# US 12,768,295 B2 · Method and device for detecting pressure difference of particulate filter > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,768,295 B2 - Document ID: US12768295B2 - Status: Granted - Kind: B2 - Application number: 18/870,110 - Filed: 2022-06-02 - Published: 2026-08-27 - Granted: 2026-10-20 - Earliest claimed: 2022-06-02 - Assignees: Nissan Motor Co., Ltd. - Applicants: Nissan Motor Co., Ltd. - Inventors: Akikazu Sakai; Hideyuki Suzuki - Web page: https://patentgrep.com/patent/US12768295B2 ## CPC - F01N 11/002: {the diagnostic devices measuring or estimating temperature or pressure in, or downstream of the exhaust apparatus} - F01N 9/002: {of filter regeneration} - F01N 2550/04: Filtering activity of particulate filters - F01N 2560/08: the means being a pressure sensor - F01N 2560/14: having more than one sensor of one kind - 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 A particulate filter differential pressure sensing method is provided. The method includes sensing, by an upstream pressure sensor, a first pressure on an upstream side of a particulate filter disposed in an exhaust passage of an internal combustion engine; sensing, by a downstream pressure sensor, a second pressure on a downstream side of the particulate filter; and calculating an upstream-to-downstream differential pressure of the particulate filter. The method further includes correcting a sensed value of the first pressure or the second pressure so as to reduce a difference in waveform phase between the first pressure and the second pressure; and implementing the calculation of the upstream-to-downstream differential pressure based on the corrected sensed value of the first pressure or the second pressure. ## Claims ### Claim 1 A particulate filter differential pressure sensing method comprising: sensing by an upstream pressure sensor a first pressure on an upstream side of a particulate filter disposed in an exhaust passage of an internal combustion engine; sensing by a downstream pressure sensor a second pressure on a downstream side of the particulate filter; calculating an upstream-to-downstream differential pressure of the particulate filter; correcting a sensed value of the first pressure or the second pressure so as to reduce a difference in waveform phase between the first pressure and the second pressure; and implementing the calculation of the upstream-to-downstream differential pressure based on the corrected sensed value of the first pressure or the second pressure; wherein a first for-sensor pipe that branches from an exhaust pipe provided with the particulate filter and leads to the upstream pressure sensor and a second for-sensor pipe that branches from the exhaust pipe and leads to the downstream pressure sensor are different in path length from each other; and wherein the particulate filter differential pressure sensing method comprises calculating the corrected sensed value by retarding the sensed value of one of the upstream pressure sensor and the downstream pressure sensor corresponding to one of the first for-sensor pipe and the second for-sensor pipe that is shorter in path length than the other. ### Claim 2 (depends on 1) The particulate filter differential pressure sensing method as claimed in claim 1, comprising determining based on the calculated upstream-to-downstream differential pressure whether or not the particulate filter is damaged. ### Claim 3 (depends on 1) The particulate filter differential pressure sensing method as claimed in claim 1, comprising performing a control of regeneration of the particulate filter based on the calculated upstream-to-downstream differential pressure. ### Claim 4 A particulate filter differential pressure sensing method comprising: sensing by an upstream pressure sensor a first pressure on an upstream side of a particulate filter disposed in an exhaust passage of an internal combustion engine; sensing by a downstream pressure sensor a second pressure on a downstream side of the particulate filter; calculating an upstream-to-downstream differential pressure of the particulate filter; correcting a sensed value of the first pressure or the second pressure so as to reduce a difference in waveform phase between the first pressure and the second pressure; implementing the calculation of the upstream-to-downstream differential pressure based on the corrected sensed value of the first pressure or the second pressure; calculating a phase compensation time period based on rotation speed of the internal combustion engine, wherein the phase compensation time period corresponds to the difference in waveform phase; and setting the corrected sensed value to a sensed value of one of the first pressure and the second pressure the phase compensation time period before, wherein the one of the first pressure and the second pressure is more advanced in waveform phase than the other. ### Claim 5 (depends on 4) The particulate filter differential pressure sensing method as claimed in claim 4, comprising: calculating an exhaust gas temperature; and correcting the phase compensation time period based on the exhaust gas temperature. ### Claim 6 (depends on 4) The particulate filter differential pressure sensing method as claimed in claim 4, comprising: calculating an exhaust gas flow rate; and correcting the phase compensation time period based on the exhaust gas flow rate. ### Claim 7 (depends on 4) The particulate filter differential pressure sensing method as claimed in claim 4, comprising determining based on the calculated upstream-to-downstream differential pressure whether or not the particulate filter is damaged. ### Claim 8 (depends on 4) The particulate filter differential pressure sensing method as claimed in claim 4, comprising performing a control of regeneration of the particulate filter based on the calculated upstream-to-downstream differential pressure. ### Claim 9 A particulate filter differential pressure sensing device comprising: an upstream pressure sensor structured to sense a first pressure on an upstream side of a particulate filter disposed in an exhaust passage of an internal combustion engine; a downstream pressure sensor structured to sense a second pressure on a downstream side of the particulate filter; a phase compensation section configured to correct a sensed value of the first pressure or the second pressure so as to reduce a difference in waveform phase between the first pressure and the second pressure; and a differential pressure calculation section configured to calculate an upstream-to-downstream differential pressure of the particulate filter based on the corrected sensed value of the first pressure or the second pressure; wherein a first for-sensor pipe that branches from an exhaust pipe provided with the particulate filter and leads to the upstream pressure sensor and a second for-sensor pipe that branches from the exhaust pipe and leads to the downstream pressure sensor are different in path length from each other; and wherein the phase compensation section is configured to calculate the corrected sensed value by retarding the sensed value of one of the upstream pressure sensor and the downstream pressure sensor corresponding to one of the first for-sensor pipe and the second for-sensor pipe that is shorter in path length than the other. ### Claim 10 A particulate filter differential pressure sensing device comprising: an upstream pressure sensor structured to sense a first pressure on an upstream side of a particulate filter disposed in an exhaust passage of an internal combustion engine; a downstream pressure sensor structured to sense a second pressure on a downstream side of the particulate filter; a phase compensation section configured to correct a sensed value of the first pressure or the second pressure so as to reduce a difference in waveform phase between the first pressure and the second pressure; and a differential pressure calculation section configured to calculate an upstream-to-downstream differential pressure of the particulate filter based on the corrected sensed value of the first pressure or the second pressure; wherein the phase compensation section is configured to: calculate a phase compensation time period based on rotation speed of the internal combustion engine, wherein the phase compensation time period corresponds to the difference in waveform phase; and set the corrected sensed value to a sensed value of one of the first pressure and the second pressure the phase compensation time period before, wherein the one of the first pressure and the second pressure is more advanced in waveform phase than the other.