Air handling system and control for internal combustion engine operating in miller cycle

Abstract

A system includes an internal combustion engine (100) including a valve train (120) including one or more intake valves and one or more exhaust valves that may be operated in a Miller cycle. The electric turbine motor (180) is electronically controllable to boost the output from the lower pressure turbocharger to the higher pressure turbocharger. The electronic control system is configured to control the electric turbine motor in response to the transient condition to boost an intake flow pressure of the internal combustion engine during the transient condition.

Description

Technical Field

[0001] The present application relates generally to engine air handling systems and controls, and more particularly, but not limited to, to air handling systems and controls for internal combustion engines operating on a Miller cycle. Background Art

[0002] Engines may utilize different combustion cycles appropriate for different operating conditions. For example, turbocharging and / or the Miller cycle may be employed on one or more cylinders of an engine to improve fuel efficiency, thermal management, and engine power in steady state conditions. Many proposals have been made for controlling such engines and systems. Existing approaches have many shortcomings, deficiencies, and unmet needs, including those regarding transient operation and emissions. There remains a significant need for the unique apparatus, methods, systems, and techniques disclosed herein.

[0003] Disclosure of Example Embodiments

[0004] For the purpose of clearly, concisely and accurately describing the exemplary embodiments of the present disclosure, the manner and process of making and using the present disclosure, and to enable the implementation, making and using of the present disclosure, reference will now be made to certain exemplary embodiments, including those illustrated in the figures, and specific language will be used to describe the present disclosure. However, it should be understood that no limitation on the scope of the present invention is thereby created, and the present invention includes and protects such changes, modifications and further applications of the exemplary embodiments as will occur to those skilled in the art. Summary of the invention

[0005] Multiple embodiments are disclosed relating to air handling control of an internal combustion engine operating in a Miller cycle. As used herein, a Miller cycle includes an engine cycle in which an overexpansion cycle is employed. In an overexpansion cycle, the effective compression ratio is less than the effective expansion ratio and is achieved by advancing (EIVC) or retarding (LIVC) the intake valve closing relative to bottom dead center of the intake stroke. The primary effect of EIVC and LIVC is to reduce temperatures at the end of the compression stroke. Lower temperatures enable the use of a higher geometric compression ratio, which results in a longer expansion ratio and efficiency benefits.

[0006] One embodiment of the present disclosure is a unique device for providing air handling and / or air handling control for an internal combustion engine operating with a Miller cycle. Another embodiment is a unique system for providing air handling and / or air handling control for an internal combustion engine operating with a Miller cycle. A further embodiment is a unique method of controlling an air handling system for an internal combustion engine operating with a Miller cycle. Further embodiments, forms, objects, features, advantages, aspects and benefits will become apparent from the following description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a schematic block diagram of an internal combustion engine system having an internal combustion engine including one or more cylinders operating in a Miller cycle and a multi-stage turbocharger system.

[0008] Figure 2 It is an electronic control system and Figure 1 Schematic block diagram of an internal combustion engine.

[0009] Figure 3 It is a graphic Figure 1 Logic diagram of an example turbocharger system control logic for a multi-stage turbocharger system and an internal combustion engine.

[0010] Figure 4 is a logic diagram illustrating a further example of turbocharger system control logic.

[0011] Figure 5 It is used to control and Figure 1 A schematic flow chart of the operation of an internal combustion engine combined with a multi-stage turbocharger system. DETAILED DESCRIPTION

[0012] For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the accompanying drawings and specific language will be used to describe the embodiments. It will be understood, however, that it is not intended to limit the scope of the invention thereby, and any alterations and further modifications of the illustrated embodiments as would normally occur to one skilled in the art to which the invention relates and any further applications of the principles of the invention as illustrated herein are contemplated herein.

[0013] refer to Figure 1 , the internal combustion engine system 100 includes an internal combustion engine 102 and a multi-stage turbocharger system 150 illustrated in schematic form. The internal combustion engine system 100 includes a fuel source 104 that can operate with the internal combustion engine 102 to provide fuel to one or more cylinders 108 of the engine 102. For the system 100, any type of fuel is contemplated, including diesel, gasoline, gaseous fuels, hydrogen fuels, and dual fuel arrangements. In addition, one or more electric turbine motors 180 can be provided to output power to propel a vehicle propelled by the engine 102 and / or to assist in providing power to one or more other components of the system 100 (such as to a hybrid vehicle).

[0014] The engine 102 is connected to an intake system 110 for providing an intake flow to the engine 102 and an exhaust system 112 for outputting exhaust gas in the form of an exhaust flow. In the illustrated embodiment, the engine 102 is shown with only a single cylinder 108, but any number and arrangement of cylinders 108 is contemplated, and the system 100 is not limited to Figure 1 The quantity and arrangement shown in .

[0015] The engine 102 includes an engine block 116 that at least partially defines (one or more) cylinders 108. A piston 118 may be slidably disposed within each cylinder 108 to reciprocate between a top dead center position and a bottom dead center position while rotating a crankshaft (not shown). Each of the cylinders 108, its corresponding piston 118, and a cylinder head 122 form a combustion chamber 124. Each cylinder 108 may also receive fuel from a fuel injector coupled to the fuel source 104, and if spark ignited, from a spark plug for controlling the timing and initiation of the combustion process. Each cylinder 108 includes one or more intake valves 130 and one or more exhaust valves 132 that are part of the valve train 120.

