Design And Study Of The Gait Planning And Stability Control Of Biped Walking Robot On Focus

The biped walking robot has much better adaptation to environment in human living-space than wheel type, crawl type and pedrail type mobile robots. Researchers at home and abroad have been undertaken extensive research on the stability of biped walking robot.Three problems have been focused on in this paper: establishment of kinematics and dynamics models for the lower limbs of robot; gait planning and simulation of robot; design and simulation of robot fuzzy control system. The main tasks are as follows:Firstly,the degrees of freedom configuration and structure of the robot were designed; the direct-inverse kinematics models for robot based on homogeneous coordinates transformation theory was made in pole coordinates, the base for the following gait planning was provided. Dynamics models with the Lgrange dynamic equations for the single-foot support and the double-foot support were established, which can be used in control.Secondly,the basic principle and method of the robot gait planning was analyzed,gait planning on robot static walk was based on barycenter imitation.Traditional two-step gait planning method was improved to make the robot gait much more smart and stable.The dynamic equations of the three walk gaits were established separately, the robot pose and track were transformed into joints rotating curves ,computer simulation was made on MATLAB-based gait results, the planning validity was indicated. The robot ZMP(Zero Moment Point) stability criterion was presented, using which the gait error analysis planned was carried out, the joint moving curves were modified, the coupling of the forward displacement and lateral displacement at the same time was eliminated, the robot motion would be much more fluent on the condition of stability.Lastly,the correlative theory about fuzzy control was introduced, the ZMP point was analyzed, the robot would be much more stable when analyzed ZMP point was prone to the center of support plane, however, the ZMP point position was adjusted by robot ankle joints. Take the left ankle joint as example: the robot stable and fuzzy control was designed on fuzzy theory, which was imitated in MATLAB. It is indicated in the simulation results: the ZMP point positon can be adjusted by the relative rotation of the robot joints, the static robot walk was realized, at the meantime , the stability of robot was guaranteed.