变速器电液系统分析及颤振电流控制

Transmission Electro-hydraulic System Analysis and Current Dither Control

电液系统是自动变速器的最重要组成部分,它主要由电磁阀、换挡阀、离合器三部分组成,涉及到电子、机械、液压多个物理领域。从动力学的角度分析该系统的动态特性可以提高离合器的控制精度。通过对电液系统的结构进行建模和仿真分析,得到了电液系统的压力与电流的特性曲线,并发现了压力滞环效应。通过分析滞环产生的原因,提出了电磁阀电流的颤振控制,并分析了电磁阀颤振控制的原理。并进行压力滞环实验,验证了颤振电流可以明显减小压力滞缓、提高离合器的压力控制精度。

The electro-hydraulic system is one of the most important parts of automatic transmission. It mainly includes solenoid valve,shift valve and clutch which,involving in electronic,mechanical,and hydraulic fields. The accuracy of clutch pressure control can be improved by analyzing the dynamic characteristics of this the electro-hydraulic system. Through modeling and simulation analysis,the characteristic curves of current and pressure were obtained. Simultaneously,the effect of pressure hysteresis was found. After analyzing the reason of pressure hysteresis,the dither current control of solenoid value was put forward,and the principle of dither current control was introduced. Finally,the result that the dither current control can reduce the effect of pressure hysteresis is verified by the pressure hysteresis test. It means the dither current control can improve the accuracy of pressure control.