Research On Gait Planning And Stability Of Biped Robot On Stairs

Compared with other mobile robots,biped robot is more capable of adapting to environment.One of the most important performances to evaluate biped robot's walking ability is its adaptability in various complex environments including going upstairs and downstairs,slope and turning.Stair is a common walking environment in human daily life,so it is significant to study the stability and related characteristics of biped robot climbing stairs.The gait planning and study on stability of biped robot climbing stairs are the foundation and key to solve biped robots walking in complex environment.The paper took modularized humanoid robot developed by Shanghai PartnerX Robotics Co.Ltd as study object and studied the gait planning and stability of biped robot.The following research works have been done through theoretical analysis,simulation and experiment.Firstly,based on the inherent parameters of modular humanoid robot,the author made feet,thighs,crus and torso as the equivalent of a seven link model and used D-H representation method to establish forward kinematics model and built inverse kinematics model through geometric algebra,and then,the author gave the principles of stability criterion and conditions for stability of biped robot climbing stairs.Secondly,according to the characteristics of change of centroid and joint angle of biped robot when it climbed stairs,biped robot was simplified as elongated inverted pendulum model,and then,the author made gait planning for biped robot when moving forward,lateral,starting and stopping along stairs.Based on the theories of forward and inverse kinematics model,the author worked out the motion trajectories of each joint of biped robot's crura,and also designed stability evaluation function.Next,by using the numerical software called MATLAB/Simulink and ADAMS,a dynamic simulation software,the author built virtual prototype simulation system of modular humanoid robot climbing stairs,and realized joint simulation,and then got the change of the centroid and torque change of each joint angle when biped robot climbed stairs to verify the reasonableness of gait planning,and analyzed the stability and kinematics characteristics of climbing stairs,which provided a reference for designing and optimizing structure parameters of biped robot and studying the walking motion of biped robot in other complicated environments.Finally,through building experimental platform of the modular humanoid robot,the author used cable film pressure sensor collection system to collect the change of foot pressure on the stairs,and obtained the data of centroid change of biped robot climbing stairs after analyzing.By analyzing the stability of biped robot climbing stairs and comparing with simulation results,the author verified the effectiveness of gait planning and the control of stability.