Prediction of intake manifold pressure in an engine system

Patent metadata

Field	Value
Publication number	US-9644543-B2
Application number	US-201514623819-A
Country	US
Kind code	B2
Filing date	Feb 17, 2015
Priority date	Feb 17, 2015
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

An engine assembly includes an intake manifold and a manifold absolute pressure sensor configured to generate a current measured manifold absolute pressure (MAP M ) signal for the intake manifold. The assembly includes a throttle valve adjustable to control airflow to the intake manifold and a throttle position sensor configured to generate a current measured throttle position (TP M ) signal. A controller is operatively connected to the throttle valve and the manifold absolute pressure sensor and has a processor and tangible, non-transitory memory on which is recorded instructions for executing a method for determining a predicted manifold absolute pressure (MAP P ). Execution of the instructions by the processor causes the controller to determine the predicted manifold absolute pressure (MAP P ) based at least partially on a predicted throttle flow (TF P ) and the current measured manifold absolute pressure (MAP M ) signal.

First claim

The invention claimed is:

1. An engine assembly comprising:
an intake manifold;
an engine operatively connected to the intake manifold;
a manifold absolute pressure sensor configured to generate a current measured manifold absolute pressure (MAP M ) signal for the intake manifold;
a throttle valve adjustable to control airflow to the intake manifold;
a throttle position sensor configured to generate a current measured throttle position (TP M ) signal for the throttle valve; and
a controller operatively connected to the throttle valve and having a processor and tangible, non-transitory memory on which is recorded instructions for executing a method for determining a predicted manifold absolute pressure (MAP P );
wherein execution of the instructions by the processor causes the controller to:
determine a predicted throttle position (TP P ) based at least partially on the current measured throttle position (TP M ) signal;
determine a predicted throttle flow (TF P ) based at least partially on the predicted throttle (TP P );
determine the predicted manifold absolute pressure (MAP P ) based at least partially on the predicted throttle flow (TF P ) and the current measured manifold absolute pressure (MAP M ) signal; and
control the engine based at least partially on the predicted manifold absolute pressure (MAP P ).

2. The assembly of claim 1 , further comprising:
an upstream temperature sensor positioned upstream of the throttle valve and configured to generate an upstream temperature (T U ) signal; and
an upstream pressure sensor positioned upstream of the throttle valve and configured to provide an upstream pressure (P U ) signal.

3. The assembly of claim 1 :
wherein the controller is configured to generate a current commanded throttle position (TP C ) signal; and
said determining the predicted throttle position (TP P ) includes calculating the predicted throttle position (TP P ) as a function of the current measured throttle position (TP M ) signal and the current commanded throttle position (TP C ) signal.

4. The assembly of claim 1 , wherein said determining the predicted throttle flow (TF P ) includes:
determining a throttle area (A T ) at the predicted throttle position (TP P ); and
calculating a condition factor (F 1 ) as a function of the upstream temperature (T U ) signal, current measured manifold absolute pressure (MAP M ) signal, and upstream pressure (P U ) signal.

5. The assembly of claim 4 , wherein said throttle area (A T ) is obtained as: A T =A max (1−cosine(TP P )), such that A max is a predefined maximum throttle area and wherein the predicted throttle position (TP P ) is expressed as an angle between 0 and 90°.

6. The assembly of claim 4 , wherein the condition factor (F 1 ) is defined as: F 1 =P U *ψ/√{square root over (RTu)}; and wherein ψ=Square root of {2k*((MAP M /P U ) 2/k −(MAP M /P U )(k+1)/k) /(k−1)}, such that k is a predefined constant.

7. The assembly of claim 4 , wherein said determining the predicted throttle flow (TF P ) further includes:
selecting a flow calibration factor (L 1 ) at the predicted throttle position (TP P ) signal from a first look-up table; and
calculating the predicted throttle flow (TF P ) as a product of the first calibration factor (L 1 ), the throttle area (A T ) and condition factor (F 1 ) such that: TF P =L 1 *A T *F 1 .

8. The assembly of claim 1 , further comprising:
a camshaft assembly operatively connected to the engine;
an engine speed sensor operatively connected to the engine and configured to generate an RPM signal; and
a camshaft position sensor operatively connected to the camshaft assembly and configured to generate current measured camshaft position (CP M ) signal.

