Design Of Monitoring System For Vegetable Precision Seeding Test Rig

As the second most important agricultural products after grain crops in China,the demand and quality requirements for vegetables are increasing.Precision seeding is not only efficient,but saves a lot of manpower and material resources,and also has good seeding effect.It can improve vegetable yield and quality from seeding link.However,in the precision sowing,the sowing process is usually completed in the seed metering device.When there is emptying or failure in the box,the problems of missing species and damaging the machine will be caused,especially the small grain size and variety of the vegetable seeds,which can cause accident in the sowing easily.Therefore,it is of great significance to design a monitoring system for the precision sowing of vegetables to ensure the high efficiency and high quality of the sowing process.By analyzing the research status,advantages and disadvantages of the precision seeding monitoring system were greatly observed and compared both at home and abroad.hn addition,combining sensor technology,modern control technology with visual software development technology,a set of monitoring and control system suitable for precision seeding of vegetable seeds was designed in this paper.The real-time monitoring of the parameters such as the number of seeds per hole,seeding speed,hole spacing and leakage replanting in the process of seeding with small diameter vegetable seeds was realized,and the evaluation indexes such as the qualified index of seeding machinery,also the index of missing replanting and the standard deviation of qualified hole distanee were analyzed and calculated.The main tasks accomplished are summarized below:(1)The physical parameter information of vegetable seeds was measured and analyzed,the evaluation index of seeding machine and the monitoring system were determined,and the overall scheme design of monitoring system for precision seeding test bed was completed.Some common vegetables,such as Chinese cabbage,non-heading cabbage,turnip,pepper,carrot,celery and so on,were selectedand some physical parameters of them,such as particle size,1000-grain weight,appearance shape and floating characteristics,were measured.Based on the national standard of precision seeding,five monitoring and controlling contents,includingmiss-seeding,reseeding,sowing speed,hole distance and sowing condition,as well as four evaluation indexes,including qualified index,missed seeding index,reseeding index and qualified point distance standard deviation were determined to study mainly in this paper.(2)According to the monitoring requirements of the monitoring system,the hardware system of the monitoring system for the precision seeding test bed was designed.The hardware system was based on the data acquisition card USB-6009,mainly designed the monitoring module,sowing speed monitoring and control module,acousto-optic alarm module,etc.According to the characteristics of small diameter of vegetable seeds,the optical fiber sensor was selected as the monitoring device for seed metering,and the installation structure was designed to solve the problem of small diameter of vegetable seeds and difficult detection.According to the system design,the anti-interference design was carried out.(3)According to the hardware system and monitoring requirement,the software system of vegetable precision seeding test rig was designed.The software system adopted modularization idea,and designed the eollection and proeessing module of seed discharge information,motor drive and control module,man-machine interaction module,seeding performance analysis module and so onbased Lab VIEW platform.The real-time collection of parameters such as leakage replay,seeding speed,hole distance,etc.have realized.By designing PID algorithm,the stable regulation and control of seeding speed have been realized,and the speed matching between them was ensured.The man-machine dialogue was realized through man-machine interface and acousto-optic alarm device,and seeding performance analysis program was designed based on national standard;Based on SQL Server 2008,the system database was designed,and the real-time storage and call of the parameters were realized.(4)According to the actual design of hardware and software and according to the requirements of the national precision seeding test,the monitoring system of the precision seeding test rig for vegetables was studied.According to the design of seeding device,the seed number,particle size,falling time interval and passing speed were monitored and tested.The results showed thatthe design of sowing part was stable and reliable.The monitoring accuracy of single,double and multi-grain seeding was97.08%91.19%and 66.04%respectively;The monitoring accuracy of grain size above 1mm was over 97%,and the accuracy of particle size below lmm was 86.63%;The accuracy of falling time interval above 0.2 seconds was more than 97%;The accuracy of differentspeed monitoring was about 97%.Based on the design of speed detection and controlling,the speed measurement,interference test and speed matching test were carried out.The experimental results showed that the speed detection was stable and reliable,and the error rate of sowing speed monitoring is less than 5%;The system could be adjusted to the nonnal level within 3seconds when the broadcast speed fluctuateed.When the sowing speed was adjusted greatly,metering plate lagged 1.7seconds to adjust within 5 seconds to complete matching.The system integrity test was designed for the whole system.The experimental results showed that the monitoring system was stable and reliable and realized the real-time monitoring of seeding process.