Claims:We claim:
1. An exhaust gas re-circulation (EGR) valve control system (110) for enabling real time cleaning of a plurality of EGR valve (109) to avoid deposition of soot particles inside the plurality of EGR valve (109), the EGR valve control system (110) comprising:
an Engine Control Unit (ECU) (100) having a processor (103) communicatively coupled with hardware interface (102), a memory (101), and an EGR valve controller (104), the EGR valve controller (104) coupled with:
a fuel injection sensor (105) for determining engine cut off condition;
an engine speed sensor (107) for determining whether speed of engine is in between threshold value 1 and threshold value 2;
a vehicle speed sensor (106) for determining whether speed of vehicle is above threshold value;
a brake switch (108) for determining whether brake pedal is pressed;
wherein, the EGR valve controller (104) configured within the ECU (100) to operate the plurality of EGR valve (109) in fully opened and fully closed condition for cleaning when the engine is in cutoff mode, the engine speed is in between the threshold value 1 and the threshold value 2, the vehicle speed is above the minimum threshold value, vehicle is in transmission gear, and that the brake pedal is pressed.
2. The EGR valve control system (110) as claimed in claim 1, wherein the EGR valve controller (104) operates the plurality of EGR valve (109) in fully opened and fully closed condition for a predetermined number of times.

3. The EGR valve control system (110) as claimed in claim 1, wherein the EGR valve controller (104) re-initialize the fully opened and fully closed condition of the plurality of EGR valve (109) after a threshold time period from the previous cleaning.

4. The EGR valve control system (110) as claimed in claim 1, wherein the fully opened and fully closed condition of the plurality of EGR valve (109) allows passage of exhaust gases flow through the plurality of EGR valve (109) to remove the soot particles.

5. A method (200) for enabling real time cleaning of a plurality of exhaust gas re-circulation (EGR) valve (109) to avoid deposition of soot particles inside the plurality of exhaust gas re-circulation (EGR) valve (109), the method (200) comprising:
determining (201, 202) whether engine is in cut off mode;
determining (203), by engine speed sensor (107), whether engine speed is in between threshold value 1 and threshold value 2;
determining (203), by vehicle speed sensor (106), whether vehicle speed is above a minimum threshold value;
determining (205) whether vehicle is transmission is in gear;
determining (206), by brake switch (108), whether brake signal is true; and
enabling (207) real time cleaning of the plurality of exhaust gas re-circulation (EGR) valve (109) when the engine is in cutoff mode, the engine speed is in between the threshold value 1 and the threshold value 2, the vehicle speed is above the minimum threshold value, the vehicle is in transmission gear, and that the brake signal is true.
6. The method (200) as claimed in claim 7, wherein the method (200) further comprises:
determining (208) whether number of cleaning cycle of the plurality of exhaust gas re-circulation (EGR) valve (109) is equal to a predetermined number; and
starting (209) timer for next cleaning cycle when number of cleaning cycle of the plurality of exhaust gas re-circulation (EGR) valve (109) is equal to a predetermined number.
7. The method (200) as claimed in claim 7, wherein the method (200) further comprises:
determining (210), by timer, whether time period gap from last cleaning cycle is above predetermined time period; and
re-initializing (211) the method (200) for enabling cleaning of the plurality of EGR valve (109) when the determined time period gap is above the predetermined time period.
8. The method (200) as claimed in claim 8, wherein the re-initializing (211) step comprises:
performing all steps of method (200) for cleaning.

9. The method (200) as claimed in claim 8, wherein the engine cut off mode means fuel supply to the engine is zero.
10. The method (200) as claimed in claim 7, wherein the number of cleaning cycles of the plurality of EGR valve (109) depends on engine task time of vehicle.
11. The method (200) as claimed in claim 7, wherein the step enabling (207) allows fully opened and fully closed operations of the plurality of EGR valve (109).
