Control method of engine electric air throttle

Abstract

The invention provides a control method of an electronic throttle valve of an engine; wherein, the control method comprises the following steps of: detecting the initial openness or the current openness of the electronic throttle valve; adopting a basic method to control the duty ratio of a PWM signal when the absolute value of the difference value of the initial openness or the current openness of the electronic throttle valve and the target openness is more than X, so as to control rate of change of the openness of opening or closing the electronic throttle valve; and adopting a PID method to control the duty ratio of the PWM signal when the absolute value of the difference value of the initial openness or the current openness of the electronic throttle valve and the target openness is less than or equal to X, so as to control rate of change of the openness of opening or closing the electronic throttle valve; wherein, the range of the X is 2 degrees to 6 degrees. The control method of the electronic throttle valve of the engine can realize the fastness and smoothness of operation of a throttle valve disc when the difference value is more and can realize the accuracy of the operation of the throttle valve disc and prevent overshoot when the difference value is less.

Description

technical field [0001] The invention relates to an engine, and more particularly, to a method for controlling an engine electronic throttle. Background technique [0002] With the increasing development of electronic technology, the increasingly prominent energy issues and environmental issues and the improvement of automotive performance requirements, the electronic throttle has become the most important control device on the fully electronically controlled engine and has begun to be widely used in various vehicles. The advantage is that the throttle valve can be quickly and accurately controlled at the optimal opening according to the driver's desire, emission, fuel consumption and safety requirements, and various control functions can be set to improve driving safety and comfort. [0003] The electronic throttle is a system with nonlinear time-varying damping characteristics, and there are several difficulties in its control: [0004] (1) Non-linear return spring: There ...

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Problems solved by technology

The pulling force of the return spring is the main force to be overcome in the control of the throttle, and the characteristics of the pulling force are also different at both ends of the free position; at the same time, with the increase of the use time of the throttle, the elastic coefficient of the return spring will also change. Changes, so that the general single constant control method will become invalid with the increase of time;

[0005] (2) Uncertainty of friction torque: the friction force in the throttle body is more complex, mainly including the sliding friction and static friction of the transmission shaft, the viscous friction of the transmission gear, and the action time and range are different, so consider the comprehensive consideration of its impact difficulty;

[0006] (3) The transmission gear gap has a great influence on the transmission: due to the control accuracy requirements of the throttle, the gap between the transmission gears may cause the slight vibration of the throttle reed or the lag of the throttle action when fine-tuning the throttle;

[0007] (4) The influence of the intake air flow on the movement of the disc is difficult to calculate: when the air flows through the throttle body, due to the structure of the throttle body, the pressure distribution of the air flow on both sides of the disc will be uneven, resulting in an unbalanced moment. Its size has a nonlinear relationship with the structure of the throttle body, the size of the intake air flow, and the opening of the disc, so it is difficult to function

[0008] (5) Aging of the throttle body: With the increase of the use time of the throttle, its mechanical structure will show aging, such as the opening of the free position may change; and the position sensor of the throttle body is generally a resistive film contact type The sensor will also shift its voltage range as the usage time increases

[0009] Therefore, due to its structural characteristics and working environment and other factors, it is difficult to accurately control the electronic throttle.

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