316LVM不銹鋼電阻點(diǎn)焊信息檢測(cè)分析及質(zhì)量實(shí)時(shí)控制研究
發(fā)布時(shí)間：2018-10-10 14:30
【摘要】：電阻點(diǎn)焊過程由于其形核時(shí)間極短且伴隨大量不確定因素的存在,具有高度非線性、多變量耦合并處于封閉狀態(tài)無法觀測(cè)、焊接特征信號(hào)提取困難等特點(diǎn),其質(zhì)量實(shí)時(shí)控制是長(zhǎng)期存在的難題。本文以醫(yī)學(xué)植入用316LVM不銹鋼的點(diǎn)焊過程為研究對(duì)象,通過對(duì)不同影響因素條件下的多種過程信息進(jìn)行分析,探討適應(yīng)面更廣的電阻點(diǎn)焊電極位移質(zhì)量控制新方法。加熱因素和機(jī)械因素是影響電極位移的兩大主要因素,其中機(jī)械因素包括施加的焊接壓力和工件約束條件。然而,傳統(tǒng)的電極位移控制方法沒有考慮機(jī)械因素的影響,在實(shí)際應(yīng)用中受到較大制約。針對(duì)該情況,本文首先基于伺服電機(jī)及DSP控制,設(shè)計(jì)了電阻點(diǎn)焊伺服加壓系統(tǒng)。通過機(jī)構(gòu)分析與優(yōu)化、系統(tǒng)參數(shù)分析與建模、合理的控制方式等,實(shí)現(xiàn)了電極快速下壓、柔性接觸和壓力的快速穩(wěn)定控制。針對(duì)機(jī)械約束條件變化下的電極位移控制,本文設(shè)計(jì)了焊接電流、電極間電壓、焊接壓力和電極位移等電阻點(diǎn)焊多信息檢測(cè)系統(tǒng),系統(tǒng)地測(cè)試了不同影響因素下的過程信息,探討了基于動(dòng)態(tài)信息識(shí)別機(jī)械約束條件的可行性和方法。結(jié)果表明,在小邊距、工件翹曲等主要機(jī)械影響因素存在時(shí),電極間電壓、動(dòng)態(tài)電阻和電極位移的綜合信息具有可區(qū)分的特征,通過對(duì)這些信息的深入分析研究,本文提出了小邊距和工件翹曲的識(shí)別方法,獲得了小邊距焊接的信息特征和規(guī)律。在此基礎(chǔ)上,提出了基于電極間電壓和電極位移信息的點(diǎn)焊質(zhì)量實(shí)時(shí)控制方法。該方法利用電極間電壓和位移信息對(duì)工件的機(jī)械約束變化進(jìn)行在線辨識(shí),在實(shí)際控制中通過跟蹤相應(yīng)機(jī)械約束條件下的標(biāo)準(zhǔn)位移對(duì)焊接過程進(jìn)行控制�；赟-Function以及NARX神經(jīng)網(wǎng)絡(luò)算法,利用Simulink建立模型進(jìn)行模擬仿真。結(jié)果表明,對(duì)于熱影響因素以及機(jī)械影響因素,此控制方式能夠使輸出電極位移合理跟蹤相應(yīng)的參考位移,有效提高焊接質(zhì)量。
[Abstract]:Because of the short nucleation time and the existence of a large number of uncertain factors, the resistance spot welding process is highly nonlinear, multivariable coupled and can not be observed in a closed state, and it is difficult to extract the welding characteristic signals. Real-time quality control is a difficult problem for a long time. In this paper, the spot welding process of 316LVM stainless steel for medical implantation is taken as the research object. Through the analysis of various process information under different influencing factors, a new method of displacement quality control of resistance spot welding electrode with wider adaptive surface is discussed. Heating factor and mechanical factor are two main factors which affect electrode displacement. Mechanical factors include welding pressure applied and constraint condition of workpiece. However, the traditional electrode displacement control method does not consider the influence of mechanical factors, so it is restricted in practical application. Aiming at this situation, this paper first designs the resistance spot welding servo pressurization system based on servo motor and DSP control. By means of mechanism analysis and optimization, system parameter analysis and modeling, and reasonable control methods, the rapid and stable control of electrode pressure, flexible contact and pressure is realized. Aiming at the control of electrode displacement under the change of mechanical constraint condition, this paper designs a multi-information detecting system for resistance spot welding, such as welding current, voltage between electrodes, welding pressure and electrode displacement, and systematically tests the process information under different influence factors. The feasibility and method of identifying mechanical constraints based on dynamic information are discussed. The results show that the comprehensive information of interelectrode voltage, dynamic resistance and electrode displacement can be distinguished when the main mechanical factors such as small margin and warpage of workpiece exist. In this paper, a method of identifying small edge distance and workpiece warpage is proposed, and the information characteristics and rules of small edge distance welding are obtained. On this basis, a real-time control method of spot welding quality based on the information of voltage and displacement between electrodes is proposed. Based on the information of voltage and displacement between electrodes, the mechanical constraints of workpiece are identified online, and the welding process is controlled by tracking the standard displacement under the corresponding mechanical constraints in the actual control. Based on S-Function and NARX neural network algorithm, Simulink is used to build a model for simulation. The results show that the control method can make the displacement of the output electrode track the reference displacement reasonably and improve the welding quality effectively for the thermal and mechanical factors.