[0016] The valve train 120 may also include a camshaft (not shown) and other components to control the opening and closing of the intake valve 130 and the exhaust valve 132. The valve train 120 may be implemented in a variety of other forms, including a plurality of additional components, such as rocker arms, lash adjusters, bearing surfaces, gears, separate camshafts for the intake cam lobes and the exhaust cam lobes, and other components as will occur to those skilled in the art having the benefit of and understanding the present disclosure. The valve train 120 may be configured to time the opening and closing of the intake valve 130 and the exhaust valve 132 relative to the positioning of the piston 118 between the top dead center and the bottom dead center positions to control the entry of the intake flow and the exit of the exhaust flow. In an embodiment, the valve train 120 opens the intake valve 130 to provide an EIVC or LIVC relative to the bottom dead center of the intake stroke of the piston 118 so that the cylinder(s) 108 operate in a Miller cycle.

[0017] In one embodiment, the engine 102 is a four-stroke engine. That is, for each complete engine combustion cycle (i.e., for every two complete crankshaft rotations), each piston 118 of each cylinder 108 moves through an intake stroke, a compression stroke, a combustion or power stroke, and an exhaust stroke. Thus, during each complete combustion cycle of each cylinder 108, intake air is drawn from the intake manifold 126 into each combustion chamber 124, and exhaust gas is supplied to the exhaust manifold 128.

[0018] The engine 102 includes (one or more) cylinders 108 connected to an intake system 110 to receive an intake flow. (One or more) cylinders 108 are connected to an exhaust system 112 to release exhaust gas produced by the combustion of (one or more) fuels in the combustion chamber 124. The exhaust system 112 provides the exhaust flow to a multi-stage turbocharger system 150. The turbocharger system 150 includes multiple turbochargers to provide higher pressure and lower pressure turbocharger stages that use energy from the exhaust flow to compress the intake flow. In addition, the exhaust system 112 can be connected to the intake system 110 by means of one or both of a high pressure exhaust gas recirculation (EGR) system and a low pressure EGR system (not shown).

[0019] The intake system 110 includes one or more intake air supply conduits 114 extending from the turbocharger system 150 and connected to the intake manifold 126, which distributes the charge flow to the cylinder(s) 108 of the engine 102. The exhaust system 112 is also connected to the engine 102 via an engine exhaust manifold 128. The exhaust system 112 includes an exhaust conduit 130 extending from the exhaust manifold 128 to the turbocharger system 150. In one embodiment, the exhaust conduit 130 is flow-coupled to the exhaust manifold 128 and may also include one or more intermediate flow passages, conduits, or other structures. A controllable wastegate 132 or other suitable bypass in the exhaust conduit 130 is operable to selectively bypass at least a portion of the exhaust flow from the one or more turbines of the turbocharger system 150 to reduce boost pressure and engine torque under certain operating conditions.

[0020] An aftertreatment system 138 may be coupled to the outlet conduit 136. The aftertreatment system 138 may include, for example, a three way catalyst (TWC), an oxidation device (DOC), a particulate removal device (DPF, CDPF), a constituent absorber or reducer (SCR, AMOX, LNT), a reductant system, and other components, if desired.

[0021] The turbocharger system 150 includes a lower pressure first stage turbocharger 152 and a higher pressure second stage turbocharger 154. More than two stages are contemplated in other turbocharger embodiments. The first stage turbocharger 152 includes a first compressor 156 in the intake system 110 and a first turbine 158 in the exhaust system 112. The first turbine 158 is connected to the first compressor 156 by a shaft 160 and is operable to drive the first compressor 156 with exhaust gas flow. The first compressor 156 receives an intake flow in a non-compressed state and outputs a compressed intake flow to the second stage turbocharger 154.

[0022] In addition, the electric turbine motor 180 can be selectively coupled to the shaft 160 of the first stage turbocharger 152 to boost the pressure of the compressed intake air flow output from the first compressor 156. As discussed further below, in response to transient conditions of the internal combustion engine 102, the electric turbine motor 180 can utilize the connection 168 ( Figure 2 ) (such as a clutch or any other suitable selectively engageable connection) is selectively engaged to shaft 160 to increase compression or boost the intake air flow from first compressor 156 to improve engine performance during Miller cycle operation, such as by improving combustion and reducing smoke. The electric turbine motor 180 can be powered by an electrical system 182 of the internal combustion engine system 100. In an embodiment, the electrical system 182 is a 48V / 24V DC electrical system.

[0023] The second stage turbocharger 154 includes a second compressor 162 in the intake system 110 and a second turbine 164 in the exhaust system 112. The second turbine 164 is connected to the second compressor 162 via a shaft 166 and is operable to drive the second compressor 162 using the exhaust flow received from the exhaust manifold 128. The second compressor 162 receives the intake flow in a compressed state from the first compressor 156 and outputs the further compressed intake flow to the intake manifold 126.

[0024] The turbochargers 152, 154 may be any suitable turbocharger known in the art, including variable geometry turbochargers and / or wastegate turbochargers. For example, the wastegate 132 provides a controllable bypass around the second turbine 164. One or more of the first compressor 156 and the second compressor 162 may also include a bypass.

