KR20230015206A - Apparatus and method for controlling diesel particulate filter - Google Patents

Abstract

The present invention relates to a diesel particulate filter control apparatus and a method thereof. The diesel particulate filter control apparatus of the present invention comprises: a diesel particulate filter (DPF) which collects soot in an exhaust gas discharged from a diesel engine; and a processor connected to the DPF. The processor determines whether a vehicle is loaded when a soot amount of the DPF reaches a first reference soot amount. When the vehicle is in a loaded status, DPF regeneration is performed. In addition, when the soot amount of the DPF falls below a second reference soot amount during regeneration of the DPF, the DPF regeneration is terminated. Provided are the diesel particulate filter control apparatus for controlling a regeneration entry point, and the method thereof.

Description

Diesel particulate filter control device and method {APPARATUS AND METHOD FOR CONTROLLING DIESEL PARTICULATE FILTER}

The present invention relates to a diesel particulate filter control apparatus and method.

A diesel particulate filter (DPF) is applied to a vehicle equipped with a diesel engine to cope with emission (EM) regulations. A DPF is a filtering device that removes diesel particulates from exhaust gas of a diesel engine, and is also called an exhaust gas aftertreatment device or an exhaust gas reduction device.

Existing DPF systems enter a DPF regeneration mode when a certain amount of shoot mass is collected regardless of vehicle driving patterns, and burn and remove the soot collected in the DPF. DPF regeneration proceeds for a long time when the vehicle is in an empty state, as the exhaust gas temperature is low. Accordingly, when regenerating the DPF, fuel consumption is inevitably deteriorated because additional fuel is required to increase the exhaust gas temperature.

For example, conventionally, DPF regeneration starts when the amount of soot collected in the DPF reaches about 83%, but assuming a truck driving at a constant speed of 60 km, only about 30% of the maximum load in an empty state (10t or less) and use more than 80% of the maximum load in the maximum load condition (over 25t). At this time, the exhaust gas temperature is 400°C when the load is 30% and 500°C when the load is 80%. Since a temperature of 550°C or higher is required to regenerate the DPF, when the load is low, there is no choice but to inject more HC (hydrocarbon) after injection than when the load is high. This reduces regeneration efficiency and deteriorates fuel efficiency due to excessive use of post-injection fuel, HC slip (a phenomenon in which fuel escapes to the outside), and a phenomenon in which a target temperature is not reached.

The present invention relates to a diesel particulate filter control apparatus and method for estimating vehicle weight using engine rotation speed, fuel amount, acceleration, and convergence speed of the vehicle, and controlling the DPF (Diesel Particulate Filter) regeneration entry point based on the predicted vehicle weight. want to provide

An apparatus for controlling a diesel particulate filter according to embodiments of the present invention includes a diesel particulate filter (hereinafter referred to as a DPF) that collects soot in exhaust gas discharged from a diesel engine, and a processor connected to the DPF, wherein the processor comprises: When the soot amount of the DPF reaches the first reference soot amount, it is determined whether the vehicle is in a loaded state, and if the vehicle is in the loaded state, the DPF is regenerated, and the DPF soot amount during the DPF regeneration is less than or equal to the second standard soot amount. When it falls to , it is characterized in that reproduction of the DPF is terminated.

The processor checks the number of transmission stages of the vehicle, logs the vehicle speed for each unit time when the engine is operated with the number of engine revolutions and the amount of fuel predetermined in the number of transmission stages, and the acceleration and convergence speed obtained based on the logged vehicle speed It is characterized in that it is determined whether the vehicle is in a loaded vehicle state based on.

The processor determines whether the acceleration and the convergence speed are less than the reference acceleration and the reference convergence speed, respectively, and determines that the vehicle is in a loading state when the acceleration and the convergence speed are less than the reference acceleration and the reference convergence speed, respectively. do.

