BEOWDETAILED ACTION
Specification
The disclosure (specification) is objected to because it is unclear. Going forward with examination, the following specification paragraphs are interpreted to be (Please also see the 112 rejections below):
Paragraph beginning on page 2, line 1:
--For determining the target value for secondary air injection, a target value for combustion chamber lambda (raw emissions from the internal combustion engine) along with a target value for exhaust gas lambda (catalytic converter capability) are specified, for example. The required secondary air volume, for example, can then be determined from the ratio of the two lambda target values and a current exhaust gas mass flow.--
Paragraph beginning on page 2, line 8:
--In the diagnosis of the secondary air system, the actual secondary air mass flow determined from the measured pressure in the secondary air system is monitored. When actively conveying a secondary air mass flow against a closed secondary air valve, the pressure in the secondary air system must be increased and the actual secondary air mass flow modeled therefrom is estimated by a reduced purge gradient. When the secondary air valve is opened, a positive secondary air mass flow is expected according to the purge gradient.--
Paragraphs beginning on page 3, line 3, and ends on page 6, line 29:
--According to a first aspect of the present invention, a method for monitoring a secondary air supply in an internal combustion engine is provided, wherein the internal combustion engine comprises the secondary air supply, a device for determining a pressure in the secondary air supply and an exhaust gas lambda probe for determining a current exhaust gas lambda value. According to an example embodiment of the present invention, the method comprises the following steps:
a) determining, with the aid of a throttle equation and according to a pressure in the secondary air supply, a first secondary air mass flow in relation to the effective throttle area;
b) determining a second secondary air mass flow based on the measured exhaust gas lambda value and taking into account a primary air mass flow of the internal combustion engine and a supplied fuel mass flow;
c) deriving the effective throttle area from the throttle equation in step a) and the second secondary air mass flow determined in step b) by substituting the first secondary air mass flow in the throttle equation with the second air mass flow;
d) monitoring the effective throttle area obtained in this way using at least one specified threshold value.
In the method for monitoring the secondary air supply according to an example embodiment of the present invention, the secondary air mass flow in the secondary air supply is determined in two different ways. In the first way, by means of a throttle equation using pressure ratios between two pressures across a throttle in the secondary air supply in the exhaust system at a given time, the secondary air mass flow is determined as a first secondary air mass flow in relation to an effective throttle area of the throttle. In other words, the throttle equation determines a relationship between the secondary air mass flow and the effective throttle area of the throttle. For instance, one may expect that the larger the effective throttle area is, the higher the secondary air mass flow becomes. In an ideal situation where no leak, for example, exists in the secondary air supply, this effective throttle area would be equal to a controlled known throttle area of the throttle. In the second way, the secondary air mass flow in the secondary air supply is determined as a second secondary air mass flow based on the measured exhaust gas lambda value. After the secondary air mass flow has been determined in the second way, the effective throttle area is derived from the throttle equation by substituting the first secondary air mass flow in the throttle equation with the second secondary air mass flow. The derived effective throttle area obtained in this way is suitable for diagnosing the secondary air system. By means of at least one specified threshold value, it can be monitored whether the derived effective throttle area is within an expected range in relation to the controlled known throttle area of the throttle. If the derived effective throttle area leaves the expected range, it could be concluded, for example, that there is a malfunction in the secondary air system, such as a leak. Monitoring the derived effective throttle area allows for precise monitoring of the secondary air system during operation and early recognition of malfunctions.
In addition, the present invention relates to a diagnostic system for a secondary air supply in an internal combustion engine, wherein the internal combustion engine comprises: the secondary air supply for supplying secondary air, a device for determining the pressure in the secondary air supply, an exhaust gas lambda probe for determining a current exhaust gas lambda value, and an evaluation device. According to an example embodiment of the present invention, the evaluation device is designed:
a) to determine a first secondary air mass flow in relation to the effective throttle area with the aid of a throttle equation and according to a pressure in the secondary air supply;
b) to determine a second secondary air mass flow based on the measured exhaust gas lambda value and taking into account the primary air mass flow of the internal combustion engine and the supplied fuel mass flow;
c) deriving the effective throttle area from the throttle equation in step a) and the second secondary air mass flow determined in step b) by substituting the first secondary air mass flow in the throttle equation with the second air mass flow;
d) to monitor the effective throttle area obtained in this way using at least one specified threshold value.
It is advantageous if the first secondary air mass flow is determined in step a) by means of the throttle equation which relates the first secondary air mass flow to the pressure in the secondary air supply and the effective throttle area.
Preferably, the derivation of the effective throttle area in step c) is effected with the aid of a mass flow balance according to an exhaust gas lambda value.
Further preferably, the derivation of the effective throttle area in step c) is effected taking into account the temporal dynamics of the exhaust gas lambda probe.
