本文關(guān)鍵詞： 移動焊接機器人 焊縫識別 軌跡規(guī)劃 跟蹤控制 滑模變結(jié)構(gòu)控制　出處：《南京理工大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：隨著工業(yè)4.0的提出和《中國制造2025》的頒布,我國工業(yè)生產(chǎn)朝著自動化,智能化、信息化方向發(fā)展已經(jīng)成為必然的趨勢。焊接機器人融合了識別、焊接、控制等眾多技術(shù),反應(yīng)了一個國家的科技水平。本文以移動焊接機器人為研究對象,主要研究了焊縫識別算法、移動焊接機器人運動學(xué)與動力學(xué)模型、軌跡規(guī)劃和跟蹤控制的方法。1焊縫識別算法采用中值濾波和均值濾波算法對焊縫及周邊的圖像進行處理,削弱干擾,并采用Sobel邊緣檢測算法提取焊縫的邊緣曲線,從而達(dá)到焊縫識別的目的。2運動學(xué)與動力學(xué)模型首先分析了移動平臺的非完整性,并采用奇次變換的方法建立移動平臺的運動模型。然后采用Denavit-Hartenberg建模方法建立了機械臂的運動學(xué)模型。然后結(jié)合移動平臺和機械臂的運動模型建立了焊接機器人的運動學(xué)模型,最后采用拉格朗日力學(xué)法建立了移動焊接機器人的動力學(xué)方程。3軌跡規(guī)劃首先假設(shè)移動平臺做直線運動,研究了機械臂的軌跡規(guī)劃問題。采用梯度下降法與二分法結(jié)合的算法對機械臂的關(guān)節(jié)軌跡進行優(yōu)化,并通過仿真驗證了算法的有效性。然后針對大曲度焊縫,研究了移動平臺和機械臂的同步規(guī)劃問題。針對同步規(guī)劃問題,首先研究了機械臂末端位置點到點的規(guī)劃問題,通過分析機械臂末端點到點的運動特點總結(jié)出規(guī)劃任務(wù)的實質(zhì)是選擇移動平臺運動所圍繞圓心的位置,并采用基于梯度下降法與二分法結(jié)合的優(yōu)化算法對移動平臺輪子和機械臂的關(guān)節(jié)運動進行了規(guī)劃,仿真結(jié)果顯示機械臂的末端較好的跟蹤離散化后焊縫軌跡上的點。然后研究了機械臂末端的速度規(guī)劃問題,采用遺傳算法規(guī)劃移動平臺左右輪的角速度和機械臂的關(guān)節(jié)速度曲線,使得機械臂的末端速度方向與焊縫的切線方向保持一致,從而實現(xiàn)機械臂末端跟蹤焊縫軌跡。通過仿真驗證規(guī)劃方法的有效性。4基于滑模變結(jié)構(gòu)控制的移動焊接機器人控制器研究首先設(shè)計了移動焊接機器人的線性滑模切換面。然后在移動焊接機器人的動力學(xué)方程的基礎(chǔ)上設(shè)計了基于指數(shù)趨近律的控制律,并采用飽和函數(shù)削弱滑模變結(jié)構(gòu)控制的抖振。最后采用S函數(shù)在Simulink中搭建了滑�？刂破骱鸵苿雍附訖C器人的動力學(xué)模型。通過仿真驗證了滑�？刂破鞯挠行�,不僅削弱了抖振現(xiàn)象,而且提高了系統(tǒng)的魯棒性和軌跡跟蹤的效果。
[Abstract]:With the introduction of industry 4.0 and the promulgation of "made in China 2025", the development of China's industrial production towards automation, intelligence and information has become an inevitable trend. Welding robot fusion recognition. Welding, control and many other technologies reflect the scientific and technological level of a country. In this paper, the mobile welding robot as the research object, mainly studied the weld identification algorithm, kinematics and dynamics model of mobile welding robot. Methods of trajectory Planning and tracking Control. 1. The median filter and mean filter algorithm are used to process the images of the weld seam and its periphery, so as to reduce the interference. The Sobel edge detection algorithm is used to extract the edge curve of the weld seam. 2. The kinematics and dynamics model is used to analyze the non-integrity of the mobile platform. The motion model of mobile platform is established by odd degree transformation, and then the kinematics model of manipulator is established by using Denavit-Hartenberg modeling method. The kinematics model of welding robot is established. Finally, the dynamic equation .3 trajectory planning of mobile welding robot is established by using Lagrange mechanics method. Firstly, the linear motion of mobile platform is assumed. The trajectory planning problem of the manipulator is studied. The joint trajectory of the manipulator is optimized by using gradient descent method and dichotomy, and the effectiveness of the algorithm is verified by simulation. The synchronization planning problem of mobile platform and manipulator is studied. Aiming at the synchronization planning problem, the point to point planning of the end of the manipulator is first studied. By analyzing the motion characteristics of the end point to point of the manipulator, it is concluded that the essence of the planning task is to select the position around the center of the motion of the mobile platform. An optimization algorithm based on gradient descent and dichotomy is used to plan the joint motion of the wheel and manipulator of the mobile platform. The simulation results show that the end of the manipulator can track the points on the weld trajectory after discretization. Then the velocity planning problem of the end of the manipulator is studied. Genetic algorithm is used to plan the angular velocity of the left and right wheels of the mobile platform and the joint velocity curve of the manipulator, so that the direction of the end velocity of the manipulator is consistent with the tangent direction of the weld. The effectiveness of the planning method is verified by simulation. 4. The research of mobile welding robot controller based on sliding mode variable structure control. Firstly, the linear slip of mobile welding robot is designed. Then the control law based on exponential approach law is designed based on the dynamic equation of mobile welding robot. Finally, the dynamic models of sliding mode controller and mobile welding robot are built by S function in Simulink. The sliding mode control is verified by simulation. The effectiveness of the machine. Not only the chattering phenomenon is weakened, but also the robustness of the system and the effect of trajectory tracking are improved.
【學(xué)位授予單位】：南京理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TP242

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