Research On Parametric Design Of Knee Protector Based On Reverse Engineering

Knee joint injury has become one of the most common knee diseases,induced by long-term strain,fatigue,and external violent impact,which can seriously damage the continuity and integrity of limb bones.Traditional prefabricated knee joint protectors are prone to incomplete adaptation after wearing,resulting in low comfort,poor auxiliary rehabilitation effects,and even secondary injuries.Therefore,wearing appropriate knee protectors correctly helps to maintain a good biomechanical environment for the knee joint.To address this issue,this article proposes a parameterized design method for knee joint protectors based on reverse engineering.With the help of reverse engineering technology,human knee joint data is transcribed and reconstructed,and a parameterized modeling program is designed to achieve personalized and customized rapid design of knee joint protectors.Finally,combined with comparative wear experiments and subjective and objective comfort evaluations,the effectiveness of knee joint protection design was verified.The main research work and content of the paper are as follows:(1)Knee joint shape reconstruction based on reverse engineering.With the help of reverse engineering technology,3D scanner is used to collect the original data of the knee joint,and the original data is preprocessed through Geomagic studio software.Further,NURBS curves and surfaces are reconstructed in the Grasshopper environment to obtain the morphological model of the knee joint,and the deviation analysis is completed,laying the foundation for the subsequent design of knee protection.(2)Parameterized design of knee joint protectors based on Grasshopper.Under the development environment of Grassshopper,a nonlinear automatic modeling program was designed and compiled,including NURBS curve,surface reconstruction module,protective device model shell segmentation module,protective device overall molding module and protective device topology optimization module.The left leg knee joint 0° and 30° knee joint protective devices were purposely established.According to the design requirements,with the goal of improving comfort,parameters were input to the region to quickly generative model.(3)Personalized customization and verification.This article proposes a comfort evaluation method for calculating the pressure distribution at the type value points of knee joint protectors.To address the issue of uneven pressure on the human body after wearing protective equipment,establish the pressure relationship between knee joint shape and protective equipment,construct a flexible knee joint protective equipment shape mapping curve,calculate the pressure distribution at key data points,and divide the pressure value into high,normal,and low areas.And use the fuzzy evaluation of AHP method to comprehensively quantify and score the protective equipment.Finally,a comparative experiment was conducted to compare and analyze the wearing of personalized customized knee protectors by participants with other prefabricated protectors,including factors such as fit,wearing convenience,wearing body surface temperature,and weight of the protectors,in order to verify the rationality and effectiveness of knee protectors.