Wherein the processor determines that the state of tolerance is determined when the acceleration is equal to or greater than the reference acceleration, when the convergence speed is greater than or equal to the reference convergence speed, or when the acceleration is greater than or equal to the reference acceleration and the convergence speed is greater than or equal to the reference convergence speed. to be

The processor determines whether the soot quantity of the DPF reaches a third reference suit quantity when the vehicle is not in a loaded state, and regenerates the DPF when the soot quantity of the DPF reaches the third reference suit quantity. to be characterized

The first standard suit amount is set to be larger than the second standard suit amount and smaller than the third standard suit amount.

The DPF control method according to the embodiments of the present invention includes determining whether the vehicle is loaded when the suit amount of the DPF reaches the first reference suit amount, regenerating the DPF when the vehicle is loaded, and the DPF and terminating reproduction of the DPF when the amount of soot of the DPF falls below a second reference soot amount during regeneration of the DPF.

The step of determining whether or not the vehicle is loaded may include checking the number of gears of the transmission of the vehicle, logging the vehicle speed for each unit time when the engine is operated with a predetermined number of engine revolutions and fuel amount in the gears of the transmission, and the logging and determining whether the vehicle is in a loaded vehicle state based on the obtained acceleration and convergence speed based on the obtained vehicle speed.

The step of determining whether the vehicle is in an overloaded vehicle state may include determining whether the acceleration and the convergence speed are less than the reference acceleration and the reference speed of convergence, respectively, and the acceleration and the speed of convergence are the reference acceleration and the reference speed of convergence, respectively. It is characterized in that it includes the step of determining that it is less than the loading vehicle state.

The step of determining whether the vehicle is in an overloaded vehicle state may include: when the acceleration is equal to or greater than the reference acceleration, when the convergence speed is greater than or equal to the reference convergence speed, or when the acceleration is greater than or equal to the reference acceleration and the convergence speed is greater than or equal to the reference convergence speed In this case, it is characterized in that it further comprises the step of determining the tolerance state.

If the vehicle is not loaded, checking whether the soot amount of the DPF has reached a third reference suit amount, and regenerating the DPF if the soot amount of the DPF reaches the third reference suit amount It is characterized by including.

According to the present invention, since the vehicle weight is predicted using the vehicle's engine speed, fuel amount, acceleration, and convergence speed, and the DPF regeneration entry point is controlled based on the predicted vehicle weight, DPF regeneration is efficiently controlled to reduce fuel consumption. can improve

Further, according to the present invention, since the DPF regeneration is performed only when driving with a high load by predicting the loading state of the vehicle, the DPF regeneration time can be reduced.

1 is a block configuration diagram showing a DPF control device according to embodiments of the present invention.
2 is a flowchart illustrating a DPF control method according to embodiments of the present invention.
FIG. 3 is a flowchart illustrating a method for determining a loaded vehicle state shown in FIG. 2 .

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. In adding reference numerals to components of each drawing, it should be noted that the same components have the same numerals as much as possible even if they are displayed on different drawings. In addition, in describing an embodiment of the present invention, if it is determined that a detailed description of a related known configuration or function hinders understanding of the embodiment of the present invention, the detailed description will be omitted.

In describing the components of the embodiment of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only used to distinguish the component from other components, and the nature, order, or order of the corresponding component is not limited by the term. In addition, unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which the present invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and unless explicitly defined in the present application, it should not be interpreted in an ideal or excessively formal meaning. don't

The present invention relates to a technology for improving fuel efficiency of a vehicle by controlling the regeneration timing of a diesel particulate filter (DPF) mounted on a vehicle equipped with a diesel engine. DPF regeneration refers to a process of continuously removing soot collected in DPF.

1 is a block configuration diagram showing a DPF control device according to embodiments of the present invention.

Referring to FIG. 1 , the DPF control device 100 may include an engine controller 110, a transmission controller 120, a vehicle speed sensor 130, a memory 140, a DPF 150, and a processor 160. .

The engine controller 110 may control the operation of a diesel engine (hereinafter, engine) mounted in the vehicle. The engine controller 110 may control the driving torque of the engine according to accelerator pedal position information output from the accelerator pedal position sensor. The engine controller 110 may control the fuel injection amount (fuel amount) according to an accelerator pedal position (a degree of depressing the accelerator pedal), engine revolutions per minute (rpm), coolant temperature, and/or air intake. The engine controller 110 may transmit the number of revolutions of the engine and the amount of fuel to the processor 160 .

