Analysis Of Vibration Reduction Mechanism And Optimization Of Structural Parameters Of The Wearable Anti-vibration Exoskeleton

“Mechanic Shortage”is a common problem in China’s manufacturing industry,and the shortage of skilled workers has hindered the transformation of China’s manufacturing industry.What’s more,the problem of“Mechanic Shortage”is exacerbated by the Work-related Musculoskeletal Disorders（WMSDs）of workers.Therefore,the industrial exoskeleton is introduced to protect the manufacturing companies existing skilled workers by many scholars.At present,most of the research on industrial auxiliary equipment focuses on reducing the load of human body,but ignores the harm of vibration to workers when operating power tools.In view of this,a wearable anti-vibration exoskeleton considering both the tool holding and vibration absorbing is designed in this paper,which protect the skilled workers and reduce the absenteeism and demission caused by WMSDs.And it is introduced into the riveting process of aircraft assembly industry to analyze its anti-vibration mechanism and optimize its structure.The main work of this paper is as follows:First of all,introduce the problem of“Mechanic Shortage”in China’s manufacturing industry,the harmfulness of manual operation and the status of WMSDs of skilled workers in aircraft assembly industry to show the importance of designing industrial auxiliary equipment.Investigate the research progress of industrial exoskeleton and anti-vibration equipment to analyze the advantages and disadvantages of the existing researches.The wearable anti-vibration exoskeleton with both the tool holding and vibration absorbing was proposed,and on its application in riveting process was studied.Secondly,the overall structure and upper extremity model of the wearable anti-vibration exoskeleton were introduced.The working condition of the wearable anti-vibration exoskeleton assisting riveting was analyzed as the single-degree-of-freedom nonlinear man-machine coupling vibration model.Its dynamic model was established based on the Lagrange principle,which obtained the system motion differential equation and its characteristics.The reverse simulation method is proposed based on ergonomics to obtain the equivalent stiffness and damping of the human arm.The first-order harmonic balance method was used to solve the system motion differential equation to calculate the analytical solution of the steady-state response of the system and obtain the vibration characteristics of the system under different parameters and vibration excitation.Thirdly,design the riveting test of vibration reduction performance of anti-vibration exoskeleton by simulating the aviation assembly riveting process.A weighted average method was proposed to comprehensively evaluate vibration reduction performance of the exoskeleton by means of the mean of pressure signals in different postures during riveting period and riveting interval period when wearing or not wearing the anti-vibration exoskeleton and the weight coefficient of postures.The test results show that the wearable exoskeleton can reduce the vibration of riveting gun by more than 50%and has an important protective effect on the arm of assembly workers.Finally,the structural parameters of shock absorber were optimized by Orthogonal test method.Based on the human-machine coupled mathematical model and the exoskeleton prototype parameters,the 5 factors and 4 levels orthogonal simulation test is designed according to the standard orthogonal table L₁₆（4⁵）.The test results have reduced the force transmissibility T_f by 68.9%,and determined the significance ranking of the influence of structural parameters on the vibration reduction performance.