DE102017117140A1 - Method and system for capturing particulate matter in exhaust gas - Google Patents

Abstract

Methods and systems for capturing particulate matter through a particulate matter sensor disposed downstream of a diesel particulate filter in an exhaust system are provided. In one example, a method may include increasing an opening of an inlet of the particulate matter sensor when an exhaust gas flow rate falls below a threshold to allow more particulates to enter the particulate matter sensor, and further including decreasing the opening of the inlet when the exhaust gas flow rate exceeds the threshold to reduce the particles that enter the sensor. By adjusting the amount of particulate entering the sensor based on the exhaust gas rate and further including a plurality of flow diverters in the sensor, the deposition rate of the sensor and thus the sensitivity of the sensor to the exhaust gas flow rate may be at a desired level and independent of the sensor Exhaust gas flow rate can be maintained.

Description

area

The present description generally relates to the design and use of resistive particulate matter (FS) sensors in an exhaust stream.

Background / Summary

Diesel combustion exhaust gas is a regulated emission. Diesel particulate matter (FS) is the particulate component of diesel exhaust gas that includes diesel soot and aerosols such as ash particles, metal grit particles, sulfates and silicates. When FS is released into the atomic sphere, it can take the form of single particles or chain aggregates, most of them in the invisible sub-micrometer range of 100 nanometers. Various technologies have been developed to identify and filter out FS in exhaust gas before the exhaust gas is released into the atmosphere.

For example, in vehicles having internal combustion engines, soot sensors, also known as FS sensors, may be used. An FS sensor may be upstream and / or downstream of a diesel particulate filter (DPF) and used to detect the FS load on the filter and for diagnostic operation of the DPF. Typically, the FS sensor may detect a particulate soot load based on a correlation between a measured change in electrical conductivity (or resistance) between a pair of electrodes placed on a planar substrate surface of the sensor, the amount of FS between is positioned the measuring electrodes. In particular, the measured conductivity provides a measure of soot accumulation. Therefore, the sensitivity of the FS sensor to measure FS in the exhaust gas may be related to the exhaust gas flow rate, where an increased exhaust gas flow rate results in increased sensitivity of the FS sensor and reduced exhaust flow results in reduced sensitivity of the FS sensor. Due to this increased dependence on the exhaust gas flow rate, the FS sensor trapping the FS exiting the DPF may not truly reflect the DPF filtering capabilities. In addition, FS sensors may be prone to contamination from the impact of water droplets and / or larger particles present in the exhaust gases, thereby affecting the sensitivity of the FS sensor and resulting in erroneous FS sensor outputs.

An exemplary embodiment for FS sensors is in US 8225648B2 shown by Nelson. In that document, an FS sensor includes a flow diverter and a barrier positioned around an FS sensor element to filter out the larger particles so that they do not impact the FS sensor element. The barrier thus serves to prevent larger particles in the exhaust stream from impacting the FS sensor element, thereby reducing sensitivity variations of the FS sensor due to large particles depositing on the FS sensor element.

However, the inventors of the present invention have recognized potential problems with such an approach. As one example, the sensitivity of the FS sensor may continue to depend on the incoming exhaust gas flow rate. In one example, the problems described above may be solved in part by a method of adjusting an amount of opening of an inlet to a particulate matter sensor positioned in an exhaust stream in response to an exhaust gas flow rate of the exhaust stream upstream of the particulate matter sensor; and flowing exhaust gas past a plurality of flow plates toward a particulate matter sensor element positioned proximate to the plurality of flow plates. The plurality of flow plates may be positioned near a sensor element. Larger particles may be blocked on the plates as exhaust gas flows through the plurality of flow plates and, in addition, smaller soot particles may be directed toward the sensor element and evenly distributed across the electrodes of the sensor element. In addition, by adjusting the degree of opening of the inlet based on the exhaust gas flow rate, the amount of particulates entering and thus deposited over a sensor element positioned therein may be controlled. In this way, the sensitivity of the particulate matter sensor may become independent of the exhaust gas flow rate, and the FS sensor output may begin to more accurately and reliably measure the DPF filtering capabilities.

As an example, if the exhaust gas flow rate falls below a threshold, the extent of opening of the inlet of the FS sensor may be increased to allow more exhaust gas to enter the FS sensor for subsequent deposition on an FS sensor element which is within the FS sensor is positioned. When the exhaust gas flow rate exceeds the threshold, the amount of opening of the inlet may be decreased to reduce the exhaust gas entering the FS sensor. Here, increasing and decreasing the degree of opening of the inlet can be regulated by adjusting (e.g., rotating) a movable flow control positioned at the inlet. In this way, the amount of exhaust gas and thus the amount of particles, the deposited on the FS sensor element which is positioned near an outlet of the FS sensor, becoming independent of the incoming exhaust gas flow rate, thereby more accurately and reliably measuring the FS leaving the DPF. Further, larger particles and / or water droplets may be trapped by the first flow diverter and the plurality of flow plates positioned within the FS sensor. Thus, the FS sensor element can be protected from the impact of water droplets and larger particles. Overall, these characteristics of the sensor may cause an output of the FS sensor to be more accurate, thereby increasing the accuracy of estimating particulate loading on a particulate filter.

It is understood that the foregoing summary is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not intended to identify important or essential features of the claimed subject matter, the scope of which is defined solely in the claims which follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that overcome the disadvantages listed in the foregoing or in any part of this disclosure.

Brief description of the drawings

1 FIG. 12 shows a schematic diagram of an engine and associated particulate matter (FS) sensor positioned in an exhaust flow. FIG.

The 2A - 2 B 10 show enlarged views of the FS sensor, wherein an intake port is increased or decreased based on an exhaust gas flow rate.

2C shows an exemplary embodiment of the FS sensor having a plurality of parallel flow plates positioned proximate an outlet of the FS sensor.

The 2D - 2E 12 show cross-sectional views of two exemplary flow plates of the plurality of flow plates.

2F FIG. 12 shows an exemplary embodiment of the FS sensor having a plurality of angled flow plates positioned near the outlet of the FS sensor. FIG.

3 FIG. 10 is a flowchart depicting a method of adjusting the inlet opening of the FS sensor based on the exhaust gas flow rate and flowing exhaust gas through the plurality of flow plates toward a sensor element of the FS sensor.

4 shows a diagram illustrating a method for performing the regeneration of the FS sensor.

5 FIG. 10 is a flowchart depicting a method of diagnosing leaks in a particulate filter positioned upstream of the FS sensor assembly. FIG.

6 FIG. 12 shows an exemplary relationship between the opening of the inlet of the FS sensor and an FS sensor load based on the exhaust gas flow rate.

Detailed description

The following description relates to the detection of particulate matter (FS) in an exhaust stream of an engine system, such as an engine system as disclosed in US Pat 1 is shown. An FS sensor disposed in an exhaust passage of the engine system may include a flow controller and a first flow diverter positioned proximate an inlet of the FS sensor. Opening of the inlet of the FS sensor may be adjusted based on the exhaust gas flow rate by rotating the flow control of the FS sensor, as in FIGS 2A and 2 B shown. In a first exemplary embodiment, the FS sensor may include a plurality of parallel flow plates separated by a space and stacked between the inlet and an outlet of the FS sensor, as in FIG 2C shown. The plurality of flow plates may include semi-circular disks coupled to a side surface of the FS sensor and having openings (as shown in cross-sectional views of FIGS 2C and 2D shown) configured to direct exhaust toward a sensor element of the FS sensor. In a second exemplary embodiment, the plurality of flow plates may be angled relative to one another and interposed between the inlet port and the sensor element, as in FIG 2F shown. A controller may be configured to perform a control routine, such as the routine off 3 for adjusting an amount of opening of the intake port of the FS sensor based on the exhaust gas flow rate. In addition, the controller may use the FS sensor (as in the in 4 3) to allow sustained FS detection and to perform a diagnosis on a particulate filter positioned upstream of the FS sensor based on an output of the FS sensor (as shown in FIG 5 shown). An exemplary relationship between opening the FS Sensor inlet and the FS sensor load based on the exhaust gas flow rate is with respect to 6 displayed. In this way, by adjusting the opening of the inlet based on the exhaust gas flow rate, the sensitivity of the FS sensor may become independent of the incoming exhaust gas flow rate. Furthermore, larger particles and / or water droplets may be trapped by the flow diverter and the plurality of flow plates. Thus, the FS sensor element can be protected from the impact of water droplets and larger particles. Overall, the operation of the FS sensor to estimate the filter capabilities of the DPF (and thereby detect DPF leaks) can be improved and compliance with exhaust emissions can be improved as FS in the exhaust can be more accurately and reliably detected.

1 shows a schematic illustration of a vehicle system 6 , The vehicle system 6 includes an engine system 8th , The engine system 8th can a motor 10 include a plurality of cylinders 30 having. The motor 10 includes an engine intake 23 and an engine outlet 25 , The engine intake 23 includes a throttle 62 fluidly via an inlet channel 42 with the engine intake manifold 44 is coupled. The engine output 25 includes an exhaust manifold 48 which eventually becomes an exhaust duct 35 leads the exhaust gas to the atmosphere. The throttle 62 can in the intake 42 disposed downstream of a charging device, for example, a turbocharger (not shown), and upstream of an aftercooler (not shown). If present, the aftercooler may be configured to reduce the temperature of the intake air that is compressed by the charging device.

The engine output 25 may be one or more emission control devices 70 include, which may be attached to a short coupled position in the outlet. One or more emission control devices may include a three-way catalyst, NOx trap catalyst, SCR catalyst, etc. The engine output 25 can also use a diesel particulate filter (DPF) 102 which temporarily filters FS from incoming gases, that of the emission control device 70 arranged upstream. In one example, as shown in the diagram, the DPF 102 a diesel particulate retention system. The DPF 102 may have a monolithic structure made of, for example, cordierite or silicon carbide having a plurality of channels inside for filtering particulate matter from diesel exhaust gas. The exhaust gas from the exhaust tailpipe, from which, after passing through the DPF 102 FS was filtered, can be in an FS sensor 106 be measured and also in the emission control device 70 processed and via the exhaust duct 35 be ejected into the atmosphere. In the example shown, the FS sensor is 106 to a resistive sensor, the filter efficiency of the DPF 102 based on a change in the conductivity measured at the electrodes of the FS sensor estimates. A schematic view 200 of the FS sensor 106 is in 2 shown as described in more detail below.

