基于关节自由度约束的上臂轴旋转跟踪误差补偿  

Tracking Error Compensation of Upper Arm Axial Rotation with Joint DOF Constraint

作　　者：荆旭[1] 邱世广[1] 范秀敏[1,2] 何其昌[1,2] 

机构地区：[1]上海交通大学机械与动力工程学院,计算机集成制造研究所,上海200240 [2]上海网络化制造与信息化重点实验室,上海200030

出　　处：《上海交通大学学报》2014年第12期1667-1674,共8页Journal of Shanghai Jiaotong University

基　　金：国家自然科学基金资助项目(51475291)

摘　　要：针对外敷跟踪器下皮肤组织滑移(Soft Tissue Artifact,STA)引起的人体运动跟踪中上臂轴旋转角位移跟踪误差问题,基于关节自由度约束,提出一种利用相连肢体相对位姿矩阵分解的在线STA误差补偿角度计算方法.首先,利用一组不包含上臂轴旋转的上肢运动轨迹跟踪信息,基于关节点位置连续和旋转自由度约束,通过优化方法计算各肢体分段坐标系到相应跟踪器坐标系的位姿变换矩阵;然后,上肢实时运动跟踪时,对上臂和小臂相对姿态矩阵引入上臂轴旋转STA误差补偿运动,在肘关节两旋转自由度的基础上进行3自由度的旋转矩阵分解,得到STA误差补偿角度.4人上肢运动跟踪实验表明:在不同肘关节内曲角度条件下,均能有效在线修正上臂轴旋转STA跟踪误差,且在旋转角度较大时,补偿精度优于线性STA误差补偿方法.Soft tissue artifact（STA）is the main error source in upper extremity motion tracking using skinmounted marker sets,especially in upper arm axial rotation.To address this problem,an online upper arm axial rotation angular tracking error compensation method was proposed using matrix decomposition of the relative pose data between the connected bodies based on the joint DOFs constraint.Frist,the transformation matrix between the coordinate of each limb segment to the responding tracking sensor was calculated by optimization method using agroup of upper extremity motion information with no upper arm axial rotation.In this situation,the relative attitude from the forearm to the upper arm would comply with the two DOFs constraint of elbow.Then,an error compensation motion for the tracking deviation caused by the STA of upper arm axial rotation was introduced into the relative attitude.The compensation angle was calculated online by the decomposition of this relative attitude matrix using three DOFs rotational motions when the motion tracking of the movement of upper extremity with upper arm axial rotation.Vivo upperextremity motion tracking experiments of four subjects show that this method can effectively online fix the upper arm axial rotation tracking error caused by the STA.The compensation accuracy is better than that of the linear error compensation method,especially when the rotation angle range is large.

关 键 词：皮肤组织滑移 关节自由度约束 人体运动跟踪 上臂轴旋转 误差补偿 矩阵分解 

分 类 号：TP73[自动化与计算机技术—检测技术与自动化装置] TP391[自动化与计算机技术—控制科学与工程]