According to a preferred embodiment of the present invention, the derivation of the effective throttle area in step c) is effected using the recursive least mean square (LMS) method or the recursive normalized least mean square (NLMS) method. The use of such recursive methods allows for an exact determination of the effective throttle area.
Preferably, the difference between the secondary air mass flow derived from the pressure and the secondary air mass flow derived from the exhaust gas lambda value is used as the error term of the recursive least mean square (LMS) method or the recursive normalized least mean square (NLMS) method.
According to a preferred embodiment of the present invention, a leak is recognized for monitoring in the event that the effective throttle area is greater than a specified first threshold value.
According to a preferred embodiment of the present invention, a jamming or clogging of the secondary air valve is recognized in the event that the effective throttle area is smaller than a specified second threshold value.
According to a further aspect of the present invention, a diagnostic system is provided for a secondary air supply in an internal combustion engine, wherein the internal combustion engine comprises:
the secondary air supply for supplying secondary air,
a device for determining the pressure in the secondary air supply, [0033] an exhaust gas lambda probe for determining a current exhaust gas lambda value,
an evaluation device that is designed
a) to determine a first secondary air mass flow in relation to the effective throttle area with the aid of a throttle equation and according to a pressure in the secondary air supply;
b) to determine a second secondary air mass flow based on the measured exhaust gas lambda value and taking into account the primary air mass flow of the internal combustion engine and the supplied fuel mass flow;
c) deriving the effective throttle area from the throttle equation in step a) and the second secondary air mass flow determined in step b) by substituting the first secondary air mass flow in the throttle equation with the second air mass flow;
d) to monitor the effective throttle area obtained in this way using at least one specified threshold value.--
Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
Claims 1-11 are rejected under 35 U.S.C. 112(a) as failing to comply with the enablement requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to enable one skilled in the art to which it pertains, or with which it is most nearly connected, to make and/or use the invention.
Independent claims 1 and 9-11 essentially recite:
“…c) deriving the effective throttle area from the first secondary air mass flow determined in step a) and the second secondary air mass flow determined in step b)….”
However, it appears that the first secondary air mass flow is unknown before deriving the effective throttle area. So, it appears impossible to derive the effective throttle from the unknown first secondary air mass flow (It is impossible to derive an unknown from another unknown).
Going forward with examination, the claims 1-11 are interpreted to be:
1. A method for monitoring a secondary air supply (3) in an internal combustion engine (1), wherein the internal combustion engine (1) includes the secondary air supply (3), a device (5) configured to determine a pressure in the secondary air supply (3), and an exhaust gas lambda probe (4) configured to determine a current exhaust gas lambda value, wherein the method comprises the following steps:
a) determining, using a throttle equation and according to a pressure in the secondary air supply (3), a first secondary air mass flow in relation to an effective throttle area;
b) determining a second secondary air mass flow based on a measured exhaust gas lambda value and taking into account a primary air mass flow of the internal combustion engine and a supplied fuel mass flow;
c) deriving the effective throttle area from the throttle equation in step a) and the second secondary air mass flow determined in step b) by substituting the first secondary air mass flow in the throttle equation with the second air mass flow; and
d) monitoring the effective throttle area derived in step c) using at least one specified threshold value.
--2. The method according to claim 1, wherein relates to the pressure in the secondary air supply (3) and the effective throttle area.--
--3. The method according to claim 1, wherein the derivation of the effective throttle area in step c) uses a mass flow balance according to the exhaust gas lambda value.--
--4. The method according to claim 1, wherein the derivation of the effective throttle area in step c) takes into account temporal dynamics of the exhaust gas lambda probe.--
--5. The method according to claim 1, wherein the derivation of the effective throttle area in step c) uses a recursive least mean square (LMS) method or a recursive normalized least mean square (NLMS) method.--
--6. The method according to claim 5, wherein a difference between the first secondary air mass flow derived from the pressure after the effective throttle area is derived and the second secondary air mass flow derived from the exhaust gas lambda value is used as an error term of the recursive least mean square (LMS) method or the recursive normalized least mean square (NLMS) method.--
--7. The method according to claim 1, wherein a leak is recognized when the effective throttle area is greater than a specified first threshold value.--
--8. The method according to claim 1, wherein a jamming or clogging of the secondary air supply is recognized when the effective throttle area is smaller than a specified second threshold value.--
--9. A diagnostic system for a secondary air supply in an internal combustion engine, wherein the internal combustion engine comprises:
the secondary air supply configured to supply secondary air;
a device configured to determine a pressure in the secondary air supply;
an exhaust gas lambda probe configured to determine a current exhaust gas lambda value; and an evaluation device configured to:
