介入手术机器人滑轮绳索系统传动特性的研究

摘要

Aiming at the problem of nonlinear friction in the movement of the interventional surgical robot,the transmission characteristics of the cable-pulley system were investigated.The classical Capstan equation was used for analysis of the force of the cable in the transmission process.After the analysis of the relationship between friction and wrapping angle,the relationships between friction and material contact characteristics were also established by power law.Then,the input force and output force of the cable in the transmission process were meas-ured by the tension sensor,and the friction of the cable system was tested by changing the wrapping angle.Finally,the accuracy of the trans-mission model was analyzed.The results indicate that the friction of the pulley cable system is related to the contact characteristics of the ma-terial and wrapping angle.When usin g the polymer material as the driving cable and considering viscoelastic deformation,the frictional force of the rope is small and the system transmission efficiency can reach 90％,which ensures the precision of the force control.%针对介入手术导管机器人绳索运动过程中存在非线性摩擦力的问题,对滑轮-绳索系统传动特性进行了研究,利用经典Cap-stan方程对传动过程中绳索受力进行了分析,建立了摩擦力与包角的函数关系,并根据Power法则分析了摩擦力与材料接触特性的关系;利用拉力传感器对传动过程中绳索的输入力和输出力进行了测量,并通过改变包角大小对绳索系统摩擦力进行了实验,分析了传动模型的准确性.研究结果表明:滑轮绳索系统运动过程中摩擦力大小与包角及材料的接触特性有关,当采用高分子材料作为驱动绳索时,考虑到粘弹性变形,绳索受到的摩擦力较小,系统传动效率可到达90％,保证了力控制的精度.