The shift controller 120 may control the transmission of the vehicle. The shift controller 120 may provide the transmission range to the processor 160 .

The engine controller 110 and the transmission controller 120 described above may be implemented as an electronic control unit.

The vehicle speed sensor 130 may measure (detect) the vehicle speed. The vehicle speed sensor 130 may include a reed switch type vehicle speed sensor, a photoelectric vehicle speed sensor, and/or an electronic vehicle speed sensor.

The memory 140 may store a mapping table, a logic for determining a loading state, a first reference soot mass, a second upper limit soot mass, and a lower limit soot mass. Here, acceleration and convergence speed (vehicle speed) according to the number of transmission stages, engine speed, and amount of fuel may be defined in the mapping table through a test in advance. Acceleration means the acceleration of the vehicle, and may mean a change in vehicle speed at predetermined engine rpm, fuel amount, and gear ratio. The convergence speed may refer to a vehicle speed that converges when driving with maximum load. For example, it may be determined that convergence occurs when the speed increases to 3 km/h or less for 2 seconds at maximum load.

The memory 140 may be a non-transitory storage medium that stores instructions executed by the processor 160 . The memory 140 includes a flash memory, a hard disk, a solid state disk (SSD), a random access memory (RAM), a static random access memory (SRAM), a read only memory (ROM), and a PROM ( It may include at least one of storage media such as Programmable Read Only Memory (EEPROM), Electrically Erasable and Programmable ROM (EEPROM), Erasable and Programmable ROM (EPROM), and/or a register.

The DPF 150 may collect soot in the exhaust gas discharged from the engine and burn the collected soot to remove it. The DPF 150 may be regenerated through a soot combustion process. The DPF 150 may also include a sensor for measuring the collected amount of soot.

The processor 160 may control overall operations of the DPF control device 100 . The processor 160 may include application specific integrated circuits (ASICs), digital signal processors (DSPs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), central processing units (CPUs), microcontrollers, and/or It may include at least one of processing devices such as microprocessors.

The processor 160 predicts the loading state (weight) of the vehicle using the number of transmission stages, engine revolutions, fuel amount, acceleration, convergence speed, etc., and adjusts (controls) the playback time of the DPF 150 based on the prediction result. can

The processor 160 may detect the amount of soot collected in the DPF 150 . The processor 160 calculates the amount of soot collected in the DPF 150 by using a method for calculating the amount of collected soot using a sensor, a known method for calculating the amount of collected soot, and/or a method using a statistical technique. can be detected. When the collected amount of soot reaches the first standard amount of soot, the processor 160 may enter a mode for determining the loading state. The first reference suit amount may be a criterion for determining whether to enter the loading state determination mode. For example, the processor 160 may execute a loading vehicle state determination logic when the collected soot amount reaches 65%.

The first standard amount of soot may be set lower than the existing amount of soot for the following reasons. First, the smaller the amount of soot collected, the lower the efficiency of DPF regeneration, so the amount of soot reduction is lower at the same exhaust gas temperature. When the engine load is low and the exhaust gas temperature is low in a situation where the amount of soot collected is low, the regeneration efficiency is further lowered. When driving with a high load, the exhaust gas temperature is basically maintained high, so that high regeneration efficiency can be maintained even in low soot collection conditions. In addition, when regeneration is started at a low soot amount, a situation in which the internal temperature of the DPF rises significantly does not occur, which is advantageous in terms of durability. Second, during practical driving of a vehicle such as a truck, the empty vehicle state is converted to the loaded vehicle state every 3-4 hours. Since about 15-20% of the suit is collected during 3-4 hours of driving, starting the logic to determine the loading status at 84% increases the probability of starting DPF regeneration when the suit amount is empty at 90%. Therefore, the soot standard amount was lowered so that DPF regeneration starts when the suit amount is within 90% of the loaded vehicle state by starting the logic for determining the loaded vehicle state at 65% of the suit amount.