a) determine a first secondary air mass flow in relation to an effective throttle area using a throttle equation and according to the pressure in the secondary air supply;
b) determine a second secondary air mass flow based on a measured exhaust gas lambda value and taking into account a primary air mass flow of the internal combustion engine and a supplied fuel mass flow;
c) deriving the effective throttle area from the throttle equation in step a) and the second secondary air mass flow determined in step b) by substituting the first secondary air mass flow in the throttle equation with the second air mass flow; and
d) monitor the effective throttle area derived in step c) using at least one specified threshold value.--
--10. An exhaust system of an internal combustion engine, comprising: a diagnostic system for a secondary air supply in an internal combustion engine, wherein the internal combustion engine includes: the secondary air supply configured to supply secondary air; a device configured to determine a pressure in the secondary air supply; an exhaust gas lambda probe configured to determine a current exhaust gas lambda value; and an evaluation device configured to:
a) determine a first secondary air mass flow in relation to an effective throttle area using a throttle equation and according to the pressure in the secondary air supply;
b) determine a second secondary air mass flow based on a measured exhaust gas lambda value and taking into account a primary air mass flow of the internal combustion engine and a supplied fuel mass flow;
c) derive the effective throttle area from the throttle equation in step a) and the second secondary air mass flow determined in step b) by substituting the first secondary air mass flow in the throttle equation with the second air mass flow; and
d) monitor the effective throttle area derived in step c) using at least one specified threshold value.--
--11. A non-transitory machine-readable storage medium on which store stored commands for monitoring a secondary air supply in an internal combustion engine, wherein the internal combustion engine includes the secondary air supply, a device configured to determine a pressure in the secondary air supply, and an exhaust gas lambda probe configured to determine a current exhaust gas lambda value, the commands, when executed by at least one data processor, causing the at least one data processor to perform the following steps:
a) determining, using a throttle equation and according to a pressure in the secondary air supply, a first secondary air mass flow in relation to an effective throttle area;
b) determining a second secondary air mass flow based on a measured exhaust gas lambda value and taking into account a primary air mass flow of the internal combustion engine and a supplied fuel mass flow;
c) deriving the effective throttle area from the throttle equation in step a) and the second secondary air mass flow determined in step b) by substituting the first secondary air mass flow in the throttle equation with the second air mass flow; and
d) monitoring the effective throttle area derived in step c) using at least one specified threshold value.--
Allowable Subject Matter
Claims 1-11 would be allowed if the above objections and rejections were overcome. The following would be an examiner’s statement of reasons for allowance:
With respect to independent claims 1 and 9-11, prior art of record doesn’t teach, suggest, or render obvious the total combination of the recited features, including the following allowable subject matter (or an equivalent):
“…
a) determining, using a throttle equation and according to a pressure in the secondary air supply (3), a first secondary air mass flow in relation to an effective throttle area;
b) determining a second secondary air mass flow based on a measured exhaust gas lambda value and taking into account a primary air mass flow of the internal combustion engine and a supplied fuel mass flow;
c) deriving the effective throttle area from the throttle equation in step a) and the second secondary air mass flow determined in step b) by substituting the first secondary air mass flow in the throttle equation with the second air mass flow; and
d) monitoring the effective throttle area derived in step c) using at least one specified threshold value.”
(The remaining claims are dependent on claim 1.)
Conclusion
The prior art made of record below and not relied upon is considered most pertinent to applicant’s disclosure/invention.
DE 10 2016 119 816 A1 to Zink discloses a method/system for monitoring a secondary air supply system (50; Fig. 1, reproduced below) in an internal combustion engine (10), wherein the internal combustion engine includes the secondary air supply system (50), and an exhaust gas lambda probe (oxygen sensor 42, 44) configured to determine a current exhaust gas lambda value.
The lambda probe (42, 44) determines a residual oxygen content in the exhaust gas duct (36). Then it is concluded, on the basis of the determined residual oxygen content in the exhaust gas duct (36), a correct functioning of the secondary air system (50).
Based on the determined lambda value, the method/system determines whether there is a deviation of the residual oxygen content in the exhaust gas duct (36) from a residual oxygen content to be expected in the case of correct function. The method/system thus may conclude an error in the secondary air system (50) and output a corresponding error signal.
Zink and the present invention appear to obtain similar monitoring results but in two distinct ways patentable over each other.
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Any inquiry concerning this communication or earlier communications from the examiner should be directed to Nguyen (Wyn) Q. Ha whose telephone number is (571) 272-2863, email: nguyenq.ha@uspto.gov. The examiner can normally be reached Monday - Friday 8 am - 4:30 pm (Eastern Time).
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Stephen Meier can be reached at (571) 272-2149. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/Nguyen Q. Ha/Primary Examiner, Art Unit 2853 September 21, 2026
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