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.

Disclosed is a gas sensor element having an electrode containing a first metal as a predominant component and a lead containing a second metal as a predominant component. The electrode and the lead are connected directly at a connection boundary thereof, or connected indirectly via a connection joint. The connection boundary or joint includes a component region where either one of the first and second metals lower in specific gravity than the other of the first and second metals is contained in an amount ranging between those in the electrode and the lead.

A control system of an exhaust sensor controlling an exhaust sensor comprises a heater control part controlling a heater and a temperature estimating part estimating a temperature of an exhaust pipe around the exhaust sensor. The heater control part sets the target temperature to a first target temperature after startup of the internal combustion engine and until the estimated temperature of the exhaust pipe reaches a first exhaust pipe temperature, sets the target temperature to a second target temperature from when the estimated temperature of the exhaust pipe reaches the first exhaust pipe temperature to when it reaches a second exhaust pipe temperature, and sets the target temperature to an operating temperature of the electrochemical cell when the estimated temperature of the exhaust pipe reaches the second exhaust pipe temperature.

Methods and systems are provided for accurately inferring an exhaust temperature during steady-state and transient vehicle operation based on the duty cycle of an exhaust gas sensor heating element. A steady-state temperature is inferred based on an inverse of the duty cycle, and then adjusted with a transfer function that compensates for transients resulting from changes in vehicle speed, and load, and for the occurrence of tip-in and tip-out events. The inferred temperature can also be compared to a modeled temperature to identify exhaust temperature overheating conditions, so that mitigating actions can be promptly performed.

Provided is a flat plate-type oxygen sensor element. The flat plate-type oxygen sensor element according to an exemplary embodiment of the present invention includes: a first electrolyte layer having a sensing electrode exposed to a target gas; a second electrolyte layer on which a reference electrode is disposed; and a heating unit having a heating resistor surrounded by an insulating layer and disposed between the sensing electrode and the reference electrode, wherein the heating unit is disposed so that the heating resistor is located at a position ranging from 40 to 60% of a total height from an upper surface of the first electrolyte layer to a lower surface of the second electrolyte layer.

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.

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.

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 of heating the cells to combust and remove the PM, a storage unit that stores a reference reduction amount, which is an electrostatic capacitance reduction amount between the electrode members in a case where the filter regeneration is executed in a state where the PM is not flowing into the filter member, and estimation units that estimate a PM amount based on (a) an actual electrostatic capacitance change amount between the electrode members during a regeneration interval period, and (b) a difference between an actual electrostatic capacitance reduction amount between the electrode members and the reference reduction amount during a filter regeneration period.

A method of operating a particulate matter sensor having a pair of spaced apart electrodes and a heater includes accumulating particulate matter on the sensor, thereby changing resistance between the pair of spaced apart electrodes. The particulate matter sensor includes a sensing cycle that includes a deadband zone, followed by an active zone, which is followed by a regeneration zone in which the heater is operated to elevate the temperature of the particulate matter sensor to a first predetermined temperature for a first predetermined time in order to oxidize the particulate matter accumulated on the particulate matter sensor. The method also includes interrupting the sensing cycle with a modified regeneration zone which is either higher in temperature or length than the regeneration zone.

Methods, systems, and vehicles that control the temperature of a device included in the vehicle are presented herein. The temperature of the device is controlled by ventilating the device with drivetrain air, such as transmission cooling air. In some embodiments, the device is at a greater temperature than the drivetrain air, which cools the device. In other embodiments, the device is at a lesser temperature than the drivetrain air, which heats the device. The drivetrain air is provided to the device through an exhaust duct coupled to the vehicle's transmission. The drivetrain exhaust air is preferably circulated by the transmission. The transmission may be a continuously variable transmission. The device may be an oxygen sensor that is coupled to an engine exhaust pipe. The oxygen sensor is thermally coupled to the engine exhaust and the engine exhaust pipe, which are at greater temperatures than the transmission exhaust air.