Research On Intelligent Lawn Mower System Based On IMU And DGPS

With the accelerating urbanization,the green area in cities is getting higher and higher,which means that more and more lawns need to be mowed.Traditionally,lawns are mowed manually,which is a boring and heavy project,needing a lot of labor costs.Furthermore,lawn mowing also makes noise and produces air pollution,affecting the health of employees.Therefore,it is necessary to design an intelligent lawn mowing robot to mow lawn automatically.This thesis studies an intelligent lawn mower based on IMU/DGPS,which can mow lawns without human assistance.The main work of this paper is as follows:(1)Firstly,the overall design of the intelligent lawn mower was determined.According to the functional requirements and cost constraints,the design of power module,information sensing module,human-computer interaction module and navigation and positioning control module are determined respectively.Appropriate devices are selected,and circuit is designed to connect the devices.(2)An attitude control method is proposed according to the requirements of intelligent mower,in which accelerometer and gyroscope data are fused by Kalman filter to realize the control of pitch and roll;gyroscope data and hall data are fused by Kalman filter to control heading angle.Furthermore,IMU data is also employed to control straight-line walking using fuzzy PID control.Finally,the performance of attitude control and straight-line walking control are tested respectively.(3)A navigation and positioning system based on IMU/DGPS is proposed according to the navigation and positioning accuracy requirements of intelligent mower.The operating principle of DGPS is introduced,and a low cost DGPS working in embedded systems is realized.The unscented Kalman filter is employed to fuse IMU and DCPS data to realize IMU/DCPS complementary navigation and positioning scheme.Finally,the performance of the proposed navigation and positioning system is verified.(4)The control algorithms and strategies of each function of intelligent mower are proposed based on the navigation positioning method,attitude control method and straight-line walking method.These functions include path-planning function,autonomous charging function,obstacle avoidance function and security function.(5)Finally,the experiment platform of intelligent lawn mower is built,and the software implementation of each functional module based on operating system programming is introduced.The implementation of each function is also tested on the experiment platform of intelligent lawn mower.Experiments show that the intelligent lawn mower studied in this thesis can independently complete mowing the determined mowing area,and can realize self-charging,intelligent obstacle avoidance,and security function,which meets the functional requirements and cost requirements of intelligent mowers.