Research On The Control System Of Precision Automatic Weeder Based On Machine Vision

The modernization of agricultural machinery and equipment is the important material basis of agricultural modernization.In order to promote the process of agricultural modernization,it is necessary to develop intelligent agricultural machinery equipment.In this paper,the current popular machine vision technology,sensor technology and hydraulic control technology combined with the weeding machine,committed to the realization of agricultural weeding equipment automation,intelligent.In order to achieve accurate and effective control of the weeder in the working process,this paper focuses on the following aspects:(1)A weed control scheme was proposed,which could simultaneously remove weeds in and between rows of field crops.The scheme firstly uses machine vision technology to locate the field plants,and then controls the weeding tool to avoid the plants and remove weeds in the moving process of the weeding machine.The purpose of designing the scheme is to realize the full range continuous weeding in and between rows of farmland crops.(2)In-depth analysis of the structure and composition of the control system of this topic.The control system is divided into three parts: input(visual image processing system),controller processing(online real-time control system based on fuzzy PID control algorithm),actuator(hydraulic system and weeding tool),and the realization method of each part is studied.(3)An image processing algorithm program is designed to distinguish the planting situation of farmland plants and determine the position of the root of farmland plants.This program not only enables the weeder to be used in a variety of scenarios,but also has high execution efficiency.After many tests,the average processing time of a 480x640 resolution picture is 0.25 seconds,which can meet the requirements of this project.(4)Based on C/S distributed mode,the network communication module is developed,and the data communication between server(embedded development board)and client(PC host)is realized with the help of database technology.And in order to ensure the stability of the network connection between the server and the client,the heartbeat detection mechanism and the exception handling mechanism are added in the program implementation of the server and the client.In addition,in order to ensure the timeliness of the communication,the asynchronous communication between the server and the client is realized by using the multi-thread programming idea.(5)Sensor technology,data acquisition technology and hydraulic control technology are used to control the actuator of the weeder.The position information of the weeding cutter is fed back by the pull rope displacement sensor,and the rotation speed of the cutter is measured by the encoder.The output channel of the control signal and the input channel of the feedback signal of the control system are provided by the data acquisition card.The closed loop control method based on fuzzy PID algorithm is used to control the position of the cutter,while the speed of the cutter is controlled by open loop control.(6)Based on the laboratory environment,the final results of the subject were verified and analyzed..The experimental results show that the data after image processing can be timely received by the hydraulic control system,and the response speed and precision of the system can meet the requirements of the project.