Mechanism Design And Global Analysis Of Agile Bionic Legs

The agile bionic leg has many advantages,such as smart mechanism design,light weight,small inertia,high efficiency,simple control,agile motion and outstanding jumping performance.Therefore,it has attracted extensive interest of researchers at home and abroad in the field of high-speed bionic robots and jumping bionic robots,and has gradually developed into a new research direction.In the research of the agile bionic legs,there are two problems that need to be solved urgently:(1)The configuration of the agile bionic legs is not abundant enough and the design criteria is not clear enough,so it is urgent to carry out innovative design of the configuration and propose clear design guidelines;(2)When the number of connecting rods is more than 4,the global scale analysis method and theory of the motion performance of the agile bionic leg mechanism are not perfect,so it is urgent to put forward a universal global analysis method and theory.This paper focuses on the above two issues to carry out relevant research.The main contributions and innovations are as follows:1.The concept of agile bionic leg is put forward clearly,and the design criteria is offered.According to the design criteria,typical single-degree-of-freedom agile bionic leg configurations with 4,6 and 8 bars are given.These configurations belong to planar single-ring or multi-ring linkage mechanisms.Taking 8-bar single degree-of-freedom mechanism as an example,the feasibility of the agile bionic leg mechanism and design criteria was preliminarily verified by the simulation analysis of virtual prototype and the development of experimental prototype.In order to fully tap the application potential of this kind of bionic leg mechanism,multi-level optimization and innovative design were carried out.2.Aiming at the characteristics of planar linkage mechanism with agile bionic legs,the method and theory of global characteristic analysis of mechanism motion performance is put forward by using modern mathematical theories such as singularity theory,low-dimensional manifold topology and group theory.The core contents of this method are as follows:based on the abrupt change of the topological structure of the solution space,the classification method of the scale of complex mechanisms is studied;based on the singular partition of the solution space,the global structure distribution characteristics of the mechanism performance are studied;and based on the abrupt change of the solution space partition,the morphological evolution of the mechanism motion performance distribution is studied.3.Taking the six-bar double-ring bionic leg mechanism as an example,the global analysis of the kinematic performance of the mechanism is carried out.The process of theoretical analysis shows that the method is suitable for the global structure analysis of planar bionic leg mechanisms with arbitrary single-ring or multi-ring linkages.By comparing the conclusion of the global structure analysis of four-bar linkage with the classical Grashof criterion,the correctness of the theory of this method is verified.This method is conducive to grasping the evolution law of the motion characteristics of the mechanism as a whole,and expanding the vision of the analysis and comprehensive design of the agile bionic leg mechanism.It provides a new analytical method and theory for enriching the innovative design and global characteristic analysis of agile bionic leg configuration.This method has strict mathematical basis and will provide theoretical basis for computer programming to realize the global characteristic analysis of the motion performance of arbitrary linkage mechanism.4.Using this method,the scale of six-bar agile bionic leg mechanism with single degree-of-freedom is designed,and the agile bionic leg is applied to the design of biped or quadruped robots.Through virtual prototype simulation and physical prototype experiment,it is proved that this kind of robot has the advantages of fast running,agile jumping and simple controlling.The experimental results further validate the effectiveness and correctness of the agile bionic leg mechanism and its global scale analysis method.