The Statics Research Of Robot Hip Based On 3-dof Parallel Mechanism With Center Sphercal Pair

Humanoid robot is the highest stage in the development of robots that imitat the structure, the movement principle and the behavior way of biological in nature. The research of joint is an important aspect in the field of humanoid robot research, the standards of robot joint performance directly determines the quality of the overall performance of robot.This article combined with the feature of hip joint structure, movement and body functions, for its prototype body mechanics problems of 3 RRR,and its requirements of static discharge and increasing the line displacement stiffness, coming up with a new type of 3-dof spherical parallel bionic hip joint mechanism with center spherical pair that highly similar in the appearance of human hip joint structure, the movement way and its bearing capacity from the perspective of bionics, and then makes a deep study of its mechanical performance; on this basis, we design a new bionic hip bionic hip mechanism with offset output. This article provides a certain theoretical basis for the further research of humanoid robot joint.Expounded the principle of the architecture of the hip, movement and its motion form; conducted static analysis and evaluation for the bionic prototype mechanism of hip joint, presented a new type of 3-dof spherical parallel bionic hip joint mechanism in order to solve the flaws of the prototype body,and analysis its degrees of freedom.The statically indeterminate statics of the new spherical parallel bionic hip mechanism was finished. We got the mechanism’s statics complete solution by all of the static equilibrium equation and deformation coordination of supplementary equation that using the small deformation superposition principle considering the elasticity of the component.Obtained all graphs that present the relationship between the force,moment, input torque on every component and the external load, body position of the mechanism under its actual parameters. The new mechanism has better mechanical performance and stiffness compared with its prototype mechanical, which lays the foundation for the design and application of the mechanism.Put forward the new idea of offset output for the mechanism according to the requirement of the human hip joint working space. Based on the kinematics reverse solution of spherical parallel mechanism with 3-DOF and the space mapping between the output of the human body and mechanism, we obtained the kinematics reverse solution of spherical parallel bionic hip mechanism with offset output.