FIELD OF INVENTION
The present invention relates to a method and a system for controlling quantity of fuel injected into an engine of a vehicle based on inter-vehicle distance in real-time, which can help in reducing the fuel consumption and thereby increase the fuel efficiency of the vehicle.
BACKGROUND OF THE INVENTION
Operating economics is one of the key business drivers of automotive industry. With regard to operating economics, fuel cost contributes a major portion in the vehicle lifecycle cost. In real-time traffic conditions, fuel efficiency is decreased due to frequent usage of brakes for decelerating the vehicle for safe vehicle movement. Accordingly, there is a need to avoid usage of brake and at the same time decelerate the vehicle depending upon the traffic conditions.
OBJECT OF INVENTION
One of the objects of the present invention is to control the quantity of fuel injected into an engine of a vehicle based on inter-vehicle distance thereby control the vehicle speed.
Another object of the present invention is to decelerate the vehicle speed by cutting off or reducing the fuel quantity injected into the engine based on the inter-vehicle distance information.
Yet another object of the present invention is to increase the fuel efficiency of a vehicle by controlling fuel injected quantity thereby reducing energy spent on frequent braking in real-time traffic scenarios.

SUMMARY OF THE INVENTION
The present invention relates to a system and method for controlling quantity of fuel injected into an engine of a vehicle based on inter-vehicle distance information. Based on inter-vehicle distance, the relative speed of the subject vehicle with respect to immediate vehicle traveling in front of it is computed. Depending on the relative speed and inter-vehicle distance, a decision is taken by the system whether to control the fuel injected quantity or not. If the decision is taken to control the quantity of fuel injected, then the system will transmit a control command to engine management system which will control the quantity of fuel injected into an engine. Fuel injected quantity is controlled till the desired relative speed is achieved.
Accordingly the present invention provides a method for controlling quantity of fuel injected into an engine of a vehicle based on inter-vehicle distance measured in real¬time, said method comprising the steps of
measuring in real-time the distance between said vehicle and another vehicle traveling in the front of said vehicle;
measuring in real-time the distance between said vehicle and other vehicles traveling on both the sides of said vehicle;
transmitting the measured front inter-vehicle distance and the side inter-vehicle distance to a computation and communication device at a pre determined time interval;
storing a pre determined front inter-vehicle distance, a pre-determined side inter-vehicle distance and pre determined time interval in a memory of said computation and communication device;
comparing the measured front inter-vehicle distance with said pre determined front inter-vehicle distance;

comparing the measured side inter-vehicle distance with said pre determined side inter-vehicle distance;
computing relative speed of said vehicle with respect to the vehicle traveling in the front of said vehicle only when the measured front inter-vehicle distance is less than or equal to the predetermined front inter-vehicle distance and the measured side inter-vehicle distance is less than or equal to the predetermined side inter-vehicle distance; and
controlling the quantity of fuel injected into the engine of said vehicle if said relative speed is greater than zero.
The present invention also provides a system for controlling quantity of fuel injected into an engine of a vehicle based on inter-vehicle distance measured in real¬time, said system comprising
a first radar unit mounted in the front of said vehicle for measuring in real-time the distance between said vehicle and another vehicle traveling in the front of said vehicle;
a second radar unit mounted on both sides of said vehicle for measuring in real-time the distance between said vehicle and other vehicles traveling on the sides of said vehicle;
a computing and communication device comprising a memory for storing a predetermined front inter-vehicle distance, a predetermined side inter-vehicle distanceand a predetermined time intervel, a processing unit for comparing the measured front inter-vehicle distance with said pre determined front inter-vehicle distance and the measured side inter-vehicle distance with said pre determined side inter-vehicle distance and for computing relative speed of said vehicle with respect to the vehicle traveling in the front of said vehicle when the measured front inter-vehicle distance is less than or equal to the

predetermined front inter-vehicle distance and the measured side inter-vehicle distance is less than or equal to the predetermined side inter-vehicle distance; engine control unit for controlling the quantity of fuel injected into the engine based on a command signal received from computing and communication device.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure. 1 shows a preferred embodiment of a system according to the present invention.
Figure. 2 shows a flow chart explaining the method of operation of the system .
DETAILED DESCRIPTION OF THE DRAWINGS
A preferred system in accordance with the present invention is shown in figure 1.
The system of the present invention comprises at least the following components:
RADAR (Radio Detection and Ranging) units (A) mounted on the vehicle, which comprises at least transmitter, waveguide, duplexer, receiver, controller and communication interfaces;
Computing and communication device (B) mounted on the vehicle which comprises at least the processing unit, clock, memory, input and output control/data channels and intra-vehicle communication interface;
Engine Control Unit (C) mounted on the vehicle which comprises at least the intra-vehicle communication interface, input & output control/data channels, control mechanism for controlling the quantity of fuel injected into the engine.