The vehicle system 6 may also be the tax system 14 include. In the illustration, the control system receives 14 Information from a variety of sensors 16 (for which various examples are described here) and sends control signals to a plurality of actuators 81 (for which different examples are described here). In one example, the sensors 16 an exhaust flow rate sensor 126 configured to an exhaust gas flow rate through the exhaust passage 35 to measure an exhaust gas sensor (in the exhaust manifold 48 arranged), a temperature sensor 128 , a pressure sensor 129 (which of the emission control device 70 is arranged downstream) and an FS sensor 106 include. Other sensors, such as additional sensors for pressure, temperature, air-fuel ratio, exhaust gas flow rate, and composition may be located at various locations in the vehicle system 6 be coupled. As another example, the actuators may be fuel injectors 66 , a throttle 62 , DPF valves that control filter regeneration (not shown), a motor actuator that controls the FS sensor opening (eg, control opening of a valve or plate in an inlet of the FS sensor), and so forth. The tax system 14 can be a controller 12 include. The control 12 may be configured with computer readable instructions stored on a nonvolatile memory. The control 12 receives signals from the various sensors 1 , processes the signals and suspends the various actuators 1 to adjust engine operation based on the received signals and instructions stored on a memory of the controller. Exemplary routines are described herein with respect to FIG 3 - 5 described.

In relation to 2A - 2 B Turning now to schematic views of a first exemplary embodiment of a particulate matter (FS) sensor 201 (like the FS sensor 106 out 1 ). 2A shows a first schematic representation 200 of the FS sensor 201 with a flow control 238 in a first configuration and 2 B shows a second schematic representation 260 of the FS sensor 201 with the flow control 238 in a second configuration. The FS sensor 201 can be configured to measure FS mass and / or concentration in the exhaust and as such can be used with a Exhaust duct (eg as in 1 shown exhaust passage 35 ) upstream or downstream of a diesel particulate filter (such as the DPF) 102 who in 1 is shown).

As in the 2A - 2 B shown is the FS sensor 106 in the exhaust duct 235 arranged, wherein exhaust gases flow from a diesel particulate filter downstream position in the direction of a tailpipe, whereupon the arrows 246 indicate. The FS sensor 106 includes a protective tube 250 , which can serve as an FS sensor element 254 of the FS sensor 201 In addition, it serves to protect the exhaust gas flow via the FS sensor element 254 redirect as explained below.

The FS sensor element 254 closes a pair of planar interdigital electrodes 220 which form a "comb" structure. These electrodes may typically be made of metals such as platinum, gold, osmium, rhodium, iridium, ruthenium, aluminum, titanium, zirconium, and the like, as well as oxides, cements, alloys, and combinations thereof containing at least one of the above metals. The electrodes 220 be on a substrate 216 formed, which is typically made of highly electrically insulating materials. Possible electrically insulating materials may include oxides such as alumina, zirconia, yttria, lanthana, silica, and combinations comprising at least one of the above or similar materials capable of impeding electrical connection and physically protecting the pair of interdigital electrodes. The distance between the comb "tines" of the two electrodes can typically be in the range of 10 Microns to 100 Microns, with the line width of each individual "prong" at about the same value, the latter not required. As in the 2A - 2 B As shown, the interdigital electrodes extend 220 along a portion of the substrate 216 and cover this.

A positive electrode of the pair of interdigital electrodes 220 is with connecting wires 224 to a positive pole of a voltage source 228 an electrical circuit 258 connected. A negative electrode of the interdigital electrode pair 220 is via a connecting wire 222 with a measuring device 226 and further with a negative pole of the voltage source 228 the electrical circuit 258 connected. The connecting wires 222 and 224 , the voltage source 228 and the measuring device 226 are part of the electrical circuit 258 and outside the exhaust duct 35 housed (for example <1 meter away). Furthermore, the voltage source 228 and the measuring device of the electric circuit 258 by a controller, such as the controller 12 out 1 , can be controlled so that particulate matter collected at the FS sensor can be used to diagnose leaks in the DPF. Therefore, it may be in the measuring device 226 be any device that is capable of reading a change in resistance at the electrodes, for example a voltmeter. The resistance between the pair of electrodes 220 can begin to reduce, which is indicated by a decrease in the voltage passing through the measuring device 226 is measured when FS or soot particles settle between the electrodes. The control 12 may be able to control the resistance between the electrodes 220 as a function of the voltage coming from the measuring device 226 is measured, and a corresponding load of FS or soot on the planar electrodes 220 of the FS sensor 201 derive. By monitoring the load on the FS sensor 201 For example, the exhaust soot load downstream of the DPF can be determined and used to diagnose and control the condition and functionality of the DPF.

The FS sensor element 254 also includes a heating element 218 that enters the sensor substrate 216 to integrate. In alternative embodiments, the FS sensor element may be 254 no heating element 218 lock in. The heating element 218 may include, but is not limited to, a temperature sensor and heater. To possible materials for the heating and the temperature sensor, which is the heating element 218 platinum, gold, palladium and the like; and alloys, oxides and combinations comprising at least one of the above materials with platinum / alumina, platinum / palladium, platinum and palladium. The heating element 218 can be used to regenerate the FS sensor element 254 be used. In particular, under conditions in which the particulate matter or soot load of the FS sensor element 254 is above a threshold, the heating element 218 be operated so that the accumulated soot particles are burned from the surface of the sensor. During the regeneration of the FS sensor, the controller can 12 a voltage source 230 provide a voltage necessary for the operation of the heating element 218 is needed. In addition, the controller can switch 232 for a threshold time, close the voltage across the voltage source 230 to the heating element 218 apply to the temperature of the heating element 218 to increase. Thereafter, if the sensor electrodes are sufficiently clean, the controller may switch 232 open to heating the heating element 218 to end. By intermittently regenerating the FS sensor 201 can he be in a state (eg an unloaded or only partly loaded state) be recycled, which is better suited for collecting exhaust soot. In addition, accurate information associated with the exhaust soot level may be derived from the sensor regeneration, and this information may be used by the controller to diagnose leaks in the particulate filter. The sensitivity of the FS sensor may be due to large particles and / or water droplets attached to the FS sensor element 254 deposit, be affected. In addition, the sensitivity of the FS sensor element 254 further depend on the exhaust gas flow rate. Higher sensitivity is typically observed at higher exhaust gas flow, while lower sensitivity occurs at lower exhaust flow. It may be possible to filter out larger particles and water droplets, and a current-independent FS sensor by using a design for the protective tube 250 as described below.

The protective tube 250 may be a hollow cylindrical tube with an upstream tube wall 208 (eg, a wall facing the upstream direction) of a downstream pipe wall 206 (eg, a wall facing the downstream direction) and an upper surface 212 be. The upstream pipe wall 208 may be closer to a DPF than the downstream pipe wall 206 when positioned in an exhaust passage, such as the exhaust passage 235 who in 1 with the DPF positioned upstream of the FS sensor. Furthermore, exhaust gases passing through the exhaust duct 135 flow, first the upstream pipe wall 208 of the FS sensor. The upper surface 212 may also be an inserted part 252 through which the FS sensor element 254 and its accompanying electrical connections in protective tube 250 can be used, and can also be closed to the FS sensor element 254 to protect that in the FS sensor 201 is housed. The protective tube 250 can on the exhaust duct 35 via sensor projection 202 and 204 be attached, such that the central axis of the protective tube 250 along the Y axis, and also such that the central axis of the protective tube 250 perpendicular to the exhaust duct 35 and the exhaust gas flow through the exhaust passage. As in the 2A - 2 B extends the protective tube 250 into a section of the exhaust duct 35 , The depth to which the protective tube extends into the exhaust duct may depend on the diameter of the exhaust pipe. In some examples, the protective tube may extend up to about one third to two thirds of the diameter of the exhaust pipe. The bottom of the protective tube 250 can be incised at an angle (dashed line 210 ) to form an angled inlet which introduces an exhaust flow into the FS sensor 201 introduces. Here, the angled lower section ( 210 ) of the FS sensor 201 by cutting the protective tube 250 are formed at a diagonal angle of, for example, 30 ° or 45 ° with respect to the horizontal X-axis, as in FIG 2A shown. Therefore, the length of the upstream pipe wall 208 smaller than the length of the downstream pipe wall 206 , Thus, the angled lower section is used 210 of the protective tube 250 as an inlet to the FS sensor 201 and will henceforth be considered as an inlet 210 designated. The FS sensor 201 also includes an outlet 214 which is spaced from the inlet of the FS sensor 201 is positioned. The outlet 214 may be a single hole or a plurality of holes along one or more of a rear wall and a front wall of the protective tube 250 is positioned (not shown). Therefore, the front wall and the rear wall of the protective tube 250 Surfaces of the hollow cylindrical protective tube 250 be, extending from the upstream pipe wall 208 and the downstream pipe wall 206 differ. Although the outlet 214 the representation of 2A After an elliptical hole, other shapes and sizes of the outlet can 214 may also be used without departing from the scope of this disclosure.

The protective tube 250 further includes a first flow diverter 234 and a second flow diverter 236 attached to the inner wall (eg inner surface) of the hollow cylindrical protective tube 250 are attached. The first and second flow diverter 234 and 236 may consist of sections of a circular plate and on opposite sides of the interior of the protective tube 250 relative to the central axis of the protective tube 250 be positioned. For example, the first flow diverter 234 attached to the inner surface of the protective tube, which is the downstream tube wall 206 of the protective tube 250 corresponds, and the second flow diverter 236 may be attached to the inner surface of the protective tube, which is the upstream tube wall 208 of the protective tube 250 equivalent. Here is the first flow diverter 234 near the inlet 210 of the FS sensor 201 positioned and the second flow diverter is near the outlet 214 of the FS sensor 201 positioned. Thus, the first flow diverter is located 234 closer to the inlet 210 as the second flow diverter 236 and the second flow diverter 236 is closer to the outlet 214 as the first flow diverter 234 , The detection section of the FS sensor element 254 (eg the electrodes 220 ) can in the protective tube 250 be introduced, such that the detection portion of the sensor element 254 closer to the second flow diverter than the first flow diverter. Furthermore, the FS sensor element is located 254 closer to the outlet 214 as at the inlet 210 ,

One end of the second flow diverter 236 may be on the inner surface of the upstream pipe wall 208 of the protective tube 250 be attached while the opposite end of the second flow diverter 236 not on the wall of the protective tube 250 can be attached. For example, the opposite, unattached end of the second flow diverter is from the inner wall of the protective tube 250 does not and does not touch them. Here is the unattached end of the second flow diverter 236 closer to the outlet 214 of the FS sensor 201 as at the inlet 210 and is from the unattached end of the first flow diverter 234 spaced. Further, the detecting portion of the FS sensor element may be 254 closer to the unattached end of the second flow diverter 236 further apart from each of the fixed end of the second flow diverter 236 and the inner surface of the downstream pipe wall 208 , Still further, the detecting portion of the FS sensor element 254 at a distance from the unattached end of the second flow diverter 236 be separated, whereby a gap between the unattached end of the second Strömungsumleiters and the detecting portion of the FS sensor element 254 is trained. Thus, the unattached end of the second flow diverter is located 236 and the detecting portion of the FS sensor element 254 each closer together than the first flow diverter 234 and, for example, closer to the outlet 214 as at the inlet 210 of the FS sensor 201 , The second flow diverter 236 extends over a portion of the protective tube 250 , the unattached end of the second flow diverter 236 is however from the inner surface of the protective tube 250 spaced away. Those skilled in the art will appreciate, given the present disclosure, that a plurality of second flow diverters are within the FS sensor 201 can be positioned. In an in 2C In the exemplary embodiment shown, a plurality of parallel flow diverters (eg, configured as semicircular flow plates) may be positioned proximate the sensor element, with each plate positioned parallel to all other plates, although different plate surface areas may be provided by different plates. In another exemplary embodiment, a plurality of angled flow plates may be positioned proximate the sensor element, as in FIG 2F shown.

