Description:FIELD
The present disclosure relates to a system and a method for reducing NOx emissions in an automated manual transmission vehicle.
DEFINITIONS
As used in the present disclosure, the following term is generally intended to have the meaning as set forth below, except to the extent that the context in which it is used indicates otherwise.
MIDC: The term relates to an acronym for Modified Indian Driving Cycle and is used for assessing emissions from cars and LCVs. MIDC was adopted in the year 2000 and was later modified with a better cold start testing procedure. It is mostly the same as Europe’s NEDC (New European Driving Cycle), which is made up of four ECE-15 Urban Driving Cycles (UDC1) and an Extra-Urban driving cycle (EUDC2). However, the maximum speed in the MIDC cycle has been reduced to 90 km/h considering the Indian conditions.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
In case of a conventional manual transmission vehicle, gear shifting is executed in the sequence wherein foot is put off the accelerator pedal first, the clutch is pressed, gear shift is executed and eventually the accelerator is pressed, enabling the vehicle to move in the desired gear and speed. When a gear is shifted in a manual transmission mode, the catalytic converter of the vehicle is replenished with very limited mass of oxygen, the foot is lifted off from the accelerator and therefore, the catalytic converter will be in reduced oxygen environment, which aids reduction of NOx to Nitrogen gas and therefore, NOx emissions are reduced.
In the case of an Automated Manual transmission (AMT) vehicle during gear shifting, foot is not removed off the accelerator pedal. During gear shifting in an AMT vehicle, fuel to the engine is cut off for reducing the engine torque to zero before opening the clutch for gear shifting. During the fuel cut phase, the catalytic converter is replenished with oxygen leading to an oxygen rich environment. After the gear is shifted, fuel is reinstated to regain the engine torque, the oxides of nitrogen produced in the combustion chamber will not be substantially reduced to nitrogen and oxygen in the oxygen rich environment of the catalytic converter, leading to higher tail-pipe NOx emissions.
The process is explained in the form of chemical reactions as disclosed hereunder:
Reduction of nitrogen oxides into elemental nitrogen and oxygen is preferred in an oxygen deficit environment:
NOx → N2 + O2

Oxidation of carbon monoxide to carbon dioxide is preferred in an oxygen rich environment:
CO + O2 → CO2

Oxidation of hydrocarbons into carbon dioxide and water is preferred in an oxygen rich environment:
CnH2n+2+ O2 → CO2 + H2O

