The present disclosure, in general relates to a bi-fuel (BF) vehicle and specifically relates to fuel adaption systems and methods for controlling fuel supply during idling conditions under different climatic conditions in the bi-fuel (BF) vehicle.
BACKGROUND
[0002] Generally, the term idling refers to the continuous operation of a vehicle's main propulsion engine while the vehicle is stopped. Idling is common in traffic conditions, especially during urban driving, such as at traffic lights or in stop-and-go driving during traffic congestion. However, idling periods in traffic are relatively short. There is more concern over long periods of idling while the vehicle is parked or in traffic congestion condition. This may have more of an adverse environmental impact and be a source of significant additional—and often unnecessary—fuel consumption.
[0003] In current system, when the vehicle is in the position of idling in hot weather [ 40°C ambient temperature], then the temperature under the hood rises above 50°C. Due to higher under hood temperature, the CNG density reduces, and the ECU determines that the system is getting leaner than the set stoichiometry. Then the ECU increases the idle fuel adaptation, to maintain the system at set stoichiometry.
[0004] Then after long hot idle, the engine is switched off and the vehicle is allowed to soak overnight. During overnight soak condition, the under-hood temperature of the engine along with the CNG temp is reduced to ambient temperature. But the Idle fuel is adapted to higher side [+16%] as it was required during hot operation. So, after Cold Start Operation, when the vehicle comes to idling state, 16% richness corresponding to hot idle gets applied @ cold condition. This excess richness causes the engine to dip below desired idle Rpm and causes engine to stall.

[0005] In addition, the supply of the richer/leaner mixture through the fuel injector also depends upon the injector clogging, gumming, dripping in single or multiple CNG / Pet injector.
[0006] So, all the above -mentioned factors result in a fuel consumption which is not according to the stoichiometric ratio that in turn results in the increment in NOx/CO/THC emission at the same time as higher richness may lead to misfire in CNG Mode.
[0007] Specifically, during the combustion of fuel in an internal combustion engine, it is necessary to manage an appropriate mixing ratio between the intake air amount and the fuel, so that the air-fuel ratio may help in overcoming all the above-mentioned problems and thereby increase the efficiency of the engine.
[0008] Hence, there is a requirement of a fuel adaption systems and methods for controlling fuel supply during idling conditions under different climatic conditions in the bi-fuel (BF) vehicle.
OBJECTS OF THE DISCLOSURE
[0009] Some of the objects of the present disclosure, which at least one embodiment satisfy, are listed herein below.
[0010] It is a general or primary object of the present disclosure to provide a system and a method for controlling fuel supply in a bi-fuel (BF) vehicle during idling under different climatic conditions.
[0011] It is another object of the present disclosure to provide the system and the method that enhances vehicle performance.
[0012] It is another object of the present disclosure to provide the system and the method that reduces the fuel consumption.
[0013] It is further object of the present disclosure to provide the system and the method that reduces the fuel consumption when operating the

engine on different fuels, such as gasoline or Compressed Natural gas (CNG).
[0014] It is yet further object of present disclosure to provide the system and the method to control a plurality of injectors connected to the fuel rail for supplying the fuel based on the retrieved oxygen-adapted fuel amount to maintain the set stoichiometric air-to-fuel ratio.
[0015] These and other objects and advantages will become more apparent when reference is made to the following description and accompanying drawings.
SUMMARY
[0016] This summary is provided to introduce concepts related to a bi-fuel (BF) vehicle and specifically relates to fuel adaption systems and methods for controlling fuel supply during idling conditions under different climatic conditions in the bi-fuel (BF) vehicle.
[0017] The concepts are further described below in the detailed description. This summary is neither intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
[0018] In accordance with an embodiment, the present disclosure provides a system for controlling fuel supply during idling conditions of a bi-fuel (BF) vehicle, the system comprising a fuel rail temperature sensor to sense temperature inside a fuel rail during an idle hot condition or an idle cold condition of the engine of the vehicle, respectively; an air intake temperature sensor to sense temperature at the air intake port during the idle hot condition or the idle cold condition of the engine of the vehicle, respectively; and a BF electronic control unit (ECU), coupled to the fuel rail temperature sensor and the air intake temperature sensor, to: receive temperature signals from the fuel rail temperature sensor and the air intake temperature sensor during the idle hot condition or the idle cold condition

