Research On Path Planning And Motion Coordination Algorithms For Mobile Robot

With the advancement of science and technology,robots have an increasingly important position and have begun to be widely used in logistics,medical,military and other industries.With the deepening of robotics research,multi-robot systems have become a research hotspot for scholars in recent years,among which path planning and motion coordination are common and important problems in multi-robot systems.The current method for solving the path planning problem is still difficult to meet various environment models,and the motion coordination problem is affected by the path planning problem.Therefore,researches on the path planning algorithm that can be more adaptable and the motion coordination algorithm that can solve the problem better have always been the hot issues for researchers.This paper takes the mobile robot in a two-dimensional static environment as the research object,and decomposes the motion coordination problem of the multi-robot system into the path planning problem of a single robot and the coordination problem between multiple robots.The main work and results are as follows:(1)For the path planning problem of the mobile robot,an algorithm called Iterative Obstacle Avoidance Search(IOAS)is proposed to quickly plan the optimal path and be applicable to various environment models.In the IOAS algorithm,according to the start point and target point of the robot and obstacle information,a method is designed to build a path network by gradually expanding the effective edges,and it is proved that the path network must contain the shortest path.For speeding up the network construction,the collision detection algorithm is improved,and a method for bypassing the obstacle when the path collides with the obstacle is proposed.(2)For the coordination problem,each path is divided into multiple path segments according to the conflicting area,and then combining with the constraint of robot kinematics,the constraint of the order of conflicting areas and the constraint of the rationality of time and speed,a model of motion coordination problem with the optimization objective of minimizing time is constructed.For solving the problem model,an optimization algorithm combining the Zoutendijk feasible direction method and the Branch and Bound algorithm is proposed,and a heuristic generation strategy is designed to obtain the initial solution of the model.Experiments show that the path network constructed by the IOAS algorithm can solve the shortest path,and it takes less time to solve the shortest path than using the full path network for large-scale problems.At the same time,the IOAS algorithm is better than two state-of-the-art algorithms in the literature on the solving quality.For the coordination problem,the experimental results show the feasibility of the problem constraint model,and the hybrid optimization algorithm can solve the approximate optimal solution of the model in a short time.