Thus, reduction of nitrogen oxides is not preferred in an oxygen rich environment, whereas oxidation of carbon or hydrocarbon is preferred in an oxygen rich environment.
Prior art discloses methods for reduction of NOx in an AMT vehicle during gear shifting but these methods compromise on the quality of gear shifting and the time of gear shifting. A prior art discloses a control system for a vehicle which performs torque down control to reduce torque of an engine by cutting off supply of fuel to at least one of the cylinders of the engine during an inertia phase of a power-on upshift. During the torque down control, the throttle opening is controlled to a relatively reduced extent in response to an amount of nitrogen oxide deposited on a catalyst in the exhaust system of the engine. To prevent the oxygen getting deposited on the catalytic converter and reducing the nitrogen oxide, the torque down phase increases the shift time. The prior art, therefore, compromises on the gear shift quality and gear shift time.
There is, therefore, felt a need to provide a system and a method for reducing NOx emissions in an AMT vehicle during gear shifting that mitigates the drawbacks mentioned hereinabove or at least provides a useful alternative.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
An object of the present disclosure is to ameliorate one or more problems of the background or to at least provide a useful alternative.
Another object of the present disclosure is to provide a system for reducing NOx emissions from AMT vehicles during gear shifting.
Another object of the present disclosure is to provide a system for creating oxygen deficit environment in the catalytic converter of an AMT vehicle during gear shifting.
Another object of the present disclosure is to provide a system for purging of a catalytic converter with a fuel during a gear shift in an AMT vehicle.
Another object of the present disclosure is to provide a system for reduction of NOx without compromising on quality of the gear shifting and time of the gear shifting in an AMT vehicle.
Another object of the present disclosure is to provide a system for reducing NOx during gear shifting substantially to the same range as NOx range when a gear is not shifted in the AMT vehicle.
Yet another object of the present disclosure is to provide a method for purging catalytic converter of an AMT vehicle during gear shifting for reducing NOx emissions in the AMT vehicle.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure relates to a system for reducing NOx emissions in an AMT vehicle having an engine, a throttle governing device, fuel metering system and a catalytic converter. The system comprises a means for purging of catalytic converter with a pre-determined amount of fuel during gear shifting for reducing NOx emissions to a pre-determined range.
The present disclosure also relates to a method for reducing NOx emissions in an AMT vehicle having an engine, a throttle governing device, a fuel metering system and a catalytic converter. In the AMT vehicle, the throttle is opened during gear shifting allowing purging of the catalytic converter with a pre-determined mass of fuel for reducing NOx emissions to a pre-determined range.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
The present disclosure will now be described with the help of the accompanying drawings, in which:
Figure 1 illustrates operation of the Transmission Control Unit (TCU) in accordance with the present disclosure;
Figure 2 illustrates workflow for the purging of catalytic converter to reduce NOx emissions in accordance with the present disclosure;
Figure 3 illustrates driver requested torque and the torque reduced to zero during gear shifting;
Figure 4 illustrates different stages of gear shifting in an AMT vehicle in accordance with the present disclosure;
Figure 5 illustrates fuel cut during the gear shifting and purging of catalytic converter in an AMT vehicle in accordance with the present disclosure;
Figure 6 illustrates NOx emissions in ppm (parts per million) during gear shifting without purging of catalytic converter in an AMT vehicle in accordance with the present disclosure;
Figure 7 illustrates NOx emissions reduction in ppm during gear shifting with purging of catalytic converter in an AMT vehicle in accordance with the present disclosure; and
Figure 8 illustrates catalytic converter purging during gear shift and depicts fuel cut off region and purging region in an AMT vehicle in accordance with the present disclosure.
LIST OF REFERENCE NUMERALS
100 AMT system
102 lever signals
104 engine RPM
106 transmission RPM
108 transmission control unit (TCU)
110 clutch actuators
112 shuttle shifting actuator
114 engine
116 clutch
118 manual transmissions
120 wheels
200 purging workflow
202 driver requests for torque
204 gear shifts through TCU
206 mass of air calculation
208 purging of catalytic converter
302 driver requested torque
304 gears
306 actual torque requested by TCU
308 gear shift region
402 phase 1-clutch opening
404 phase 2-gear shift
406 phase 3-clutch closing
502 integrated mass air
504 NOx emissions
506 gear shift time region
508 fuel cut region
510 catalytic converter purging region
602 vehicle speeds
802 oxygen level
804 fuel cut off
806 oxygen purging
808 fuel cut off region
810 purging region
DETAILED DESCRIPTION
Embodiments of the present disclosure will now be described with reference to the accompanying drawing.
Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms "a,” "an," and "the" may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms "comprises," "comprising," “including,” and “having,” are open ended transitional phrases and therefore specify the presence of stated features, integers, steps, operations, elements, modules, units and/or components, but do not forbid the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The particular order of steps disclosed in the method and process of the present disclosure is not to be construed as necessarily requiring their performance as described or illustrated. It is also to be understood that additional or alternative steps may be employed.
The terms first, second, third, etc., should not be construed to limit the scope of the present disclosure as the aforementioned terms may be only used to distinguish one element, component, region, layer or section from another component, region, layer or section. Terms such as first, second, third etc., when used herein do not imply a specific sequence or order unless clearly suggested by the present disclosure.
In case of a conventional manual transmission vehicle, in order to shift a gear, foot is put off the accelerator pedal, clutch is pressed, gear shift is executed and eventually the accelerator is pressed, enabling the vehicle to move in the desired gear and speed. In this sequence of gear shifting in a manual transmission mode, the catalytic converter of the vehicle during gear shifting is replenished with very less quantity of oxygen as the foot is lifted off from the accelerator. Therefore, the catalytic converter is in an oxygen deficit environment, which aids reduction of NOx to Nitrogen gas, resulting in reduced NOx emissions in the tailpipe.
In the case of an Automated Manual transmission (AMT) vehicle during gear shift the foot is not removed off the accelerator pedal when the speed is increased or decreased. During every gear shift in the AMT vehicle, fuel to the engine is cut off for reducing the engine torque to zero before opening the clutch for a gear shift. During the fuel cut phase, the catalytic converter is replenished with air leading to an oxygen rich environment. After the gear shift, fuel is reinstated to regain the engine torque. The oxides of nitrogen produced in the combustion chamber will not be substantially reduced to nitrogen and oxygen in the oxygen surplus environment of the catalytic converter, leading to higher tail-pipe NOx emissions.
The process is explained in the form of chemical reactions as disclosed hereunder:
Reduction of nitrogen oxides into elemental nitrogen and oxygen is preferred in an oxygen deficit environment:
NOx → N2 + O2

