Prediction of intake manifold pressure in an engine system

Patent metadata

Field	Value
Publication number	US-2016237941-A1
Application number	US-201514623819-A
Country	US
Kind code	A1
Filing date	Feb 17, 2015
Priority date	Feb 17, 2015
Publication date	Aug 18, 2016
Grant date	—

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

1 . An engine assembly comprising:
an 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 ); and wherein 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.

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:
determine a predicted throttle position (TP P ) based at least partially on the current measured throttle position (TP M ) signal; and determine the predicted throttle flow (TF P ) based at least partially on the predicted throttle position (TP P ).

4 . The assembly of claim 3 :
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.

5 . The assembly of claim 3 , 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.

6 . The assembly of claim 5 , 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°.

7 . The assembly of claim 5 , 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.

8 . The assembly of claim 5 , 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 .

9 . The assembly of claim 1 , further comprising:
an engine operatively connected to the intake manifold; 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.

10 . The assembly of claim 9 , 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 );

11 . The assembly of claim 10 :
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.

12 . The assembly of claim 11 , 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.

13 . The assembly of claim 11 , 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 ).

14 . The assembly of claim 11 , 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.

15 . The assembly of claim 11 , 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.

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

17 . A vehicle comprising:
an 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 ); and 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 ); and
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.

18 . The vehicle of claim 17 , 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 a current air flow per cylinder (APC C ), th

Assignees

• Gm Global Tech Operations Llc

Inventors

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

Classifications

• F02D41/0002

  Controlling intake air · CPC title

• F02D2009/0228

  Manifold pressure · CPC title

• F02D2009/0225

  Intake air or mixture temperature · CPC title

• F02D2200/0408

  Estimation of intake manifold pressure · CPC title

• F02D2200/0406

  Intake manifold pressure · CPC title