of the engine of the vehicle, respectively, retrieve a temperature-adapted fuel amount stored in a learning database for temperatures indicated by the temperature signals, and control a plurality of injectors connected to the fuel rail for supplying the fuel based on the retrieved temperature-adapted fuel amount to maintain a set stoichiometric air-to-fuel ratio.
[0019] In an aspect, the BF-ECU is to control the plurality of injectors by ascertaining whether the oxygen-adapted fuel amount is lying near a limiting value of the set stoichiometric air-to-fuel ratio; and based on ascertainment, instantaneously shifting the limit value in predefined steps for allowing the fuelling to stabilize.
[0020] In an aspect, the BF-ECU is to shift the limit value in predefined steps by : determining whether the oxygen-adapted fuel amount resulting into increase or decrease in the amount of fuel; based on the determining, increasing or decreasing the limit value by 10% to accommodate fuelling deficiency; and subsequently increasing or decreasing the limit value by 5 % for allowing the fuelling to stabilize.
[0021] In accordance with an embodiment, the present disclosure provides a method for controlling fuel supply during idling conditions of a bi-fuel (BF) vehicle, the method comprising sensing, by a fuel rail temperature sensor, temperature inside a fuel rail during an idle hot condition or an idle cold condition of the engine of the vehicle, respectively; sensing, by an air intake temperature sensor , temperature at the air intake port during the idle hot condition or the idle cold condition of the engine of the vehicle, respectively; and receiving, by a BF electronic control unit (ECU), temperature signals from the fuel rail temperature sensor and the air intake temperature sensor during the idle hot condition or the idle cold condition of the engine of the vehicle, respectively, retrieving, by the BF-ECU, a temperature-adapted fuel amount stored in a learning database for temperatures indicated by the temperature signals, and controlling, by the BF-ECU , a plurality of injectors connected to the fuel rail for supplying the

fuel based on the retrieved temperature-adapted fuel amount as saved in the BF - ECU as previous events, to maintain a set stoichiometric air-to-fuel ratio.
[0022] To further understand the characteristics and technical contents of the present subject matter, a description relating thereto will be made with reference to the accompanying drawings. However, the drawings are illustrative only but not used to limit the scope of the present subject matter.
[0023] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.
BRIEF DESCRIPTION OF FIGURES
[0024] The illustrated embodiments of the present disclosure will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of devices, systems, and processes that are consistent with the subject matter as claimed herein, wherein:
[0025] FIG.1 illustrates a block diagram of a system 100 for controlling fuel supply during idling conditions of a bi-fuel (BF) vehicle in accordance with an embodiment of the present disclosure.
[0026] FIG.2 illustrates a block diagram of a system 100 that shows the interconnection between various components in accordance with an embodiment of the present disclosure.
[0027] FIG.3 illustrates a block diagram of an ECU unit 106 in accordance with an embodiment of the present disclosure.

[0028] FIG.4 illustrates the step-by-step execution of the method 400 for controlling fuel supply during idling conditions of a bi-fuel (BF) vehicle through the system 100 in accordance with an embodiment of the present disclosure.
[0029] FIG.5 illustrates a graph that defines the working of the system 100 for controlling fuel supply during idling conditions of a bi-fuel (BF) vehicle in accordance with an embodiment of the present disclosure.
[0030] The figures depict embodiments of the present subject matter for the purpose of illustration only. A person skilled in the art will easily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION
[0031] A few aspects of the present disclosure are explained in detail below with reference to the various figures. Example implementations are described to illustrate the disclosed subject matter, not to limit its scope, which is defined by the claims. Those of ordinary skill in the art, will recognize a number of equivalent variations of the various features provided in the description that follows.
EXEMPLARY IMPLEMENTATIONS
[0032] While the present disclosure may be embodied in various forms, which are shown in the drawings, and will hereinafter be described, some exemplary and non-limiting embodiments, with the understanding that the present disclosure is to be considered an exemplification of the disclosure and is not intended to limit the disclosure to the specific embodiments illustrated. Not all of the depicted components described in this disclosure may be required, however, and some implementations may include additional, different, or fewer components from those expressly described in this disclosure. Variations in the arrangement and type of the components

