颌骨重建手术机器人定位精度分析与误差补偿

Positioning Accuracy Analysis and Error Compensation of Medical Robot Assisted for Mandible Reconstruction Surgery

为提高颌骨重建机器人的精度,借助于—台可以实现绝对坐标测量的高精度光学定位跟踪仪,对机器人系统的定位精度进行了误差分析与补偿研究.针对结构参数和运动变量误差,采用修正的运动学模型,进一步真实地反映了机器人的实际结构参数;对齿轮传动误差和间隙引起的关节回转误差通过实验进行了修正,有效提高了关节传动精度;对零位定位误差,通过机器人逆运动学反解出关节转角,并进行误差补偿,提高了定位基准的精度.实验结果表明上述方法可有效提高颌骨重建机器人的定位精度.

In order to improve the accuracy of the mandible reconstruction robot, the positioning accuracy and error compensation was studied using NDI Polaris based on analysis of surgery procedure. The kinematics parameters were identified based on a revised D-H kinematics model, taking small distortions of the joint axes and link parameter into consideration. Joint transmission error and zero position error were compensated with experiments. Absolute positioning accuracy of the robot was measured using an accurate NDI Polaris measure device according to the model. The experiment results show that the maximum value and the mean value of the absolute positioning accuracy are much better than the previous values after compensating the errors caused by link parameter, transmission and zero position. The method can be widely used in series robot error compensation.