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] This invention relates to an algorithm for varying a calibration of an engine, and more specifically to the algorithm for varying the calibration of the engine based on a density of bio-diesel that is filled in a fuel tank of a vehicle.

Background of the invention
[0002] CN 112177788 A describes an oil injection control system with bio-diesel ratio acquisition module. More specifically, the invention relates to the oil injection control system with the biodiesel ratio acquisition module. The control system comprises an oil tank, the biodiesel ratio acquisition module and an oil injection control module, wherein the biodiesel ratio acquisition module is connected with the oil tank and used for acquiring the ratio of biodiesel in the oil tank of a current vehicle. The oil injection control module is used for correcting an oil injection MAP according to the ratio of the biodiesel and controlling an automobile engine to inject oil. The biodiesel ratio acquisition module is connected with the oil injection control module, and a biodiesel density calculation method and a biodiesel ratio calculation method are embedded in the biodiesel ratio acquisition module and used for acquiring biodiesel ratio data. Compared with the prior art, the oil injection control system has the advantages that the accurate oil injection quantity can be guaranteed, and the oil injection control system is simple and convenient to use.

Brief description of the accompanying drawing
[0003] Figure 1 illustrates an algorithm for varying a calibration of an engine based on a density of bio-diesel that is filled in a fuel tank of a vehicle in one embodiment of the invention.

Detailed description of the embodiments
[0004] Figure 1 illustrates an algorithm 100 for varying a calibration of an engine based on a density of bio-diesel that is filled in a fuel tank of a vehicle. The algorithm 100 comprising the steps of determining 110 whether a level of fuel within the fuel tank of the vehicle is below a threshold level of fuel that is pre-determined by a user, determining 120 a set of boundary conditions including whether an exhaust gas recirculation system is in an off state, a throttle of the engine is fully open, the engine is in an idling mode, calibration parameters that are applied on the engine is unchanged, no other corrective functions in the engine are currently active, and a coolant temperature of coolant that flows through the engine if the level of fuel within the fuel tank of the vehicle is below a threshold level of fuel that is pre-determined by the user respectively. The algorithm comprises comparing 130 an exhaust gas temperature of exhaust gas upstream of a turbine with respect to a reference value of an expected exhaust gas temperature of exhaust gas upstream of the turbine, comparing 140 an exhaust gas temperature of exhaust gas upstream of a diesel oxidation catalyst with respect to a reference value of an expected exhaust gas temperature of exhaust gas upstream of the diesel oxidation catalyst, comparing 150 a stoichiometric ratio of fuel that flows through the engine with respect to a reference value of an expected stoichiometric ratio of fuel that flows through the engine, and comparing 160 a concentration of oxides of nitrogen that are present in the exhaust gas that flows from the engine with respect to a reference value of an expected concentration of oxides of nitrogen that are present in the exhaust gas that flows from the engine. The algorithm further comprises correcting 170 an energizing time of a solenoid coil of a fuel injector by a first constant value that is pre-determined by the user if one of the exhaust gas temperature of exhaust gas upstream of the turbine exceeds the reference value of the expected exhaust gas temperature of exhaust gas upstream of the turbine by a second user defined constant value, the exhaust gas temperature of exhaust gas upstream of the diesel oxidation catalyst exceeds the reference value of the expected exhaust gas temperature of exhaust gas upstream of the diesel oxidation catalyst by a third user defined constant value, the stoichiometric ratio of fuel that flows through the engine exceeds the reference value of the expected stoichiometric ratio of fuel that flows through the engine by a fourth user defined constant value, the concentration of oxides of nitrogen that are present in the exhaust gas that flows from the engine exceeds the reference value of the expected concentration of oxides of nitrogen that are present in the exhaust gas that flows from the engine by a fifth user defined constant value. The algorithm further comprises correcting 180 an air-fuel ratio of air and fuel that flow into an engine from an inlet manifold of the engine by a sixth constant value that is pre-determined by the user if one of the exhaust gas temperature of exhaust gas upstream of the turbine exceeds the reference value of the expected exhaust gas temperature of exhaust gas upstream of the turbine by the second user defined constant value, the exhaust gas temperature of exhaust gas upstream of the diesel oxidation catalyst exceeds the reference value of the expected exhaust gas temperature of exhaust gas upstream of the diesel oxidation catalyst by the third user defined constant value, the stoichiometric ratio of fuel that flows through the engine exceeds the reference value of the expected stoichiometric ratio of fuel that flows through the engine by the fourth user defined constant value, the concentration of oxides of nitrogen that are present in the exhaust gas that flows from the engine exceeds the reference value of the expected concentration of oxides of nitrogen that are present in the exhaust gas that flows from the engine by the fifth user defined constant value.

