System and Method for Determining Non-Sensed Vehicle Operating Parameters

• US 20090165544A1
• Filed: 12/31/2007
• Published: 07/02/2009
• Est. Priority Date: 12/31/2007
• Status: Active Grant

• Current Assignee: Detroit Diesel Corporation (Mercedes-Benz Group AG)
• Original Assignee: Detroit Diesel Corporation (Mercedes-Benz Group AG)
• Inventors: Bolton, Brian Kenneth, Sun, Min
• Granted Patent: US 7,658,098 B2
• Time in Patent Office: Days
• US Class Current: 73/114.740
• CPC Class Codes: F02B 3/06 with compression ignition compression ignition engines using air or gas for blowing fuel into compressed air in cylinder F02B13/02
• 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 41/0072 Estimating, calculating or determining the EGR rate, amount or flow sensors in EGR systems F02M26/45
• CPC Class Codes: F02D 41/1445 the characteristics being related to the exhaust flow
• CPC Class Codes: F02D 41/18 by measuring intake air flow
• CPC Class Codes: F02M 26/05 High pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust system upstream of the turbine and reintroduced into the intake system downstream of the compressor
• CPC Class Codes: F02M 26/10 having means to increase the pressure difference between the exhaust and intake system, e.g. venturis, variable geometry turbines, check valves using pressure pulsations or throttles in the air intake or exhaust system

Abstract

A method and system is provided for determining non-sensed vehicle operating parameters of a vehicle system. The method and system further provide for determining an engine air mass flow rate using the non-sensed vehicle operating parameters. A plurality of vehicle operating set-points may be determined using the non-sensed vehicle system operating parameters and the non-sensed engine air mass flow rate. A controller may use the vehicle operating set-points in order to control emissions of the vehicle system.

Claims

1. A method for controlling emissions of a vehicle system, the method comprising:

determining a plurality of non-sensed vehicle operating parameters;

determining an engine air mass flow rate of the vehicle system using the non-sensed vehicle operating parameters; and

determining vehicle operating set-points for use in controlling emissions of the vehicle system, the vehicle operating set-points being determined using the non-sensed vehicle operating parameters and the determined engine air mass flow rate.

2. The method according to claim 1, further comprising determining at least a portion of the non-sensed vehicle operating parameters from a number of sensed vehicle operating parameters.

3. The method according to claim 1, wherein the plurality of non-sensed vehicle operating parameters includes a non-sensed air intake mass flow rate, the non-sensed air intake mass flow rate being determined using a volumetric efficiency ratio, a vehicle engine speed, a sensed intake manifold pressure, a displacement volume, and a sensed intake manifold temperature.

4. The method according to claim 3, wherein the non-sensed air intake mass flow rate is determined using the following relationship:

$M_{\mathrm{intake}}=V_{\mathrm{disp}}<br><br>\frac{{\mathrm{RPM}}_{\mathrm{engine}}*I<br><br><br><br>M<br><br><br><br>P}{120*R_{\mathrm{gas}}*I<br><br><br><br>M<br><br><br><br>T}<br><br>{\mathrm{\eta <br><br>}}_{\mathrm{vol}}$

wherein;

M_intake is the non-sensed intake mass flow rate, V_disp is a displacement volume of the vehicle system, RPM_engine is the sensed vehicle engine speed, IMP is the sensed intake manifold pressure, R_gas is a gas constant, IMT is the sensed intake manifold temperature, and η

_vol is the volumetric efficiency ratio.

5. The method according to claim 4, wherein the volumetric efficiency is determined using the following relationship:

η

_vol=α

(RPM_engine,PR_engine)η

<sub>vol—

map</sub>(RPM_engine,η

_intake)

wherein;

α

is a function determined using the vehicle engine speed and an engine pressure ratio; and

η

<sub>vol—

map</sub> is a function determined using the vehicle engine speed and an engine intake density.

6. The method according to claim 1, wherein the plurality of non-sensed vehicle operating parameters includes a non-sensed EGR mass flow rate, the non-sensed EGR mass flow rate being determined using the non-sensed turbine inlet temperature, the non-sensed turbine inlet pressure, an EGR valve discharge coefficient, and an engine pressure differential.