[0025] The intake system 110 may further include an intercooler 140 located between the first compressor 156 and the second compressor 162. The intake system 110 may further include an aftercooler 142 located downstream of the second compressor 162 and upstream of the intake manifold 126. The intercooler 140 and / or the aftercooler 142 may be, for example, an air-to-air heat exchanger, an air-to-liquid heat exchanger, or a combination of both to facilitate transfer of thermal energy to or from the flow directed to the engine 102. The intake system 110 may further include an intake throttle (not shown).

[0026] In operation of the internal combustion engine system 100, fresh air is supplied to the first compressor 156. The fresh air flow or combined flow may be filtered, unfiltered, and / or conditioned in any known manner before or after mixing with the EGR flow (when provided). The intake air flow is pressurized by the first compressor 156 and delivered to the second compressor 162 through the intercooler 140. The first compressor 156 may be boosted by the electric turbine motor 180 during transient conditions. The pressurized intake air flow is further pressurized by the second compressor 162 and flows to the intake manifold 126 through the aftercooler 142.

[0027] In any embodiment, the fuel provided to the cylinder(s) 108 from the fuel source 104 is controlled by an electronic control system (ECS) 200 to control the fuel flow based on, for example, engine speed, engine load, intake manifold pressure and temperature, and fuel pressure. The electric turbine motor 180 responds to control commands from the ECS 200 to selectively start and stop the electric turbine motor 180 to drive the first compressor 156 via shaft 160 and provide compression boost to the intake air flow of the engine 102.

[0028] Further references Figure 2 The engine 102 includes one or more engine sensors 202 that are operably connected to the ECS 200 to provide signals indicative of one or more engine operating parameters. The ECS 200 preferably includes one or more programmable microprocessors or microcontrollers of the solid-state integrated circuit type, and one or more non-transitory storage media configured to store instructions executable by the one or more microprocessors or microcontrollers.

[0029] The ECS 200 is configured to implement an electronic turbine motor (E-turbo) controller 204 that is configured to provide and output control commands to control the operation of the electric turbine motor 180. The E-turbo controller 204 can be configured to output commands to selectively engage and disengage the connection 168 between the electric turbine motor 180 and the shaft 160 in response to transient conditions of the engine 102. The turbine speed (TSP) sensor 208 can receive information about the speed of the shaft 160 from the first stage turbocharger 152. It should be understood that Figure 2 The control relationships between the aforementioned components are conceptually depicted using dashed arrows, and may be implemented using various communication hardware and protocols, such as one or more controller area networks (CAN) or other communication components.

[0030] Sensors 202 generally include one or more instances of the following sensors and associated input parameters. An engine speed sensor may be configured to provide an input parameter indicative of engine speed. An oxygen or lambda sensor may be configured to provide an input parameter indicative of an amount of concentration of oxygen of the intake charge and / or an air-fuel ratio of the intake charge. An injector rail pressure sensor may be configured to provide an input parameter indicative of fuel pressure of a fuel injector rail. An intake charge pressure sensor may be configured to provide an input parameter indicative of a pressure of an intake flow or charge. An intake charge temperature sensor may be configured to provide an input parameter indicative of a temperature of an intake flow or charge. A number of additional and / or alternative sensors and associated input parameters may be provided in sensors 202 as would occur to one of ordinary skill in the art having the benefit of and understanding the present disclosure.

[0031] The electronic turbine control parameters 206 may include one or more examples of multiple engine operating parameters indicative of transient events. Examples include engine speed, accelerator pedal position, output torque of the engine 102, start timing of injection, total fuel amount in all injections, fuel amount in the first pilot injection, timing of the first pilot injection, fuel amount in the second pilot injection, timing of the second pilot injection, timing of the main injection, fuel amount in the first post injection, timing of the first post injection, fuel amount in the second post injection, timing of the first post injection, and fuel amount in the main injection event. Such electronic turbine control parameters may be determined and provided by other controllers and control components of the ECS 200.

[0032] ECS200 can be implemented in any of a variety of ways, which combine or distribute control functions across one or more control units in various ways. ECS200 can execute operational logic that defines various control, management and / or regulation functions. The operational logic can be in the form of dedicated hardware (such as a hardwired state machine), an analog computing machine, programming instructions, and / or in different forms as those skilled in the art will think of. ECS200 can be provided as a single component or a collection of operably coupled components; and can include digital circuits, analog circuits, or a hybrid combination of these two types. When having a multi-component form, ECS200 can have one or more components that are remotely located in a distributed arrangement relative to other components. ECS200 may include multiple processing units that are arranged to operate independently in a pipeline processing arrangement, a parallel processing arrangement, or the like. It should be further understood that ECS200 and / or any of its constituent components may include one or more signal conditioners, modulators, demodulators, arithmetic logic units (ALUs), central processing units (CPUs), limiters, oscillators, control clocks, amplifiers, signal conditioners, filters, format converters, communication ports, clamps, delay devices, memory devices, analog-to-digital (A / D) converters, digital-to-analog (D / A) converters and / or different circuits or components for performing the desired communications as would occur to a person skilled in the art.

