Research On Mechanical Picking Vibration Characteristics Of Blueberry Plants And Design Of Picking Experiment Bench

In recent years,China's blueberry industry is booming,and the planting area of blueberry is increasing year by year.Blueberry fruit ripening period is short,labor intensity is high,labor cost is high,artificial harvesting efficiency is low,harvesting is not timely is the major problem facing the industry,resulting in huge economic losses and resource waste.The research on the vibration characteristics and vibration theory of blueberry plants is of great significance to improve the blueberry harvester design and promote its application.This paper analyzes the principle of blueberry plant vibration picking,establishes blueberry plant vibration model according to the plant growth form,transforms the vibration model to get the output response under different vibration states,and solves the picking force of fruit according to the output response.The response curve under the condition of free vibration of plant was collected by the sensor acquisition system,and the basic frequency and damping ratio of plant were calculated according to the displacement curve of free attenuation vibration of plant.Analyze the spectrum characteristic curve formed by processing,determine the resonance frequency of the plant within the reasonable frequency range of blueberry picking,study the harmonic frequency points of the spectrum curve of the plant in three directions of the same measuring point,and obtain the amplitude performance under different frequencies.Based on the analysis of the blueberry picking operation form and the design requirements of the picking machinery,a kind of blueberry picking vibration experimental platform was designed.Compared and designed the picking mechanism of the experimental platform with the mobile device of the experimental platform,analyzed the selection of key components,checked the strength and fatigue strength of dangerous components,and completed the construction of the experimental platform.Using the orthogonal test method to combine the working parameters of the experimental platform,aiming at the comparison of blueberry vibration output response and the best picking exciting force response range and the actual picking effect,the orthogonal test is carried out.Through the experimental analysis,the impact degree of different mechanical parameters on the vibration output response is obtained.At the same time,the best design parameters satisfying the picking conditions are found through the comparison.Combining the self built experimental platform with the sensor acquisition system,the blueberry plant vibration experimental test system is established,and the plant branch measuring points are defined.The acceleration response of each measuring point is monitored by the sensor,and the forced vibration response characteristics of blueberry plant under different excitation frequencies and the distribution and transmission of vibration response in each branch are studied.The mathematical relationship is used to a certain extent Express the change trend of acceleration with vibration frequency.Through the acceleration transfer ratio to study the transfer law of the vibration energy of the internal and external branches,we can get the law that is conducive to improving the transmission efficiency of the vibration response.The research results of this paper provide a theoretical basis for further study on the spectrum characteristics,vibration response,modal shape and the establishment of more accurate dynamic model of blueberry plants,and provide a certain parameter reference and design reference for the development and improvement of blueberry picking machinery.