摘要
对一种可重构模块化机器人系统进行定位精度标定方法研究。采用装配映射矩阵描述任意给定的模块化机械臂组成模块间的装配关系,并根据装配信息自动生成指数积形式的运动学模型。根据指数积公式中关节旋量坐标的理论值和实际值之间的伴随变换关系将运动学模型改写成包含关节约束条件的等价形式。对运动学方程取微分得到机械臂末端定位误差与关节旋量误差及零位位置误差间的线性化模型。给出了一种基于最小二乘法的运动学参数标定模型及其生成方法。通过程序生成一种5自由度模块化机械臂的标定模型并采用激光跟踪仪作为测量设备进行运动学参数标定试验。试验结果表明标定过程能够快速收敛到稳定值。测试结果表明经参数标定机器人的平均定位精度提高了近4倍。
The positioning accuracy calibration method for a reconfigurable modular robot system is studied. The assembly incidence matrix is defined to describe the assembly relationships of adjacent models for any given configuration of the modular robot. According to the assembly information the kinematics is built in product of exponentials （POE） form automatically. According to the adjoint transformation relationship between the theoretical value and the actual value of joint twists in the POE formula, the kinematics is transformed to an equivalent form including the joint constrains. The linearized equation is got by differentiating the kinematics equation so as to describe the relationship between the positioning errors in the end of the manipulator and the errors in the joint twists and in the zero position. A kinematic parameters calibration model is presented based on the least-squares method and its generating method. The calibration model of a 5-DOF modular manipulator is given by program. Taking a laser tracker as the measuring equipment, the kinematic calibration experiment is taken out. The experimental results show that the calibration process can converge to stable value rapidly. The testing results show that the average positioning precision is increased about 4 times.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2014年第3期33-40,共8页
Journal of Mechanical Engineering
基金
国家自然科学基金(60905048)
机器人学国家重点实验室自主课题(RLZ200802)资助项目
关键词
可重构模块化机器人
指数积法
参数标定
reconfigurable modular robot
product of exponential
parameter calibration
