# US 10,309,944 B2 · Electrostatic PM sensor electrode diagnostics > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,309,944 B2 - Document ID: US10309944B2 - Status: Granted - Kind: B2 - Application number: 15/256,890 - Filed: 2016-09-06 - Published: 2018-03-08 - Granted: 2019-06-04 - Earliest claimed: 2016-09-06 - Assignees: Ford Global Technologies, LLC - Applicants: Ford Global Technologies, LLC - Inventors: Michael Brendan Hopka; David John Kubinski; David Bilby; Michiel J. Van Nieuwstadt - Web page: https://patentgrep.com/patent/US10309944B2 ## CPC - G01N 33/007: {Arrangements to check the analyser (calibrating gas analysers G01N33/0006)} - F01N 11/00: Monitoring or diagnostic devices for exhaust-gas treatment apparatus - F01N 13/008: {Mounting or arrangement of exhaust sensors in or on exhaust apparatus (sensor arrangements for engine control F02D41/1439)} - G01N 33/0036: {specially adapted to detect a particular component (physical analysis of gaseous biological material G01N33/497)} - F01N 2550/04: Filtering activity of particulate filters - F01N 2560/05: the means being a particulate sensor - Y02A 50/20: Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters - Y02T 10/40: Engine management systems - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - 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) - Y02A: TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract Particulate matter (PM) sensors and diagnostics performed using the PM sensors are disclosed. The PM sensors and diagnostics may be used in exhaust systems, such as vehicle exhaust systems, to detect soot. In at least one embodiment, an electrostatic particulate matter (PM) sensor is provided including first and second spaced apart electrodes forming a bulk gap therebetween having a bulk distance and a localized gap therebetween having a localized distance less than the bulk distance. A controller may be configured to control a voltage between the electrodes to induce an electrostatic discharge at the localized gap at a lower voltage than at the bulk gap. Various diagnostics may be performed using the disclosed PM sensors, including a wiring/continuity diagnostic, a soot detection plausibility diagnostic, and/or an installation diagnostic. ## Claims ### Claim 1 An electrostatic particulate matter (PM) sensor, comprising: first and second spaced apart electrodes forming a bulk gap therebetween having a bulk distance and a localized gap therebetween having a localized distance less than the bulk distance; and a controller configured to maintain a voltage between the electrodes that is constant during a first operating state and to increase the voltage between the electrodes during a second operating state to induce an electrostatic discharge at the localized gap if there are no electrical faults in the PM sensor. ### Claim 2 (depends on 1) The PM sensor of claim 1, wherein the controller is configured to increase the voltage between the electrodes to at least 50% above the constant voltage of the first operating state. ### Claim 3 (depends on 1) The PM sensor of claim 1, wherein the localized gap is formed by a protrusion extending from one of the first or second electrodes towards the other. ### Claim 4 (depends on 3) The PM sensor of claim 3, wherein the localized gap is formed by a protrusion extending from each of the first and second electrodes towards the other. ### Claim 5 (depends on 3) The PM sensor of claim 3, wherein the protrusion is integrally formed with the electrode from which it extends. ### Claim 6 An electrostatic particulate matter (PM) sensor, comprising: first and second spaced apart electrodes forming a bulk gap therebetween having a bulk distance and a localized gap therebetween having a localized distance less than the bulk distance; and a controller configured to maintain a voltage between the electrodes that is constant during a first operating state and during a second operating state, the controller is configured to incrementally increase the voltage between the first and second electrodes above the constant voltage of the first operating state until a current detected between the electrodes is greater than a discharge threshold current. ### Claim 7 (depends on 6) The PM sensor of claim 6, wherein a breakdown voltage at which the current is detected is compared to a calculated breakdown voltage of an exhaust gas passing through the PM sensor at the localized gap; wherein, if the breakdown voltage is greater than the calculated breakdown voltage an installation fault flag is generated. ### Claim 8 (depends on 7) The PM sensor of claim 7, wherein the controller is configured to perform the steps of incrementally increasing the voltage and comparing the breakdown voltage to the calculated breakdown voltage multiple times at different exhaust gas temperatures; wherein, if the breakdown voltage is greater than the calculated breakdown voltage at least a threshold number of times of the multiple times, the installation fault flag is generated. ### Claim 9 (depends on 6) The PM sensor of claim 6, wherein the controller is configured to incrementally increase the voltage continuously or in a step-wise manner. ### Claim 10 (depends on 6) The PM sensor of claim 6, wherein the localized gap is formed by a protrusion extending from one of the first or second electrodes towards the other. ### Claim 11 (depends on 10) The PM sensor of claim 10, wherein the localized gap is formed by a protrusion extending from each of the first and second electrodes towards the other. ### Claim 12 (depends on 10) The PM sensor of claim 10, wherein the protrusion is integrally formed with the electrode from which it extends.