FUEL CONTROL SYSTEM WITH PURGE GAS MODELING AND INTEGRATION
First Claim
1. A method of controlling the amount of fuel injected into a cylinder of an internal combustion engine to account for fuel vapors contained in purge gas inducted into the cylinder during purging of an evaporative emission control system that includes a charcoal canister which stores evaporative emissions from a fuel tank, the method comprising the steps of:
- determining a first data value that is related to the concentration of fuel vapors contained in the purge gas, obtaining a second data value that is related to a desired total quantity of fuel to be delivered to the cylinder, using said first and second data values to determine a third data value that relates to an amount of non-purge fuel to be delivered to the cylinder during purging of the charcoal canister, determining a fourth data value that is related to an amount of fuel to be supplied by a fuel injector, wherein said fourth data value is determined by applying one or more corrections to said third data value, and operating the fuel injector using a fuel injector control signal that is determined using said fourth data value.
2 Assignments
0 Petitions
Accused Products
Abstract
A fuel control system that estimates the fuel quantity received from purging of an evaporative emission control system and then accounts for the purge fuel in determining the amount of fuel to be injected into a cylinder of an internal combustion engine. Purge fuel quantity is represented by a purge equivalence ratio which is computed based upon an estimate of the hydrocarbon concentration in the purge gas. The hydrocarbon concentration is adaptively learned using an iterative routine that updates the estimate based on the integrated error between the actual and desired air/fuel ratios. Wall wetting and closed loop corrections are applied only to the non-purge fuel portion of the total fuel delivered to the engine cylinder. The closed loop control includes a block learn memory that provides a correction to the factory fuel calibration. The hydrocarbon concentration is updated using the integrated error during purging, whereas the block learn memory is updated using the integrated error during periods when no purging is occurs. The evaporative emission control system includes a solenoid-operated purge valve that is controlled in a manner that provides improved fuel control during transient conditions. The solenoid duty cycle is controlled using a purge factor that operates to reduce the duty cycle when the intake airflow rate drops significantly.
-
Citations
25 Claims
-
1. A method of controlling the amount of fuel injected into a cylinder of an internal combustion engine to account for fuel vapors contained in purge gas inducted into the cylinder during purging of an evaporative emission control system that includes a charcoal canister which stores evaporative emissions from a fuel tank, the method comprising the steps of:
-
determining a first data value that is related to the concentration of fuel vapors contained in the purge gas, obtaining a second data value that is related to a desired total quantity of fuel to be delivered to the cylinder, using said first and second data values to determine a third data value that relates to an amount of non-purge fuel to be delivered to the cylinder during purging of the charcoal canister, determining a fourth data value that is related to an amount of fuel to be supplied by a fuel injector, wherein said fourth data value is determined by applying one or more corrections to said third data value, and operating the fuel injector using a fuel injector control signal that is determined using said fourth data value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A method of controlling the amount of fuel injected into a cylinder of an internal combustion engine to account for fuel vapors contained in purge gas inducted into the cylinder during purging of an evaporative emission control system that includes a charcoal canister which stores evaporative emissions from a fuel tank, the method comprising the steps of:
-
determining a first data value that is related to the concentration of fuel vapors contained in the purge gas, determining a second data value that is related to the amount of non-purge fuel to be delivered to the cylinder, calculating a third data value using said second data value and a closed loop correction factor, injecting fuel into the cylinder for subsequent combustion, wherein the quantity of injected fuel is determined in accordance with said third data value, generating a closed loop feedback using a measurement of gases exhausted from the cylinder following combustion, and using said feedback to iteratively update said first data value during purging and to iteratively update said correction factor during periods when no purging occurs. - View Dependent Claims (12, 13, 14, 15)
-
-
16. A method for determining the concentration of fuel vapor contained in purge gas inducted into a cylinder of an internal combustion engine during purging of an evaporative emission control system, the method comprising the steps of:
-
(a) obtaining a data value representative of the concentration of purge fuel vapors in the purge gas, (b) operating a purge valve to permit the purge gas to be drawn into the cylinder of the internal combustion engine, (c) determining an additional amount of fuel to be injected into the cylinder using said data value, (d) injecting said additional fuel into the cylinder, and (e) adjusting said data value if the total amount of fuel provided to the cylinder is greater than or less than a desired amount of fuel. - View Dependent Claims (17, 18, 19, 20, 21, 22)
-
-
23. A method of controlling a solenoid-actuated charcoal canister purge valve to limit the portion of fuel that is supplied via the purge valve to a cylinder of an internal combustion engine, the method comprising the steps of:
-
determining a duty cycle for use in energizing the solenoid-actuated purge valve, said duty cycle being determined in accordance with an intake airflow and a purge factor, energizing the solenoid-actuated purge valve using the duty cycle to thereby supply a quantity of purge fuel to the cylinder, supplying an additional quantity of fuel to the cylinder, whereby the total fuel supplied to the cylinder includes said purge fuel and said additional quantity of fuel, determining a purge equivalent ratio that is related to the percentage of the total fuel that comprises purge fuel, and decreasing said purge factor if said purge equivalence ratio is greater than a selected percentage and increasing said purge factor if said purge equivalence ratio is less than a selected percentage. - View Dependent Claims (24, 25)
-
Specification