实验用微弧氧化智能系统研制

发布时间：2018-04-05 07:34

本文选题：微弧氧化　切入点：DSP　出处：《太原理工大学》2017年硕士论文

【摘要】：微弧氧化是一种能提高Al、Mg、Ti等金属及其合金表面耐腐蚀性能、耐磨损性能的表面处理方法。其工艺流程简单、环境污染小、对材料的适应性宽,广泛应用于航空、航天、化工、电子、医疗等领域。在微弧氧化过程中,电源参数的变化将对膜层的生长和形态产生影响,是成膜质量的关键因素。目前,微弧氧化电源主要存在恒压或恒流两种模式,往往需要提前预设,在微弧氧化过程中固定不变,不利于研究微弧氧化过程中变化电参数对成膜的影响。因此,为了对微弧氧化过程的电参量进行实时控制,拟在实验室中设计一种通过在线编程控制电源输出、能对一定条件下膜层性能进行预测的微弧氧化智能系统。在分析微弧氧化系统特点的基础上,构建整体结构和设计各功能模块。微弧氧化智能系统按功能划分为电解槽、冷却模块、搅拌模块、温度监测系统及电源监测与控制系统。其中,电源监测与控制系统的设计是最主要的部分,包含硬件设计和软件设计。硬件设计包括主电路设计和控制系统电路设计。电源主电路工作过程为整流-逆变-升压-整流-斩波。控制系统电路以数字信号处理器(DSP,本文采用TMS320F28335)作为控制芯片。DSP与UC3846配合驱动逆变电路、与2SD315A集成驱动模块配合驱动斩波电路。通过A/D模块对电压、电流和温度等模拟量信号进行采集。软件设计涉及DSP嵌入式程序设计和上位机的人机接口界面设计。DSP嵌入式程序主要是完成数据的处理,通过对采集到的电压、电流信号,按设计的PID算法对其进行处理,实现对输出信号的闭环控制。上位机完成对电压与电流数字或波形显示、对电源控制参数进行在线设置和通过BP神经网络对氧化膜层性能进行预测。使用自制微弧氧化系统,通过程序设定电源分阶段输出占空比不同的脉冲,分析该条件下对TC4合金氧化膜耐蚀性的影响。采用MATLAB设计BP神经网络模型,通过对实验样本进行训练和检验,证明此模型对微弧氧化层的耐蚀性能有一定的预测能力。本系统可以程序或实时控制电源参数,方便对微弧氧化过程进行过程监控,为实验室研究微弧氧化提供设备保障。
[Abstract]:Micro-arc oxidation is a surface treatment method which can improve the corrosion resistance and wear resistance of Al _ 2O _ 3 / mg _ (Ti) and its alloys.Its process is simple, environmental pollution is small, adaptability to materials is wide, widely used in aviation, aerospace, chemical, electronic, medical and other fields.In the process of micro-arc oxidation, the change of power supply parameters will affect the growth and morphology of the film, which is the key factor of film forming quality.At present, there are two main modes of micro-arc oxidation power supply: constant voltage or constant current, which often need to be preset in advance and fixed in the process of micro-arc oxidation, which is not conducive to the study of the influence of electric parameters on film formation during the process of micro-arc oxidation.Therefore, in order to control the electrical parameters in the process of micro-arc oxidation in real time, an intelligent micro-arc oxidation system is designed in the laboratory, which can control the output of the power supply by on-line programming and can predict the performance of the film under certain conditions.On the basis of analyzing the characteristics of microarc oxidation system, the whole structure and the design of each functional module are constructed.The intelligent system of micro-arc oxidation is divided into electrolysis cell, cooling module, mixing module, temperature monitoring system and power monitoring and control system according to its function.Among them, the design of power monitoring and control system is the most important part, including hardware design and software design.Hardware design includes main circuit design and control system circuit design.The main circuit of power supply works as rectifier-inverter-boost-rectifier-chopper.Digital signal processor (DSP) is used in the control system. TMS320F28335 (TMS320F28335) is used as the control chip. DSP works with UC3846 to drive inverter, and 2SD315A integrated driver module drives chopper circuit.The analog signals such as voltage, current and temperature are collected by A / D module.The software design involves the embedded program design of DSP and the interface design of man-machine interface of host computer. The embedded program of DSP is mainly to complete the data processing. The voltage and current signals collected are processed according to the designed PID algorithm.The closed-loop control of the output signal is realized.The upper computer displays the voltage and current digital or waveform, sets the control parameters of the power supply online and predicts the performance of the oxide film by BP neural network.By using a self-made micro-arc oxidation system, the effect of different pulse duty ratio on the corrosion resistance of TC4 alloy oxide film was analyzed.BP neural network model was designed by MATLAB. By training and testing the experimental samples, it is proved that the model has certain predictive ability to the corrosion resistance of micro-arc oxidation layer.The system can control the parameters of power supply in program or in real time, which can monitor the process of micro-arc oxidation and provide equipment guarantee for laboratory research on micro-arc oxidation.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG173

【相似文献】