specific catalytic converters 111. Referring again to Fig. 2, the oxygen sensors 122 in the illustrated embodiment include one or more pre-oxygen sensors 204 and post-oxygen sensors 206. In various embodiments, the pre-oxygen sensors 204 measure an oxygen saturation value of the gas stream as it enters a specific catalytic converter 111, whereas the post-oxygen sensors 206 measure an oxygen saturation value of the gas stream as it exits the specific catalytic converter 111. In the embodiment shown in Fig. 2, the pre-oxygen sensors 204 and the post-oxygen sensors 206 are positioned at an inlet and an outlet, respectively, of the first catalytic converter 201. In this embodiment, the oxygen sensors 122 thus monitor the oxygen saturation value in the first catalytic converter 201.In certain other embodiments, one or more other catalytic converters 111 (e.g. the second catalytic converter 202 and / or the third catalytic converter 203) can be similarly monitored with respect to the oxygen saturation value therein, instead of or in addition to the first catalytic converter 201 from Fig. 2. Referring again to Fig. 1, the flow sensors 124 in various embodiments obtain flow sensor data by measuring one or more parameter values ​​of the gas flow of the exhaust system 110, including the gas flow entering and / or leaving the various catalytic converters 111. In particular, the flow sensors 124 in certain embodiments measure the flow velocity, flow uniformity, and mass flow rate of the gas flow and / or measure gas flow parameters that are used by the controller 140 to calculate these values. Furthermore, in various embodiments, the temperature sensors 126 obtain temperature sensor data by measuring temperature values ​​of the gas flow in the exhaust system 110, including the gas flow entering and / or leaving the various catalytic converters 111. In particular, in certain embodiments, the temperature sensors 126 measure temperature values ​​of the gas flow. In certain embodiments, the temperature sensors 126 can also measure temperature values ​​within one or more of the catalytic converters. In addition, in certain embodiments, the sensor arrangement 120 may also include one or more other sensors 128, which may include (for example) one or more transmission and / or gear sensors of the vehicle 100 (e.g., relating to whether the engine is switched on, the current gear of the vehicle 100, an engine state including engine speed and load, etc.), valve sensors used to detect when one or more valves of the exhaust system 110 and / or the drive system 108 are open or closed, and / or one or more input sensors configured to receive input values ​​from a driver or other user of the vehicle 100 (e.g., via the action of an accelerator pedal or other vehicle component) or the like. In various embodiments, the control unit 140 is coupled to the sensor arrangement 120 and to the exhaust system 110. In certain embodiments, the control system 102 is also coupled to the drive system 108 and / or to one or more other components of the vehicle 100. Also in various embodiments, the control unit 140 comprises a computer system (hereinafter also referred to as computer system 140) and includes a processor 142, a memory 144, an interface 146, a storage device 148, and a computer bus 150. In various embodiments, the control unit (or the computer system) 140 controls the operation of the exhaust system 110, including the oxygen storage in its catalytic converters 111. In various embodiments, the control unit 140 provides these and other functions according to the steps of the process 300 shown in Fig. 3 and as described below in connection therewith. In various embodiments, the controller 140 (and in certain embodiments, the control system 102 itself) is arranged within the body 104 of the vehicle 100. In one embodiment, the control system 102 is mounted on the chassis 106. In certain embodiments, the controller 140 and / or the control system 102 and / or one or more components thereof can be arranged outside the body 104, for example, on a remote device, in the cloud, or on another device where image processing is performed remotely. It is understood that the control unit 140 may differ in other ways from the embodiment shown in Fig. 1. For example, the control unit 140 may be coupled to or otherwise utilize one or more remote computer systems and / or other control systems, for example as part of one or more of the devices and systems of the vehicle 100 identified above. In the illustrated embodiment, the computer system of the controller 140 comprises a processor 142, a memory 144, an interface 146, a storage device 148, and a bus 150. The processor 142 performs the calculation and control functions of the controller 140 and can comprise any type of processor or multiple processors, individual integrated circuits such as a microprocessor, or any suitable number of integrated circuit devices and / or printed circuit boards working together to perform the functions of a processing unit. During operation, the processor 142 executes one or more programs 152 contained in the memory 144 and, as such, controls the general operation of the controller 140 and the computer system of the controller 140, generally when performing the processes described herein, such as the process 300 shown in Fig. 3 and as further described below in connection therewith. The memory 144 can be any type of suitable memory. For example, the memory 144 can include various types of dynamic random-access memory (DRAM) such as SDRAM, the various types of static RAM (SRAM), and the various types of non-volatile