[0005] Figure 1 illustrates an algorithm 100 for varying a calibration of an engine based on a density of bio-diesel that is filled in a fuel tank of a vehicle. The algorithm 100 comprises the steps of determining 110 whether a level of fuel within the fuel tank of the vehicle is below a threshold level of fuel that is pre-determined by a user. If it is determined 110 that the level of fuel within the fuel tank of the vehicle is below the threshold level of fuel that is pre-determined by the user, a set of boundary conditions are determined 120 including whether an exhaust gas recirculation system is in an off state, a throttle of the engine is fully open, the engine is in an idling mode, calibration parameters that are applied on the engine is unchanged, no other corrective functions in the engine are currently active, and a coolant temperature of coolant that flows through the engine if the level of fuel within the fuel tank of the vehicle is below the threshold level of fuel that is pre-determined by the user. Once it is determined by the algorithm that these boundary conditions are satisfied, the algorithm compares an exhaust gas temperature of exhaust gas upstream of the turbine with respect to a reference value of an expected exhaust gas temperature of exhaust gas upstream of the turbine. The comparison of the exhaust gas temperature of exhaust gas upstream of the turbine with respect to the reference value of the expected exhaust gas temperature of exhaust gas upstream of the turbine yields a deviation of the exhaust gas temperature of exhaust gas upstream of the turbine from its reference value. The algorithm further compares an exhaust gas temperature of exhaust gas upstream of a diesel oxidation catalyst with respect to a reference value of an expected exhaust gas temperature of exhaust gas upstream of the diesel oxidation catalyst. The comparison of the exhaust gas temperature of exhaust gas upstream of the diesel oxidation catalyst with respect to the reference value of the expected exhaust gas temperature of exhaust gas upstream of the diesel oxidation catalyst yields a deviation of the exhaust gas temperature of exhaust gas upstream of the diesel oxidation catalyst from its reference value.

[0006] The algorithm comprises the steps of comparing a stoichiometric ratio of fuel that flows through the engine with respect to a reference value of an expected stoichiometric ratio of fuel that flows through the engine. The comparison of the stoichiometric ratio of fuel that flows through the engine with respect to the reference value of the expected stoichiometric ratio of fuel that flows through the engine yields a deviation of the stoichiometric ratio of fuel that flows through the engine from its reference value. The algorithm further compares a concentration of oxides of nitrogen that are present in the exhaust gas that flows from the engine with respect to a reference value of an expected concentration of oxides of nitrogen that are present in the exhaust gas that flows from the engine. The comparison of the concentration of oxides of nitrogen that are present in the exhaust gas that flows from the engine with respect to the reference value of the expected concentration of oxides of nitrogen that are present in the exhaust gas that flows from the engine yields a deviation of the concentration of oxides of nitrogen that are present in the exhaust gas that flows from the engine with respect to its reference value.

[0007] The algorithm further comprises the steps of correcting an energizing time of a solenoid coil of a fuel injector by a first constant value that is pre-determined by the user if the exhaust gas temperature of exhaust gas upstream of the turbine exceeds the reference value of the expected exhaust gas temperature of exhaust gas upstream of the turbine by a second user defined constant value. In an alternate exemplary embodiment, the energizing time of the solenoid coil of the fuel injector is corrected by the first constant valve that is pre-determined by the user if the exhaust gas temperature of exhaust gas upstream of the diesel oxidation catalyst exceeds the reference value of the expected exhaust gas temperature of exhaust gas upstream of the diesel oxidation catalyst by a third user defined constant value. In another alternate exemplary embodiment, the energizing time of the solenoid coil of the fuel injector is corrected by the first constant valve that is pre-determined by the user if the stoichiometric ratio of fuel that flows through the engine exceeds the reference value of the expected stoichiometric ratio of fuel that flows through the engine by a fourth user defined constant value. In yet another alternate exemplary embodiment, the energizing time of the solenoid coil of the fuel injector is corrected by the first constant valve that is pre-determined by the user if the concentration of oxides of nitrogen that are present in the exhaust gas that flows from the engine exceeds the reference value of the expected concentration of oxides of nitrogen that are present in the exhaust gas that flows from the engine by a fifth user defined constant value.

