Inferential sensor

• US 10,309,287 B2
• Filed: 10/12/2017
• Issued: 06/04/2019
• Est. Priority Date: 11/29/2016
• Status: Active Grant

• Current Assignee: Garrett Transportation I Inc. (Garrett Motion, Inc.)
• Original Assignee: Garrett Transportation I Inc. (Garrett Motion, Inc.)
• Inventors: Pachner, Daniel, Uchanski, Michael, Lansky, Lucas
• Primary Examiner(s): Gimie, Mahmoud
• Application Number:
  US15/782,669
• Publication Number:
  US 20180149064A1
• Time in Patent Office: 600 Days
• Field of Search: 12356821
• CPC Class Codes: F01N 11/005 the temperature or pressure being estimated, e.g. by means of a theoretical model
• CPC Class Codes: F01N 11/007 the diagnostic devices measuring oxygen or air concentration downstream of the exhaust apparatus
• CPC Class Codes: F01N 2560/026 for measuring or detecting NOx
• CPC Class Codes: F01N 2900/14 said parameters being related to the exhaust gas
• CPC Class Codes: F01N 3/208 Control of selective catalytic reduction [SCR], e.g. dosing of reducing agent
• CPC Class Codes: F01N 9/005 using models instead of sensors to determine operating characteristics of exhaust systems, e.g. calculating catalyst temperature instead of measuring it directly
• CPC Class Codes: F02D 2200/0402 the parameter being determined by using a model of the engine intake or its components
• CPC Class Codes: F02D 2200/0406 Intake manifold pressure
• CPC Class Codes: F02D 2200/0411 Volumetric efficiency
• CPC Class Codes: F02D 2200/0414 Air temperature
• CPC Class Codes: F02D 2200/0418 Air humidity
• CPC Class Codes: F02D 41/0072 Estimating, calculating or determining the EGR rate, amount or flow sensors in EGR systems F02M26/45
• CPC Class Codes: F02D 41/1456 with sensor output signal being linear or quasi-linear with the concentration of oxygen
• CPC Class Codes: F02D 41/1458 with determination means using an estimation
• CPC Class Codes: F02D 41/2451 characterised by what is learned or calibrated
• CPC Class Codes: F02D 41/2454 Learning of the air-fuel ratio control
• CPC Class Codes: F02M 35/1038 for temperature or pressure
• CPC Class Codes: G01N 33/0037 for NOx
• CPC Class Codes: Y02A 50/20 Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A system and an approach for determining various pressures or flows in an internal combustion engine, such as a pressure adjacent a recirculation exhaust gas flow through a controlled valve of an engine. Also, among the sensors accommodated in the system, is a pressure sensor sensing a pressure in an intake manifold of the engine.

Claims

1. An inferential exhaust manifold pressure detection device comprising:

an exhaust gas recirculation (EGR) valve having a first fluid input, a fluid output and a second fluid input;

an exhaust manifold of an engine having a fluid output connected to the first fluid input of the EGR valve and to a fluid input of a turbine, and having a fluid input connected to exhaust ports of cylinders of the engine;

an intake manifold of the engine having a fluid input connected to the fluid output of the EGR valve and to a fluid output of a compressor, and a fluid output connected to intake ports of the cylinders;

a pressure sensor situated in the intake manifold; and

a processor having an electrical signal input connected to the pressure sensor and an electrical signal output; and

wherein;

the processor calculates an inlet pressure of the EGR valve based on a pressure from the pressure sensor;

the processor derives the calculated EGR valve inlet pressure using a turbine power versus compressor power balance in view of an efficiency of the turbine and an efficiency of the compressor; and

the processor determines a control signal for the EGR valve based on the calculated inlet pressure of the EGR and outputs the control signal to the EGR valve.

2. The device of claim 1, wherein the processor:

determines the compressor power balance based on a turbocharger angular velocity signal from a physical turbo speed sensor; and

derives a power of a turbocharger acceleration from a time derivative of the turbocharger angular velocity signal.

3. The device of claim 1, wherein the processor calculates the inlet pressure of the EGR valve as an interval of possible values based on intervals of turbocharger efficiency.

4. The device of claim 3, wherein the intervals of turbocharger efficiency are a product of a compressor efficiency and a turbine efficiency and the processor determines a maximum value of the product by finding a maximum value in the turbocharger map.

