Methods and apparatus for estimating gas temperatures within a vehicle engine

A method for estimating a plurality of gas temperatures in an engine of a vehicle, comprising:

• receiving a velocity of the vehicle and an air mass flow rate;
• estimating an exhaust gas temperature based at least upon said velocity of the vehicle and said air mass flow rate;
• receiving an EGR mass flow rate;
• estimating an EGR gas temperature at a EGR valve based at least upon said exhaust gas temperature and said EGR mass flow rate;
• estimating an EGR gas temperature at a throttle body based at least upon said exhaust gas temperature and said EGR mass flow rate;
• and
• estimating a charge temperature based at least upon said EGR gas temperature at said throttle body, said velocity of the vehicle, and said EGR mass flow rate.

An apparatus for estimating a plurality of gas temperatures in an internal combustion engine of an automobile, comprising:

• an exhaust temperature estimator configured to receive a velocity of the vehicle and an air mass flow rate, said exhaust temperature estimator configured to estimate an exhaust gas temperature based at least upon said velocity of the vehicle, said air mass flow rate, an EGR mass flow rate and an engine velocity, said exhaust temperature estimator comprising:
• an air temperature estimator configured to generate an air temperature estimate based at least upon said air mass flow rate and said velocity of the vehicle;
• an EGR gas temperature estimator configured to generate an EGR temperature estimate based at least upon an EGR ratio and the velocity of the vehicle;
• a spark effect determinator configured to generate an effect of engine spark on temperature estimate based at least upon air mass flow rate and an engine speed;
• and
• an exhaust temperature summer configured to produce said exhaust gas temperature from said air temperature estimate, EGR temperature estimate, and said effect of engine spark on temperature estimate;
• a first recirculated engine exhaust gas (EGR) temperature estimator coupled to said exhaust temperature estimator, said first EGR temperature estimator configured to receive said exhaust gas temperature from said exhaust temperature estimator and further configured to receive an EGR mass flow rate, said first EGR temperature estimator configured to estimate an EGR gas temperature at an EGR valve of the engine based at least upon said exhaust gas temperature and said EGR mass flow rate;
• a second EGR temperature estimator coupled to said exhaust temperature estimator, said second EGR temperature estimator configured to receive said exhaust gas temperature from said exhaust temperature estimator and further configured to receive said EGR mass flow rate, said second EGR temperature estimator configured to estimate an EGR gas temperature at a throttle body of the engine based at least upon said exhaust gas temperature and said EGR mass flow rate;
• and
• a charge temperature estimator coupled to said second EGR temperature estimator, said charge temperature estimator configured to receive said EGR gas temperature at said throttle body from said second EGR temperature estimator, said charge temperature estimator further configured to receive said velocity of the vehicle and said EGR mass flow rate, said charge temperature estimator configured to estimate a charge gas temperature based at least upon said EGR gas temperature at said throttle body, said velocity of the vehicle, said EGR mass flow rate, an engine coolant temperature and an engine inlet temperature.