# US 11,028,792 B2 · Systems and methods for controlling EGR flow during transient conditions > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,028,792 B2 - Document ID: US11028792B2 - Status: Granted - Kind: B2 - Application number: 16/241,443 - Filed: 2019-01-07 - Published: 2019-08-15 - Granted: 2021-06-08 - Earliest claimed: 2013-11-04 - Assignees: Cummins Inc. - Applicants: Cummins Inc. - Inventors: Carlos Alcides Lana; David J. Stroh; Samuel C. Geckler; Marten H. Dane; Anthony Kyle Perfetto; Karthik Kappaganthu; Govindarajan Kothandaraman - Web page: https://patentgrep.com/patent/US11028792B2 ## CPC - F02D 41/0077: {Control of the EGR valve or actuator, e.g. duty cycle, closed loop control of position (EGR valve position sensor F02M26/48)} - F02B 37/18: by bypassing exhaust {from the inlet to the outlet of turbine or to the atmosphere} - F02B 37/24: by using pumps or turbines with adjustable guide vanes - F02D 13/02: during engine operation - F02D 13/0261: {Controlling the valve overlap} - F02D 41/0007: {for control of turbo-charged or super-charged engines (control of the pumps per se F02B37/12)} - F02D 41/0072: {Estimating, calculating or determining the EGR rate, amount or flow (sensors in EGR systems F02M26/45)} - F02D 41/008: {Controlling each cylinder individually} - F02M 26/05: High pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust system upstream of the turbine and reintroduced into the intake system downstream of the compressor - F02M 26/06: Low pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust downstream of the turbocharger turbine and reintroduced into the intake system upstream of the compressor - F02M 26/13: Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories - F02M 26/37: with temporary storage of recirculated exhaust gas (internal exhaust gas recirculation F02M26/01) - F02M 26/43: in which exhaust from only one cylinder or only a group of cylinders is directed to the intake of the engine - F02P 5/1512: {with particular means concerning an individual cylinder} - F02P 5/1516: {with means relating to exhaust gas recirculation, e.g. turbo} - F02D 2021/083: {controlling exhaust gas recirculation electronically} - F02D 2041/001: {for engines with variable valve actuation} - Y02T 10/12: Improving ICE efficiencies - Y02T 10/40: Engine management systems - F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W) - F02B: INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (gas-turbine plants F02C; hot-gas or combustion-product positive-displacement engine plants F02G) - F02M: SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF - F02P: IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES ({anti-pollution means for internal-combustion engines F02B17/00}; specially adapted for rotary-piston or oscillating-piston engines F02B53/12; {ignition of gas turbine plants F02C7/26; ignition of jet propulsion plants F02K9/95; starting of combustion engines F02N9/00}; ignition of combustion apparatus in general, glowing plugs F23Q; measuring of physical variables in general G01; controlling in general G05; data processing in general G06; electrical components in general see Section H; {ignition coils H01F38/12}; sparking plugs H01T13/00) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract Systems, apparatus, and methods are disclosed that include a divided exhaust engine with at least one primary EGR cylinder and a plurality of non-primary EGR cylinders. The systems, apparatus and methods control the amount of recirculated exhaust gas in a charge flow in response to EGR fraction deviation conditions. ## Claims ### Claim 1 A system comprising: an internal combustion engine having at least one primary exhaust gas recirculation (EGR) cylinder connected to provide an EGR flow to an EGR passage and a plurality of non-primary cylinders connected to provide an exhaust flow to an exhaust passage; wherein the EGR passage is connected to an intake system to provide an EGR flow from the at least one primary EGR cylinder to the intake system, the EGR passage being one of flow isolated and flow isolatable from the exhaust passage; the internal combustion engine having a low pressure EGR loop that connects the exhaust passage to the intake system; wherein the intake system provides a charge flow to the at least one primary EGR cylinder and the plurality of non-primary cylinders, the charge flow including an intake air flow and an EGR fraction provided by an amount of recirculated exhaust gas from at least the at least one primary EGR cylinder; and a controller operably connected to the internal combustion engine, the controller including a non-transitory computer readable medium with executable instructions: during a transient operating condition of the internal combustion engine, to determine an EGR fraction deviation condition in which the EGR fraction provided by the amount of recirculated exhaust gas in the charge flow deviates from an expected EGR fraction; and to adjust the amount of recirculated exhaust gas to the intake system toward the expected EGR fraction in response to the EGR fraction deviation condition via actuation of an EGR control valve in the low pressure EGR loop to adjust the amount of recirculated exhaust gas toward the expected EGR fraction by selectively providing a portion of the exhaust flow from the exhaust passage to the intake system through the low pressure EGR loop and simultaneously providing a portion of EGR flow from the at least one primary EGR cylinder to the intake system. ### Claim 2 (depends on 1) The system of claim 1, wherein: the intake system includes a compressor in an intake passage that is connected to a turbine in the exhaust passage operable to drive the compressor with the exhaust flow from the plurality of non-primary EGR cylinders; and the EGR passage is connected to the intake passage downstream of the compressor. ### Claim 3 (depends on 2) The system of claim 2, wherein the EGR passage is flow isolated from the exhaust passage and further comprising a compressor EGR passage connecting the EGR