9. The assembly of claim 8 , further comprising:
a manifold temperature sensor operatively connected to the intake manifold and configured to generate manifold temperature (T M ) signal, the intake manifold defining a manifold volume (V M );
wherein the engine includes a number of cylinders (n cyl ), such that each of the number of cylinders defines a cylinder volume (V cyl ) and the number of cylinders (n cyl ) is at least one;
wherein the engine defines a sampling time (t s ) based at least partially on the RPM signal and the number of cylinders (n cyl ) such that: t s =120/(RPM*n cyl ).

10. The assembly of claim 9 :
wherein the controller is configured to select a second calibration factor (L 2 ) from a second look-up table based at least partially on the current measured manifold absolute pressure (MAP M ) signal, the RPM signal and the current measured cam position (CP M ) signal; and
wherein the controller is configured to determine a current air flow per cylinder (APC C ) as a function of the second calibration factor (L 2 ), the current measured manifold absolute pressure (MAP M ) signal, the cylinder volume (V cyl ) and the manifold temperature (T M ) signal.

11. The assembly of claim 10 , wherein the current air flow per cylinder (APC C ) is defined as: APC C =(L 2 *MAP M *V cyl )/(R*T M ), where R is a predefined gas constant.

12. The assembly of claim 10 , wherein said determining the predicted manifold absolute pressure (MAP P ) includes calculating the predicted manifold absolute pressure (MAP P ) at least partially as a function of the current air flow per cylinder (APC C ), current measured manifold absolute pressure (MAP M ) signal, the predicted throttle flow (TF P ), the manifold temperature (T M ) signal and the sampling time (t s ).

13. The assembly of claim 10 , wherein the predicted manifold absolute pressure (MAP P ) is defined as: MAP P =MAP M +(TF P *t s −APC C ) R*T M /V M , where R is a predefined gas constant.

14. The assembly of claim 10 , wherein the controller is configured to determine a predicted air flow per cylinder (APC P ) at least partially as a function of the predicted future manifold absolute pressure (MAP P ), a third calibration factor (L 3 ), the cylinder volume (V cyl ) and the manifold temperature (T M ) signal.

15. The assembly of claim 14 , wherein the predicted air flow per cylinder (APC P ) is defined as: APC P =(MAP P *L 3 *V cyl )/(R*T M ).

16. A vehicle comprising:
an intake manifold;
an engine operatively connected to the intake manifold;
a manifold absolute pressure sensor configured to generate a current measured manifold absolute pressure (MAP M ) signal for the intake manifold;
a throttle valve adjustable to control airflow to the intake manifold;
a throttle position sensor configured to generate a current measured throttle position (TP M ) signal for the throttle valve;
a controller operatively connected to the throttle valve and having a processor and tangible, non-transitory memory on which is recorded instructions for executing a method for determining a predicted manifold absolute pressure (MAP P );
wherein execution of the instructions by the processor causes the controller to:
determine a predicted throttle position (TP P ) based at least partially on the current measured throttle position (TP M ) signal;
determine a predicted throttle flow (TF P ) based at least partially on the predicted throttle position (TP P );
determine the predicted manifold absolute pressure (MAP P ) based at least partially on the predicted throttle flow (TF P ) and the current measured manifold absolute pressure (MAP M ) signal;
control the engine based at least partially on the predicted manifold absolute pressure (MAP P ); and

wherein said determining the predicted manifold absolute pressure (MAP P ) includes calculating the predicted manifold absolute pressure (MAP P

Assignees

• Gm Global Tech Operations Llc

Inventors

• Hu Yiran
• Haskara Ibrahim
• Li Shifang
• Rajagopalan Sai S V
• Muldoon Steven E
• Chang Chen-Fang

Classifications

• F02D2200/0406

  Intake manifold pressure · CPC title

• F02D41/10

  for acceleration · CPC title

• F02D41/0002

  Controlling intake air · CPC title

• F02D2200/0408

  Estimation of intake manifold pressure · CPC title

• F02D2009/0225

  Intake air or mixture temperature · CPC title