[0008] The algorithm further comprises the steps of correcting an air-fuel ratio of air and fuel that flow into an engine from an inlet manifold of the engine by a sixth constant value that is pre-determined by the user if the exhaust gas temperature of exhaust gas upstream of the turbine exceeds the reference value of the expected exhaust gas temperature of exhaust gas upstream of the turbine by the second user defined constant value. In an alternate exemplary embodiment, the air-fuel ratio of air and fuel that flow into an engine from an inlet manifold of the engine is corrected by the sixth constant value that is pre-determined by the user if the exhaust gas temperature of exhaust gas upstream of the diesel oxidation catalyst exceeds the reference value of the expected exhaust gas temperature of exhaust gas upstream of the diesel oxidation catalyst by the third user defined constant value. In another alternate exemplary embodiment, the air-fuel ratio of air and fuel that flow into an engine from an inlet manifold of the engine is corrected by the sixth constant value that is pre-determined by the user if the stoichiometric ratio of fuel that flows through the engine exceeds the reference value of the expected stoichiometric ratio of fuel that flows through the engine by the fourth user defined constant value. In yet another alternate exemplary embodiment, the air-fuel ratio of air and fuel that flow into the engine from the inlet manifold of the engine is corrected by the sixth constant value that is pre-determined by the user if the concentration of oxides of nitrogen that are present in the exhaust gas that flows from the engine exceeds the reference value of the expected concentration of oxides of nitrogen that are present in the exhaust gas that flows from the engine by the fifth user defined constant value.

[0009] In an exemplary embodiment, if level of fuel within the fuel tank of the vehicle is above the threshold level of fuel that is pre-determined by the user, the energizing time of the solenoid coil of the fuel injector is retained at its original base value and is not corrected by a correction factor. Further, if level of fuel within the fuel tank of the vehicle is above the threshold level of fuel that is pre-determined by the user, the air-fuel ratio of exhaust gas that flows into the engine from the inlet manifold of the engine is retained at its original base value and is not corrected by the correction factor.

[0010] In an exemplary embodiment, the algorithm further comprises the steps of retaining the energizing time of the solenoid coil of the fuel injector at its original base value and retaining the air-fuel ratio of exhaust gas that flows into the engine from the inlet manifold of the engine at its original base value when the exhaust gas temperature of exhaust gas upstream of the turbine is substantially equal to the reference value of the expected exhaust gas temperature of exhaust gas upstream of the turbine, and the exhaust gas temperature of exhaust gas upstream of the diesel oxidation catalyst is substantially equal to the reference value of the expected exhaust gas temperature of exhaust gas upstream of the diesel oxidation catalyst. Further, the energizing time of the solenoid coil of the fuel injector is retained at its original base value, and the air-fuel ratio of exhaust gas that flows into the engine from the inlet manifold of the engine is retained at its original base value when the stoichiometric ratio of fuel that flows through the engine is substantially equal to the reference value of the expected stoichiometric ratio of fuel that flows through the engine. In addition, the concentration of oxides of nitrogen that are present in the exhaust gas that flows from the engine is substantially equal to the reference value of the expected concentration of oxides of nitrogen that are present in the exhaust gas that flows from the engine.

[0011] It must be understood that the embodiments explained above are only illustrative and do not limit the scope of the disclosure. Many modifications in the embodiments with regard to dimensions of various components are envisaged and form a part of this invention. The scope of the invention is only limited by the scope of the claims.
, Claims:
We Claim

