Design And Research Of Anti-vibration Exoskeleton For Upper Limbs Of Hand-held Vibration Tools

High-level and high-skilled technical application talents are the key factor to implement the "Made in China 2025" plan and accelerate the transformation and upgrading of manufacturing industry.At the same time,hand-transmitted vibration is widespread in the high-end manufacturing sector,as represented by aviation manufacturing,affecting occupational health levels.Long-term exposure to hand-transmitted vibration can easily lead to Hand-Arm Vibration Syndrome(HAVS),reducing workers’ concentration,productivity and,in severe cases,their ability to work and live,resulting in a brain drain of senior skilled workers.Industrial human augmentation systems such as industrial exoskeletons redefine the humanto-tool relationship and enhance the physical strength of workers to meet the needs of manufacturing development.However,existing research focuses on reducing tool load and ignores the impact of vibration on human body.Therefore,this paper combines the results of previous research to design a set of vibration-resistant exoskeleton for upper limbs with vibration reduction and tool support functions as an intervention to reduce vibration injuries and increase sustainable workability.The main work of the paper is as follows.First,to introduce the hand-transmitted vibration hazards in the context of manufacturing transformation and the current prevalence of hand-arm vibration syndrome in the field of aviation assembly,and to show the necessity of developing vibration-resistant exoskeletons according to the shortage of skilled workers and the aging national situation of the workforce in China.The research status of hand-transmitted vibration interventions is investigated,the advantages and shortcomings of existing research are summarized,and the design of exoskeletons with vibration damping,lightweight,comfort,and tool support functions is proposed to be significant.Secondly,the exoskeleton structure design guidelines are proposed by analyzing the operating conditions and human motion mechanism,and the exoskeleton structure is designed based on the ergonomic theory with the shear vibration damping unit as the core.The parameters of the exoskeleton structure are selected based on the principles of maneuvering comfort and functionality,and the simulation model of man-machine coupled maneuvering comfort evaluation is established based on the NASA force model,and the damping coefficient and spring stiffness are selected.Then,the kinetic theory analysis of the human-machine coupled system after wearing the exoskeleton is carried out according to the Lagrangian principle,and the key parameters affecting the system performance are summarized.ADAMS is used to establish a local parametric human-machine coupling simulation model according to the law of motion of the connecting rod of the shear damping unit,analyze the vibration response characteristics of the nonlinear system with variable excitation single-factor variation,obtain the response curve of the factor and force transfer rate,sweep the frequency to observe the vibration response of the system in the frequency domain,and analyze the vibration isolation performance in the working frequency domain.Again,the human-machine coupled simulation model is used to analyze the full-factor interaction,and the parameters that significantly affect the vibration damping performance of the exoskeleton and the interaction terms are obtained.The interaction orthogonal simulation test is designed based on the interaction analysis results,and the nonlinear regression analysis is performed based on the test sample data.The genetic algorithm is used to combine the regression results to optimize the structure of the shear vibration damping unit.Finally,a physical prototype of the exoskeleton is piloted and an objective test program is designed to simulate the real operating environment.Combined with the hand-transmitted vibration measurement and evaluation technical standards,the two-dimensional objective evaluation method of contact pressure and acceleration is proposed,and the experimental data are processed in the time and frequency domains using frequency weighting to examine the exoskeleton performance.The test results show that the exoskeleton can reduce the daily contact vibration value by 15.1%,and the single-day riveting efficiency is increased by 18%at most.The contact pressure during the riveting period was reduced by approximately 39.9%,and the intermittent period was reduced by 49.4%.The exoskeleton can reduce the gap between the vibration strength of rivet guns operated by workers with different levels of experience and improve riveting quality.