Similarly, one end of the first second flow diverter 234 on the inner surface of the downstream pipe wall 206 of the protective tube 250 be attached while the opposite end of the first flow diverter 234 not on the wall of the protective tube 250 can be attached. For example, the opposite, unattached end of the first flow diverter is from the inner wall of the protective tube 250 does not and does not touch them. Here is the unattached end of the first flow diverter 234 closer to the inlet 210 of the FS sensor 201 as at the outlet 214 and is from the unattached end of the second flow diverter 236 spaced. In some embodiments, the lengths of the flow diverters 234 and 236 be determined, which are determined as the distances at which the flow diverter along the X-axis in the cavity of the protective tube 250 extend. In other embodiments, the lengths of the flow diverters may vary 234 and 236 differ from each other, wherein one of the flow diverter (the first / the second) can extend longer in the cavity of the protective tube than the other flow diverter (the second / the first).

Further, the unattached ends of each of the first and second flow diverters form 234 and 236 Openings from which exhaust gas flows past. As in the 2A - 2 B As shown, the first opening is between the unattached end of the first flow diverter 234 is formed, and the second opening formed between the unattached end of the second Strömungsumleiters 236 is formed on opposite sides of the protective tube 250 relative to the central axis. Furthermore, the first flow diverter extends 234 from the inner wall of the protective tube 250 in a first direction and the second flow diverter 236 extends from the inner wall of the protective tube 250 in a second direction opposite to the first direction.

The first flow diverter 234 is from the second flow diverter 236 separated by a space / distance. The FS sensor element 254 is between the first flow diverter 234 and the second flow diverter 236 positioned, such that the detection portion of the FS sensor element in a space between the first flow diverter 234 and the second flow diverter 236 extends. Here is the detecting portion of the FS sensor element 254 directed in one direction, for example, the incoming exhaust gas flow 246 is opposite. The electrodes 220 of the FS sensor element 254 point in the direction of the incoming exhaust gas flow 246 (For example, in the direction of the upstream pipe wall 208 ).

Typically, the FS sensors suffer from the problem of the sensitivity of the FS sensor to the exhaust gas flow rate through the duct in which the sensor is coupled, increasing the sensitivity of the FS sensor when the exhaust gas flow rate is above a threshold, and so on subsequently decreased, when the exhaust gas flow rate is below the threshold. It may be possible to adjust the opening of the FS sensor as described below to increase or decrease the opening of the FS sensor based thereon when the exhaust gas flow is above or below a threshold, whereby the dependence of the sensitivity on the exhaust gas flow rate is reduced.

The protective tube 250 also includes a flow control 238 that are near one or more of the inlet 210 and the first flow diverter 234 is positioned. A size of the inlet opening in an interior of the FS sensor 201 is controlled, for example, by the position of the flow control with respect to the first flow diverter. Therefore, the size of the inlet port (or the amount of opening of the inlet) controls the FS sensor 201 a quantity of exhaust gas flow through the inlet 210 and in the interior of the FS sensor. As the amount of opening of the inlet is increased, more exhaust gas flows into the FS sensor, and as the amount of opening of the inlet of the FS sensor is reduced, the flow of exhaust gas into the FS sensor is restricted. Enlarging and reducing the inlet opening of the FS sensor can be accomplished by moving and / or rotating the flow control 238 be enabled as described below. Therefore, increasing and decreasing the inlet opening results in a more consistent rate of exhaust gas flow to the sensor element 254 , As a result, the sensitivity of the FS sensor can be maintained at a more consistent level and the dependence of the sensor on the flow rate can be reduced. In this way, the dependence of the sensitivity of the FS sensor on the exhaust gas flow rate can be reduced.

As in the 2A - 2 B shown is the flow control 238 a movable plate, with the upstream pipe wall 208 of the protective tube 250 about a joint 240 is coupled to one end of the movable plate, and it is also attached to any additional structure at the opposite end of the movable plate or coupled thereto. In alternative embodiments, the flow control 238 a flap valve or other type of adjustable elements designed to reduce the amount of opening of the inlet 210 adjust.

The unattached end of the movable plate is near the unattached end of the first flow diverter 234 , A distance separating the unattached end of the first flow diverter 234 from the unattached end of the movable flow control plate 238 separates, creates a gap, or an inlet opening 248 , between the flow control 238 and the first flow diverter 234 , When the flow control 238 closer to the first flow diverter 234 is moved, whereby the distance is reduced, the unattached end of the first flow diverter 234 from the unattached end of the movable flow control plate 238 separates, becomes the inlet opening 248 reduced. When the flow control 238 is moved in the opposite direction away from the first flow diverter 234 , the inlet opening 248 of the FS sensor increases. The joint 240 which is an end to the flow control 238 with the wall of the protective tube 250 is on the upstream side of the FS sensor 201 positioned and with the upstream pipe wall 208 of the protective tube 250 coupled. The flow control 238 is pivoted to move around an axis of the joint 240 to turn. As in the 2A - 2 B shown, the joint becomes 240 through a motor actuator 256 actuated and the motor actuator 256 For example, it may be an electric motor actuator. In alternative embodiments, the actuator may be used to actuate the flow control 238 an alternative type of actuator that is in electronic communication with the controller.

In some embodiments, the first flow diverter 234 on the upstream pipe wall 208 be attached, the second flow diverter may be on the downstream pipe wall 206 be attached and the flow control can be on the downstream wall 206 be attached. In such an embodiment, the FS sensor element 254 pointing in the same direction as the arrow, for an incoming exhaust gas flow 246 is specified. In some example embodiments, a plurality of flow diverters may be positioned along the inner surface of the protective tube to move the particles toward the FS sensing element 254 to lead, as in the 2C and 2F shown.

The control 12 may be signals for adjusting the position of the flow control to the motor actuator 256 send. These signals may be commands for rotating the flow control in the direction of the first flow diverter 234 and get away from it. For example, if the exhaust gas flow rate is higher than a threshold rate, the controller may 12 Signals to the motor actuator 256 which in turn actuates the joint, causing the flow control 238 is rotated in a first direction, which reduces the inlet opening (as by the position of the flow control 238 and the smaller inlet opening 248 in 2 B shown as will be discussed in more detail below). As an example, the controller 12 Signals to the motor actuator 256 to rotate the flow control 30 ° counterclockwise about the X-axis when the exhaust gas flow rate is higher than the threshold. Therefore, that can Extent of opening depend on the exhaust gas flow rate. However, if the exhaust flow rate falls below the threshold, then the controller may send signals to the engine actuator 256 for rotating the flow control in a second direction, thereby increasing the inlet opening (as through the larger inlet opening 248 in 2A shown). Therefore, the second direction may be opposite to the first direction, and rotating the flow control may include actuating the joint, thereby rotating the flow control in the second direction. As an example, the controller 12 the motor actuator 256 command the flow control to rotate 30 ° clockwise about the x-axis as the exhaust flow rate falls below the threshold. In this way, the inlet opening 248 of the FS sensor 201 be increased or decreased depending on whether the exhaust gas flow rate is below or above the threshold, by active settings, at the position of the flow control 238 be made. Additionally or alternatively, the controller 12 the position of the flow control 238 depending on the exhaust gas flow rate. As the exhaust gas flow rate increases, the controller can 12 thus the flow control 238 closer to the first flow diverter 234 rotate, eliminating the inlet opening 248 is reduced. In this way, the flow control 238 be set in a plurality of positions based on the exhaust gas flow rate.

In one example, the controller sends 12 during operation of the FS sensor to collect soot particles, a control signal to an electrical circuit to apply a voltage to the sensor electrodes of the FS sensor to capture the charged particles on the surface of the sensor electrodes. In another example, the controller 12 during regeneration of the FS sensor, sending a control signal to a regeneration circuit to close a switch in the regeneration circuit for a period of time of threshold to apply a voltage to heaters coupled to the sensor electrodes to heat the sensor electrodes , In this way, the sensor electrodes are heated to burn soot particles deposited on the surface of the sensor electrodes. Exemplary routines are here in relation to the 3 - 5 described.

In some embodiments, the flow control 238 passively adjusted on the basis of the pressure acting on an outer side of the movable flow control plate 238 exerted by incoming exhaust gas. Here is the flow control 238 with the inner surface of the upstream pipe wall 208 be coupled via a spring joint, which is capable of axial rotation. If the exhaust gas flow rate is above the threshold, the pressure exerted by the incoming exhaust gas on the flow control may be higher and this would cause the spring joint to rotate in a first direction (eg, counterclockwise), thereby providing flow control 238 closer to the first flow diverter 234 is moved and the inlet opening 248 is reduced. In this embodiment, the amount or amount by which the flow control 238 rotates or moves depending on the spring constant of the spring joint and the pressure exerted by the incoming exhaust gas. However, when the exhaust gas flow rate falls below a threshold, the pressure exerted on the flow control by the incoming exhaust gas may be lower, causing the spring joint to rotate in a second direction opposite the first direction (eg, clockwise) the flow control 238 moved away from the first flow diverter and the inlet opening 248 is enlarged. Again, the extent or amount by which the flow control 238 rotates or moves depending on the spring constant of the spring joint and the pressure exerted by the incoming exhaust gas. In some examples, when the exhaust gas flow rate is below the threshold, the spring joint may be in its equilibrium position, thereby maximally opening the inlet port. In this example, the flow control moves passively and is not controlled by the controller.

By moving the position of the flow control based on the exhaust gas flow rate, it may be possible to adjust the inlet opening of the FS sensor so that the amount of exhaust gas entering the FS sensor and thus the rate at which particles on the FS sensor element 254 to be deposited, is almost constant (eg kept at a relatively constant level). Therefore, the flow control by operating the motor actuator 256 active or by the pressure exerted by the incoming exhaust gas flow to the flow control, are moved passively. Regardless of whether the flow control setting is active or passive, the rate of deposition of the particles on the FS sensor element is independent of the exhaust gas flow rate, thereby rendering the sensitivity of the FS sensor independent of the incoming exhaust gas flow rate. This becomes with respect to the exhaust gas flow paths within the FS sensor 201 further clarified.

