Hydraulic cylinders are divided into single-rod asymmetric cylinders and double-rod symmetric cylinders. The single-rod asymmetric cylinder has the advantages of small size and simple structure,but its speed characteristic is not symmetric. The double rod symmetric cylinder has the characteristic of symmetric speed,but it cannot be used in some special occasions. In this paper,one special hydraulic cylinder,a single-rod symmetric cylinder,is developed. Firstly,characters of this type of cylinder are introduced. Then,the system model is constructed by using one software which is Simulation X. Moreover,one single rod asymmetric cylinder is designed and the test rig using the symmetric valve to control single-rod symmetric or asymmetric cylinder is constructed. Both of the simulation and experimental results show that the symmetric valve control single-rod symmetric cylinder servo system is of symmetric speed characteristic,which can be used in practical occasion.

液压执行器运动轨迹容易受到多种环境因素干扰,导致实际运动轨迹偏离理论运动轨迹,造成定位精度下降。对此,建立了单杆液压执行器模型简图,采用李雅普诺夫稳定控制器控制液压执行器的运动轨迹。分析了双侧遥控操作系统的动态模型,推导了液压执行器流量非线性控制方程式,设计了单杆液压致动器双侧控制的李雅普诺夫稳定控制方案,采用数学方法对控制器的稳定性进行了证明。结合具体实例,对单杆液压执行器的运动轨迹跟踪误差进行仿真,并与传统PID控制器的跟踪误差形成对比。对误差的仿真结果表明:在受到外界波形干扰时,采用李雅普诺夫稳定控制器控制液压执行器运动轨迹,产生误差较小。液压执行器采用李雅普诺夫稳定控制器,能够提高系统运动的稳定性,降低运动轨迹产生的误差。