Development Of Autonomous Navigation System For Crawler Combine

China is a large agricultural country,the use of agricultural machinery is more and more widely,especially since entering the era of automation,all fields are beginning to seek automated operation,in order to better to liberate human hands,and improve the efficiency of production.Agriculture is no exception,in the past in agricultural production,few automated machinery is used,it will.lead to low efficiency,in order to change this situation,imminent application of automation technology,agricultural automatic navigation technology is undoubtedly one of the most important parts.However the navigation technology used in wheeled vehicles,for the research of tracked vehicles on the less.this paper makes the research from the harvester autonomous navigation on the one hand,through the installation of the GPS sensor on the small crawler combine harvester,complete autonomous positioning of harvester,complete PC programming using VC programming software,to achieve autonomous navigation in the field of harvester.We do the following summary:(1)Based on a complete crawler combine harvester platform,installing differential GPS on it,used to determine the pose information of harvester at different points of time,the installation of IPC control terminal equipment,and the display device used by driver,according to the method of data acquisition and installation selection,complete data acquisition equipment,and the original hydraulic the steering mechanism is analyzed,combined with the need to realize the function,design a set of reasonable steering mechanism,then determined by calculating the parameters of the hydraulic valve equipment selection,purchase,installation,complete the transformation of the hydraulic system.Using VC++ to complete PC programming,including data acquisition,interface programming.The control interface includes the differential GPS control area and the state information display area.(2)Determine the navigation line.A field experiment was carried out by differential GPS coordinate data acquisition,a method is proposed to determine the navigation line.Based on the AB coordinates of the two points to determine the initial navigation line,combined with the characteristics of least squares fitting of the navigation line,the purpose is to reduce access to the abnormal value of impact.Determine the other navigation the line is based on the slope into the harvester homework of initial coordinates and initial navigation line calculation can get specific equations.(3)In the navigation test.According to the existing navigation line,get the coordinates and the direction of the crawler harvester through the angle sensor,lateral calculation error and the heading error,based on linear prediction deviation tracking model and crawler steering control method,were carried out in predicting the time 3s and 5s conditions,navigation test,tracked harvesters in the field results show that compared with the two test,3s prediction time the maximum error is about 0.35m,the maximum error of 5s prediction time is about 0.25m.