The processor 160 may check the number of transmission stages according to the loaded vehicle state determination logic. The processor 160 may receive the transmission range from the shift controller 120 .

The processor 160 may log the vehicle speed obtained by the vehicle speed sensor 130 for every unit of time when the engine is operated at a predetermined engine rpm and fuel amount in the confirmed transmission range. Processor 160 may log vehicle speed for a predetermined period of time. For example, the processor 160 may record the vehicle speed in units of 1 second for 5 seconds while driving at a predetermined engine rpm and fuel amount.

The processor 160 may determine the acceleration and convergence speed during driving with the predetermined engine rpm and fuel amount in the transmission gear identified in the mapping table stored in the memory 140 and set them as the reference acceleration and reference convergence speed.

The processor 160 may check whether the vehicle's acceleration and convergence speed are less than the reference acceleration and reference convergence speed, respectively. The processor 160 may determine the vehicle state as a loaded vehicle state when the acceleration of the vehicle is less than the reference acceleration and the convergence speed of the vehicle is less than the reference convergence speed. Processor 160 sets the vehicle state to the tolerance state when the acceleration of the vehicle is greater than or equal to the reference acceleration, the convergence speed of the vehicle is greater than or equal to the reference convergence speed, or the acceleration of the vehicle is greater than or equal to the reference acceleration and the convergence speed of the vehicle is greater than or equal to the reference convergence speed. can be judged by In this embodiment, acceleration and convergence speed are used as criteria for determining the loading state of the vehicle, for the following reasons. In large trucks, vehicle acceleration can vary greatly depending on the empty vehicle condition and the loaded vehicle condition even when the same engine is running. In particular, when driving with 100% load when starting from a standstill from a fully loaded vehicle, the acceleration does not rise by more than 10 km/h per second, so the driver only drives with the maximum load, which is advantageous for logic setting. In addition, in the empty state, the speed converges at a maximum load of 100 km/h or higher, but in a loaded vehicle state, the maximum load may not exceed 80 km/h.

The processor 160 may determine to enter the DPF regeneration mode when it is determined that the vehicle state is a loaded vehicle state. The processor 160 may determine not to enter the DPF regeneration mode when it is determined that the vehicle state is an empty vehicle state.

When it is determined to enter the DPF play mode, the processor 160 may instruct the DPF 150 to perform a play process. The DPF 150 may burn and remove the collected soot according to instructions of the processor 160 .

While regeneration of the DPF 150 is being performed, the processor 160 may check whether or not the amount of soot in the DPF 150 reaches the second reference amount of soot or less. The second reference suit amount may be a criterion for determining whether to end DPF reproduction. The processor 160 may terminate reproduction of the DPF 150 when the amount of soot in the DPF 150 reaches the second reference amount of soot (eg, 15%) or less.

When it is determined that the DPF reproduction mode is not entered, the processor 160 may check whether the soot amount in the DPF 150 reaches the third reference soot amount (eg, 90%). When the amount of suits in the DPF 150 reaches the third reference suit amount, the processor 160 may determine to enter the DPF regeneration mode regardless of the vehicle's loading state. Thereafter, the processor 160 may check whether or not the amount of soot in the DPF 150 is equal to or less than the second reference amount of soot during reproduction of the DPF 150 . The processor 160 may instruct the DPF 150 to terminate reproduction of the DPF when the amount of soot in the DPF 150 falls below the lower limit soot amount.

According to the above embodiment, the loaded vehicle state is predicted based on the vehicle's engine rpm, fuel amount, acceleration, convergence speed, etc., and DPF regeneration is performed in the loaded vehicle state, and DPF regeneration is suspended in the empty state. Driving situation), the DPF regeneration time is increased by increasing the probability of DPF regeneration, and fuel efficiency can be improved by efficiently performing DPF regeneration.

2 is a flowchart illustrating a DPF control method according to embodiments of the present invention.

