Intake charge deficit method for engine real-time diagnostics application

• US 7,516,009 B1
• Filed: 09/19/2007
• Issued: 04/07/2009
• Est. Priority Date: 09/19/2007
• Status: Expired due to Fees

• Current Assignee: Detroit Diesel Corporation (Daimler Truck Holding AG)
• Original Assignee: Detroit Diesel Corporation (Daimler Truck Holding AG)
• Inventors: Han, Zhiping
• Primary Examiner(s): Vo; Hieu T
• Application Number:
  US11/857,472
• Publication Number:
  US 20090076715A1
• Time in Patent Office: 566 Days
• Field of Search: 701/114, 701/102, 701/101, 701/115, 606/02, 606/06
• US Class Current: 701/114
• CPC Class Codes: F02D 2250/38 Control for minimising smoke emissions, e.g. by applying smoke limitations on the fuel injection amount
• CPC Class Codes: F02D 41/0007 for control of turbo-charged or super-charged engines control of the pumps per se F02B37/12
• CPC Class Codes: F02D 41/0065 Specific aspects of external EGR control constructional details of EGR system F02M26/00
• CPC Class Codes: F02D 41/10 for acceleration
• CPC Class Codes: F02D 41/18 by measuring intake air flow
• CPC Class Codes: F02D 41/221 relating to the failure of actuators or electrically driven elements
• 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: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

The present invention relates to a method of engine operation to provide a real time engine diagnostic to detect EGR, turbocharger or compressor malfunctions and to prevent such malfunctions from damaging the engine.

Claims

1. A method to operate an internal combustion engine to provide real time diagnostics to detect hardware failures, said internal combustion engine having electronic sensors in communication with said electronic control central unit with memory, unit and variable engine system components including an exhaust gas recirculation valve, said method comprising:

determining a target intake air flow rate based upon target engine operation during exhaust smoke control time period;

determining an actual air intake flow rate based upon actual sensed engine operation during said exhaust smoke control time period;

determining an air mass deficit as an accumulated air intake charge quantity difference between the targeted intake air flow and the actual intake air flow charge during the exhaust smoke control time period according to the formula;

$\mathrm{Air\_mass}<br><br>\mathrm{\_defict}={\int <br><br>}_{\mathrm{smoke\_control}<br><br>\mathrm{\_start}}^{\mathrm{smoke\_control}<br><br>\mathrm{\_end}}<br><br>\left[\left(\mathrm{target\_air}<br><br>\mathrm{\_flow}<br><br>\mathrm{\_rate}\right)-\left(\mathrm{actual\_air}<br><br>\mathrm{\_flow}<br><br>\mathrm{\_rate}\right)\right]<br><br><br><br>d<br><br>t.$

2. The method of claim 1, wherein said smoke control period occurs when engine fueling is limited because of an air intake shortage while engine torque value is below maximum available engine torque value.

3. The method of claim 1, wherein when the intake air mass flow mass deficit exceeds a threshold, at least one of a fault in flagged engine is derated, and a warning is activated to alert operator of fault to protect at least in the ECU one of the engine or engine system components from damage.

4. The method of claim 1, wherein when the air mass flow intake value is operated then an air intake reference value stored in the ECU for the engine during a given operation, a hardware failure causing intake air quality degredation during acceleration is indicated.

5. The method of claim 4 wherein said hardware failure is indicative of at least one of EGR valve stick at least partially open, a turbocharger malfunction, or a compressor malfunction, or EGR loop exhaust leakage, or intake air flow leakage.