1. A method for controlling fluid flow parameters for an engine (1), comprising: computing, by a first estimator (3) associated to a control unit (2), at least one of an intake pressure or an exhaust pressure of the engine (1); computing, by a second estimator (4) associated with the control unit (2), at least one of an intake temperature or an exhaust temperature of the engine (1), wherein the second estimator (4) determines engine volumetric efficiency based on the at least one of the intake temperature or the exhaust temperature of the engine (1); determining, by the first estimator (3), an Exhaust Gas Re-circulation (EGR) flow rate for the engine (1) based on the computed engine volumetric efficiency and the at least one of the intake pressure or the exhaust pressure; determining, by the second estimator (4), a cylinder mass flow rate based on the computed Exhaust Gas Re-circulation (EGR) flow rate and the at least one of the intake temperature and the exhaust temperature; operating, by the control unit (2), an Exhaust Gas Re-circulation (EGR) valve (5) in fluid communication with an intake manifold (6) of the engine (1) to allow Exhaust Gas Re-circulation (EGR) flow corresponding to the Exhaust Gas Re-circulation (EGR) flow rate into the intake manifold (6); and operating, by the control unit (2), a throttle body (7) in fluid communication with the intake manifold (6), to allow air flow into the engine (1) corresponding to the cylinder mass flow rate, thereby controlling the inlet flow parameters of the engine (1).

2. The method as claimed in claim 1, comprises receiving, by the control unit (2), a plurality of operating parameters of the engine (1).

3. The method as claimed in claim 2, wherein the plurality of operating parameters of the engine (1) include: a mass air flow into the engine (1), measured by a mass air flow (MAF) sensor (12); temperature of exhaust gas, measured by an EGR temperature sensor (13); engine speed, measured by an engine speed sensor (15); intake manifold pressure, measured by a temperature manifold absolute pressure (TMAP) sensor (14); engine volumetric efficiency retrieved from a memory unit associated to the control unit (2), wherein the mass air flow (MAF) sensor (12), the temperature sensor, the speed sensor and the temperature manifold absolute pressure (TMAP) sensor are communicatively connected to the control unit (2).

4. A system (100) for controlling inlet flow parameters of an engine (1), the system (100) comprising: a first estimator (3) associated with a control unit (2) and configured to: compute, at least one of an intake pressure or an exhaust pressure of the engine (1), based on the plurality of operating parameters; determine Exhaust Gas Re-circulation (EGR) flow rate based on the engine volumetric efficiency computed by a second estimator (4) and the at least one of intake pressure or the exhaust pressure; the second estimator (4) associated with the control unit (2) and configured to: compute, at least one of an intake temperature or an exhaust temperature of the engine (1); determine, engine volumetric efficiency based on the at least one of intake temperature or the exhaust temperature; determine, a cylinder mass flow rate based on the computed Exhaust Gas Re-circulation (EGR) flow rate and the at least one of intake temperature or the exhaust temperature; wherein, the control unit (2) operates an Exhaust Gas Re-circulation (EGR) valve (5) in fluid communication with an intake manifold (6) of the engine (1) to allow Exhaust Gas Re-circulation (EGR) flow into the intake manifold (6) corresponding to the Exhaust Gas Re-circulation (EGR) flow rate, and operates a throttle body (7) in fluid communication with the intake manifold (6), to allow charge flow into the engine (1) corresponding to the cylinder mass flow rate, thereby controlling the fluid flow parameters of the engine (1).

5. The system (100) as claimed in claim 4, wherein the control unit (2) is configured to receive a plurality of operating parameters of the engine (1).

6. The system (100) as claimed in claim 4, comprises a mass air flow (MAF) sensor (12) positioned upstream of the throttle body (7), to measure mass air flow into the engine (1).

7. The system (100) as claimed in claim 4, comprises an EGR temperature sensor (13) positioned upstream of the Exhaust gas Re-circulation (EGR) valve (5), to measure temperature of exhaust gas.

8. The system (100) as claimed in claim 4, comprises an engine speed sensor (15) positioned in the engine (1), to measure engine speed.

9. The system (100) as claimed in claim 4, comprises a temperature manifold absolute pressure (T-MAP) sensor (14) positioned in the intake manifold (6), to measure intake manifold pressure.

10. The system (100) as claimed in claim 4, comprises a memory unit associated to the control unit (2), configured to store the plurality of operating parameters of the engine (1).

11. The system (100) as claimed in claim 4, wherein the mass air flow (MAF) sensor (12), the EGR temperature sensor (13), the engine speed sensor (15) and the temperature manifold absolute pressure (TMAP) sensor (14) are communicatively connected to the control unit (2).

