System and method for estimating and controlling cylinder air charge in a direct injection internal combustion engine

• US 6,805,095 B2
• Filed: 11/05/2002
• Issued: 10/19/2004
• Est. Priority Date: 11/05/2002
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Sun, Jing, Kolmanovsky, Ilya V.
• Primary Examiner(s): HUYNH, HAI H
• Application Number:
  US10/287,982
• Publication Number:
  US 20040084015A1
• Time in Patent Office: 714 Days
• Field of Search: 123/399, 123/568.21, 123/568.22, 731/182, 701/103, 701/115
• US Class Current: 123/399
• CPC Class Codes: F01N 3/0814 combined with catalytic converters, e.g. NOx absorption/storage reduction catalysts
• CPC Class Codes: F02B 2075/125 Direct injection in the combustion chamber for spark ignition engines, i.e. not in pre-combustion chamber
• CPC Class Codes: F02D 2041/1416 Observer
• CPC Class Codes: F02D 2041/1419 the control loops being cascaded, i.e. being placed in series or nested
• 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 35/0007 using electrical feedback F02D35/0015 takes precedence
• CPC Class Codes: F02D 41/0002 Controlling intake air
• 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 41/18 by measuring intake air flow
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A method for controlling cylinder charge in a direct-injection, spark-ignition engine. The engine includes an intake manifold and an electronically controlled throttle (ETC) valve controlling air flow from the atmosphere to the intake manifold of said engine. The method includes: measuring an intake manifold pressure value, P_i,; measuring a flow value, W_thr,m, which is indicative of flow through the ETC throttle; determining a desired intake manifold pressure value, P_{i d}; determining a desired ETC valve position, u_thr,d; determining a desired flow, W_{thr d}, through the ETC valve; and, adjusting said ETC valve position, u_thr, in accordance with: said desired ETC valve position, u_thr,d; a difference between the measured intake manifold pressure value, P_i, and the determined desired intake manifold pressure value, P_{i d}; and a difference between the measured flow value, W_thr,m, through the ETC valve and the determined desired flow, W_{thr d}. In-cylinder and throttle body adaptation is also provided.

Claims

1. A method is provided for controlling cylinder charge in a direct-injection, spark-ignition engine, such engine having an intake manifold and an electronically controlled throttle (ETC) valve controlling air flow from the atmosphere to the intake manifold of said engine, such method comprising:

(A) measuring an intake manifold pressure value, P_i,;

(B) measuring a flow value, W_thr,m, indicative of flow through the ETC valve;

(C) determining a desired intake manifold pressure value, P_i.d;

(D) determining a desired flow, W_thr,d, through the ETC valve;

(E) determining a desired ETC valve position, u_thr,d; and

,

(F) adjusting said ETC valve position, u_thr, in accordance with;

(i) said desired ETC valve position, U_thr,d;

(ii) a difference between the measured intake manifold pressure value, P_i, and the determined desired intake manifold pressure value, P_i,d; and

(iii) a difference between the measured flow value, W_thr,m, through the ETC valve and the determined desired flow, W_thr.d.

2. A method for controlling cylinder charge in a direct-injection, spark-ignition engine, such engine including an intake manifold and an electronically controlled throttle (ETC) valve for controlling air flow from the atmosphere to the intake manifold of said engine, such method comprising:

parameterizing air flow through the ETC valve as;

3. The method recited in claim 2 wherein the nominal predicted flow is determined from the standard orifice flow equation.

4. The method recited in claim 2 wherein the estimator parameters are modified in accordance with:

${\widehat{\mathrm{\beta <br><br>}}}_{\mathrm{thr}}^0<br><br>\left(t+T_{\mathrm{\alpha <br><br>}}\right)={\widehat{\mathrm{\beta <br><br>}}}_{\mathrm{thr}}^0<br><br>\left(t\right)+{\mathrm{\gamma <br><br>}}_{\mathrm{thr}}^0<br><br>{\mathrm{\varepsilon <br><br>}}_{\mathrm{thr}}<br><br>\frac{1}{1+{\stackrel{\_}{W}}_{\mathrm{thr}}^2}$${\widehat{\mathrm{\beta <br><br>}}}_{\mathrm{thr}}^1<br><br>\left(t+T_{\mathrm{\alpha <br><br>}}\right)={\widehat{\mathrm{\beta <br><br>}}}_{\mathrm{thr}}^1<br><br>\left(t\right)+{\mathrm{\gamma <br><br>}}_{\mathrm{thr}}^1<br><br>{\mathrm{\varepsilon <br><br>}}_{\mathrm{thr}}<br><br>\frac{{\stackrel{\_}{W}}_{\mathrm{thr}}}{1+{\stackrel{\_}{W}}_{\mathrm{thr}}^2}$

where;

5. The method recited in claim 4 wherein the nominal predicted flow is determined from the standard orifice flow equation.

6. The method recited in claim 2 wherein the prediction is disabled when the intake manifold pressure is relatively high and the ETC valve is experiencing a relatively large transient condition.

7. The method recited in claim 4 wherein a dead zone is applied to ε

_thr before it is used.

8. The method recited in claim 4 wherein the adaptation gains are reduced at high intake manifold pressures.

9. A method for controlling air charge in a direct-injection, spark-ignition engine, such engine having an exhaust gas recirculation (EGR) valve connecting the exhaust manifold and intake manifold of the engine and an electronically controlled throttle (ETC) valve controlling air flow from the atmosphere to the intake manifold of said engine, such method comprising:

(A) providing an estimator for estimating flow through the EGR valve;

(B) during a calibration mode;

(i) applying a step function to the estimator, such estimator having a dynamic response characteristic to the applied step function, such dynamic response characteristic being a function of a parameter in such estimator;

(ii) comparing the dynamic response characteristic of the estimator to the step function to the dynamic response characteristic provided in accordance with the orifice equation applied to the intake throttle and the EGR valve; and

(iii) adjusting the parameter of the estimator to a value where the dynamic response characteristic provided by the estimator to the dynamic response characteristic provided by the estimator are substantially match to a predetermined response; and

(C) during a subsequent normal operating mode;

(i) removing the step function; and

(ii) using the estimator value to estimate flow through the EGR valve.

10. A method for controlling air charge in a direct-injection, spark-ignition engine, such engine having an exhaust gas recirculation (EGR) valve connecting the exhaust manifold and intake manifold of the engine and an electronically controlled throttle (ETC) valve controlling air flow from the atmosphere to the intake manifold of said engine, such method comprising:

(A) measuring an intake manifold pressure value which is indicative of measured intake manifold pressure;

(B) estimating flow into the cylinder as a function of the measured intake manifold pressure;

(C) modifying the estimated flow into the cylinder with a time varying multiplier; and

(D) determining, when the EGR valve is opened, the time varying multiplier as a function of the difference between measured flow through the ETC and the modified estimated flow into the cylinder with a previously determined multiplier.