铣削机器人加工误差建模及实验研究

发布时间：2018-07-13 12:48

【摘要】：目前,工厂多使用大型数控加工中心进行超大构件整体式加工,存在成本高、改造难、利用率低等问题。而铣削加工机器人具有工作范围大、成本低和可扩展性强的优势,可以解决上述大构件整体式加工难题。但相比于数控机床,铣削加工机器人低精度和低刚度的劣势限制了其在金属切削领域的进一步应用,针对该问题,本文在机器人运动学基础上定位误差模型,通过实验辨识误差模型相关参数,制定机器人定位误差补偿方案和机器人铣削加工方案降低加工误差。本文首先对机器人运动学理论进行研究。分析IRB 2400型工业机器人结构,建立了D-H运动学模型,详细推导了机器人正逆运动学公式和雅克比矩阵,并测试机器人主要性能指标。之后,建立了铣削机器人加工误差模型并辨识了模型参数。从稳态加工角度分析了机器人加工误差影响因素,建立铣削力模型并进行受力分析。机器人定位误差作为加工误差的主要影响因素,本文在机器人微分变换基础上建立机器人加工误差模型,包括几何误差模型和关节误差模型,并通过辨识实验完善误差模型,提出了机器人几何误差补偿方案。最后,提出了机器人铣削加工方案,设计了铣削加工实验。根据误差模型及相关实验分析,提出了机器人铣削加工策略和加工对刀方案。根据机器人模态分析研究选定主轴转速,通过铣削力测量实验验证铣削力模型。对各切削参数对工件表面粗糙度的影响进行了实验探讨。通过铣削加工验证实验证明了机器人铣削加工策略和对刀方案可以降低加工误差。
[Abstract]:At present, large NC machining centers are often used for large component integral machining in factories, which have the problems of high cost, difficult transformation and low utilization ratio. However, the milling robot has the advantages of large working range, low cost and strong expansibility, so it can solve the problem of monolithic machining of the large components mentioned above. However, compared with numerical control machine tools, the disadvantages of low precision and low stiffness of milling robot limit its further application in the field of metal cutting. In view of this problem, the positioning error model based on robot kinematics is proposed in this paper. Through the experimental identification of the parameters of the error model, the robot positioning error compensation scheme and the robot milling scheme are developed to reduce the machining error. Firstly, the kinematics theory of robot is studied in this paper. The structure of IRB 2400 industrial robot is analyzed, the D-H kinematics model is established, the forward and inverse kinematics formula and Jacobian matrix of the robot are derived in detail, and the main performance indexes of the robot are tested. Then, the machining error model of milling robot is established and the model parameters are identified. From the point of view of steady-state machining, the influencing factors of robot machining error are analyzed, and the milling force model is established and the force is analyzed. Robot positioning error is the main influencing factor of machining error. In this paper, the robot machining error model, including geometric error model and joint error model, is established on the basis of robot differential transformation, and the error model is improved by identification experiment. A scheme of geometric error compensation for robot is proposed. Finally, the scheme of robot milling is put forward, and the milling experiment is designed. According to the error model and related experimental analysis, the milling strategy and cutter alignment scheme of robot are put forward. According to the modal analysis of the robot, the spindle speed is selected and the milling force model is verified by the milling force measurement experiment. The influence of cutting parameters on the surface roughness of workpiece is discussed experimentally. The experimental results show that the robot milling strategy and cutter alignment scheme can reduce the machining error.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG547
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本文编号：2119419