Gait Planning And Control For Biped Robot Based On DCM

Biped robots have human-like physical features and gait patterns.They can move flexibly through bipedal walking in the production and living environment of human society,without establishing a special workplace for them.The biped robot is considered to be one of the best forms of robots that can enter human society and provide services for humans.However,unlike other types of robots,biped robots have complex legs and feet structures,and it is difficult to build a dynamic model.Biped robots have many degrees of freedom,which makes gait planning difficult.They have large body size,high center of gravity,and small contact area with the ground,making them difficult to control in the process of walking.Therefore,biped robots have high energy consumption and susceptibility to interference during walking.In the past 50 years,biped robots have received widespread attention from academia and industry,and have achieved many achievements,but they are still far from realizing the goal of entering human life and serving people.Biped robots become one of the most challenging problems in robotics.In this thesis,the research on the dynamic model,trajectory planning and control method of the biped robot.The goal is to establish a biped robot walking pattern with high stability and low energy consumption and a control method with high robustness.The main contents are as follows:1.A simplified model is established.By analyzing the limitations and deficiencies of the traditional inverted pendulum model,a liner inverted pendulum model with finite-sized foot and angular momentum is proposed,and its dynamic equation is derived by Lagrangian method to obtain the dynamic model of the biped robot.The stability criterion of the divergent component of motion is introduced.Based on this criterion,the gait pattern of the biped robot is established,and the control system of the biped robot is designed.2.A stable and efficient walking pattern is planned.Based on the above model,the trajectory of the swinging leg is improved so that the heel lands first and the toes land behind.At the same time,the "landing" sub-phase is added in the double-support phase to improve the stability margin.The trajectory of divergent component of motion is planned based on capturability theory,and the gait is optimized with the goal of minimizing energy consumption using particle swarm optimization.3.A walking control system is designed.We build a predictive model for model predictive control and use model predictive control to track the trajectory of the desired divergent component of motion,then,obtain the controller constraints based on the zero moment point criterion and physical constraints.The extended Kalman filter is used to estimate the weights while compensating for external disturbances.In addition,the Co M-ZMP inner loop controller is designed to stabilize the zero moment point,then give the solution of inverse kinematics.Through the simulation experiments,it is proved that the biped robots have a larger stability margin under the above-mentioned gait,and have the ability to walk smoothly under the condition of disturbance under the above-mentioned control method.