抗偏载静压卧式伺服缸同步控制系统仿真研究

Simulation Research on Synchronous Control System of Anti Eccentric Load Static Pressure Horizontal Servo Cylinde

针对非对称静压支承抗偏载卧式重载伺服缸结构,在定压供油的情况下,为实现对上、下油垫油膜厚度的控制,通过建立该结构伺服缸的流量连续性方程以及活塞杆动力学方程,推导出上、下油膜厚度的传递函数,设计了位置伺服同步控制系统,并且对该控制系统存在的耦合关系进行了解耦运算,运用李雅普诺夫第二法进行了稳定性分析。利用MATLAB/Simulink搭建控制系统仿真模型,分别给系统输入正弦、阶跃、随机3种负载信号进行仿真,结果表明:在随机信号干扰下,控制系统同步性能最快,稳定性最好。验证了该控制系统的可靠性与稳定性,实现了对油膜厚度的精准控制,保证了伺服缸在运行过程中,活塞杆时刻对中,改善了伺服缸的密封性能,克服了偏载造成的不利影响。

In order to control the oil film thickness on the upper and lower oil cushions of asymmetric hydrostatic bearing anti-eccentric load horizontal heavy-duty servo cylinder under the condition of constant pressure oil supply,the transfer function of the oil film thickness on the upper and lower oil cushions was deduced by establishing the flow continuity equation of the servo cylinder and the dynamic equation of the piston rod.The position servo synchronous control system was designed,the coupling relationship of the control system was decoupled,and the stability was analyzed by the second method of Lyapunov.The simulation model of the control system was built through MATLAB/Simulink,and the system was simulated by inputting sinusoidal,step and random load signals.The results show that the control system has the fastest synchronization performance and the best reliability and stability under the interference of random signals,which can realize the precise control of the oil film thickness,ensures that the piston rod is aligned at all times during the operation of the servo cylinder,improve the sealing performance of the servo cylinder,and overcome the adverse effect caused by the unbalanced load.