[0033] refer to Figure 3-4 , illustrates an example E-turbo controller 300 (also referred to herein as controller 300), which may be implemented in and executed by ECS200, E-Turbo controller 204, or another electronic control system. For example, controller 300 may be implemented and executed in whole or in part by E-turbo controller 204 alone or in combination with other electronic control system components. Controller 300 is configured to determine and provide an E-turbo command 390 that is configured and effective to control operation of electric turbine motor 180 in response to transient conditions to selectively provide boosted intake air flow pressure during Miller cycle operation of an engine system such as engine system 100. When applied to engine system 100 and ECS200, controller 300 may selectively provide boosted intake air flow pressure in response to transient operating conditions of engine 102.

[0034] The TSP sensor state 302 and the valid sensor state 312 are provided as inputs to an operator 322, which evaluates whether the TSP sensor state 302 is equal to the valid sensor state 312 and provides the result of the evaluation to an operator 332. The TSP sensor state 302 provides an indication of the operating state of a turbine speed sensor, such as the TSP sensor 208. The valid sensor state 312 provides an indication of the valid operating state of the TSP sensor 208. Thus, the evaluation performed by the operator 322 provides an indication of whether the TSP sensor is operating properly based on one or more criteria, such as an on flag, a diagnostic, a rationality assessment, an output range assessment, or other assessments, diagnostics, and flags, as will occur to one of ordinary skill in the art having the benefit of and understanding this disclosure.

[0035] The TSP estimate 304 and the TSP threshold 314 are provided as inputs to an operator 324, which evaluates whether the TSP estimate 304 is less than the TSP threshold 314 and provides the result of the evaluation to an operator 332. The TSP estimate 304 indicates a turbine speed value provided by the TSP sensor 208. The TSP threshold 314 indicates a maximum threshold or limit on turbine speed, beyond which engagement of the electric turbine motor 180 with the shaft 160 of the first stage turbocharger 152 is not permitted. The TSP threshold 314 may be configured based on the reliability or safety requirements of a given turbocharger design. In some forms, the TSP threshold 314 may be calibrated based on the requirements of a selected engine design or the requirements of a selected engine mission.

[0036] The engine speed 306 and the engine speed threshold 316 are provided as inputs to an operator 326, which evaluates whether the engine speed 306 is less than the engine speed threshold 316 and provides the result of the evaluation to an operator 332. The engine speed 306 indicates an engine speed value provided by an engine speed sensor. The engine speed threshold 316 indicates a maximum threshold or limit on engine speed, beyond which the engagement of the electric turbine motor 180 with the shaft 160 of the first stage turbocharger 152 is not permitted. The engine speed threshold 316 can be configured based on the reliability or safety requirements of a given engine and / or turbocharger design. In some forms, the engine speed threshold 316 can be calibrated based on the requirements of a selected engine design or the requirements of a selected engine mission.

[0037] Operator 332 performs a logical AND operation on the inputs received from operator 322, operator 324, and operator 326, and provides the result of the logical AND operation to operator 336 and logical NOT operator 365. Therefore, when the outputs of operator 322, operator 324, and operator 326 are all true, the output of operator 332 is also true, and when any one of the outputs of operator 322, operator 324, and operator 326 is false, the output of operator 332 is also false. It should be understood that, in addition to other logical terms that will occur to those skilled in the art with the benefit of this disclosure, the logical state or value referred to herein as "true" is synonymous with affirmative, enabled, or high logical states or values, and includes affirmative, enabled, or high logical states or values. Similarly, it should be understood that, in addition to other logical terms that will occur to those skilled in the art with the benefit of this disclosure, the logical state or value referred to herein as "false" is synonymous with negation, disablement, or low logical states or values, and includes negation, disablement, or low logical states or values.

[0038] The AFR 309 and the AFRE-Turbo on threshold 319 are provided as inputs to an operator 329, which evaluates whether the AFR 309 is less than the AFR E-Turbo on threshold 319 and provides the result of the evaluation to an operator 334. The AFR 309 indicates the air-fuel ratio of the charge being combusted by the engine system 100 as provided by a sensor, such as an oxygen or lambda sensor. The sensor may also be a virtual sensor, such as determining the AFR based on other parameters, such as air flow divided by fuel mass. The AFR E-Turbo on threshold 319 indicates a maximum threshold or limit on the air-fuel ratio of the charge being combusted by the engine system, beyond which boost compression intake airflow from the electric turbine motor 180 of the engine system is not permitted. The AFRE-Turbo on threshold 319 may be configured and selected based on emissions limits established with respect to a given engine design or with respect to an individual engine. For example, the AFRE-Turbo on threshold 219 may be configured and selected based on smoke or particulate emissions during engine transients for an engine operating in a Miller cycle, such as an EIVC or LIVC Miller cycle. Thus, the evaluation performed by the operator 329 provides an indication of whether the air-fuel ratio of the charge combusted by the engine system is of such magnitude that, such as during transient conditions, boost compression of the intake airflow by the electric turbine motor 180 is desired to achieve desired emissions performance.

