六自由度关节型机器人参数标定方法与实验研究

发布时间：2018-01-28 06:04

本文关键词： 六自由度关节型机器人静态位姿精度机器人标定几何参数机器人刚度最小二乘算法蒙特卡罗方法　出处：《华中科技大学》2013年博士论文　论文类型：学位论文

【摘要】：随着生产力的提高和科学技术的迅速发展,制造业对六自由度关节型工业机器人自动化柔性生产的性能要求越来越高,研发和建立具有自主知识产权的工业机器人关键参数标定与实验方法,已成为国内主要行业对制造装备的基本需求。本文以六自由度关节型机器人对研究对象,以提升其静态位姿精度性能为目标,系统的对机器人参数标定方法和实验原理进行了研究。从机器人位姿精度的评估与测量方法出发,根据对机器人末端执行器位姿误差来源的分析,分别建立机器人运动学误差模型和刚度模型,并对机器人几何参数和非几何参数对位姿精度的影响进行建模和仿真。同时,基于参数优化求解方法,搭建机器人关键参数误差辨识的实验平台,对机器人末端执行器位姿误差进行补偿。根据企业需求并以机器人标定的实验原理为基础,搭建工业机器人性能检测的实验平台,为自主研发六自由度关节型机器人的性能检测提供有效的测量和评估手段。主要内容如下：首先,根据工业机器人标定方法和原理,对六自由度关节型机器人静态位姿精度的评估和测量方法进行描述与分析。针对国际标准ISO9283中对位姿精度的检测规范和要求,采用激光跟踪测量系统搭建位姿精度检测实验平台。同时,设计了一款用于位姿精度柔性测量的末端执行器,补充了标准内提供的检测手段,并通过蒙特卡罗方法对其测量精度进行了误差的数值分析与仿真。针对六自由度关节型机器人运动学特性,分别建立了机器人修正D-H参数(MD-H)和指数积(POE)运动学误差模型。以企业自主研发15kg喷涂机器人为测量对象,采用激光跟踪测量系统对机器人几何参数标定实验平台进行搭建。通过迭代最小二乘优化求解方法对几何参数误差进行辨识与补偿,并对机器人标定前后位姿性能进行分析与评估。针对六自由度关节型机器人柔顺特性,对机器人刚度模型进行分析,并以刚体运动学和基于关节柔性旋转变形假设的刚度模型为基础,提出了基于关节六维柔性变形假设的机器人刚度模型。以KUKA KR16L机器人为研究对象,搭建柔性旋转关节刚度辨识实验平台。采用蒙特卡罗方法对机器人几何参数误差进行数值仿真,评估其对关节旋转刚度辨识的影响。通过对位置精度进行补偿与测量对关节刚度辨识结果进行校核与评估。同时,以处于维护状态下15kg喷涂机器人为研究对象,搭建六维关节刚度辨识实验平台,采用迭代加权最小二乘优化求解方法对其进行辨识。通过位姿精度补偿和测量与对关节刚度机械补偿前后末端执行器振动特性的评估对六维关节刚度进行校核。针对自主研发15kg喷涂机器人轻质化制造的特点,利用夹具原理对其连杆刚度进行辨识与评估。建立连杆-夹具系统刚度与连杆刚度之间耦合关系的数学模型并通过激光跟踪测量系统和加载系统搭建辨识实验平台。采用非线性最小二乘优化求解方法对15kg喷涂机器人腕部第4,5和6连杆的刚度矩阵进行辨识。同时,根据机器人运动学原理,建立连杆刚度对机器人末端执行器柔顺性能影响的评估方法。采用蒙特卡罗方法和枚举法对连杆刚度影响因子在机器人工作空间内的分布特性进行分析,并针对指定离线编程喷涂轨迹设计的合理性进行了数值仿真与评估。最后,根据企业对工业机器人性能检测和评估的需求,针对国际标准ISO9283中重要检测项目位姿准确度、位姿重复性与速度特性的测量规范,利用激光跟踪仪测量系统搭建相应性能检测实验平台,对柔性生产线中典型六自由度关节型机器人：15kg喷涂机器人、昆山一号和KUKAKR16L进行测试,并对其测试结果进行数值评估和比较。
[Abstract]:With the rapid development of productivity and science and technology, the performance requirements of manufacturing automation with six degrees of freedom industrial robot flexible production is more and more high, R & D and the establishment of industrial robot with independent intellectual property rights of the key parameters calibration and experimental method, has become the basic demand for major domestic industry of manufacturing equipment.
In this paper, six DOF articulated robot for research object, in order to improve the performance of the static pose accuracy as the goal, system of robot calibration principle and experimental method were studied. From the perspective of evaluation and measurement method of robot pose accuracy, according to the analysis of end effector pose error sources on the robot end, respectively. To establish the kinematics error model and stiffness model, modeling and simulation is performed and the effects of geometrical parameters of the robot and non geometric parameters on the pose accuracy. At the same time, the parameter optimization method based on the experimental platform to build robot off key parameter identification error, to compensate the end effector of a robot pose error. The experimental principle in robot calibration according to the needs of enterprises and based on the experimental platform to build the industrial robot performance testing, performance for the self-developed six DOF articulated robot The test provides an effective measure and evaluation method. The main contents are as follows:
First of all, according to the industrial robot calibration method and principle, static pose accuracy evaluation and measurement of the six DOF articulated robot. According to the description and Analysis on the pose accuracy in the detection of ISO9283 international standard specifications and requirements, the laser tracking measurement system built pose accuracy detection experiment platform. At the same time, a for pose accuracy measurement of flexible end effector design, complementary detection means provided in the standard, and through the Monte Carlo method on the measurement accuracy of the numerical analysis and Simulation of error.