The method of operation of the system is explained in the flow chart shown in Figure 2. The subject vehicle is the vehicle on which the invented system is operated through the method of the present invention.
The vehicle administrator determines or configures a predetermined front inter-vehicle distance i.e. the ideal distance which the administrator wish to maintain between the subject vehicle and the vehicle/object which is traveling in immediate front. The administrator also determines or configures a predetermined side inter-vehicle distance i.e. the ideal distance which the administrator wish to maintain between the subject vehicle and the vehicles which are traveling on both the sides. The administrator determines these distances based on various factors such as type of vehicle, nature of road conditions, traffic density etc. The preferred range for the predetermined front inter-vehicle distance can be between 10 meters (minimum) to 70 meters (maximum). Similarly the preferred range for the predetermined side inter-vehicle distance can be between 3 meters (minimum) to 20 meters (maximum).
Both of these aforementioned predetermined values are stored in the memory of computing and communication device (B) through its input data and control channels. The administrator can modify these predetermined values and enter the same in the memory.
RADAR units (A) are at least mounted on front and side portions of the subject vehicle. Using RADAR unit mounted on front and side portions, the front inter-vehicle distance and side inter-vehicle distance are measured in real-time. Real-time front and side inter-vehicle distance information is provided to the Computing and Communication device (B) through communication interfaces of RADAR unit (A) at predetermined time intervals defined by vehicle administrator. The preferred range for the predetermined

time intervals can be between 0.25 second (minimum) to 3 seconds (maximum). The administrator can modify this predetermined value and enter the same in the memory.
The measured front inter-vehicle distance and the side inter-vehicle distance are compared with the predetermined front inter-vehicle distance and the predetermined side inter-vehicle distance, respectively, which are stored in the memory of the computing and Communication device (B).
If the measured front inter-vehicle distance is less than or equal to the predetermined front inter-vehicle distance and the measured side inter-vehicle distance is less than or equal to the predetermined side inter-vehicle distance (configured by vehicle administrator), then the computing and communication device (B) decides to compute the relative speed of the subject vehicle with respect to the vehicle which is going in immediate front of it otherwise no action will be taken by the computing and communication device (B) to control fuel injected quantity.
If the measured side inter-vehicle distance is greater than the predetermined side inter-vehicle distance, the relative speed of the subject vehicle is not computed even though the measured front inter-vehicle distance is less than or equal to the predetermined front inter-vehicle distance. Side inter-vehicle distance is only used as one of the parameters for making the decision whether or not relative speed of the subject vehicle to be computed to control the fuel injection quantity.
The relative speed of the subject vehicle with respect to the vehicle which is traveling in immediate front of it is determined by the following method:


where
RS -> Relative speed of the said vehicle with respect to the vehicle which is
traveling in immediate front of said vehicle
t -> current time
At -> predetermined time interval (configured by vehicle administrator)
FID (t-At) ->Front Inter-vehicle distance at time (t-At)
FID (t) -> Front Inter-vehicle distance at time t
If the relative speed of the subject vehicle with respect to the vehicle which is traveling in immediate front of subject vehicle is greater than zero, then the Computing and Communication device (B) will decide to control the quantity of fuel injected into the engine of the vehicle otherwise no action will be taken by the Computing and Communication device (B) to control the fuel injection quantity.
Once the decision is taken on controlling the quantity of fuel injected into the engine of the vehicle, the Computing and Communication device (B) will provide a command signal to Engine Control Unit(C) through its intra-vehicle communication interface. Based on the command signal received, the Engine Control Unit(C) will control the quantity of fuel injected into the engine through its control mechanism. This can be carried out by controlling the time for which fiiel injection valve is open or closed.
The quantity of fuel injected into the engine is controlled until relative speed of the subject vehicle with respect to the vehicle which is traveling in immediate front of subject vehicle becomes less than or equal to zero which means that the subject vehicle is traveling in a speed which is less than or equal to the vehicle which is traveling in

