# US 11,078,856 B2 · Wiebe function parameter identification method and information processing device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,078,856 B2 - Document ID: US11078856B2 - Status: Granted - Kind: B2 - Application number: 15/981,029 - Filed: 2018-05-16 - Published: 2018-11-01 - Granted: 2021-08-03 - Earliest claimed: 2015-11-24 - Assignees: Fujitsu Limited - Applicants: Fujitsu Limited - Inventors: Noriyasu Aso; Masatoshi Ogawa - Web page: https://patentgrep.com/patent/US11078856B2 ## CPC - F02D 41/1401: {characterised by the control or regulation method (F02D41/1473, F02D41/1477 take precedence)} - F02D 35/023: {by determining the cylinder pressure} - F02D 35/028: {by determining the combustion timing or phasing} - F02D 41/009: {using means for generating position or synchronisation signals} - F02D 41/1402: {Adaptive control} - F02D 41/1406: {with use of a optimisation method, e.g. iteration} - F02D 41/26: using computer, e.g. microprocessor - F02D 41/402: {Multiple injections} - G06F 17/17: Function evaluation by approximation methods, e.g. inter- or extrapolation, smoothing, least mean square method ({G06F17/18 takes precedence } ; interpolation for numerical control G05B19/18) - F02D 41/1454: {the characteristics being an oxygen content or concentration or the air-fuel ratio} - F02D 2041/1433: {using a model or simulation of the system} - F02D 2200/0602: Fuel pressure - F02D 2200/0614: Actual fuel mass or fuel injection amount - F02D 2200/1004: Estimation of the output torque - F02D 2250/14: Timing of measurement, e.g. synchronisation of measurements to the engine cycle - 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) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A Wiebe function parameter identification method, the method includes: acquiring, by a computer, operation data when an internal-combustion engine is in operation; and identifying values of a plurality of parameters included in a combination of at least two Wiebe functions including a first Wiebe function and a second Wiebe function based on the operation data and a first difference between values of a same parameter of the first Wiebe function and the second Wiebe function. ## Claims ### Claim 1 A Wiebe function parameter identification method, the method comprising: acquiring, by a computer, operation data when an internal-combustion engine is in operation; identifying values of a plurality of parameters included in a combination of at least two Wiebe functions including a first Wiebe function and a second Wiebe function based on the operation data and a first difference between values of a same parameter of the first Wiebe function and the second Wiebe function; and controlling the internal-combustion engine based on the values of the parameters identified by: calculating current rate of heat release based on the value of each model parameter identified; calculating current in-cylinder pressure based on the calculated value of the current rate of heat release; calculating a generated torque of the engine based on the calculated value of the in-cylinder pressure; calculating a control target value of the engine to achieve a drive torque requested by the driver, based on the calculated value of the generated torque of the engine; wherein the driver requests the drive torque according to a vehicle speed and an accelerator opening, or for supporting the operation of the vehicle; and controlling the internal-combustion engine based on the calculated control target value of the engine. ### Claim 2 (depends on 1) The Wiebe function parameter identification method according to claim 1, wherein the identifying the values of the plurality of parameters includes the identifying the values of the plurality of parameters by optimization calculation using an evaluation expression, and the evaluation expression includes a first term which becomes closer to an optimal solution as the first difference increases. ### Claim 3 (depends on 2) The Wiebe function parameter identification method according to claim 2, wherein the evaluation expression further includes a second term which becomes closer to an optimal solution as a second difference between a calculated value of a rate of heat release based on the operation data, and a calculated value of a rate of heat release based on the combination of at least two Wiebe functions decreases. ### Claim 4 (depends on 3) The Wiebe function parameter identification method according to claim 3, wherein the evaluation expression includes a weighting coefficient for each of the first term and the second term. ### Claim 5 (depends on 3) The Wiebe function parameter identification method according to claim 3, wherein the second term is a term of a sum of a square of the second difference obtained for each of a plurality of crank angles. ### Claim 6 (depends on 2) The Wiebe function parameter identification method according to claim 2, wherein the first term is a term of minus of a square of the first difference. ### Claim 7 (depends on 1) The Wiebe function parameter identification method according to claim 1, wherein the plurality of parameters include shape indexes, combustion start times, and combustion periods included in the first Wiebe function and the second Wiebe function, and the first difference includes at least