7. The method according to claim 6, wherein the non-sensed EGR mass flow rate is determined using the following relationship:

$\frac{M_{\mathrm{EGR}}^2*T<br><br><br><br>T<br><br><br><br>I}{T<br><br><br><br>P<br><br><br><br>I*\mathrm{Disc}<br><br><br><br>C^2}=C_1*\mathrm{\Delta <br><br>}<br><br><br><br>P+C_2$

wherein;

M_EGR is the non-sensed EGR mass flow rate, TTI is the non-sensed turbine inlet temperature, TPI is the non-sensed turbine inlet pressure, DisC is an EGR valve discharge coefficient, C₁ is a constant value dependent upon the vehicle system, C₂ is a function of a sensed vehicle engine speed and a vehicle engine load, and Δ

P is the engine pressure differential.

8. The method according to claim 1, wherein the plurality of non-sensed vehicle operating parameters includes a non-sensed turbine mass flow rate, the non-sensed turbine mass flow rate being determined using a reduced turbine mass flow rate, the non-sensed turbine inlet temperature, and the non-sensed turbine inlet pressure.

9. The method according to claim 8, wherein the non-sensed turbine mass flow rate is determined using the following relationship:

$M_{\mathrm{turbine}}=\frac{M_{\mathrm{turbine\_reduced}}*T<br><br><br><br>P<br><br><br><br>I}{\sqrt{T<br><br><br><br>T<br><br><br><br>I}}$

wherein;

M_turbine is the non-sensed turbine mass flow rate, M<sub>turbine—

reduced</sub> is the reduced turbine mass flow rate, TTI is the non-sensed turbine inlet temperature, and TPI is the non-sensed turbine inlet pressure.

10. The method according to claim 9, wherein the reduced turbine mass flow rate is determined using the following relationship:

M<sub>turbine—

reduced</sub>=f<sub>turbine—

map</sub>(S,PR_turbine)

wherein;

M<sub>turbine—

reduced</sub> is the reduced turbine mass flow rate, f<sub>turbine—

nap</sub> is a mapped turbine function, S is a VGT vane pulse width modulation value, and PR_turbine is a VGT pressure ratio.

11. The method according to claim 1, wherein the plurality of non-sensed vehicle operating parameters includes a non-sensed turbine inlet temperature, the non-sensed turbine inlet temperature being determined using a sensed intake manifold temperature, an engine exhaust energy fraction, a mass fueling rate, and the non-sensed intake mass flow rate.

12. The method according to claim 11, wherein the non-sensed turbine inlet temperature is determined using the following relationship:

$T<br><br><br><br>T<br><br><br><br>I=I<br><br><br><br>M<br><br><br><br>T+\frac{L<br><br><br><br>H<br><br><br><br>V*F_{\mathrm{exh\_energy}}*M_{\mathrm{fueling}}}{{\mathrm{Cp}}_{\mathrm{exh}}*M_{\mathrm{intake}}}$

wherein;

TTI is the non-sensed inlet turbine temperature, IMT is the sensed intake manifold temperature, LHV is a lower heat value of the fuel, F<sub>exh—

energy</sub> is the engine exhaust energy fraction, M_fueling is the mass fueling rate, Cp_exh is a specific heat of the exhaust gas, and M_intake is the non-sensed intake mass flow rate.

13. The method according to claim 1, wherein the non-sensed turbine inlet pressure is determined using the non-sensed turbine inlet temperature, a mass fueling rate, the non-sensed intake mass flow rate, the non-sensed EGR mass flow rate, and the non-sensed turbine mass flow rate.

14. The method according to claim 13, wherein the non-sensed turbine inlet pressure is determined using the following relationship:

$·<br><br>\frac{V_{\mathrm{exh\_manifold}}}{R_{\mathrm{exh\_gas}}}<br><br>\frac{<br><br>}{<br><br>t}<br><br>\left(\frac{T<br><br><br><br>P<br><br><br><br>I}{T<br><br><br><br>T<br><br><br><br>I}\right)=M_{\mathrm{fueling}}+M_{\mathrm{intake}}-M_{\mathrm{EGR}}-M_{\mathrm{turbine}}$

wherein;

V<sub>exh—

manifold</sub> is a exhaust manifold volume, R<sub>exh—

gas</sub> is an exhaust gas constant, TPI is the non-sensed turbine inlet pressure, TTI is the non-sensed turbine inlet temperature, M_Fueling is the mass fueling rate, M_intake is the non-sensed intake mass flow rate, M_EGR is the non-sensed EGR mass flow rate, and M_turbine is the non-sensed turbine mass flow rate.