memory (PROM, EPROM, and Flash). In certain examples, the memory 144 is located on the same computer chip as the processor 142 and / or is located together on the same chip. In the illustrated embodiment, the memory 144 stores the aforementioned program 152 together with one or more stored values ​​154 (e.g., including, in various embodiments, thresholds for the process 300 of Fig. 3). The bus 150 serves to transmit programs, data, status, and other information or signals between the various components of the controller 140's computer system. The interface 146 enables communication with the controller 140's computer system, for example, from a system driver and / or another computer system, and can be implemented using any suitable method and device. In one embodiment, the interface 146 receives the various data from the sensor arrangement 120. The interface 146 can include one or more network interfaces for communication with other systems or components. The interface 146 can also include one or more network interfaces for communication with technicians and / or one or more memory interfaces for connecting to storage devices such as the storage device 148. The storage device 148 can be any suitable type of storage device, including various types of random-access memory and / or other storage devices. In one exemplary embodiment, the storage device 148 comprises a program product from which the memory 144 can receive a program 152 executing one or more embodiments of the process 300 from Fig. 3, as described below in connection therewith. In another exemplary embodiment, the program product can be stored directly in the memory 144 and / or on a disk (e.g., disk 156), such as those mentioned below, and / or be accessed by other means. Bus 150 can be any suitable physical or logical means for connecting computer systems and components. This includes, but is not limited to, direct hard-wired connections, fiber optic, infrared, and wireless bus technologies. During operation, program 152 is stored in memory 144 and executed by processor 142. It is understood that, while this exemplary embodiment is described in the context of a fully functioning computer system, those skilled in the art will recognize that the mechanisms of the present description are capable of being distributed as a program product with one or more types of non-volatile, computer-readable signal-carrying media used to store the program and its instructions, and to carry out its distribution, such as a non-volatile, computer-readable medium carrying the program and containing computer instructions stored therein to instruct a computer processor (such as Processor 142) to execute the program. Such a program product can take a variety of forms, and the present description applies equally regardless of the specific type of computer-readable signal-carrying media used to carry out the distribution.Examples of signal-carrying media include: writable media, such as floppy disks, hard drives, memory cards, and optical discs, and transmission media, such as digital and analog communication links. It is understood that cloud-based storage and / or other technologies may also be used in certain embodiments. Likewise, it is understood that the computer system of the controller 140 may also differ in other ways from the embodiment shown in Fig. 1, for example, in that the computer system of the controller 140 may be coupled with or otherwise utilize one or more remote computer systems and / or other control systems. Fig. 3 is a flowchart for a process 300 for controlling the storage of oxygen in an exhaust system of a vehicle according to exemplary embodiments. In various embodiments, the process 300 can be implemented in conjunction with the vehicle 100 from Fig. 1 and including the control system 102 therein from Fig. 1 and the exhaust system 110 from Figs. 1 and 2. As shown in Fig. 3, process 300 begins at 302. In various embodiments, process 300 begins at 302 when the vehicle 100 starts operating (e.g., when the engine 109 is switched on). In one embodiment, the steps of process 300 are carried out continuously while the vehicle 100 is in operation (e.g., while the engine 109 is running). In various embodiments, oxygen storage values ​​are modeled (step 304). In particular, in various embodiments, oxygen storage values ​​are modeled for each catalyst and / or each zone of each of the catalytic converters 111. Also in various embodiments, as part of step 304, sensor data are obtained from each of the sensors of the sensor arrangement 120 of Fig. 1 (e.g.,including with respect to parameters relating to the catalytic converters 111, including oxygen saturation of the gas stream entering and leaving the monitored catalytic converters 111, and further including flow velocity, flow uniformity and mass flow rate of the gas stream, and further including temperature of the gas stream and / or within the catalytic converters 111, in addition to an operating state of an engine of the vehicle, including an engine speed and load, and a voltage output from the one or more oxygen sensors 122). In various embodiments, the modeling is also performed by the processor 142 of Fig. 1 using the sensor data in combination with one or more physical boundary conditions (e.g., as stored values ​​156 in the memory 144 of Fig. 1) using a physics-based model. Additionally, in various embodiments, the modeling is used to estimate the oxygen saturation values ​​in the unmonitored catalytic converters 111 (e.g., in the example of Fig. 2, the second catalytic converter 202 and the third catalytic converter 203, which do not