【學(xué)位授予單位】：華南理工大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2016
【分類號(hào)】：TG409
本文編號(hào)：2262137
[Abstract]:Because of the short nucleation time and the existence of a large number of uncertain factors, the resistance spot welding process is highly nonlinear, multivariable coupled and can not be observed in a closed state, and it is difficult to extract the welding characteristic signals. Real-time quality control is a difficult problem for a long time. In this paper, the spot welding process of 316LVM stainless steel for medical implantation is taken as the research object. Through the analysis of various process information under different influencing factors, a new method of displacement quality control of resistance spot welding electrode with wider adaptive surface is discussed. Heating factor and mechanical factor are two main factors which affect electrode displacement. Mechanical factors include welding pressure applied and constraint condition of workpiece. However, the traditional electrode displacement control method does not consider the influence of mechanical factors, so it is restricted in practical application. Aiming at this situation, this paper first designs the resistance spot welding servo pressurization system based on servo motor and DSP control. By means of mechanism analysis and optimization, system parameter analysis and modeling, and reasonable control methods, the rapid and stable control of electrode pressure, flexible contact and pressure is realized. Aiming at the control of electrode displacement under the change of mechanical constraint condition, this paper designs a multi-information detecting system for resistance spot welding, such as welding current, voltage between electrodes, welding pressure and electrode displacement, and systematically tests the process information under different influence factors. The feasibility and method of identifying mechanical constraints based on dynamic information are discussed. The results show that the comprehensive information of interelectrode voltage, dynamic resistance and electrode displacement can be distinguished when the main mechanical factors such as small margin and warpage of workpiece exist. In this paper, a method of identifying small edge distance and workpiece warpage is proposed, and the information characteristics and rules of small edge distance welding are obtained. On this basis, a real-time control method of spot welding quality based on the information of voltage and displacement between electrodes is proposed. Based on the information of voltage and displacement between electrodes, the mechanical constraints of workpiece are identified online, and the welding process is controlled by tracking the standard displacement under the corresponding mechanical constraints in the actual control. Based on S-Function and NARX neural network algorithm, Simulink is used to build a model for simulation. The results show that the control method can make the displacement of the output electrode track the reference displacement reasonably and improve the welding quality effectively for the thermal and mechanical factors.
【學(xué)位授予單位】：華南理工大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2016
【分類號(hào)】：TG409
【參考文獻(xiàn)】
相關(guān)期刊論文 前3條
1 史建濤,馬躍洲,陳劍虹;基于電極位移信號(hào)的電阻點(diǎn)焊質(zhì)量預(yù)測(cè)模型[J];電焊機(jī);2005年02期
2 申?duì)T,王士敏,羅承沐;一種電子式電流互感器的研制[J];電力系統(tǒng)自動(dòng)化;2002年18期
3 陳思;巴特沃斯低通濾波器的簡(jiǎn)化快速設(shè)計(jì)[J];信陽師范學(xué)院學(xué)報(bào)(自然科學(xué)版);1997年03期
，本文編號(hào)：2262137
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