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US 2014/0109883 A1Published application
Lambda feedback control for robust particulate emissions performance
AssigneeCummins Inc.
InventorsYongjie Zhu, Vivek Anand Sujan, Govindarajan Kothandaraman
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Abstract
Methods are disclosed for reducing the variability of particulate emissions in an exhaust stream from an internal combustion engine using a lambda error and/or a NOx error to control an exhaust gas recirculation fraction and/or a mass charge flow control. The methods include operating a controller to adjust the engine gas recirculation fraction and/or the mass charge flow control.
Claims27
A method, comprising:
- operating an internal combustion engine having an exhaust stream, an exhaust gas recirculation (EGR) stream, and an exhaust NOx feedback value;
- interpreting an engine speed value and an engine load value, and determining a target NOx value in response to the engine speed value and the engine load value;
- determining a NOx error value in response to the target NOx value and the exhaust NOx feedback value;
- and
- operating a proportional-integral (PI) or a proportional-integral-derivative (PID) controller on the NOx error value, and controlling an EGR fraction in response to the PI or PID controller output.
2 more elements
A method, comprising:
- operating an internal combustion engine having an exhaust stream, an exhaust gas recirculation (EGR) stream, an exhaust NOx feedback value, and an O2 feedback value;
- interpreting an engine speed value and an engine load value, and determining a target NOx value in response to the engine speed value and the engine load value;
- determining a NOx error value in response to the target NOx value and the exhaust NOx feedback value;
- operating a feedback controller on the NOx error value, and controlling an EGR fraction in response to a feedback controller output;
- determining a lambda (λ) target value in response to the engine speed value and load value;
- determining a λ error value in response to the λ target value and the O2 feedback value;
- and
- adjusting the operations of the feedback controller in response to the λ error value.
5 more elements
A method, comprising:
- operating an internal combustion engine having an exhaust stream, an exhaust gas recirculation (EGR) stream, an exhaust NOx feedback value, and an O2 feedback value;
- interpreting an engine speed value and an engine load value, and determining a target NOx value in response to the engine speed value and the engine load value;
- determining a NOx error value in response to the target NOx value and the exhaust NOx feedback value;
- determining a lambda (λ) target value in response to the engine speed value and load value;
- determining a λ error value in response to the λ target value and the O2 feedback value;
- and
- operating a two-input two-output controller, comprising the NOx error value as a first input and the λ error value as a second input to the two-input two-output controller, and comprising an EGR tuning factor as a first output and a mass charge flow (MCF) tuning factor as a second output of the two-input two-output controller.
4 more elements
A method, comprising:
- operating an internal combustion engine;
- determining a lambda (λ) target value as a function of an engine speed and an engine load;
- determining a λ error value in response to the λ target value and an O2 sensor output or a NOx sensor output;
- and
- adjusting an exhaust gas recirculation (EGR) fraction to control the λ error value.
2 more elements
Dependencies are inferred from the claim text.