Fuzzy logic control strategy for submerged arc automatic welding of digital controlling

A microcomputer control system based on 80C320 and a switching regulation of wire feeder were designed. A correction factor based double model fuzzy logic controller (FLC) was introduced to achieve welding digital and intellectualized control by means of wire feeding speed feedback. The controller has many functions such as keyboard input, light emitting diode (LED) display and real-time intellectualized control of welding process etc. The controlling performance influenced by the coefficient of correction function was discussed. It was concluded by the experiments the relation between the coefftcient of correction function and welding quality, when the coefficient of correction function is great, the dynamic character of controller is better, when the coefficient of correction function is small, the sensitivity character of controller is better. Experimental results also show that digital and fuzzy logic control method enable the improvement of appearance of weld and stability of welding process to be achieved in submerged arc automatic welding.     

基于T-S模型和模糊神经网络的焊接电源群控

利用多台焊接电源同时对同一工件进行焊接，当外电压波动时，众焊接电源依靠自身控制系统进行各自调节的过程也是对外电网干扰的再生过程。将模糊理论与神经网络相结合，并应用于多焊接电源的群控。在分析和设计了状态变量的隶属度函数、推理规则、解模糊算法等基础上，完成了基于T—S（Tagaki—Sugeno）模型的自适应模糊神经推理控制器设计。利用该控制模型在Simulink搭建的焊接电源群控模型上进行仿真。结果表明，该控制模型具有调整时间短，超调量小的优点（与众焊接电源各自单独调节相比较，调整时间缩短了22％，超调量减小了40％），反映出良好的动态特性。     

Fuzzy neural networks for control of penetration depth during GTAW

0　ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｗｅｌｄｍｏｄｅｌｉｎｇａｎｄｃｏｎｔｒｏｌａｒｅｖｅｒｙｉｍｐｏｒｔａｎｔｔｏｔｈｅｍｅｃｈａｎｉｃｓｏｆｗｅｌｄｐｒｏｃｅｓｓａｎｄｈｏｗｔｈｅｙｃａｎｂｅｂｅｓｔｕｔｉｌｉｚｅｄ.Ｔｈｅｓａｔｉｓｆｉｅｄｃｏｎｔｒｏｌｏｆｔｈｅｏｖｅｒａｌｌｗｅｌｄｐｒｏｃｅｓｓｉｓｎｏｔｅａｓｉｌｙａｃｃｏｍｐｌｉｓｈｅｄ,ｌａｒｇｅｌｙｄｕｅｔｏｔｈｅｉｎａｄｅｑｕａｃｉｅｓｏｆｔｈｅａｖａｉｌａｂｌｅｐｒｏｃｅｓｓｍｏｄｅｌｓ.Ｔｈｅａｒｃｗｅｌｄｉｎｇｐｒｏｃｅｓｓｔ…     

Correction factor based double model fuzzy logic control strategy of arc voltage in pulsed MIG welding

0Introduction Improvedstabilityofweldingarclengthhasbecome increasinglyimportantforhigherweldingquality.Thesta bilityofweldingarclengthisdependentontwoaspects: oneistheintrinsicself adjustmentofarc,anotheristhe effectoftheweldingconditionparametersandthe…     

Design of a fuzzy logic approach based on genetic algorithms for robust plasma-sprayed zirconia depositions

This paper proposes a design for an adaptive system by modeling the relationship between coating surface roughnesses and the controling factors in plasma spray coating processes. A statistical design was used to obtain sufficient experimental information with the least number of experiments. Analysis of variance was then used to select significant control factors for reinforced coatings, and these identified factors used to construct an adaptive fuzzy logic control model. In order to model the process, a fuzzy logic controller (FLC) was utilized. A genetic algorithm (GA) was applied as a tool to optimize rule bases from traditional FLCs. Therefore, with the use of a GA-optimized FLC, robust reinforced deposition for coatings in the plasma spraying process can be obtained. The experimental results show that the obtained optimal rule base for FLC is capable of achieving the desired results. That is to say, the proposed design, which combines a statistical method and a GA-optimized FLC, is efficient and robust for the investigation of reinforced coatings in a plasma spraying process.     

