Description:FIELD
The present disclosure generally relates to the field of automotive engines. Particularly, the present disclosure relates to a variable valve timing control system for the engine and a method thereof.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
As stringent regulations to reduce carbon emissions become more stringent, engine design must be optimized to be more efficient and provide better fuel economy. One such engine design optimization is to run the engine in the Miller combustion cycle rather than the standard Otto combustion cycle. When compared to traditional engines, the compression ratio maintained on Miller cycle engines is higher, while valve timing is designed to have the least amount of pumping loss. The disadvantage of running the engine on valve timing with minimal pumping loss is that it reduces the engine's ability to produce torque quickly, making engine response slower and causing turbo charger overload. However, if the engine is operated with the best valve timing for rapid torque generation, the engine is more prone to knock due to the higher compression ratio.
There is, therefore, felt a need to develop a variable valve timing control system for an engine and a method for the same, that alleviates the aforementioned disadvantages.
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 provide a variable valve timing control system for the engine.
Another object of the present disclosure is to provide a variable valve timing control system for the engine, which can adjust the engine valve based on engine knocking tendency.
Another object of the present disclosure is to provide a variable valve timing control system for the engine, which can generate separate valve timing for steady state and dynamic operation for different engine knocking tendencies.
Yet another object of the present disclosure is to provide a variable valve timing control system for the engine which can achieve maximum engine performance for a fuel with less knocking tendency.
Still another object of the present disclosure is to provide a variable valve timing control system for the engine which can achieve maximum engine protection for a fuel with more knocking tendency.
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 envisages a variable valve timing (VVT) control system for an engine. The engine has inlet valves and exhaust valves. The system comprises at least one sensor, a memory, and a control unit.
The sensor is coupled to an engine block of the engine. The sensor is configured to sense vibrations of the engine caused due to uneven combustion of fuel and to generate a sensed signal. The memory is configured to store a first VVT lookup-map corresponding to realize a fuel-efficiency and a second VVT lookup-map corresponding to realize a minimum knocking.
The control unit is communicatively coupled to the sensor, the memory, the inlet valves, and the exhaust valves. The control unit comprises a knocking detection module and a selection module. The knocking detection module is configured to receive the sensed signal from the sensor and to process the sensed signal to determine the severity of the knocking of the engine. The selection module is configured to select one of the first VVT lookup-map and the second VVT lookup-map based on the severity of the knocking of the engine, wherein the control unit is configured to control at least one of the inlet valves and the exhaust valves with valve timings of the selected VVT lookup-map.
In an embodiment, the control unit is configured to select the first VVT lookup-map when there is a low severity of the knocking of the engine. The control unit is configured to select the second VVT lookup-map when there is a high severity of the knocking of the engine.
In an embodiment, the control unit further comprises a weighing module and a VVT lookup-map generator. The weighing module is configured to determine a weightage factor for an intermediate severity of the knocking of the engine. The VVT lookup-map generator is configured to receive the weightage factor, the first VVT lookup-map, and the second VVT lookup-map and to generate a third VVT lookup-map accordingly. In an aspect, the control unit is configured to control at least one of the inlet valves and the exhaust valves with valve timings based on the generated third VVT lookup-map for the intermediate severity of the knocking of the engine.
In an embodiment, the VVT lookup-map generator comprises a multiplier module and a summing module, and the VVT lookup-map generator is configured to:
• multiply, by the multiplier module, the weightage factor with the first VVT lookup-map to obtain a weighted first VVT lookup-map;
• multiply, by the multiplier module, the weightage factor with the second VVT lookup-map to obtain a weighted second VVT lookup-map; and
• sum, by the summing module, the weighted first VVT lookup-map and the weighted second VVT lookup-map to obtain the third VVT lookup-map.
In an embodiment, the control unit is configured to control valve timing depending on operating conditions of the engine. In an aspect, the operating conditions of the engine include one of a steady state condition and/or a dynamic state condition.
In an embodiment, the first VVT lookup-map, second VVT lookup-map and the third VVT lookup-map include valve timings corresponding to each of an engine-speed and an engine-load.