have oxygen sensors 122 for direct measurement of oxygen saturation in the example shown in Fig. 2).In addition, in various embodiments, modeling is carried out and the parameter values ​​are determined based on oxygen storage values ​​for each specific zone at a given time as a function of physical principles, thereby providing an estimate of how oxygen-rich the exhaust gas stream is (i.e., in terms of the air-fuel ratio). Also in various embodiments, according to the modeling performed by the processor 142, the model is configured to understand the hardware design parameters in order to determine catalyst zone formation, such as catalyst and pipe dimensions and sensor placement within the exhaust aftertreatment system. As also shown in Fig. 3, in various embodiments, determinations are made as to whether the oxygen saturation value of the catalyst is greater than a predetermined threshold (step 306). In particular, in various embodiments, the processor 142 of Fig. 1 determines for each specific zone whether the oxygen saturation value (OSV) of the catalyst (which in certain embodiments may also be related to the oxygen storage value of the catalyst) is greater than a predetermined threshold corresponding to a desired OSV value. In certain embodiments, the predetermined threshold of step 306 includes a maximum desired OSV value (e.g., a maximum value within a range of OSV values ​​in which the catalytic converters 111 are expected to function correctly with optimal performance and efficiency in certain embodiments).In various embodiments, the predetermined threshold corresponds to a minimum and / or maximum OSV threshold of the efficient operating range, which would be determined by the characteristics of the specific catalyst washcoat and platinum group metal loading and distribution within the catalyst. Additionally, in certain embodiments, the specific operating point can influence the optimal minimum and / or maximum. In one exemplary embodiment, an exemplary range encompasses an OSV value of thirty percent to seventy percent (30-70%) of the total OSV; however, this can vary in other embodiments. Also in certain embodiments, the predetermined threshold is stored in the memory 144 of Fig. 1 as a stored value 154 therein. In various embodiments, if step 306 determines that the catalyst's OSV values ​​do not exceed the predetermined threshold, the process proceeds to step 304, as shown in Fig. 3. In various embodiments, this occurs when the OSV value of a specific zone and / or catalytic converter exceeds its respective predetermined threshold. When process 300 returns to step 304 in this matter, also in various embodiments, steps 304-306 are then repeated in new iterations until, in a subsequent iteration of step 306, it is determined that one or more OSV values ​​exceed the predetermined threshold. In various embodiments, if in step 306 it is determined that the OSV value of the catalyst exceeds the predetermined threshold (e.g., if in certain embodiments the OSV value in at least one zone exceeds its predetermined threshold), it is determined in various embodiments whether a purge request has been received (step 308). In various embodiments, this determination is made by the processor 142 of Fig. 1 using sensor data on whether an oxygen purge request has been received. In certain embodiments, for example, an oxygen purge request is triggered either by sensor data or model data that exceeds the predetermined threshold. In various embodiments, if step 308 determines that no flushing request has been received, the process proceeds to step 304, as shown in Fig. 3. In various embodiments, steps 304-308 are then repeated in new iterations until, in a subsequent iteration of step 308, it is determined that a flushing request has been received. In various embodiments, once it is determined in step 308 that a purge request has been received, an oxygen purge strategy is selected (step 310). In various embodiments, during step 310, the processor 142 of Fig. 1 selects one of a variety of oxygen purge strategies based on the sensor data, in addition to the modeling and resulting oxygen saturation values ​​from step 304. Also in various embodiments, during step 310, the processor 142 selects the oxygen purge strategy from the following potential strategies: (i) applying fuel, for example, by open-valve injection; (ii) changing when fuel is applied; (iii) applying a bias (e.g.,(iv) biasing a monitored volume oxygen sensor (PO2) downstream of the catalyst, such as by shifting the control system to apply more fuel; (iv) manipulating a velocity of the exhaust gas flow (e.g., in certain embodiments by manipulating the wastegate of a turbocharger); and (v) modifying one or more locations on the catalytic converter 111 with which the exhaust gas flow will come into contact, such as by redistributing the exhaust gas flow to contact one cylinder part of the catalytic converter 111 and not the other, such as when one side already has a higher oxygen saturation than the other, and so on), among other possible strategies.In certain embodiments, other possible enrichment strategies may also include the following, among other potential strategies: reducing the airflow through the engine 109 and therefore through the exhaust system 110; manipulating one or more valves to perform a cylinder deactivation function for deceleration; modulating the load applied via the transmission; activating one or more cylinders; changing the oxygen saturation of the supply gas; and so on. In various embodiments, the processor 142 selects the oxygen purge strategy from these options based on