Patent attributes
An EGR control apparatus for an internal combustion engine, which is capable of accurately controlling an inert gas amount and an inert gas ratio of two types of EGR gas supplied to cylinders of the engine via two paths different from each other, thereby making it possible to ensure a stable combustion state and reduced exhaust emissions. The EGR control apparatus includes a low-pressure EGR device, a high-pressure EGR device, and an ECU. The ECU calculates a target low-pressure opening, calculates an estimated value of an in-cylinder low-pressure inert gas flow rate, which is the estimated value of an inert gas amount included in low-pressure EGR gas supplied to the cylinders via an intake passage, calculates a target high-pressure opening using the estimated value, and controls low-pressure and high-pressure EGR control valves, using the target low-pressure opening and the target high-pressure opening.