12. A vehicle comprising a method for controlling fluid flow parameters for an engine (1) as claimed in claim 1.

13. A vehicle comprising a system (100) for controlling fluid flow parameters for an engine (1) as claimed in claim 4. , Description:TECHNICAL FIELD Present disclosure relates to a vehicle. Particularly, embodiments of the disclosure relate to air-fuel ratio control systems for the vehicle. Embodiments of the disclosure further relate to a method for controlling fluid flow parameters for an engine of the vehicle. BACKGROUND OF THE DISCLOSURE Conventional internal combustion engines [IC Engines], operate by drawing in air-fuel mixture into its cylinders. The air-fuel mixture combusted in the IC engine is used to drive the crankshaft and generate power. The combusted air-fuel mixture residues exhaust gases and are exhausted out from the IC engine to atmosphere. The exhaust gases from the IC engine contains toxic substances such as carbon dioxide, carbon monoxide, Mono-Nitrogen oxides (NOx) and the like, which pollute the atmosphere. Therefore, according to the environmental norms, stringent emission regulations are enforced to vehicle manufacturers to restrict the amount of toxic exhaust gases released into the atmosphere or the environment from the IC engines. However, at the same time, consumers are also demanding engines with higher efficiency, without compromise in its performance. Hence, two-predominant requirements that vehicle manufacturers need to satisfy are, emission control norms and efficient IC Engines. Advent of modern technology, has produced advanced combustion strategies or techniques to the existing design of IC engines. The combustion strategies or techniques control the amount of fuel or air mixture to be inlet into the engine, based on operating conditions of the engine. One such strategy or technique of combustion is Exhaust Gas-Recirculation [EGR]. In EGR, a portion of the exhaust gas is recirculated back into the engine. The recirculated exhaust gas may contain traces of unburnt fuel and therefore, this configuration reduces the amount of fuel drawn into the engine. Consequently, improving efficiency of the engine and satisfying the emission regulations. To implement, EGR configuration in the engines, several control techniques, known as EGR estimation methods are devised. The control techniques are configured to estimate the amount of exhaust gas that must be inlet into the engine for optimum combustion, based on several parameters such as power demand, operating temperature and the like. To determine operating parameters of the engine, several sensors are configured at predetermined locations. These sensors provide data to a control unit in real-time for estimation of exhaust gas flow rate into the engine. However, this involves use of various sensors, particularly a differential pressure sensor for providing feedback to the control unit. The differential pressure sensor is provided to monitor the exhaust gas pressure of the engine. At pressure conditions below a predetermined limit, the differential pressure sensor, is incapable of detecting pressure of the exhaust gas. Thus, at exhaust gas pressure below a predetermined limit, the value received by the control unit from the differential pressure sensor is erroneous or inaccurate. This inherently results in incorrect estimation of fuel or air mixture into the engine, leading to improper combustion, inefficiency and abrupt combustion of fuel within the IC engine. To overcome the aforesaid problem, additional sensors may be provided for accurate detection of pressure, even at lower pressure conditions. However, use of additional sensors significantly makes the system costly, complex and cumbersome. The present disclosure is directed to overcome one or more limitations stated above. The information disclosed in this background of the disclosure section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art SUMMARY OF THE DISCLOSURE One or more shortcomings of conventional assemblies are overcome and additional advantages are provided through the provision of an assembly as claimed in the present disclosure. Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure. In one non-limiting embodiment of the present disclosure, a method for controlling fluid flow parameters for an engine is disclosed. The method comprising computing by a first estimator associated to a control unit, at least one of an intake pressure or an exhaust pressure of the engine. A second estimator associated with the control unit, computes at least one of an intake temperature or an exhaust temperature of the engine. The second estimator determines engine volumetric efficiency based on the at least one of an intake temperature or an exhaust temperature of the engine. The first estimator determines an Exhaust Gas Re-circulation (EGR) flow rate for the engine based on the computed engine volumetric efficiency and the at least one of the intake pressure or the exhaust pressure. The second estimator determines a cylinder mass flow rate based on the computed Exhaust Gas Re-circulation (EGR) flow rate and the at least one of intake temperature and the exhaust temperature. The control unit, operates an Exhaust Gas Re-circulation (EGR) valve in fluid communication with an intake manifold of the engine to allow Exhaust Gas Re-circulation (EGR) flow at the determined rate into the intake manifold. The control unit operates a throttle body in fluid communication with the intake manifold, to allow air flow into the engine, based on the computed cylinder mass flow rate, thereby controlling the inlet flow parameters of the engine. In an embodiment, the control unit receives a plurality of operating parameters of the engine. In an embodiment, the plurality of operating parameters of the engine include a mass air flow through the engine, measured by a mass air flow (MAF) sensor. Also, temperature of exhaust gas, measured by a temperature sensor and engine speed, measured by a speed sensor. Additionally, intake manifold pressure, is measured by a temperature manifold absolute pressure (T-MAP) sensor and engine volumetric efficiency retrieved from a memory unit associated to the control unit. The mass air flow (MAF) sensor, temperature sensor, speed sensor and temperature manifold absolute pressure (T-MAP) sensor are associated to the control unit. In an embodiment, a system for controlling inlet flow parameters for an engine is disclosed. The system comprising a first estimator associated with a control unit. The first estimator is configured to compute, at least one of an intake pressure or an exhaust pressure of the engine, based on the plurality of operating parameters. The first estimator further determines Exhaust Gas Re-circulation (EGR) flow rate based on the engine volumetric efficiency computed by a second estimator and the intake pressure estimate. The second estimator is associated with the control unit and is configured to compute, at least one of an intake temperature estimate of the engine, compute engine efficiency based on the intake temperature or an exhaust temperature. Lastly, to determine a cylinder mass flow rate based on the computed Exhaust Gas Re-circulation (EGR) flow rate and the at least one of the intake temperature and the exhaust temperature. The control unit operates an Exhaust Gas Re-circulation (EGR) valve in fluid communication with an intake manifold of the engine to allow computed Exhaust Gas Re-circulation (EGR) flow into the intake manifold, and operates a throttle body in fluid communication with the intake manifold, to allow charge flow into the engine based on the computed cylinder mass flow rate, thereby controlling the fluid flow parameters of the engine. In an embodiment, a mass air flow (MAF) sensor is positioned upstream of the throttle body, to measure mass air flow into the engine. In an embodiment, a temperature sensor is positioned upstream of the Exhaust gas Re-circulation (EGR) valve to measure temperature of exhaust gas. In an embodiment, a speed sensor is positioned in the engine to measure engine speed. In an embodiment, a temperature manifold absolute pressure (T-MAP) sensor is positioned in the intake manifold, to measure intake manifold pressure. In an embodiment, a memory unit associated to the control unit is provided and configured to store plurality of operating parameters of the engine. In an embodiment, the mass air flow (MAF) sensor, temperature sensor, speed sensor and temperature manifold absolute pressure (T-MAP) sensor are communicatively connected to the control unit. It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined together to form a further embodiment of the disclosure. The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description. BRIEF DESCRIPTION OF DRAWINGS The novel features and characteristic of the disclosure are set forth in the appended claims. The disclosure itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings. One or more embodiments are now described, by way of example only, with reference to the accompanying drawings wherein like reference numerals represent like elements and in which: Figure 1 illustrates a block diagram of a system for controlling fluid flow parameters for an engine, in accordance with an exemplary embodiment of the present disclosure. Figure 2 illustrates a block diagram of a first estimator and a second estimator configured in the system of Figure 1, in accordance with an exemplary embodiment of the present disclosure. Figure 3 illustrates process flow chart of the first estimator, in accordance with an embodiment of the present disclosure. Figure 4 illustrates process flow chart of the second estimator, in accordance with an embodiment of the present disclosure. Figures 5 illustrates graphical representation of a signal generated by the first estimator and the second estimator, in accordance with an embodiment of the present disclosure. Figure 6 illustrates graphical representation of a torque curve, in accordance with an embodiment of the present disclosure. Figure 7 illustrates graphical representation of an EGR flow rate curve, in accordance with an embodiment of the present disclosure. The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily 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. DETAILED DESCRIPTION While the embodiments in the disclosure are subject to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the figures and will be described below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the scope of the disclosure. It is to be noted that a person skilled in the art would be motivated from the present disclosure a method for controlling fluid flow parameters of an engine, which may vary based on configuration of the engine. However, such modifications should be construed within the scope of the disclosure. Accordingly, the drawings show only those specific details that are pertinent to understand the embodiments of the present disclosure, so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein. The terms “comprises”, “comprising”, or any other variations thereof used in the disclosure, are intended to cover a non-exclusive inclusion, such that a device, system, assembly that comprises a list of components does not include only those components but may include other components not expressly listed or inherent to such system, or assembly, or device. In other words, one or more elements in a system or device proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or device. Embodiments of the disclosure discloses, a method for controlling fluid flow parameters for an engine. The method includes computing an intake pressure of the engine by a first estimator and an intake temperature of the engine by a second estimator, wherein the first estimator and the second estimator are associated with the control unit. The second estimator determines engine volumetric efficiency, based on the determined intake temperature. The first estimator determines an Exhaust Gas Re-circulation (EGR) flow rate for the engine, based on the computed engine volumetric efficiency and the intake pressure estimate. The second estimator determines a cylinder mass flow rate based on the computed Exhaust Gas Re-circulation (EGR) flow rate and the intake temperature estimate. The control unit operates an Exhaust Gas Re-circulation (EGR) valve in fluid communication with an intake manifold of the engine, to allow Exhaust Gas Re-circulation (EGR) flow at a determined rate into the intake manifold. The control unit operates a throttle body in fluid communication with the intake manifold, to allow air flow into the engine based on the computed cylinder mass flow rate, thereby controlling the inlet flow parameters of the engine. The present disclosure further provides a system for controlling fluid flow parameters of the engine. The system includes the first estimator and the second estimator, associated with the control unit. The first estimator is configured to compute, an intake pressure estimate of the engine, based on the plurality of operating parameters. The first estimator, determines Exhaust Gas Re-circulation (EGR) flow rate based on the engine volumetric efficiency computed by the second estimator and the intake pressure estimate. The second estimator is associated with the control unit and is configured to compute, an intake temperature estimate of the engine, engine volumetric efficiency based on the intake temperature estimate and determine, a cylinder mass flow rate based on the computed Exhaust Gas Re-circulation (EGR) flow rate and the intake temperature estimate. The control unit operates an Exhaust Gas Re-circulation (EGR) valve in fluid communication with an intake manifold of the engine to allow computed Exhaust Gas Re-circulation (EGR) flow into the intake manifold. The control unit, operates a throttle body in fluid communication with the intake manifold, to allow charge flow into the engine based on the computed cylinder mass flow rate, thereby controlling the fluid flow parameters of the engine. The following paragraphs describe the present disclosure with reference to Figures 1 to 7. In the Figures, the same element or elements which have similar functions are indicated by the same reference signs. Figure 1 is an exemplary embodiment of the present disclosure, which illustrates a system (100) for controlling fluid flow parameters for an engine (1). The system (100) includes a control unit (2) configured to control operations of the engine (1). The engine (1) includes at least one cylinder (8) in fluid communication with a throttle body (7) and an intake manifold (6) for receiving air-fuel mixture. The throttle body (7) may include a first throttle valve (7a) and a second throttle valve (7b). A Mass-Air Flow (MAF) sensor (12) is provided upstream of the first throttle valve (7a), for measuring the amount of air flowing from the first throttle valve (7a) via an air filter (22). The metered air is inlet into a compressor (9) of a turbocharger (10) of the engine (1), for pressurising the air. The engine (1) as illustrated in figure 1 includes an Exhaust Gas Re-circulation (EGR) system (200) connected to an exhaust manifold (19) via a catalytic converter (11) of the engine (1), for routing exhaust gas. The exhaust gas is routed to a turbine (18), for operating the compressor (9) before releasing the exhaust gas to atmosphere. The EGR system (200) includes an EGR valve (5) and an EGR cooler (20) in fluid communication with the compressor (9), for routing part of the exhaust gas into the compressor (9). An EGR temperature sensor (13) is configured upstream of the EGR valve (5) to measure temperature of the exhaust gas routed from the engine (1). The compressor (9) is further configured to pressurise air and exhaust gas mixture from the EGR valve (5), before inletting into an intake manifold (6) via an intercooler (21). The intake manifold (6) includes a Temperature Manifold Absolute Pressure (TMAP) sensor (14), for measuring the temperature and pressure of air-fuel mixture [hereinafter referred to as charge] is inlet into the engine (1). The intake manifold (6) is in fluid communication with the second throttle valve (7b), for controlling the charge flow into the engine (1). The engine (1) also includes an engine speed sensor (15) for measuring the speed of rotation of a crankshaft in the engine (1). The control unit (2) is interfaced to each of the TMAP sensor (14), the MAF sensor (12), the EGR temperature sensor (13), the engine speed sensor (15), the first throttle body (7a) and the second throttle body (7b) for controlling operation of the engine (1). The control unit (2) also includes a memory unit, for storing data pertaining to an engine volumetric efficiency. In an embodiment, the memory unit is selected from group such as but not limiting to RAM, ROM …etc. which serves the purpose of storing data. Referring to figure 2, a first estimator (3) and a second estimator (4) are associated with the control unit (2). In an embodiment, the first estimator (3) and the second estimator (4) are configured in the control unit (2). The first estimator (3) and the second estimator (4) may be configured to receive input data from each of the TMAP sensor (14), the MAF sensor (12), the EGR temperature sensor (13) and the engine speed sensor (15) [hereinafter referred to as engine operation parameter sensors]. The first estimator (3) may be configured to compute at least one of inlet pressure of the charge or an exhaust pressure of the engine (1), based on the data received from each of the sensors. The first estimator (3) may be configured to determine, Exhaust Gas Re-circulation (EGR) flow rate into the at least one cylinder (8), based on the data received by the first estimator (3) and the computed inlet pressure or the exhaust pressure. The second estimator (4) is interfaced to the first estimator (3) and is configured to compute at least one of inlet temperature or an exhaust temperature of the engine (1), based on the data received from each of the engine operation parameter sensors. The second estimator (4) determines, engine volumetric efficiency based on the data received by the first estimator (3) and the computed inlet temperature or the exhaust temperature of the engine (1). The data computed by the first estimator (3) and the second estimator (4) are collated to determine a cylinder mass flow rate. In an embodiment, the cylinder mass flow rate may be the amount of the charge that is inlet into the at least one cylinder (8), based on the operating parameters. In an embodiment, the engine volumetric efficiency may be procured from a calibrated engine dynamometer, while operating the engine (1) at predetermined conditions including, but not limited to, power demand, air-fuel ratio, inlet temperature and pressure, outlet pressure and temperature and the like. In an embodiment, the control unit (2) may be configured to store in the memory unit, data received from the sensors interfaced to the engine (1). In an embodiment, the first estimator (3) may be a sliding mode estimator. In another embodiment, the first estimator (3) may be a processing unit, associated to the control unit (2) for computing the EGR flow rate for the engine (1). In an embodiment, the second estimator (4) may be a sliding mode estimator. In another embodiment, the second estimator (4) may be a processing unit, configured for computing the cylinder mass flow rate for the engine (1). In an exemplary embodiment, the sliding mode estimator of the first estimator (3) and the second estimator (4) operates based on a discrete time equation, which is arrived at as follows: …………………………………… (Eq. 1) The sliding surface are chosen as ………………….. (Eq. 2) and ……………… (Eq. 3) The inputs for Eq. 2 and Eq. 3 are ………………….. (Eq. 4) …………………………. (Eq. 5) Wherein, is the derivative of Eq. 4 by Euler’s differentiation method. In an exemplary embodiment, value of ?=1.5 and ?=1.1 may be tuned further is the suprimal value of second derivative of the signal. In another embodiment, the value may also be a large value [1e5] and may be later reduced to a reasonable value by tuning. From sliding mode estimator, the value of inlet pressure and inlet temperature can be obtained. This is done by using equations Eqs. 1-5, and substituting F(k) with and separately. Thus, there are two estimations one for pressure parameter [or pressure dynamics] and other for temperature parameter [or temperature dynamics]. In an embodiment, there are two sliding model algorithms operating simultaneously for determining EGR flow rate and cylinder mass flow rate. Figure 3, in one exemplary embodiment of the present disclosure, illustrates a process flowchart of the first estimator (3), for estimating the EGR flow rate. In step 301, the first estimator (3) receives data of the inlet temperature and pressure by the TMAP sensor (14), the EGR temperature from the EGR temperature sensor (13), air flow mass from the MAF sensor (12) and engine speed from the engine speed sensor (15). In step 302, the first estimator (3), based on the data received from each of the engine operation parameter sensors, determines at least one of the inlet pressure or the exhaust pressure of the charge to be inlet into the at least one cylinder (8). The first estimator (3) determines the inlet pressure of the charge, using mass, energy balance and ideal gas equation mentioned below. ……………… (Eq.6) On substituting corresponding values in the equation (Eq. 6), the inlet pressure is determined. In an embodiment, the exhaust pressure may be computed by substituting exhaust parameters such as, but not limiting to, exhaust temperature, mass flow rate of exhaust and the like in (Eq. 6). In step 303, the first estimator (3) procures the engine volumetric efficiency data from a look-up table [i.e. prefeed data of optimal working conditions for efficient working of the engine (1)] stored in the memory unit corresponding to the plurality of operating parameters of the engine (1). In an embodiment, the plurality of operating parameters may be engine speed, vehicle speed, engine operating temperature and the like. In step 304, the first estimator (3) retrieves a corresponding engine volumetric efficiency computed by the second estimator (4). In this step, the retrieved data of the engine volumetric efficiency value is compared with the computed volumetric efficiency value to determine an equivalent engine volumetric efficiency. Upon substitution of corresponding values from each of the engine operation parameter sensors, the equivalent engine volumetric efficiency is determined. In step 305, the first estimator (3) determines the EGR flow rate, based on the computed engine volumetric efficiency and the intake temperature or the exhaust temperature by following equation Eq. 7. ………… (Eq. 7) In an embodiment, by using the sliding mode estimator, the following may also be used for computing EGR flow rate. …… (Eq. 8) Figure 4 in one exemplary embodiment of the present disclosure, illustrates process flow chart of the second estimator (4), for estimating cylinder mass flow rate. In step 401, the second estimator (4) receives data of the inlet temperature and pressure by the TMAP sensor (14), the EGR temperature from the EGR temperature sensor (13), air flow mass from the MAF sensor (12) and engine speed from the engine speed sensor (15). In step 402, the second estimator (4) computes intake temperature or exhaust temperature of the charge, based on the plurality of operating parameters of the engine (1). The second estimator (4) computes the intake temperature or exhaust temperature of the pressure, using the mass, energy balance and ideal gas equation mentioned below. …………. (Eq. 9) In an embodiment, the exhaust temperature may be computed by substituting exhaust parameters such as, but not limiting to, exhaust pressure, mass flow rate of exhaust and the like in Eq. 9. In step 403, the second estimator (4) procures the engine volumetric efficiency data from the look-up table [i.e. prefeed data of optimal working conditions for efficient working of the engine] stored in the memory unit corresponding to the plurality of operating parameters of the engine (1). In an embodiment, the plurality of operating parameters may be engine speed, vehicle speed, engine operating temperature and the like. In step 404, the second estimator (4) retrieves the EGR flow rate computed by the first estimator (3). In step 405, the second estimator (4) computes the engine volumetric efficiency based on the plurality of operating parameters and the EGR flow rate. Simultaneously, the EGR flow rate is also calculated corresponding to the engine volumetric efficiency. This configuration, corrects the data and thereby eliminates error readings in the data. The equivalent engine volumetric efficiency value is determined based on the computed intake pressure by use of following equations. ……………….. (Eq. 10) ……… (Eq. 11) In an exemplary embodiment, the Eqs. 9 and 10 may be further discretized as ..(Eq. 12) ……. (Eq. 13) In an exemplary embodiment, the engine volumetric efficiency may also be computed by utilising the sliding mode estimators, which is governed by following equation Eq. 14. …… (Eq. 14) In step 406, the second estimator (4), based on the computed engine volumetric efficiency of engine (1) and the data received from first estimator (3) and the engine operation parameter sensors, determines the cylinder mass flow rate. The cylinder mass flow rate is determined, based on the following equation Eq. 15: ……… (Eq. 15) In an exemplary embodiment, the cylinder mass flow rate may also be computed by using sliding mode estimation, based on the following equation Eq. 16: …………. (Eq. 16) In an exemplary embodiment, the EGR flow rate estimation and the cylinder mass flow rate estimation may be estimated by computation methods such as, but not limiting to, finite difference method and the like. While using the estimation methods other than sliding mode estimation, filters such as, but not limiting to, low-pass filter, Kalman filter and the like may be used to filter the noise data in the estimation. The cylinder mass flow rate obtained from Eq. 16 is the corrected cylinder mass flow rate, which is corresponding to all the plurality of operating parameters of the engine (1). In this condition, the control unit (2) operates the EGR valve (5) and the second throttle valve (7b) corresponding to the data determined by the first estimator (3) and the second estimator (4). This operation ensures optimum combustion in the at least one cylinder (8). Thus, the control unit (2) controls the inlet flow parameters of the engine (1), thereby improving the efficiency and performance of the engine (1). Referring to figure 5, operational parameters of the engine generates noise data within the generated data. The noise data (17) generated by using the sliding mode estimation is reduced in comparison with the noise data (16) derived or computed using conventional methods. In an embodiment, the noise data may be reduced by utilizing the sliding mode estimation as described above, due to consideration of both pressure dynamics and temperature dynamics of operation parameters of the engine (1). Figures 6 and 7 are exemplary embodiments of the present disclosure, illustrating graphical representation of performance control over the engine (1). As illustrated in line 1 of figure 6, for a given accelerator pedal position and engine speed, data pertaining to a corresponding torque value is stored in the memory unit. Line 1, therefore corresponds to optimum conditions of torque that must be delivered from the engine (1), for a given accelerator pedal position. Line 2, is a torque curve obtained by computation of parameters using conventional methods. As illustrated in the Figure 6, line 2 includes a large deviation (A) of torque from the optimum value, as the time duration increases. Thus, line 2 may present abrupt engine operating conditions, which is undesirable. Line 3 is a torque curve, obtained by computation of parameters by method disclosed in the present disclosure. It is evident from line 3, in figure 6 that, employing the present method, for controlling the engine (1), considerably overlaps with the line 1, i.e. optimum conditions. Also, line 3 is in between line 1 and line 2, which inherently corresponds to a near optimum condition of the engine (1). Referring to figure 7, which illustrates an EGR flow rate vs time graph, for a given accelerator pedal position and engine speed. The EGR flow rate data is a corresponding data retrieved from the torque curve. Line 4 is the optimum EGR flow rate for a given accelerator pedal depression. Line 4, therefore corresponds to optimum conditions of the EGR flow rate that must be maintained for optimum performance of the engine (1). Line 5, is an EGR flow rate curve obtained by computation of the EGR flow rate by conventional methods. It is evident that line 5, clearly overshoots from the optimum conditions i.e. line 4. The overshoot in EGR value may considerably vary the performance of the engine (1). Line 6, is an EGR flow rate curve obtained by computation of EGR flow rate by the present method. It is evident that line 6, is considerably overlapping with the line 4 of the graph. Thus, for a given accelerator pedal depression, a near optimum EGR flow rate can be obtained by the present method. Thereby, obtain a near optimum control of the engine (1), inherently improving engine performance. Advantages The present disclosure provides a cost-effective method for estimating the inlet flow parameters of the engine, by eliminating dependency of differential pressure sensor in the system. The present disclosure provides a method for controlling inlet flow parameters of the engine, which improves engine efficiency and performance in all operating conditions. Equivalents: With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity. It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should typically be interpreted to mean "at least one" or "one or more"); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to "at least one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances, where a convention analogous to "at least one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B." While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims. REFERRAL NUMERALS REFERRAL NUMERALS DESCRIPTION 100 System for controlling fluid flow parameters 1 Engine 2 Control unit 3 First estimator 4 Second estimator 5 EGR valve 6 Intake manifold 7 Throttle body 7a First throttle valve 7b Second throttle valve 8 Cylinder of the engine 9 Compressor 10 Turbocharger 11 Catalytic convertor 12 MAF sensor 13 EGR temperature sensor 14 TMAP sensor 15 Engine speed sensor 16 Noise signal generated by conventional methods 17 Noise signal generated by sliding mode method 18 Turbine 19 Exhaust manifold 20 EGR cooler 21 Intercooler 22 Air filter Tegr, EGR temperature Cylinder mass flow rate Engine Volumetric efficiency EGR flow rate Engine speed Effective engine volumetric efficiency MAF Mass air flow TMAP Temperature and pressure of charge

