Engine nox model
AssigneeInternational Engine Intellectual Property Company, LLC
InventorsAdam C. Lack, Navtej Singh, Prasanna Nagabushan-Venkatesh
Life of this patent
Estimating the term…
Abstract
A method is provided for estimating the NOx content of exhaust gas produced by an internal combustion engine. The method includes determining a first NOx estimate corresponding to the NOx level output by the engine during a first engine operating condition. The method further includes determining a second NOx estimate corresponding to the NOx level output by the engine during a second engine operating condition. The method further includes determining a compensation factor based on intake manifold pressure and applying the compensation factor to the first and second NOx estimates to arrive at a final NOx estimate.
Claims14
A method for estimating the NOx content of exhaust gas produced by an internal combustion engine, the method comprising:
- determining a first NOx estimate corresponding to the NOx level output by the engine during a first engine operating condition;
- determining a second NOx estimate corresponding to the NOx level output by the engine during a second engine operating condition;
- determining a compensation factor based on intake manifold pressure;
- applying the compensation factor to the first and second NOx estimates to arrive at a final NOx estimate.
A method for estimating the NOx content of exhaust gas produced by an internal combustion engine, the method comprising:
- determining a steady state NOx estimate as a function of at least engine speed and torque, the steady state NOx corresponding to the NOx level output by the engine during a substantially steady state operation where engine speed and power are substantially constant;
- determining a transitory NOx estimate as a function of at least engine speed and torque, the transitory NOx estimate corresponding to the NOx level output by the engine during a transitory operation where engine power is increasing;
- determining a compensation factor based on intake manifold pressure;
- applying the compensation factor to the steady state and transitory NO estimates to arrive at a final NOx estimate, wherein the compensation factor weights the final NOx estimate towards the first NOx estimate with decreasing intake manifold pressure.
A method for estimating the NOx content of exhaust gas produced by an internal combustion engine, the method comprising:
- determining a steady state NOx estimate (NOx_SS) as a function of at least engine speed and torque, the steady state NOx corresponding to the NOx level output by the engine during a substantially steady state operation where engine speed and power are substantially constant;
- determining a transitory NOx estimate (NOx_T) as a function of at least engine speed and torque, the transitory NOx estimate corresponding to the NOx level output by the engine during a transitory operation where engine power is increasing;
- determining an estimated intake manifold pressure as a function of at least engine speed and torque;
- sensing the actual intake manifold pressure;
- determining the compensation factor (CF) as a function of a difference between the actual and estimated intake manifold pressures, wherein the compensation factor has a value ranging from 0 to 1 and increases as the difference between the actual and estimated intake manifold pressures increases;
- determining final NOx estimate NOx_OUT_EST in accordance with the following formula:
- NOx_OUT_EST=(CF•NOx_T)+((1−CF)•NOx_SS).
Dependencies are inferred from the claim text.