The incoming exhaust gas flow 246 (also incoming exhaust gas or incoming exhaust gas) refers to the FS sensor 201 upstream Exhaust gas entering the inlet 210 of the FS sensor 201 entry. Therefore, the exhaust gas flow 246 for example, the exhaust gas exiting the DPF. Due to the presence of flow control 238 near the inlet 210 of the FS sensor 201 becomes part of the incoming exhaust gas flow 246 blocked and only a part of the incoming exhaust gas flow 246 , referred to as exhaust gas flow 247 , flows into the inlet opening 248 of the FS sensor. The exhaust gas flow 247 in the inlet opening 248 flows, for example, over the space between the unattached end of the flow control 238 and the downstream pipe wall 206 in the inlet opening 248 of the FS sensor. The exhaust gas flow 247 can be part of the incoming exhaust gas flow 246 include. On the basis of the exhaust gas flow rate of the incoming exhaust gas 246 can the flow control 238 either active via the motor actuator 256 or passively rotated over the spring joint, as already described. When the exhaust gas flow rate of the incoming exhaust gas 246 below the threshold, then the flow control 238 be adjusted to the inlet opening 248 to enlarge, as in the view 200 out 2A shown. Therefore, the setting includes the flow control 238 Moving the flow control 238 in a first direction (eg, clockwise) away from the first flow diverter 234 , whereby the inlet opening 248 is enlarged. The exhaust gas flow 247 enters through the inlet opening 248 in the FS-sensor 201 one. The first flow diverter 234 then captures a first set of particles in the exhaust stream 247 at the lower surface of the first flow diverter 234 that's the inlet 210 of the FS sensor 201 is facing. The first set of particles includes particles in the exhaust stream 247 that are larger than a threshold size. The larger particles and / or water droplets 242 that at the first flow diverter 234 can be caught, the FS sensor 201 thus over the inlet 210 leave, reducing the amount of larger particles that are on the FS sensor element 254 settle, is reduced. In this way, the FS sensor element can be protected from hitting water droplets and larger particles, and the FS sensor can be made more reliable.

The first flow diverter 234 further directs a portion of the exhaust stream ( 249 ) from the inlet opening 248 to one or more of the second flow diverter 236 and the FS sensor element 254 , The exhaust gas flow 249 can be part of the incoming exhaust gas flow 246 include (and a portion of the exhaust stream 247 ), which points in the direction of the FS sensor element 254 of the FS sensor 201 through the first flow diverter 234 is directed. For example, the first flow diverter 234 a second set of particles 244 in the exhaust stream 249 in the direction of the FS sensor element 254 where they are subsequently deposited. Therefore, the second set of particles 244 a smaller size compared to the first set of particles 242 for example, previously with the first flow diverter 234 was blocked.

When the exhaust gas flow rate of the incoming exhaust gas 246 above the threshold, then the flow control 238 be adjusted to the inlet opening 248 to zoom out, as in the view 260 out 2 B shown. Therefore, the setting includes the flow control 238 Moving the flow control 238 in a second direction (eg, counterclockwise) in the direction of the first flow diverter 234 , whereby the inlet opening 248 is reduced. The exhaust gas flow 247 enters through a restricted inlet opening 248 in the FS-sensor 201 one ( 2 B ). As for 2A explains, the first flow diverter begins 234 a first set of particles in the exhaust stream 247 at the lower surface of the first flow diverter 234 that's the inlet 210 of the FS sensor 201 is facing. As the inlet opening is reduced, the amount of exhaust gas becomes 249 in the inlet opening 248 of the FS sensor occurs, reduced.

The first flow diverter 234 also directs a portion of the exhaust stream 249 from the inlet opening 248 to one or more of the second flow diverter 236 and the FS sensor element 254 (please refer 2A and 2 B ). The exhaust gas flow 249 refers to a part of the incoming exhaust gas flow 246 (and also on a part of the exhaust gas flow 247 ), which points in the direction of the FS sensor element 254 of the FS sensor 201 through the first flow diverter 234 is directed. Therefore, the exhaust gas flow 249 who in 2A through a larger opening 248 flows, larger than the exhaust gas flow 249 be in 2 B through the limited opening 248 flows. In the two views 200 and 260 can the first flow diverter 234 however, a second set of particles 244 in the direction of the FS sensor element 254 where they are subsequently deposited. The second flow diverter 236 which is at a higher level than the detecting portion of the FS sensor element 254 is positioned, directs the second set of particles 244 further in the direction of the FS sensor element 254 , The second flow diverter 236 may further direct the exhaust flow to the sensing element 254 conduct before leaving the FS sensor 201 escapes. Therefore, the second set of particles 244 a smaller size compared to the first set of particles 242 for example, previously with the first flow diverter 234 was blocked. However, by adjusting the inlet opening of the FS sensor, the amount of exhaust gas entering the FS sensor can be adjusted to control the deposition rate of the particles on the FS sensor element 254 constant too hold. If the second set of particles 244 on the FS sensor element 254 , especially on the electrodes 220 on the sensor substrate 216 Deposited, the resistance decreases, as by the measuring device 226 in the electrical circuit 258 measured. The control 12 can be a soot load on the electrodes 220 of the FS sensor based on the resistance measured by the measuring device (like the measuring device 226 out 2A and 2 B for example). When the soot load reaches a threshold load, the electrodes can 220 of the FS sensor to clean the electrode surface of any particles deposited thereon. By monitoring the deposition rate and / or the regeneration time of the FS sensor, it is possible to diagnose leaks in the particulate filter located upstream of the FS sensor. Therefore, the second flow diverter conducts 236 also a part of the exhaust gas flow 251 through the outlet 214 of the FS sensor 201 , Thus, the exhaust gas flow 251 a part of the incoming exhaust gas 246 which is the FS sensor electrode via the outlet 214 leaves.

Thus, exhaust gas flow to an FS sensor element positioned within the FS sensor with the FS sensor positioned in an exhaust flow channel may be reduced in response to an exhaust flow rate of exhaust flow in the exhaust flow channel that is below a threshold. The exhaust gas flow to the FS sensor may also be reduced in response to the exhaust gas flow rate being above the threshold. Increasing the exhaust gas flow includes rotating a flow control disposed proximate an inlet port of the FS sensor in a first direction, and further including decreasing the exhaust gas flow rotating the flow rate control in a second direction opposite the first direction. Turning the flow control in the first direction further includes moving the flow rate control away from a first flow plate or first flow diverter located at or near the inlet port of the FS sensor, and further rotating the flow control in the second direction Moving the flow rate controller toward the first flow plate of the FS sensor assembly. In one example, the rotation of the flow control may be controlled by a controller and a motor actuator that may be actuated by the controller to rotate the joint that is coupled to the flow controller. In other examples, the rotation of the flow control may be passive, without any signals from the controller. Here, the pressure exerted by the incoming exhaust gas may rotate the flow control coupled to the FS sensor via, for example, spring joints. The FS sensor may further include a second flow plate or second flow diverter located proximate an outlet of the FS sensor, and the second flow plate may be spaced from the first flow plate. The function of the first flow diverter may include one or more of trapping a first set of particulates in the exhaust flow at the inlet port of the FS sensor and directing a second set of particulates in the exhaust flow from the inlet toward an FS sensor element, which may be at or in the vicinity of the second flow plate to facilitate the deposition of the second set of particles on the FS sensor element, wherein the first set of particles is larger than the second set of particles. When a deposition rate of the second set of particles from the FS sensor element exceeds a threshold rate, a leak may be displayed in a particulate filter disposed upstream of the FS sensor. Here, the first flow plate further directs the exhaust gas flow in the direction of the second flow plate and wherein the second flow plate further diverts the exhaust gas flow in the direction of the outlet of the FS sensor.

2C shows a schematic view 265 an exemplary embodiment of the FS sensor 201 , The second embodiment is the first embodiment described above with respect to FIGS 2A and 2 B essentially similar. The FS sensor 201 can the flow rate control 238 included, which is adjusted based on the exhaust gas flow rate within the exhaust passage. For example, when the exhaust gas flow rate is higher than a threshold rate, the flow rate control becomes 238 in the direction of the flow diverter 234 rotated and thus the inlet opening is reduced and the flow of exhaust FS in the FS sensor 201 through the inlet opening 248 is reduced. Larger particles and water droplets 242 be through the flow diverter 234 blocked. Instead of using only a single second flow diverter (such as the one in FIGS 2A and 2 B shown second flow diverter 236 ), it is possible to use a variety of flow plates 266 , as in 2C shown to use the exhaust within the FS sensor 201 in the direction of the FS sensor element 254 to move. In particular, exhaust gas is produced by means of the plurality of flow plates 266 over the detection electrodes 220 of the FS sensor element 254 distributed as described below.

The variety of flow plates 266 includes a series of parallel flow plates that run along the upstream wall 208 is arranged and extending along a length L within the protective tube 250 of the FS sensor extends. A first end of each of the multitude of flow plates 266 is with an inner surface of the upstream wall 208 coupled and a second opposite end of each of the plurality of flow plates 266 is from the FS sensor element 254 spaced. Here each flow plate encloses 268 the variety of flow plates 266 an angle α with respect to the horizontal X-axis. In one example, the angle α may be 30 °. In other examples, the angle α may be 45 °. For example, the angle α may be within a range given by 0 <α <60 ° and 10 <α <50 ° in a more specific example. In an alternative example, the plurality of flow plates 266 be positioned parallel to the X-axis and thus parallel to the direction of the exhaust gas flow (indicated by the arrow 246 ) within the exhaust duct 235 ,

In the example off 2C is every flow plate 268 the variety of flow plates 266 parallel to the others, thus each flow plate is angled at an angle α with respect to the horizontal X axis. In addition, each flow plate is spaced by a space from adjacent flow plates. Seven non-limiting examples of flow slats 268 are shown, with each flow plate 268 with an inner surface of the upstream wall 208 is coupled. Each flow plate 268 can have an open area (or opening) 270 Include a closed area 272 is sibling. Here can be the size of any open area 270 and closed area 272 over adjacent flow plates 268 vary, as in the 2D and 2E shown.

In relation to 2D is a cross-sectional view 280 an upper (for example, the uppermost) flow plate of the plurality of flow plates 266 shown taken along an axis AA '. 2E shows a cross-sectional view 285 a flow plate directly under the top plate taken along an axis BB '. Here, the axis AA 'is parallel to the axis BB'; both of which are angled at an angle α with respect to the horizontal X-axis. The topmost flow plate included a semicircular disk 282 of diameter D. Here is the semicircular area 272 the disc 282 a closed area, which implies that exhaust gas may not be able to pass through the top plate of the multitude of flow plates 266 to stream. The curved section of the disc 268 is with the curved inner surface of the upstream wall 208 coupled. In some examples, the curvature of the disc 282 smaller than the curvature of the protective tube of the FS sensor 201 , Similar to the disc 282 in 2D is the in 2D shown flow plate a semicircular disc 286 of diameter D. The disc 286 includes both an open area 270 as well as a closed area 272 , Here is the open area 270 a segment of the arrow or the length L1. Thus, the width W of the closed area 272 be given by (D / 2 - L1).

wobei Ao die Fläche des offenen Bereichs 270 ist, D der Durchmesser der halbkreisförmigen Scheibe ist und θ der Mittelwinkel im Bogenmaß ist. The topmost flow plate of the plurality of flow plates may be considered a solid semicircular disk 282 of the diameter D are produced. The subsequent flow plates may also be made from semi-circular discs, but with cut-out portions to allow exhaust gas to flow toward the electrodes of the sensor element. For example, the flow plate may be just below the topmost flow plate of a solid disk of diameter D (similar to disk 282 ), but with a hollow segment of length L1. Here the hollowed-out segment forms the open area 270 the flow plate. By starting with a solid plate of diameter D, it is possible to increase the area of the area excavated or removed from the solid disk by the size of the open area 270 to increase. This, in turn, reduces the area of the closed area 272 to lead. In a similar manner, when the area of the area hollowed out from the first slice is reduced, this becomes the size of the open area 270 zoom out and the area of the closed area 272 enlarge. As an example, the fixed disc includes 286 the open area 270 which is available in the shape of a segment. Mathematically, this is the open area or the opening 270 hollowed segment given by equation (1):

where Ao is the area of the open area 270 D is the diameter of the semicircular disk and θ is the center angle in radians.

