US Patent 6848420 Control system for throttle valve actuating device

A control system for a throttle valve actuating device is disclosed. The throttle valve actuating device has a throttle valve of an internal combustion engine and an actuator for actuating the throttle valve. Model parameters of a controlled object model obtained by modeling the throttle valve actuating device is identified by an identifier. The model parameters includes a specific model parameter irrelevant to an input and an output of the controlled object model. An opening of the throttle valve is controlled to a target opening using the identified model parameters. It is determined that the throttle valve actuating device is abnormal when the value of the specific model parameter becomes greater than a predetermined value.