The present disclosure further envisages, a variable valve timing (VVT) control method for an engine having inlet valves and exhaust valves, the method comprising:
• sensing, by at least one sensor, vibrations of the engine caused due to uneven combustion of fuel and to generate a sensed signal;
• storing, in a memory, a first VVT lookup-map corresponding to realize a fuel-efficiency and a second VVT lookup-map corresponding to realize a minimum knocking;
• receiving, by a knocking detection module of a control unit, the sensed signal from the sensor;
• processing, by the knocking detection module, the sensed signal to determine the severity of the knocking of the engine;
• selecting, by a selection module of the control unit, one of the first VVT lookup-map and the second VVT lookup-map based on the severity of the knocking of the engine; and
• controlling, by the control unit, at least one of the inlet valves and the exhaust valves with valve timings of the selected lookup-map.
In an embodiment, the method further comprises a method step of selecting the first VVT lookup-map when there is a low severity of the knocking of the engine. In an embodiment, the method further comprises a method step of selecting the second VVT lookup-map when there is a high severity of the knocking of the engine.
In an embodiment, the method further includes method steps of:
• determining, by a weighing module of the control unit, a weightage factor for an intermediate severity of the knocking of the engine; and
• receiving, by a VVT lookup-map generator of the control unit, to receive the weightage factor, the first VVT lookup-map and the second VVT lookup-map;
• generating, by the VVT lookup-map generator of the control unit, a third VVT lookup-map; and
• controlling, by the control unit, at least one of the inlet valves and the exhaust valves having valve timings based on the generated third VVT lookup-map for the intermediate severity of the knocking of the engine.
In an embodiment, the method further comprises a method step of generating the third VVT lookup-map includes the following steps:
• multiplying, by a multiplier module, the weightage factor with the first VVT lookup-map to obtain a weighted first VVT lookup-map;
• multiplying, by the multiplier module, the weightage factor with the second VVT lookup-map to obtain a weighted second VVT lookup-map; and
• summing, by a summing module, the weighted first VVT lookup-map and the weighted second VVT lookup-map to obtain the third VVT lookup-map.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
A variable valve timing control system for the engine and a method thereof of the present disclosure will now be described with the help of the accompanying drawing, in which:
Figure 1 illustrates a block diagram of a variable valve timing control system for the engine, in accordance with an embodiment of the present disclosure;
Figures 2 illustrates graphs relating valve timing adjustment based on knocking tendency and processed knock sensor signal, in accordance with an embodiment of the present disclosure;
Figure 3 illustrates a graph showing dynamic torque comparison with higher RON & lower RON fuel, in accordance with an embodiment of the present disclosure; and
Figure 4 illustrates a flow chart of a variable valve timing control method for the engine, in accordance with an embodiment of the present disclosure.
LIST OF REFERENCE NUMERALS USED IN THE DESCRIPTION AND DRAWING:
100 System
20 Sensor
30 Memory
40 Control unit
40a Knocking detection module
40b Selection module
40c Weighing module
40d VVT lookup-map generator
40d-1 Multiplier module
40d-2 Summing module
200 Method
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 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, 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.
When an element is referred to as being “mounted on”, “engaged to”, “connected to” or “coupled to” another element, it may be directly on, engaged, connected or coupled to the other element. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed elements.
The present disclosure envisages a variable valve timing VVT control system 100 for an engine having inlet valves and exhaust valves and is now described with reference to Figures 1 to 4.
As shown in Figure 1, the system 100 comprises at least one sensor 20, a memory 30, and a control unit 40.
The sensor 20 is mounted on an engine block of the engine. The sensor 20 is configured to sense vibrations of the engine caused due to uneven combustion of fuel and to generate a sensed signal. In an embodiment, the sensor 20 can be selected from a group consisting of an accelerometer, piezoelectric sensor, capacitive sensor, pressure sensor, vibration sensor and the like.
The memory 30 is configured to store a first VVT lookup-map corresponding to realize fuel-efficiency and a second VVT lookup-map corresponding to realize minimum knocking. In an aspect, the memory 30 may store one or more computer-readable instructions or routines, which may be fetched and executed to control the inlet valves and the exhaust valves of the engine to achieve the variable valve timing VVT. The memory 30 may include any non-transitory storage device including, for example, volatile memory such as RAM, or non-volatile memory such as EPROM, flash memory, and the like.