, Description:A SYSTEM AND A METHOD FOR REAL TIME EXHAUST GAS RECIRCULATION (EGR) VALVE CLEANING
FIELD OF INVENTION:
[001] The present subject matter described herein, relates to a system and a method for real time exhaust gas recirculation (EGR) valve cleaning of internal combustion engine in vehicle, and in particularly, to a method and a system in Engine Control Unit (ECU) of the vehicle to control opening and closing of EGR valve to perform cleaning action of the EGR valve. More particularly, the present subject matter relates to a system to improve functional durability of EGR valve by enabling EGR cleaning during vehicle driving operations.
BACKGROUND AND PRIOR ART:
[002] Generally, Exhaust gas recirculation is used to improve emission performance of internal combustion engines, such as petrol engine, CNG engine, and diesel engine. Working of the engine generates exhaust gases which contains unburned hydrocarbons and NOx. Formation of NOx will occur at higher combustion temperatures inside the combustion engine. In order to reduce formation of the NOx in the engine, the temperature of the engine cylinder has to be lowered which is done by mixing the exhaust gases with the fresh intake air which causes improper combustion in the engine. Further, the exhaust gas recirculation systems have been developed to effectively reduce combustion temperatures and control emissions. Exhaust gas recirculation systems re-circulates a portion of the exhaust gas from the engine back to the intake manifold where it can combined with incoming fresh air. When the mixture is compressed and ignited in the cylinder the result is a lower combustion temperature and the reduction of NOx. In order to make the recirculation of exhaust gas possible, exhaust gas recirculation systems use exhaust gas recirculation (EGR) valves to open and close the conduits that re-circulate the exhaust gas back to the intake manifold of the engine.
[003] The composition of exhaust gas has contaminants, such as soot particles which effect the operation of the EGR valve. These contaminants typically adhere to the EGR valve components, such as valve piston and shaft, and restrict movement of the components. Over the time, the soot particles get deposited inside the EGR valve and effects working of the EGR valve which results in lesser fresh air inside the combustion chamber and thus leading to poor and improper combustion torque generation and uncontrolled emissions.

[004] Therefore, deposition of soot particles on the EGR valve impedes the movement of the valve and allows more exhaust gases to mix with the fresh air. In view of the above, it is beneficial to have a real time EGR valve cleaning system and method which can clean the EGR valve periodically without affecting the performance and working of the engine. Accordingly, the present subject matter of the invention provides a system and a method for real time cleaning of the EGR valve to avoid deposition of the soot particles on the EGR valve.
OBJECTS OF THE INVENTION:
[005] The principal object of the present invention is to provide a system and a method for real time EGR valve cleaning to avoid deposition of soot particles inside the EGR valve.
[006] Another object of the present subject matter is to provide a system which performs EGR valve cleaning during vehicle driving operation.
[007] Another object of the present subject matter is to provide a method and a system in Engine Control Unit (ECU) which do not require any other component to perform real time EGR valve cleaning.
[008] Another object of the present subject matter is to provide a system and a method which operates the EGR valve in fully closed and fully opened condition during cleaning process.
[009] Yet another object of the present subject matter is to provide a system and a method which directs the exhaust gas flow through EGR valve when engine cut off condition is present.
[0010] Yet another object of the present invention is to provide a simple and inexpensive system for performing real time EGR valve cleaning to avoid deposition of soot particles.
SUMMARY OF THE INVENTION:
[0011] The subject matter disclosed herein relates to a system and a method for enabling real time Exhaust Gas Re-circulation (EGR) valve cleaning to avoid deposition of soot particles inside the EGR valve. The present system improves functional durability of EGR valve by enabling EGR cleaning during vehicle driving operation. The present system enables EGR valve cleaning to avoid soot deposition. The present system works during engine cut-off mode based on enabling engine operating conditions. During cleaning cycle, EGR valve operates frequently in-between fully closed and fully open condition. The fully opened and fully closed operations of the EGR valve happen multiple times to ensure cleaning of EGR valve. When EGR is in fully open condition, exhaust gases flow through the EGR valve with higher flow rate and higher turbulence. During opening and closing operation of the EGR valve, accumulated soot particles on the valve are gradually flushed out with exhaust gas. As soot particles do not get deposited on the EGR valve, chances of EGR valve stuck become less.