For the six DOF articulated robot kinematics, respectively set up robot modified D-H parameters (MD-H) and exponential product (POE) kinematics error model. With the enterprise independent research and development of 15kg spraying robot as the measuring object, the robot geometric parameters calibration experiment platform to build the laser tracking measurement system. The identification and compensation of geometric parameters the error of optimal solution by iterative least square method, and the calibration of robot pose before and after the performance analysis and evaluation.
For the six DOF articulated robot compliant characteristics of robot stiffness model is analyzed, and the rigid body kinematics and stiffness model assumes joint flexible rotation and deformation based on the proposed joint stiffness model of six dimensional flexible deformation assumption. The KUKA based robot KR16L robot as the research object, build flexible rotating joint stiffness the degree of identification experiment platform. By using the Monte Carlo method for numerical simulation of robot geometric parameter error, assess the effect of joint rotation stiffness identification. Based on position precision compensation and measurement verification and assessment of the joint stiffness identification results. At the same time, in the maintenance of state 15kg spraying robot as the research object, build six dimensional joint stiffness identification experiment platform, using the iterative weighted least squares optimization method to identify the pose accuracy. Through measurement and compensation The evaluation of the vibration characteristics of the terminal actuator before and after the mechanical compensation of the joint stiffness was checked for the stiffness of the six dimension joint.
According to the characteristics of light manufacturing robot independent research and development of 15kg coating, using the principle of the connecting rod fixture stiffness identification and evaluation. To establish linkage fixture stiffness mathematical model and the linkage between the stiffness of the coupling between the laser tracking and measuring system and the loading system to build experimental platform for identification. By using nonlinear least squares optimization method of identification the stiffness matrix of 15kg robot wrist 4,5 and 6 bar. At the same time, according to the robot kinematics principle, establish linkage stiffness of compliant robot execution performance evaluation method. By using the Monte Carlo method and enumeration method to analyze the influence of connecting stiffness factor distribution characteristics in the robot in the working space, and for the the specified trajectory design of off-line programming spraying the rationality of the numerical simulation and evaluation.
Finally, according to the business needs of the industrial robot performance testing and evaluation, the important items of international standards ISO9283 pose accuracy measurement standard pose repeatability and speed characteristics, build the experimental platform to detect corresponding performance using laser tracker system, the flexible production line in a typical six DOF articulated robot: 15kg spraying robot, Kunshan 1 and KUKAKR16L were tested, and the test results are evaluated and compared numerically.

【学位授予单位】：华中科技大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TP242

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