The arrow (or height) L1 of the segment may be given by equation (2): L1 = D / 2 (1 - cos θ / 2) (2)

The top plate of the variety of flow plates 266 can only use the closed area 272 include and can not contain an open area. The flow plate directly under the topmost flow plate of the plurality of flow plates 266 may include an open area of the area Ao as described by equation (1). Thus, the area of the closed area, Ac, can be obtained by subtracting the area of the open area from the area A of the fixed disk of the diameter D, and can be given by the equation (3):

Subsequent flow plates of the plurality of flow plates 266 can be made by increasing the area of the open area Ac cut from the solid disk. For example, 2Ac may be cut out of the third plate from the uppermost of the plurality of flow plates, and so on. Therefore, the last of the lowermost flow plates of the plurality of flow plates becomes the largest open area 270 and the smallest closed area 272 exhibit. In this way, subsequent flow plates of the plurality of flow plates 266 be educated. It is understood that the diameter D of each flow plate of the plurality of flow plates 266 can be the same for all plates. Therefore, this ensures that the distance of a straight edge of each bezel disc uniformly from the FS sensor element 254 is spaced. Here are the flow plates semicircular discs. However, various geometries and shapes of the flow plates may be used without departing from the scope of the invention. Exemplary shapes include rectangular, square, triangular, and the like.

Returning to 2C can any of the flow plates, which in terms of the 2D and 2E are described with the inner surface of the upstream wall 208 of the protective tube 250 be coupled. Here, the curved portion of the semicircular flow plate with the inner surface of the upstream wall 208 be coupled (eg the same side with which the flow control 238 coupled), and the straight edge or the straight portion of the semicircular plate can toward the inside of the FS sensor protective tube 250 point. In particular, the straight edge of the semicircular plate may be closer to the FS sensor element 254 be positioned while the curved portion of the semicircular plate farther away from FS sensor element 254 can be located. In the view 260 has the variety of flow plates 266 a rectangular cross-section, it is understood, however, that each flow plate 268 the variety of flow plates 266 a semicircular disc is how in relation to the 2D and 2E is described.

The variety of flow plates 266 is by arranging a series of flow plates 268 between the upper surface 212 and the inlet opening 248 of the FS sensor 201 educated. Here, the topmost flow plate of the plurality of flow plates 266 closer to the upper surface 212 and the bottom most flow plate of the plurality of flow plates 266 can get closer to the inlet opening 248 are located. Therefore, a distance between the uppermost flow plate and the lower most flow plate may be based on a length of the detection portion (or a distance to which the interdigital electrodes 220 on the surface of the FS sensor substrate 216 extend). As a non-limiting example, there are seven flow plates 268 with a distance d (or space d in between) over the length or distance L2. In an exemplary configuration in which the thickness w of each of the flow plates 268 is equal, the distance L2 may be about 7 * (d + w). The space d between adjacent flow plates 268 the variety of flow plates 266 may not contain any components. The space d and the distance L1 can be set on the basis of a distance to which the interdigital electrodes 220 on the substrate 216 of the FS sensor element 254 extend.

As described above, except for the top plate of the plurality of flow plates 266 all other flow plates of the plurality of flow plates 266 an open area 270 and a closed area 272 , The first flow diverter 234 captures a first set of particles in the exhaust stream 247 , The first set of particles includes particles in the exhaust stream 247 that are larger than a threshold size. The larger particles and / or water droplets 242 that at the first flow diverter 234 can be caught, the FS sensor 201 thus over the inlet 210 leave, reducing the amount of larger particles that are on the FS sensor element 254 settle, is reduced. Additionally, a second set of particles 274 (which is smaller than the first set of particles) to be able to pass through the opening 248 escapes. The second set of particles 274 can through the closed area 272 the variety of flow plates 266 be blocked. In this way, the FS sensor element can be protected from impacting water droplets and larger particles, and the FS sensor can be made more reliable.

Each flow plate 268 the variety of flow plates 266 can exhaust that enters the thermowell 250 through the inlet opening 248 flows, dividing into a first part and a second part. The first part of the exhaust gas can pass through the open area 270 flow the flow plate into the space d between adjacent flow plates as indicated by arrow 276 shown. The second portion of the exhaust gas may flow through the open area of a first flow plate toward the open area of an adjacent flow plate disposed, for example, immediately above the first flow plate. Therefore, exhaust gas at each of the flow plates of the plurality of flow plates 266 be divided into the first part and the second part. Thus, the plurality of flow plates 266 divide the incoming exhaust into multiple flow paths or streams. In the example of the seven flow plates, the incoming exhaust gas can be divided into six streams, all in the direction of the electrodes 220 be directed. Exhaust gas can not flow through the topmost flow plate because it has no open area. If n flow plates are present, the exhaust gas can be divided into (n-1) streams. Therefore, the first part may include a third set of particles. Here, the third set of particles (eg, soot particles) may be smaller compared to each of the first and second sets of particles. The third set of particles can be via electrodes 220 of the FS sensor element 254 be caught. In this way, soot particles in the exhaust gas can be evenly distributed over the sensor electrodes. Once the third set of particulate matter is deposited on the sensor electrodes, the exhaust gas flows out of the FS sensor 201 through the outlet 214 which is near the FS sensor element 254 is positioned. The control 12 can control the electrical circuit, as with respect to the 2A and 2 B Explained to the third set of particles, located above the electrodes 220 has accumulated, and a soot load on the FS sensor 201 based on the change in current / resistance measured across the electrodes. Therefore, a leak in the particulate filter upstream of the FS sensor may be indicated when a deposition rate of the third set of particulate matter on the FS sensing element exceeds a threshold rate.

In the 2C shown variety of flow plates 266 includes parallel flow plates with a uniform spacing between them. Another exemplary embodiment of the plurality of flow plates is in the schematic view 290 out 2F shown. Here can be a variety of flow plates 292 in a similar way to the variety of flow plates 266 out 2C manufactured and positioned. The variety of flow plates 292 can flow plates 294 include not all parallel to each other. In the view 290 , are eight non-limiting flow plates 294 shown. Two of the lowermost plates are shown parallel to each other. The remaining six flow plates 294 are at an angle β with respect to each other. Various combinations of angled and parallel flow plates 294 are possible. In an exemplary embodiment, half of the flow plates are parallel and the other half of the flow plates may be at an angle with respect to each other. In another embodiment, all of the flow plates may be angled. For the angled plates, the angle β need not be the same for different pairs of adjacent flow plates.

Similar to any flow plate 268 out 2C includes each flow plate 294 out 2F an open area 296 and a closed area 297 , A length of the closed area 297 and the open area 296 can for each flow plate 294 be different. With every pair of flow plates 293 The lower flow plate includes a smaller closed area 296 as the upper flow plate. Likewise, the lower flow plate includes the pair of flow plates 293 a larger closed area 297 as the top plate of the pair of flow plates. In this way, the closed areas of the pair of flow plates 293 include an overlay which involves catching the second set of particles 274 the lower plate continues to support and the exhaust through the open area 296 in the direction of the electrodes 220 of the FS sensor element 254 passes. Each pair of flow plates of the plurality of flow plates 292 can be formed in a similar manner, superimposed on closed areas. Exhaust gas can thus by the variety of flow plates 292 be directed. In particular, the third set of particles may be in the direction of the electrodes 220 (as indicated by the arrow 299 displayed), wherein the third set of particles in the exhaust gas can be evenly distributed over the sensor electrodes. Once the third set of particulate matter is deposited on the sensor electrodes, the exhaust gas flows out of the FS sensor 201 through the outlet 214 which is near the FS sensor element 254 is positioned as above with respect to 2A - 2C described.

In this way, soot particles can be evenly distributed over the electrodes of the FS sensor. The FS sensor 201 through the outlet 214 which is near the FS sensor element 254 is positioned. The control 12 can control the electrical circuit, as with respect to the 2A and 2 B Explained to the third set of particles, located above the electrodes 220 has accumulated, and a soot load on the FS sensor 201 based on the change in current / resistance measured across the electrodes. Therefore, a leak in the particulate filter upstream of the FS sensor may be indicated when a deposition rate of the third set of particulate matter on the FS sensing element exceeds a threshold rate.

The 2A - 2F show exemplary configurations with a relative arrangement of the various components. When they are shown touching directly or directly At least in one example, such elements may each be referred to as directly touching or directly coupled, respectively. Similarly, elements that are shown abutting one another or adjacent to one another may, at least in one example, be adjacent to each other or adjacent to each other. As an example, components that are in face sharing contact with each other may be referred to as face sharing contact. As another example, elements that are positioned apart from each other, with only one space therebetween and no other components, may be referred to as such, at least in one example.

The controller can be a procedure 300 , which in relation to 3 for controlling the FS sensor inlet opening based on the exhaust gas flow rate. Instructions for performing the procedure 300 and the other methods contained herein may be controlled by a controller (such as those described in U.S. Pat 1 and the 2A - 2 B shown control 12 ) on the basis of instructions stored in a memory of the controller and in connection with signals received from sensors of the engine system, such as those described above with reference to FIG 1 and the 2A and 2 B described sensors. The controller may employ engine actuators of the engine system to adjust engine operation in accordance with the methods described below.

In relation to 3 is a procedure 300 for adjusting the inlet port of an FS sensor (such as an FS sensor 201 from the 1 . 2A and 2 B ) based on an exhaust gas flow rate. In particular, the degree of opening of the inlet to the FS sensor positioned in an exhaust stream may be increased or decreased if the exhaust flow rate upstream of the particulate matter sensor is correspondingly higher or lower than a threshold.

at 302 includes the procedure 300 Determining and / or estimating engine operating conditions. Specific engine operating conditions may include, for example, engine speed, exhaust flow rate, engine temperature, exhaust gas exhaust gas temperature, exhaust gas temperature, duration (or distance) since a last regeneration of the DPF, FS load on the FS sensor, boost level, ambient conditions such as barometric pressure and ambient temperature , etc. include.

