模锻液压机力偶调平系统建模和最优控制

Modeling and optimal control of couple leveling system for die forging hydraulic press

通过对200 MN模锻液压机力偶调平方式的分析,建立了其力偶调平系统的非线性模型。根据模型中存在的非线性和不确定扰动的结构特点,提出了线性二次型最优控制与反馈线性化方法相结合的双闭环控制策略,并设计了扰动估计器来抑制扰动的影响,实现液压缸的同步控制。仿真对比实验表明,该控制策略优于传统的双闭环PID控制,使调平系统获得更高的调节速度和精度,可使模具准确压合,提高锻件质量,降低废品率,为实际加工过程中的调平控制提供理论依据。

Through analyzing the couple leveling method for 200 MN die forging hydraulic press, the nonlinear mathematical model of couple leveling system for forging hydraulic press was established. A new control strategy using the combination of optimal control of linear quadratic type and feedback linearization method was presented based on the nonlinear and uncertain disturbance structure characteristic of model. And the disturbance estimator was designed to overcome the disturbance and realize synchronous control of hydraulic cylinder. Simulation results show that the proposed double-loop control strategy is better than the traditional proportional-integral-derivative control method with higher leveling speed and accuracy which can improve the quality of forging in order to lower rejection rate, and provide a theoretical basis for leveling control during the actual machining process.