On The Passive Stable Walking Control Method For Three-Dimensional Bipedal Walking Robot

In recent years, the research of passive dynamic bipedal walking robot has graduallybecome the hot topic in humanoid robot development, which evolves from the simpletwo-dimensional passive slope walking to the3D actual dynamic gait. And various passivedynamic walking prototypes are developed. Considering the study of3D passive dynamicwalking, this paper focuses on the issues of the modeling and control of the3D passivebipedal robot, the design and control of the ADAMS prototype, which is supported by the863Program and National Science Fund Project. The contents are as follows.1) A new3D bipedal walking robot model with the laterally swinging upper body isdeveloped, considering the great significance the upper body provides to the lateral balanceduring the passive dynamic walking. Based on the sufficient analysis of the lateral andsagittal movement of the upper body, the continuous forward swing phase and the collisionswitching stage(knee collision and feet touching ground collision) during walking aremodeled respectively. And this paper builds the3D bipedal walking model based on thehybrid dynamic theory.2) The lateral control stability is the prerequisite for the continuous stable walking of the3D bipedal walking robot. The3D bipedal walking model with the laterally swinging upperbody can keep the lateral stability by the lateral swing of the upper body which is based onthe hybrid zero theory. It achieves the stable dynamic gait on the plane, verifying thefeasibility of the3D bipedal robot model.3) Design of the biped robot prototype depends heavily on the simulation techniques.Considering the prototype PADW-JLU II, two bipedal ADAMS prototypes that can be usedfor the control method study of the biped robot are designed: the biped prototype withlinkage upper body and the3D biped model. Besides, the ADAMS parameter identificationis adopted for the structural uncertainty of the ADAMS prototype, which is based on thegenetic algorithm and can reduce the structure difference between the theoretical model andthe actual prototype.4) The bipedal robot control algorithm based on ADAMS prototype can provide theprevious experiments and theoretical foundation for the actual walking control algorithmdevelopment. Through the analysis of the double-foot board institution of the ADAMSprototype, the lateral ankle torque compensation control method and the lateral and forwardperiod match control method are designed for the lateral control for the bipedal ADAMSprototype. Under the guidance of the adaptive torque compensation control strategy usingFSM, the lateral and forward period match control method can achieve the stable period gaitfor the3D bipedal model.Under stable initial gait condition, the ankle control strategy based on the lateral and forward period match control method can make the bipedal ADAMS prototype reach thestable humanoid gait, combined with the sagittal plane control strategy. It can providedirection for the design and control method debugging for the actual bipedal robot.In conclusion, this paper conducts a series of studies of the passive dynamic walkingcontrol theory and the prototype mechanism control for the3D biped robot, which haspositive implications for the biped robot research.