变论域模糊PID控制微流挤出型3D打印机的挤压力研究

Research on extrusion force of micro-flow extrusion 3D printer controlled by variable universe fuzzy PID

为了提高微流挤出型3D打印机的打印精度,针对其挤压力控制在挤出成型过程中存在时变性和非线性等典型特性,基于挤压力模型分析打印材料的挤出成型过程,并提出了一种变论域模糊PID(proportion integration differentiation,比例积分微分)控制策略,以实现挤出成型过程中挤压力不规律变化时的快速调节功能。同时,利用MATLAB软件建立挤压力控制系统仿真模型以开展不同控制策略的仿真分析,并利用自主搭建的实验平台进行实物打印,以验证所提出控制策略的可行性。仿真和实验结果表明,变论域模糊PID控制策略对改善成型坯体表面质量和提高成型精度有显著效果。所提出的变论域模糊PID控制策略可为挤出型3D打印机挤压力的稳定控制提供一定参考,也可为类似时变和非线性控制系统提供一定的借鉴。

In order to improve the printing accuracy of micro-flow extrusion 3D printer, aiming at the typical characteristics of its extrusion force control, such as time-varying and nonlinear, the extrusion process of printing materials was analyzed based on the extrusion force model, and a variable universe fuzzy PID(proportion integration differentiation) control strategy was proposed to realize rapid adjustment when the extrusion force changed irregularly in the extrusion process. At the same time, the MATLAB software was used to establish the simulation model of extrusion force control system to carry out the simulation analysis of different control strategies, and the self-built experimental platform was used to print the real object to verify the feasibility of the proposed control strategy. The simulation and experimental results showed that the variable universe fuzzy PID control strategy had a significant effect on improving the surface quality of formed body and the forming accuracy. The proposed variable universe fuzzy PID control strategy can provide some reference for the stable control of extrusion force of extrusion 3D printer, and also can provide some reference for similar time-varying and nonlinear control systems.