Study On A Bio-Inspired Foot Locomotion Mechanism For Biped Robots

A biped robot is a robot with its overall appearance close to human being, thekey technology is biped walking and the most important features are walking likehuman and completing the basic locomotion function. Although a lot of achievementshave been gotten in the field of humanoid robot, there is still a challenge in how toimprove its stability and flexibility of gait, locomotion speed and autonomous inworking. Because the feet are the only mechanism which is in touch with the grounddirectly and gets the reaction, it is clear and extremely important that the study of thetouch procedure and the damping techniques for minimizing the impact force. Thispaper discusses mainly the bio-inspired foot locomotion mechanism for biped robotsand the resear work is organized as follows:1. Analyzing the purpose and significance of researching on foot joints of bipedrobot, generalizing advantages and disadvantages for many kinds of foot mechanism,generalizing the study at home and abroad, from the aspect of bionics, proposing it'spossibility that designing foot mechanism using compliant mechanisms.2. Combining the knowledge of anatomy, mechanics of human motion, bionics andcompliant mechanisms, analyzing the structure and motor function of every part, suchas skeleton, muscle; According to the research of walking gait,analyzing footmechanism in the respects of impacting, damping and energy storage, which providesbasic reference for the further study of bionics flexible energy feet.3. According to locomotion features of biped robot in the process of walk, theconnection method of toe and sole was put forward. Applying the flexible mechanismmethod, three kinds of flexible mechanism models were designed. The nonlinearanalysis method of SolidWorks Simulation software was used to calculate andoptimize the three kinds of flexible mechanisms, and their stress and displacementwere compared and analyzed. A kind of flexible hinge of toe which is suitable to"heeltouchdown, tiptoe liftoff"walking gait was designed, and it provided a possibility ofchanging the late walking way.4. From bionics standpoint, the whole structure design of bionic foot unit wasfinished. Based on the road condition, the toe structure and heel structure wereoptimized and make it have better adaptability to road, at the same time, the structureof absorbing impact on the heel was analyzed and optimized. Because of the goodtrait of shock absorber which absorbs impact, here the connection mechanism of shock absorber and spring plate was used. According to shock absorber parametersdetermined, the spring plate was analyzed by finite element method. In the end, thechoices of rubber material of foot bottom and torque sensor of six directions wereaccomplished.