Claims:1. A method for controlling fluid flow parameters for an engine (1), comprising:
computing, by a first estimator (3) associated to a control unit (2), at least one of an intake pressure or an exhaust pressure of the engine (1);
computing, by a second estimator (4) associated with the control unit (2), at least one of an intake temperature or an exhaust temperature of the engine (1), wherein the second estimator (4) determines engine volumetric efficiency based on the at least one of the intake temperature or the exhaust temperature of the engine (1);
determining, by the first estimator (3), an Exhaust Gas Re-circulation (EGR) flow rate for the engine (1) based on the computed engine volumetric efficiency and the at least one of the intake pressure or the exhaust pressure;
determining, by the second estimator (4), a cylinder mass flow rate based on the computed Exhaust Gas Re-circulation (EGR) flow rate and the at least one of the intake temperature and the exhaust temperature;
operating, by the control unit (2), an Exhaust Gas Re-circulation (EGR) valve (5) in fluid communication with an intake manifold (6) of the engine (1) to allow Exhaust Gas Re-circulation (EGR) flow corresponding to the Exhaust Gas Re-circulation (EGR) flow rate into the intake manifold (6); and
operating, by the control unit (2), a throttle body (7) in fluid communication with the intake manifold (6), to allow air flow into the engine (1) corresponding to the cylinder mass flow rate, thereby controlling the inlet flow parameters of the engine (1).