passage to the intake system upstream of the compressor. ### Claim 4 (depends on 3) The system of claim 3, wherein the controller further comprises executable instructions to actuate a control valve in the compressor EGR passage to selectively adjust the amount of recirculated exhaust gas toward the expected EGR fraction by selectively providing a portion of the EGR flow from the EGR passage to the intake system through the compressor EGR passage. ### Claim 5 (depends on 1) The system of claim 1, wherein the intake system includes a compressor connected to a turbine in the exhaust passage and the turbine is operable to drive the compressor with the exhaust flow in the exhaust passage, and further comprising: the low pressure EGR passage connecting the EGR passage to the exhaust passage downstream of the turbine. ### Claim 6 (depends on 1) The system of claim 1, further comprising: an EGR cooler in the low pressure EGR loop that is positioned upstream of the control valve. ### Claim 7 (depends on 1) The system of claim 1, wherein the at least one primary EGR cylinder includes a single primary EGR cylinder that provides the EGR flow. ### Claim 8 (depends on 1) The system of claim 1, further comprising a high pressure EGR passage connecting the EGR passage to the exhaust passage and a control valve in the high pressure EGR passage, wherein the controller is configured to adjust the amount of recirculated exhaust gas toward the expected EGR fraction by actuating the control valve to selectively provide one of a portion of the exhaust flow from the exhaust passage to the EGR passage and a portion of the EGR flow from the EGR passage to the exhaust passage. ### Claim 9 (depends on 8) The system of claim 8, wherein the intake system includes a compressor that is connected to a turbine in the exhaust passage and the turbine is operable to drive the compressor with the exhaust flow in the exhaust passage, and the high pressure EGR passage is connected to the exhaust passage upstream of the turbine. ### Claim 10 A method of controlling a charge flow to an internal combustion engine having at least one primary exhaust gas recirculation (EGR) cylinder connected to an EGR passage and a plurality of non-primary EGR cylinders connected to an exhaust passage, comprising: supplying an exhaust flow from the non-primary EGR cylinders through the exhaust passage, wherein the exhaust passage is connected to a low pressure EGR loop that connects the exhaust passage to an intake system; supplying an EGR flow from the at least one primary EGR cylinder through the EGR passage to the intake system, the charge flow including an EGR fraction corresponding to an amount of recirculated exhaust gas in the charge flow from at least the at least one primary EGR cylinder; during a transient operating condition of the internal combustion engine, determining, with a controller, an EGR fraction deviation condition in the charge flow to the internal combustion engine in response to a deviation of the EGR fraction from an expected EGR fraction via adjusting an EGR control valve in the low pressure EGR loop to adjust the amount of recirculated exhaust gas provided to the intake system; and adjusting, with the controller, the amount of recirculated exhaust gas provided to the intake system to mitigate or reduce the deviation of the EGR fraction from the expected EGR fraction in response to determining the EGR fraction deviation condition. ### Claim 11 (depends on 10) The method of claim 10, further comprising compressing the intake flow with a compressor in an intake passage of the intake system; wherein the compressor is connected to a turbine in the exhaust passage that drives the compressor with the exhaust flow from the plurality of non-primary EGR cylinders. ### Claim 12 (depends on 11) The method of claim 11, wherein: the EGR passage is flow isolated from the exhaust passage and connected to the intake system downstream of the compressor; and adjusting the recirculated amount of exhaust gas includes selectively providing a portion of the exhaust flow from the exhaust passage into the intake passage through the low pressure EGR loop connecting the exhaust passage to the intake passage downstream of the turbine and upstream of the compressor. ### Claim 13 (depends on 11) The method of claim 11, wherein: the EGR passage is flow isolated from the exhaust passage and connected to the intake system downstream of the compressor; and adjusting the recirculated amount of exhaust gas includes selectively providing a portion of the EGR flow to the intake system through a compressor EGR passage that is connected to the intake system upstream of the compressor. ### Claim 14 (depends on 11) The method of claim 11, wherein adjusting the recirculated amount of exhaust gas includes selectively providing a portion of the EGR flow from the EGR passage to the exhaust passage through a low pressure EGR passage connecting the EGR passage to the exhaust passage downstream of the turbine. ### Claim 15 (depends on 14) The method of claim 14, wherein determining, with the controller, the EGR fraction deviation condition includes detecting a change in an engine operating condition during the transient operating condition of the internal combustion engine. ### Claim 16 (depends on 15) The method of claim 15, wherein the engine operating condition includes at least one of a change in engine speed, a change in engine torque output, a torque request change, an intake manifold pressure change, an intake manifold temperature change, an exhaust manifold pressure change, and an exhaust manifold temperature change. ### Claim 17 (depends on 10) The method of claim 10, further comprising: during a steady state low load operating condition of the internal combustion engine, determining, with the controller, the EGR fraction deviation condition. ### Claim 18 (depends on 10) The method of claim 10, wherein determining the EGR fraction deviation condition includes detecting one of an accelerator tip-in condition and an accelerator tip-out condition.