The control unit 40 may be implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, logic circuitries, and/or any devices that manipulate data based on operational instructions. Among other capabilities, the control unit 40 is configured to fetch and execute computer-readable instructions stored in the memory 30.
The control unit 40 is communicatively coupled to the sensor 20, the memory 30, the inlet valves, and the exhaust valves. The control unit 40 comprises a knocking detection module 40a and a selection module 40b. The knocking detection module 40a is configured to receive the sensed signal from the sensor 20. The knocking detection module 40a is configured to process the sensed signal to determine the severity of the knocking of the engine. The selection module 40b is configured to select one of the first VVT lookup-map and the second VVT lookup-map based on the severity of the knocking of the engine. The control unit 40 is configured to control at least one of the inlet valves and the exhaust valves of the engine with valve timings of the selected VVT lookup-map. Figure 2 illustrates graphs relating valve timing adjustment based on knocking tendencies and the processed knock sensor signal.
In an embodiment, the control unit 40 is configured to select the first VVT lookup-map when there is a low severity of the knocking of the engine. In an alternate embodiment, the control unit 40 is configured to select the second VVT lookup-map when there is a high severity of the knocking of the engine.
In an embodiment, the control unit 40 further comprises a weighing module 40c and a VVT lookup-map generator 40d.
The weighing module 40c is configured to determine a weightage factor for an intermediate severity of the knocking of the engine. The VVT lookup-map generator 40d is configured to receive the weightage factor, the first VVT lookup-map, and the second VVT lookup-map from the memory 30. The VVT lookup-map generator 40d is configured to generate a third VVT lookup-map accordingly based on the weightage factor, the first VVT lookup-map and the second VVT lookup-map. The control unit 40 is configured to control at least one of the inlet valves and the exhaust valves of the engine with valve timings based on the generated third VVT lookup-map for the intermediate severity of the knocking of the engine.
In an embodiment, the VVT lookup-map generator 40d comprises a multiplier module 40d-1 and a summing module 40d-2, and the VVT lookup-map generator 40d is configured to:
• multiply, by the multiplier module 40d-1, the weightage factor with the first VVT lookup-map to obtain a weighted first VVT lookup-map;
• multiply, by the multiplier module 40d-1, the weightage factor with the second VVT lookup-map to obtain a weighted second VVT lookup-map; and
• sum, by the summing module 40d-2, the weighted first VVT lookup-map and the weighted second VVT lookup-map to obtain a third VVT lookup-map.
In an embodiment, the control unit 40 is configured to control valve timing depending on operating conditions of the engine. In an aspect, the operating conditions of the engine include one of a steady state condition and/or a dynamic state condition.
In an embodiment, the first VVT lookup-map, the second VVT lookup-map, and the third VVT lookup-map include valve timings corresponding to each of an engine-speed and an engine-load.
Figure 4 illustrates a variable valve timing VVT control method 400 for an engine having inlet valves and exhaust valves. The order in which the method 400 is described is not intended to be construed as a limitation, and any number of the described method steps can be combined in any appropriate order to carry out the method 400 or an alternative method. Additionally, individual steps may be deleted from the method 400 without departing from the scope of the subject matter described herein. The method 400 comprises:
• At step 402: the method 400 includes sensing, by at least one sensor 20, vibrations of the engine caused due to uneven combustion of fuel and to generate a sensed signal.
• At step 404: the method 400 includes storing, in a memory 30, a first VVT lookup-map corresponding to realize a fuel-efficiency and a second VVT lookup-map corresponding to realize a minimum knocking.
• At step 406: the method 400 includes receiving, by a knocking detection module 40a of a control unit 40, the sensed signal from the sensor 20.
• At step 408: the method 400 includes processing, by the knocking detection module 40a, the sensed signal to determine severity of the knocking of the engine.
• At step 410: the method 400 includes selecting, by a selection module 40b of the control unit 40, one of the first VVT lookup-map and the second VVT lookup-map based on the severity of the knocking of the engine.