may be made without departing from the scope of the claims as set forth herein.
[0033] FIG.1 illustrates a block diagram of a system 100 for controlling fuel supply during idling conditions of a bi-fuel (BF) vehicle in accordance with an embodiment of the present disclosure.
[0034] The system comprises a plurality of temperature sensors. The first temperature sensor 102 which determines the fuel rail temperature. Here the vehicle is bi-fuel vehicle that uses either gasoline or CNG at a time. Therefore, the temperature sensor 102 determines the fuel rail temperature accordingly. It further comprises the second temperature sensor used to determine the air intake temperature and it is also called as air intake temperature sensor 104. It further comprises a sensor 110 that is employed to determine the oxygen content in the exhaust gas before the catalytic convertor. It further employs a sensor 112 that is employed to determine the oxygen content in the exhaust gas after the catalytic convertor. It also included multiple fuel injectors 108 that are used for injecting fuels in the multiple cylinders.
[0035] The system further comprises an ECU unit 106 having an ECU module 106A that is used for collecting the data from the various sensors. It further comprises a learning module 106B to calculate the results based on the given data. It further comprises a database module 106C that is used for storing the calculated data in the database which can be retrieved later when the same condition arises.
[0036] FIG.2 illustrates a block diagram of a system 100 that shows the interconnection between various components in accordance with an embodiment of the present disclosure.
[0037] As per the block diagram, the system 100 comprises an intake manifold 202 which is further connected to the intake runner having multiple tubes that helps in evenly distributing the air coming into the engine 204 to

all the cylinders. This air is generally used during the first stroke of the combustion process. The intake manifold 202 also helps cool down the cylinders to prevent the engine from overheating.
[0038] As mentioned, the engine 204 comprises plurality of cylinders, therefore to inject the fuel in equal amount in the plurality of cylinders, a fuel rail is needed. The fuel rail employs multiple fuel injectors 108 to inject fuel in multiple cylinders. As mentioned above, the vehicle is bi- fuel vehicle. Hence, one of the either of the fuel gasoline or the CNG is used, at a time. Therefore, the injectors inject fuel accordingly. In addition, the temperature sensor 102 is also installed over the fuel rail to determine the temperature, when either gasoline or CNG is used as a fuel. It also comprises the temperature sensor 104 installed over the multiple intake runner to determine the air intake temperature.
[0039] After burning of fuel in the engine, the exhaust gas is supplied through the exhaust pipe 206 having a catalytic convertor 208 installed in between. The catalytic converter 208 is an exhaust emission control device that converts highly toxic gases and pollutants in exhaust gas to less- toxic pollutants. It further comprises the front oxygen sensor 110 installed before the catalytic convertor 208 and the rear oxygen sensor 112 installed after the catalytic convertor 208.lt further comprises the ECU unit 106 that collects the data from the various sensors, then calculate the data and stores the data accordingly.
[0040] FIG.3 illustrates a block diagram of an ECU unit 106 in accordance with an embodiment of the present disclosure.
[0041] The ECU unit 106 comprises an EC module that collects the data from the sensors and stores in the memory 106M. The processor 106P of the ECU Unit process the collected data, and then the learning module 106B calculates the data based on the received data. The calculated data is then stored in the learning database 106C. It also comprises an interface 1061 that shows the received data and resultant data.