Oxidation of carbon monoxide to carbon dioxide is preferred in an oxygen rich environment:
CO + O2 → CO2

Oxidation of hydrocarbons into carbon dioxide and water is preferred in an oxygen rich environment:
CnH2n+2+ O2 → CO2 + H2O

Thus, reduction of nitrogen oxides to nitrogen and oxygen is not preferred in an oxygen rich environment, whereas oxidation of carbon or hydrocarbon is preferred in an oxygen rich environment.

NOx cannot, therefore, be substantially reduced to elemental nitrogen and oxygen in an oxygen rich environment.
Prior art discloses systems and methods for reduction of NOx in AMT vehicles, but they compromise on the quality of gear shifting and the time of gear shifting. A prior art discloses a control system for a vehicle which performs torque down control to reduce torque of an engine by cutting off supply of fuel to at least one of the cylinders of the engine during an inertia phase of a power-on upshift. During the torque down control, the throttle opening is controlled to a relatively reduced extent in response to an amount of nitrogen oxide deposited on a catalyst in the exhaust system of the engine. The prior art therefore, compromises on the gear shift quality and gear shift time.
The present disclosure provides a system and a method for reducing NOx emissions in an automated vehicle without compromising on the gear shift quality and gear shift time.
The present disclosure will now be described in detail with reference to figures 1 through figure 8. The present embodiment does not limit the scope and ambit of the present disclosure.
In an aspect, the present disclosure relates to a system for reducing NOx emissions in an AMT vehicle during gear shifting to a pre-determined level in an automated manual transmission vehicle having an engine, a throttle governing device, a fuel metering system and a catalytic converter. The system disclosed comprises a means for purging a catalytic converter with a pre-determined mass of fuel during gear shifting, allowing reduction of NOx to a pre-determined range during gear shifting. The AMT vehicle includes an engine, a catalytic converter, a throttle governing device and a fuel metering system, wherein said engine achieves a zero torque by cutting off the supply of fuel to the engine during gear shifting.
In an AMT vehicle, when a gear is shifted, fuel injection is stopped but air continues to enter the catalytic converter, rendering catalytic converter environment oxygen rich. Mass of air entering the catalytic converter during fuel cut stage is calculated by the equation given hereunder:
Mass of air entering the catalyst during fuel cut = integral [ml * (1/ ʎ - 1) * dT]
where, ml = exhaust mass flow (kg/h), ʎ - Air to fuel ratio and dT is infinitesimally small change in the independent variable time, t. The ratio is, generally, more than 16 during the stage when fuel is cut to the engine at the time of gear shifting.
The oxygen rich environment or the lean environment in a catalytic converter is unsuitable for reducing NOx to nitrogen and oxygen.
During catalytic converter purging, a decrement in the fuel dependent integral value is observed denoting that the oxygen in the catalytic converter is balanced by the fuel. The gravimetric mass of oxygen in the air is 23.2%, the equation hereinabove is modified as hereunder to incorporate the gravimetric mass of oxygen in the air:
Mass of oxygen stored in [mg O2] = Integral [ml (kg/h) * 0.232 * (1/ ʎ - 1) * dT]
The equation allows calculating mass of oxygen present in the catalytic converter at the time of gear shifting, from which mass of fuel required for purging is calculated.
In accordance with the present disclosure, the system allows purging of calculated amount of fuel during gear shifting for reducing NOx emissions to a pre-determined range during gear shifting.
In accordance with the present disclosure, the method allows purging of calculated amount of fuel during gear shifting for reducing NOx emissions to a pre-determined range during gear shifting.
In an embodiment of the present disclosure, NOx emissions during gear shifting in an AMT vehicle are reduced to the same range when a gear shift is not affected in the AMT vehicle.
In an exemplary embodiment of the present disclosure, NOx emissions without purging of the catalytic converter of an AMT vehicle, % margin of NOx reduction is 21.27%, indicating that reduction of NOx to nitrogen and oxygen is marginal.
In another exemplary embodiment, when the catalytic converter of an AMT vehicle is purged with fuel, there is a 34.87% margin improvement in the reduction of NOx.
In an exemplary embodiment of the present disclosure, 17% improvement in NOx emission margin in MIDC emission cycle is observed with catalyst purging during gear shifting when compared to the system without catalyst purging during gear shifting.
