# US 11,306,694 B2 · Method for operating an internal combustion engine having at least one combustion chamber and internal combustion engine for carrying out such a method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,306,694 B2 - Document ID: US11306694B2 - Status: Granted - Kind: B2 - Application number: 16/876,182 - Filed: 2020-05-18 - Published: 2020-09-03 - Granted: 2022-04-19 - Earliest claimed: 2017-11-21 - Assignees: Rolls-Royce Solutions GmbH - Applicants: MTU Friedrichshafen GmbH - Inventors: Tobias Frank; Thorsten Konrad; Aron Toth - Web page: https://patentgrep.com/patent/US11306694B2 ## CPC - F02P 5/152: dependent on pinking (detecting or indicating knocks in internal-combustion engines G01L23/22) - F02D 35/027: {using knock sensors} - G01L 23/221: {for detecting or indicating knocks in internal combustion engines} - F02D 35/023: {by determining the cylinder pressure} - 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) - 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) - G01L: MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE (weighing G01G) ## Abstract A method for operating an internal combustion engine. The method includes detecting a structure borne sound signal in a time-dependent manner for the at least one combustion chamber during operation of the internal combustion engine, and determining, in a predetermined measuring window, at least one evaluation parameter from the detected structure borne sound signal. The method also includes obtaining at least one comparative result by comparing the at least one evaluation parameter with at least one predetermined comparison value, and assigning to the structure borne sound signal, on the basis of the at least one comparative result, one of a knocking event in the at least one combustion chamber and an interference signal. ## Claims ### Claim 1 A method for operating an internal combustion engine, the internal combustion engine including at least one combustion chamber, the method comprising: detecting a structure borne sound signal in a time-dependent manner for the at least one combustion chamber during operation of the internal combustion engine; determining, in a predetermined measuring window, at least one evaluation parameter from the detected structure borne sound signal, the at least one evaluation parameter including a temporal length of a signal curve progression, the temporal length, which is irrespective of an output wave of a cylinder internal pressure sensor, being associated with a single sensor for detecting the structure borne sound signal and being calculated as a difference between a second time index value and a first time index value; obtaining at least one comparative result by comparing the at least one evaluation parameter with at least one predetermined comparison value; and assigning to the structure borne sound signal, on the basis of the at least one comparative result, one of a knocking event in the at least one combustion chamber and an interference signal. ### Claim 2 (depends on 1) The method according to claim 1, further comprising a step of implementing at least one knocking prevention measure if the knocking event is assigned to the structure borne sound signal. ### Claim 3 (depends on 1) The method according to claim 1, wherein the internal combustion engine further includes a knock sensor, the knock sensor is configured for detecting the structure borne sound signal. ### Claim 4 (depends on 1) The method according to claim 1, wherein the at least one predetermined comparison value is at least one threshold value. ### Claim 5 (depends on 4) The method according to claim 4, wherein a knocking signal is assigned to the structure borne sound signal if the at least one evaluation parameter is greater than the at least one predetermined comparison value, and wherein an interference signal is assigned to the structure borne sound signal if the at least one evaluation parameter is smaller than the at least one predetermined comparison value. ### Claim 6 (depends on 1) The method according to claim 1, wherein the at least one evaluation parameter includes an energy parameter, which is characteristic for an energy contained in the structure borne sound signal, wherein the energy parameter is determined in that the structure borne sound signal is squared, wherein the squared structure borne sound signal is integrated over the predetermined measuring window. ### Claim 7 (depends on 6) The method according to claim 6, wherein the temporal length of the signal curve progression of the structure borne sound signals is determined in that the structure borne sound signal is squared. ### Claim 8 (depends on 7) The method according to claim 7, wherein the squared structure borne sound signal is standardized with a maximum of the squared structure borne sound signal inside the predetermined measuring window. ### Claim 9 (depends on 8) The method according to claim 8, wherein for the standardized and squared structure borne sound signal the first time index value is determined in the measuring window at a first signal threshold value, and wherein a second time index value is determined at a later stage at the second signal threshold value, the temporal length being longer than a predetermined comparative temporal length value when a knocking event occurs. ### Claim 10 (depends on 1) The method according to claim 1, wherein the at least one evaluation parameter includes a signal shape value of the structure borne sound signal, the signal shape value being associated with a single sensor for detecting the structure borne sound signal, wherein the signal shape value is determined in that the structure borne sound signal is squared, wherein the squared structure borne sound signal is standardized with a maximum of the squared structure borne sound signal inside the predetermined measuring window. ### Claim 11 (depends on 10) The method according to claim 10, wherein the standardized and squared structure borne sound signal is integrated over the predetermined measuring window. ### Claim 12 (depends on 1) The method according to claim 1, wherein the structure borne sound signal is filtered prior to a squaring of the structure borne sound signal. ### Claim 13 An internal combustion engine, comprising: at least one combustion chamber; at least one ignition device connected to the at least one combustion chamber; and a controller operably connected to the at least one ignition device, the controller being configured for: detecting a structure borne sound signal in a time-dependent manner for the at least one combustion chamber during operation of the internal combustion engine; determining, in a predetermined measuring window, at least one evaluation parameter from the detected structure borne sound signal, the at least one evaluation parameter including: a temporal length of a signal curve progression, the temporal length, which is irrespective of an output wave of a cylinder internal pressure sensor, being associated with a single sensor for detecting the structure borne sound signal and being calculated as a difference between a second time index value and a first time index value; obtaining at least one comparative result by comparing the at least one evaluation parameter with at least one predetermined comparison value; and assigning to the structure borne sound signal, on the basis of the at least one comparative result, one of a knocking event in the at least one combustion chamber and an interference signal. ### Claim 14 (depends on 13) The internal combustion engine according to claim 13, wherein the controller is further configured for implementing at least one knocking prevention measure if the knocking event is assigned to the structure borne sound signal. ### Claim 15 (depends on 13) The internal combustion engine according to claim 13, further including a knock sensor operably connected to the controller, the knock sensor is configured for detecting the structure borne sound signal. ### Claim 16 (depends on 13) The internal combustion engine according to claim 13, wherein the at least one predetermined comparison value includes at least one threshold value. ### Claim 17 (depends on 16) The internal combustion engine according to claim 16, wherein a knocking signal is assigned to the structure borne sound signal if the at least one evaluation parameter is greater than the at least one predetermined comparison value, and wherein an interference signal is assigned to the structure borne sound signal, if the at least one evaluation parameter is smaller than the at least one predetermined comparison value. ### Claim 18 (depends on 13) The internal combustion engine according to claim 13, wherein the at least one evaluation parameter includes an energy parameter, which is characteristic for an energy contained in the structure borne sound signal, wherein the energy parameter is determined in that the structure borne sound signal is squared, wherein the squared structure borne sound signal is integrated over the predetermined measuring window.