一种机/液复合驱动系统的非对称双缸设计

Designing Hydromechanical Hybrid Actuator with Asymmetric Double Cylinders

为了满足狭小空间下液压驱动远程、高柔性的特殊要求,提出一种机/液复合的非对称双液压缸方案。该方案采用双微型液压缸经细长软管并联,电机驱动滚珠丝杠推动力源缸移动,由两缸间建立的油压驱动目标缸位移,构成非对称双缸驱动。分别构建开环及闭环控制系统,为获得理想的稳态与动态性能,考虑软管形变的影响对该系统进行了AMESim建模与仿真。结果表明,微型缸的连接软管引起较长的启动死区并降低了回程复位精度及动态特性。在双缸结构参数完全一致的基础上,采用适当比例的非对称双缸设计可改善上述性能并保证系统稳定性。

In order to meet the special requirements for the remote and highly flexible actuation of a hydraulic device in a small area,a hydromechanical hybrid actuator with asymmetric double cylinders is proposed.Thin and long hoses connect miniature cylinders in this scheme.The motor drives the drag screw and thereby pushes the power-producing cylinder,which makes the pressure in the chamber of the actuating cylinder and its connecting hose increase until it moves.These constitute an asymmetric double cylinder drive.Both open loop and closed loop control systems are examined to decide a better system required.In order to obtain the desired steady and dynamic response,modeling and simulation are carried out,with the effects of the hose deformation taken into consideration.Results show that the hoses that connect miniature cylinders can prolong the response lag of the actuating cylinder and reduce the retract accuracy and the dynamic response.Developed from the absolutely symmetric double cylinder,the proposed asymmetric double cylinders with proper size ratio can improve the performance of the hydromechanical hybrid actuator but does not weaken its stability.