Patent application number | Description | Published |
20110107815 | Method and System for Diagnostics of a Particulate Matter Sensor - A diagnostic method and system is described for diagnosing an operating condition of a conductive particulate matter sensor. The sensor has a substrate and two electrodes on the substrate adapted to collect particulate matter between the electrodes, thereby establishing an electrically conductive path through collected particulate matter between the electrodes that can be detected by measuring electrical resistance between the electrodes, R | 05-12-2011 |
20110109331 | Method and System for Heater Signature Detection Diagnostics of a Particulate Matter Sensor - A diagnostic method and system is described for diagnosing an operating condition of a conductive particulate matter sensor. The sensor has a substrate with electrical resistance that varies with temperature and two electrodes on the substrate adapted to collect particulate matter between the electrodes, thereby establishing an electrically conductive path through collected particulate matter between the electrodes that can be detected by measuring electrical resistance between the electrodes, R | 05-12-2011 |
20120119759 | SELF DIAGNOSTICS OF A PARTICULATE MATTER SENSOR - A particulate matter sensor includes first and second electrodes spaced from each other with a bias resistor connected between the first and second electrodes. The particulate matter sensor allows an open circuit fault condition in the sensor or in the connectors or wiring to the sensor to be detected. A sensing system using the particulate matter sensor and a method for diagnosing faults in a sensing system are also provided. | 05-17-2012 |
20120324982 | PARTICULATE MATTER DETECTION METHOD FOR A PARTICULATE MATTER SENSOR - A method of detecting particulate matter on a particulate matter sensor includes the steps of measuring an electrical characteristic associated with the sensor, determining a value corresponding to the impedance across the sensor, and compensating the impedance for the temperature at which it was determined. The method further includes determining an estimate of the total amount of particulate matter accumulated while limiting the effects of large particles captured on the sensor or blown off the sensor. The information produced by the method may be used to provide diagnostic information regarding a particulate control system. | 12-27-2012 |
20130000678 | METHOD AND SYSTEM FOR CONTAMINATION REMOVAL FROM A PARTICULATE MATTER SENSOR - A method and system is described for removing contamination from a conductive particulate matter sensor. The sensor has a substrate with two electrodes on the substrate configured to collect particulate matter between the electrodes, thereby establishing an electrically conductive path through collected particulate matter between the electrodes that can be detected by measuring electrical resistance between the electrodes. The method includes heating the sensor to a first temperature for a first duration of time, wherein the first temperature and first time are sufficient to remove collected particulate matter from the sensor. The method further includes heating the sensor to a second temperature for a second duration of time, wherein the second temperature is higher than the first temperature, to remove contaminants that cannot be removed by heating to the first temperature for the first duration of time. | 01-03-2013 |
20130002271 | METHOD AND SYSTEM FOR CONTAMINATION SIGNATURE DETECTION DIAGNOSTICS OF A PARTICULATE MATTER SENSOR - A diagnostic method and system is described for diagnosing an operating condition of a conductive particulate matter sensor. The sensor has a substrate with electrical resistance that varies with temperature and two electrodes on the substrate adapted to collect particulate matter between the electrodes, thereby establishing an electrically conductive path through collected particulate matter between the electrodes that can be detected by measuring electrical resistance between the electrodes, R | 01-03-2013 |
20130256296 | TEMPERATURE MEASUREMENT METHOD FOR A HEATED SENSOR - A method for determining the temperature of a sensor that comprises a heater is provided. The method includes the steps of applying a voltage to the heater and measuring the voltage applied to the heater and the current through the heater during a first time interval, and removing the applied voltage from the heater and leaving the heater unpowered for a second time interval. The method further includes the steps of calculating the resistance of the heater using the measured voltage and current, and determining the temperature of the sensor from the resistance using a predetermined relationship. The first time interval is selected to be sufficiently short in duration and the second time interval is selected to be sufficiently long so as to not significantly raise the temperature of the heater. The sensor temperature so determined can be used to perform diagnostic functions for a system that includes the sensor. | 10-03-2013 |
20130257460 | PARTICULATE MATTER SENSOR WITH TWO PAIRS OF SENSING ELECTRODES AND METHOD OF USING SAME - A particulate matter sensor includes a first pair of sensing electrodes with a gap therebetween and a second pair of sensing electrodes with a gap therebetween. A method for determining an amount of soot on the particulate matter sensor includes determining the electrical resistance between the first pair of electrodes and the electrical resistance between the second pair of electrodes. The amount of soot deposited on the particulate matter sensor is determined based on the electrical resistance values. The time rate of change of resistance between the first pair of electrodes and the time rate of change of resistance between the second pair of electrodes are determined. The first and second rates of change are compared to each other and to threshold values, and the determination of soot amount may be modified depending on the results of these comparisons. | 10-03-2013 |