# US 2023/0068752 A1 · A method for automatically detecting clogging of a sensor pipe extending between a pressure sensor and an exhaust manifold of an 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 2023/0068752 A1 - Document ID: US20230068752A1 - Status: Published application - Kind: A1 - Application number: 17/793,703 - Filed: 2020-02-18 - Published: 2023-03-02 - Earliest claimed: 2020-02-18 - Assignees: Volvo Truck Corporation - Applicants: Volvo Truck Corporation - Inventors: José Luis Martinez Gordon; Hervé Queret; Damien Daulon; Franck Chagnot Auclair - Web page: https://patentgrep.com/patent/US20230068752A1 ## CPC - F01N 11/002: {the diagnostic devices measuring or estimating temperature or pressure in, or downstream of the exhaust apparatus} - F01N 13/008: {Mounting or arrangement of exhaust sensors in or on exhaust apparatus (sensor arrangements for engine control F02D41/1439)} - F01N 2550/00: Monitoring or diagnosing the deterioration of exhaust systems - F01N 2560/08: the means being a pressure sensor - F01N 2590/08: for heavy duty applications, e.g. trucks, buses, tractors, locomotives - F01N 2900/0422: measuring the elapsed time - F01N 2900/1406: Exhaust gas pressure - 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) ## Abstract The invention relates to a method for automatically detecting clogging of a sensor pipe extending between a pressure sensor and an exhaust manifold of an internal combustion engine, wherein the pressure sensor enables to record a signal representative of the relative pressure over time. The method includes at least one of the following steps: a) determining, while the engine runs in a steady operation state, an average amplitude of oscillations of the signal over a first period of time, the sensor pipe being considered clogged when said average amplitude is lower than a first threshold; b) monitoring, from the time the engine has been turned off, the signal over a second period of time, the sensor pipe being considered clogged when the integral of the signal is greater than a second threshold. ## Claims ### Claim 1 A method for automatically detecting clogging of a sensor pipe extending between a pressure sensor and an exhaust manifold of an internal combustion engine, wherein the pressure sensor enables to record a signal representative of the relative pressure over time wherein the method includes at least one of the following steps: determining, while the engine runs in a steady operation state, an average amplitude of oscillations of the signal over a first period of time (T1), the sensor pipe being considered clogged when said average amplitude is lower than a first threshold; and monitoring, from the time the engine has been turned off, the signal over a second period of time (T2), the sensor pipe being considered clogged when the integral of the signal over said second period (T2) of time is greater than a second threshold. ### Claim 2 (depends on 1) The method according to claim 1, wherein the first period of time (T1) is comprised between 5 seconds and 10 seconds. ### Claim 3 (depends on 1) The method according to claim 1, wherein said second threshold is variable depending on the exhaust gas pressure at the time the engine is shut off. ### Claim 4 (depends on 1) The method according to claim 1, wherein the first threshold is variable depending on the operating point of the engine. ### Claim 5 (depends on 1) The method according to claim 1, wherein said first threshold is a percentage of an expected normal average amplitude, which is derived from a theoretical model or experiment. ### Claim 6 (depends on 1) The method according to any preceding claim 1, wherein said second threshold is a percentage of an expected normal pressure integral. ### Claim 7 (depends on 1) The method according to claim 1, wherein the second period of time, which corresponds to the period between the time at which the engine is shut off and the time at which an electronic control unit (ECU) of the engine is shut off, is comprised between 1 second and 10 seconds. ### Claim 8 (depends on 1) The method according to claim 1, wherein a signal is sent to the driver when the sensor pipe is detected as being clogged, such signal comprising a light that is displayed on the vehicle dashboard. ### Claim 9 (depends on 1) The method according to claim 1, wherein the steps of the method are iteratively implemented as long as the electronic control unit (ECU) of the engine is on. ### Claim 10 (depends on 1) The method according to claim 1, wherein the first time period (T1) is chosen to be superior to at least two successive combustion phases of the ignition cycle. ### Claim 11 (depends on 1) The method according to claim 1, wherein the first time period (T1) is set to be equal to the time it takes for the engine crankshaft to reach a certain Crank Angle Degree, which is inherent to the number of cylinders of the engine. ### Claim 12 (depends on 11) The method according to previous claim 11, wherein said certain Crank Angle degree is equal to 22.5 degrees for a 4-cylinder application and 15 degrees for a 6-cylinder application. ### Claim 13 (depends on 11) The method according to claim 11, comprising preliminary steps consisting in monitoring one or more operating parameters of the engine comprising i) the engine speed and torque or ii) the fuel consumption and in checking that said operating parameter(s) is or are stable before proceeding with step a). ### Claim 14 (depends on 1) An internal combustion engine assembly comprising an exhaust manifold, a pressure sensor and a sensor pipe extending between the exhaust manifold and the pressure sensor, wherein said engine assembly further includes an Electronic Control Unit (ECU) for detecting clogging of the sensor pipe, using the method according to claim 1. ### Claim 15 The internal combustion engine assembly according to preceding claim, wherein the internal combustion engine comprises a four-stroke engine. ### Claim 16 (depends on 13) The method combustion engine assembly according to claim 13, characterized in that wirings or wireless means connect the Electronic Control Unit (ECU) to the pressure sensor. ### Claim 17 (depends on 14) The method combustion engine assembly according to claim 14, wherein the Electronic Control Unit is configured for receiving one or more operating parameters of the engine comprising i) the engine speed and torque or ii) the fuel consumption and for processing the received information to check that said operating parameter(s) is or are stable over time before implementing step a) of the method. ### Claim 18 (depends on 14) A vehicle comprising an internal combustion engine assembly according to claim 14. ### Claim 19 (depends on 18) The vehicle according to claim 18, wherein the vehicle comprises a medium-duty or heavy-duty vehicle comprising a truck.