In accordance with the present disclosure, the integrated mass air flow passing through the catalytic converter during the AMT gear shift is calculated based on the length of the fuel cut. Based on the amount of the air present in the catalytic converter, the amount of fuel required for purging is decided. This allows the catalytic converter to be purged with a calculated amount of fuel during gear shifting of the AMT vehicle for reducing NOx emissions.
The catalytic converter of an AMT vehicle is purged with fuel during gear shifting by holding the throttle opening of an engine open, allowing catalytic converter to be purged during every gear shift of the AMT vehicle for reducing NOx emissions to a pre-determined level.
In accordance with the present disclosure, figure 1 depicts the AMT transmission system, having transmission control unit (TCU) which controls the hydraulic or electric actuators to operate the clutch and shift gears. The gearshift patterns are pre-programmed on the Electronic Control Unit (ECU) and works mainly depending on the engine operating speed and load as per the information received from the ECU. Once the system gauges optimal operating conditions, the TCU (108) engages the actuators which operate the clutch and gearbox.
In accordance with the present invention, figure 2 illustrates driver requested torque to maintain the specific speed of the AMT vehicle. TCU (108) sends the torque request to be honored by the ECU during the three phases of gear shift, as the requested torque is honored by the ECU and the TCU engages the actuators which operate the clutch and gearshift. Based on the torque request received from the driver in the AMT vehicle, gear shift request (204) is received from the TCU (108). To honor the torque request, the actual engine torque is reduced to zero during gear shifting. During the gear shifting, the engine management system stops the fuel but airflow to the catalytic converter is not cut off in line with the driver request (in an AMT vehicle, the driver’s foot is not lifted off the accelerator). The mass of air entering the catalytic converter during gear shifting is calculated (206). Having calculated the mass of air entering the catalytic converter during gear shifting, mass of fuel required for purging of the catalytic converter is calculated and catalytic converter is purged accordingly (208), allowing reduction of NOx emissions during gear shifting. The actual torque is reduced to zero during gear shifting.
In accordance with the present disclosure, figure 3 depicts the torque requested by the driver (302) while the vehicle is running. In an exemplary embodiment, driver requested torque (302) is maintained constant at 70Nm, whereas the actual torque requirement requested by the TCU is depicted by the line (306). During gear shifting to enable smooth shifting of gears, torque is reduced to zero as dictated by TCU (108), maintaining throttle pedal constant during the gear shifting. Figure 3 also indicates various gears (304) in which the vehicle is running.
In accordance with the present disclosure, figure 4 illustrates in more detail the stages of gear shifting in an AMT vehicle. X-axis represents time scale in seconds and Y-axis represents gear shifting in the AMT vehicle. The stages of gear shift include, clutch opening (402), gear shift (404) and clutch closing (406). Complete process of gear shifting is depicted as a gear shift region (308), in which the gear shifting from lower level to higher level or vice versa is accomplished. During gear shift the driver requested torque (302) and the actual torque requested (306) by the TCU (108) to engine management system is maintained appropriately to reduce the torque to zero and shift the gear. In the exemplary embodiment illustrated in figure 4, the gear opening phase starts at time interval of 451.075 and the actual gear shifting is accomplished at time 452.695.
Figure 5 illustrates catalytic converter purging in an oxygen surplus environment. Conventionally, in an AMT vehicle during gearshift the foot is not removed off the accelerator pedal. This causes very high mass of oxygen to be stored in the catalytic converter leading to an oxygen surplus environment. In accordance with the present invention, the fuel is introduced into the catalytic converter allowing consumption of the oxygen stored in the catalytic converter during gear shifting.
