具有确保安全距离的A^*路径优化方法  

Improved A-star Algorithm for Safety Insured Optimal Path with Smoothed Corner Turns

作　　者：段书用 王启帆 韩旭[1,2] 刘桂荣[3] DUAN Shuyong;WANG Qifan;HAN Xu;LIU Guirong(State Key Laboratory of Reliability and Intelligence of Electrical Equipment,Hebei University of Technology,Tianjin 300131;Tianjin Key Laboratory of Power Transmission and Safety Technology for New Energy Vehicles,Hebei University of Technology,Tianjin 300131;Aeronautical Engineering and Mechanical Engineering,University of Cincinnati,Cincinnati 45221,USA)

机构地区：[1]省部共建电工装备可靠性与智能化国家重点实验室(河北工业大学),天津300131 [2]天津市新能源汽车动力传动与安全技术重点实验室(河北工业大学),天津300131 [3]辛辛那提大学航空工程和机械工程系,美国辛辛那提45221

出　　处：《机械工程学报》2020年第18期205-215,共11页Journal of Mechanical Engineering

基　　金：河北省重点研发计划资助项目(19227208D)。

摘　　要：机器人或机械臂在工作空间中,路径的合理规划是提高搜索效率、减小搜索距离、确保作业安全的关键。现有的路径规划算法搜索过程复杂,在减小搜索距离的同时牺牲了对安全性的高可靠度考量。因此,本文提出一种改进的A^*路径规划算法,在保证搜索效率的同时,确保沿着路径执行任务时的安全性。通过4邻域搜索A^*算法与多邻域搜索A^*算法的搜索时间、搜索距离、转折点个数对比,选择搜索时间较短,转折点个数较少的4邻域搜索作为搜索方式;在标准A^*算法中加入安全距离矩阵,并改进其启发函数。提出针对不同环境条件下保证路径安全性要求的具体方法;提出基于不同环境工况条件下可确保安全距离的轨迹优化方法。研究结果表明本研究提出的改进A^*算法的路径转折点少,搜索时间短,后处理简便,且能确保沿着路径执行任务时的安全性。Optimal path planning for automated operators,such as robots or mechanical arms,in the workspace is of importance to improve the efficiency in terms of minimized operation distance and ensure the operation safety along the optimized working path.The existing path planning algorithms,however,still have some limitations,such as complicated searching process,and most importantly omissions of safety considerations while the searching distance was reduced.An improved A-star optimal path planning algorithm is proposed,which produces safety-insured optimal path that are further fine-tuned with smoothing turning corners.First,a comparison study is carried out for a number of neighborhoods searching algorithms in the family of the A-star approach.It is found that the simplest four neighborhood A-star searching algorithm is often most practical in the searching time,searching distances and the number of turning points.Next,we introduce a matrix in the A-star algorithm,that ensures safety distances for operations along the optimal path.In addition,the heuristic functions used in A-star algorithms are modified to ensure the optimal safety path under different environments.Finally,the optimized path trajectory is further fine-tuned for smoothing corner turnings.The proposed algorithms are tested using a number of examples with complicated obstacles.The results show that our improved A-star algorithm has fewer and smoother turning corners,shorter searching time,and simpler post-processing.Most importantly,it ensures the safety for operations along the optimized path.

关 键 词：机器人 路径规划 A^*算法 安全距离矩阵 启发函数 路径轨迹优化 

分 类 号：TP242.6[自动化与计算机技术—检测技术与自动化装置]