Research On Key Technologies Of Automatic Navigation For Vineyard Wheeled Tractor

Based on the grape growing characteristics in Ningxia,this paper designed a set of navigation control system suitable for the vineyard with wheeled tractor as the platform,which can realize the independent navigation of the tractor between the grape rows.This article first analyzes the design requirements of the vineyard navigation system and uses this to design the overall plan.Then analyze the key technologies involved in the navigation system,divide the hierarchy of the navigation system,and conduct corresponding research and design.Finally,the designed navigation system was tested to verify the navigation control effect.The main research contents are as follows:(1)Design the overall scheme of the navigation system.According to the working principle of the vineyard navigation system,the vineyard navigation control system is divided into three levels:environmental information perception layer,navigation control decision layer,and motion execution layer.(2)Design the environment awareness layer of the navigation system according to the characteristics of different work scenarios.Combining with the grape growing mode in Ningxia region,in view of the influence of environmental factors on GPS positioning accuracy,this paper designs three environmental information perception schemes of GPS,lidar and a combination of the two to improve the adaptability of the navigation system to the working environment.(3)Establish the kinematics model of the tractor,and design the navigation decision algorithm of variable universe fuzzy control.(4)Based on the Qt-creator environment,the upper computer of the navigation control system was developed,and the reliability and stability of the upper computer software were verified through relevant experiments.(5)Conduct field tests on the navigation system.The navigation system uses GPS,lidar,and a combination of GPS and lidar environment perception schemes to conduct navigation experiments.When the tractor is traveling at an operating speed of 0.25m/s,the average position deviations of the three schemes are 2.46,2.74,2.96cm,the maximum values are 8.43,9.25,and 10.03cm,and the mean square error values are 2.92,3.64,and 3.3cm,respectively.When the tractor is traveling at an operating speed of 0.35m/s,the average value of the corresponding position deviations of the three schemes is 2.77,2.79,2.79cm,the maximum value is 8.61,9.878,10.88cm,and the mean square deviation is 4.79,4.93,3.64cm.Experimental data shows that the navigation system can control the tractor to travel along the desired path more smoothly,and the control accuracy can reach the centimeter level,which basically meets the needs of navigation control.