In the exemplary embodiment of the present disclosure, integrated mass air (502) enters into catalytic converter at a time of 485.358. Driver requested torque (302) and actual torque requested (306) by the TCU (108) is also indicated. During this gear shift time phase (506) the engine management system stops the fuel flow in a stepwise manner to take the engine torque to zero before clutch opening for gear shifting, and at the same time during the fuel cut off region (508) air accumulates in the catalytic converter which creates an oxygen surplus environment. The length of the fuel cut region (508) allows calculating a mass of air accumulated in the catalytic converter. In accordance with the present invention, catalytic purging consumes the mass of air present in the catalytic converter. During the catalytic purging, the fuel is reinstated for consuming the air stored in the catalytic converter and to regain the engine torque. Further, Figure 5 illustrates the NOx emissions (504) during the purging of catalytic converter. In the embodiment of the present disclosure, NOx emissions are controlled and maintained within 5 ppm (parts per million) during gear shifting.
The present disclosure also draws a comparison between conventionally operated AMT vehicle without catalytic converter purging and the AMT vehicle with catalytic converter purging in accordance with the present disclosure.
In accordance with the present disclosure, X-axis of the figure 6 represents time scale and Y axis represents NOx emissions in ppm, gear shifting and vehicle speed in km/h in an AMT equipped vehicle. Figure 6 illustrates typically an AMT vehicle that is not configured for catalytic converter purging for reducing the NOx emission during gear shifting, therefore, in absence of catalytic converter purging the NOx emission increased and are typically in the range of 15-20 ppm. Further, as catalytic converter purging is absent in the AMT vehicle the oxygen surplus environment reduces the efficiency of NOx emission reduction process and leads to higher tail-pipe NOx emissions, in the region of 15-20 ppm.
In an exemplary embodiment as illustrated in figure 6 of the present disclosure, in the conventional AMT vehicle during gear shifting at time of 472.90 and 485.21 seconds, the NOx emissions (504) increase and are in the range of 15-20 ppm. Therefore, to reduce the NOx emission in said oxygen surplus environment, the present disclosure provides the catalytic converter purging to alleviate the problem associated with integrated mass air flow during gear shift and NOx emission.
In accordance with the present disclosure, figure 7 illustrates the AMT vehicle, wherein catalytic converter is purged with fuel. In an embodiment of the present invention and as illustrated in figure 7, NOx emissions (504) are maintained within 5 ppm and is maintained in the same range when the vehicle is running and gear is not shifted. It is observed that NOx emissions (504) are in a constant range throughout the time period of 465 to 500 even though gears are shifted (304). Figure 7 illustrates in between the gear shift time of 477.37 and 489.00, NOx emissions are maintained in the same range as in the case when a gear is not shifted. Maintenance of NOx emissions in the same range during gear shifting as the NOx emissions when gear is not shifted, is achieved by purging (510) of the catalytic converter during gear shifting.
In accordance with the present disclosure, figure 8 depicts the catalytic converter purging during gear shift. X-axis of the figure 8 represents the air mass flow integral at cylinder cut during the gear shifting and Y-axis represents the initial value for mass air flow integral for catalytic converter purging after cylinder cut during gear shift phase. The fuel cut region (808) allows calculating initial value for mass air flow integral for catalytic purging after cylinder cut which is calibratable and is finalized after its effect in NOx emissions. Based on the calibrated value of mass air flow integral, fuel mass to be used for purging is calculated and is represented by the purging region (810).
The foregoing description of the embodiments has been provided for purposes of illustration and is not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment, but, are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.
The present disclosure is further described in light of the following experiments which are set forth for illustration purpose only and not to be construed for limiting the scope of the disclosure. The following experiments can be scaled up to industrial/commercial scale and the results obtained can be extrapolated to industrial scale.
EXPERIMENTAL DETAILS
NOx emissions tests were conducted in an AMT vehicle during gear shifting. NOx emissions test was conducted in a conventional AMT vehicle without purging of the catalytic converter. The test results are tabulated hereunder in table 1.
Table 1: Emissions test result for AMT vehicle without catalyst purge during gearshift.
Weighted Result DF (Deterioration factor) Result
w. DF standard % Margin
HC [mg/km] 18.676 1.3 24.2792 100.0 75.72
NMHC [mg/km] 16.161 1.3 21.0098 68.0 69.10
NOx [mg/km] 29.525 1.6 47.2405 60.0 21.27
CO [mg/km] 102.095 1.5 153.1425 1000.0 84.69