• At step 412: the method 400 includes controlling, by the control unit 40, at least one of the inlet valves and the exhaust valves having valve timings of the selected lookup-map.
In an embodiment, the method 400 further comprises a method step of selecting the first VVT lookup-map when there is a low severity of the knocking of the engine. In an embodiment, the method 400 further comprises a method step of selecting the second VVT lookup-map when there is a high severity of the knocking of the engine.
In an embodiment, the method 400 further includes method steps of:
• determining, by a weighing module 40c of the control unit 40, a weightage factor for an intermediate severity of the knocking of the engine;
• receiving, by a VVT lookup-map generator 40d of the control unit 40 the weightage factor, the first VVT lookup-map, and the second VVT lookup-map;
• generating, by the VVT lookup-map generator 40d of the control unit 40, a third VVT lookup-map; and
• controlling, by the control unit 40, at least one of the inlet valves and the exhaust valves having valve timings based on the generated third VVT lookup-map for the intermediate severity of the knocking of the engine.
In an embodiment, the method 200 further comprises a method step of generating the third VVT lookup-map includes following steps:
• multiplying, by a multiplier module 40d-1, the weightage factor with the first VVT lookup-map to obtain a weighted first VVT lookup-map;
• multiplying, by the multiplier module 40d-1, the weightage factor with the second VVT lookup-map to obtain a weighted second VVT lookup-map; and
• summing, by a summing module 40d-2, the weighted first VVT lookup-map and the weighted second VVT lookup-map to obtain the third VVT lookup-map.
In a working example, fuel quality used in engines is generally defined by Research Octane Number (RON) and it plays an important role in engine knocking tendency wherein high RON fuel is less prone to knock, and low RON fuel is more prone to knock. The system 100 is configured to select the first VVT lookup-map for adjusting the valve timings when there is a low severity of the knocking of the engine, in particular this case happens for a high value RON fuel. The system 100 is configured to select the second VVT lookup-map for adjusting the valve timings when there is a high severity of the knocking of the engine, in particular, this case happens for a low value RON fuel. The system 100 is configured to select the third VVT lookup-map for adjusting the valve timings when there is an intermediate severity of the knocking of the engine, in particular, this case happens for a fuel which is between low and high RON value. The present system 100 facilitates the engine to operate on valve timing best for rapid torque generation and this can be shown in Figure 3 which illustrates a graph showing dynamic torque comparison with higher & lower RON fuel.
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.
TECHNICAL ADVANCEMENTS
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of a variable valve timing control system for the engine and a method thereof, which can:
• adjust engine valve based on engine knocking tendency;
• generate separate valve timing for steady state and dynamic operation for different engine-knocking tendencies;
• achieve maximum engine protection for a fuel with more knocking tendency; and
• achieve maximum engine performance for a fuel with less knocking tendency.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The foregoing description of the specific embodiments so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
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 disclosure to achieve one or more of the desired objects or results.
Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments 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 variable valve timing (VVT) control system (100) for an engine having inlet valves and exhaust valves, the system (100) comprises:
a. at least one sensor (20) mounted on an engine block of the engine to sense vibrations of the engine caused due to uneven combustion of fuel and to generate a sensed signal;
b. a memory (30) configured to store a first VVT lookup-map corresponding to realize a fuel efficiency and a second VVT lookup-map corresponding to realize a minimum knocking; and
c. a control unit (40) communicatively coupled to said at least one sensor (20), said memory (30), said inlet valves, and said exhaust valves, said control unit (40) comprises:
i. a knocking detection module (40a) configured to receive the sensed signal from said at least one sensor (20) and to process the sensed signal to determine the severity of the knocking of the engine; and
ii. a selection module (40b) configured to select one of the first VVT lookup-map and the second VVT lookup-map based on the severity of the knocking of the engine,
wherein said control unit (40) is configured to control at least one of said inlet valves and said exhaust valves with valve timings of the selected VVT lookup-map.
2. The system (100) as claimed in claim 1, wherein said control unit (40) is configured to select the first VVT lookup-map when there is a low severity of the knocking of the engine.
