Method and apparatus for controlling exhausted gas emissions during cold-start of an internal combustion engine
AssigneeSouthwest Research Institute
InventorsYiqun Huang, Joseph Grogan
Life of this patent
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Abstract
An in-cylinder ion sensor provides a signal representative of the air/fuel ratio of the charge mixture as an engine starts. The signal representative of the air/fuel ratio is used as a feedback signal for an electronic control unit to perform cold-start closed-loop control during an initial operating period from a cold-start before an on-board oxygen sensor is able to warm up. After reaching a functional operating temperature, the oxygen sensor provides a signal that is used as an adaptive calibration tool which allows the electronic control unit to calibrate the ion sensor signal and use that signal for controlling the air/fuel ratio during cold start operation.
Claims12
A method for controlling exhaust gas emissions during cold start of an internal combustion engine having an ion sensor disposed in intimate communication with at least one combustion chamber of the engine, said method comprising:
- introducing a mixture of air and fuel into the combustion chamber of the engine;
- combusting the mixture of air and fuel in the combustion chamber;
- generating positively charged ions having a value representative of the oxygen content of the combusted mixture of air and fuel;
- sensing the magnitude of ions existent in the combusted mixture of air and fuel and generating a first signal correlative of magnitude of ions existent in the combusted mixture of air and fuel;
- comparing the value of the first signal correlative of the magnitude of ions existent in the combusted air and fuel mixture with a value representative of a desired magnitude of ions in an idealized combusted air and fuel mixture for the mitigation of undesirable products of combustion in exhaust gases discharged from said engine;
- determining a difference between the first signal and the desired value of the first signal;
- generating a second signal correlative of the difference between the first signal and the desired value of the first signal;
- and
- adjusting the air to fuel ratio of the mixture introduced into said combustion chamber in accordance with the value of said second signal.
An apparatus for controlling exhaust gas emissions during cold start of an internal combustion engine having at least one combustion chamber, said apparatus comprising:
- an ion sensor disposed in intimate fluid communication with the combustion chamber;
- an engine control unit adapted to receive a signal from said ion sensor representative of the magnitude of ions existent in a mixture of air and fuel combusted within said combustion chamber, compare the value of the signal received from the ion sensor with a desirable value of ions in a combusted air and fuel mixture for mitigation of undesirable products of combustion in exhaust gases discharged from said engine, and generate control signals representative of the difference between the sensed value of the signal received from the oxygen sensor and the desired value of ions in the combusted mixture;
- and
- a fuel injector disposed in fluid communication with the combustion chamber adapted to receive one of the control signals generated by the engine control unit and inject fuel into said engine in accordance with said control signal.
Dependencies are inferred from the claim text.