Research On Wireless Positioning Technique Of Multi-gripper In Plug Seedlings Transplanting

In recent years,with the development of China's vegetable industry,the traditional manual is difficult to meet the needs of factory nursery.So the plug seedlings transplanting machine has been widely applied in the nursery production.But most of the transplanting equipment have low positioning accuracy,and which associated with it show a mechanical fixed state,it has poor scalability during the transplanting process.In view of above deficiencies,this article design a control system for automatic transplanting.This system mainly include: transplanting part,identification of the plug seedlings and wireless control.(1)The transplanting part mainly composed of mechanical parts,under the "command" of the control system,it can realize the coordinated linkage institutions,it is the premise for the key to transplanting efficient and reliable.(2)The identification of the plug seedlings is a series of pretreatment of the seed images collected by the image acquisition system.The division between seedling and background was realized by gray scale and threshold segmentation;The seedling boundary is smoother by morphological and edge detection,and in line with the appearance of seedlings;The center position of each hole seedling was extracted by centroid method.In the positioning process,by studying the principle of camera calibration,determine the conversion of pixel coordinates and world coordinates,calculate the camera's internal and external parameters.To determine the actual position of the seedlings,and achieve the positioning of seedlings.(3)The wireless transplanting control system mainly includes the PLC control system and the wireless communication part.Through the PLC control system can quickly and easily control the transplanting mechanism of the plug seedlings which were transplanted.In the meanwhile,use the Bluetooth module for wireless transmission.It can enhance the work performance while extended the equipment work space,and avoid the cable winding.In this paper,32 and 96 holes plugs were subjected to repeated the identification experiments.The average recognition rate was about 95%(A group)and 92.71%(B group)verified by trial.Secondly,the positioning accuracy of the transplanting mechanism is measured in the horizontal and vertical direction.The error rate is not more than 1% at the speed of 500mm/s in the horizontal direction,is it not more than 5% at the speed of 400mm/s in the vertical direction;lastly,the transplanting experiments were carried out on the two groups,the average transplanting success rate was about 84.03%(A group)and 81.72%(B group)by the experiments results.