Patent ID: 6286366
Filing Date: 2001-09-11
Classification: F02D

Abstract:
A method of determining a charge air temperature of a vehicle, said method comprising the steps of:determining an inlet air temperature to a manifold of the vehicle;determining an engine coolant temperature;determining a speed of the vehicle;determining a manifold absolute pressure within the manifold of the vehicle;determining a speed of the vehicle engine;determining an exhaust gas recirculation condition;determining an on/off state of a vehicle engine fan; anddetermining the charge air temperature based on heat transfer and vehicle parameters, including determining the charge air temperature by an equation that uses the inlet air temperature, the engine coolant temperature, the vehicle speed, the manifold pressure, the engine speed, the exhaust gas recirculation condition and the engine fan on/off state as inputs to the equation, wherein the step of determining the charge air temperature includes adding together several heat contribution terms, wherein a first heat contribution term is based on the engine speed, the manifold pressure and the exhaust gas recirculation condition, a second heat contribution term is based on the vehicle speed, the radiator fan on/off state, and the engine coolant temperature, a third heat contribution term is based on the vehicle speed, the radiator fan on/off state and the engine coolant temperature, and a fourth heat contribution term is based on the heat transfer of the manifold, and wherein the equation is: ##EQU6##where f.sub.cv is a coefficient for the first term, f.sub.cd is a coefficient for the second term, f.sub.cr is a coefficient for the third term and f.sub.mr is a coefficient for the fourth term, wherein the coefficients f.sub.cv, f.sub.cd, f.sub.cr, and f.sub.mr are based on vehicle parameters, N is the engine speed, P is the intake manifold pressure, BGR is the exhaust gas recirculation condition, V.sub.s is the vehicle speed, V.sub.f is the radiator fan on/off state, T.sub.c is the engine coolant temperature and T.sub.m is the charge air temperature.