Research On Obstacle Recognition And Avoidance Of Unmanned Tractor

With the in-depth promotion of mechanization and information technology,precision agriculture has become a hot spot in the development of global agriculture.Driverless tractor is an important part of precision agriculture.Obstacle recognition and obstacle avoidance technology,as one of the key technologies of driverless tractor,has become a research hotspot in recent years.Based on ht-1504 d tractor,this paper studies the obstacle recognition and obstacle avoidance methods of unmanned tractor.Firstly,the research status of unmanned tractor and obstacle detection and obstacle avoidance technology at home and abroad is described,the existing problems and shortcomings are analyzed,and the research direction of this paper is clear.Secondly,the test platform of driverless tractor is constructed,and the hardware composition and working principle of the positioning and environment sensing module are analyzed.On the premise of not affecting the original mechanical clutch and full hydraulic steering system of the tractor,a clutch automatic control system is designed by using the scheme that the push rod motor is matched with the fixed pulley block,and the three position four-way proportional directional valve and other electromagnetic devices are used A set of automatic hydraulic steering system is designed.The ht-1504 d tractor is used as the prototype to build the research platform;Thirdly,the obstacle avoidance coordinate model of unmanned tractor is established.After point cloud analysis,de-noising,de-noising,clustering and other processing,the absolute position and motion state of obstacles are obtained by analyzing data correlation evaluation coefficient.An obstacle avoidance strategy of unmanned tractor based on radar monitoring area is designed.From near to far,the radar monitoring area is divided into emergency braking area,obstacle avoidance area and obstacle detection area.The artificial potential field method is improved based on the operation characteristics of unmanned tractor in farmland and the types of obstacles,and the local obstacle avoidance path planning method based on improved artificial potential field is designed.Based on the research of obstacle detection method and obstacle avoidance strategy of unmanned tractor,the control algorithm of upper computer and lower computer is developed,and the control circuit and controller of lower computer are developed based on clutch,solenoid valve and other hardware control requirements.Finally,after the calibration and debugging of each equipment,the static obstacles and dynamic obstacles were simulated according to the field operation conditions for real vehicle test.The experimental results show that the designed obstacle recognition and avoidance method can meet the requirements of obstacle avoidance in the process of tractor operation,verify its functionality and effectiveness,and provide guarantee for the operation safety of unmanned tractor.