[0012] In order to further understand the characteristics and technical contents of the present subject matter, a description relating thereto will be made with reference to the accompanying drawings. However, the drawings are illustrative only but not used to limit scope of the present subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] It is to be noted, however, that the appended drawings illustrate only typical embodiments of the present subject matter and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally effective embodiments. The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system or methods in accordance with embodiments of the present subject matter are now described, by way of example, and with reference to the accompanying figures, in which:
[0014] Fig. 1 illustrates EGR valve control system of a vehicle with Engine Control Unit along with hardware embodiments, in accordance with an embodiment of the present subject matter;
[0015] Fig. 2 illustrates a method for real time EGR valve cleaning to avoid soot deposition, in accordance with an embodiment of the present subject matter; and
[0016] Fig. 3 illustrates schematic diagram of one EGR cleaning cycle, in accordance with an embodiment of the present subject matter.
[0017] The figures depict embodiments of the present subject matter for the purposes of illustration only. A person skilled in the art will easily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DESCRIPTION OF THE PREFERRED EMBODIMENTS:
[0018] The subject matter disclosed herein relates to a system and a method for enabling real time Exhaust Gas Re-circulation (EGR) valve cleaning to avoid deposition of soot particles inside the EGR valve. The present system improves functional durability of EGR valve by enabling EGR cleaning during vehicle driving operation. The present system enables EGR valve cleaning to avoid soot deposition. The present system works during engine cut-off mode based on enabling engine operating conditions. During cleaning cycle, EGR valve operates frequently in-between fully closed and fully open condition. The fully opened and fully closed operations of the EGR valve happen multiple times to ensure cleaning of EGR valve. When EGR is in fully open condition, exhaust gases flow through the EGR valve with higher flow rate and higher turbulence. During opening and closing operation of the EGR valve, accumulated soot particles on the valve are gradually flushed out with exhaust gas. As soot particles do not get deposited on the EGR valve, chances of EGR valve stuck become less.
[0019] In an embodiment of the present subject matter, the present exhaust gas re-circulation (EGR) valve control system controls the opening and closing of EGR valve upon fulfilling certain predefined conditions. The exhaust gas re-circulation (EGR) valve control system is configured within Engine Control Unit (ECU) of the vehicle. The ECU has a processor which is communicatively coupled with hardware interface, a memory, and an EGR valve controller for controlling the operations of the EGR valve for cleaning process. The EGR valve controller coupled with the processor for receiving a plurality of inputs from a plurality of sensors. The EGR valve controller coupled with the plurality of sensors to sense/receive various engine operating condition to enable real time EGR valves cleaning process. The EGR valve controller coupled with fuel injection sensor for determining engine cut off condition is achieved. The EGR valve controller coupled with an engine speed sensor for determining whether speed of engine is in between threshold value 1 and threshold value 2 and with a vehicle speed sensor for determining whether speed of vehicle is above threshold value. The EGR valve controller operates the plurality of EGR valve in fully opened and fully closed condition for cleaning when the engine is in cutoff mode, the engine speed is in between the threshold value 1 and the threshold value 2, the vehicle speed is above the minimum threshold value, vehicle is in transmission gear, and that the brake pedal is pressed. By implementing the present system in the ECU, the ECU enables the cleaning process real time, i.e., during vehicle running condition to clean the EGR valves to avoid soot deposition inside the EGR valve.
[0020] It should be noted that the description and figures merely illustrate the principles of the present subject matter. It should be appreciated by those skilled in the art that conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present subject matter. It should also be appreciated by those skilled in the art that by devising various arrangements that, although not explicitly described or shown herein, embody the principles of the present subject matter and are included within its spirit and scope. Furthermore, all examples recited herein are principally intended expressly to be for pedagogical purposes to aid the reader in understanding the principles of the present subject matter and the concepts contributed by the inventor(s) to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. The novel features which are believed to be characteristic of the present subject matter, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures.
