Mobile Robot Autonomous Navigation In Large-scale Outdoor Environments

Robot is a comprehensive embodiment of artificial intelligence technology for practical application,with the rapid development of artificial intelligence in recent years,the research on robots has made great progress,however,how to ensure that mobile robots working in large-scale outdoor and complex wide range environments with stable autonomous navigation ability is still a challenge.In this paper,the mobile robot wheel odometer or inertial is used to provide the robot with a rough pose,then the laser is used to correct the robot's rough pose to get robot's accurate positioning,which forms the robot's localization system.This paper proposes a global path planning based on the multi-navigation mode by using the global geometric topology map constructed in manual or automatic mode,according to different navigation requirements of navigation users,different graph search algorithms are used to plan a global path for the robot,the smoothing optimization of the global path is performed through cubic B-spline interpolation to ensure that the robot will not cause navigation failures due to sudden changes in the path curvature.According to the global path and a real-time local grid map,the paper generates a set of robot's trajectories with the robot position as the origin,obstacle detection is performed on the set of robot's trajectories,and then the trajectories' set is optimally selected according to the constraints set by users,when the optimal trajectory is already selected,robots are controlled to travel along the optimal trajectory.In the actual experiment,mobile robot autonomous navigation caused navigation failures when using multi-trajectories local path planning based on constraints selection in some extreme environments where there are narrow or few passable regions.In order to solve the problem,this paper proposes a local path planning algorithm based on the robots' motion states' clothoid curve trajectory generation,and realizes the robot's navigation in extreme environments.In addition,the paper points out the shortcomings of the local grid map,proposes a method for constructing a multi-level hexagonal grid map,and experimentally proves the practicability of the method.This paper constructs an autonomous navigation system for mobile robots suitable for outdoor large-scale environment,and uses the actual experimental platform to complete long-term autonomous navigation test with a distance of 2.4km and a duration of 1h30 min in the factory area,it also uses the platform to achieve autonomous navigation in a campus environment.These navigation tests proved the stability and reliability of the autonomous navigation system.This paper also uses another experimental platform to transplant the navigation system,and carries on tests in the school environment.It proved the portability of the system.