# US 11,898,477 B2 · Controller and control method 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 11,898,477 B2 - Document ID: US11898477B2 - Status: Granted - Kind: B2 - Application number: 18/329,708 - Filed: 2023-06-06 - Published: 2023-12-14 - Granted: 2024-02-13 - Earliest claimed: 2022-06-10 - Assignees: Toyota Jidosha Kabushiki Kaisha - Applicants: Toyota Jidosha Kabushiki Kaisha - Inventors: Toru Yaeo; Yoshifumi Matsuda; Masashi Hakariya; Atsushi Morikawa; Ikuo Hoda; Noriyasu Adachi; Masanori Hayashi; Kenji Igawa - Web page: https://patentgrep.com/patent/US11898477B2 ## CPC - F01N 11/005: {the temperature or pressure being estimated, e.g. by means of a theoretical model} - F01N 3/101: {Three-way catalysts} - F01N 11/002: {the diagnostic devices measuring or estimating temperature or pressure in, or downstream of the exhaust apparatus} - F02D 41/0235: {in relation with the state of the exhaust gas treating apparatus (control of exhaust gas treating apparatus per se F01N)} - F02D 41/123: {the fuel injection being cut-off} - F02D 41/1446: {the characteristics being exhaust temperatures} - F02D 41/22: Safety or indicating devices for abnormal conditions {(in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809)} - F01N 2560/025: for measuring or detecting O2, e.g. lambda sensors - F01N 2560/06: the means being a temperature sensor - F01N 2900/0416: using the state of a sensor, e.g. of an exhaust gas sensor - F01N 2900/08: said parameters being related to the engine - F01N 2900/1404: Exhaust gas temperature - F01N 2900/1602: Temperature of exhaust gas apparatus - F02D 2200/0812: Particle filter loading - F02D 2200/1002: Output torque - F02D 2200/101: Engine speed - Y02T 10/40: Engine management systems - F01N: GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES (arrangements in connection with gas exhaust of propulsion units in vehicles B60K13/00; combustion-air intake silencers specially adapted for, or arranged on, internal-combustion engines F02M35/00; protecting against, or damping, noise in general G10K11/16) - 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) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A controller for an internal combustion engine is configured to execute a determination process and an anomaly diagnosing process. The determination process is a process of determining that a deviation between a first change amount and a second change amount during a fuel cutoff operation is less than or equal to a threshold. The anomaly diagnosing process is a process of determining that an exhaust purification device is in a detached state when it is determined in the determination process that the deviation is less than or equal to the threshold. The first change amount and the second change amount are change amounts per unit time of the temperature of exhaust gas on the upstream side and the downstream side of the exhaust purification device, respectively. ## Claims ### Claim 1 A controller for an internal combustion engine, wherein an exhaust purification device is disposed in an exhaust passage of the internal combustion engine, the internal combustion engine is configured to execute a fuel cutoff operation in which an engine output shaft is rotated with fuel supply stopped, the controller comprises processing circuitry, the processing circuitry is configured to execute a first change amount calculating process, a second change amount calculating process, a determination process, and an anomaly diagnosing process, the first change amount calculating process is a process of calculating a first change amount that is a change amount per unit time of an upstream-side temperature, the upstream-side temperature being a temperature of exhaust gas on an upstream side of the exhaust purification device, the second change amount calculating process is a process of calculating a second change amount that is a change amount per unit time of a downstream-side temperature, the downstream-side temperature being a temperature of exhaust gas on a downstream side of the exhaust purification device, the determination process is a process of determining that a deviation between the first change amount during the fuel cutoff operation and the second change amount during the fuel cutoff operation is less than or equal to a threshold, and the anomaly diagnosing process is a process of determining that the exhaust purification device is in a detached state when it is determined in the determination process that the deviation is less than or equal to the threshold. ### Claim 2 (depends on 1) The controller for the internal combustion engine according to claim 1, wherein the determination process includes determining that the deviation between the first change amount during the fuel cutoff operation and the second change amount during the fuel cutoff operation is less than or equal to the threshold, based on an average value of a deviation obtained by subtracting the first change amount from the second change amount in a determination period being less than or equal to a specified value, and the determination period is a period from when the determination process is started to when the upstream-side temperature decreases by a specified temperature from a value at the start of the determination process. ### Claim 3 (depends on 1) The controller for the internal combustion engine according to claim 1, wherein the processing circuitry is configured to start the determination process on condition that the upstream-side temperature exhibits an increasing tendency. ### Claim 4 (depends on 3) The controller for the internal combustion engine according to claim 3, wherein the processing circuitry is configured to execute a first average value calculating process and a second average value calculating process, the first average value calculating process is a process of calculating a short-term moving average value of the upstream-side temperature, the second average value calculating process is a process of calculating a long-term moving average value, the long-term moving average value being a moving average value of the upstream-side temperature in a period longer than a period in which the short-term moving average value is calculated, and the processing circuitry is configured to determine that the upstream-side temperature exhibits an increasing tendency based on a differential value of the short-term moving average value and a differential value of the long-term moving average value both being greater than or equal to a specified value. ### Claim 5 (depends on 1) The controller for the internal combustion engine according to claim 1, wherein the processing circuitry is configured to execute a front-end temperature estimating process and a rear-end temperature estimating process, the front-end temperature estimating process is a process of estimating a front-side temperature, the front-side temperature being a temperature of a section of the exhaust purification device between a center and a front end, the rear-end temperature estimating process is a process of estimating a rear-side temperature, the rear-side temperature being a temperature of a section of the exhaust purification device between the center and a rear end, and the processing circuitry is configured to start the determination process on condition that the front-end temperature is higher than or equal to the rear-end temperature. ### Claim 6 (depends on 1) The controller for the internal combustion engine according to claim 1, wherein the processing circuitry is configured to start the determination process on condition that an air-fuel ratio detected by a sensor disposed upstream of the exhaust purification device in the exhaust passage is within a specified range. ### Claim 7 A control method for an internal combustion engine, wherein an exhaust purification device is disposed in an exhaust passage of the internal combustion engine, the internal combustion engine is configured to execute a fuel cutoff operation in which an engine output shaft is rotated with fuel supply stopped, the control method comprises: calculating a first change amount that is a change amount per unit time of an upstream-side temperature, the upstream-side temperature being a temperature of exhaust gas on an upstream side of the exhaust purification device; calculating a second change amount that is a change amount per unit time of a downstream-side temperature, the downstream-side temperature being a temperature of exhaust gas on a downstream side of the exhaust purification device; determining that a deviation between the first change amount during the fuel cutoff operation and the second change amount during the fuel cutoff operation is less than or equal to a threshold; and determining that the exhaust purification device is in a detached state when it is determined that the deviation is less than or equal to the threshold.