[0039] OFC limit 318 is provided as an input to operator 334. Operator 334 performs a logical OR operation on the inputs received from operator 329 and OFC limit 318 and provides the result of the operation to operator 336. OFC limit 318 provides an indication that the engine system is operating an oxygen fuel control (OFC) mode. OFC mode is determined based on an assessment that the ratio of oxygen to fuel in the charge combusted by the engine system has exceeded a minimum threshold or limit. The ratio of oxygen to fuel in the charge combusted by the engine is related to the air-fuel ratio, but may be different due to the effects of EGR fraction, residual gas, and charge flow. A non-limiting example of OFC limit determination is found in U.S. Patent No. 6,508,241, issued on January 21, 2003, the disclosure of which is incorporated by reference.

[0040] The OFC limit 318 may correspond to an engine operating condition in which boost intake flow compression to the electric turbine motor 180 is desired to mitigate smoke or particulate emissions that may occur during engine transients for an engine operating in a Miller cycle, such as an EIVC or LIVC Miller cycle. Thus, the OFC limit 318 provides an indication of whether the oxygen-fuel ratio of the charge combusted by the engine system is of such magnitude that boost compression of the intake flow to the engine system is desired to achieve desired emissions performance.

[0041] like Figure 4 , the E-Turbo command 290 is provided as an input to a logical negation operator, which provides the logical inverse of the E-Turbo command as an output of a timer / counter 366. The timer / counter 366 may be configured and provided as a timer, a counter, a general timer counter, or in other forms as will occur to one skilled in the art. The timer / counter 366 also receives as an input a minimum E-Turbo off threshold 362, and compares the timing or count for which the value received from the logical negation operator 364 has been true to the minimum E-Turbo off threshold 362. When the minimum E-Turbo off threshold 362 has been reached or exceeded, the timer / counter 366 sets the value of the minimum E-Turbo off time 370 to true and provides it as an input to the operator 336. A true value of the minimum E-Turbo off time 370 indicates that the electric turbine motor 180 has been off or inactive for the minimum time or count required to allow activation of the electric turbine motor 180 to provide boost compression intake air flow operation, while a false value indicates the opposite.

[0042] Operator 336 performs a logical AND operation on the inputs it receives from operator 332, operator 334, and minimum E-Turbo off time 370, and provides the result of the operation to latch 380, which in turn sets the value of E-Turbo command 390. Thus, when the inputs received from operator 332, operator 334, and minimum E-Turbo off time 370 are all true, the value of E-Turbo command 390 is set to true.

[0043] The AFR 309 and the AFRE-Turbo off threshold 378 are provided as inputs to an operator 379, which evaluates whether the AFR 309 is greater than the AFR E-Turbo off threshold 378 and provides the result of the evaluation to an operator logic or operator 369. The AFR 309 indicates the air-fuel ratio of the charge being combusted by the engine system as provided by a sensor, such as an oxygen or lambda sensor. The AFR E-Turbo off threshold 378 indicates a threshold or limit on the air-fuel ratio of the charge being combusted by the engine system, beyond which boost intake flow compression of the engine system is not permitted. The AFRE-Turbo off threshold 378 can be configured and selected to avoid excess charge or intake flow that degrades fuel economy, and to reduce or limit E-Turbo on time to improve reliability. Thus, the evaluation performed by operator 379 provides an indication of whether the air-fuel ratio of the charge combusted by the engine system is of such a magnitude that the desired non-boosted intake air flow to the engine system from the electric turbine motor 180 achieves the desired fuel economy and reduces or limits the E-Turbo on time to improve reliability.

[0044] like Figure 4 , the E-Turbo command 390 is provided as an input to a timer / counter 367. The timer / counter 367 may be configured and provided as a timer, a counter, a general timer counter, or in other forms as will occur to one skilled in the art. The timer / counter 367 also receives as an input a maximum E-Turbo on threshold 375 and compares the timing or count for which the value of the input received from the E-Turbo command 390 has been true to the maximum E-Turbo threshold 375. When the maximum E-Turbo on threshold 375 has been reached or exceeded, the timer / counter 367 sets the value of the maximum E-Turbo on threshold 363 to true and provides it as an input to the logical OR operator 369. A true value of the maximum E-Turbo on time 363 indicates that the E-Turbo has been on or activated for a maximum allowed time or count, beyond which starting the electric turbine motor 180 is not permitted, while a false value indicates the opposite.

[0045] As indicated above, the output of the logical NOT operator 365, the output of the operator 329, and the maximum E-Turbo on time 363 are provided as inputs to the logical OR operator 369. The logical OR operator 369 performs a logical OR operation on the inputs received from the logical NOT operator 365, the operator 329, and the maximum E-Turbo on time 363, and provides the result of the operation to the latch 380, which in turn sets the value of the E-Turbo command 390. Therefore, when the value of any one of the inputs received from the logical NOT operator 365, the operator 329, and the maximum E-Turbo on time 363 is true, the value of the E-Turbo command 390 is set to false.

[0046] Reference now Figure 5 , a process 500 for operating the internal combustion engine system 100 described herein is shown. The process 500 begins at operation 502 to monitor operating conditions of the engine 102 that indicate a transient event or condition. For example, one or more sensors 202 connected to the ECS 200 may be operable to provide operating signals indicating one or more operating parameters or conditions of the engine 102 that indicate a transient event.

