Obstacle Avoidance System Of Orchard Management Robot Based On Laser Navigation

To increases automation level of orchard management, reduce labor consumption, and further promote the application of robots, an orchard tracked mobile robot is designed in this research,which can be used as orchard pruning, spraying, harvesting operations platform. This paper relies on LMS291 laser rangefinder made by SICK Corporation of German and OrBot-1 mobile robot to explore the environment perception and autonomous obstacle-avoiding. By using the laser scanner for sensing the surrounding environment, an obstacle avoidance strategy of mobile robots was designed,which realized autonomous navigation in simulation of orchard environments,the main conclusion is as follows:(1)In order to decrease data storage and increase the system’s dynamic performance, By using the laser scanner as the tool for sensing the surrounding environment, providing a positioning method for fruit and obstacle.(2) A dynamic rolling window within the scope of the scanning laser sensor was established according to current location,this window updates its entries each time with the advance of the robot. And the paper achieved conversion from the completed polar coordinates to rectangular coordinate,eliminating the disturbing of the surrounding environment, accomplish coordinates positioning of the obstacle.So these provide a good data support for the robot’s automatic obstacle avoidance.(3) A proportional controller based on PID theory was designed to navigate the robot move automatically in straight line, A Hough transform was used as the algorithm to recognise the tree row,and finding the center line of the tree roots as a navigation path. The results showed that when the robot in a simulated environment with 0.14m/s when traveling for maximum lateral deviation of 0.26m.(3) The robot has used the fuzzy logic control algorithm to design a fuzzy controller, and the fuzzy controller takes lateral deviation and course angleas its input parameters, the change of Au tracked as output controller. When obstacles in both side in fruit row, designed the corresponding avoidance strategies.(4) The whole controlling program of the system is designed base on VC ++ as a development platform, completed from the navigation data acquisition, designed path planning algorithm,to send control instructions to perform.Experiment shows that the system can be successful in walking for obstacle avoidance of fruit trees.