[0021] These and other advantages of the present subject matter would be described in greater detail with reference to the following figures. It should be noted that the description merely illustrates the principles of the present subject matter. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described herein, embody the principles of the present subject matter and are included within its scope.
[0022] The present subject matter describes a method and a system for enabling real time Exhaust Gas Re-circulation (EGR) valve cleaning to avoid deposition of soot particles inside the EGR valve. The present system and the method clean the EGR valve itself using high flow rate of exhaust gases to remove the accumulated soot particles. During EGR cleaning cycle, EGR valve operates from fully open condition to fully closed condition frequently for short duration. When EGR is in fully open condition, exhaust gases flow through the valve with higher flow rate and higher turbulence. During opening and closing operation of EGR valve, accumulated soot particles on the valve are gradually flushed out with exhaust gas. As soot particle do not get deposited on the valve, chances of EGR valve stuck become less.
[0023] Fig. 1 illustrates EGR valve control system of a vehicle within Engine Control Unit along with hardware embodiments for enabling the real time cleaning of the EGR valve, in accordance with an embodiment of the present subject matter. The EGR valve control system 110 has an Engine Control Unit (ECU) 100 which has a processor 103, hardware interface 102, and a memory 101 for storing logics and doing calculations to determine the objective of the present subject matter. The exhaust gas re-circulation (EGR) valve control system 110 is configured within Engine Control Unit (ECU) 100 of the vehicle. The ECU 100 has a processor 103 which is communicatively coupled with hardware interface 102, a memory 101, and an EGR valve controller 104 for controlling the operations of the EGR valve 109 for cleaning process. The EGR valve controller 104 coupled with the processor 103 for receiving a plurality of inputs from a plurality of sensors. The EGR valve controller 104 is coupled with the plurality of sensors to sense/receive various engine operating condition to enable real time EGR valves cleaning process. The EGR valve controller 104 is coupled with vehicle speed sensor 106, engine speed sensor 107, a plurality of EGR valve 109, and brake sensor 108, fuel injection sensor 105 via the hardware interface 102.
[0024] The processor(s) 103, may be implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, logic circuitries, and/or any devices that manipulate signals based on operational instructions. Among other capabilities, the processor(s) 103 is configured to fetch and execute computer-readable instructions stored in the memory 101. The functions of the various elements shown in the figure, including any functional blocks labeled as “processor(s)”, may be provided through the use of dedicated hardware as well as hardware capable of executing computer readable instructions or logics in association with appropriate software. When provided by a processor, the functions may be provided by a single dedicated processor, by a single shared processor, or by a plurality of individual processors, some of which may be shared. Moreover, explicit use of the term “processor” should not be construed to refer exclusively to hardware capable of executing software, and may implicitly include, without limitation, digital signal processor (DSP) hardware, network processor, application specific integrated circuit (ASIC), field programmable gate array (FPGA), read only memory (ROM) for storing software, random access memory (RAM), non-volatile storage. Other hardware, conventional and/or custom, may also be included.
[0025] The hardware interface 102 may include a variety of software and hardware interfaces, for example, interfaces for peripheral device(s), such as sensors, actuators, and an external memory. The hardware interface 102 is suitable for interfacing with the sensor and actuators as referred in the figure 1. The memory 103 can include any computer-readable medium known in the art including, for example, volatile memory, such as static random access memory (SRAM) and dynamic random access memory (DRAM), and/or non-volatile memory, such as read only memory (ROM), erasable programmable ROM, flash memories, hard disks, optical disks, and magnetic tapes. Generally construction of the ECU 100 is well known in the art. The processor 103 is operatively coupled with the memory 102 and the hardware interface 102 to execute the instructions for running the ECU 100. These instruction or logics may be encoded in the programs that are stored in the memory 101. Further, all the output of the system and calculation of the ECU also stores in the memory 101 for future determinations.