The exhaust passage of the engine may include one or more sensors that may be upstream and / or downstream of the DPF to determine an exhaust gas flow rate. For example, the engine may include flow meters for exhaust mass flow measurement and for determining the exhaust gas flow rate at the inlet of the FS sensor. In some examples, the incoming exhaust flow rate at the inlet of the FS sensor may be determined based on a suction exhaust gas flow rate. In some examples, the exhaust flow rate through the exhaust passage in which the FS sensor is installed may thus be estimated based on changing engine sensors and / or operating conditions.

at 304 the method includes determining if the exhaust gas flow rate is above a threshold. In one example, the threshold may be a threshold rate based on a desired deposition rate of the particulate matter on the particulate matter sensor element. In other examples, the threshold may be a threshold regeneration time of the FS sensor. When the incoming exhaust gas flow rate is high, the time to reach the regeneration threshold of the FS sensor is typically lower than when the exhaust gas flow rate is low.

If the exhaust gas flow rate is lower than the threshold, then the process goes 300 to 306 where the amount of opening of the FS sensor inlet is increased. As above with reference to the 2A - 2 B For example, the FS sensor may include a first flow diverter and a flow controller (such as those shown in FIGS 2A - 2 B shown flow control 238 ) positioned at the inlet, wherein an end of the flow rate is positioned spaced from the first flow diverter to create a gap at the inlet. Therefore, increasing the extent of opening at 308 Enlarge the gap between the flow diverter and the flow control by rotating the flow control in a first direction away from the first flow diverter. Turning the flow control in the first direction includes sending signals to the motor actuator for rotating the joint that couples the flow control to the protective tube in a first direction for a threshold amount. In one example, the flow control may be rotated 30 ° counterclockwise about a center axis of the FS sensor. Increasing the gap between the flow control and the first flow diverter allows more exhaust gas to flow into the FS sensor, thereby increasing the amount of particulates flowing into the FS sensor, which, in turn, increases the deposition rate of the particulate matter on the FS sensor. However, if the exhaust gas flow rate is higher than the threshold, then the method goes 300 to 310 over where the extent of opening of the inlet is reduced. Therefore, reducing the extent of opening involves 312 Decreasing the gap between the flow diverter and the flow control by rotating the flow control in a second direction opposite the first direction and away from the first flow diverter. Turning the flow control in the second direction includes sending signals to the motor actuator for rotating the joint that couples the flow control to the protective tube in the second direction for a threshold amount. In one example, the flow control may be rotated 30 ° counterclockwise about a center axis of the FS sensor. Reducing the gap between the flow control and the first flow diverter restricts the exhaust gas flowing into the FS sensor, thereby reducing the amount of particulates and thereby reducing, for example, the deposition rate of the particulates on the FS sensor.

In one example, the opening is enlarged (at 306 ) or reduced (at 310 ) by rotating the flow control by a threshold amount, the threshold amount being a fixed amount that is further based on the exhaust gas flow rate. For example, if the exhaust flow rate is above the threshold, then the flow control may be rotated 30 degrees in the second direction (at 312 However, if the exhaust gas is below the threshold, the flow control can be rotated by 30 ° in the first direction (at 308 ). In other examples, the flow rate control may be rotated by a threshold amount, wherein the threshold amount is variable and further based on the exhaust gas flow rate. If at 312 For example, if the exhaust gas flow rate is above the threshold by a certain amount, the amount of opening is reduced by a larger amount than the amount by which the exhaust gas flow rate that exceeds the threshold value increases. Equally, if at 308 If the exhaust gas flow rate is below the threshold by a certain amount, the amount of opening is increased by a larger amount than the amount by which the exhaust gas flow rate lower than the threshold value decreases. In other words, the extent of opening may depend on the amount. which the exhaust gas flow rate differs from the threshold.

Once the inlet opening has been adjusted based on the exhaust gas flow rate (either at 306 enlarged or at 310 reduced), goes the procedure 300 to 314 above. at 314 For example, particles moving in the exhaust stream may be separated from the exhaust stream flowing into the FS sensor sensing element based on the magnitude. For example, a first set of particles (eg, larger particles and / or water droplets) may be present in a first flow diverter (such as the one shown in FIGS 2A - 2 B shown first flow diverter 234 ), thereby allowing only second and third sets of particulates in the exhaust gas to enter (eg, flow through) the FS sensor inlet port. Here, the first set of particles may be larger than each of the second and third sets of particles. at 318 For example, the second set of particles may be blocked in the plurality of flow diversifiers. In one example, the plurality of flow diverters or flow plates may include parallel flow plates coupled to an inner surface of an upstream wall of the FS sensor (such as the upstream wall 208 from the 2A - 2C and 2F ). In another example, the plurality of flow plates may include one or more angled and parallel flow plates. In both examples, each flow plate may include an open area and a closed area. Exhaust gas may flow through the open area toward a space between adjacent flow plates. In addition, the second set of particles may be blocked at the closed area. The third set of particles can be directed through the open area into the space between flow plates and then toward the FS sensor element. The third set of particles containing smaller soot particles may then be included 320 directed in the direction of the FS sensor element (as in the 2C and 2F described) and then at 322 on the FS sensor element deposit (such as in the 2C - 2F shown sensor element 254 ). Next, the method involves 324 Flowing the exhaust gas out of the FS sensor through outlets positioned near the FS sensor element. In an exemplary configuration, two circular outlets may be formed on two opposing surfaces of the FS sensor and may be positioned closer to the FS sensor element than to the inlet opening. Exhaust gas may flow upward (against gravity) to flow toward the outlet from the FS sensor element and then out through the outlets of the FS sensor.

Next, the method involves 326 Determine if the regeneration conditions of the FS sensor are met. In particular, if the FS load on the FS sensor element is above a threshold, or if a resistance of the FS sensor drops to a threshold resistance, the conditions for regeneration of the FS sensor may be considered satisfied and the FS sensor may be regenerated require to allow further FS detection. If the regeneration conditions of the FS sensor are met, then the procedure goes 300 to 330 over where the FS sensor as in procedure 400 out 4 is regenerated described. However, if the regeneration conditions of the FS sensor are not are fulfilled when they are at 326 be checked, then go the procedure 300 to 328 across where the FS sensor continues to collect FS on the FS sensor. Therefore, any FS that is not deposited on the FS sensor will slip out of the FS sensor via the outlet of the FS sensor.

The method described above 300 may be performed by a controller to maintain the deposition rate of the FS sensor by adjusting the inlet opening of the FS sensor. In other embodiments, where the FS sensor includes a spring joint for coupling flow control to the protective tube of the FS sensor, adjusting the FS sensor inlet port may be passively achieved without intervention by the controller. Based on the pressure exerted by the incoming exhaust, the spring joint may rotate the flow control here and thereby control the extent of opening of the inlet of the FS sensor.

Thus, an exemplary method includes adjusting an amount of opening of an inlet to a particulate matter sensor positioned in an exhaust stream in response to an exhaust gas flow rate upstream of the particulate matter sensor, and flowing exhaust gas past a plurality of flow plates toward a particulate matter sensor element positioned near the multitude of flow plates. The adjusting includes increasing the amount of opening of the inlet when the exhaust gas flow rate falls below a threshold rate and further including decreasing the extent of opening of the inlet when the exhaust gas flow rate exceeds the threshold rate. The particulate matter sensor includes a flow diverter and flow control positioned at the inlet, wherein the flow control and the flow diverter are coupled to different opposing surfaces of the FS sensor such that a gap is formed between the flow control and the flow diverter at the inlet , Increasing the extent of opening includes increasing the gap between the flow diverter and the flow control by rotating the flow control in a first direction away from the flow diverter and reducing the extent of opening comprises reducing the gap between the flow diverter and the flow control by rotating the flow control in FIG a second direction opposite the first direction toward the flow diverter. The plurality of flow plates further includes one or more of parallel plates and angled plates separated by a space and positioned proximate to an outlet of the particulate matter sensor, wherein the plurality of flow plates are separated by a distance from the flow diverter. The plurality of flow plates directs the exhaust gas, which comes through the gap formed at the inlet between the flow control and the flow diverter, into the space formed between the plurality of flow plates, toward the fine dust sensor element which is in the vicinity of Outlet of the particulate matter sensor is positioned.

Thus, an exemplary method for a particulate matter (FS) sensor includes increasing an exhaust flow into an FS sensor element positioned within the FS sensor, wherein the FS sensor is positioned in an exhaust flow channel in response to an exhaust flow rate the exhaust gas flow in the exhaust gas flow passage is below a threshold, decreasing the exhaust gas flow into the FS sensor element in response to the exhaust gas flow rate being above the threshold, and flowing the exhaust gas between a plurality of flow diverters toward the FS sensor element which is proximate the plurality of Strömungsumleitern is positioned. Additionally or alternatively, increasing the exhaust gas flow may include rotating a flow rate controller disposed proximate an inlet port of the FS sensor in a first direction, and decreasing the exhaust gas flow rotating the flow rate control in a second direction opposite to the first direction is included. Additionally or alternatively, rotating the flow control in the first direction may further include moving the flow rate control away from a flow plate located at or near the inlet port of the FS sensor, and further rotating the flow control in the second direction may include flow rate control toward the first flow plate of the FS sensor assembly. Additionally or alternatively, the plurality of flow diverters may be separated by a space, and wherein each of the plurality of flow diverters includes a plate having an opening allowing a first portion of the exhaust gas to pass from the space into the space between the plurality of flow diverters Direction of the sensor element to flow, and a second part of the exhaust gas to flow toward the opening of an adjacent flow conductor, wherein the openings of adjacent flow diverter may have different sizes. Additionally or alternatively, the plurality of flow diverters may be parallel to one another and wherein the space between adjacent flow diverters can be uniform. Additionally or alternatively, the plurality of flow diverters may be angled plates and the space between adjacent flow diverters may be non-uniform. Additionally or alternatively, the method may trap a first set of particulate matter in the exhaust stream at the inlet port of the FS sensor, trapping a second set of particulate matter at the plurality of flow redirectors, wherein the second set of particulates is smaller than the first set of particulates, Directing a third set of particles in the exhaust stream from the space between adjacent flow diverters toward an FS sensor element positioned at or near the plurality of flow diverters to facilitate deposition of the third set of particles from the FS sensor element the third set of particles is smaller than each of the first set of particles and the second set of particles, and includes indicating a leak in a particulate filter upstream of the FS sensor when a deposition rate of the third set of particulates on the FS Sensor element exceeds a threshold rate.

Now, in terms of 4 a procedure 400 to regenerate the FS sensor (such as an in 1 shown FS-sensor 106 and / or the FS sensor 201 from the 2A -F). In particular, if the soot load on the FS sensor is above the threshold, or if a temperature set resistance of the FS sensor drops to a threshold resistance, the conditions for FS sensor regeneration may be satisfied and the FS sensor may require regeneration to allow further FS detection. at 402 Regeneration of the FS sensor can be initiated and the FS sensor can be activated by heating up the sensor 404 be regenerated. The FS sensor can be heated by operating a heating element until the soot load of the sensor is sufficiently reduced by oxidation of the carbon particles between the electrodes. The regeneration of the FS sensor is typically controlled using timings and timing may be included 402 be set to a period of the length of a threshold. Alternatively, the sensor regeneration may be controlled by the use of a temperature measurement of the sensor tip or by the control of the energy provided to the heater, or any or all of them. If a timer is used to regenerate the FS sensor, the procedure includes 400 Check if the period of time is equal to the length of the threshold 406 has expired. If the time period with the length of the threshold has not expired (for example, "NO" at 406 ), so goes the procedure 400 to 408 over where the regeneration circuit can remain on to continue regeneration, and the process ends. When the threshold time period has expired (for example, YES at 406 ), so goes the procedure 400 to 410 over where the regeneration of the FS sensor stops and the electrical circuit at 412 can be switched off. Furthermore, the sensor electrodes can be cooled to the exhaust gas temperature, for example. The procedure 400 go to 414 where the load of the FS sensor and the progress of the regeneration can be updated and stored in a memory. For example, a frequency of regeneration of the FS sensor and / or an average time between sensor regenerations may be updated and the method ends.

