Claims:We Claim:
1. A method (100) to control the combustion in an engine, said method (100) comprises:
estimating (101)the fuel quantity to be injected from a fuel tank based on speed of the crank shaft;
sensing (102) the airflow quantity from an intake manifold of said engine by a sensor;
processing (103) the estimated fuel and the sensed airflow quantity to determine the value of lambda; and
controlling (104) said combustion in said engine by adjusting the fuel quantity based on the determined value of lambda.
2. The method (100) as claimed in claim 1, wherein said speed of the crank shaft is measured by torque estimator;
3. The method (100) as claimed in claim 2, wherein a torque is calculated from said speed of crankshaft.
4. The method (100) as claimed in claim 3, wherein the fuel quantity is estimated based on said torque.
5. The method (100) as claimed in claim 1, wherein said sensor is an air flow sensor.
, Description:Complete Specification:
The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed.
Field of the invention
[0001] The invention here relates to a method to control combustion in an engine.

Background of the invention
[0002] A lambda sensor is an electronic device that measures the proportion of oxygen in the gas or liquid being analysed. The most common application is to measure the exhaust-gas concentration of oxygen for internal combustion engines in automobiles and other vehicles. In order to calculate dynamically adjust the air fuel ratio so that catalytic converters can work optimally, and determine whether the converter is performing properly or not. Drivers also use a similar device to measure the partial pressure of oxygen.

[0003] The patent application IN02236DE2014 discloses the subject matter relates to method for lambda and ignition angle control for a combustion in an internal combustion engine having at least one 5 cylinder. Wherein an optimized air-fuel ratio or an optimized ignition angle is determined from a characteristic, from which an estimated value for a torque is determined.

Brief description of the accompanying drawings:
[0004] Different modes of the invention are disclosed in detail in the description and illustrated in the accompanying drawing:
[0005] FIG. 1 illustrates a method 100 to control a combustion is an engine according to an embodiment in an invention;

Detailed description of the embodiments
[0006] Figure 1 shows method 100 to control the combustion in an engine. The method 100 comprises of following steps: - In step S1, the fuel quantity to be injected from fuel tank in an engine is estimated 101 based on the speed of the crankshaft. In step S2, a sensor senses 102 the airflow rate from intake manifold of an engine. In step S3, to determine the value of Lambda, the estimated fuel quantity and sensed airflow rate is processed 103. In step S4, based on the value of lambda, the fuel quantity to be injected is adjusted therefore controlling 104 the combustion in an engine.

[0007] The speed of the crankshaft is calculated by the torque estimator like function such as torque estimation by oscillation or by position of combustion so that the actual fuel quantity is estimated 101 and combustion is controlled 104 in an engine. The torque is directly proportional to the speed of the crankshaft. As the speed of the crankshaft increases, the torque increases and vice versa. The torque estimator measures the speed of the crankshaft, which in turn calculates the value of torque and based on the value of torque the fuel quantity is estimated 101.

[0008] The air flow rate is sensed 102 by the air flow sensor. This is the air entering from the intake manifold in an engine. The air mass information is necessary for the engine control unit to balance and deliver the correct fuel mass to the engine.

[0009] The value of lambda is calculated after processing 103 the fuel quantity and the air flow rate. The value of the lambda is value calculated from a ratio of air-fuel mixture. Once the value of lambda is calculated, then the fuel quantity to be injected i.e. the injection quantity is adjusted at the intake manifold and therefore the combustion is controlled 104. The lambda value based on the air fuel ratio is already existing and stored in an engine say actual lambda and that is how the injection quantity is maintained. The value of Lambda calculated after processing 103 is compared to actual lambda already stored in the engine and based on the variation in the lambda value, the fuel quantity is adjusted and therefore the combustion is controlled 104 in an engine.

[0010] Here as disclosed above, once the injection quantity is determined based on the variation in lambda value then that injection quantity is made to be injected into the engine. In addition, since the actual lambda value is stored so it is easier to find the variation between the actual lambda value and the obtained value. Let say for example, there is a particular injection quantity defined for actual lambda value so after the value of lambda is obtained, the injection quantity is changed based on the obtained lambda value. Therefore the combustion is controlled by injecting the actual injection quantity into the intake manifold of an engine.

[0011] The value of lambda is calculated based on ratio of air and fuel mixture and the combustion process is controlled. The Lambda is used to control the soot emission in the engine. The disclosure disclosed above helps the engine to have a controlled combustion process so that the soot emission is less or controlled. By using this method, the performance of the engine is improved by less amount of exhaust gas.

[0012] It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.