液压机械无级变速器速比跟踪控制系统研究

提出液压机械无级变速器速比跟踪控制系统的设计方法.分析了等差式液压机械无级变速器的速比特性,建立了液压机械无级变速器的变速系统模型,并通过频率特性分析对液压机械无级变速器的模型进行了简化.设计了速比跟踪控制算法,在实验台上完成了变速器的速比跟踪控制实验以及速比跟踪系统对发动机转速的调节实验.实验结果表明:液压机械无级变速器在跟踪阶跃速比时,不存在稳态跟踪误差,而在跟踪斜坡速比时,存在稳态跟踪误差;通过跟踪变速器的目标速比可以实现对发动机工作转速的调节,使其工作在最佳工作点.

A Study on the Speed Ratio Follow-Up Control System of Hydro-Mechanical Transmission

The designing of speed ratio follow-up control system of hydro-mechanical transmission is given.The speed ratio characteristics of geometric type hydro-mechanical transmission is analyzed,and the model of speed adjusting system of hydro-mechanical transmission is built up.By analyzing the frequency behavior,the model of hydro-mechanical transmission is simplified and based on it,the control algorithm is designed.Finally,the speed ratio follow-up control and the performance of engine speed adjustment with speed ratio follow-up system were tested.Test results showed that there does not exist steady-state error when following the step speed ratio,but steady-state error do exist when following ramp speed ratio,and by following the speed ratio of hydro-mechanical transmission,the desired speed of engine can be achieved.