초록 ▼

A control system for an internal combustion engine having at least one fuel injection valve for injecting fuel to an intake pipe or a combustion chamber of the engine. Intake gas state parameters indicative of a state of the intake gases supplied to the engine are detected. Demand values of the inta

A control system for an internal combustion engine having at least one fuel injection valve for injecting fuel to an intake pipe or a combustion chamber of the engine. Intake gas state parameters indicative of a state of the intake gases supplied to the engine are detected. Demand values of the intake gas state parameters are calculated according to operating condition parameters indicative of an operating condition of the engine. The intake gas state is controlled so that the intake gas state parameters coincide with the demand values. A control value is then calculated according to the operating condition parameters and deviations of the intake gas state parameters from the demand values. Accordingly, an amount of fuel injected by the at least one fuel injection valve is controlled according to the control value.

대표청구항 ▼

What is claimed is: 1. A control system for an internal combustion engine having fuel injection means for injecting fuel to an intake pipe or a combustion chamber of said engine, comprising: intake gas state parameter detecting means for detecting intake gas state parameters indicative of a state o

What is claimed is: 1. A control system for an internal combustion engine having fuel injection means for injecting fuel to an intake pipe or a combustion chamber of said engine, comprising: intake gas state parameter detecting means for detecting intake gas state parameters indicative of a state of intake gases supplied to said engine; demand value calculating means for calculating demand values of the intake gas state parameters according to operating condition parameters indicative of an operating condition of said engine; intake gas state control means for controlling the intake gas state so that the intake gas state parameters coincide with the demand values; and fuel injection control means for calculating a control value according to the operating condition parameters and deviations of the intake gas state parameters from the demand values, and for controlling an amount of fuel injected by said fuel injection means according to the control value. 2. The control system according to claim 1, wherein said fuel injection control means controls a fuel injection timing of said fuel injection means according to the operating condition parameters and the deviations of the intake gas state parameters from the demand values. 3. The control system according to claim 1, wherein said fuel injection control means comprises: basic control value calculating means for calculating a basic control value according to the operating condition parameters; change rate parameter calculating means for calculating change rate parameters indicative of change rates of the basic control value according to the operating condition parameters; correction value calculating means for calculating correction values by multiplying the change rate parameters by the deviations of the intake gas state parameters from the demand values; and control value calculating means for calculating the control value of the fuel injection amount by correcting the basic control value with the correction values, wherein said fuel injection control means performs the fuel injection control according to the control value calculated by said control value calculating means. 4. The control system for an internal combustion engine according to claim 1, wherein the intake gas state parameters are any two of an intake pressure, an intake oxygen partial pressure, and an intake inert gas partial pressure. 5. The control system according to claim 1, wherein said engine comprises an exhaust gas recirculation mechanism for recirculating exhaust gases to said intake pipe, and the intake gas state parameters are any two of an intake pressure, an intake fresh air flow rate, and a flow rate of recirculated exhaust gases. 6. The control system according to claim 4, wherein an intake gas temperature is further included in the intake gas state parameters, wherein said control system further comprises intake gas temperature reference value calculating means for calculating a reference value of the intake gas temperature, and wherein said fuel injection control means performs the fuel injection control according to a deviation of a detected intake gas temperature from the reference value. 7. The control system according to claim 1, further comprising combustion mode determining means for determining a combustion mode of said engine according to the operating condition parameters, wherein said fuel injection control means calculates the control value using a control map set corresponding to the combustion mode. 8. The control system according to claim 7, wherein when said combustion mode determining means changes the combustion mode, said fuel injection control means uses the control map corresponding to the combustion mode before the combustion mode is changed if at least one of absolute values of the deviations is equal to or greater than a predetermined threshold value, and said fuel injection control means uses the control map corresponding to the changed combustion mode if each of the absolute values of the deviations is less than the predetermined threshold value. 