WORKING OF THE DISCLOSURE
[0042] FIG.4 illustrates the step-by-step execution of the method 400 for controlling fuel supply during idling conditions of a bi-fuel (BF) vehicle through the system 100 in accordance with an embodiment of the present disclosure.
[0043] As mentioned above, the system 100 comprising the fuel rail temperature sensor 102 to sense temperature inside a fuel rail during an idle hot condition or an idle cold condition of the engine of the vehicle, respectively. Here the vehicle is bi-fuel using either gasoline or CNG at a particular instant of time.
[0044] At step 402, the temperature sensor 102 determines the temperature based on the fuel used.
[0045] It further comprises the air intake temperature sensor 104 to sense temperature at the air intake port during the idle hot condition or the idle cold condition of the engine of the vehicle, respectively.
[0046] At step 404, the air intake temperature sensor 104 determines the air intake temperature.
[0047] It further comprises an ECU unit 106 that is coupled to the fuel rail temperature sensor 102 and the air intake temperature sensor 104 having an ECU module 106A.
[0048] At step 406, the ECM module 106A of the ECU unit 106 receives temperature signals from the fuel rail temperature sensor 102 and the air intake temperature sensor 104 during the idle hot condition or the idle cold condition of the engine of the vehicle, respectively.
[0049] After that, the learning module 106B calculates the stoichiometric ratio of air/fuel under that particular condition and temperature. The learning module 106B further calculates the stoichiometric ratio of air/fuel under

different condition, and temperature, but only during idling situation. This calculated data is stored in the database 106C of the ECU unit.
[0050] So, when the same condition, and the temperature arises, as per the stored data
[0051] At step 408, the ECU module 106A retrieves a temperature-adapted fuel amount stored in a learning database 106C for temperatures indicated by the temperature signals, and
[0052] At step 410, the ECU unit 106 controls a plurality of fuel injectors 108 connected to the fuel rail for supplying the fuel based on the retrieved temperature-adapted fuel amount to maintain a set stoichiometric air-to-fuel ratio.
[0053] This can be explained by an example here, the present disclosure defines the system and the method for reducing the NOx/CO/ THC emission caused due to lean/ rich air and fuel mixture combustion arises either due to injector clogging, gumming, dripping in single or multiple CNG / Pet injector at the same time.
In this case at Step 1- The vehicle ECU determines the idling condition, it checks for the intake air temperature in CNG mode or gasoline mode (depends upon the type of fuel used at that particular instant of time, at present CNG is taken into consideration).
Step 2- Then the ECU allocates the Idle fuel adaptation respective to the present intake air temperature at which the engine is operating in CNG Mode.
Step 3- Thus after the completion of long idling under hot/ cold condition and the engine is stopped, the ECU allocates the air/fuel amount corresponding to that particular higher/ lower intake temp.
Step 4- Thus when the engine is restarted after overnight soak in cold/ hot ambient and restarted next morning/ event, then the ECU

allocates the air /fuel amount corresponding to cold/ hot intake air to the idling.
Step 5 - Thus when the engine reaches to any of the above-mentioned particular condition at any particular instant of time, then the ECU supplies the same of amount of air /fuel that was earlier fixed by the ECU under certain condition.
[0054] In accordance with the graph as shown in FIG.5, during the idling condition, the ECU of the proposed system operates the injector in providing high amount of adjustment based on front and rear oxygen sensor feedback, in order to operate engine on desired stoichiometry. During the event of fuel adjustment, the ECU checks if the adjustment done lies in the range vary in between the min and the max guard / threshold limit defined in the system. If the ECU determines that the fuel correction saved in ECU, vehicle operation is within ± 1% of guard value, then the ECU increases the guard value in desired direction or as per requirement [rich/lean] with an increment of 10 % instantaneously.
ADVANTAGES
[0055] The proposed system and method efficiently control fuel supply in a bi-fuel (BF) vehicle during idling under different climatic conditions. It enhances the vehicle performance and reduces the fuel consumption. It also reduces the fuel consumption when operating the engine on different fuels, such as gasoline or Compressed Natural gas (CNG). It also efficiently controls a plurality of injectors connected to the fuel rail for supplying the fuel based on the retrieved oxygen-adapted fuel amount to maintain the set stoichiometric air-to-fuel ratio.
[0056] The above description does not provide specific details of the manufacture or design of the various components. Those of skill in the art

are familiar with such details, and unless departures from those techniques are set out, techniques, known, related art or later developed designs and materials should be employed. Those in the art are capable of choosing suitable manufacturing and design details.
[0057] Further, the terminology used herein, is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. It will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be combined into other systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may subsequently be made by those skilled in the art without departing from the scope of the present disclosure as encompassed by the following claims.
[0058] The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.
[0059] It will be appreciated that variants of the above-disclosed and other features and functions, or alternatives thereof, may be combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.