the results of the modeling in step 304 and taking into account the physical parameters of the system, including flow velocity, mass flow rate, temperature, oxygen saturation, and uniformity. In certain embodiments, this selection also includes other factors such as the operating state of the vehicle's engine, including its speed and load, and the voltage output from one or more oxygen sensors 122. Also in various embodiments, the processor 142 selects the chosen strategy in a way that restores the oxygen saturation value to its desired level, in other words, to enable optimal efficiency of the catalytic converter 111.In addition, in certain embodiments, the selection of the oxygen purge strategy is performed separately for each catalytic converter 111 and / or each zone, so that different enrichment strategies can potentially be selected for different catalytic converters 111 and / or zones. Also in various embodiments, depending on the selected strategy, different actuators 130 from Fig. 1 would be used according to instructions provided by the processor 142. In certain embodiments, the optimal oxygen purge strategy may differ between two or more zones of the exhaust aftertreatment system. In certain such embodiments, arbitration is used to determine the strategy that best restores the overall system to optimal emission conversion efficiency. In various embodiments, the selected oxygen purge strategy is implemented (step 312). In particular, in various embodiments, during step 312, the specific strategy selected in step 310 is implemented according to instructions provided by the processor 142 of Fig. 1 and implemented via one or more actuators 130 of Fig. 1 based on the specific enrichment strategy that was selected. Similarly, in various embodiments in which different respective strategies for different catalytic converters 111 and / or different zones are selected in step 310, these different respective strategies are also implemented in step 312 for the different catalytic converters and / or different zones.Additionally, in certain embodiments, once the one or more oxygen purge strategies have been determined, the one or more oxygen purge strategies are implemented via the instructions provided by the processor 142, regardless of the operating state of the vehicle's fuel control system. In various embodiments, it is then determined whether the OSV target is met (step 314). In particular, in various embodiments, the processor 142 determines separately for each catalytic converter 111 and / or each zone whether an updated, current OSV value is within an optimal range (e.g., based on whether the OSV value is now less than or equal to the predetermined threshold from step 306 in an exemplary embodiment). If, in various embodiments, it is determined in step 314 that one or more of the OSV targets have not been met (e.g., that one or more of the current OSV values ​​are still greater than the predetermined threshold from step 306), then process 300 returns to step 310 while the selected purge enrichment strategy continues. In various embodiments, steps 312-314 are repeated in this manner in various iterations until, in an iteration of step 314, it is determined that each of the OSV targets has been met. In various embodiments, if it is determined in an iteration of step 314 that each of the OSV objectives has been met, then process 300 returns to step 304 while new sensor data is acquired and new determinations are made in a new iteration. Also in certain embodiments, process 300 terminates as soon as motor 109 is switched off. Accordingly, methods, systems, and vehicles are provided for controlling the storage of catalyst oxygen in vehicle catalytic converters. In various embodiments, the oxygen saturation values ​​for each of the catalytic converters are determined and monitored, including those without oxygen sensors (i.e., catalytic converters that would otherwise be "unmonitored"). Furthermore, in various embodiments, oxygen purging and adjustments to oxygen saturation are performed not only based on fuel enrichment and monitored volumes, but also based on other parameters, including mass flow, mass velocity, oxygen target control, and injection timing.Furthermore, in various embodiments, the techniques described herein are employed when oxygen saturation values ​​exceed a certain predetermined threshold, as determined by the processor using a physics-based model, regardless of whether a fuel cut-off event has occurred (e.g., regardless of whether a driver has lifted their foot off the accelerator pedal). Accordingly, in various embodiments, the monitoring and correction of oxygen saturation values ​​are also performed continuously while the engine is running, regardless of whether a fuel cut-off has occurred.In various embodiments, this also allows the oxygen saturation values ​​to remain within a desired range, so that both oxygen and reduction reactions can continue to occur for the catalytic converters and so that the catalytic converters can continue to operate at peak efficiency. It is understood that the systems, vehicles, and procedures may differ from those depicted in the figures and described herein. For example, vehicle 100, including the control system 102, the exhaust system 110, and other components thereof, may differ from that depicted in Figures 1 and 2 and described above in conjunction with them. It is likewise understood that the steps of the processes and implementations of Figure 3 may differ from those depicted in Figure 3 and described above in conjunction with it, and / or may be carried out in a different sequence.

