Structural Design And Trajectory Tracking Of A Six DOF Biped Robot

The research of biped robots promotes the progress of the industrial robots and the development of related disciplines and raises the level of the human life.Mechanical structure,kinematics and dynamics model,gait programming and control system of trajectory tracking of a six DOF biped robot were studied in this paper.Firstly,the material and the drive of the robot were selected.Every degree of freedom was assigned over the hip,knee and ankle of the robot.The design of mechanism was divided into three parts: hip platform mechanism,foot platform mechanism and four connecting parts.Every part was designed on Antocad and Pro-E.And the robot was assembled on Pro-E.Secondly,according to the characteristics of biped robots structure,a fivelink model was established to reflect the dynamic characteristics.Mathematical model of the robot was builded by generalized coordinate method.And a function of time for each robot joint angle and a dynamic model which is easy to tracking control of the robot were obtained.It is the foundation for the research of the back.Thirdly,based on the ZMP stability theory,the ZMP calculation formulas were used as a judgment basis for gait programming of the robot.During walking,the swinging foot just to leave and to contact the ground and the highest point of the leg were selected to be three important gesture points.The gait trajectory of the hip and ankle of the robot were designed by three-points programming method and geometric and acceleration constraints.Through inverse kinematics equation of the robot,we obtained every trajectory function of the robot joint angle and ZMP trajectory of the robot which is used to judge the stability of the robot during walking.Matlab simulation results illustrated the rationality of the programming method and provided curves expected for later study.Finally,The appropriate sensor of the robot was selected and it made the robot detect the black line.in the process of walking.Based on the previous study,for the dynamic equation of the five-link model of the robot system with uncertain disturbances,A global and fast terminal sliding tracking controller was designed.Matlab simulation results verified the effectiveness of the control method and realized function of trajectory tracking,and avoided chattering that the traditional sliding tracking control systems often occur.