2. The method as claimed in claim 1, comprises receiving, by the control unit (2), a plurality of operating parameters of the engine (1).

3. The method as claimed in claim 2, wherein the plurality of operating parameters of the engine (1) include:
a mass air flow into the engine (1), measured by a mass air flow (MAF) sensor (12);
temperature of exhaust gas, measured by an EGR temperature sensor (13);
engine speed, measured by an engine speed sensor (15);
intake manifold pressure, measured by a temperature manifold absolute pressure (TMAP) sensor (14);
engine volumetric efficiency retrieved from a memory unit associated to the control unit (2),
wherein the mass air flow (MAF) sensor (12), the temperature sensor, the speed sensor and the temperature manifold absolute pressure (TMAP) sensor are communicatively connected to the control unit (2).

4. A system (100) for controlling inlet flow parameters of an engine (1), the system (100) comprising:
a first estimator (3) associated with a control unit (2) and configured to:
compute, at least one of an intake pressure or an exhaust pressure of the engine (1), based on the plurality of operating parameters;
determine Exhaust Gas Re-circulation (EGR) flow rate based on the engine volumetric efficiency computed by a second estimator (4) and the at least one of intake pressure or the exhaust pressure;
the second estimator (4) associated with the control unit (2) and configured to:
compute, at least one of an intake temperature or an exhaust temperature of the engine (1);
determine, engine volumetric efficiency based on the at least one of intake temperature or the exhaust temperature;
determine, a cylinder mass flow rate based on the computed Exhaust Gas Re-circulation (EGR) flow rate and the at least one of intake temperature or the exhaust temperature;
wherein, the control unit (2)
operates an Exhaust Gas Re-circulation (EGR) valve (5) in fluid communication with an intake manifold (6) of the engine (1) to allow Exhaust Gas Re-circulation (EGR) flow into the intake manifold (6) corresponding to the Exhaust Gas Re-circulation (EGR) flow rate, and
operates a throttle body (7) in fluid communication with the intake manifold (6), to allow charge flow into the engine (1) corresponding to the cylinder mass flow rate, thereby controlling the fluid flow parameters of the engine (1).

5. The system (100) as claimed in claim 4, wherein the control unit (2) is configured to receive a plurality of operating parameters of the engine (1).

6. The system (100) as claimed in claim 4, comprises a mass air flow (MAF) sensor (12) positioned upstream of the throttle body (7), to measure mass air flow into the engine (1).

7. The system (100) as claimed in claim 4, comprises an EGR temperature sensor (13) positioned upstream of the Exhaust gas Re-circulation (EGR) valve (5), to measure temperature of exhaust gas.

8. The system (100) as claimed in claim 4, comprises an engine speed sensor (15) positioned in the engine (1), to measure engine speed.

9. The system (100) as claimed in claim 4, comprises a temperature manifold absolute pressure (T-MAP) sensor (14) positioned in the intake manifold (6), to measure intake manifold pressure.

10. The system (100) as claimed in claim 4, comprises a memory unit associated to the control unit (2), configured to store the plurality of operating parameters of the engine (1).

11. The system (100) as claimed in claim 4, wherein the mass air flow (MAF) sensor (12), the EGR temperature sensor (13), the engine speed sensor (15) and the temperature manifold absolute pressure (TMAP) sensor (14) are communicatively connected to the control unit (2).

12. A vehicle comprising a method for controlling fluid flow parameters for an engine (1) as claimed in claim 1.

13. A vehicle comprising a system (100) for controlling fluid flow parameters for an engine (1) as claimed in claim 4. , Description:TECHNICAL FIELD

Present disclosure relates to a vehicle. Particularly, embodiments of the disclosure relate to air-fuel ratio control systems for the vehicle. Embodiments of the disclosure further relate to a method for controlling fluid flow parameters for an engine of the vehicle.

BACKGROUND OF THE DISCLOSURE

Conventional internal combustion engines [IC Engines], operate by drawing in air-fuel mixture into its cylinders. The air-fuel mixture combusted in the IC engine is used to drive the crankshaft and generate power. The combusted air-fuel mixture residues exhaust gases and are exhausted out from the IC engine to atmosphere. The exhaust gases from the IC engine contains toxic substances such as carbon dioxide, carbon monoxide, Mono-Nitrogen oxides (NOx) and the like, which pollute the atmosphere. Therefore, according to the environmental norms, stringent emission regulations are enforced to vehicle manufacturers to restrict the amount of toxic exhaust gases released into the atmosphere or the environment from the IC engines. However, at the same time, consumers are also demanding engines with higher efficiency, without compromise in its performance. Hence, two-predominant requirements that vehicle manufacturers need to satisfy are, emission control norms and efficient IC Engines.

Advent of modern technology, has produced advanced combustion strategies or techniques to the existing design of IC engines. The combustion strategies or techniques control the amount of fuel or air mixture to be inlet into the engine, based on operating conditions of the engine. One such strategy or technique of combustion is Exhaust Gas-Recirculation [EGR]. In EGR, a portion of the exhaust gas is recirculated back into the engine. The recirculated exhaust gas may contain traces of unburnt fuel and therefore, this configuration reduces the amount of fuel drawn into the engine. Consequently, improving efficiency of the engine and satisfying the emission regulations.

To implement, EGR configuration in the engines, several control techniques, known as EGR estimation methods are devised. The control techniques are configured to estimate the amount of exhaust gas that must be inlet into the engine for optimum combustion, based on several parameters such as power demand, operating temperature and the like. To determine operating parameters of the engine, several sensors are configured at predetermined locations. These sensors provide data to a control unit in real-time for estimation of exhaust gas flow rate into the engine. However, this involves use of various sensors, particularly a differential pressure sensor for providing feedback to the control unit. The differential pressure sensor is provided to monitor the exhaust gas pressure of the engine. At pressure conditions below a predetermined limit, the differential pressure sensor, is incapable of detecting pressure of the exhaust gas. Thus, at exhaust gas pressure below a predetermined limit, the value received by the control unit from the differential pressure sensor is erroneous or inaccurate. This inherently results in incorrect estimation of fuel or air mixture into the engine, leading to improper combustion, inefficiency and abrupt combustion of fuel within the IC engine.