15. A method for controlling emissions of a vehicle system, the method comprising:

determining a non-sensed EGR mass flow rate, a non-sensed air intake mass flow rate, a non-sensed turbine mass flow rate, a non-sensed turbine inlet temperature, and a non-sensed turbine inlet pressure using a plurality of sensed vehicle operating parameters;

determining an engine air mass flow rate of the engine using the non-sensed EGR mass flow rate, the non-sensed air intake mass flow rate, the non-sensed turbine mass flow rate, the non-sensed turbine inlet temperature, and the non-sensed turbine inlet pressure;

determining a plurality of vehicle operating set-points using the non-sensed EGR mass flow rate, the non-sensed air intake mass flow rate, the non-sensed turbine mass flow rate, the non-sensed turbine inlet temperature, the non-sensed turbine inlet pressure, and the engine air mass flow rate; and

determining future operations of the vehicle system using the determined vehicle operating set-points, wherein the determined future operations are used to modify the determined vehicle operating set-points in order to control the emissions of the vehicle system.

16. The method according to claim 15, wherein the sensed vehicle operating parameters include an intake manifold pressure, an intake manifold temperature, and a vehicle engine speed.

17. A system for use in controlling emissions of a vehicle system, the system comprising:

a plurality of hardware sensors providing a plurality of sensed vehicle operating parameters, the plurality of hardware sensors including an intake manifold pressure sensor, an intake manifold temperature sensor, and a vehicle engine speed sensor; and

a controller configured for;

determining a plurality of non-sensed vehicle operating parameters based upon the data provided from the plurality of sensed vehicle operating parameters;

determining a non-sensed engine air mass flow rate based upon the determined non-sensed vehicle operating parameters;

determining a plurality of vehicle operating set-points using the non-sensed vehicle operating parameters and the non-sensed engine air mass flow rate; and

controlling emissions of the vehicle system using the determined vehicle operating set-points.

18. The method according to claim 17, wherein the non-sensed vehicle operating parameters include a non-sensed air intake mass flow rate, the non-sensed air intake mass flow rate being determined using the following relationship:

$M_{\mathrm{intake}}=V_{\mathrm{disp}}<br><br>\frac{{\mathrm{RPM}}_{\mathrm{engine}}*I<br><br><br><br>M<br><br><br><br>P}{120*R_{\mathrm{gas}}*I<br><br><br><br>M<br><br><br><br>T}<br><br>{\mathrm{\eta <br><br>}}_{\mathrm{vol}}$

wherein;

M_intake is the non-sensed intake mass flow rate, V_disp is a displacement volume, RPM_engine is a sensed vehicle engine speed, IMP is a sensed intake manifold pressure, R_gas is a gas constant, IMT is a sensed intake manifold temperature, and η

_vol is a volumetric efficiency ratio.

19. The method according to claim 17, wherein the non-sensed vehicle operating parameters include a non-sensed EGR mass flow rate, the non-sensed EGR mass flow rate being determined using the following relationship:

$\frac{M_{\mathrm{EGR}}^2*T<br><br><br><br>T<br><br><br><br>I}{T<br><br><br><br>P<br><br><br><br>I<br><br>*\mathrm{Disc}<br><br><br><br>C^2}=C_1*\mathrm{\Delta <br><br>}<br><br><br><br>P+C_2$

wherein;

M_EGR is the non-sensed EGR mass flow rate, TTI is a non-sensed turbine inlet temperature, TPI is a non-sensed turbine inlet pressure, DisC is an EGR valve discharge coefficient, C₁ is a constant value dependent upon the vehicle system, C₂ is a function of a sensed vehicle engine speed and a vehicle engine load, and Δ

P is a engine pressure differential.

20. The method according to claim 17, wherein the non-sensed vehicle operating parameters include a non-sensed turbine mass flow rate, the non-sensed turbine mass flow rate being determined using the following relationship:

$M_{\mathrm{turbine}}=\frac{M_{\mathrm{turbine\_reduced}}*T<br><br><br><br>P<br><br><br><br>I<br><br>}{\sqrt{T<br><br><br><br>T<br><br><br><br>I}}$

wherein;

M_turbine is the non-sensed turbine mass flow rate, M<sub>turbine—

reduced</sub> is a reduced turbine mass flow rate, TTI is a non-sensed turbine inlet temperature, and TPI is a non-sensed turbine inlet pressure.