1. An algorithm (100) for varying a calibration of an engine based on a density of bio-diesel that is filled in a fuel tank of a vehicle, the algorithm (100) comprising the steps of:
determining (110) whether a level of fuel within the fuel tank of the vehicle is below a threshold level of fuel that is pre-determined by a user;
determining (120) a set of boundary conditions including whether an exhaust gas recirculation system is in an off state, a throttle of the engine is fully open, the engine is in an idling mode, calibration parameters that are applied on the engine is unchanged, no other corrective functions in the engine are currently active, and a coolant temperature of coolant that flows through the engine if the level of fuel within the fuel tank of the vehicle is below a threshold level of fuel that is pre-determined by the user;
comparing (130) an exhaust gas temperature of exhaust gas upstream of a turbine with respect to a reference value of an expected exhaust gas temperature of exhaust gas upstream of the turbine;
comparing (140) an exhaust gas temperature of exhaust gas upstream of a diesel oxidation catalyst with respect to a reference value of an expected exhaust gas temperature of exhaust gas upstream of the diesel oxidation catalyst;
comparing (150) a stoichiometric ratio of fuel that flows through the engine with respect to a reference value of an expected stoichiometric ratio of fuel that flows through the engine;
comparing (160) a concentration of oxides of nitrogen that are present in the exhaust gas that flows from the engine with respect to a reference value of an expected concentration of oxides of nitrogen that are present in the exhaust gas that flows from the engine;
correcting (170) an energizing time of a solenoid coil of a fuel injector by a first constant value that is pre-determined by the user if one of the exhaust gas temperature of exhaust gas upstream of the turbine exceeds the reference value of the expected exhaust gas temperature of exhaust gas upstream of the turbine by a second user defined constant value, the exhaust gas temperature of exhaust gas upstream of the diesel oxidation catalyst exceeds the reference value of the expected exhaust gas temperature of exhaust gas upstream of the diesel oxidation catalyst by a third user defined constant value, the stoichiometric ratio of fuel that flows through the engine exceeds the reference value of the expected stoichiometric ratio of fuel that flows through the engine by a fourth user defined constant value, the concentration of oxides of nitrogen that are present in the exhaust gas that flows from the engine exceeds the reference value of the expected concentration of oxides of nitrogen that are present in the exhaust gas that flows from the engine by a fifth user defined constant value; and
correcting (180) an air-fuel ratio of air and fuel that flow into an engine from an inlet manifold of the engine by a sixth constant value that is pre-determined by the user if one of the exhaust gas temperature of exhaust gas upstream of the turbine exceeds the reference value of the expected exhaust gas temperature of exhaust gas upstream of the turbine by the second user defined constant value, the exhaust gas temperature of exhaust gas upstream of the diesel oxidation catalyst exceeds the reference value of the expected exhaust gas temperature of exhaust gas upstream of the diesel oxidation catalyst by the third user defined constant value, the stoichiometric ratio of fuel that flows through the engine exceeds the reference value of the expected stoichiometric ratio of fuel that flows through the engine by the fourth user defined constant value, the concentration of oxides of nitrogen that are present in the exhaust gas that flows from the engine exceeds the reference value of the expected concentration of oxides of nitrogen that are present in the exhaust gas that flows from the engine by the fifth user defined constant value.

2. An algorithm (100) for varying the calibration of the engine based on the density of bio-diesel that is filled in the fuel tank of the vehicle in accordance with Claim 1, wherein when the level of fuel within the fuel tank of the vehicle is above the threshold level of fuel that is pre-determined by the user, the energizing time of the solenoid coil of the fuel injector is retained at its original base value, and the air-fuel ratio of exhaust gas that flows into the engine from an inlet manifold of the engine is retained at its original base value.

3. An algorithm (100) for varying the calibration of the engine based on the density of bio-diesel that is filled in the fuel tank of the vehicle in accordance with Claim 1, wherein when the exhaust gas temperature of exhaust gas upstream of the turbine is substantially equal to the reference value of the expected exhaust gas temperature of exhaust gas upstream of the turbine, the exhaust gas temperature of exhaust gas upstream of the diesel oxidation catalyst is substantially equal to the reference value of the expected exhaust gas temperature of exhaust gas upstream of the diesel oxidation catalyst, the stoichiometric ratio of fuel that flows through the engine is substantially equal to the reference value of the expected stoichiometric ratio of fuel that flows through the engine, the concentration of oxides of nitrogen that are present in the exhaust gas that flows from the engine is substantially equal to the reference value of the expected concentration of oxides of nitrogen that are present in the exhaust gas that flows from the engine, the energizing time of the solenoid coil of the fuel injector is retained at its original base value, and the air-fuel ratio of exhaust gas that flows into the engine from an inlet manifold of the engine is retained at its original base value.