[0026] The EGR valve controller 104 coupled with the fuel injection sensor 105 to sense engine cut off condition. The engine cut off condition is achieved when there is no fuel supply into the engine. On the basis of the fuel injection sensor, the EGR valve controller 104 determines whether the engine is in fuel cut off condition.
[0027] The vehicle speed sensor 106 coupled with the EGR valve controller 104 of the ECU 100 via the hardware interface 102 to provide vehicle speed input. The EGR valve controller 104 receives the input from the vehicle speed sensor 106 and determines the speed of the vehicle. The EGR valve controller 104 determined speed of the vehicle by the vehicle speed sensor 106. The EGR valve controller 104 coupled with an engine speed sensor 107 via hardware interface 102 to receive inputs about engine speed for determination. The EGR valve controller 104 determines whether speed of the engine is in the predetermined range. The engine speed sensor 107 provides engine speed, i.e., is in RPM inputs to the ECU 100 for calculation. The EGR valve controller 104 is coupled with brake switch sensor 108 to determine whether brake pedal is pressed. The EGR valve controller 104 is coupled with a plurality of EGR valve 109. The EGR valve controller 104 controls opening and closing of the plurality of EGR valve 109 upon satisfying various conditions for cleaning the plurality of EGR valve 109.
[0028] Upon satisfying a plurality of conditions as disclosed in the figure 2, the EGR valve controller 104 operates the plurality of EGR valve 109 in fully opened and fully closed condition for cleaning when the engine is in cutoff mode, the engine speed is in between the threshold value 1 and the threshold value 2, the vehicle speed is above the minimum threshold value, vehicle is in transmission gear, and that the brake pedal is pressed.
[0029] Referring to fig. 2 which describes a method for enabling real time cleaning of a plurality of EGR valve to avoid deposition of soot particles on the EGR valve, in accordance with an embodiment of the present subject matter. The method 200 discloses how the present system works to enable cleaning of the EGR valve based on real time parameters of the plurality of sensor. As per the present method, the ECU (Engine Control Unit) 100 having the EGR valve controller 104 checks the certain defined conditions to perform EGR cleaning cycle. These conditions are engine cut-off mode, engine speed, vehicle speed, gear selection and brake signal. These conditions are pre-defined in an order to eliminate the negative impacts of cleaning cycle during driving operation.
[0030] Referring to step 201 and 202 of the figure 2, the EGR valve controller 104 determines whether the engine is in cut off mode during driving operation. The EGR valve controller 104 receives the inputs from the fuel injection sensor whether there is any fuel supply in the engine. If there is a fuel supply inside the engine, the engine is not in cut off mode. When there is no fuel supply, i.e. zero fuel supply detected by the EGR valve controller 104 based on the inputs from the fuel injection sensor 105, the EGR valve controller 104 determines that the engine is in cutoff mode. If the engine is in cutoff mode, the EGR valve controller 104 proceeds to step 203 for further determining. If not, the method is reinitiated.
[0031] Referring to step 203, the EGR valve controller 104 determines engine speed in RPM via the engine speed sensor 107. The EGR valve controller 104 determines whether the engine speed is in between pre-defined lower and upper threshold limits, i.e., threshold value 1 and the threshold value 2. When the engine speed is within the predefined threshold limits, the EGR valve controller 104 moves further to determine other conditions. If the engine speed is in between the predefined threshold limit, the EGR valve controller 104 proceeds to step 204 to determine vehicle speed. If not, the method is reinitiated.
[0032] Referring to step 104, the EGR valve controller 104 determines vehicle speed via the vehicle speed sensor 106. The EGR valve controller 104 determines whether the vehicle speed is above minimum threshold value. When the vehicle speed is greater than the minimum threshold value, the EGR valve controller 104 proceeds to step 205 to determine whether vehicle is in gear. If not, the method is reinitiated.
