Research On The Performance Of The Executive Mechanism For Picking Asparagus

In order to solve the problems of farmers manually breaking reed shoots in Yuanjiang City,Hunan Province,the working hours are concentrated,the work intensity is high,and the efficiency is low,which seriously restricts the development of the reed shoots industry in the city,and fills the research gap of reed shoots harvesting technology at home and abroad.The research group independently developed a reed shoot picking actuator based on the principle of clamping the reed shoot stalk with a flexible double synchronous belt to generate a breaking force,breaking it off and transporting it.In order to simulate the action process of manually picking reed shoots,a picking actuator including a tail cutting device,a breaking conveying mechanism and a lifting mechanism was designed;the force and speed of the breaking mechanism were analyzed to match the required hydraulic power;the software AN SYS-Workbench and software ADAMS simulation to verify the rationality of the design of the power takeoff shaft and the conveying stage of the breaking conveying mechanism;Based on the Box-Behnken principle,the mechanism test plan was designed,and the response surface comprehensive optimization test method was used to obtain the optimal combination of the mechanism’s harvest test factors and the comprehensive optimal value of the test indicators.The specific work is as follows:(1)Starting from the collected experimental data on the properties of reed shoots,design the structure of the components of the picking actuator.The physical and mechanical properties experiments of stems collected the shape data such as plant height and stem diameter,as well as the mechanical data of stem breaking force and cutting force.The mathematical statistics method was used to perform linear fitting regression analysis on the force and stem diameter.The structural composition scheme of the picking actuator is proposed,and the key components are structurally designed:the design of the belt drive of the tail cutting device,the design of the power input shaft of the breaking conveying mechanism,and the design of the adjustable range of height and angle of the lifting mechanism.(2)Mechanics and velocity model analysis and simulation verification of breaking conveying mechanism.The relationship between the stalk clamping force,breaking force,clamping force,and spring force was analyzed.Based on this,the working parameters of the tension spring and the diameter of the synchronous belt pulley were designed,and the driving force of the synchronous belt was analyzed to be 1155.85N.Using the velocity synthesis and decomposition vector method of the movement speed of the stalk of the reed shoots,the forward speed of the whole machine and the movement speed of the synchronous belt,the ideal range of parameters and the theoretical power of the picking actuator are obtained,and the GM5-6 hydraulic motor is matched.The software ANSYS-Workbench analyzes the power input shaft,and the values of its parameter cloud diagram are all smaller than the theoretical analysis value.The software ADAMS establishes the model of the breaking conveying mechanism and the stalk model of reed shoots,and sets the theoretical parameters.The simulation results show that the theoretical analysis is correct.(3)Harvest test and optimization to obtain the comprehensive optimal value of the performance index of the mechanism.Taking Box-Behnken as the principle to design the mechanism’s harvesting test scheme,the response surface analysis method expounds the interaction effect of multiple test factors on the test indicators,and the combination of software optimization of test factor combination and test verification is obtained::The movement speed of the synchronous belt is 2.9m/s,the inclination angle of the mechanism is 36.8°,and the forward speed of the whole machine is 1.2m/s.The comprehensive best value of the test indicators:the picking rate is 93.54%,and the damage rate is 5.99%.