| With the development trend of Industry 4.0,Internet of Things and Intelligent Manufacturing,automation and flexibility of industrial production are two core themes.Logistics between workshop and warehouse is one of the important links in manufacturing process.Because of the complex and diverse production environment,especially for the production and inspection workshops with short production cycle and more manual participation,the effect of traditional logistics transportation is unsatisfactory.Considering the demand of manufacturing enterprises for automatic and flexible logistics transportation,this paper designs and builds an autonomous mobile logistics robot system,which is using SLAM technology and map-matching navigation method based on twodimensional laser radar.Without depending on external auxiliary equipment,this logistics robot system can locate itself in real time,navigate to specific place independently,and thus,realize the flexible and intelligent logistics transportation of mobile robots in industrial environment.The research work in this paper is as follows.Firstly,combining with the actual needs of enterprises and the actual work scen,the system composition is determined step by step from the functional requirements,structural scheme and equipment selection,and finally a set of logistics mobile robot system is built.Then,by analyzing the motion model of the logistics robot platform and the observation model of the environment sensing sensor,using the map building algorithm and Monte Carlo particle location algorithm.In order to improve the efficiency and accuracy of particle filter in the initial positioning process,an improved method using "map gradient expansion matching" is proposed.In the case of obtaining two-dimensional grid map of the environment and the location of logistics robot in the map,this paper analyses several commonly used path planning algorithms for grid map and puts forward some optimization measures to effectively improve the continuity of path planning,such as eight-neighborhood exploration,considering the steering cost.Finally,the strategy of "improved A* global path + improved BFS local path planning + DWA real-time path planning" is adopted to realize the autonomous navigation between workshop and warehouse of logistics robots,so that it has the ability of autonomous obstacle avoidance when encountering obstacles.At the end,a simulation model is established through Gazebo simulation system,which verifies the feasibility of the scheme,and a special call system is designed for workers.After debugging and calibration,the logistics robot can finally navigate between the manufacturing workshop and the warehouse by itself,and the navigation accuracy can be controlled within 20 cm. |