Claims

Method comprising: Obtaining sensor data on the operation of one or more catalytic converters (111) of a vehicle (100) via one or more sensors (128) of the vehicle (100); Determining, via a processor (142) of the vehicle (100) using the sensor data in combination with a physics-based model, an oxygen saturation value of a catalyst of the one or more catalytic converters (111); Determining, via the processor (142), whether the oxygen storage value of the catalyst exceeds a predetermined threshold; and Implementing one or more oxygen purge strategies, via instructions provided by the processor (142), when the oxygen saturation value of the catalyst exceeds the predetermined threshold;wherein the oxygen saturation value is determined via the processor (142) based on each of the following: temperature of the gas flow, flow velocity of the gas flow, mass flow rate of the gas flow, flow uniformity of the gas flow, an operating state of an engine (109) of the vehicle (100) and a voltage output from the one or more sensors (128).; Method according to claim 1, wherein the one or more catalytic converters (111) comprise a plurality of catalytic converters (111) and the oxygen saturation value is determined via the processor (142) for each of the plurality of catalytic converters (111) using the sensor data and the physics-based model, regardless of whether each of the plurality of catalytic converters (111) includes oxygen sensors (122). The method of claim 1, further comprising: selecting, via the processor (142), one selected from a plurality of potential oxygen purge strategies based on the sensor data and the physics-based model; wherein the step of implementing one or more oxygen purge strategies comprises implementing the selected from the plurality of potential oxygen purge strategies according to instructions provided to and implemented by a specific one or more actuators of the vehicle (100), based on the selected from the plurality of potential oxygen purge strategies. Method according to claim 3, wherein the selection of the selected from the plurality of potential oxygen purge strategies is carried out by the processor (142) based on one or more of the following: temperature of the gas flow, flow velocity of the gas flow, mass flow rate of the gas flow, flow uniformity of the gas flow, an operating state of an engine (109) of the vehicle (100) and a voltage output from the one or more sensors (128). Method according to claim 3, wherein the selection of the selected from the plurality of potential oxygen purge strategies is carried out by the processor (142) based on each of the following: temperature of the gas flow, flow velocity of the gas flow, mass flow rate of the gas flow, flow uniformity of the gas flow, an operating state of an engine (109) of the vehicle (100) and a voltage output from the one or more sensors (128). The method of claim 1, wherein the acquisition of sensor data, the determination of the oxygen saturation value of the gas stream, the determination of whether the oxygen saturation value exceeds the predetermined threshold; and the implementation of one or more oxygen purge strategies are carried out continuously during the operation of an engine (109) of the vehicle (100), regardless of whether a fuel cut-off event has occurred for the vehicle (100). System comprising: one or more sensors (128) of a vehicle (100), wherein the one or more sensors (128) are configured to obtain sensor data on the operation of one or more catalytic converters (111) of the vehicle (100); and a processor (142) of the vehicle (100), wherein the processor (142) is coupled to the one or more sensors (128) and configured to enable at least the following: determining, using the sensor data in combination with a physics-based model, an oxygen saturation value of a catalyst of the one or more catalytic converters (111); determining whether the oxygen saturation value of the catalyst exceeds a predetermined threshold; and implementing one or more oxygen purge strategies, via instructions provided by the processor (142), when the oxygen saturation value of the catalyst exceeds the predetermined threshold.wherein the processor (142) is configured to perform the determination of the oxygen saturation value based on each of the following: temperature of the gas flow, flow velocity of the gas flow, mass flow rate of the gas flow, flow uniformity of the gas flow, an operating state of an engine (109) of the vehicle (100) and a voltage output from the one or more sensors (128).;

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