A particulate matter sensor unit is configured to sense particulate matter included in exhaust gas of a vehicle. The particulate matter sensor unit includes: a sensing unit sensing the particulate matter in the exhaust gas; a holding unit including a plurality of holders covering an exterior of the sensing unit, a front outer surface of each holder being formed by a tapered inclination outer surface; a shell having a hollow portion therein so that the holding unit is inserted and fitted into the shell, an inclination inner surface being formed in the hollow portion to correspond to the inclination outer surface; a cap unit installed in front of the shell to cover a sensing body of the sensing unit and guiding a flow of the exhaust gas to go through the sensing body; and a cover fixed to a rear end of the shell to support the holding unit.

A method may comprise: positioning a pressure control valve (PCV) at an outlet of a fuel rail; positioning a volume control valve (VCV) at an inlet of a high pressure pump; and in response to an exhaust particulate matter (PM) level deviating from a target PM level, adjusting a fuel ratio of a first fuel and a second fuel delivered to an engine, and opening one of the PCV and the VCV. In this way, the fuel oxygen content may be adjusted to maintain a PM at or below a target level without a DPF over a broad range of engine designs and operating conditions, while maintaining fuel economy.

Methods and systems are provided for a particulate matter sensor positioned downstream of a diesel particulate filter in an exhaust system. In one example, a particulate matter sensor may include a spherical assembly including a hollow rod and a plurality of flow tubes connected to diametrically opposite ends of the assembly, and a sensor element positioned within the assembly, distal to the plurality of flow tubes, thus protecting the sensor element from contaminants and water droplets condensing at or near the plurality of flow tubes. In addition, the support rod may further include a drainage hole to flow larger particulates out the spherical assembly and out into the exhaust passage.

A particulate matter sensor is provided. The particulate matter sensor includes a particulate matter detection unit that has first and second electrodes separately disposed on a substrate and configured to generate capacitance to correspond to a quantity of a particulate matter accumulated between the first and second electrodes. A signal generator is configured to generate a frequency signal that determines a resonant frequency by the capacitance. A detection result processor is configured to detect a signal magnitude of a predetermined reference frequency in the frequency signal and distinguishes an exhaust level of the particulate matter based on a change of the signal magnitude.

Systems and methods are described for sensing particulate matter in an exhaust system of a vehicle. An example system comprises a first outer tube with a plurality of intake apertures on an upstream surface, a second inner tube with a plurality of intake apertures on a downstream surface, and a particulate matter sensor placed within the second inner tube. The second inner tube may be positioned within the first outer tube such that a central axis of the second inner tube is parallel to a central axis of the first outer tube.

Various embodiments include a method for the production of a sensor for an exhaust gas stream of an internal combustion engine, wherein the sensor comprises a first electrode and a second electrode. The method comprises: arranging a glass solder in a mold substantially between and substantially insulating the first electrode and the second electrode; arranging an insulating element in the mold in contact with a free surface of the glass solder; and finish molding the glass solder into a glass insulator together with the insulating element in a predetermined position relative to the first electrode and the second electrode. The insulating element shapes the glass insulator during the finish molding and at least partially isolates the glass insulator from the exhaust gas of the internal combustion engine during a measuring operation of the sensor.

In a failure diagnosis apparatus that carries out standard diagnosis processing in which a failure of the particulate filter is diagnosed by making a comparison between an output value of the PM sensor at the time when a predetermined period of time has passed from a point in time at which sensor regeneration processing for removing the particulate matter deposited on an insulation layer of the PM sensor has ended, and a predetermined threshold value, the standard diagnosis processing is carried out in the case where rich spike processing according to the in-cylinder rich control is not carried out during the predetermined period of time, whereas the rich spike processing according to the in-cylinder rich control is carried out during the predetermined period of time, the standard diagnosis processing is not carried out.

Methods and systems are provided for predicting response time of a particulate matter (PM) sensor and resetting the PM sensor upon completion of response time prediction, independent of actual or predicted soot load on PM sensor. Soot accumulation data collected during steady state vehicle operation may be fitted with a time-based polynomial function and sensor output and regeneration schedule may be estimated from the curve fit even if the overall signal is noisy.

A chemical species mass flow meter measurement system for use in fluid mixture streams includes a chemical species concentration detection analyzer physically located within a fluid volume flow rate sensing probe along with bulk temperature and pressure sensing devices for relating to standard conditions. The system uses concentration detection analyzers specifically suited to the intended application. Applications include the measurement of exhaust mass emissions from vehicles, the fuel economy of vehicles, as well as the measurement of the mass flow rate of chemical species of interest in general industrial processes.

The sensor includes a filter member including cells that trap PM in exhaust gas, electrode members arranged to face each other with the cell interposed and forming a capacitor, an electric heater that executes, when an amount of PM has accumulated in the cells, filter regeneration for combusting and removing the PM, a temperature sensor that acquires the temperature of the filter member, a storage unit that stores therein a reference temperature, which is the temperature of the filter member where the filter regeneration has been executed in a state in which PM is not flowing into the filter member, and estimation units that estimate a PM amount included in the exhaust gas based on (a) an electrostatic capacitance change amount between the electrode members during a regeneration interval and (b) a difference between the temperature acquired by the temperature sensor and the reference temperature during a filter regeneration interval.