5. The device of claim 1, wherein the processor calculates a lower bound for the inlet pressure of the EGR valve based on a maximum possible turbocharger efficiency.

6. The device of claim 5, wherein the processor uses the lower bound for the inlet pressure of the EGR valve to calculate an interval containing a fresh air mass flow rate and an interval containing an EGR mass flow rate.

7. The device of claim 1, wherein the processor detects an EGR valve blockage based on an upper bound for an EGR mass flow rate when determining that the EGR mass flow rate is not sufficient for a given valve opening angle.

8. The device of claim 1, wherein the processor detects an intake system air leakage based on a lower bound on a fresh mass flow rate when determining the fresh mass flow rate.

9. The device of claim 1, wherein the processor detects one or both of an EGR valve failure and an intake air leakage failure when a turbocharger efficiency is in an Efficiency Island.

10. The device of claim 9, wherein the processor is blocked from detecting an EGR valve failure and an intake air leakage failure when the turbocharger efficiency is outside of the Efficiency Island.

11. An inferential mechanism for determining pressure in an exhaust manifold an engine having a turbocharger comprising:

an exhaust manifold having a first fluid input connected to an exhaust of an engine and having a fluid output;

an exhaust gas recirculation (EGR) valve having a first fluid input connected to the fluid output of the exhaust manifold and having a fluid output;

an intake manifold of the engine having a fluid input connected to the fluid output of the EGR valve and having a fluid output;

a pressure sensor situated in the intake manifold; and

a processor having an electrical signal input connected to the pressure sensor and having an electrical signal output; and

wherein the processor;

calculates a lower bound for an inlet pressure of the EGR valve based on a maximum possible turbocharger efficiency;

uses the lower bound for the inlet pressure of the EGR valve to calculate an interval containing a fresh air mass flow rate;

detects a fuel injection offset using the interval on a fresh air mass flow rate; and

determines a control signal to adjust fuel injection in view of the fuel injection offset and outputs the control signal to a fuel injector.

12. The mechanism of claim 11, further comprising:

a lambda sensor having an electrical signal output connected to the electrical signal input of the processor; and

wherein the processor detects the fuel injection offset using the interval on a fresh air mass flow rate by comparing the interval on a fresh air mass flow rate with an interval on a fresh air mass flow rate derived from a lambda sensor.

13. The mechanism of claim 11, further comprising:

a fresh air mass flow rate physical sensor having an electrical signal output connected to the electrical signal input of the processor; and

wherein the processor detects a fresh air mass flow rate physical sensor offset by comparing the interval on a fresh air mass flow rate sensed with a fresh air mass flow rate physical sensor.

14. The mechanism of claim 11, wherein the processor:

calculates an inlet pressure of the EGR valve based on a pressure from the pressure sensor; and

determines a control signal for the EGR valve based on the calculated inlet pressure of the EGR and outputs the control signal to the EGR valve.

15. The mechanism of claim 14, wherein the processor:

derives the calculated EGR valve inlet pressure using a turbine versus compressor power balance in view of an efficiency of a turbine connected to the output of the exhaust manifold and an efficiency of a compressor connected to the input of the intake manifold;

determines a compressor power balance based on a turbocharger angular velocity signal from a physical turbo speed sensor; and

derives a power of a turbocharger acceleration from a time derivative of the turbocharger angular velocity signal.

16. The mechanism of claim 14, wherein the processor calculates the inlet pressure of the EGR valve as an interval of possible values based on intervals of turbocharger efficiency.

17. The mechanism of claim 14, wherein the processor detects an EGR valve blockage based on an upper bound on an EGR mass flow rate when determining that the EGR mass flow rate is not sufficient for a given valve opening angle.

18. A method for inferring a pressure at an exhaust manifold of an engine having a turbocharger, the method comprising:

detecting a pressure in an intake manifold connected to an engine;

calculating an inlet pressure of an exhaust manifold connected to the engine based on the detected pressure in the intake manifold and a turbine power versus compressor power balance;

determining a control signal for an exhaust gas recirculation (EGR) valve based on the calculated inlet pressure in the exhaust manifold;

outputting the control signal for the EGR valve to the EGR valve; and

wherein the inlet pressure of the exhaust manifold is calculated as an interval of possible values based on intervals of turbocharger efficiency.