Analysis of Kinematics and Design of Structure Parameters for a Bionic Parallel Leg

This paper proposed a novel bionic walking leg which has three branches of 6-DOF, using 3-UPS parallel mechanism as the prototype, it has good advantage of compact structure and strong bearing capacity. Kinematics research of mechanism is very important, the dynamic analysis and the design are based on kinematics analysis. And the kinematics performance of the bionic walking leg is analyzed and the structure parameters are optimized. First, the kinematics transmission equation of the bionic walking leg is established, and using the norm theory the kinematics performance evaluation indexes are defined, and kinematics characteristics are analyzed. Then, application space model theory the structure parameters of the bionic walking leg are designed, and using of the Monte Carlo parameters selecting method based on the global kinematics performance atlas, the optimal structural parameters are given. Analysis results show that kinematics transmission performance indexes display the symmetric distribution of the bionic walking leg, the static platform radius is 120mm, moving platform radius is 50mm, and the height of the static platform and moving platform initial posture is 700mm. Finally, using the optimal structural size parameters, the virtual prototype of the bionic walking leg is designed. So,it has very important significances of theory and engineering to study and open out parallel mechanisms as the leg mechanisms of bionic walking legs.