液压双边滚切剪非线性系统稳定性分析

双边剪机械动力学与液压动力学的耦合作用以及上刀架与液压缸之间的位置反馈，都是系统不稳定的因素。在这个模型中，所有的不稳定因素都来自于液压油的控制。通过采用非对称阀控制非对称缸的方法建立液压系统的数学模型，得到了伺服液压缸压力、流量的非线性状态方程，并利用李雅普诺夫稳定性判据分析了四缸耦合的非线性系统的稳定性。通过采集现场实验数据表明：四缸运动轨迹可以较好地按照既定轨迹运动，验证了此方法可以满足现场的实际需求。

Analysis of Nonlinear System Stability of a Hydraulic Bilateral Rolling Shear

A hydraulic bilateral rolling shear is the composite connecting rod shearing mechanism with the upper blade driven by servo-cylinders. Because an interaction between the mechanical dynamics and hydraulic dynamics of the machine and the hydro-mechanical interaction has a positive feedback component, which produces instability phenomenon. In this model, all instabilities energy comes from the fuel. A hydraulic servo system model was established based on unsymmetrical valve controlling unsymmetrical cylinder and the nonlinear equation of the state between force and cylinder flow was proposed. Moreover, Lyapunov stability theory was used to analyze the stability of system. Based on field experiment data, actual trajectory agrees well with given trajectory, showing that this method can meet the practical demand in engineering.