초록 ▼

A method for calculating an actual fresh-air mass flowing into a cylinder with the aid of an inlet pipe flow model. The description of the flow model is based on a nonlinear differential equation. The chosen model approach contains modeling of an external exhaust-gas recycling system, variable inlet

A method for calculating an actual fresh-air mass flowing into a cylinder with the aid of an inlet pipe flow model. The description of the flow model is based on a nonlinear differential equation. The chosen model approach contains modeling of an external exhaust-gas recycling system, variable inlet systems and systems with variable control valves. The model-assisted load detection method can be used in engine control systems based on air mass flow and on inlet pipe pressure. A correction algorithm, in the form of a model control loop allows permanent improvement of accuracy when the model parameters are inexact. That is to say model balancing is provided in steady and unsteady operational states.

대표청구항 ▼

[ We claim:] [1.] In a process for determining a quantity of fresh-air mass flowing into a cylinder of an internal combustion engine, the internal combustion engine having an inlet pipe, a throttle valve, a first sensor device for detecting a degree of opening of the throttle valve, an exhaust-gas r

[ We claim:] [1.] In a process for determining a quantity of fresh-air mass flowing into a cylinder of an internal combustion engine, the internal combustion engine having an inlet pipe, a throttle valve, a first sensor device for detecting a degree of opening of the throttle valve, an exhaust-gas recycling device with an exhaust-gas recycling valve, a second sensor device for detecting a degree of opening of the exhaust-gas recycling valve, a load sensor producing a load signal, and an electronic control device calculating a basic injection time on a basis of the load signal and a speed of the internal combustion engine, the improvement which comprises:reproducing conditions in the inlet pipe using an inlet pipe flow model, and using the degree of opening of the throttle valve, the degree of opening of the exhaust-gas recycling valve, an ambient pressure, an exhaust-gas temperature, a temperature in the inlet pipe and parameters representing a valve setting as input variables of the inlet pipe flow model;forming a model variable for an air mass flow at the throttle valve and for a residual-gas mass flow at the exhaust-gas recycling valve;forming a model variable for an air mass flow into the cylinder as a function of an inlet pipe pressure;forming a model variable for a residual-gas mass flow into the cylinder as a function of a residual-gas partial pressure;calculating the inlet pipe pressure as a decisive variable for determining an actual load of the internal combustion engine from the model variables of air mass flow at the throttle valve, the residual-gas mass flow at the exhaust-gas recycling valve and the air mass flow into the cylinder;calculating the residual-gas partial pressure in the inlet pipe from the model variables of the residual-gas mass flow at the exhaust-gas recycling valve and the residual-gas mass flow into the cylinder;determining a fresh-gas partial pressure from the inlet pipe pressure and the residual gas partial pressure; andderiving a total air mass flowing into the cylinder by integrating a relationship between the fresh-gas partial pressure and a fresh-air mass flow into the cylinder.