Aisan Kogyo Kabushiki Kaisha

Hiroyuki Makisako

Katsumi Ishida

Hiroshi Takamatsu

Takamasa Kitamura

Shigeo Kikori

Yoshiyasu Itoh

An electronic throttle control apparatus is provided with an electronic throttle ( ) including a throttle valve ( ) which is opened and closed by a motor ( ), and a microcomputer ( ) which controls the motor ( ). The microcomputer ( ) calculates a deviation between a target opening degree which is set by detection of an accelerator sensor ( ) and an actual opening degree which is detected by a throttle sensor ( ) to calculate a motor control amount in accordance with the deviation and a control gain in correspondence to the deviation. The microcomputer sets a control gain which becomes smaller as the deviation becomes larger, and limits the control gain by the previous control gain at a time when the control gain is larger than the previous control gain. The microcomputer ( ) cancels the limit of the control gain when the calculated actual opening degree change is reduced from a predetermined value.

Electronic throttle control apparatus

A throttle valve controller achieves high output response to the smaller deviation of the actual opening from the demand opening of the throttle valve and achieves high control stability against the larger deviation. It has a preset data table containing proportional gain values and integral gain values of PID control in correspondence to deviation values in inversely proportional arrangement. During the transitional state of control system, a pair of provisional gain values are read out of the table in response to the deviation value: (step S3), these gain values are compared with those of the previous operation cycle and the smaller gain value pair are selected: (steps S4-S7), and the valve drive signal is calculated from the selected gain values:(steps S8, S11). Consequently, the controller achieves high output response to the smaller deviation due to the larger gain value and high control stability without the overshooting of valve movement against the larger deviation due to the smaller gain value.

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Obu, Japan

Hiroyuki Makisako