Research On Gait Planning Of Biped Walking Robot

The research field of biped robot is a typical interdisciplinary field.The human-like structure makes it more flexible to complete the complex movements that are difficult for other types of robots.Therefore,it has a wide application prospects in various fields,and it has also set off a research upsurge of biped robots.The difficulty of the current biped robot research is the stability problem during its movement,especially in complex environments such as obstacle avoidance,up and down stairs,it is more important to maintain stability.Gait planning is an important part of studying its stability,and it is also a hot spot in current research.This paper conducts an in-depth study on gait planning and makes some improvements.The main research contents are as follows:Firstly,the research background and significance of the project are briefly summarized,the development history and research status of biped robots at home and abroad are introduced,the existing gait planning methods are summarized and classified,and their advantages and disadvantages are analyzed;Secondly,the seven-link optimization model with the foot link of the robot is studied,which reduces the model error.The forward and inverse kinematics models of the sagittal plane and the front plane of the biped robot are established by decoupling method,and the formulas of each joint and joint angle are derived.The zero moment point criterion is studied emphatically,and the walking stability condition is deduced,which provides the model basis and theoretical basis for gait planning;Thirdly,the gait planning method introducing hip joint swing is discussed.By setting reasonable constraints,the position and posture of the robot at each critical moment are calculated,and the motion curves of each joint and joint angle are solved by cubic spline interpolation.By comparing the two walking modes of hip joint swing and traditional hip joint non-swing,it is proved that this method can effectively improve the stability of the robot;Finally,the gait planning method based on non-time reference variables is studied.The x-direction trajectory of the hip joint center is used as a reference variable,and the smooth trajectory of non-time variables of each joint and joint angle is solved by trigonometric function fitting method.It is proved that this method does not need to consider time-related problems such as the stability of zero moment point and dynamics,but only studies the external walking environment of the robot.It has obvious advantages for planning gait in complex environments such as running,going up and down stairs and avoiding obstacles.