Path planning method with obstacle avoidance for manipulators in dynamic environment

Gang Chen,Dan Liu,Xiaodong Zhang,Yifan Wang,Qingxuan Jia

doi:10.1177/1729881418820223

Abstract

Obstacle avoidance is of great importance for path planning of manipulators in dynamic environment. To help manipulators successfully perform tasks, a method of path planning with obstacle avoidance is proposed in this article. It consists of two consecutive phases, namely, collision detection and obstacle-avoidance path planning. The collision detection is realized by establishing point-cloud model and testing intersection of axis-aligned bounding boxes trees, while obstacle-avoidance path planning is achieved through preplanning a global path and adjusting it in real time. This article has the following contributions. The point-cloud model is of high resolution while the speed of collision detection is improved, and collision points can be found exactly. The preplanned global path is optimized based on the improved D-star algorithm, which reduces inflection points and decreases collision probability. The real-time path adjusting strategy satisfies the requirement of reachability and obstacle avoidance for manipulators in dynamic environment. Simulations and experiments are carried out to evaluate the validity of the proposed method, and the method is available to manipulators of any degree of freedom in dynamic environment.

Highlights

Manipulators have raised their intelligence level in recent years, and they are no longer confined to help or replace human beings to complete the onerous and complex tasks only in static environment
A path planning method with obstacle avoidance based on the improved D* algorithm is proposed in this article
A path planning method with obstacle avoidance based on the improved D* algorithm is designed to help manipulators to avoid obstacles once the collision detection results are obtained

Summary

Introduction

Manipulators have raised their intelligence level in recent years, and they are no longer confined to help or replace human beings to complete the onerous and complex tasks only in static environment. When we preplan the global path, we would obtain the point-cloud model of the manipulator and the environmental information of the preexisting obstacles In this way, we can detect the collision to choose feasible nodes. Step 1: Based on the results of collision detection, judge whether the sub-path between the current node and its nominal parent node passes the collision danger zone when manipulator running along the global path in real time, if so, go to step 2. The information of the optimized global path is used, and D* algorithm is improved through introducing the collision danger zone, obstacle-avoidance path planning with good real-time property in dynamic environment could be reached. The real-time property and obstacle-avoidance effectiveness of the proposed path planning method are verified

Conclusion

Declaration of conflicting interests