CLAIM:

1. A system (100) for controlling fuel supply during idling conditions of
a bi-fuel (BF) vehicle, the system (100) comprising:
a fuel rail temperature sensor (102) to sense temperature inside a fuel rail during an idle hot condition or an idle cold condition of the engine of the vehicle respectively;
an air intake temperature sensor (104) to sense temperature at the air intake port during the idle hot condition or the idle cold condition of the engine of the vehicle, respectively; and
a BF electronic control unit (ECU) (106), coupled to the fuel rail temperature sensor (102) and the air intake temperature sensor (104), to:
receive temperature signals from the fuel rail temperature sensor (102) and the air intake temperature sensor (104) during the idle hot condition or the idle cold condition of the engine of the vehicle, respectively,
retrieve a temperature-adapted fuel amount stored in a learning database (106C) for temperatures indicated by the temperature signals, and
control a plurality of injectors (108) connected to the fuel rail for supplying the fuel based on the retrieved temperature-adapted fuel amount to maintain a set stoichiometric air-to-fuel ratio.
2. The system as claimed in claim 1, wherein the BF-ECU (106) is to
control the plurality of injectors (108) by:
ascertaining whether the oxygen-adapted fuel amount is lying near a limiting value of the set stoichiometric air-to-fuel ratio; and

based on ascertainment, instantaneously shifting the limit value in predefined steps for allowing the fueling to stabilize.
3. The system (100) as claimed in claim 2, wherein the BF-ECU (106)
is to shift the limit value in predefined steps by:
determining whether the oxygen-adapted fuel amount resulting into increase or decrease in the amount of fuel;
based on the determining, increasing or decreasing the limit value by 10% to accommodate fueling deficiency; and
subsequently increasing or decreasing the limit value by 5 % for allowing the fueling to stabilize.
4. A method (400) for controlling fuel supply during idling conditions of
a bi-fuel (BF) vehicle, the method comprising:
sensing, by a fuel rail temperature sensor (102), temperature inside a fuel rail during an idle hot condition or an idle cold condition of the engine of the vehicle, respectively;
sensing, by an air intake temperature sensor (104), temperature at the air intake port during the idle hot condition or the idle cold condition of the engine of the vehicle, respectively; and
receiving, by a BF electronic control unit (ECU) (106), temperature signals from the fuel rail temperature sensor (102) and the air intake temperature sensor (104) during the idle hot/ cold condition or the idle hot/cold condition of the engine of the vehicle, respectively,
retrieving, by the BF-ECU (106), a temperature-adapted fuel amount stored in a learning database (106C) for temperatures indicated by the temperature signals, and

controlling, by the BF-ECU (106), a plurality of injectors (108) connected to the fuel rail for supplying the fuel based on the retrieved temperature-adapted fuel amount to maintain a set stoichiometric air-to-fuel ratio.
5. The method (400) as claimed in claim 4, wherein the controlling of
the plurality of injectors (108) comprises:
ascertaining whether the oxygen-adapted fuel amount is lying near a limiting value of the set stoichiometric air-to-fuel ratio; and
based on ascertainment, instantaneously shifting the limit value in predefined steps for allowing the fueling to stabilize.
6. The method (400) as claimed in claim 5, wherein the instantaneously
shifting of the limit value in predefined steps comprises:
determining whether the oxygen-adapted fuel amount resulting into increase or decrease in the amount of fuel;
based on the determining, increasing or decreasing the limit value by 10% to accommodate fueling deficiency; and
subsequently
increasing or decreasing the limit value by 5 % for allowing the fueling to stabilize.