NOx emissions test was conducted in the AMT vehicle with catalytic converter purging in accordance with the present disclosure. The test results are tabulated hereunder in table 2.
Table 2: Emissions test result for AMT vehicle with catalyst purge during gearshift.
Weighted Result DF (Deterioration factor) Result
w. DF standard % Margin
HC [mg/km] 24.460 1.3 31.798 100.0 68.20
NMHC [mg/km] 20.904 1.3 27.175 68.0 60.04
NOx [mg/km] 24.425 1.6 39.080 60.0 34.87
CO [mg/km] 181.448 1.5 272.173 1000.0 72.78

It was observed from the table 1 and table 2 that the reduction of NOx emissions is improved in the AMT vehicle wherein catalytic converter was purged during gear shifting in comparison to the AMT vehicle wherein catalytic converter purging was not carried out. It was observed that the percentage of margin was improved from 21.27 % to 34.87%. The mass of fuel with which the catalytic converter was purged was calculated from the mass of air entering the catalytic converter during gear shifting. DF refers to deterioration factor.
TECHNICAL ADVANCEMENTS
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of a system and a method for reduction of NOx in an AMT vehicle during gear shifting that
• reduces NOx below 5 ppm and thus contributes to the reduction of hazardous emissions from the vehicle; and
• does not compromise on the gear shift time and gear shift quality.

The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the invention to achieve one or more of the desired objects or results. While certain embodiments of the inventions have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Variations or modifications to the formulation of this invention, within the scope of the invention, may occur to those skilled in the art upon reviewing the disclosure herein. Such variations or modifications are well within the spirit of this invention.
The numerical values given for various physical parameters, dimensions and quantities are only approximate values and it is envisaged that the values higher than the numerical value assigned to the physical parameters, dimensions and quantities fall within the scope of the invention unless there is a statement in the specification to the contrary.
While considerable emphasis has been placed herein on the specific features of the preferred embodiment, it will be appreciated that many additional features can be added and that many changes can be made in the preferred embodiment without departing from the principles of the disclosure. These and other changes in the preferred embodiment of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation. , Claims:WE CLAIM:

