Apparatus for controlling internal combustion engine having turbocharger

摘要

In the control device, a relationship of a throttle-upstream pressure with respect to an exhaust-gas amount is used in a state where a supercharge pressure becomes the lowest by a WG-instruction value with respect to a WGV-control component 220 for driving a WGV 33a provided at a bypass passage 33 bypassing a turbocharger 32, and a relationship of a throttle-upstream pressure with respect to an aperture of a throttle valve 23, a rotational speed of an engine, and an intake-manifold pressure is used, and any of the throttle-upstream pressures, whichever is higher, being calculated in accordance with each of the relationship, is defined as a throttle-upstream-estimation value, whereby the throttle-upstream pressure is estimated by a cheap means with high accuracy so as to control the engine.

主权项

1. An apparatus comprising:
a throttle valve that is provided at an intake air passage of an internal combustion engine; a throttle aperture sensor configured to detect an aperture of the throttle valve; a turbocharger having a compressor provided at an upstream side of the throttle valve, and a turbine provided at an exhaust passage of the internal combustion engine, the compressor being integrally rotated with the turbine; a waste-gate valve that is provided at a bypass passage bypassing around the turbine; an intake manifold pressure sensor configured to detect a pressure in an intake-manifold component that is provided at a downstream side of the throttle valve; and an electronic control unit (ECU) which is configured to: control modification of a flow-passage-cross-sectional area of the bypass passage by controlling the waste-gate valve; determine an intake-air amount in the internal combustion engine; calculate a required output that is required for the internal combustion engine, based on a rotational speed of the internal combustion engine and an accelerator operation of a driver; calculate a target-intake-air quantity passed through the throttle valve in accordance with the required output, and control an effective aperture area of the throttle valve in order to realize the target-intake-air quantity; and estimate a supercharge pressure at a downstream side of the compressor and at the upstream side of the throttle valve, by: calculating an exhaust-gas amount in accordance with a ratio of air to fuel and the intake-air amount in the internal combustion engine; calculating a WG0P2-estimation value, which is the supercharge pressure in a waste-gate-valve-driving condition in a state where the waste-gate valve is provided with an instruction of a 0% duty cycle, in accordance with the exhaust-gas amount; calculating a CALP2-estimation value, which is the supercharge pressure in a region, which includes an operation region where an intake air is more supercharged than the intake air in a region that can be estimated by the calculating the WG0P2-estimation value, in accordance with the effective aperture area, the rotational speed of the internal combustion engine, and the pressure in the intake-manifold component, regardless of a driving condition of the waste-gate valve; and defining the WG0P2-estimation value or the CALP2-estimation value, whichever is higher, as a final-estimation-supercharge-pressure value, wherein the waste-gate valve is controlled based on the final-estimation-supercharge-pressure value.