基于改进RRT算法的套管柔性针运动规划

发布时间：2018-08-17 13:53

【摘要】：运动规划是运动控制的基础,然而套管柔性针穿刺软组织的运动规划问题面临着巨大的挑战:一方面由于套管柔性针的运动是个非完整约束运动,另一方面要求套管柔性针绕过人体的某些生理结构障碍和敏感组织准确穿刺靶点。基于分析现有运动规划算法存在的不足,提出基于改进的快速探索随机树(RRT)的套管柔性针运动规划算法。提出贪婪启发策略并结合可达引导策略来改进传统RRT算法;引入直线段路径,采用直线、曲线结合的路径形式;同时考虑入射姿态的规划。基于套管柔性针的运动学模型,分别在二维和三维有障碍环境下进行仿真研究。结果表明,所提出的运动规划算法不论是在运算速度和收敛性上还是在路径形式和搜索的鲁棒性上都优于目前普遍采用的运动规划算法。这些优势为将来的实时运动规划奠定基础。最后对规划的路径进行了穿刺实验,结果证明实验路径与规划路径十分吻合,验证了所提出的路径规划算法的正确性和规划路径的可行性。
[Abstract]:Motion planning is the basis of motion control. However, the motion planning of soft tissue through flexible needle puncture is facing a great challenge: on the one hand, the motion of flexible needle is a non-holonomic constrained motion. On the other hand, the flexible trocar is required to bypass some physiological structural disorders and sensitive tissue puncture targets. Based on the analysis of the shortcomings of the existing motion planning algorithms, an improved flexible needle motion planning algorithm based on a fast exploring random tree (RRT) is proposed. A greedy heuristic strategy combined with reachability guidance strategy is proposed to improve the traditional RRT algorithm; a straight line path is introduced which adopts the combination of straight line and curve; and the planning of incident attitude is considered at the same time. Based on the kinematics model of sleeve flexible needle, the simulation research was carried out in two and three dimensional obstacle environments. The results show that the proposed motion planning algorithm is superior to the commonly used motion planning algorithm in terms of speed and convergence, path form and search robustness. These advantages lay the foundation for future real-time motion planning. Finally, a puncture experiment is carried out on the planned path, and the results show that the experimental path is in good agreement with the planned path, which verifies the correctness of the proposed path planning algorithm and the feasibility of the planning path.
【作者单位】：哈尔滨理工大学智能机械研究所;
【基金】：国家自然科学基金(51305107) 黑龙江省自然科学基金(E2015059,E201448) 黑龙江省教育厅科学技术研究(12531110)项目资助
【分类号】：R61

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