3. The system (100) as claimed in claim 1, wherein said control unit (40) is configured to select the second VVT lookup-map when there is a high severity of the knocking of the engine.
4. The system (100) as claimed in claim 1, wherein said control unit (40) further comprises:
a. a weighing module (40c) configured to determine a weightage factor for an intermediate severity of the knocking of the engine; and
b. a VVT lookup-map generator (40d) configured to receive the weightage factor, the first VVT lookup-map, and the second VVT lookup-map, and to generate a third VVT lookup-map accordingly;
wherein the control unit (40) is configured to control at least one of said inlet valves and said exhaust valves with valve timings based on the generated third VVT lookup-map for the intermediate severity of the knocking of the engine.
5. The system (100) as claimed in claim 4, wherein said VVT lookup-map generator (40d) comprises a multiplier module (40d-1) and a summing module (40d-2), and wherien said VVT lookup-map generator (40d) is configured to:
i. multiply, by the multiplier module (40d-1), the weightage factor with the first VVT lookup-map to obtain a weighted first VVT lookup-map;
ii. multiply, by the multiplier module (40d-1), the weightage factor with the second VVT lookup-map to obtain a weighted second VVT lookup-map; and
iii. sum, by the summing module (40d-2), the weighted first VVT lookup-map and the weighted second VVT lookup-map to obtain the third VVT lookup-map.
6. The system (100) as claimed in claim 1, wherein said control unit (40) is configured to control valve timing depending on operating conditions of the engine, and wherein the operating conditions of the engine include one of a steady state condition and/or a dynamic state condition.
7. The system (100) as claimed in claim 1, wherein the first VVT lookup-map, the second VVT lookup-map, and the third VVT lookup-map include valve timings corresponding to each of an engine-speed and an engine-load.
8. A variable valve timing (VVT) control method (400) for an engine having inlet valves and exhaust valves, the method (400) comprising:
i. sensing (402), by at least one sensor (20), vibrations of the engine caused due to uneven combustion of fuel and to generate a sensed signal;
ii. storing (404), in a memory (30), a first VVT lookup-map corresponding to realize a fuel efficiency and a second VVT lookup-map corresponding to realize a minimum knocking;
iii. receiving (406), by a knocking detection module (40a) of a control unit (40), the sensed signal from said sensor (20);
iv. processing (408), by said knocking detection module (40a), the sensed signal to determine severity of the knocking of the engine;
v. selecting (410), by a selection module (40b) of said control unit (40), one of the first VVT lookup-map and the second VVT lookup-map based on the severity of the knocking of the engine; and
vi. controlling (412), by said control unit (40), at least one of said inlet valves and said exhaust valves with valve timings of the selected lookup-map.
9. The method (200) as claimed in claim 8 includes a method step of selecting the first VVT lookup-map when there is a low severity of the knocking of the engine.
10. The method (200) as claimed in claim 8 includes a method step of selecting the second VVT lookup-map when there is a high severity of the knocking of the engine.
11. The method (200) as claimed in claim 8 further includes method steps of:
i. determining, by a weighing module (40c) of said control unit (40), a weightage factor for an intermediate severity of the knocking of the engine;
ii. receiving, by a VVT lookup-map generator (40d) of said control unit (40), the weightage factor, the first VVT lookup-map, and the second VVT lookup-map;
iii. generating, by said VVT lookup-map generator (40d) of said control unit (40), a third VVT lookup-map; and
iv. controlling, by said control unit (40), at least one of said inlet valves and said exhaust valves with valve timings based on the generated third VVT lookup-map for the intermediate severity of the knocking of the engine.
12. The method (200) as claimed in claim 11, wherein method step of generating the third VVT lookup-map includes following steps:
i. multiplying, by a multiplier module (40d-1), the weightage factor with first VVT lookup-map to obtain a weighted first VVT lookup-map;
ii. multiplying, by said multiplier module (40d-1), the weightage factor with second VVT lookup-map to obtain a weighted second VVT lookup-map; and
iii. summing, by a summing module (40d-2), the weighted first VVT lookup-map and the weighted second VVT lookup-map to obtain the third VVT lookup-map.

Dated this 14th day of February, 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