| The research object of this paper is the claw-type manipulator device of the side-mounted garbage collection truck.The manipulator is an important component in the garbage collection and transportation vehicle,and its main function is to complete the grabbing,retracting,lifting,flipping,dumping and returning to actions of the trash can.According to the established technical requirements and functional objectives of the project,the total assembly model,virtual prototype model,finite element model and parametric model of the manipulator has established.The kinematics and dynamics simulation analysis of the manipulator,static finite element analysis,modal analysis and structural optimization design has carried out.The main contents of this article include:(1)The formulation of the manipulator structure plan,geometric modeling and working principle analysis.According to the established technical requirements of the side-mounted garbage collection vehicles and relative required functional objectives,the structural characteristics of the garbage cans commonly used in the market and the modified garbage trucks,the design of the manipulator has been determined.Based on the actual engineering situation,the two sets of schemes are compared and ana lyzed.The final manipulator scheme has determined.The geometric model of the manipulator is established.The working principle of the manipulator structure is analyzed.Finally,the accuracy of the trajectory are verified.(2)Robot kinematics and dynamics simulation.The virtual prototype model of the manipulator was established by Adams software,and the dynamic characteristics simulation analysis was carried out.The trajectory of the centroid of the gripper structure is studied,and the displacement and velocity curves has been obtained.By analyzing the dynamic characteristics of the lift arm and the flip arm,the force and torque of the hydraulic cylinder,it is found that the movement of the robot is lifting and the ram is retracted.When the three working conditions are started,the force and torque appear to be slightly abrupt.It is believed that there is a certain vibration and impact in the robot system.(3)With static finite element analysis,typical working conditions of manipulator structure has been analysed.Using the Workbench to build a manipulator finite element model,by analyzing,the position of maximum stress and deformation of the manipulator structure has been found the structure is affected by the stress concentration and the maximum deformation occurs at the foremost end of the left hand of the manipulator,and the maximum stress is at the joint of the robot arm and the piston base of the lift cylinder.The maximum stress was at the joint of the robot arm and the piston base of the lift cylinder.The maximum stress under all three conditions is within the allowable yield strength of the material,indicating that the strength and stiffness of the structure meet the design requirements,which proves that the design is feasible.(4)Manipulator structure modal analysis and lightweight design.In order to study the vibrational shape characteristics of the structure,the modal analysis of the manipulator structure is carried out.According to the analysis,the natural frequency values of the first 6 modes of the structure deviate from the excitation frequency,so no resonance phenomenon occurs.Based on the results of static finite element analysis,the bucket conditions with the largest stress and maximum deformation are selected as objects of the lightweight research.The manipulator optimization model has established,and the structural optimization calculation are carried out.By comparing with the finite element analysis data before the optimization of the working condition,the overall quality of the manipulator is reduced,and the quality is reduced by 12.28%,which achieves the expected effect of lightweighting to a certain extent,and provides a reference for further optimization of the manipulator. |
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