System and method for smooth transitions between engine mode controllers

摘要

A system and method for controlling an internal combustion engine using a controller to implement at least two control modes having corresponding first and second mode controllers with disparate control parameters include comparing output of the first and second mode controllers to generate an error, generating a correction value based on the error, and providing the correction value to one of the mode controllers to provide a smooth transition of control between the mode controllers. In one embodiment, the first controller is a torque controller which determines a desired air flow to achieve a desired torque and the second mode controller is an idle speed controller which determines a desired air flow to maintain a desired engine speed. The invention is advantageous in that it provides for smooth transitions between control modes, such as between idle mode and a normal driving mode, by harmonizing the outputs of the controllers. Drivability is improved by eliminating an aggressive and/or sluggish response to accelerator pedal position when transitioning between idle speed control and normal driving modes.