Simulation And Application Research On Turnover Motion Of The Automatic Orientation Of Ovoid Agricultural Products

The mechanical automatic orientation technology according to the pointed and blunt ends of the ovoid agricultural products is composed of axial motion and turnover motion.Turnover motion is the key motion of orientation after the axial motion.After the directional processing of ovoid agricultural products,it can effectively increase the aesthetics of product packaging and enhance the additional value of commodities.It can also reduce transportation and handling machinery damage and extend the shelf life of the eggs.However,due to the diversity and the randomness of basic characteristic parameters of ovoid agricultural products,as well as the complexity of the influencing factors of the turnover motion,it is impossible to understand the relationship between the motion laws and influencing factors under the real test conditions.Especially in the dynamic analysis,the real tests have great limitations,and it also increases the research workload and work cycle greatly.Therefore,the simulation models of turnover motion of the oval body agricultural product and the egg were established and verified by ADAMS.The theoretical calculation method of the side slip angle was established and verified.Based on the simulation model,the influencing factors and the dynamic parameters of the turnover motion were analyzed,and the working parameters of the turnover motion were optimized.The simulation model of the automatic orientation device for the pointed and blunt ends of ovoid agricultural products was constructed,and the adaptability of the simulation model to different types of agricultural products was analyzed.The results of the study laid the foundation for the establishment of the mechanical automatic orientation technology of oval agricultural products and the optimal design of the device.The main conclusions were as follows.Design a generic model for the simulation of the turnover motion of agricultural products in ovoid.The general simulation model of the ovoid agricultural products on turnover motion was established by ADAMS and MATLAB software.The measurement methods for rolling distance,effect distance of the guide rod in the simulation experiments were created.According to the verification experiments under different egg-shaped angle(3°、5°、7°),long axis(53.2mm、57.2mm、61.2mm),short axis(40.6 mm、43.6 mm、46.6 mm),center distance of the conveying roller(50 mm、55 mm、60 mm),bending angle of the guide rod(15°、30°、45°),and conveying speed(30 mm/s、50 mm/s、70 mm/s).The research showed that the actual test results and the simulative results had consistent variation discipline,and the relative error is within 10%.The simulative model was credible and effective,using this model to study the discipline of turnover motion was feasible.Design the simulation model of egg turnover.Based on the general simulation model,the simulation model of the poultry egg was established.The measurement function for the simulation value of the side slip angle of the poultry egg was created.The theoretical calculation method of the slip angle was constructed.It has been verified by experiments of 10 eggs and 10 duck eggs.The research showed that the relative errors between the simulative values and the actual values of the rolling distance and effect distance of guide rod were within 10%,and the relative errors of the side slip angle on turnover motion was within 15%.The simulation model of eggs’ turnover motion is effective and credible.It was feasible to use simulation experiments to replace physical prototype tests.The theoretical calculation method of the side slip angle established by geometric relationship was reasonable.The value of the side slip angle calculated according to the theoretical formula was credible.Study the dynamic characteristics of the egg turnover process.Based on the simulation model on turnover motion,the dynamic parameters such as centroid velocity,centroid acceleration,angular velocity,angular acceleration and force of the eggs were simulated and analyzed.The research showed that the centroid acceleration and angular acceleration of the eggs fluctuated steadily around the value of 0 for a period of time after contacting the guide rod,the eggs moved and rotated at a constant speed,and the force parameters including the support force,friction force and gravity force were 0 during the stable fluctuation phase.The force situation of the eggs maintained a dynamic equilibrium relationship until it reached a critical state.Under the critical state,there was a certain side slip angle between the egg and the conveying rollers.Study the influence of different working parameters on the turnover motion of eggs.Based on the simulation model on turnover motion,the influence of all factors including different basic parameters of eggs(mass,long axis,short axis,egg-shaped angle),device structure parameters(conveying roller diameter,center distance,guide rod diameter,bending angle of guide rod,friction coefficient between eggs and conveying roller and guide rod,guide rod height from conveying roller)and conveying parameters(speed)on the turnover motion(rolling distance,effect distance of guide rod,side slip angle)were discussed.Among influence factors,the research showed that the long axis and short axis of the eggs,the diameter of the conveying rollers,the center distance,and the friction coefficients between the egg and the conveying roller and the guide rod respectively had the most obvious influence on the rolling distance,effect distance of guide rod and the side slip angle.Egg quality,egg shape angle and conveying speed just had little effect on the turnover motion,and the diameter of the guide rod,the bending angle of the guide rod and the height of the guide rod from the conveying roller had no obvious influence.The orthogonal test method was used to optimize the working condition parameters of the turnover motion simulation model,and the best working parameter combination was determined as the conveying roller diameter was 40 mm,the center distance was 45 mm,and the friction coefficients between the eggs and the conveying roller and the guide rod were 0.6.Design the simulation model of the mechanical automatic orientation device for the pointed end and blunt end of the ovoid agricultural products.A general simulation model of the automatic orientation device for ovoid agricultural products with a continuous simulation of axial motion and turnover motion was constructed,and the simulation model for the automatic orientation device for ten different types of ovoid agricultural products were established.The axial motion parameters(axial distance,horizontal deflection angle)and turnover motion parameters(rolling distance,effect distance of the guide rod)were measured.The research showed that the relative error between the simulated value and the test value of the axial motion parameters were within 10%,and the relative error between the simulated value and the test value of the turnover motion parameters were within 5%.The general simulation model of the automatic orientation device for ovoid agricultural products was correct,and the general simulation model had the same adaptability to different oval agricultural products.The simulation values of the orientation parameters obtained by the simulation model were credible.