The Bionics Design Of Humanoid Robot Shoulder Based On Spherical Parallel Mechanism

The humanoid robot, which is imitating the whole or individual elements of human, notonly mark the comprehensive level of national high-tech development, but also widelyused in human productions and livings. As the joint possessing the largest motion range,the shoulder complex is key in humanoid robot research fields, and has receivedincreasing attention of more and more foreign and domestic scholars. This paper conductsa serial of researches concerning the bionic shoulder complex mechanism based on thespherical parallel mechanism (SPM), which lay the foundations for the development andapplication of the bionic parallel mechanism. The research contents of this paper are asfollows:The composition of the shoulder complex, the functional characteristics of the shouldermuscles and the motion principle in anatomic are systemically introduced. Then thefundamental theory and the recent research of the shoulder complex are analyzed. Thesignificance and development direction of the shoulder bionics are explored.In order to compare analysis the integrative characteristic of SPM for the shoulder, theclassification of SPM is sorted. Based on the structure characteristic and motion principle,the optimal selection of the spherical parallel mechanism for the shoulder complex isperformed, and then the preferred3-PSS/S SPM for shoulder is preliminary synthesized.Kinematics analysis is presented for3-PSS/S SPM， which is taken as the protomodelof the human joint. Combined with the constraints of mechanism, the position inversesolution by analytical method is deduced; and the orientation workspace is drawn usingMatlab software. The influence of the structure parameters on the workspace is analyzedby single-variable analysis method. The spherical hinge with multi-ears and the offsetshank are introduced into the protomodel, which can free the rotation of the movingplatform around its own axis, and change the output direction of the workspace. At last,the transformation matrix of the SPM with offset shank is constructed relative to the worldcoordinate system of the human body.The intelligent optimization of values of the structure parameters and performance optimization tracking graph are obtained by genetic algorithm, which realized thevisualization of the genetic processes, then the effectiveness of the optimization result isverified by reverse authentication method.According to the mechanical processing technology, kinematic analysis andoptimization results, the3-PSS/S SPM of the bionic shoulder is designed. Based on the3Dmodel and engineering drawing, the spherical hinge with multi-ears is built, and theprototype model of the bionic shoulder mechanism is established.