# US 2018/0321105 A1 · Dual fuel combustion intensity > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0321105 A1 - Document ID: US20180321105A1 - Status: Published application - Kind: A1 - Application number: 15/971,957 - Filed: 2018-05-04 - Published: 2018-11-08 - Earliest claimed: 2017-05-05 - Assignees: Woodward, Inc. - Applicants: Woodward, Inc. - Inventors: Jason Barta; Gregory James Hampson; Suraj Nair; Jeffrey Carlson - Web page: https://patentgrep.com/patent/US20180321105A1 ## CPC - G01L 23/222: {using piezoelectric devices} - F02B 77/085: {with sensors measuring combustion processes, e.g. knocking, pressure, ionization, combustion flame} - F02D 19/0623: {Failure diagnosis or prevention; Safety measures; Testing} - F02D 19/081: {Adjusting the fuel composition or mixing ratio; Transitioning from one fuel to the other} - F02D 19/10: peculiar to compression-ignition engines in which the main fuel is gaseous - F02D 35/023: {by determining the cylinder pressure} - F02D 35/028: {by determining the combustion timing or phasing} - F02D 41/0025: {Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures} - F02D 41/0027: {the fuel being gaseous (non-electrical control F02D19/02)} - 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)} - F02D 41/3047: {said means being a secondary injection of fuel} - G01L 23/22: for detecting or indicating knocks in internal-combustion engines; Units comprising pressure-sensitive members combined with ignitors for firing internal-combustion engines - G01M 15/11: by detecting misfire - F02D 19/0647: {the gaseous fuel being liquefied petroleum gas [LPG], liquefied natural gas [LNG], compressed natural gas [CNG] or dimethyl ether [DME]} - F02D 2200/0404: Throttle position - F02D 2200/0614: Actual fuel mass or fuel injection amount - Y02T 10/30: Use of alternative fuels, e.g. biofuels - G01L: MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE (weighing G01G) - F02B: INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (gas-turbine plants F02C; hot-gas or combustion-product positive-displacement engine plants F02G) - 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) - G01M: TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A method of detecting uncontrolled combustion in an internal combustion engine includes sampling in-cylinder pressure sensor configured to measure pressure in a cylinder of the engine and generate a pressure signal, calculating a combustion intensity metric based on the pressure signal, determining a parameter describing how close the engine is to an uncontrolled combustion condition based on the combustion intensity metric, and controlling a substitution rate of a first fuel and a second fuel based on one or more of the parameter and the combustion intensity metric. ## Claims ### Claim 1 A method of detecting uncontrolled combustion in an internal combustion engine, comprising: sampling a pressure signal from in-cylinder pressure sensor, the pressure signal representative of a measured pressure in a cylinder of the engine; calculating a combustion intensity metric based on the pressure signal, wherein the combustion intensity metric is an indicator of the engine's proximity to an uncontrolled combustion condition; determining an engine control parameter as a function of the combustion intensity metric; and controlling the engine based on the engine control parameter. ### Claim 2 (depends on 1) The method of claim 1, wherein the internal combustion engine comprises a dual-fuel internal combustion engine and wherein the engine control parameter comprises a substitution rate of a first fuel and a second fuel based on at least one of the parameter or the combustion intensity metric. ### Claim 3 (depends on 2) The method of claim 2, wherein the first fuel is diesel and wherein the second fuel is natural gas. ### Claim 4 (depends on 1) The method of claim 1, wherein the combustion intensity metric is calculated within a same combustion cycle as the sampling of the in-cylinder pressure sensor. ### Claim 5 (depends on 1) The method of claim 1, comprising: calculating, based on the pressure signal, a pressure metric, a heat release metric, and a knock metric, wherein the combustion intensity metric a function of the pressure metric, the heat release metric, and the knock metric. ### Claim 6 (depends on 5) The method of claim 5, wherein the heat release metric comprises an adiabatic heat release rate of combustion in a cylinder of the engine. ### Claim 7 (depends on 1) The method of claim 1, comprising calculating at least one of the following combustion metrics based on the pressure signal: the peak cylinder pressure; the crank angle of peak cylinder pressure; a rate of cylinder pressure rise; a cylinder pressure ripple; the crank angle of a cylinder pressure ripple; a burn duration; a slope of heat release; the crank angle of centroid of heat release; or the crank angle of max heat release rate. ### Claim 8 (depends on 7) The method of claim 7, wherein the combustion intensity metric is a function of at least one of: the peak cylinder pressure; the crank angle of peak cylinder pressure; the rate of cylinder pressure rise; the cylinder