张力控制技术在造纸与印刷设备运行中显得十分重要.针对非线性的张力控制对象,采用一般的滑模变结构控制方法难以避免系统抖振问题,使得目标跟踪精度存在较大误差.通过分析卷纸张力的动态卷绕特性,建立了收卷张力数学模型,并在滑模控制中引入模糊逻辑;采用模糊系统实现模型未知部分的自适应逼近,可有效降低模糊增益,从而消除抖振.以二轴张力控制系统为研究对象进行仿真分析,结果表明系统可以快速准确地跟踪阶跃与正弦信号,并能有效抑制简单滑模控制的抖振问题.为验证该控制系统的可行性,搭建了基于运动控制器的同步伺服试验台,实验结果表明系统在0.25 s以内达到稳定状态,纸卷张力能稳定地进行目标跟随,且只在较小的范围内波动,验证了控制策略的有效性.%Tension control technology is very important in the operation of papermaking and printing equipment. In view of the nonlinear tension control system with sliding mode, variable structure control is difficult to avoid chattering problem that could result in big error of tracking precision. The characteristics of this control strategy are to force system vibration with low amplitude and high frequency along the specified state trajectory. The sliding mode can be designed and the parameters of the system are independent of the disturbance. But in practical application, the sliding mode control has the phenomenon of high frequency chattering and long transition time. Tension mathematical model is established by analyzing the dynamic characteristics of tension. The fuzzy logic is introduced to achieve the a-daptive approximation of the unknown part of the model in order to eliminate the chattering and reduce the fuzzy gain effectively. The biaxial tension control system is selected as the research object in the simulation analysis. The results show that the system can rapidly and accurately track the step and sinusoidal signal, and can effectively restrain the chattering of sliding mode control problem. To validating the feasibility of the system, an experimental platform of tension control based on motion controller was built. The experimental results show that the system reaches steady state within 2.5 s, and the tension of scroll can track stably and fluctuate within small rang. The effectiveness of the control strategy which can provide reference for the actual tension control method can be verified.
展开▼
