# US 10,371,075 B2 · Control apparatus for internal combustion engine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,371,075 B2 - Document ID: US10371075B2 - Status: Granted - Kind: B2 - Application number: 15/741,604 - Filed: 2016-07-06 - Published: 2018-07-12 - Granted: 2019-08-06 - Earliest claimed: 2015-07-15 - Assignees: Hitachi Automotive Systems, Ltd. - Applicants: Hitachi Automotive Systems, Ltd. - Inventors: Shinya Matohara; Yoshihiko Akagi; Seiji Asano; Kazuhiro Oryoji - Web page: https://patentgrep.com/patent/US10371075B2 ## CPC - F02D 41/144: {Sensor in intake manifold} - F02D 41/0002: {Controlling intake air} - F02D 41/0042: {Controlling the combustible mixture as a function of the canister purging, e.g. control of injected fuel to compensate for deviation of air fuel ratio when purging} - F02D 41/0045: {Estimating, calculating or determining the purging rate, amount, flow or concentration} - F02D 41/0072: {Estimating, calculating or determining the EGR rate, amount or flow (sensors in EGR systems F02M26/45)} - 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)} - F02D 41/04: Introducing corrections for particular operating conditions (F02D41/14 takes precedence) - F02D 41/14: Introducing closed-loop corrections - F02D 43/00: Conjoint electrical control of two or more functions, e.g. ignition, fuel-air mixture, recirculation, supercharging or exhaust-gas treatment - F02D 45/00: Electrical control not provided for in groups F02D41/00 - F02D43/00 - F02M 25/08: adding fuel vapours drawn from engine fuel reservoir {(electrical control of purge system F02D41/003)} - F02M 25/089: {Layout of the fuel vapour installation} - F02M 26/17: in relation to the intake system - F02M 26/46: for determining the characteristics of gases, e.g. composition - F02P 5/045: {combined with electronic control of other engine functions, e.g. fuel injection (in general F02D37/02)} - F02P 5/15: Digital data processing - F02P 5/1516: {with means relating to exhaust gas recirculation, e.g. turbo} - F02D 2200/0414: Air temperature - F02D 2200/0418: Air humidity - 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) - 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) ## Abstract An EGR rate estimation method using an EGR valve opening area involves aggravated EGR rate estimation accuracy as an EGR valve is deteriorated and is unable to satisfy required accuracy when a target EGR rate is high. With a method for correcting a fuel injection amount by a fuel injection valve through estimation of a purge air-fuel ratio on the basis of variations in an air-fuel ratio variable depending on whether purging is performed, the fuel injection correction fails to accommodate the change in the air-fuel ratio when concentration of fuel evaporative emissions adsorbed by an activated carbon of a canister is high, resulting in reduced conversion efficiency of a catalyst. An arrangement includes an introduction port that is disposed in an intake pipe and through which a gas other than fresh air flows in the intake pipe and humidity sensors disposed upstream and downstream, respectively, of the introduction port. The EGR rate or the purge air-fuel ratio in the intake pipe is estimated using detection values of the respective humidity sensors. ## Claims ### Claim 1 A control apparatus for an internal combustion engine, the control apparatus controlling the internal combustion engine including an intake pipe and a throttle valve disposed in the intake pipe, the throttle valve controlling an air flow rate, the control apparatus comprising: an introduction port that is disposed in the intake pipe and through which a gas other than fresh air flows in the intake pipe, wherein the control apparatus controls the internal combustion engine using detection values of humidity sensors disposed upstream and downstream, respectively, of the introduction port, a purge system disposed in the intake pipe, the purge system including: a canister that adsorbs fuel evaporative emissions to thereby allow the internal combustion engine to draw air while diluting the fuel evaporative emissions with atmosphere; and a purge flow rate estimation unit that introduces a purge gas as the gas other than fresh air, wherein the purge gas is connected to a connection with the intake pipe via a purge introduction pipe, and the internal combustion engine is controlled using the detection values of the humidity sensors disposed upstream and downstream, respectively, of the connection, and wherein a purge air-fuel ratio as a ratio of air to the fuel evaporative emissions contained in the purge gas at a position downstream of the connection is obtained using the detection values of the respective humidity sensors. ### Claim 2 (depends on 1) The control apparatus for an internal combustion engine according to claim 1, comprising: a return pipe disposed in the intake pipe, the return pipe returning part of an exhaust gas and introducing an EGR gas as the gas other than fresh air, wherein the control apparatus controls the internal combustion engine using the detection values of the humidity sensors disposed upstream and downstream, respectively, of a connection between the intake pipe and the return pipe. ### Claim 3 (depends on 2) The control apparatus for an internal combustion engine according to claim 2, wherein an EGR rate that represents a ratio of intake air flowing through the intake pipe and the EGR gas returned through the return pipe is estimated using the detection values of the respective humidity sensors. ### Claim 4 (depends on 3) The control apparatus for an internal combustion engine according to claim 3, wherein the EGR rate in the intake pipe is estimated using volume fractions of water vapor upstream and downstream, respectively, of the connection of the intake pipe and a volume fraction of water vapor in the exhaust gas. ### Claim 5 (depends on 4) The control apparatus for an internal combustion engine according to claim 4, wherein the volume fraction of water vapor that increases through combustion in the exhaust gas is calculated on the basis of a ratio of carbon to hydrogen in fuel. ### Claim 6 (depends on 5) The control apparatus for an internal combustion engine according to claim 5, comprising: a fuel property determination unit, wherein the ratio of carbon to hydrogen in fuel is determined on the basis of a fuel property determination result. ### Claim 7 (depends on 4) The control apparatus for an internal combustion engine according to claim 4, wherein, when the EGR rate in the intake pipe is higher than a target EGR rate, ignition timing is advanced. ### Claim 8 (depends on 4) The control apparatus for an internal combustion engine according to claim 4, wherein, when the EGR rate in the intake pipe is higher than a target EGR rate, an EGR valve opening is controlled to be brought on a closing side with respect to a current opening. ### Claim 9 (depends on 4) The control apparatus for an internal combustion engine according to claim 4, wherein, when the EGR rate in the intake pipe is lower than a target EGR rate, ignition timing is retarded. ### Claim 10 (depends on 4) The control apparatus for an internal combustion engine according to claim 4, wherein, when the EGR rate in the intake pipe is lower than a target EGR rate, an EGR valve opening is controlled to be brought on an opening side with respect to a current opening. ### Claim 11 (depends on 1) The control apparatus for an internal combustion engine according to claim 1, wherein the purge air-fuel ratio as the ratio of air to the fuel evaporative emissions contained in the purge gas at a position downstream of the connection is obtained using relative humidity upstream and downstream, respectively, of the connection. ### Claim 12 (depends on 1) The control apparatus for an internal combustion engine according to claim 1, wherein the purge air-fuel ratio as the ratio of air to the fuel evaporative emissions contained in the purge gas at a position downstream of the connection is obtained using absolute humidity upstream and downstream, respectively, of the connection. ### Claim 13 (depends on 11) The control apparatus for an internal combustion engine according to claim 11, wherein a fuel injection amount at a fuel injection valve is corrected on the basis of an estimated result of the purge air-fuel ratio.