Design And Optimization Of A Passive Hip Assisted Exoskeleton Based On Ergonomics

At the modern production line,employees need to engage in manual handling,and the incidence of lower back pain increases gradually.In order to avoid occupational lower back pain,domestic and foreign institutions have studied and developed various wearable waist protection devices.These devices mainly help the hip or spine joints,thereby reducing waist muscle damage.At present,the research of hip joint assistant exoskeleton mainly focuses on its mechanical structure,labor saving degree and so on,but neglects that the exoskeleton’s range of activity should conform to the user’s actual working range.This paper analyzes and designs a passive hip four-degree-of-freedom assisted exoskeleton from the angle of ergonomics,which not only helps users to reduce hip force during handling work,but also increases the range of hip abduction/adduction.The range of motion is extended from one-dimensional space to two-dimensional space,which increases the comfort of the device.Firstly,the present situation of hip joint assisted exoskeleton at home and abroad is analyzed,the passive pure mechanical structure is selected,and the biomechanical analysis of bending movement is carried out in combination with human anatomy.The working principle is analyzed to determine the feasibility of labor-saving structure.Then according to the relevant theory,the key parts of exoskeleton are selected to determine the maximum labor saving degree of exoskeleton.Secondly,according to the theory of ergonomics,the design of humanized size,wear mode and hip joint range is carried out to improve the wear comfort of the device.By ADAMS dynamics simulation,the change of torque of hip joint is analyzed to verify the labor saving degree of the three materials selected,and the strength of the three materials is analyzed by statics.Then the labor saving degree of the device under different working conditions is studied,and the labor saving range of the device is obtained.CATIA man-machine engineering module is used to analyze the comfort of the human body when the hip joint is moved in two or four degrees of freedom.The lightweight design of hip joint structure is carried out by topology optimization to reduce the weight of the device.Finally,combined with the concept of industrial design aesthetics analysis to summarize the aesthetic criteria of exoskeleton modeling,combined with the existing exoskeleton product modeling analysis,summed up the characteristics of exoskeleton modeling design,and obtained the modeling scheme.The final design of the hip exoskeleton scheme is more prominent in both aesthetic and structural properties.The device saves about 63% labor when carrying 5 kg～25 kg of heavy objects,and has high comfort.It provides an effective scheme for subsequent exoskeleton research.