The exhaust passage of the engine may include one or more FS sensors that may be upstream and / or downstream of the DPF to determine a soot load of the DPF. If the FS sensor is placed upstream of the DPF, a soot load on the sensor may be dissipated based on the change in resistance due to soot build-up at the plurality of electrodes of the FS sensor. For example, the soot load determined in this way can be used to update the soot load on the DPF. If the soot load on the DPF is higher than a DPF regeneration threshold, then the controller may set the engine operating parameters to regeneration of the DPF. In particular, in response to the conditions for the regeneration of the filter being met, a temperature of the filter (or near the filter) may be increased sufficiently to burn deposited soot. This may include operating a heater coupled to the DPF or increasing the temperature of the engine exhaust gas (eg, by rich operation) flowing into the DPF.

Referring again to 5 is an exemplary process 500 to diagnose the DPF function based on the regeneration time of the FS sensor. at 502 For example, the controller may calculate the regeneration time for the FS sensor, t (i) _regen, which is the time measured from the end of the previous regeneration to the beginning of the current regeneration of the FS sensor, by calibration , at 504 t (i) _regen is compared to t (i-1) _regen, which is the previously calibrated regeneration time of the FS sensor. From this it can be deduced that the soot sensor can switch several times through the regeneration to create a diagnosis for the DPF. If t (i) _regen is less than half the value of t (i-1) region, then 508 indicated that the DPF is leaking, and a signal relating to the degradation of the DPF is initiated. Alternatively, or in addition to the above-mentioned method, using other parameters such as exhaust gas temperature, engine speed / load, deposition rate of the particles on the sensor electrodes, etc., a diagnosis for the DPF are created. In one example, if the deposition rate of the soot particles on the sensor electrodes exceeds a threshold rate, then a leak in the DPF may be indicated. The impairment signal may be initiated, for example, by a fault indicator light or diagnostic code. In addition, the procedure includes 500 adjusting engine operation based on the indication of leaks in the DPF 510 , Adjusting engine operation may include, for example, limiting engine speed 512 include. In one example, engine performance and torque may be reduced in response to detecting leaks in the DPF. Reducing engine horsepower and torque can reduce the amount of FS emissions in the exhaust. For example, adjusting engine operation may reduce reducing the fuel injected into a diesel engine under heavy load conditions, thereby reducing torque. Additionally or alternatively, in response to the detection of leaks in the DPF, EGR usage may be reduced. Additionally or alternatively, an engine warning sign appears on the dashboard to indicate the maximum distance that the vehicle can still drive before service control of the DPF.

A current regeneration time of less than half of the previous regeneration time may indicate that the time that the electrical circuit has to reach the R_regen threshold is much shorter and the regeneration frequency is thus higher. A higher regeneration frequency in the FS sensor may indicate that the effluent exhaust contains a higher amount of particulate matter than was detected with a normally functioning DPF. Accordingly, if the change in regeneration time in the soot sensor reaches a threshold t_regen, where the actual regeneration time of the FS sensor is less than half the previous regeneration time, degradation or leakage of the DPF, for example via an indication to a vehicle operator and / or by setting a flag stored on a non-volatile memory coupled to the processor that may be sent to the diagnostic tool coupled to the processor. If the change in the regeneration time of the soot sensor does not reach the threshold t_regen, then 506 no leakage of DPF displayed. In this way, leaks in a particulate filter arranged upstream of the particulate matter sensor can be detected on the basis of a speed of deposition of the particles on the electrodes of the particulate matter sensor.

In relation to 6 shows the diagram 600 Now, an exemplary relationship between an exhaust flow rate, an FS sensor inlet port and an FS load on an FS sensor. The first course 602 from 600 Figure 11 shows the exhaust gas flow rate as determined by a flow rate sensor positioned upstream of the FS sensor. The second course 604 FIG. 12 shows the FS sensor inlet opening as determined by rotation of a flow control positioned near an inlet of the FS sensor, as in FIGS 2A and 2 B described. The third course 606 shows the FS load on the FS sensor. The dashed line 612 indicates the FS regeneration threshold, while the dashed line indicates 614 indicates the Lower Threshold Lower_Thr indicating that the FS sensor electrodes are clean as in 4 described. The dashed lines 608 and 610 show a threshold exhaust gas rate and a threshold inlet opening, respectively. For each plot, time is plotted along the x-axis (horizontal), while the values of each corresponding parameter are plotted along the y-axis (vertical).

At time t0, the FS sensor is relatively clean (progression 606 ), where the low FS load is below Lower_Thr (line 614 ), indicating that the FS sensor has recently been cleaned. The exhaust gas flow rate (course 602 ) is above the threshold exhaust gas rate (line 608 ). When the exhaust gas rate is above the threshold, the FS sensor inlet port may be adjusted by adjusting a movable plate (eg, flow control 238 in the 2A and 2 B ) are set in an end position between a first (closed) position and a second (open) position. Therefore, the end position may be closer to the first position than the second position. Here, the movable plate can be moved in a first direction (for example, counterclockwise) to a first flow diverter near an inlet of the FS, by operating a motor to rotate a joint that couples the movable plate to the FS sensor. Sensors are adjusted. The technical effect of setting the FS sensor inlet opening to the end position, which is closer to the first closed position, is that the clearance between the movable plate and the first flow diverter is reduced, thereby reducing the amount of FS contained in the FS Sensor enters and then settles on the FS sensor electrode settles is reduced. In this way, the deposition rate of the FS sensor can be maintained at a desired level. Here shows the rise of the line 606 the deposition rate of the FS on the FS sensor electrode.

Between t0 and t1 the exhaust gas flow (course 602 ) further above the threshold exhaust gas rate ( line 608 ), thus the FS sensor inlet opening remains closer to the first closed position. During the time between t0 and t1, the FS sensor continues to collect particles at a constant rate, indicated by line 606 ,

At t1, the FS load on the FS sensor reaches the regeneration threshold (dashed line 612 ). During the time between t1 and t2, the FS sensor can be regenerated. A controller may send instructions for sending a regeneration signal to a regeneration circuit in response to the FS level data. Regenerating the FS sensor includes, for example, operating the regeneration portion of the electrical circuit for a threshold time and / or a threshold duration, as in FIG 4 to burn the FS deposited between the electrodes of the FS sensor.

At t2, the FS sensor is relatively clean, due to a lower FS load (progression 606 ) is shown. At time t2, the exhaust gas flow rate (curve 602 ) but below the threshold rate (line 608 ). Between t2 and t3, when the exhaust gas rate is below the threshold, the FS sensor inlet port may be adjusted by adjusting a movable plate (eg, flow control 238 in the 2A and 2 B ) to an end position that is closer to the second position than the open position (trace 604 ). Here, the movable plate may be moved in a second direction (for example, clockwise) away from the first flow diverter near the inlet of the FS sensor by actuating a motor for rotating a joint that couples the movable plate to the FS sensor be set. The technical effect of adjusting the FS sensor inlet opening to the end position, which is closer to the second open position, is that the gap between the movable plate and the first flow diverter is increased, thereby increasing the amount of FS contained in the FS Sensor enters and then settles on the FS sensor electrode is increased. In this way, the deposition rate of the FS sensor can be kept at the desired level, due to the increase in the line 606 is shown. Hence, the rise of the line 606 between t2 and t4 the rise of the line 606 similar between t0 and t1. In this way, by adjusting the opening of the intake based on the exhaust gas flow rate, the FS sensor load can be maintained at a constant rate.

Between t3 and t4, the exhaust gas flow rate increases (course 602 ) above the threshold rate (line 608 ) at. By setting the FS sensor inlet opening to an end position that is closer to a first closed position as discussed above, the FS sensor load is maintained at the desired rate (slope of the line 606 ). As the exhaust flow increases above the threshold between t4 and t5, the FS sensor inlet port may similarly be adjusted to an end position that is closer to the second open position. By actively adjusting the opening of the inlet based on the exhaust gas flow rate, the FS sensor load can be maintained at the desired level. In this way, the sensitivity of the FS sensor can become independent of the exhaust gas flow rate.

The FS load (history 606 ) reaches again at t5 the regeneration threshold (dashed line 612 ). Thus, the FS sensor can be regenerated between t5 and t6, as explained above. At t6, the FS sensor is relatively clean. In addition, the FS sensor inlet port is set to an end position that is closer to the second open position when the exhaust gas flow (outflow 602 ) above the threshold (line 608 ) remains. Regardless of actively adjusting the FS sensor inlet port, the FS load on the FS sensor increases 606 ), which indicates that the deposition rate of the particles on the FS sensor is higher than the desired deposition rate, indicating that the DPF located upstream of the FS sensor is leaking. In response to the actual deposition rate of the particles on the FS sensor, which increases above the desired deposition rate of the particles on the FS sensor, thus DPF leaks can be determined and a diagnostic code can be set. For example, a MIL can be set indicating that the DPF needs to be replaced. Due to the fact that the FS sensor is independent of the exhaust gas rate, the leakage of the DPF can be detected early, thereby reducing the likelihood of operating the engine with a leaking particulate filter and thus reducing soot particle emission in the exhaust gas.

In this way, by adjusting the intake port based on the exhaust gas flow rate, the FS sensor load can be maintained at a constant rate and the dependence of the sensitivity of the FS sensor on the exhaust gas flow rate can be further reduced. Thus, the technical effect of increasing the FS sensor inlet when the exhaust gas flow rate falls below the threshold and decreasing the opening as the exhaust gas flow rate increases above the threshold is that the deposition rate of the particles on the FS sensor remains nearly constant. The sensitivity of the FS sensor is independent of the incoming exhaust gas flow rate, which makes measuring the FS leaving the DPF more accurate and reliable. Thus, leaks or deterioration of the DPF can be more efficiently and effectively recognized.

