【作者】 甘才军；

【导师】 齐乐华；

【作者基本信息】 西北工业大学 ， 机械电子工程， 2004， 硕士

【摘要】 液态浸渗挤压(简称液-固挤压)复合材料工艺是近年来开发出的一种复合材料成形新工艺。这种工艺能以较低的成本制备出性能优良的复合材料管、棒材，从而具有广阔的应用前景。通过大量实验，已掌握了关键工艺参数(熔液浇注温度、挤压模预热温度、浸渍时间、浸渍力)的优化选取方法。在合理选取关键工艺参数的前提下，挤压速度的控制是成形出质量良好制件的关键。但是，目前对于挤压速度的控制仍停留在手动控制阶段，利用该工艺制备管、棒材制件的成功与否受操作者对该工艺及其设备的经验及熟练程度等不确定因素影响很大。针对这一问题，本文研究了现有条件下工艺过程挤压速度的自动控制问题，并为此设计了一套计算机控制系统。 复合材料液-固挤压工艺过程中挤压速度的控制问题，不仅涉及到成形设备，而且与工艺本身的特点密切相关。因此，本文从挤压速度的控制出发，首先探讨并确立了本系统的基本控制策略；然后根据此控制策略的必然要求，对该工艺挤压过程所涉及到的挤压力、温度、挤压轴位移等参数间的关系进行了深入研究，利用系统辨识方法建立了挤压过程关键阶段的数学模型；在此基础上完成了相应的控制器设计，给出了控制算法，并对所设计的控制系统进行了仿真。仿真结果表明该控制系统是稳定的，系统性能可满足工艺要求，由此证明了它的可行性与有效性。 最后，利用模块化设计方法完成了控制系统硬件的选型与设计，并编制了交互性良好的过程控制软件，从而使该控制系统得以初步实现。 上述工作的完成，初步解决了挤压速度的自动控制问题，为复合材料液-固挤压成形工艺的实际应用奠定了基础。更多还原

【Abstract】 Liquid-solid extrusion of composite material is a new kind of metal forming process, which has been developed in recent years with a promising practical application prospect for its simple working procedure, low cost and good workpiece performance.Through a lot of experiments,The optimization and chosing method of key process parameters(pouring temperature, mold warm-up temperature, impregnating pressure, impregnating time)has been mastered.Under the precondition of appropriate chosing these parameters, the effective control of extrusion velocity is the key of mading good workpiece.But the control of extrusion velocity remains a handwork,and it is heavily affected by such uncertainties as a handler’s knowledge and skill about the process.In order to solve the problem, the automatic control of the extrusion velocity is studied,and a computer control system is also designed under existing condition.The control of extrusion velocity in the process is not only involved in the process equipment,but also related to the process itself. So,in the paper,proceeding from the automatic control of extrusion velocity and based on the basic control strategy presented firstly,the relation among parameters of the process such as pressure,temperature and displacement is investigated,and the model of the process has been built using system identification method.Then, a corresponding controller is designed together with its control algorithm,and the control system is proved viable and effective by the results of simulation on the control system.In the end,the problem of the realization of the control system is discussed by using modularization method.The hardware of the control system is designed and a sofeware with a perfect manmachine interface is developed,too.Thus, the problem of the control of extrusion velocity during the process has been basically solved, which establishes a base for the application of the process.更多还原