[0047] In other embodiments, operating conditions indicative of a transient event may include, for example, depression of an input device (such as an accelerator), a threshold increase in load applied to the internal combustion engine 102, a threshold increase in power demanded by the internal combustion engine 102, and / or a threshold increase in torque at an output shaft connected to the internal combustion engine 102. Thus, one or more sensors 202 connected to the ECS 200 may be operable to provide operating signals indicative of one or more operating parameters or conditions of the internal combustion engine 102 that are indicative of a transient event.

[0048] Process 500 continues from operation 502 to condition 504 to determine if a transient event is present. If condition 504 is negative, process 500 returns to continue monitoring operation 502. If condition 504 is positive, process 500 continues to operation 506 to initiate operation of electric turbine motor 180. In an embodiment, condition 504 may further include executing controller 300 to determine whether to operate electric turbine motor 180 in response to a transient event.

[0049] From operation 506, process 500 continues to conditional 508 to determine if the transient event is over. If conditional 508 is negative, process 500 returns to operation 506. If conditional 508 is positive, the process continues to operation 510 to terminate operation of electric turbine motor 180.

[0050] Using such Figure 1-5Systems and methods such as those shown in , can implement control strategies to improve engine response and performance during transient events. The electric turbine motor 180 can be used in response to transient events to provide pressurized air to (one or more) cylinders 108 for combustion and increased power. Therefore, during operation of the electric turbine motor 180, a target or desired engine output torque can be achieved more quickly than without the electric turbine motor.

[0051] Various aspects of the present disclosure are considered. In one aspect of the present disclosure, an internal combustion engine system is provided. The system includes an internal combustion engine having an intake system and an exhaust system. The internal combustion engine also includes at least one cylinder for receiving an intake flow for combustion to produce an exhaust flow. The system also includes a turbocharger system, the turbocharger system including a lower pressure turbocharger and a higher pressure turbocharger connected in series with each other. The lower pressure turbocharger includes a first turbine and a first compressor, the first compressor is driven by the exhaust flow through the first turbine to compress the intake flow, and the higher pressure turbocharger includes a second turbine upstream of the first turbine in the exhaust system. The higher pressure turbocharger includes a second compressor downstream of the first compressor in the intake system, and the second compressor is driven by the exhaust flow through the second turbine to further compress the compressed intake flow from the first compressor. The turbocharger system also includes an electric turbine motor connected to the first compressor, the electric turbine motor being operable to drive the first compressor to boost the output of the first turbine; and a controller configured to operate the electric turbine motor to drive the first compressor in response to a transient event of the internal combustion engine to provide compression boost of the intake air flow to the internal combustion engine.

[0052] In an embodiment, in response to the transient event, an electric turbine motor is connected to the shaft between the first compressor and the first turbine to drive the first compressor during the transient event.

[0053] In an embodiment, the system includes an intercooler in the intake system between the first compressor and the second compressor. In a refinement of this embodiment, the system includes an aftercooler in the intake system downstream of the second compressor. In a further refinement, a wastegate is provided around the second turbine.

[0054] In another embodiment, an internal combustion engine includes a valve train including one or more intake valves and one or more exhaust valves for at least one cylinder. In a refinement of this embodiment, one or more intake valves operate in a Miller cycle.

[0055] In a further improvement of the above embodiment, the controller is configured to operate the electric turbine motor to drive the first compressor in response to a transient when: an engine speed condition is met; a turbine speed condition is met; at least one of an air-fuel ratio (AFR) condition and an oxygen-fuel control (OFC) condition is met; and a minimum off time condition of the electric turbine motor is met.

[0056] In yet a further refinement of the system, one or more of the following is provided: an engine speed condition is met if the engine speed does not exceed an engine speed threshold; a turbine speed condition is met if an estimated turbine speed of the lower pressure turbocharger does not exceed a turbine speed threshold; an AFR condition is met if an air-fuel ratio of the internal combustion engine does not exceed an AFR threshold; an OFC condition is met if the internal combustion engine is operating in an oxygen-fuel control mode; and a minimum off time condition of the electric turbine motor is met if the electric turbine motor has been off or deactivated for at least a predetermined time.

[0057] In a further refinement, the electronic control system is configured to terminate operation of the electric turbine motor in any of the following situations: an engine speed condition is not satisfied; a turbine speed condition is not satisfied; an AFR condition is not satisfied; and a maximum on-time condition of the electric turbine motor is satisfied.

[0058] In a still further refinement, the maximum on-time condition of the electric turbine motor is met if the electric turbine motor has been on or activated for at least a predetermined time.

[0059] According to another aspect of the present disclosure, a device for controlling the operation of an internal combustion engine is provided. The internal combustion engine includes an intake system and an exhaust system, and at least one cylinder for receiving an intake flow from the intake system, for receiving fuel and generating an exhaust flow to the exhaust system. The engine further includes a valve mechanism associated with at least one cylinder, the valve mechanism including at least one intake valve for operating in a Miller cycle, and at least one exhaust valve. The engine also includes a multi-stage turbocharger system driven by the exhaust flow. The multi-stage turbocharger system includes a first compressor in the intake system, the first compressor coupled to an electric turbine motor and coupled to a first turbine. The multi-stage turbocharger further includes a second compressor located downstream of the first compressor and a second turbine located upstream of the first turbine coupled to the second compressor. The device for controlling the operation of the engine includes a controller operably connected to the internal combustion engine, the controller being configured to determine a transient event associated with the internal combustion engine, and in response to the transient event, start the operation of the electric turbine motor to provide compression boost of the intake flow through the first compressor.

