Optimized Design Of Five Degrees Of Freedom Hybrid Robotic Arm For Forest Fruit Loading And Unloading

Forestry and fruit industry is an important part of modern forestry,and the rapid development of forestry and fruit industry not only provides a channel for farmers to get rich,but also plays a certain role in promoting social and economic development.China grows a wide variety of forest fruit species,a huge number of products,is a large country of production and consumption of forest fruits.At present,the loading and unloading process of forest fruits after picking and sealing and express transit,mostly rely on manual,simple mechanical tools or semi-mechanized equipment,resulting in low efficiency,high cost and labor intensity of forest fruits loading and unloading.Therefore,it is imperative to design a mechanism for automatic loading and unloading of forest fruits.Therefore,this paper designs a five degree of freedom hybrid robot arm for forest fruit loading and unloading,establishes the kinematic theoretical model of the hybrid robot arm and ADAMS simulation model,and carries out the comparison and verification of the two models;then uses the improved sparrow algorithm to plan the optimal time trajectory of the hybrid robot arm;finally establishes the parametric model of the hybrid robot arm,and carries out the multi-objective analysis of the structural parameters of the hybrid robot arm.The multi-objective optimization of the structural parameters of the robot arm is carried out to improve its comprehensive performance.The main work of the thesis is as follows:(1)According to the requirements of forest fruit loading and unloading operation,the structure of the hybrid robot arm for forest fruit loading and unloading is designed,and the forward and inverse kinematic theoretical models of the hybrid robot arm are established based on the flush transformation theory using the standard D-H parameter method,and the workspace of the hybrid robot arm is analyzed using the Monte Carlo method,and the workspace of the hybrid robot arm is verified to meet the operational requirements.(2)The joint simulation model of ADAMS and MATLAB was established to verify the correctness of the theoretical model of the hybrid robot arm in forward and inverse kinematics,and the dynamics simulation of the hybrid robot arm was carried out to compare and analyze the moments of each driving joint under no-load and loaded conditions.(3)Five trajectory planning methods for the hybrid robot arm in Cartesian space and joint space are investigated,focusing on five polynomial,seven polynomial and seven Bsample interpolation trajectory planning in joint space,and the motion parameter profiles of the three methods are compared and analyzed.(4)To address the shortcomings of the sparrow search algorithm(SSA),an improved sparrow search algorithm(ISSA)is proposed,and the trajectory optimization of the hybrid robotic arm is carried out using the ISSA algorithm with the running time of the hybrid robotic arm as the objective function,and the results show that the running time of the hybrid robotic arm is greatly reduced,which verifies the effectiveness and superiority of the improved algorithm.(5)The ADAMS parametric model of the hybrid robot arm is established,and the multiobjective optimization design of the hybrid robot arm is carried out by using ADAMS/Insight module with the optimization objectives of reducing the drive joint torque of the large arm parallel mechanism and the acceleration of the end-effector of the hybrid robot arm,and the peak and average values of the acceleration of the end-effector of the hybrid robot arm are reduced by 4.676%and After optimization,the peak and mean values of acceleration of the end-effector of the hybrid arm were reduced by 4.676%and 16.21%,and the peak and mean values of driving torque of joint 3 and joint 5 were reduced by 59.32%and 6%,respectively,and the mean values were reduced by 36.12%and 5.91%.