one of a difference between the shape indexes and a difference between the combustion periods. ### Claim 8 (depends on 1) The Wiebe function parameter identification method according to claim 1, wherein the identifying the values of the plurality of parameters includes the identifying the values of the plurality of parameters for each of operating conditions, and a relational expression between a plurality of operating condition parameters indicating the operating conditions and the values of the plurality of parameters are derived based on the values of the plurality of parameters identified for each of the operating conditions. ### Claim 9 (depends on 8) The Wiebe function parameter identification method according to claim 8, wherein the relational expression is a first degree polynomial. ### Claim 10 (depends on 1) The Wiebe function parameter identification method according to claim 1, wherein the first Wiebe function and the second Wiebe function model respective two combustion configurations which exhibit as continuous phenomena in a cylinder of the internal-combustion engine. ### Claim 11 (depends on 10) The Wiebe function parameter identification method according to claim 10, wherein the two combustion configurations are each a combustion configuration during after-combustion in a cylinder of a diesel engine. ### Claim 12 An information processing device, comprising: a memory; and a processor coupled to the memory and configured to perform a process, the process includes; acquiring operation data when an internal-combustion engine is in operation; and identifying values of a plurality of parameters included in a combination of at least two Wiebe functions including a first Wiebe function and a second Wiebe function based on the operation data and a first difference between values of a same parameter of the first Wiebe function and the second Wiebe function; and controlling the internal-combustion engine based on the values of the parameters identified by: calculating current rate of heat release based on the value of each model parameter identified; calculating current in-cylinder pressure based on the calculated value of the current rate of heat release; calculating a generated torque of the engine based on the calculated value of the in-cylinder pressure; calculating a control target value of the engine to achieve a drive torque requested by the driver, based on the calculated value of the generated torque of the engine; wherein the driver requests the drive torque according to a vehicle speed and an accelerator opening, or for supporting the operation of the vehicle; and controlling the internal-combustion engine based on the calculated control target value of the engine. ### Claim 13 (depends on 12) The information processing device according to claim 12, wherein the identifying the values of the plurality of parameters includes the identifying the values of the plurality of parameters by optimization calculation using an evaluation expression, and the evaluation expression includes a first term which becomes closer to an optimal solution as the first difference increases. ### Claim 14 (depends on 13) The information processing device according to claim 13, wherein the evaluation expression further includes a second term which becomes closer to an optimal solution as a second difference between a calculated value of a rate of heat release based on the operation data, and a calculated value of a rate of heat release based on the combination of at least two Wiebe functions decreases. ### Claim 15 (depends on 14) The information processing device according to claim 14, wherein the evaluation expression includes a weighting coefficient for each of the first term and the second term. ### Claim 16 (depends on 12) The information processing device according to claim 12, wherein the plurality of parameters include shape indexes, combustion start times, and combustion periods included in the first Wiebe function and the second Wiebe function, and the first difference includes at least one of a difference between the shape indexes and a difference between the combustion periods. ### Claim 17 (depends on 12) The information processing device according to claim 12, wherein the identifying the values of the plurality of parameters includes the identifying the values of the plurality of parameters for each of operating conditions, and a relational expression between a plurality of operating condition parameters indicating the operating conditions and the values of the plurality of parameters are derived based on the values of the plurality of parameters identified for each of the operating conditions. ### Claim 18 (depends on 17) The information processing device according to claim 17, wherein the relational expression is a first degree polynomial. ### Claim 19 (depends on 12) The information processing device according to claim 12, wherein the first Wiebe function and the second Wiebe function model respective two combustion configurations which exhibit as continuous phenomena in a cylinder of the internal-combustion engine. ### Claim 20 (depends on 19) The information processing device according to claim 19, wherein the two combustion configurations are each a combustion configuration during after-combustion in a cylinder of a diesel engine.