[0060] In an embodiment, the controller is configured to receive input from one or more sensors providing one or more parameters indicative of an engine speed of the internal combustion engine, turbine speeds associated with the first compressor and the first turbine, AFR conditions, and OFC conditions.

[0061] In a refinement of the above embodiment, the controller is configured to operate the electric turbine motor to drive the first compressor in response to the transient in the following situations: in response to the engine speed not exceeding an engine speed threshold, an engine speed condition is satisfied; in response to the turbine speed not exceeding a turbine speed threshold, a turbine speed condition is satisfied; the AFR condition does not exceed the AFR threshold or the OFC condition operates in an oxygen-fuel control mode; and a minimum off time condition of the electric turbine motor is satisfied by the electric turbine motor being turned off or deactivated for at least a predetermined time.

[0062] In yet a further refinement of the above embodiment, the electronic control system is configured to terminate operation of the electric turbine motor in any of the following circumstances: the engine speed condition is not met; the turbine speed condition is not met; the AFR condition is not met; and the maximum opening time condition of the electric turbine motor is met.

[0063] According to another aspect of the present disclosure, a method includes: operating a valve train of an internal combustion engine in a Miller cycle; detecting a transient event during operation of the valve train in the Miller cycle; in response to the transient event, initiating operation of an electric turbo motor to boost compression of an intake air flow from a first stage of a multi-stage turbocharger system to a second stage of the multi-stage turbocharger system; and further compressing the boosted compressed intake air flow from the first stage with the second stage of the multi-stage turbocharger system upstream of the internal combustion engine.

[0064] In an embodiment, the method includes initiating operation of the electric turbine motor to increase compression of the intake air flow in response to the transient event only when: an engine speed condition is satisfied in response to the engine speed not exceeding an engine speed threshold; a turbine speed condition is satisfied in response to a turbine speed of the first stage not exceeding a turbine speed threshold; an AFR condition does not exceed an AFR threshold or an OFC condition operates in an oxygen-fuel control mode; and a minimum off time condition of the electric turbine motor is satisfied by the electric turbine motor being off or deactivated for at least a predetermined time.

[0065] In a refinement of the above embodiment, the method includes terminating operation of the electric turbine motor in any of the following situations: an engine speed condition is not met; a turbine speed condition is not met; an AFR condition is not met; and a maximum on time condition of the electric turbine motor is met.

[0066] In an embodiment, the method includes engaging an electric turbine motor to a shaft between a compressor and a turbine of a first stage of a multi-stage turbocharger in response to a transient event.

[0067] In an embodiment, the method includes intercooling a boosted compressed intake air flow between a first stage and a second stage of a multi-stage turbocharger system; and aftercooling the further compressed intake air flow downstream of the second stage of the multi-stage turbocharger system.

[0068] While the invention has been shown and described in detail in the drawings and foregoing description, it is to be considered illustrative and not restrictive, it being understood that only certain exemplary embodiments have been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.

[0069] It should be understood that although the use of words such as preferred, preferably, preferred or more preferred utilized in the above description indicates that the features so described may be more desirable, they may not be required, and embodiments lacking the features may be considered to be within the scope of the present invention, which is defined by the claims that follow. When reading the claims, it is intended that when words such as "a", "an", "at least one" or "at least a portion" are used, it is not intended to limit the claims to only one item unless expressly stated to the contrary in the claims. When the language "at least a portion" and / or "a portion" is used, the item may include a portion and / or the entire item unless expressly stated to the contrary.

Claims

1. An internal combustion engine system, the system comprising: An internal combustion engine including an intake system and an exhaust system, the internal combustion engine including at least one cylinder for receiving an intake flow for combustion to produce an exhaust flow; A turbocharger system comprising a lower pressure turbocharger and a higher pressure turbocharger connected in series with each other, wherein: The lower pressure turbocharger includes a first turbine and a first compressor driven by exhaust gas flow through the first turbine to compress intake air flow; the higher pressure turbocharger includes a second turbine located upstream of the first turbine in the exhaust system, and the higher pressure turbocharger includes a second compressor located downstream of the first compressor in the intake system, the second compressor being driven by exhaust gas flow through the second turbine to further compress a compressed intake flow from the first compressor; and an electric turbine motor connected to the first compressor, the electric turbine motor being operable to drive the first compressor to boost an output of the first turbine; and A controller is configured to operate the electric turbine motor to drive the first compressor to provide compression boost of intake air flow to the internal combustion engine in response to a transient event of the internal combustion engine.

2. The system according to claim 1, wherein: In response to the transient event, an electric turbine motor is connected to the shaft between the first compressor and the first turbine to drive the first compressor during the transient event. 3 . The system of claim 1 , further comprising an intercooler located in the intake system between the first compressor and the second compressor. 4 . The system of claim 3 , further comprising an aftercooler located in the intake system downstream of the second compressor. 5 . The system of claim 4 , further comprising a wastegate surrounding the second turbine.

6. The system of claim 1, wherein the internal combustion engine includes a valve train including one or more intake valves and one or more exhaust valves for at least one cylinder.

