Performance Analysis And Design For Parllel Joint/Kinematical Unit Of Bionic Robot

With the development of technology, the bionic robots have been a hot spot of the robots research. The bionic robots can simulate the outside structure or the motion form of the living beings in the nature, and they are mainly connected by a series of joints or kinematical units. Design of the bionic joints and kinematical units is an important part of the study of the bionic robots. The robots are often designed in the serial structure while the serial structure has the disadvantages of low bearing capacity and weak stiffness. The parallel joints and kinematical units have overcome the disadvantages and they have compact structure and strong bearing capacity. In this paper, performance analysis and design methods of several parallel joints and kinematical units have been researched, and the corresponding prototype is developed.This paper has proposed the2-DOF orthogonal elbow joint kinematical unit and the3-DOF orthogonal shoulder joint kinematical unit. The elbow joint kinematical unit takes the5R orthogonal spherical2-DOF parallel mechanism as prototype. It has the advantages of flexible motion and strong bearing capacity. It can simulate the motion of human elbow, which can obtain the2-DOF rotation. The shoulder joint kinematical unit takes the3-RRR orthogonal spherical3-DOF parallel mechanism as prototype. It has the advantages of parallel mechanism. It has a strong stiffness and it's easy to manufacture and assemble. It can obtain the3-DOF rotation just like the human shoulder.The position positive and negative solutions formulas of elbow joint kinematical unit and shoulder joint kinematical unit have been established. The workspace of the two kinds of joint kinematical units and the effects on the size of workspace of the main structural parameters are given. The decoupling performance, dynamics and geometric errors are analyzed. The performance indexes are defined and the distribution of the performance indexes in the workspace is drawn. The geometric space model of the two kinds of joint kinematical units and the relation of the structural parameters and the global performances are developed, which build the theoretical foundation of the structural parameters design. With the application of the Monte Carlo parameters selecting method based on global performances atlas, a series of structural parameters are given when taking the manufacturability of manufacture and assembly into consideration. By using the parameters we got, the two kinds of joint kinematical units are designed and the prototypes of the two kinds of joint kinematical units are developed successfully.This paper proposed a novel leg kinematical unit which has three branches of6-DOF, which used3-UPS parallel mechanism as the prototype of the mechanism. The mechanism has a symmetrical structure, which has the advantages of good stiffness, high load capacity and good dynamic performance. The positive and negative solutions formulas are built. The workspace, statics, dynamics and other issues are analyzed. The paper established the kinematical unit's performance evaluation indexes, and presented the effects of performance evaluation on the workspace. The leg's kinematical unit's global performance index is defined. The paper used space model theory to design the leg kinematical unit's structure parameters, and selected the kinematical unit's structure parameters. The virtual prototype of leg kinematical unit has been designed.A novel6-DOF hybrid humanoid arm is proposed. The arm's shoulder, elbow and wrist joints respectively using3-DOF orthogonal shoulder joint kinematical unit,2-DOF orthogonal elbow joint kinematical unit and four-bar linkage. These constitutes a"3-2-1" layout. The mechanism has the advantage of flexible motion and good stiffness, which can realize the function of humanoid arm. In this paper, a kind of bionic four-legged walking robot is designed. The robot with four mechanical legs which used three branches of6-DOF leg kinematical unit. The walking robot has the advantages of compact structure, high load capacity, and good stability.