| With the development of science and technology and the maturity of wireless sensor technology,agricultural production is moving towards unmanned.As an important part of unmanned construction,agricultural machinery is transforming from traditional to intelligent.The use of targeted spraying robots to precisely apply pesticides to diseased crops can greatly reduce the pollution of pesticides to the environment.The targeted spraying robot with positioning and navigation function can reduce the production burden of farmers,effectively reduce the harm of pesticides to the human body,increase production,reduce production costs,and expand farmers’ production scale.In this paper,aiming at the agricultural field environment and greenhouse,the positioning and navigation technology of the targeted spraying robot is studied,and the practical application is carried out.The main tasks are as follows:(1)The positioning and navigation system scheme of the targeted spraying robot is designed.Based on the demand analysis of the actual application scenarios of the positioning and navigation system functions of the targeted spraying robot,researches were carried out on the hardware structure,the selection of key components,and the software links of information exchange,etc.,and the targeted Design principles and overall framework of the positioning and navigation system of the spraying robot.(2)A compact combination localization algorithm based on extended Kalman filter is designed.According to the actual application scenario of targeted spraying of vegetables in greenhouses,the positioning principles of indoor and outdoor mainstream positioning systems are analyzed and compared,and according to the characteristics of each positioning,a fusion positioning method based on UWB positioning system and IMU positioning system is selected,and a design based on Extending the compact combination algorithm of Kalman filter,this method can effectively utilize the advantages of the sensor and the positioning system to achieve complementary advantages and effectively improve the positioning accuracy.(3)The path planning and obstacle avoidance methods are designed.Through the analysis of the actual application scenarios,the network grid method is used to model the working environment.Correspondingly,the algorithm improvement of the ant colony algorithm’s path selection probability and pheromone update greatly improves the efficiency of path planning.At the same time,the rolling window algorithm is used for local path planning to solve the obstacle avoidance problem.(4)Experiment and prototype development.On the Robot Operating System(ROS)platform,a software program combining positioning module,path planning module and motion control module was developed,a greenhouse cucumber disease and insect pest identification and spray execution system was built,and a targeted spraying robot was developed.Practical tests and applications are carried out.The experimental results show that the positioning and navigation system of the targeted spraying robot designed in this paper can achieve the expected goals of the project and meet the research requirements of the project. |