9. The control system according to claim 1, wherein said engine has a throttle valve disposed in said intake pipe, an exhaust gas recirculation mechanism for recirculating exhaust gases to said intake pipe, and a turbo charger having a compressor wheel and a turbine wheel, said exhaust gas recirculation mechanism including an exhaust gas recirculation passage and an exhaust gas recirculation control valve in said exhaust gas recirculation passage, said turbo charger including movable vanes for changing a flow rate of exhaust gases injected to said turbine wheel, wherein said intake gas state control means controls the intake gas state by changing openings of said throttle valve, exhaust gas recirculation control valve, and movable vanes. 10. The control system according to claim 9, wherein said intake gas state control means controls the intake gas state using a model predictive control. 11. The control system according to claim 10, wherein a controlled object model used in the model predictive control is defined using, as control inputs, a mass flow rate of gases passing through said movable vanes, a mass flow rate of gases passing through said exhaust gas recirculation control valve, and a mass flow rate of fresh air passing through said throttle valve. 12. A control method for an internal combustion engine having at least one fuel injection valve for injecting fuel to an intake pipe or a combustion chamber of said engine, said control method comprising the steps of: a) detecting intake gas state parameters indicative of a state of intake gases supplied to said engine; b) calculating demand values of the intake gas state parameters according to operating condition parameters indicative of an operating condition of said engine; c) controlling the intake gas state so that the intake gas state parameters coincide with the demand values; d) calculating a control value according to the operating condition parameters and deviations of the intake gas state parameters from the demand values; and e) controlling an amount of fuel injected by said at least one fuel injection valve according to the control value. 13. The control method according to claim 12, wherein a fuel injection timing of said at least one fuel injection valve is controlled according to the operating condition parameters and the deviations of the intake gas state parameters from the demand values. 14. The control method according to claim 12, wherein said step d) includes the steps of: i) calculating a basic control value according to the operating condition parameters; ii) calculating change rate parameters indicative of change rates of the basic control value according to the operating condition parameters; iii) calculating correction values by multiplying the change rate parameters by the deviations of the intake gas state parameters from the demand values; and iv) calculating a control value of the fuel injection amount by correcting the basic control value with the correction values, wherein the fuel injection control is performed according to the calculated control value. 15. The control method according to claim 12, wherein the intake gas state parameters are any two of an intake pressure, an intake oxygen partial pressure, and an intake inert gas partial pressure. 16. The control method according to claim 12, wherein said engine comprises an exhaust gas recirculation mechanism for recirculating exhaust gases to said intake pipe, and the intake gas state parameters are any two of an intake pressure, an intake fresh air flow rate, and a flow rate of recirculated exhaust gases. 17. The control method according to claim 15, wherein an intake gas temperature is further included in the intake gas state parameters, wherein said control method further includes the step of calculating a reference value of the intake gas temperature, and wherein the fuel injection control is performed according to a deviation of a detected intake gas temperature from the reference value. 18. The control method according to claim 12, further comprising the step of determining a combustion mode of said engine according to the operating condition parameters, wherein the control value is calculated using a control map set corresponding to the combustion mode. 19. The control method according to claim 18, wherein when the combustion mode is changed, the control map corresponding to the combustion mode before the combustion mode is changed is used if at least one of absolute values of the deviations is equal to or greater than a predetermined threshold value, and the control map corresponding to the changed combustion mode is used if each of the absolute values of the deviations is less than the predetermined threshold value. 20. The control method according to claim 12, wherein said engine has a throttle valve disposed in said intake pipe, an exhaust gas recirculation mechanism for recirculating exhaust gases to said intake pipe, and a turbo charger having a compressor wheel and a turbine wheel, said exhaust gas recirculation mechanism including an exhaust gas recirculation passage and an exhaust gas recirculation control valve in said exhaust gas recirculation passage, said turbo charger including movable vanes for changing a flow rate of exhaust gases injected to said turbine wheel, wherein the intake gas state is controlled by changing openings of said throttle valve, exhaust gas recirculation control valve, and movable vanes. 21. The control method according to claim 20, wherein the intake gas state is controlled using a model predictive control. 22. The control method according to claim 21, wherein a controlled object model used in the model predictive control is defined using, as control inputs, a mass flow rate of gases passing through said movable vanes, a mass flow rate of gases passing through said exhaust gas recirculation control valve, and a mass flow rate of fresh air passing through said throttle valve.