7. The system of claim 6, wherein one or more intake valves are operated in a Miller cycle.

8. The system of claim 7, wherein the controller is configured to operate the electric turbine motor to drive the first compressor in response to the transient condition when: The engine speed condition is met; The turbine speed condition is met; satisfying at least one of an air-fuel ratio (AFR) condition and an oxygen-fuel control (OFC) condition; and The minimum off-time condition of the electric turbine motor is met.

9. The system of claim 8, wherein one or more of the following: The engine speed condition is satisfied if the engine speed does not exceed the engine speed threshold; The turbine speed condition is met if the estimated turbine speed of the lower pressure turbocharger does not exceed the turbine speed threshold; If the air-fuel ratio of the internal combustion engine does not exceed the AFR threshold, the AFR condition is met; If the internal combustion engine is operating in an oxygen-fuel control mode, the OFC condition is met; and The minimum off-time condition for the electric turbine motor is met if the electric turbine motor has been off or deactivated for at least a predetermined time.

10. The system according to claim 8, wherein: The electronic control system is configured to terminate operation of the electric turbine motor in any of the following situations: The engine speed condition is not met; Turbine speed conditions are not met; does not meet the AFR conditions; and The maximum on-time condition of the electric turbine motor is met.

11. The system according to claim 10, wherein: The maximum on-time condition of the electric turbine motor is met if the electric turbine motor has been on or activated for at least a predetermined time.

12. An apparatus for controlling the operation of an internal combustion engine, the internal combustion engine comprising: Intake and exhaust systems; at least one cylinder for receiving an intake flow from an intake system, for receiving fuel and for generating an exhaust flow to an exhaust system; a valve train associated with at least one cylinder, the valve train including at least one intake valve for operation in a Miller cycle, and at least one exhaust valve; a multi-stage turbocharger system driven by exhaust gas flow, the multi-stage turbocharger system comprising a first compressor in an intake system, the first compressor coupled to an electric turbo motor and coupled to a first turbine, the multi-stage turbocharger further comprising a second compressor downstream of the first compressor and a second turbine coupled to the second compressor upstream of the first turbine; The apparatus comprises a controller operably connected to an internal combustion engine, the controller being configured to: Identify transient events associated with the internal combustion engine, and Operation of the electric turbine motor is initiated in response to the transient event to provide compression boost of the intake air flow via the first compressor.

13. The device according to claim 12, wherein: The controller is configured to receive input from one or more sensors providing one or more parameters indicative of an engine speed of the internal combustion engine, turbine speeds associated with the first compressor and the first turbine, air-fuel ratio (AFR) conditions, and oxygen-fuel control (OFC) conditions.

14. The device according to claim 13, wherein: The controller is configured to operate the electric turbine motor to drive the first compressor in response to the transient condition when: In response to the engine speed not exceeding an engine speed threshold, an engine speed condition is satisfied; In response to the turbine speed not exceeding the turbine speed threshold, a turbine speed condition is satisfied; an air-fuel ratio (AFR) condition does not exceed an AFR threshold or an oxygen-fuel control (OFC) condition operates in an oxygen-fuel control mode; and The minimum off-time condition of the electric turbine motor is satisfied by the electric turbine motor being off or deactivated for at least a predetermined time.

15. The device according to claim 14, wherein: The electronic control system is configured to terminate operation of the electric turbine motor in any of the following situations: The engine speed condition is not met; Turbine speed conditions are not met; does not meet the AFR conditions; and The maximum on-time condition of the electric turbine motor is met.

16. A method comprising: Valve trains of internal combustion engines operating on the Miller cycle; detecting transient events during operation of the valve train in a Miller cycle; In response to the transient event, initiating operation of the electric turbo motor to boost compression of intake air flow from a first stage of the multi-stage turbocharger system to a second stage of the multi-stage turbocharger system; as well as The boost compressed intake air flow from the first stage is further compressed by means of a second stage of the multi-stage turbocharger system upstream of the internal combustion engine.

17. The method of claim 16, further comprising initiating operation of the electric turbine motor to boost compression of the intake air flow in response to a transient event only when: In response to the engine speed not exceeding an engine speed threshold, an engine speed condition is satisfied; In response to a turbine speed of the first stage not exceeding a turbine speed threshold, a turbine speed condition is satisfied; an air-fuel ratio (AFR) condition not exceeding an AFR threshold or an oxygen-fuel control (OFC) condition operating in an oxygen-fuel control mode; and The minimum off-time condition of the electric turbine motor is satisfied by the electric turbine motor being off or deactivated for at least a predetermined time.

18. The method of claim 17, further comprising terminating operation of the electric turbine motor in any of the following situations: The engine speed condition is not met; Turbine speed conditions are not met; does not meet the AFR conditions; and The maximum on-time condition of the electric turbine motor is met.

19. The method of claim 16, further comprising engaging an electric turbine motor to a shaft between a compressor and a turbine of a first stage of a multi-stage turbocharger in response to a transient event.

20. The method of claim 16, further comprising: Intercooling the boost compressed intake air flow between the first and second stages of a multi-stage turbocharger system; as well as The further compressed intake air flow is aftercooled downstream of the second stage of the multi-stage turbocharger system.

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