Patent ID: 7730718

Claim:
A control system for an internal combustion engine comprising: an exhaust gas purifying device provided to an exhaust duct of the internal combustion engine; an exhaust gas temperature sensor provided in the exhaust duct on an upstream side of the exhaust gas purifying device; temperature estimating means for estimating a first exhaust gas temperature on a downstream side of the exhaust gas purifying device through a transfer function, which is expressed by a plurality of identical first-order lag elements, based on a second exhaust gas temperature on the upstream side of the exhaust gas purifying device sensed by the exhaust gas temperature sensor; a gas sensor that is provided in the exhaust duct on the downstream side of the exhaust gas purifying device, the gas sensor including a sensor element part, which senses a concentration of a specified component in exhaust gas, and a heater, which heats the sensor element part, wherein an energization control of the heater for energizing the heater is performed in order to maintain the sensor element part under an activation state; and compensating means for compensating influence of exhaust gas heat to the gas sensor based on the first exhaust gas temperature estimated by the temperature estimating means, wherein the compensating means corrects at least one of the sensed concentration sensed by the sensor element part and an energization amount for energizing the heater in the energization control of the heater in order to compensate the influence of the exhaust gas heat to the gas sensor.