Research On The Design And Stability Of Bio-inspired Foot Mechanism Based On The Tensegrity Structure

Whether human is walking on a flat ground or on a slope,they can remain stable without falling,which shows the self-stable structural characteristics of the human foot.The foot structure is summarized through structural simplification and movement characteristics,combined with the characteristics of small mass,low inertia,good flexibility,and foldability of the tensegrity structure,which achieves the purpose of adapting to complex ground and compliant walking.Although the tensegrity structure has the advantages of flexibility,safety,and adaptability,the rigidity of the flexible mechanism is poor,and it is not easy to maintain a stable state when external force is applied.Therefore,the design and addition of the locking mechanism play an important role in the stability of the foot mechanism.Based on the similarity between the tensegrity structure and the human musculoskeletal system,a bionic foot locking mechanism is proposed to improve the stability of the traditional foot robot.Through the extraction of the motion characteristics of the human foot ankle joint and the simplified morphological structure,a simplified biological function mapping model is established,and a locking mechanism is constructed,which is added to the flexible tensegrity structure to realize the flexible locking of the mechanism.Based on the theory of mechanism and bionics,this paper analyzes the characteristics of human foot movement and biological structure,and organically combines the flexible tensegrity structure with the locking mechanism.Then complete the bionic foot mechanism design with adaptive terrain and stable locking function.The main content of this paper includes the following parts:(1)The structural characteristics and movement characteristics of the human ankle joint.Based on the relevant theories of bionics,extract the structural characteristics and movement characteristics of the human foot and ankle joints,and analyze the stability principles of the foot and ankle joints.(2)The coupling of flexible mechanism and rigid mechanism.The configuration-related size determination and stability analysis of the bionic foot with the flexible tensegrity structure are carried out,and the rigid locking mechanism is designed according to the locking mechanism of the ankle joint of the human foot.The tensegrity structure is coupled with the locking mechanism to obtain a bionic foot mechanism.(3)Motion simulation and stable configuration design of the mechanism.The motion simulation of the bionic foot mechanism with locking function is carried out using ADAMS to verify the adaptability and stability of the mechanism.On this basis,by changing the spring arrangement of the mechanism,a stable configuration of the bionic foot mechanism is obtained,and the 3D model of the mechanism is drawn using Solid Works software.(4)Manufacturing,assembly and testing of physical prototypes.The physical prototype is manufactured through 3D printing technology,and the assembly and debugging of the mechanism are completed according to the model drawing drawn by Solid Works.Experiments are carried out to verify the adaptability,stability and self-recovery ability of the bionic foot mechanism,and to test the ability of the bionic foot mechanism to walk stably.Using the biological structure of the human foot as a bionic template,based on bionics and mechanism theory,the tensegrity structure and locking mechanism of the bionic foot are obtained.Through rigid-flexible coupling,the design of a bionic foot stabilization mechanism with stability and adaptability is realized,which is used to solve the problems of poor adaptability to terrain and unstable ankles of humanoid robots during walking.