pressure ripple; the crank angle of cylinder ripple; the bum duration; the slope of heat release; the crank angel of centroid of heat release; or the crank angle of max heat release rate. ### Claim 9 (depends on 8) The method of claim 8, wherein the combustion intensity metric is a function of at least the peak pressure, the rate of pressure rise, the pressure ripple, the burn duration, and the slope of heat release. ### Claim 10 (depends on 1) The method of claim 1, comprising determining a fuel input signal, a throttle position signal, and an ignition timing signal for the engine based on at least one of the combustion intensity metric or the parameter. ### Claim 11 A controller for controlling operation of a dual-fuel internal combustion engine of an engine system, the engine system comprising a pressure sensor configured to measure pressure in a cylinder of the engine and generate a corresponding pressure signal and a crank angle sensor configured to measure the crank angle of the engine and generate a corresponding crank angle signal, the controller comprising: a processor couplable to the in-pressure sensor and the crank angle sensor; and at least one non-transitory computer readable medium storing instructions operable to cause the processor of the controller to perform operations comprising: (a) sample the pressure signal; (b) calculate a combustion intensity metric based on the pressure signal, wherein the combustion intensity metric is an indicator of the engine's proximity to an uncontrolled combustion condition; (c) determine a substitution rate of a first fuel and a second fuel delivered to the cylinder based on the combustion intensity metric; and (d) control the dual-fuel internal combustion engine based on the substitution rate. ### Claim 12 (depends on 11) The controller of claim 11, wherein first fuel is diesel and wherein the second fuel is natural gas. ### Claim 13 (depends on 11) The controller of claim 11, wherein steps (b) and (c) occur within a next cycle of the cylinder. ### Claim 14 (depends on 11) The controller of claim 11, wherein the instructions include calculating, based on the pressure signal, a pressure metric, a heat release metric, and a knock metric, and wherein the combustion intensity metric a function of the pressure metric, the heat release metric, and the knock metric. ### Claim 15 (depends on 11) The controller of claim 11, wherein calculating the heat release metric comprises calculating an adiabatic heat release rate of combustion in the cylinder of the engine. ### Claim 16 (depends on 11) The controller of claim 11, wherein the instructions include calculating at least one of the following combustion metrics based on the pressure signal: the peak cylinder pressure; the crank angle of peak cylinder pressure; a rate of pressure rise; a pressure ripple; a location of cylinder pressure ripple; a burn duration; a slope of heat release; the crank angle of centroid of heat release; or the crank angle of max heat release rate. ### Claim 17 (depends on 16) The controller of claim 16, wherein the combustion intensity metric is a function of at least one of: the peak cylinder pressure; the crank angle of peak cylinder pressure; the rate of cylinder pressure rise; the cylinder pressure ripple; the crank angle of ripple; the bum duration; the slope of heat release; the crank angle of centroid of heat release; or the crank angle of max heat release rate. ### Claim 18 (depends on 16) The controller of claim 16, wherein the combustion intensity metric is a function of at least the peak pressure, the rate of pressure rise, the pressure ripple, the burn duration, and the slope of heat release. ### Claim 19 (depends on 11) The controller of claim 11, wherein the instructions include: determine at least one of: a fuel input signal, a throttle position signal, or an ignition timing signal for the dual-fuel internal combustion engine based on at least one of the combustion intensity metric or the parameter, and control the dual-fuel internal combustion engine using at least one of: the fuel input signal, the throttle position signal, or the ignition timing signal. ### Claim 20 A controller for controlling operation of an internal combustion engine of an engine system, the engine system comprising a pressure sensor configured to measure pressure in a cylinder of the engine and generate a corresponding pressure signal and a crank angle sensor configured to measure the crank angle of the engine and generate a corresponding crank angle signal, the controller comprising: a processor couplable to the in-pressure sensor and the crank angle sensor; and at least one non-transitory computer readable medium storing instructions operable to cause the processor of the controller to perform operations comprising: (a) sample the pressure signal; (b) calculate a combustion intensity metric based on the pressure signal, wherein the combustion intensity metric is an indicator of the engine's proximity to an uncontrolled combustion condition; (c) determine an engine control parameter as a function of the combustion intensity metric; and (d) control the engine based on the engine control parameter.