Path Planning And Navigation Of Mobile Robot In Dynamic Environment

With the rapid development of science and technology,mobile robots have been widely used in many fields,and have become an indispensable part of social development.The ground wheeled mobile robot is one of the most common robots,and its autonomous navigation ability is a prerequisite for the mobile robot to complete the task.Therefore,path planning is an important problem in the field of mobile robot.It is an important guarantee for the robot to avoid obstacles in the process of moving.Nowadays,mobile robots have gradually become operating in a dynamic environment full of moving obstacles.Therefore,the ability to deal with moving obstacles has become an important and difficult issue in current path planning technology.An important problem in path planning is how to improve the real-time performance of the algorithm and the ability to respond to obstacles,which reflects whether the robot can complete the task timely and accurately.Therefore,this paper takes the two-wheeled differential mobile robot as the research object.The research contents include improving the real-time performance of global path planning algorithm in a known environment and local obstacle avoidance algorithm in a dynamic environment with unknown moving obstacles.The specific content is as follows:In this paper,a kinematics model of the two-wheel differential mobile robot is established,and a raster map is used to model the environment.The characteristics and applicable conditions of the global path planning algorithm and the local path planning algorithm are analyzed.Secondly,this paper introduces the jump search algorithm which is fast in raster map,and analyzes its principle.Aiming at the problem that the search efficiency of hop search algorithm is low in complex environment,an improved method of adding direction discrimination is proposed.This method uses jump search to determine the optimal expansion direction,and iterates to search for jump again when an obstacle is found in the optimal expansion direction.The simulation results show that the improved hop search algorithm can greatly improve the search efficiency in this complex environment.In order to solve the problem of moving obstacles in dynamic environment which cannot be solved by global path planning algorithm,an improved velocity obstacle method combining dynamic window was proposed,and the size of collision cone was dynamically adjusted by using adaptive collision radius.In this paper,the speed obstacle method with fast calculation and high real-time performance is used as the obstacle avoidance algorithm for mobile robot.Speed barrier method assumes that the movement information of obstacles of known and do not change,but in reality because of the sensor noise detection error,such as the actual robot obstacle information can't be the same,so this article is proposed based on adaptive expansion radius adaptive speed barrier method,in order to make sure keep a safe distance between robot and obstacles.The dynamic window method is used to further optimize the feasible velocity space generated by the adaptive velocity obstacle method.Through MATLAB simulation,the results show that the improved speed obstacle method can effectively improve the probability of successful obstacle avoidance,and the speed obstacle method integrating dynamic window can track the global path,and give play to the optimality of the path planned by the global path.