To overcome the aforesaid problem, additional sensors may be provided for accurate detection of pressure, even at lower pressure conditions. However, use of additional sensors significantly makes the system costly, complex and cumbersome.

The present disclosure is directed to overcome one or more limitations stated above.

The information disclosed in this background of the disclosure section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art

SUMMARY OF THE DISCLOSURE

One or more shortcomings of conventional assemblies are overcome and additional advantages are provided through the provision of an assembly as claimed in the present disclosure. Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.

In one non-limiting embodiment of the present disclosure, a method for controlling fluid flow parameters for an engine is disclosed. The method comprising computing by a first estimator associated to a control unit, at least one of an intake pressure or an exhaust pressure of the engine. A second estimator associated with the control unit, computes at least one of an intake temperature or an exhaust temperature of the engine. The second estimator determines engine volumetric efficiency based on the at least one of an intake temperature or an exhaust temperature of the engine. The first estimator determines an Exhaust Gas Re-circulation (EGR) flow rate for the engine based on the computed engine volumetric efficiency and the at least one of the intake pressure or the exhaust pressure. The second estimator determines a cylinder mass flow rate based on the computed Exhaust Gas Re-circulation (EGR) flow rate and the at least one of intake temperature and the exhaust temperature. The control unit, operates an Exhaust Gas Re-circulation (EGR) valve in fluid communication with an intake manifold of the engine to allow Exhaust Gas Re-circulation (EGR) flow at the determined rate into the intake manifold. The control unit operates a throttle body in fluid communication with the intake manifold, to allow air flow into the engine, based on the computed cylinder mass flow rate, thereby controlling the inlet flow parameters of the engine.

In an embodiment, the control unit receives a plurality of operating parameters of the engine.

In an embodiment, the plurality of operating parameters of the engine include a mass air flow through the engine, measured by a mass air flow (MAF) sensor. Also, temperature of exhaust gas, measured by a temperature sensor and engine speed, measured by a speed sensor. Additionally, intake manifold pressure, is measured by a temperature manifold absolute pressure (T-MAP) sensor and engine volumetric efficiency retrieved from a memory unit associated to the control unit. The mass air flow (MAF) sensor, temperature sensor, speed sensor and temperature manifold absolute pressure (T-MAP) sensor are associated to the control unit.

In an embodiment, a system for controlling inlet flow parameters for an engine is disclosed. The system comprising a first estimator associated with a control unit. The first estimator is configured to compute, at least one of an intake pressure or an exhaust pressure of the engine, based on the plurality of operating parameters. The first estimator further determines Exhaust Gas Re-circulation (EGR) flow rate based on the engine volumetric efficiency computed by a second estimator and the intake pressure estimate. The second estimator is associated with the control unit and is configured to compute, at least one of an intake temperature estimate of the engine, compute engine efficiency based on the intake temperature or an exhaust temperature. Lastly, to determine a cylinder mass flow rate based on the computed Exhaust Gas Re-circulation (EGR) flow rate and the at least one of the intake temperature and the exhaust temperature. The control unit operates an Exhaust Gas Re-circulation (EGR) valve in fluid communication with an intake manifold of the engine to allow computed Exhaust Gas Re-circulation (EGR) flow into the intake manifold, and operates a throttle body in fluid communication with the intake manifold, to allow charge flow into the engine based on the computed cylinder mass flow rate, thereby controlling the fluid flow parameters of the engine.

In an embodiment, a mass air flow (MAF) sensor is positioned upstream of the throttle body, to measure mass air flow into the engine.

In an embodiment, a temperature sensor is positioned upstream of the Exhaust gas Re-circulation (EGR) valve to measure temperature of exhaust gas.

In an embodiment, a speed sensor is positioned in the engine to measure engine speed.

In an embodiment, a temperature manifold absolute pressure (T-MAP) sensor is positioned in the intake manifold, to measure intake manifold pressure.

In an embodiment, a memory unit associated to the control unit is provided and configured to store plurality of operating parameters of the engine.

In an embodiment, the mass air flow (MAF) sensor, temperature sensor, speed sensor and temperature manifold absolute pressure (T-MAP) sensor are communicatively connected to the control unit.

It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined together to form a further embodiment of the disclosure.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF DRAWINGS

The novel features and characteristic of the disclosure are set forth in the appended claims. The disclosure itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings. One or more embodiments are now described, by way of example only, with reference to the accompanying drawings wherein like reference numerals represent like elements and in which:

Figure 1 illustrates a block diagram of a system for controlling fluid flow parameters for an engine, in accordance with an exemplary embodiment of the present disclosure.

Figure 2 illustrates a block diagram of a first estimator and a second estimator configured in the system of Figure 1, in accordance with an exemplary embodiment of the present disclosure.

Figure 3 illustrates process flow chart of the first estimator, in accordance with an embodiment of the present disclosure.

Figure 4 illustrates process flow chart of the second estimator, in accordance with an embodiment of the present disclosure.

Figures 5 illustrates graphical representation of a signal generated by the first estimator and the second estimator, in accordance with an embodiment of the present disclosure.

Figure 6 illustrates graphical representation of a torque curve, in accordance with an embodiment of the present disclosure.

Figure 7 illustrates graphical representation of an EGR flow rate curve, in accordance with an embodiment of the present disclosure.

The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily 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.

DETAILED DESCRIPTION

While the embodiments in the disclosure are subject to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the figures and will be described below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the scope of the disclosure.

It is to be noted that a person skilled in the art would be motivated from the present disclosure a method for controlling fluid flow parameters of an engine, which may vary based on configuration of the engine. However, such modifications should be construed within the scope of the disclosure. Accordingly, the drawings show only those specific details that are pertinent to understand the embodiments of the present disclosure, so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein.

The terms “comprises”, “comprising”, or any other variations thereof used in the disclosure, are intended to cover a non-exclusive inclusion, such that a device, system, assembly that comprises a list of components does not include only those components but may include other components not expressly listed or inherent to such system, or assembly, or device. In other words, one or more elements in a system or device proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or device.

Embodiments of the disclosure discloses, a method for controlling fluid flow parameters for an engine. The method includes computing an intake pressure of the engine by a first estimator and an intake temperature of the engine by a second estimator, wherein the first estimator and the second estimator are associated with the control unit. The second estimator determines engine volumetric efficiency, based on the determined intake temperature. The first estimator determines an Exhaust Gas Re-circulation (EGR) flow rate for the engine, based on the computed engine volumetric efficiency and the intake pressure estimate. The second estimator determines a cylinder mass flow rate based on the computed Exhaust Gas Re-circulation (EGR) flow rate and the intake temperature estimate. The control unit operates an Exhaust Gas Re-circulation (EGR) valve in fluid communication with an intake manifold of the engine, to allow Exhaust Gas Re-circulation (EGR) flow at a determined rate into the intake manifold. The control unit operates a throttle body in fluid communication with the intake manifold, to allow air flow into the engine based on the computed cylinder mass flow rate, thereby controlling the inlet flow parameters of the engine.

The present disclosure further provides a system for controlling fluid flow parameters of the engine. The system includes the first estimator and the second estimator, associated with the control unit. The first estimator is configured to compute, an intake pressure estimate of the engine, based on the plurality of operating parameters. The first estimator, determines Exhaust Gas Re-circulation (EGR) flow rate based on the engine volumetric efficiency computed by the second estimator and the intake pressure estimate. The second estimator is associated with the control unit and is configured to compute, an intake temperature estimate of the engine, engine volumetric efficiency based on the intake temperature estimate and determine, a cylinder mass flow rate based on the computed Exhaust Gas Re-circulation (EGR) flow rate and the intake temperature estimate. The control unit operates an Exhaust Gas Re-circulation (EGR) valve in fluid communication with an intake manifold of the engine to allow computed Exhaust Gas Re-circulation (EGR) flow into the intake manifold. The control unit, operates a throttle body in fluid communication with the intake manifold, to allow charge flow into the engine based on the computed cylinder mass flow rate, thereby controlling the fluid flow parameters of the engine.