1. A system for reducing NOx emissions (504) in an AMT vehicle (100) having an engine (114), a throttle governing device, a fuel metering system and a catalytic converter; said system comprising a means for purging the catalytic converter during a gear shifting (304) with a pre-determined amount of fuel for reducing NOx emissions (504) to a pre-determined range during gear shifting (304).
2. The system for reducing NOx emissions (504) in an AMT vehicle (100) as claimed in claim 1, wherein the purging (510) of catalytic converter comprises supplying a pre-determined mass of fuel to the catalytic converter during gear shifting (304).
3. The system for reducing NOx emissions (504) in an AMT vehicle (100) as claimed in claim 2, wherein the predetermined mass of fuel is supplied by the fuel metering system to the catalytic converter of the AMT vehicle (100) during gear shifting (304).
4. The system for reducing NOx emissions (504) in an AMT vehicle (100) as claimed in claim 3, wherein the pre-determined mass of fuel for purging (510) of catalytic converter is calculated from the mass of air (502) entering the catalytic converter during gear shifting (304) in the AMT vehicle (100).
5. The system for reducing NOx emissions (504) in an AMT vehicle (100) as claimed in claim 1, wherein due to the purging of the catalytic converter the pre-determined range of NOx emissions (504) during gear shifting (304) in the AMT vehicle (100) is substantially same as the range of NOx emissions (504) when a gear is not shifted in the AMT vehicle (100).
6. The system for reducing NOx emissions (504) in an AMT vehicle (100) as claimed in claim 1, wherein the purging (510) of the catalytic converter during gear shifting (304) creates oxygen deficit environment, promoting reduction of NOx emissions (504) to nitrogen and oxygen.
7. A system for reducing NOx emissions (504) in an AMT vehicle (100) as claimed in claim 5, wherein NOx emissions (504) are reduced to less than 5ppm.
8. A method for reducing NOx emissions (504) in an AMT vehicle (100) having an engine (114), a throttle governing device, a fuel metering system and a catalytic converter, wherein the throttle is opened during gear shifting (304) allowing purging (510) of catalytic converter with a pre-determined mass of fuel for reducing NOx emissions (504) to a pre-determined range.
9. The method for reducing NOx emissions (504) in the AMT vehicle (100) as claimed in claim 8, wherein the mass of fuel for purging (510) of catalytic converter is arrived at after calculating the mass of air (502) entering the catalytic converter during gear shifting (304).
10. The method for reducing NOx emissions (504) in the AMT vehicle (100) as claimed in claim 8, wherein the pre-determined range of NOx emissions (504) during gear shifting (304) in an AMT vehicle (100) is substantially same as the NOx emissions (504) when a gear is not shifted in the AMT vehicle (100).
11. The method for reducing NOx emissions (304) in the AMT vehicle (100) as claimed in claim 8, wherein the flow of purging fuel is actuated after a gear shift (304) and the fuel supply is stopped in the AMT vehicle (100).
12. The method for reducing NOx emissions (504) in the AMT vehicle (100) as claimed claim 8, wherein purging (510) of catalytic converter during gear shifting (304) creates oxygen deficit environment, promoting reduction of NOx emissions (504) to nitrogen and oxygen.
13. The method for reducing NOx emissions (504) in the AMT vehicle (100) as claimed in claim 8, wherein NOx emissions (504) are reduced to less than 5 ppm.
14. The method for reducing NOx emissions (504) in the AMT vehicle (100) as claimed in claim 8, wherein the mass of fuel for purging (510) of the catalytic converter is calculated from the mass of air (502) entering the catalytic converter during gear shifting (304).
Dated this 05th day of June, 2023

_______________________________
MOHAN RAJKUMAR DEWAN, IN/PA – 25
of R.K.DEWAN & CO.
Authorized Agent of Applicant

TO,
THE CONTROLLER OF PATENTS
THE PATENT OFFICE, AT CHENNAI