中文摘要：

为了提高注塑机注射压力控制精度,根据伺服电动机直接驱动定量液压泵节能型注塑机的特点,建立注射液压系统注射压力的非线性数学模型,提出一种基于非线性二次曲线的模糊控制方法.采用基于压力差控制流量的方法引入一个非线性函数来优化流量信号,该方法无需专门设计速度控制向压力控制切换的切换点.由于液压系统本身的参数和负载模型参数均具有不确定性,采用模糊控制方法在线调节该非线性函数的参数.配合PI控制算法实现对注射压力的精确跟踪控制.仿真和实验结果表明,该方法能够满足注塑机实际工作时对注射压力的控制要求,稳态压力波动小于0.1MPa,具有良好的跟踪性能.

英文摘要：

According to the specialty of injection molding machine with servo motor and constant pump,a nonlinear dynamic model of injection hydraulic system was set up.Based on a nonlinear conic,a new type closed-loop pressure control was proposed to improve the control precision of injection pressure.A method of flow control was presented to create a nonlinear function with the help of the difference of pressure,and a fuzzy control method is used to adjust controller parameter on line to overcome uncertainties of parametric and load of hydraulic system,by which the flow signal was optimized,and the design of the point where the velocity control is switched to pressure control could be avoided.A PI control is combined to realize pressure tracking.The experimental and simulating results show that the proposed method can satisfy the requirement for injection pressure of injection molding machine and has good self-adapting character.The steady state pressure fluctuation is less than 0.1 MPa,which verifies the effective of this method.