The following paragraphs describe the present disclosure with reference to Figures 1 to 7. In the Figures, the same element or elements which have similar functions are indicated by the same reference signs.

Figure 1 is an exemplary embodiment of the present disclosure, which illustrates a system (100) for controlling fluid flow parameters for an engine (1). The system (100) includes a control unit (2) configured to control operations of the engine (1).

The engine (1) includes at least one cylinder (8) in fluid communication with a throttle body (7) and an intake manifold (6) for receiving air-fuel mixture. The throttle body (7) may include a first throttle valve (7a) and a second throttle valve (7b). A Mass-Air Flow (MAF) sensor (12) is provided upstream of the first throttle valve (7a), for measuring the amount of air flowing from the first throttle valve (7a) via an air filter (22). The metered air is inlet into a compressor (9) of a turbocharger (10) of the engine (1), for pressurising the air. The engine (1) as illustrated in figure 1 includes an Exhaust Gas Re-circulation (EGR) system (200) connected to an exhaust manifold (19) via a catalytic converter (11) of the engine (1), for routing exhaust gas. The exhaust gas is routed to a turbine (18), for operating the compressor (9) before releasing the exhaust gas to atmosphere. The EGR system (200) includes an EGR valve (5) and an EGR cooler (20) in fluid communication with the compressor (9), for routing part of the exhaust gas into the compressor (9). An EGR temperature sensor (13) is configured upstream of the EGR valve (5) to measure temperature of the exhaust gas routed from the engine (1). The compressor (9) is further configured to pressurise air and exhaust gas mixture from the EGR valve (5), before inletting into an intake manifold (6) via an intercooler (21). The intake manifold (6) includes a Temperature Manifold Absolute Pressure (TMAP) sensor (14), for measuring the temperature and pressure of air-fuel mixture [hereinafter referred to as charge] is inlet into the engine (1). The intake manifold (6) is in fluid communication with the second throttle valve (7b), for controlling the charge flow into the engine (1). The engine (1) also includes an engine speed sensor (15) for measuring the speed of rotation of a crankshaft in the engine (1).

The control unit (2) is interfaced to each of the TMAP sensor (14), the MAF sensor (12), the EGR temperature sensor (13), the engine speed sensor (15), the first throttle body (7a) and the second throttle body (7b) for controlling operation of the engine (1). The control unit (2) also includes a memory unit, for storing data pertaining to an engine volumetric efficiency. In an embodiment, the memory unit is selected from group such as but not limiting to RAM, ROM …etc. which serves the purpose of storing data.

Referring to figure 2, a first estimator (3) and a second estimator (4) are associated with the control unit (2). In an embodiment, the first estimator (3) and the second estimator (4) are configured in the control unit (2). The first estimator (3) and the second estimator (4) may be configured to receive input data from each of the TMAP sensor (14), the MAF sensor (12), the EGR temperature sensor (13) and the engine speed sensor (15) [hereinafter referred to as engine operation parameter sensors]. The first estimator (3) may be configured to compute at least one of inlet pressure of the charge or an exhaust pressure of the engine (1), based on the data received from each of the sensors. The first estimator (3) may be configured to determine, Exhaust Gas Re-circulation (EGR) flow rate into the at least one cylinder (8), based on the data received by the first estimator (3) and the computed inlet pressure or the exhaust pressure.

The second estimator (4) is interfaced to the first estimator (3) and is configured to compute at least one of inlet temperature or an exhaust temperature of the engine (1), based on the data received from each of the engine operation parameter sensors. The second estimator (4) determines, engine volumetric efficiency based on the data received by the first estimator (3) and the computed inlet temperature or the exhaust temperature of the engine (1). The data computed by the first estimator (3) and the second estimator (4) are collated to determine a cylinder mass flow rate. In an embodiment, the cylinder mass flow rate may be the amount of the charge that is inlet into the at least one cylinder (8), based on the operating parameters.

In an embodiment, the engine volumetric efficiency may be procured from a calibrated engine dynamometer, while operating the engine (1) at predetermined conditions including, but not limited to, power demand, air-fuel ratio, inlet temperature and pressure, outlet pressure and temperature and the like. In an embodiment, the control unit (2) may be configured to store in the memory unit, data received from the sensors interfaced to the engine (1).

In an embodiment, the first estimator (3) may be a sliding mode estimator. In another embodiment, the first estimator (3) may be a processing unit, associated to the control unit (2) for computing the EGR flow rate for the engine (1).

In an embodiment, the second estimator (4) may be a sliding mode estimator. In another embodiment, the second estimator (4) may be a processing unit, configured for computing the cylinder mass flow rate for the engine (1).

In an exemplary embodiment, the sliding mode estimator of the first estimator (3) and the second estimator (4) operates based on a discrete time equation, which is arrived at as follows:

…………………………………… (Eq. 1)

The sliding surface are chosen as
………………….. (Eq. 2) and
……………… (Eq. 3)

The inputs for Eq. 2 and Eq. 3 are

………………….. (Eq. 4)
…………………………. (Eq. 5)

Wherein, is the derivative of Eq. 4 by Euler’s differentiation method. In an exemplary embodiment, value of ?=1.5 and ?=1.1 may be tuned further is the suprimal value of second derivative of the signal. In another embodiment, the value may also be a large value [1e5] and may be later reduced to a reasonable value by tuning.

From sliding mode estimator, the value of inlet pressure and inlet temperature can be obtained. This is done by using equations Eqs. 1-5, and substituting F(k) with and separately. Thus, there are two estimations one for pressure parameter [or pressure dynamics] and other for temperature parameter [or temperature dynamics]. In an embodiment, there are two sliding model algorithms operating simultaneously for determining EGR flow rate and cylinder mass flow rate.

Figure 3, in one exemplary embodiment of the present disclosure, illustrates a process flowchart of the first estimator (3), for estimating the EGR flow rate.

In step 301, the first estimator (3) receives data of the inlet temperature and pressure by the TMAP sensor (14), the EGR temperature from the EGR temperature sensor (13), air flow mass from the MAF sensor (12) and engine speed from the engine speed sensor (15).

In step 302, the first estimator (3), based on the data received from each of the engine operation parameter sensors, determines at least one of the inlet pressure or the exhaust pressure of the charge to be inlet into the at least one cylinder (8). The first estimator (3) determines the inlet pressure of the charge, using mass, energy balance and ideal gas equation mentioned below.
……………… (Eq.6)

On substituting corresponding values in the equation (Eq. 6), the inlet pressure is determined. In an embodiment, the exhaust pressure may be computed by substituting exhaust parameters such as, but not limiting to, exhaust temperature, mass flow rate of exhaust and the like in (Eq. 6).

In step 303, the first estimator (3) procures the engine volumetric efficiency data from a look-up table [i.e. prefeed data of optimal working conditions for efficient working of the engine (1)] stored in the memory unit corresponding to the plurality of operating parameters of the engine (1). In an embodiment, the plurality of operating parameters may be engine speed, vehicle speed, engine operating temperature and the like.

