复杂液压系统动态特性仿真中的刚性问题研究

针对复杂液压系统动态特性仿真中出现的刚性问题，从基本波压元件的建模入手研究了降低系统模型刚性问题的方法。基于里兹近似法，从分布参数模型出发得到了液压管路的精确近似的集中参数模型；引入了分段的阀口流量计算公式，解决了传统紊流流量方程存在奇点的问题；采用迭代计算、模型降阶和线性化处理的方法，避免了小液压容腔和小阀芯质量引入系统模型时带来的刚性问题。

Research on Stiff Problems in Dynamic Simulation of Complex Hydraulic System

Modeling problems of hydraulic components are discussed and methods to reduce the stiff problems in dynamic simulation of complex hydraulic system are studied. A lumped parameter model of fluid transmission line is given based on the accurate approximation method of distributed parameter model and Ritz approximation method is used. A sectional flow formula is given to avoid the infinite derivative of conventional orifice flow formula. Iterated method, reduced-order and linearized methods are introduced to solve the stiff problems caused by small volume and small mass of valve joined into system differential equations.