Mechanism and experimental study on the fruit detachment of Chinese wolfberry through reciprocating vibration

In order to realize the efficient and high-quality mechanical picking for Chinese wolfberry,firstly,the forced reciprocating vibration picking principle of the Chinese wolfberry branch was studied,and the mechanical model of vibration picking was established based on the simplified cantilever model,and the response analysis and solution of all positions for the branch were carried out.At the same time,the critical mechanical model of fruit detachment under the condition of fruit hanging on branches was established,and the theoretical values of inertia force for each component of the branch were obtained.Secondly,through actual measurement and finite element modeling,the natural frequency and forced vibration response simulation for each component of the branch of Chinese wolfberry terminal branch model were both studied,and the relationship between single-point periodic excitation force and high-quality fruit shedding parameters was obtained.Thirdly,according to the conclusion of the picking model,a test bench with many groups of adjustable parameters was built.Finally,the last branch of fruit-hanging Chinese wolf berry for Ningqi No.1 was taken as the experimental object,a four-level orthogonal experiment was designed with three factors:frequency,amplitude and entrance angle.Meanwhile,the net picking rate,damage rate and false picking rate were taken as the evaluating indicators,referring to the comprehensive scores of the three factors.It was concluded that the primary and secondary relations of factors affecting the picking effect are frequency,amplitude and entrance angle,and the best operation parameters are frequency of 20 Hz,amplitude of 15 mm,and entrance angle of 45°,then,a hand-held vibration picker with setting parameters was trial-produced,and the optimal parameter combination was verified in the Chinese wolfberry planting base of the National Chinese wolfberry Engineering and Technology Research Center.The results showed that the net picking rate of ripe Chinese wolfberry was 96.13%,the damage rate of fruit was 1.13%,and the false picking rate was 3.23%,mechanized picking efficiency was 30.28 kg/h,which is 6.65 times that of manual picking.The experimental results are consistent with the simulation results.The research results can provide an important basis for the creation and operation standards of large-scale Chinese wolfberry vibration harvesting equipment.

Energy consumption mechanism simulation and experimental study of reciprocating vibration for Chinese wolfberry picking

In order to find out the matching principle of excitation force and energy consumption of reciprocating vibrating Chinese wolfberry picking device,the energy consumption mechanism of reciprocating vibrating Chinese wolfberry picking device is studied.According to the structural characteristics and operating principle of the picking device,the no-load and load movement and force characteristics of the crank bearing and vibrating component are analyzed,and the theoretical model of energy consumption of the reciprocating vibration picking device is jointly constructed,and the simulation analysis is carried out.The results show that the vibrating component and load mass have a significant influence on torque,the load air resistance phase has a significant effect on torque,and the load air resistance and friction coefficient have no significant influence on torque.Subsequently,by building an AC servo motor torque detection system and a torque sensing detection system,verification experiments are carried out,the maximum torque of the preset system is 1.3 N∙m,the rated power is 400 W,the motor frequency is 20 Hz,the amplitude is 15 mm,and the total mass of the vibrating component is 0.143 kg.Test results show that,the no-load operation,the change trend of detected torque is consistent with simulation,the torque model is verified to be accurate.The maximum torque of simulation and detection are 0.52 N∙m and 0.57 N∙m respectively,and the error between test and simulation is 9.6%.For load operation,the maximum torque of five groups of branch loads of 20 g,60 g,100 g,140 g,180 g and 220 g are detected to be 0.73 N∙m,0.74 N∙m,0.75 N∙m,0.82 N∙m and 0.83 N∙m,respectively,and the relationship model between load and torque is obtained by fitting.The research results can provide a theoretical basis which can configure a suitable motor in the reciprocating vibration Chinese wolfberry picking device with a certain load limit.