Torque control of supercharged engine
View Patent ↗An engine system includes an engine having an intake manifold and a supercharger that supplies compressed air to the intake manifold. An engine control module calculates a desired pre-supercharged pressure of air into the supercharger and calculates a desired manifold air flow into the engine. The engine control module determines a desired throttle area based on the desired pre-supercharged pressure and the desired manifold air flow and generates control signals to control the engine based on the desired throttle area.
1. An engine system, comprising:
an engine having an intake manifold;
a supercharger that supplies compressed air to said intake manifold; and
a first module that calculates a desired pre-supercharged pressure of air into said supercharger;
a second module that calculates a desired manifold air flow into said engine;
a third module that determines a desired throttle area based on said desired pre-supercharged pressure and said desired manifold air flow; and
a fourth module that generates control signals to control said engine based on said desired throttle area.
2. The engine system of claim 1 further comprising a fifth module that determines a desired manifold absolute pressure, wherein said desired pre-supercharged pressure is calculated based on said desired manifold absolute pressure.
3. The engine system of claim 1 further comprising:
a first sensor that generates a first signal based on a pre-supercharged pressure of air within said supercharger;
a second sensor that generates a second signal based on a manifold absolute pressure; and
wherein said desired pre-supercharged pressure is determined based on said first signal and said second signal.
4. The engine system of claim 1 further comprising a fifth module that calculates a desired air-per-cylinder and said desired manifold air flow is based on said desired air-per-cylinder.
5. The engine system of claim 4 further comprising a sixth module that determines an air-per-cylinder correction and corrects said desired air-per-cylinder based on said air-per-cylinder correction.
6. The engine system of claim 5 further comprising a seventh module that calculates a torque estimate and said air-per-cylinder correction is based on said torque estimate.
7. The engine system of claim 1 further comprising a bypass valve that is regulated based on a bypass schedule to control a flow of supercharged air from said supercharger lo said engine.
8. The engine system of claim 7 wherein said bypass schedule is determined based on a desired manifold absolute pressure and a desired air-per-cylinder.
9. A method of controlling a torque output of an engine having a supercharger, comprising:
calculating a desired pre-supercharged pressure of air into said supercharger;
calculating a desired manifold air flow into said engine;
determining a desired throttle area based on said desired pre-supercharged pressure and said desired manifold air flow; and
controlling said engine based on said desired throttle area.
10. The method of claim 9 further comprising determining a desired manifold absolute pressure, wherein said desired pre-supercharged pressure is calculated based on said desired manifold absolute pressure.
11. The method of claim 10 wherein said desired pre-supercharged pressure is further determined based on a pre-supercharged pressure and a manifold absolute pressure.
12. The method of claim 9 further comprising calculating a desired air-per-cylinder, wherein said desired manifold air flow is based on said desired air-per-cylinder.
13. The method of claim 12 further comprising:
determining an air-per-cylinder correction; and
correcting said desired air-per-cylinder based on said air-per-cylinder correction.
14. The method of claim 13 further comprising calculating a torque estimate, wherein said air-per-cylinder correction is based on said torque estimate.
15. The method of claim 9 further comprising:
determining a bypass schedule; and
controlling a bypass valve of said engine based on said bypass schedule to regulate a supercharged air flow into said engine.
16. The method of claim 15 wherein said bypass schedule is determined based on a desired manifold absolute pressure and a desired air-per-cylinder.
17. The method of claim 9 further comprising determining a supercharger friction factor based on a pressure differential and an engine speed, wherein said desired throttle area is further based on said friction factor.
18. A method of controlling a torque output of an engine having a supercharger, comprising:
calculating a desired pre-supercharged pressure of air into said supercharger;
calculating a desired manifold air flow into said engine;
determining a desired throttle area based on said desired pre-supercharged pressure and said desired manifold air flow;
regulating a bypass valve of said engine based on a bypass schedule to regulate a supercharged air flow into said engine; and
controlling said engine based on said desired throttle area.
19. The method of claim 18 further comprising determining a desired manifold absolute pressure, wherein said desired pre-supercharged pressure is calculated based on said desired manifold absolute pressure.
20. The method of claim 19 wherein said desired pre-supercharged pressure is further determined based on a pre-supercharged pressure and a manifold absolute pressure.
21. The method of claim 18 further comprising calculating a desired air-per-cylinder, wherein said desired manifold air flow is based on said desired air-per-cylinder.
22. The method of claim 21 further comprising:
determining an air-per-cylinder correction; and
correcting said desired air-per-cylinder based on said air-per-cylinder correction.
23. The method of claim 22 further comprising calculating a torque estimate, wherein said air-per-cylinder correction is based on said torque estimate.
24. The method of claim 18 further comprising determining said bypass schedule based on a desired manifold absolute pressure and a desired air-per-cylinder.
25. An engine system, comprising:
an engine having an intake manifold;
a supercharger that supplies compressed air to said intake manifold; and
an engine control module that calculates a desired pre-supercharged pressure of air into said supercharger, that calculates a desired manifold air flow into said engine, that determines a desired throttle area based on said desired pre-supercharged pressure and said desired manifold air flow and that generates control signals to control said engine based on said desired throttle area.
26. The engine system of claim 25 wherein said engine control module determines a desired manifold absolute pressure, wherein said desired pre-supercharged pressure is calculated based on said desired manifold absolute pressure.
27. The engine system of claim 25 further comprising:
a first sensor that generates a first signal based on a pre-supercharged pressure of air within said supercharger;
a second sensor that generates a second signal based on a manifold absolute pressure; and
wherein said desired pre-supercharged pressure is determined based on said first signal and said second signal.
28. The engine system of claim 25 wherein said engine control module calculates a desired air-per-cylinder and said desired manifold air flow is based on said desired air-per-cylinder.
29. The engine system of claim 28 wherein said engine control module determines an air-per-cylinder correction and corrects said desired air-per-cylinder based on said air-per-cylinder correction.
30. The engine system of claim 29 wherein said engine control module calculates a torque estimate and said air-per-cylinder correction is based on said torque estimate.
31. The engine system of claim 25 further comprising a bypass valve that is regulated based on a bypass schedule to control a flow of supercharged air from said supercharger to said engine.
32. The engine system of claim 31 wherein said bypass schedule is determined based on a desired manifold absolute pressure and a desired air-per-cylinder.