基于非均匀环境建模与三阶Bezier曲线的平滑路径规划

Smooth Path Planning Based on Non-uniformly Modeling and Cubic Bezier Curves

针对工作于复杂环境下的大型工装,本文提出了一种基于非均匀环境建模与三阶Bezier曲线的平滑路径规划算法,以指导工装的运动.在环境建模方面,利用四叉树建立环境的非均匀模型,能够有效压缩环境信息,提高搜索效率;在路径搜索方面,以非均匀环境模型为基础,提出一种距离启发搜索和信息素混合更新的蚁群算法,能够得到工装的安全可行路径点;在路径平滑方面,基于三阶Bezier曲线,提出能够连接任意位置和任意方向两点的转弯单元的设计方法,利用转弯单元连接路径搜索算法得到的路径点,能够获得满足工装非完整性约束的平滑路径.最后,以大型激光驱动器的靶场环境为对象,对本文算法的有效性和可靠性进行验证,并利用DELMIA平台进一步验证了规划路径的运动平滑性和安全性.

In this paper, a path planning algorithm is proposed to search feasible paths for an auxiliary robot working in complex environment. The movement of the robot could thus be guided by the planned result of the algorithm in assembly practice. In the process of environmental modeling, a quad tree method is employed to construct the non- uniform environmental model, which decreases the amount of environmental information to a minimum as needed. As a result, the searching efficiency is improved. In the process of path searching, on the basis of the predefined non-mfiform environmental model, an improved ant colony algorithm is presented to search the path points for the robot, which adopts distance-based heuristic search method and fusion of two different pheromone updating mechanisms. In the process of path smoothing, Bezier turn is designed based on cubic Bezier curves to connect two arbitrary configurations. Bezier turns are used to fit a sequence of objective points offered by the improved ant colony algorithm, so that a smooth path satisfying the robot＇s nonholonomic constraints can be obtained. Finally, the method is experimentally demonstrated in target area with large laser facility. Furthermore, the feasibility and security of the planned path is verified based on the platform of DELMIA.