Design And Dynamic Characteristics Study On Motion Mechanism Of The Transplanter For Factory Plantation Growing Seedlings

The transplanter for tray seedlings in greenhouse reveals many problems in the experiment,The main rereasons are that the number of end-effectors is small,the gripped seedlings suffer extra movement shock and vibration and the matrix is easy to be damaged、 the bowl seedling may fall off,when the moving part of the tray seedlings. Aiming at the problem,a kind of picking seedings positioning machinery for auto-transplanter was designed,appeasing multiple end-effectors operating together. To improve the stability and rapidity of transplanting,the design of the picking seedings positioning machinery, the transplanting performance and mechanism dynamics analysis were studied. The main research contents are as follows:(1) A kind of picking seedings positioning machinery for auto-transplanter was designed, controling the end-effector to achieve the “rise,translation,descent”three segment line operation and dispersion of multiple end-actuator. The dispersion of end-effectors was achieved by oblique chute of the plate. The end-effector was driven to take the seedling in the horizontal and vertical by the synchronous belt drive mechanism. Meanwhile, the method of adding balance cylinders to assist the movement of synchronous belt driving mechanism was raised. The servo motor system was controlled by PLC, and the hardware of the control system was selected and planned reasonably.(2) The physical prototype was manufactured to examine the actual working performance by some experiments. The position precision was detected by the linear displacement sensor. Testing results showed that in view of the 128-cell tray and 4-cell flower pot, the average step transmissions were 32.2911mm、206.3246 mm.With one-sample t-test, it was found that there was no significant difference(at α=0.05) in the step transmissions between the testing value and the designed value, which demonstrated the reliability of automatic seedlings-picking device. Different work efficiency experiments showed that when the work efficiency was 360 working cycle /h、 720 working cycle /h 、900 working cycle /h,the success rate of taking seedlings is up to 94.2%, 91.0% and 86.7%,Showed that when the take seedlings device at higher speed, had a bad taking seedlings effect.According to the test of dynamics performance,showed that when improving work efficiency,had a low stability.(3) Established mathematical model of kinetics of seedling movement positioning device. The vibration of moving platform was analyzed,and the dynamics characteristics of mechanism was achieved.Through the experiment,the correctness of the dynamic model was verified, established the foundation of dynamics optimization. With the established dynamic model correctly, the change of displacement 、acceleration and velocity under different conditions was analyzed to explore the influence of different load parameters on the dynamic characteristics of transplanting mechanism. Under the high speed operation,light load condition was preferred.(4) The dynamic performance of the mechanism was optimized by improving the outer frame of the moving platform.The simulation results of dynamics performance of the optimized outer frame were compared and analyzed, The optimized quality of outer frame was reduced by 8.83 kg and the vibration displacement was reduced by 20%,The working stability of the mechanism was improved.