The processor 160 may check whether the amount of soot in the DPF 150 reaches the first reference amount of soot (S100). The first standard suit quantity is a criterion for determining whether to enter the loaded vehicle state determination mode (whether or not to perform the loaded vehicle state determination), and may be set in advance by a designer. In addition, the first standard soot amount (eg, 65%) may be set lower than the existing DPF reproduction start standard soot amount (eg, 83%).

When the amount of soot in the DPF 150 reaches the first standard amount of soot, the processor 160 may determine a vehicle state (S110). When the amount of soot collected in the DPF 150 reaches the first standard amount of soot, the processor 160 determines to enter the loading vehicle state determination mode, and when the amount of soot collected in the DPF 150 does not reach the first standard amount of soot It may wait until the amount of soot collected in the DPF 150 reaches the first reference amount of soot.

The processor 160 may determine whether the vehicle is in the loaded vehicle state based on the result of determining the loaded vehicle state (S120).

When the vehicle is in a loaded state, the processor 160 may enter a DPF regeneration mode (S130). The processor 160 may instruct the DPF 150 to start playback. The DPF 150 may burn and remove the soot collected in the DPF 150 under the control of the processor 160 .

While the DPF is being reproduced, the processor 160 may check whether or not the amount of soot in the DPF 150 is equal to or less than the second reference amount of soot (S140). The second standard suit amount may be previously set by a designer like the first standard suit amount.

When the amount of soot in the DPF 150 is less than or equal to the second reference amount of soot, the processor 160 may end playback of the DPF 150 (S150). The processor 160 may regenerate the DPF 150 until the amount of soot in the DPF 150 reaches the second reference amount of soot (eg, 15%) or less.

If the vehicle is not in a loaded state at S120, the processor 160 may check whether the soot amount in the DPF 150 has reached the third standard soot amount (S160). When the vehicle state is an empty state, the processor 160 may determine whether the amount of soot collected in the DPF 150 has reached the third reference soot amount (eg, 90%).

When the amount of soot in the DPF 150 reaches the third reference amount of soot, the processor 160 may perform operations after S130. When the suit amount in the DPF 150 reaches the third reference suit amount, the processor 160 may enter the DPF regeneration mode regardless of the vehicle's loading state (S130). When the amount of soot in the DPF 150 falls below the second reference amount of soot due to DPF regeneration, the processor 160 may end DPF regeneration (S140 and S150).

FIG. 3 is a flowchart illustrating a method for determining a loaded vehicle state shown in FIG. 2 .

When the loaded vehicle state determination logic is executed in S110, the processor 160 may check the number of transmission stages (S111). The processor 160 may check the number of transmission stages through the shift controller 120 . In the present embodiment, checking the number of transmission stages using the shift controller 120 has been described as an example, but is not limited thereto and the number of transmission stages may be checked using a sensor.

The processor 160 may log the vehicle speed for every predetermined unit time (eg, 1 second) when driving with a predetermined engine rpm and fuel amount in the confirmed transmission stage (S112). The processor 160 may record the vehicle speed for a predetermined period of time (eg, 5 seconds).

The processor 160 may check whether the vehicle's acceleration and convergence speed are less than the reference acceleration and reference convergence speed, respectively (S113). The processor 160 may determine the acceleration and convergence speed of the vehicle based on the logged vehicle speed. The processor 160 may refer to the mapping table stored in the memory 140 to determine reference values, ie, reference acceleration and reference convergence speed, when driving with a predetermined engine rpm and fuel amount in the identified transmission range.

When the acceleration and convergence speed of the vehicle are less than the reference acceleration and reference convergence speed, respectively, the processor 160 may determine the vehicle state as the loaded vehicle state (S114).

The processor 160 may determine the vehicle state as an empty vehicle state when the vehicle's acceleration and convergence velocity are not less than the reference acceleration and reference convergence velocity, respectively, in S113 (S115). The processor 160 may determine the vehicle state as an empty vehicle state when the acceleration is equal to or greater than the reference acceleration, when the convergence speed is greater than or equal to the reference convergence speed, or when the acceleration is greater than or equal to the reference acceleration and the convergence speed is greater than or equal to the reference convergence speed.

