Design And The Stability Study Of The Nonlinear Support Of The Bipedal Mobile Robot

The bipedal mobile robot is an exoskeleton suit that can be wore on human beings and it keeps the same gait with the user at any time. It carries the load for human like the real skeletons which can remarkably reduce the tiredness and pain of the legs during long distance, heavy loaded walking under some specific circumstances. What’s more, the exoskeleton suit can also be applied as an assistant equipment to the disabled who survived from a traffic accident or earthquake. The potential applications mentioned above indicate a bright future to the research of the exoskeleton suit. The mobile robot in this paper is the bipedal mobile robot as the exoskeleton.The support structure of the mobile robot is the only point that contacts with the ground, so it is extremely critical to study the support of the mobile robot based on human foot.Firstly, the foot skeletons, muscles, ligaments and arch were analyzed in this paper according to the anatomy and biomechanics of the human motion. The biomechanical characteristics of the arch and the characteristics of human gaits were also studied.The experiments to study the biomechanics of the human foot were conducted based on the analytical results of the characteristics of the human foot and anthropometry. A foot motion capture system and a foot force measurement system were constructed to capture the angle variation of the foot joint and the change of the arch. According to the experiment data acquired from the measurement system, a mechanical model was successfully established, future on, combined the kinematicsresult of foot joint with foot forces, the dynamic data of the human foot were acquired.A bionic nonlinear support structure was designed based on the characteristics of the human foot and the experiments results of the biomechanics. Modeling and analyzing of the support structure was conducted. After finishing material selection and size design, verification was done before assembling and machining.At last, the motion stability was analyzed based on the designed nonlinear support.To collect the angle variation information of the hip joint, knee-joint and ankle joint and the swing distance of the center of gravity during walking, we used the designed nonlinear support and the linear support to replace the human foot. Compare the experiment results with the data when human walk normally, we found the data collected from the experiment which uses the nonlinear support is more similar to the normal human walking results. It indicates the nonlinear support designed in this paper has quite excellent motion stability.