Research On Key Technologies Of The Vibration Reduction Exoskeleton In Riveting Process Of Aircraft Assembly

During riveting work,aircraft assembly workers must hold the riveter by hand,which will produce continuous vibration impacts that may cause damage to the muscle and skeleton of assembly workers.In this paper,using the ergonomics design method,a kind of mechanical exoskeleton with spring-damped damper arm was developed for aircraft assembly workers based on the research in the field of aircraft assembly,which referred to some mature exoskeleton prototypes at home and abroad and Chinese human body size.Then,some feasibility studies of the key exoskeleton parts had been done about the lower limbs and the exoskeleton manipulator.Finally,the application feasibility of the aircraft assembly exoskeleton in aircraft assembly field was verified by some prototype tests.Firstly,the significance of application of exoskeleton in aircraft assembly field was proved based on the research of the work-related musculoskeletal diseases(WMSDs)and the characteristics of this field.In order to well develop the aircraft assembly exoskeleton which could alleviate WMSDs morbidities,various kinds of exoskeletons at home and abroad were investigated.After a professional investigation of the working conditions of riveting workers in an aircraft assembly workshop,some high-risk factors and five common kind of riveting postures in this work were found.Based on the research and analysis of workers and their working conditions,the exoskeleton design requirements and design goals were found.A mechanical exoskeleton with spring damper was developed in reference to these design requirements and goals,combined with human bionic design method.Then,based on the exoskeleton prototype model,the man-machine coupling model with double crank slider of exoskeleton was put forward,and it’s motion equation was established to verify theoretically the relationship between the working efficiency of exoskeleton lower limb and the length of legs.Through the dynamic simulation test with ADAMS software,the working efficiency of the lower extremity of exoskeleton under different conditions was obtained,based on which the ergonomic design method of the exoskeleton lower limb was put forward.Using the static balance system of spring linkage mechanism,this paper expounded the load-bearing principle of the mechanical manipulator,established the dynamic model of the single mechanical manipulator,and explained the vibration reduction principle of the mechanical manipulator.By using the dynamic simulation software ADAMS,the corresponding performance of the manipulator was verified and the load-bearing curve of the manipulator was obtained,so that a design method of the load-bearing performance of the manipulator was proposed.Additionally,the vibration simulation model of the manipulator was established,and the vibration damping performance of the arm was verified.The relationship between the damping coefficient of the manipulator damper and the force on the hand was obtained.Finally,Using the EMG measuring instrument and the pressure sensor,the objective tests were established,which results showed that,wearing exoskeleton for riveting could reduce the load by about 20% on average in both EMG signals and contact force,which proved the performance of this exoskeleton.Based on the NASA-TLX questionnaire,the subjective assessment tests were established to verify the performance of exoskeleton in human perception.Both subjective and objective evaluation tests showed that exoskeleton has good load reduction performance.