CO2弧焊电流波形的多参数自寻优智能控制

研究并提出了一种CO2气体保护焊电流波形的多参数自寻优智能控制法,电流波形的模糊寻优计及弧焊过程特征参数的综合影响,并在表征短路过渡综合性能的特征综合值作为弧焊过程定量评价和目标实时寻优的函数。在波控参数基值的基础上,基于综合性能寻优过程采用三级模糊调节算法,对电流波形参数分步调节寻优。该法实际上将双输入三输出式的波控参数模糊控制系统化为多路,开关性的双输入单输出式的模糊控制,通过短路及燃弧初始阶段的电流波形控制参数的模糊自寻优,逐步使波控参数和焊接规范参数达到和谐匹配,以实现焊接过程熔滴的稳定可控过渡,改善焊接过程的综合性能。     

全数字机器人VPPA焊接电源

为提高铝合金机器人VPPA(变极性等离子弧)焊接过程的稳定性,研制了一台600 A级基于ARM(advanced RISC machines)的全数字机器人VPPA焊接电源.主电路采用双逆变拓扑结构,初级逆变电路采用全桥拓扑,次级逆变电路采用双半桥并联拓扑;以基于Cortex-M4内核的STM32F405RGT6 ARM微处理器为主控芯片,植入FreeRTOS嵌入式实时操作系统,设计了机器人VPPA焊接过程数字化控制系统;采用自适应模糊免疫PID控制算法实现电流闭环控制,获得了稳定的电流输出波形;设计了基于ARM的数字面板,实现了人机交互的数字化.结果表明,研制的机器人VPPA焊接电源动态调节性能优良,焊接过程稳定可靠,焊缝成形良好.     

智能化CO2焊机的自寻优控制器

基于熔滴过液过程性能的综合评判和一元化自寻优控制系统的程序协调模式,研究了智能化CO2焊机的一元化自寻优的模糊协调控制器。试验表明,该控制器及其自寻优协调模式能够反映CO2弧焊过程的本质,克服短路过渡频率或弧压等单指标作为寻优目标函数的不足,明显地改善焊接过程的综合性能。     

CO2焊接过程熔滴过渡频率的Fuzzy/PID控制

在单片机控制ＩＧＢＴ逆变电源的基础上,建立ＣＯ２焊接过程熔滴过渡频率的Ｆｕｚｚｙ／ＰＩＤ控制系统,并对其系统结构、控制原理和控制算法进行了描述。本系统通过调节波形参数从而改变燃弧时间来控制熔滴守渡的频率,当熔滴过渡频率的误差较大时,采用Ｆｕｚｚｙ控制方法,而在误差较小时采用控制方法。本系统还在Ｆｕｚｚｙ控制过程中引入了控制参数自学习功能,保证了不同焊接规范时控制系统的动态响应和静态精度。焊接试验表     

模糊控制技术在MIG焊熔宽控制系统中的应用

针对MIG焊焊缝熔宽无法建立起精确的数字模型,难以用常规控制技术进行控制,本文将模糊控制技术应用于MIG焊熔宽控制系统,给出熔宽模糊控制的系统结构图,详细介绍了熔宽模糊控制器的设计过程,得到模糊控制状态表。试验结果表明,该技术可实现对焊缝熔宽进行实时控制。     

基于遗传模糊PID的液压AGC控制系统研究

液压AGC系统是一个多变量、非线性、强耦合、时变的复杂控制系统,常规的控制方法很难达到较好的控制效果,而采用将现代控制方法和智能算法相结合的控制策略已经成为一种趋势。PID控制是被证实行之有效的控制方法,针对其3个参数不能自调整问题,提出了模糊PID控制策略;针对模糊控制存在人为确定隶属度且不能动态调整参数的弊端,提出了用改进的遗传算法进行参数寻优的办法。仿真结果表明:基于改进遗传算法的模糊PID控制器性能更优。     

基于Matlab-FIS的带极堆焊成形质量模糊综合评价

采用模糊层析分析法(FAHP),选取焊道厚度、宽度、边缘接触角、直线度四个指标拟建带极堆焊成形质量模糊综合评价模型;通过构造模糊一致判断矩阵,确定各级指标在评价中的权重系数;结合实际焊接经验,确定各指标的隶属度函数;以Matlab-FIS模糊推理系统为载体,从而实现模型的计算过程;设计试验对模型进行验证.结果表明,评价结果与实际观测结果相吻合,建立了一种带极堆焊成形质量综合评价的模型.     

MIG焊熔宽模糊控制系统

大双波长滤光片正面实时检测焊缝熔宽技术的基础上建立了焊缝熔宽模糊控制系统。本文对熔宽模糊控制器的结构以及模糊控制变量的选择进行了讨论,在此模糊控制系统中采用双输入单输出的模糊控制器模型,即采用迷惑宽的变化及其变化率作为模糊控制器的两输入量,采用焊接电流作为模糊控制器的输出量。本文给出了熔宽模糊控制系统结构图并详细介绍了熔宽模糊控制器的设计过程,根据用双波长滤光片正面实时检测焊缝熔宽技术得到的焊接电     

Tailored blank technology of high strength steel sheet

The third part of this series covers, first, the basic function of the conventional voltage controlled short circuiting MIG/MAG welding process (CCC) and the related power source static behaviour. Second, it deals with the mechanisms related to the dynamics of the transfer of the metal drop to the weld pool during short circuit welding. Third, a set of MIG/MAG stability concepts is set out, on which there is no unanimous agreement in current welding studies. Fourth, a proposal by the authors is included. Finally, it demonstrates how systems such as CCC operate and the scientific and technological experience gained by LABSOLDA in this process, from analogue control up to the most modern software controlled versions and the future of the process as part of the advanced control system.     