The systems and methods described above also provide a method of detecting particulate matter in an exhaust system, the method comprising: adjusting an amount of opening of an inlet to a particulate matter sensor positioned in an exhaust stream in response to a particulate matter sensor upstream Exhaust gas flow rate of the exhaust gas flow, and flowing exhaust gas past a plurality of flow plates in the direction of a particulate matter sensor element, which is positioned in the vicinity of the plurality of flow plates. In a first example of the method, the method may additionally or alternatively include adjusting to include increasing the amount of opening of the inlet when the exhaust flow rate falls below a threshold rate, and further decreasing the amount of opening of the inlet when the exhaust flow rate is the threshold rate exceeds. A second example of the method optionally includes the first example and further includes the particulate matter sensor including a flow diverter and a flow controller positioned at the inlet, the flow controller and the flow diverter coupled to different opposing surfaces of the FS sensor, such that a gap is formed between the flow control and the flow diverter at the inlet. A third example of the method optionally includes one or more of the first and second examples and further includes increasing the extent of opening to increase the gap between the flow diverter and the flow control by rotating the flow control in a first direction away from the flow diverter. A fourth example of the method optionally includes one or more of the first to third examples, and further includes reducing the amount of opening decreasing the gap between the flow diverter and the flow control by rotating the flow control in a second direction opposite to the first direction , towards the flow diverter. A fifth example of the method optionally includes one or more of the first to fourth examples, and further includes the plurality of flow plates comprising one or more of parallel plates and angled plates separated by a space and proximate an outlet of the particulate matter sensor are positioned, wherein the plurality of flow plates is separated by a distance from the flow diverter. A sixth example of the method optionally includes one or more of the first to fifth examples, and further comprises passing the exhaust gas through the clearance formed at the inlet between the flow controller and the flow diverter into the space formed between the plurality of flow plates , in the direction of the fine dust sensor element, which is positioned in the vicinity of the outlet of the particulate matter sensor. A seventh example of the method optionally includes one or more of the first to sixth examples, and further includes detecting leaks in a particulate filter disposed upstream of the particulate matter sensor and indicating deterioration of the particulate filter based on a deposition rate of the particulate matter on the particulate matter sensor element. An eighth example of the method optionally includes one or more of the first to seventh examples and further includes the threshold rate being based on a desired deposition rate of the particulate matter on the particulate matter sensor element.

The systems and methods described above also provide a method for capturing particulate matter in a particulate matter sensor system, the method comprising: increasing exhaust flow into an FS sensor element disposed within the FS sensor, wherein the FS sensor is in one Exhaust flow channel is positioned in response to an exhaust gas flow rate in the exhaust gas flow channel is below a threshold, and reducing the exhaust gas flow into the FS sensor element in response to the exhaust gas flow rate is above the threshold. In a first example of the method, the method may additionally or alternatively include increasing the exhaust flow including rotating a flow rate controller disposed proximate an inlet port of the FS sensor in a first direction, and decreasing the exhaust flow rotating the exhaust flow Flow rate control in a second direction opposite the first direction includes flowing the exhaust gas between a plurality of flow diverters toward the FS sensor element positioned proximate the plurality of flow diverters. A second example of the method optionally includes the first example and further includes rotating the flow control in the first direction further including moving the flow rate control away from a flow plate located at or near the inlet port of the FS sensor, and wherein rotating the flow control in the second direction further includes moving the flow rate control toward the first flow plate of the FS sensor assembly. A third example of the method optionally includes one or more of the first and second examples, and further includes the plurality of flow diverters being separated by a space, and wherein each of the plurality of flow diverters includes a plate having an opening that communicates with a first Part of the exhaust gas is allowed to flow from the opening into the space between the plurality of flow diverters in the direction of Flow sensor element, and a second portion of the exhaust gas to flow toward the opening of an adjacent flow conductor, wherein the openings of adjacent flow diverter may have different sizes. A fourth example of the method optionally includes one or more of the first to third examples, and further includes a plurality of flow diverters being parallel to one another, and the space between adjacent flow diverters being uniform. A fifth example of the method optionally includes one or more of the first to fourth examples and further includes that the plurality of flow diverters are angled plates and that the space between adjacent flow diverters is non-uniform. A sixth example of the method optionally includes one or more of the first to fifth examples and further includes capturing a first set of particulates in the exhaust stream at the inlet port of the FS sensor, trapping a second set of particulates in the plurality of flow diversifiers, the second one A set of particles smaller than the first set of particles, and directing a third set of particles in the exhaust stream from the space between adjacent flow diverters toward an FS sensor element positioned at or near the plurality of flow diverters to prevent deposition of the particles third set of particles from the FS sensor element, wherein the third set of particles is smaller than each of the first set of particles and the second set of particles, and displaying a leak in a particulate filter, which is arranged upstream of the FS sensor if a deposition rate of the third set of Parti on the FS sensor element exceeds a threshold rate.

In another illustration, the method optionally includes one or more of the first to sixth examples, and further includes the flow plate directing the exhaust flow toward the flow diverter methods, and the plurality of flow plates further directing the exhaust flow toward the outlet of the FS sensor redirects.

The systems and methods described above also provide a particulate matter sensor, comprising: a first flow diverter proximate an inlet of the FS sensor, a plurality of second flow diverters, wherein the plurality of second flow diverters are separated by a distance from the first flow diverter an FS sensor element, wherein at least a portion of the FS sensor element is positioned between an uppermost flow diverter and a lowermost flow diverter of the plurality of second flow diverters, and a movable plate positioned at or near the inlet of the FS sensor, and which is designed to adjust an inlet opening of the inlet. In a first example of the particulate matter sensor, the sensor may additionally or alternatively include a controller having computer readable instructions stored in a nonvolatile memory for setting the movable platen to an end position at or between a first position with a smaller degree of opening the inlet and a second position with a greater extent of the opening of the inlet on the basis of an FS sensor upstream exhaust gas flow rate of the exhaust stream include. A second example of the particulate matter sensor optionally includes the first example, and further that adjusting the movable plate to the end position includes adjusting the movable plate closer to the first position than to the second position as the exhaust gas flow rate increases, and further adjusting the flow control closer the second position as to the first position includes when the exhaust gas flow rate decreases. A third example of the particulate matter sensor optionally includes one or more of the first and second examples, and further includes instructions for indicating a leak in a particulate filter upstream of the FS sensor when a current particulate matter deposition rate on the FS sensor is a desired particulate settling rate on the FS sensor exceeds.

It should be appreciated that the example control and estimation routines included herein may be used with various engine and / or vehicle system configurations. The control methods and routines disclosed herein may be stored as executable instructions in nonvolatile memory and executed by the control system including control in combination with the various sensors, actuators, and other engine hardware. The specific routines described herein may represent one or more of any number of processing strategies, such as event-driven, interrupt-driven, multi-tasking, multi-threading, and the like. Thus, various illustrated acts, acts, and / or functions may be performed in the illustrated order or in parallel, or omitted in some instances. Likewise, the processing order is not necessarily required to achieve the features and advantages of the example embodiments described herein, but rather provided for ease of illustration and description. One or more of the illustrated acts, acts, and / or functions may be repeatedly performed depending on the specific strategy employed. Further, the described acts, acts and / or functions may graphically represent code stored in a nonvolatile memory of the computer readable storage medium to be programmed in the engine control system by performing the described actions by executing the instructions in a system, including the various engine hardware components in combination with the electronic controller.

It should be understood that the configurations and routines disclosed herein are exemplary in nature and that these specific embodiments are not to be construed in a limiting sense as numerous variations are possible. For example, the above technology can be applied to V6, I-4, I-6, V-12, 4-cylinder Boxer and other types of internal combustion engines. The subject matter of the present disclosure includes all novel and non-obvious combinations and subcombinations of the various systems and configurations, and other features, functions, and / or properties disclosed herein.

In particular, the following claims set forth certain combinations and sub-combinations that are believed to be novel and not obvious. These claims may refer to "a" element or "first" element or the equivalent thereof. Such claims are to be understood to include the inclusion of one or more such elements and neither require nor preclude two or more such elements. Other combinations and sub-combinations of the disclosed features, functions, elements and / or properties may be claimed through amendment of the present claims or through the filing of new claims in this or a related application. Such claims, regardless of whether they have a broader, narrower, equal, or different scope of protection from the original claims, are also contemplated as being within the scope of the present disclosure.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 8225648 B2 [0004]

Claims (13)

Method, comprising: Adjusting an amount of opening of an inlet to a particulate matter sensor positioned in an exhaust stream in response to an exhaust gas flow rate of the exhaust stream upstream of the particulate matter sensor; and Flowing exhaust gas past a plurality of flow plates toward a particulate matter sensor element positioned proximate to the plurality of flow plates. The method of claim 1, wherein the adjusting includes increasing the amount of opening of the inlet when the exhaust gas flow rate falls below a threshold rate and further including decreasing the extent of opening of the inlet when the exhaust gas flow rate exceeds the threshold rate. The method of claim 2, wherein the particulate matter sensor includes a flow diverter and a flow controller positioned at the inlet, wherein the flow controller and the flow diverter are coupled to different opposing surfaces of the FS sensor such that a gap exists between the flow control and the flow diverter is formed at the inlet. The method of claim 3, wherein increasing the extent of opening comprises increasing the gap between the flow diverter and the flow control by rotating the flow control in a first direction away from the flow diverter. The method of claim 4, wherein decreasing the extent of opening comprises reducing the gap between the flow diverter and the flow control by rotating the flow control in a second direction opposite the first direction toward the flow diverter. The method of claim 3, wherein the plurality of flow plates comprises one or more of parallel plates and angled plates separated by a space and positioned proximate to an outlet of the particulate matter sensor, the plurality of flow plates being spaced from the flow diverter is disconnected. The method of claim 6, further comprising passing the exhaust gas through the gap formed at the inlet between the flow controller and the flow diverter into the space formed between the plurality of flow plates toward the particulate matter sensor element proximate to the first Outlet of the particulate matter sensor is positioned. The method of claim 7, further comprising detecting leaks in a particulate filter disposed upstream of the particulate matter sensor and indicating degradation of the particulate filter based on a deposition rate of the particulates on the particulate matter sensor element. The method of claim 8, wherein the threshold rate is based on a desired deposition rate of the particles on the particulate matter sensor element. Particulate matter (FS) sensor comprising: a first flow diverter near an inlet of the FS sensor; a plurality of second flow diverters, wherein the plurality of second flow diverters are separated by a distance from the first flow diverter; an FS sensor element, wherein at least a portion of the FS sensor element is positioned between an uppermost flow diverter and a lowermost flow diverter of the plurality of second flow diverters; and a movable plate positioned at or near the inlet of the FS sensor and configured to adjust an inlet port of the inlet. The sensor of claim 10, further comprising a controller having computer readable instructions stored on a nonvolatile memory for: Adjusting the movable platen to an end position at or between a first position having a smaller amount of opening the inlet and a second position having a greater extent of opening the inlet based on an exhaust gas flow rate of the exhaust gas flow upstream of the FS sensor. The sensor of claim 11, wherein adjusting the movable plate to the end position includes setting the movable plate closer to the first position than to the second position as the exhaust flow rate increases, and further adjusting the flow control closer to the second position than to the first position includes as the exhaust gas flow rate decreases. The system of claim 12, wherein the controller further includes instructions for indicating a leak in a particulate filter disposed upstream of the FS sensor when an actual rate of deposition of the particulate matter on the FS Sensor exceeds a desired settling rate of the particles on the FS sensor.

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