[0033] Referring to step 205, the EGR valve controller 104 determines whether vehicle is in transmission gear. If the vehicle is in gear, the EGR valve controller 104 proceeds to step 206 to determine whether brake pedal is pressed. If not, the method is reinitiated.
[0034] Referring to step 206, the EGR valve controller 104 coupled with the brake sensor 108 to determine whether brake pedal is pressed. After checking engine speed, vehicle speed, and gear engaged, the EGR valve controller checks the brake signal. Only when brake signal is true, i.e., brake pedal is in pressed condition, the EGR valve controller 104 enables the EGR cleaning cycle at step 207. If brake signal is false, i.e., the brake pedal is not in pressed condition, the method is reinitiated.
[0035] Referring to step 207, the EGR valve controller 104 enables the cleaning cycle of the EGR valve by operating the plurality EGR valve frequently in-between fully closed and fully open condition as shown in the figure 3.
[0036] Referring to step 208, the EGR valve controller 104 counts the number of cleaning cycle. The EGR valve controller 104 ensures that cleaning of EGR valve should not go beyond the predefined number of cycles. If number of cycles is equal to pre-defined threshold number of cycles, the EGR valve controller 104 moves on to next step. If not, the method is reinitiated.
[0037] Referring to step 209 and 210, after one complete cleaning cycle, timer counter get started and allow the EGR valve controller 104 to move in forward direction when pre-defined time is achieved. This timer provide time gap between two cleaning cycle, so that mechanical durability of EGR valve not get affected. The EGR valve controller 104 determines whether time period gap from last cleaning cycle is above the predetermined time period. If the time periods gap is above the predetermined time period, the method is reinitiated to perform another cleaning cycle of the EGR valve. If not, the method is stop until time period gas is greater than the predetermined timer period gap.
[0038] By the present method and system, it becomes easy to perform EGR valve cleaning cycle during vehicle is in running condition. One advantage achieved by the present method and system is that soot particles are cleaned periodically which avoids deposition of the same on the EGR valve. Therefore, the present method and system is a prevention method to avoid deposition of soot particles on the EGR valve.
[0039] Further, it is easy to build the present ECU and EGR valve control system with a plurality of sensors in the vehicle. The present system is cost efficient as compared to other existing solutions.
[0040] It will be further appreciated that functions or structures of a plurality of components or steps may be combined into a single component or step, or the functions or structures of one-step or component may be split among plural steps or components. The present invention contemplates all of these combinations. Unless stated otherwise, dimensions and geometries of the various structures depicted herein are not intended to be restrictive of the invention, and other dimensions or geometries are possible. Plural structural components or steps can be provided by a single integrated structure or step. Alternatively, a single integrated structure or step might be divided into separate plural components or steps. In addition, while a feature of the present invention may have been described in the context of only one of the illustrated embodiments, such feature may be combined with one or more other features of other embodiments, for any given application. It will also be appreciated from the above that the fabrication of the unique structures herein and the operation thereof also constitute methods in accordance with the present invention. The present invention also encompasses intermediate and end products resulting from the practice of the methods herein. The use of “comprising” or “including” also contemplates embodiments that “consist essentially of” or “consist of” the recited feature.
[0041] The term “vehicle” as used throughout this detailed description and in the claims refers to any moving vehicle that is capable of carrying one or more human occupants and is powered by any form of energy. The term “vehicle” is a motor vehicle which includes, but is not limited to: cars, trucks, vans, minivans, hatchback, sedan, MUVs, and SUVs.
[0042] Although embodiments for the present subject matter have been described in language specific to structural features, it is to be understood that the present subject matter is not necessarily limited to the specific features described. Rather, the specific features and methods are disclosed as embodiments for the present subject matter. Numerous modifications and adaptations of the system/component of the present invention will be apparent to those skilled in the art, and thus it is intended by the appended claims to cover all such modifications and adaptations which fall within the scope of the present subject matter.