| China is a major tobacco producing and consuming country and the rapid development of the tobacco industry has made it an effective way for growers to get out of poverty and become rich.Good quality and abundant yields of tobacco are not only related to the quality of the seeds and the way they are cultivated before transplanting,but are also inextricably linked to post-transplanting operations such as fertilisation,spraying,weeding and topping.As most of China’s tobacco cultivation is concentrated in hilly areas with complex terrain and large undulations,tobacco mulching,transplanting,fertilising,weeding and spraying in hilly areas are currently mainly done manually,which is a traditional operation with low efficiency,high labour costs and easy waste of fertiliser and pesticides.At present,mobile work platforms are mainly used in agricultural production environments with open,flat and other normative factors,and there is less light-weight intelligent agricultural equipment adapted to tobacco field operations in hilly areas.Given that there is a gap in the market for automatic working platform equipment that is suitable for the hilly tobacco field environment,as well as the background of agricultural information technology and intelligence,it is necessary to research a light and simple tobacco field mobile platform that combines intelligence,flexibility and efficiency and is suitable for the hilly tobacco field operating environment.The successful application of an intelligent tobacco working platform will effectively improve operational efficiency and reduce labour costs.The mobile work platform is the basis for automatic operation in tobacco fields and has good expandability,on the basis of which different end-effectors can be added to meet different operational needs and realise different operations.After understanding the production environment and production needs of tobacco fields in hilly mountainous areas of China,referring to different working platforms and their navigation technologies,and analysing the characteristics of machine vision in agriculture,this paper proposes a light and simple working platform with "light and simple" as the main design criterion,and the main research contents are as follows:(1)According to the characteristics of single-row monopoly tobacco fields in hilly areas,the operation flow plan of the working platform is determined,and the structural design of the working platform is completed.The working platform is a three-wheeled structure,with the front wheel as the driving and guiding wheel and the rear two wheels as the driven wheels.The working platform body is 0.46 m long and 0.24 m wide,with an overall mass of 18 kg,and can operate continuously for 8 hours.The working platform is small in size,light in mass and portable,which meets the design requirements of light and simple working platform.(2)The control circuit of the light and simple tobacco field mobile working platform was developed,and the software design of the control system was completed.The upper and lower computers of the operation platform control system were determined to adopt C/S architecture,and the real-time communication between the upper and lower computers was realized by establishing TCP connection through 4G network.The program as a whole is based on multi-process and multi-thread programming,in which the server side of the lower computer includes two parts of Raspberry Pi 4B main controller and STM32 extended controller programming to realize video pushing service,operation platform control and network communication,etc.The upper computer client PC applies C++ programming to realize video pre-processing,target identification,navigation line extraction,control decision,network communication,etc.(3)Proposed a navigation line extraction method based on YOLOv5 for tobacco crop bounding box detection location information,and tested it laterally against the Open CV morphology extraction navigation line method.After testing,the speed of YOLOv5-based method for extracting navigation lines is greatly improved,the system processing time and operation volume are significantly reduced,and the extraction results are not easily affected by light and weeds,which has the advantages of good real-time,strong antiinterference ability and less occupied system resources,and it is more suitable for hilly areas with complex environment of tobacco field planting and operation environment.(4)The test results show that the maximum delay of the operating platform is 251 ms,and the angle error between the fitted navigation line and the actual navigation line is less than 3°;when operating in a simulated operating environment with a monopoly length of10 m and a monopoly spacing of 1.1m,the lateral offset error is less than 0.2m,and the tobacco plants will not be hurt during the travel process,which meets the requirements of the tobacco field mobile operating platform.It meets the requirements of real-time and accuracy of tobacco mobile working platform. |
PDF Full Text Request