immediate front of it. Relative speed is calculated and monitored by the Computing and Communication device (B) present in the subject vehicle in real-time.
If in case the driver presses the accelerator pedal when the Engine Control Unit (C) is controlling the fuel injection based on the command signal from the computing and communication device (B) based on inter-vehicle distance, the input from accelerator pedal of the driver will not be considered till relative speed (RS) becomes less than or equal to zero.
System of the present invention controls the quantity of fuel injected into the engine of a vehicle in such a way that the relative speed of the subject vehicle is not greater than the vehicle traveling in front of it. By this way, the method and system of the present invention helps in avoiding collision of subject vehicle with vehicle traveling in front. This also helps in reducing the braking energy needed for stopping the vehicle to avoid collision with a vehicle traveling in front.
The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the claimed invention. Various modifications and alterations to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the claimed invention. Thus, the claimed invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

1. A method for controlling quantity of fuel injected into an engine of a vehicle based on inter-vehicle distance measured in real-time, said method comprising the steps of
a) measuring in real-time the distance between said vehicle and another vehicle traveling in the front of said vehicle;
b) measuring in real-time the distance between said vehicle and other vehicles traveling on both the sides of said vehicle;
c) transmitting the measured front inter-vehicle distance and the side inter-vehicle distance to a computation and communication device at a pre determined time interval;
d) storing a pre determined front inter-vehicle distance, pre-determined side inter-vehicle distance and a predetermined time interval in a memory of said computation and communication device;
e) comparing the measured front inter-vehicle distance with said pre determined front inter-vehicle distance;
f) comparing the measured side inter-vehicle distance with said pre
determined side inter-vehicle distance;
g) computing relative speed of said vehicle with respect to the vehicle
traveling in the front of said vehicle only when the measured front inter-
vehicle distance is less than or equal to the predetermined front inter-
vehicle distance and the measured side inter-vehicle distance is less than or
equal to the predetermined side inter-vehicle distance; and
h) controlling the quantity of fuel injected into the engine of said vehicle if said relative speed is greater than zero.

2. The method as claimed in claim 1, wherein the quantity of fuel injected into
the engine of said vehicle is controlled until the relative speed becomes less
than or equal to zero.
3. The method as claimed in claim 1, wherein said predetermined time interval is
preferably between 0.25 seconds to 3 seconds.
4. The method as claimed in claim 1, wherein the predetermined front inter-
vehicle distance is preferably from 10 meters to 70 meters.
5. The method as claimed in claim 1, wherein the predetermined side inter-
vehicle distance is preferably from 3 meters to 20 meters.

where
RS -> Relative speed of the said vehicle with respect to the vehicle which is traveling
in immediate front of said vehicle
t -> current time
At -> predetermined time interval
FID (t-At) ->Front Inter-vehicle distance at time (t-At)
FID (t) -> Front Inter-vehicle distance at time t.
7. A system for controlling quantity of fuel injected into an engine of a vehicle based on inter-vehicle distance measured in real-time, said system comprising

a) a first radar unit mounted in the front of said vehicle for measuring in real¬time the distance between said vehicle and another vehicle traveling in the front of said vehicle;
b) a second radar unit mounted on both sides of said vehicle for measuring in real-time the distance between said vehicle and other vehicles traveling on the sides of said vehicle;

c) a computing and communication device comprising a memory for storing a predetermined front inter-vehicle distance, predetermined side inter-vehicle distance and a predetermined time interval, a processing unit for comparing the measured front inter-vehicle distance with said pre determined front inter-vehicle distance and the measured side inter-vehicle distance with said pre determined side inter-vehicle distance and for computing relative speed of said vehicle with respect to the vehicle traveling in the front of said vehicle when the measured front inter-vehicle distance is less than or equal to the predetermined front inter-vehicle distance and the measured side inter-vehicle distance is less than or equal to the predetermined side inter-vehicle distance;
d) engine control unit for controlling the quantity of fuel injected into the engine based on a command signal received from computing and communication device.
8. The system as claimed in claim 7, wherein said radar unit comprises transmitter, waveguide, duplexer, receiver controller and communication interfaces.

9. The system as claimed in claim 7, wherein the computing and communication device comprises processing unit, clock, memory, input & output control/data channels and intra-vehicle communication interface.
10. The system as claimed in claim 7, wherein said engine control unit comprises control mechanism for controlling the fuel quantity injected into the engine.
11. The system as claimed in claim 10, wherein the control mechanism comprises at least one valve for controlling the quantity of fuel injected into the engine.