Research On Gait Planning And Walking Stability Control For Humanoid Robot

Humanoid robots are similar in appearance to human beings.It compared with other robot had using two foots walking on the road,So this character made it more flexible and little limited by the environment.Therefore,the research of humanoid robot in recent years has attracted wide attention from scholars.In order to improve the walking stability of humanoid robot.The study of gait planning and stability is the key technical problem of humanoid robot.There,The gait planning of humanoid robot is the basis of walking control.Walking control is a guarantee of gait planning.Therefore,this paper takes humanoid robot as the research object.The matlab is used as the simulation experiment platform,so the gait planning technology and walking stability control method of humanoid robot are systematically studied.The content of this paper is divided into the following aspects:1.Nao robot is used as the object,Firstly,the corresponding coordinate system is established according to the link model.The D-H rule and Lagrange method are used to deduce it.An equation describing the kinematics and dynamics of equal degrees of freedom is established.At the same time,the inverse kinematics equation is established by the analytic method.The definition of ZMP is explained according to the dynamic equation.so the stability condition of humanoid robot in walking is studied,the stability criterion of ZMP is obtained.2.In reference to the traditional gait planning method.According to the humanoid robot lower body ankle,patellar,knee joint in humanoid robot start,the foot to reach the maximum height,the foot landing position.Using spline interpolation algorithms to plan the humanoid robot's Ankle,patellar joint,knee joint and other humanoid robot lower body major joint trajectories in the radial plane and the lateral plane and draw the stick figure of the humanoid robot straight walking.3.Using the distance between ZMP and the center of stable region at each moment of both single and double support phase as parameter,and then optimizing the distance parameters using particle swarm optimization algorithm,in order to keep the ZMP of gait as close as possible to the center of stable region.4.The stability control of the robot was studied after the gait optimization,the control object is a humanoid robot's ankle and shoulder joint.The ankle joint which has the greatest influence on the ZMP position of the robot adopts the control method to track its motion trajectory.Firstly,the fuzzy controller is designed according to the walking characteristics of the robot,and then the fuzzy toolbox of matlab is used for reasoning calculation.The effectiveness of the fuzzy controller is verified by the final simulation results.The method of planning arms swing is adopted for shoulder joint control.Firstly,the function of ZMP position and offset moment is used to calculate the magnitude of offset moment.Then the swing moment of the arm with the opposite swing moment is calculated by the parameterized trajectory of the arm swing.So objective function is constructed with the difference between the moment and the offset moment.By finding the minimum value of the objective function,the two arms with the minimum swing moment can be obtained.last,the anti-falling and anti-interference ability of the robot can be enhanced by swinging the walking control method with the inner loop's fuzzy controller and the outer aim swing.