| With the increasing of potato planting area in China,the demand of virus-free potato tissue culture seedlings increased,but the current production of potato tissue culture seedlings mainly used manual operation,production efficiency is low,and the quality of work is not stable.Especially in the inoculation of tissue culture seedlings,due to the huge amount of inoculation,and the technical difficulty is high,the labor efficiency is difficult to meet the large production requirements of tissue culture seedlings,so the demand for automated vaccination equipment is very urgent.In order to improve the efficiency of potato seedling inoculation,reduce the labor intensity of workers,to ensure the quality of inoculation operations,in this study,combined with manual inoculation operation process,generalized the shortcomings of the existing inoculation automation equipment research,a new type of inoculation robot was established which the tissue seedling stem section fixed distance planting,multi-hand parallel inoculation.In this paper,the key research techniques of inoculation robot are studied by means of three-dimensional computer modeling technology,fluid mechanics simulation and calculation,establish mathematical model and experimental verification.The following research results are obtained:1.This research is aimed at the problem of positioning identification difficult and the working space narrowing of the hold hands when tissue culture seedlings palnting in the existing potato culture medium,a operation mode of tissue culture seedling fixed distance planting was proposed;To aim at single-handed serial inoculation time-consuming issues,in order to improve the efficiency of inoculation,the multi-hand parallel inoculationmode was proposed,and whole process of theinoculation robot was designed according to the manual inoculation procedure.The inoculation robot as a whole by a inoculationhold hand for tissue culture seedlings thatready to be vaccinated,three negative pressure inoculation hold hands,a set of stem segmentation mechanism and machine vision and PLC control system.2.The physical characteristics of the potato tissue culture seedlings were measured and analyzed by means of machine vision measurement and mechanical property test platform,which was used to design the target parameters of the key institutions in the inoculation robot.The parameters such as spacing growth point,stem diameter,cotyledon diameter,cotyledon stem length,leaf stem angle,stem section bending deviation,stem mass and other important parameters were obtained,and the length of the stem inoculated was determined to be 10 mm by the distribution of growth points;In addition to that bending stress,plastic deformation radial pressure,flexural capacity and insertion medium resistance of tissue culture seedling were obtained.3.A new type of inoculation hold hand based on the negative pressure airflow mode is proposed and designed.According to the requirement of cutting depth of tissue culture seedlings and the force analysis of tissue culture seedlings in airflow direction,the initial form of suction nozzle of inoculation hold hand was established.The FLUENT software was used to analyze the guide wing angle and the nozzle mouth width,to determine the nozzle mouth of inoculation hold hand for outer diameter of 5mm,inside diameter 4mm round tube,the front of nozzle mouth set guide wings of 90 °,distance of guide wing vertex is 10 mm.4.The experimental study on the guided working method of curved tissue culture seedlings was carried out.1)Through the study on the guiding performance of the negative pressure airflow on the curved tissue culture seedlings,it was determined wheninoculation hold hand negative pressure pipe vacuum reaches 9 × 10-3MPa,it can basically meet the guide operation of tissue culture seedlings of bending deviation in the range of 4mm on the 10 mm length;2)Taking the vacuum degree of the pipeline,the deviation distance and the height of hold as the influencing factors,aiming at the negative pressure adsorption response time,the negative pressure guidance response time regression equation was established by the method of ternary quadratic orthogonal rotation center,andproved its correctness by verification test.3)Guide performance of positive pressure airflow on curved tissue culture seedlings was studied,the results showed that the highest success rate of 93.3% when the diameter of the positive pressure trachea was 4mm,the distance between the nozzle mouth and the positive pressure trachea was 30 mm and the guided air pressure was 0.15 MPa,so using a single tube positive pressure air guide effect is unstable;Using two positive pressure trachea for tissue culture guide,when the nozzle mouth and the positive pressure tracheawas 25 mm,the air pressure can be selected as 0.2MPa,the success rate of guide up to 100%.5.The experiment was carried out to study the hold performance of inoculation hold hand.1)For the segmentation operation of the stem,when the rotate speed of cutting knifereaches 7r / s or more,the straight speed can be 0.03 m / s,holdsuccess rate of inoculation control hand is 100%.2)For theinsertoperation of stem segments,when the insert speed was 0.01 m / s for the whole tissue culture seedlings,holdsuccess rate of inoculation control hand was 100%.3)In order to enhance hold ability of inoculation hold hand,on both sides ofsuction nozzlemouthinstall 0.5mm wide baffle.6.Prototype of inoculation robot for potato tissue culture seedlings was built and operating performance is tested.1)The running speed of inoculation hold hand was measured.The results showed that the horizontal running speed was 0.1 m / s,the maximum running speed was 0.08 m / s in the horizontal vertical direction,and the maximum running speed was 0.12 m / s in the cutting direction,in the above conditions,inoculation control hand can stably handle stem segments.2)Stay time for inoculationwas measured.Results showed that the effect of negative pressure air flow could be completely eliminated after 0.45 s of inoculation,and the withdraw of the hold hand was not affected tissue culture seedling.3)The success rate and operating efficiency of each cycle during the single-cycle inoculation of the inoculated robot were measured.The results are: guide operation success rate is 98%,stem segmentation success rate is 96%,cutting operations success rate is 98%,comprehensive operation success rate is 91%,productivity of one hand serial operating about 550 / h.4)One tissue culture with 3 growth points was inoculated by three inoculation hold hands as an example to calculate the parallel operation mode,productivity of 3 hands in parallel operating about 1270 / h,up to one hand serial operating productivity of more than 2.3 times. |
PDF Full Text Request