一种多关节机器人几何标定方法研究

Research on Geometric Calibration Method of Multi-joint Robot

多关节工业机器人机械臂的实际几何参数与理论几何参数之间由于加工误差和金属热胀冷缩等原因产生的误差,会影响其末端重复定位精度。为提高其末端重复定位精度,提出一种基于标准量具和遗传算法相结合的多关节工业机器人几何参数校准方法。该方法首先在机器人末端固连千分表,其次控制机器人带动千分表对固定在工作空间内的量块从多个方向取多点进行进给检测,最后由千分表数据和标准量块共同确定检测误差,并采用遗传算法优化几何参数,寻找一组最优的参数使检测误差最小。校准后的机器人运行结果表明,经过几何尺寸校准的机器人,其末端重复定位精度由0.300 mm提高至0.100 mm,证明了该方法的有效性。该方法可以实现机械臂几何参数的实时校准和补偿,方法简便,容易实施,无需专业的实验室和测试人员,可以广泛应用于各种工厂环境。

The error of industrial robot arm between actual geometrical parameters and theoretical geometrical parameters which caused by processing errors and expanding of Substance with Heat and Contracting with cold and other reasons,which will affects the repeat positioning accuracy of the robot arm.A calibration method based on standard gauges and genetic algorithm for multi-joint industrial robots was proposed to improve the repeatability of the extremity of the robot.The method is to attach a micrometer at the end of the robot and running the robot to drive the micrometer to feed detection at the measuring block fixed in the working space from multiple directions and take multiple points.The detection error is jointly determined by the dial gauge data and standard gauge blocks,and optimize the geometric parameters using genetic algorithm to finding a set of optimal parameters to minimize the detection errors.Running the robot after calibration,the result indicate that the extremity repeat positioning accuracy of robot was improved from about 0.300mm to 0.100mm,which proved the effectiveness of the method.This method can realize the real-time calibration of the geometric parameters of the robot arm,and is simple and easy to implement,the method need neither professional laboratories nor testers,and low cost,and suitable for use in normal factory environments.