Method of estimating the boost capability of a turbocharged internal combustion engine

Patent metadata

Field	Value
Publication number	US-9951698-B2
Application number	US-201414514170-A
Country	US
Kind code	B2
Filing date	Oct 14, 2014
Priority date	Oct 14, 2013
Publication date	Apr 24, 2018
Grant date	Apr 24, 2018

Abstract

A method of estimating a boost pressure of a turbocharger is disclosed. A throttle body temperature is estimated as a function of engine operating parameters. An intake air mass flow and an exhaust mass flow are estimated as a function of the throttle body temperature. A turbine inlet pressure and a turbine outlet pressure are estimated as a function of engine operating parameters. A turbine speed is estimated as a function of the intake air mass flow, exhaust mass flow and turbine inlet and outlet pressure. The boost pressure is estimated as a function of the turbine speed. Estimation of the maximum boost pressure of a turbocharged internal combustion engine is performed method cyclically as follows: estimating a throttle temperature, estimating an air mass flow and an exhaust mass flow, estimating a turbine inlet pressure and a turbine outlet pressure, estimating a turbine speed, and estimating the maximum boost pressure.

First claim

The invention claimed is:

1. A method of controlling a boost pressure of a turbocharger for an internal combustion engine comprising:
estimating a throttle body temperature as a function of at least one engine operating parameter, the at least one engine operating parameter including a predicted engine speed calculated as follows:
n i+1 =n i +( n i −n i−1 )/( t i −t i−1 )

where: n=engine speed, t=time, and i=cycle number;
estimating an intake air mass flow and an exhaust mass flow as a function of said throttle body temperature;
estimating a turbine inlet pressure and a turbine outlet pressure as a function of at least one engine operating parameter;
estimating a turbine speed as a function of said intake air mass flow, exhaust mass flow and turbine inlet and outlet pressure;
estimating a boost pressure as a function of said turbine speed; and
generating a control signal based on said estimated boost pressure to control the turbocharger; and
controlling the turbocharger using the control signal to adjust the boost pressure for generating the estimated boost pressure.

2. The method according to claim 1 , wherein the method is performed cyclically.

3. The method according to claim 2 , wherein the method is performed exactly four times.

4. The method according to claim 1 , wherein the at least one engine operating parameter includes a cooling capacity factor estimated as a function of at least one engine operating parameter selected from the group consisting of a current boost pressure, a current turbocharger inlet pressure, a current compressor inlet temperature and a current inlet manifold temperature.

5. The method according to claim 4 , wherein the at least one engine operating parameter includes the cooling capacity factor estimated as a function of a current boost pressure, a current turbocharger inlet pressure, a current compressor inlet temperature and a current inlet manifold temperature.

6. The method according to claim 1 , wherein said throttle body temperature is estimated as a function of a current boost pressure, a current turbocharger inlet pressure, a current compressor inlet temperature and a cooling capacity factor.

7. The method according to claim 1 , wherein said air mass flow and exhaust mass flow are estimated as a function of the predicted engine speed, a current boost pressure, a volumetric efficiency, an intake actuator state, a current ambient air pressure and the estimated throttle body temperature.

8. The method according to claim 1 , wherein said turbine inlet pressure and said turbine outlet pressure are estimated as a function of the intake air mass flow and the exhaust mass flow.

9. The method according to claim 1 , wherein said turbine speed is estimated as a function of the exhaust mass flow, the turbine inlet pressure, the turbine outlet pressure and a current turbine inlet temperature.

10. The method according to claim 1 , wherein said boost pressure is estimated as a function of the air mass flow, the current turbine inlet temperature, the current turbocharger inlet pressure and the turbine speed.

11. An internal combustion engine comprising a turbocharger wherein a maximum boost pressure of the turbocharger is estimated by the method according to claim 1 .

12. A non-transitory computer program comprising a computer-code operable with a processor for performing the method according to claim 1 .

13. A computer program product on which the non-transitory computer program according to claim 12 is stored.

14. A method of controlling a boost pressure of a turbocharger for an internal combustion engine comprising:
estimating a throttle body temperature, in a processor, as a function of a current boost pressure, a current turbocharger inlet pressure, a current compressor inlet temperature and a cooling capacity factor;
estimating an intake air mass flow and an exhaust mass flow, in the processor, as a function of said throttle body temperature;
estimating a turbine inlet pressure and a turbine outlet pressure, in the processor, as a function of at least one engine operating parameter;
estimating a turbine speed, in the processor, as a function of said intake air mass flow, exhaust mass flow and turbine inlet and outlet pressure;
estimating a boost pressure, in the processor, as a function of said turbine speed;
generating a control signal based on said estimated boost pressure, in the processor, to control the turbocharger; and
controlling the turbocharger using the control signal to adjust the boost pressure for generating the estimated boost pressure.

15. A control apparatus for an internal combustion engine comprising an electronic control unit and a computer program product stored in non-transitory computer readable medium having a computer-code operable with the electronic control unit to execute the following steps:
estimate a throttle body temperature as a function of at least one engine operating parameter;
estimate an intake air mass flow and an exhaust mass flow as a function of said throttle body temperature, a predicted engine speed, a current boost pressure, a volumetric efficiency, an intake actuator state, a current ambient air pressure and the estimated throttle body temperature;
estimate a turbine inlet pressure and a turbine outlet pressure as a function of at least one engine operating parameter;
estimate a turbine speed as a function of said intake air mass flow, exhaust mass flow and turbine inlet and outlet pressure;
estimate a boost pressure as a function of said turbine speed;
generate a control signal based on said estimated boost pressure to control the turbocharger; and
control the turbocharger using the control signal to adjust the boost pressure for generating the estimated boost pressure.

16. The control apparatus of claim 15 , wherein the at least one engine operating parameter is a predicted engine speed calculated as follows:
n i+1 =n i +( n i −n i−1 )/( t i −t i−1 )
where: n=engine speed, t=time, and i=cycle number.

17. The control apparatus of claim 15 , wherein said throttle body temperature is estimated as a function of a current boost pressure, a current turbocharger inlet pressure, a current compressor inlet temperature and a cooling capacity factor.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Suchy Martin
• Bernards Joerg
• Klein Alexander

Classifications

• F02D2200/0408

  Estimation of intake manifold pressure · CPC title

• F02D41/1446

  the characteristics being exhaust temperatures · CPC title

• F02D2200/0402

  the parameter being determined by using a model of the engine intake or its components · CPC title

• F02D2041/1433

  using a model or simulation of the system · CPC title

• F02D41/0007 Primary

  for control of turbo-charged or super-charged engines (control of the pumps per se F02B37/12) · CPC title