Design For Shoulder Elbow Wrist Joint And Arm Of Humanoid Robot

In this dissertation, the shoulder elbow wrist joint and arm of the humanoid robot are studied, including the kinematics performance and design method etc.. The following work has been achieved.A novel 7-DOF hybrid humanoid arm is proposed, which is composed of 2-DOF wrist joint, 2-DOF elbow joint and 3-DOF shoulder joint. The shoulder joint based on the orthogonal spherical 3-DOF parallel mechanism is designed, and the elbow joint and the wrist joint based on the orthogonal 2-DOF parallel mechanism are designed respectively. The three joints are connected in series. The humanoid arm has the advantages of parallel mechanism and series mechanism. It has the good performances in operating range, the bearing capacity and the movement flexibility etc..The inverse position equation of the shoulder joint mechanism is established, and the selection criterions of the inverse solution are given. Based on the inverse kinematics equations with constraint conditions, the workspace of the shoulder joint mechanism is drawn with three dimensional boundary searching method. The number of points in the search space under the fixed step size is used to evaluate the workspace. The influence of structural parameters on the workspace is discussed. The kinematics equation of the shoulder joint mechanism is established, and the performance evaluation indexes of the mechanism kinematics are defined, and the distribution of the evaluation indexes in space are drawn and analysized. The Lagrange method is used to establish the dynamic relationship model between the driving torque of the shoulder joint mechanism and the motion parameters of the system, and based on the dynamics model, the variations of the dynamics parameters are given. The genetic algorithm is used to find a set of optimal mechanism parameters of the shoulder joint mechanism, and the prototype of the shoulder joint is designed based on the parameters and technics.The position equation of the elbow joint mechanism is built, and the workspace performance index is defined. Based on the constraint conditions, the workspace of the eldow joint mechanism is drawn. The influence of structural parameters on the workspace is analysized. The velocity and acceleration equations of the elbow joint mechanism are established, and the Jacobian matrix and Hessian matrix are deduced by using the influence coefficient method. The velocity and acceleration are defined as the evaluation index of the mechanism, and the performance evaluation indexes of the mechanism in workspace are analysized. The dynamic model of elbow joint is established by using Lagrange method, and the dynamic characteristics of the elbow joint mechanism are studied. Based on the global performance evaluation indices, the optimization design model of the elbow joint mechanism is established. The genetic algorithm is used to find a set of optimal mechanism parameters of the eldow joint mechanism, and the prototype of the eldow joint is designed based on the parameters and technics.A novel wrist joint mechanism is proposed, its position equation is deduced, and the workspace of the mechanism is drawn. The influence of structural parameters on the workspace is analysized. The velocity and acceleration equations of the wrist joint mechanism are established, and the performance evaluation indexes of the mechanism are defined, and the distributions of the evaluation indices in workspace are presented. Based on the global performance evaluation indices, the objective optimization design model of the wrist joint mechanism is established, then the structure parameters of the mechanism are optimized by genetic algorithm, and the prototype of the wrist joint is designed based on the parameters and technics.The forward and inverse position solutions of the redundant anthropomorphic arm with 7 degrees of freedom are obtained by geometric method, and the kinematics equation of humanoid arm is deduced. The inverse kinematics solutions of the redundant humanoid arm are presented with the gradient projection method. The speed relation between the end of the humanoid arm and the joint angle is discussed. At last, the simulation experiment is carried out by using the tri-polynomial interpolation.