In step 304, the first estimator (3) retrieves a corresponding engine volumetric efficiency computed by the second estimator (4). In this step, the retrieved data of the engine volumetric efficiency value is compared with the computed volumetric efficiency value to determine an equivalent engine volumetric efficiency.

Upon substitution of corresponding values from each of the engine operation parameter sensors, the equivalent engine volumetric efficiency is determined.

In step 305, the first estimator (3) determines the EGR flow rate, based on the computed engine volumetric efficiency and the intake temperature or the exhaust temperature by following equation Eq. 7.

………… (Eq. 7)

In an embodiment, by using the sliding mode estimator, the following may also be used for computing EGR flow rate.

…… (Eq. 8)

Figure 4 in one exemplary embodiment of the present disclosure, illustrates process flow chart of the second estimator (4), for estimating cylinder mass flow rate.

In step 401, the second estimator (4) receives data of the inlet temperature and pressure by the TMAP sensor (14), the EGR temperature from the EGR temperature sensor (13), air flow mass from the MAF sensor (12) and engine speed from the engine speed sensor (15).

In step 402, the second estimator (4) computes intake temperature or exhaust temperature of the charge, based on the plurality of operating parameters of the engine (1). The second estimator (4) computes the intake temperature or exhaust temperature of the pressure, using the mass, energy balance and ideal gas equation mentioned below.

…………. (Eq. 9)

In an embodiment, the exhaust temperature may be computed by substituting exhaust parameters such as, but not limiting to, exhaust pressure, mass flow rate of exhaust and the like in Eq. 9.

In step 403, the second estimator (4) procures the engine volumetric efficiency data from the look-up table [i.e. prefeed data of optimal working conditions for efficient working of the engine] stored in the memory unit corresponding to the plurality of operating parameters of the engine (1). In an embodiment, the plurality of operating parameters may be engine speed, vehicle speed, engine operating temperature and the like.

In step 404, the second estimator (4) retrieves the EGR flow rate computed by the first estimator (3).

In step 405, the second estimator (4) computes the engine volumetric efficiency based on the plurality of operating parameters and the EGR flow rate. Simultaneously, the EGR flow rate is also calculated corresponding to the engine volumetric efficiency. This configuration, corrects the data and thereby eliminates error readings in the data. The equivalent engine volumetric efficiency value is determined based on the computed intake pressure by use of following equations.

……………….. (Eq. 10)

……… (Eq. 11)

In an exemplary embodiment, the Eqs. 9 and 10 may be further discretized as

..(Eq. 12)

……. (Eq. 13)

In an exemplary embodiment, the engine volumetric efficiency may also be computed by utilising the sliding mode estimators, which is governed by following equation Eq. 14.

…… (Eq. 14)

In step 406, the second estimator (4), based on the computed engine volumetric efficiency of engine (1) and the data received from first estimator (3) and the engine operation parameter sensors, determines the cylinder mass flow rate. The cylinder mass flow rate is determined, based on the following equation Eq. 15:

……… (Eq. 15)

In an exemplary embodiment, the cylinder mass flow rate may also be computed by using sliding mode estimation, based on the following equation Eq. 16:

…………. (Eq. 16)

In an exemplary embodiment, the EGR flow rate estimation and the cylinder mass flow rate estimation may be estimated by computation methods such as, but not limiting to, finite difference method and the like. While using the estimation methods other than sliding mode estimation, filters such as, but not limiting to, low-pass filter, Kalman filter and the like may be used to filter the noise data in the estimation.

The cylinder mass flow rate obtained from Eq. 16 is the corrected cylinder mass flow rate, which is corresponding to all the plurality of operating parameters of the engine (1). In this condition, the control unit (2) operates the EGR valve (5) and the second throttle valve (7b) corresponding to the data determined by the first estimator (3) and the second estimator (4). This operation ensures optimum combustion in the at least one cylinder (8). Thus, the control unit (2) controls the inlet flow parameters of the engine (1), thereby improving the efficiency and performance of the engine (1).

Referring to figure 5, operational parameters of the engine generates noise data within the generated data. The noise data (17) generated by using the sliding mode estimation is reduced in comparison with the noise data (16) derived or computed using conventional methods. In an embodiment, the noise data may be reduced by utilizing the sliding mode estimation as described above, due to consideration of both pressure dynamics and temperature dynamics of operation parameters of the engine (1).

Figures 6 and 7 are exemplary embodiments of the present disclosure, illustrating graphical representation of performance control over the engine (1).

As illustrated in line 1 of figure 6, for a given accelerator pedal position and engine speed, data pertaining to a corresponding torque value is stored in the memory unit. Line 1, therefore corresponds to optimum conditions of torque that must be delivered from the engine (1), for a given accelerator pedal position. Line 2, is a torque curve obtained by computation of parameters using conventional methods. As illustrated in the Figure 6, line 2 includes a large deviation (A) of torque from the optimum value, as the time duration increases. Thus, line 2 may present abrupt engine operating conditions, which is undesirable. Line 3 is a torque curve, obtained by computation of parameters by method disclosed in the present disclosure. It is evident from line 3, in figure 6 that, employing the present method, for controlling the engine (1), considerably overlaps with the line 1, i.e. optimum conditions. Also, line 3 is in between line 1 and line 2, which inherently corresponds to a near optimum condition of the engine (1).

Referring to figure 7, which illustrates an EGR flow rate vs time graph, for a given accelerator pedal position and engine speed. The EGR flow rate data is a corresponding data retrieved from the torque curve. Line 4 is the optimum EGR flow rate for a given accelerator pedal depression. Line 4, therefore corresponds to optimum conditions of the EGR flow rate that must be maintained for optimum performance of the engine (1). Line 5, is an EGR flow rate curve obtained by computation of the EGR flow rate by conventional methods. It is evident that line 5, clearly overshoots from the optimum conditions i.e. line 4. The overshoot in EGR value may considerably vary the performance of the engine (1). Line 6, is an EGR flow rate curve obtained by computation of EGR flow rate by the present method. It is evident that line 6, is considerably overlapping with the line 4 of the graph. Thus, for a given accelerator pedal depression, a near optimum EGR flow rate can be obtained by the present method. Thereby, obtain a near optimum control of the engine (1), inherently improving engine performance.

Advantages
The present disclosure provides a cost-effective method for estimating the inlet flow parameters of the engine, by eliminating dependency of differential pressure sensor in the system.

The present disclosure provides a method for controlling inlet flow parameters of the engine, which improves engine efficiency and performance in all operating conditions.

Equivalents:
With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should typically be interpreted to mean "at least one" or "one or more"); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to "at least one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances, where a convention analogous to "at least one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B."

While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

REFERRAL NUMERALS
REFERRAL NUMERALS DESCRIPTION
100 System for controlling fluid flow parameters
1 Engine
2 Control unit
3 First estimator
4 Second estimator
5 EGR valve
6 Intake manifold
7 Throttle body
7a First throttle valve
7b Second throttle valve
8 Cylinder of the engine
9 Compressor
10 Turbocharger
11 Catalytic convertor
12 MAF sensor
13 EGR temperature sensor
14 TMAP sensor
15 Engine speed sensor
16 Noise signal generated by conventional methods
17 Noise signal generated by sliding mode method
18 Turbine
19 Exhaust manifold
20 EGR cooler
21 Intercooler
22 Air filter
Tegr, EGR temperature

Cylinder mass flow rate

Engine Volumetric efficiency

EGR flow rate

Engine speed

Effective engine volumetric efficiency
MAF Mass air flow
TMAP Temperature and pressure of charge