肠道机器人扩张机构设计与优化

发布时间：2018-04-02 08:44

本文选题：肠道机器人　切入点：扩张机构　出处：《光学精密工程》2017年07期

【摘要】：为了满足肠道机器人在肠道中运动和驻留的要求,设计了一种大变径比的新型扩张机构。该机构通过采用双层叠腿式设计,增大了与肠道的接触面积,最大扩张半径达到24.5mm,变径比增加到3.27。为了进一步研究该扩张机构的性能,建立了扩张臂的数学模型,对扩张臂的力学与运动学特性进行了理论分析。然后通过有限元分析,对扩张臂运动过程进行了动力学仿真,研究了不同扩张半径下,扩张臂的应力分布和变化趋势,基于有限元分析结果,对扩张臂进行了优化设计,优化后的等效应力最大值比优化前减小了12.89%。之后通过ADAMS对扩张臂进行运动学仿真,以验证其运动学模型的准确性。最后搭建了力学性能实验台,对其扩张力进行了测试,以验证其力学模型的准确性。实验结果显示:实验值与理论值的变化趋势基本一致,而且实验值小于理论值;机构扩张初始阶段误差较大,扩张半径为7.5 mm时,实验值仅为理论值的14.30%;之后误差急剧减小并趋于稳定,扩张半径为10~23mm时,实验值平均为理论值的73.64%;扩张臂1、2、3的实际扩张半径分别为24.5、24和23mm。结果显示本文设计的肠道扩张机构基本满足肠道安全性和大变径比的设计要求,而且结构优化效果明显。
[Abstract]:In order to meet the requirements of intestinal robot moving and staying in the intestine, a new expansion mechanism with large ratio of variable diameter to diameter is designed.The double leg design is used to increase the contact area with the intestinal tract. The maximum expansion radius is up to 24.5 mm and the ratio of variable diameter to diameter is increased to 3.27 mm.In order to further study the performance of the expansion mechanism, the mathematical model of the expansion arm is established, and the mechanical and kinematic characteristics of the expanding arm are theoretically analyzed.Then through finite element analysis, the dynamic simulation of the expansion arm motion process is carried out, and the stress distribution and variation trend of the expansion arm under different expansion radius are studied. Based on the results of finite element analysis, the expansion arm is optimized.The maximum equivalent stress after optimization is 12.89 less than that before optimization.Then the kinematics simulation of the expanded arm is carried out by ADAMS to verify the accuracy of its kinematics model.Finally, the mechanical properties test bench was built, and the expansion force was tested to verify the accuracy of the mechanical model.The experimental results show that the experimental value is basically consistent with the theoretical value, and the experimental value is smaller than the theoretical value, and the error in the initial expansion stage of the mechanism is large, and the expansion radius is 7.5 mm.The experimental value is only 14.30 of the theoretical value, and then the error decreases sharply and tends to stabilize. When the expansion radius is 10~23mm, the average experimental value is 73.64 of the theoretical value, and the actual expansion radius of the expanded arm is 24.524 and 23mm.The results show that the intestinal expansion mechanism designed in this paper basically meets the design requirements of intestinal safety and large variable diameter ratio, and the effect of structure optimization is obvious.
【作者单位】：上海交通大学电子信息与电气工程学院;
【基金】：国家自然科学基金资助项目(No.61673271,No.81601631) 上海市科学技术委员会科研计划项目(No.14441902800,No.15441903100)
【分类号】：TH776;TP242

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