• CN:11-2187/TH
  • ISSN:0577-6686

›› 2014, Vol. 50 ›› Issue (24): 179-185.doi: 10.3901/JME.2014.24.179

• 论文 • 上一篇    下一篇



  1. 太原科技大学电子信息工程学院 太原理工大学新型传感器与智能控制教育部与山西省重点实验室
  • 出版日期:2014-12-20 发布日期:2014-12-20

Modeling of Hydraulic Valve-controlled Cylinder Power Mechanism Based on Flow Approximation

BAI Yanhong; QUAN Long; HAO Xiaoxing; LI Hui   

  • Online:2014-12-20 Published:2014-12-20

摘要: 由于非对称缸两腔的非对称性,采用与对称缸类似的方法建立其工作点线性模型时,需要对两腔压力微分做更多的近似处理,模型误差较大。在液压缸负载流量线性方程推导过程中,提出采用对两腔流量进行近似处理的方法,得到适用于不同活塞位置的阀控非对称缸统一模型;应用于对称缸,所得结果与采用传统方法得到的相同,表明所得非对称缸模型误差较小。将零位附近负重叠区内伺服阀中液压油通流状态看作液压缸正反向运行时的两种通流流态共存,得出零位附近的流量增益和流量-压力系数计算公式。不同活塞位置、不同阀芯位移等多个工作点仿真测取的模型参数与理论计算结果相差很小,不同工作点的闭环控制试验曲线与基于理论计算模型的仿真曲线一致,表明所得阀控缸模型误差小。

关键词: 阀控非对称缸, 负载流量方程, 流量近似, 线性模型

Abstract: Because of the asymmetry characteristics of asymmetric cylinders, more approximate treatments for differential of the pressure in two chambers are needed when deducing its local linear models around working points when adapting the same method with that usually used for symmetrical cylinders, which leads to larger model error. Approximate treatments for two chambers flow are introduced to get the linear equation of load flow, by which a unified model suitable for different piston locations is obtained. Symmetric cylinder model derived by this method is identical with that obtained by traditional method, which further implies that the established model has smaller error. Flow gain and flow-pressure coefficient formulas at center position of servo valves are deduced by regarding the complicated oil flowing state as coexistence of two flowing states responding to two moving directions of cylinders outside the overlap area of servo valves. At different working points with different piston locations and different valve spool positions, the difference between model parameters obtained by simulations and theoretical results calculated by the proposed formulas are much small. Response curves in closed loop control experiments are consistent with those in simulations based on theoretical models at different working points. The above results show that the proposed valve-controlled asymmetric cylinder model has smaller error.

Key words: flow approximation, linear model, load flow equation, valve-controlled asymmetric cylinder