The above description is merely an example of the technical idea of the present invention, and various modifications and variations can be made to those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be construed according to the claims below, and all technical ideas within the equivalent range should be construed as being included in the scope of the present invention.

Claims (12)

a diesel particulate filter (hereinafter referred to as DPF) that collects soot in exhaust gas discharged from a diesel engine; and
A processor connected to the DPF,
the processor,
When the amount of soot in the DPF reaches a first reference amount of soot, it is determined whether or not the vehicle is loaded;
When the vehicle is in a loaded state, regeneration of the DPF is performed;
Wherein the DPF regeneration is terminated when the amount of soot of the DPF falls below a second reference soot amount during regeneration of the DPF.
The method of claim 1,
the processor,
Check the number of transmission stages of the vehicle,
Logging the vehicle speed per unit time when the engine is operated with the number of engine revolutions and fuel amount determined in the number of transmission stages,
The diesel particulate filter control device, characterized in that for determining whether the vehicle is in a loaded state based on the acceleration and convergence speed obtained based on the logged vehicle speed.
The method of claim 2,
the processor,
Check whether the acceleration and the convergence rate are less than the reference acceleration and the reference convergence speed, respectively;
The diesel particulate filter control device according to claim 1 , wherein the vehicle condition is determined when the acceleration and the convergence speed are less than the reference acceleration and the reference speed of convergence, respectively.
The method of claim 3,
the processor,
Diesel particulates characterized in that when the acceleration is equal to or greater than the reference acceleration, when the convergence speed is greater than or equal to the reference convergence speed, or when the acceleration is greater than or equal to the reference acceleration and the convergence speed is greater than or equal to the reference convergence speed, the state of tolerance is determined. filter control unit.
The method of claim 1,
the processor,
If the vehicle is not in a loaded state, check whether the soot amount of the DPF has reached a third standard soot amount;
and regenerating the DPF when the soot amount of the DPF reaches a third reference soot amount.
The method of claim 5,
The first reference suit amount,
The diesel particulate filter control device, characterized in that set greater than the second standard soot amount and smaller than the third standard soot amount.
determining whether the vehicle is loaded when the amount of soot of the diesel particulate filter (hereinafter referred to as DPF) reaches a first reference amount of soot;
regenerating a DPF when the vehicle is in a loaded state; and
and terminating the DPF regeneration when the amount of soot of the DPF falls below a second reference soot amount during regeneration of the DPF.
The method of claim 7,
The step of determining whether the vehicle is loaded or not,
Checking the number of gears of the transmission of the vehicle;
logging a vehicle speed per unit time when the engine is operated with a predetermined number of engine revolutions and fuel amount in the transmission range; and
and determining whether the vehicle is in a loaded state based on the acceleration and convergence speed obtained based on the logged vehicle speed.
According to claim 8,
Determining whether the vehicle is in a loaded vehicle state,
checking whether the acceleration and the convergence rate are less than a reference acceleration and a reference convergence rate, respectively; and
and determining a full vehicle state when the acceleration and the convergence speed are less than the reference acceleration and the reference speed of convergence, respectively.
The method of claim 9,
Determining whether the vehicle is in a loaded vehicle state,
Further comprising determining an empty state when the acceleration is equal to or greater than the reference acceleration, when the convergence speed is greater than or equal to the reference convergence speed, or when the acceleration is greater than or equal to the reference acceleration and the convergence speed is greater than or equal to the reference convergence speed. Diesel particulate filter control method characterized.
The method of claim 7,
If the vehicle is not in a loaded state, confirming whether the soot amount of the DPF has reached a third standard soot amount; and
and regenerating the DPF when the soot amount of the DPF reaches a third reference soot amount.
The method of claim 11,
The first reference suit amount,
A method for controlling a diesel particulate filter, characterized in that the second standard soot amount is set to be larger than the third standard soot amount to be smaller than the third standard soot amount.

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