基于模糊自整定参数PID控制的铝合金薄板脉冲MIG焊

针对铝合金薄板脉冲MIG焊,提出了一种比例积分微分(proportion integral derivative,PID)参数模糊自整定控制方法,文中介绍了其原理及设计思路,将模糊逻辑控制器引入已建立的PID控制器的Simulink仿真模型,实现了PID参数模糊自调节,并进行了输入适应性对比试验和抗干扰试验分析,表明PID参数模糊自整定控制器在输入适应性和抗干扰方面更胜一筹,能进一步提高弧焊电源性能.最后对铝合金1 mm薄板进行了传统PID控制和模糊自整定参数PID控制焊接试验对比.结果表明,该方法焊缝光亮、飞溅少、焊接过程比较平稳,可获得较好的焊缝质量和稳定的焊接过程.     

基于专家系统高频焊接过程控制的研究

介绍了专家系统的原理及应用基础。在知识库的建立方面采用模糊隶属函数来对知识表示,且推理过程运用正向推理和模糊技术。在对高频焊接过程诸多参数分析后,提出了应用高级语言VisualBasic和数据库知识来实现对高频焊接过程的控制,从而实现高频焊接过程的自动化及智能化。     

基于温度控制系统的模糊自整定PID算法设计

考虑到温度的控制特性,以及常规PID控制器参数整定方法不能获得满意控制性能的问题,提出了一种基于模糊自整定参数的PID算法.针对隶属度函数对模糊推理模型的精度影响和控制算法的特点,建立了模糊PID控制参数规则调整表.该方法不仅具有模糊控制的动态性能好、上升时间快和超调小的特点,而且具有PID控制器的鲁捧性好、动态跟踪品质高和稳态精度高的特性.结合实际的温度控制系统,对水的三相点、沸点以及水温进行了测试与控制,得到了实际控制的温度教据.     

One-knob self-optimizing fuzzy control of CO_2 arc welding process

1　ＩＮＴＲＯＤＵＣＴＩＯＮＡｓｗｅｋｎｏｗ ,ｔｈｅＣＯ2 ａｒｃｗｅｌｄｉｎｇｈａｓｍａｎｙｗｅｌｄ ｉｎｇｖａｒｉａｂｌｅｓａｎｄａｄｊｕｓｔａｂｌｅｐａｒａｍｅｔｅｒｓ.Ｗｈｅｎｔｈｅｓｅｖａｒｉａｂｌｅｓａｎｄｐａｒａｍｅｔｅｒｓｃａｎｎｏｔｂｅｃｏｏ     

智能短路过渡二氧化碳气体保护电弧焊数字控制系统

针对目前通用二氧化碳弧焊机在短路过渡区间焊接时存在的问题,基于DSP和MCU的全数字控制系统平台,从数字控制角度出发,引入分级递阶智能控制理论,设计并实现了二氧化碳气体保护电弧焊分级递阶智能全数字控制系统.该系统按照组织级、协调级和执行级进行构建,有机地将专家系统、模糊控制、数字PI控制器结合起来.试验结果表明,设计的智能短路过渡二氧化碳气体保护电弧焊数字控制系统取得较为理想的波形控制效果,实现了焊接过程控制的智能化,全面提升了二氧化碳气体保护电弧焊机的性能.     

A fuzzy-nets in-process (FNIP) system for tool-breakage monitoring in end-milling operations

The fuzzy-nets in-process (FNIP) system is proposed for monitoring tool breakage in end-milling operations. The FNIP system consists of two components: (1) the fuzzy search classifier (FSQ, which maps a state vector into a recommended action using fuzzy pattern recognition; and (2) the fuzzy adaptive controller (FAQ, which maps a state vector and a failure signal into a scalar grade that indicates state integrity. The FAC also produces the output action value, p, to upgrade FSC mapping according to the variation of the input state. By coupling fuzzy logic control systems and neural networks into the fuzzy-nets system, a self-learning capability (ability to generate rule bases and to fine-tune the membership functions of each linguist variable to the appropriate level of granularity) was developed. With this on-line learning capability, the fuzzy rule bases of FSC and FAC are established by fine-tuning the parameters in the FNIP system. After establishing all the fuzzy rule bases, the performance of the FNIP system is examined for an end-milling operation. Experiments have shown that the FNIP system is able to detect tool breakage in the end-milling operation “on-line”, approaching a real-time basis.