Prototype Development And Walking Experiment Of GTX-? Biped Robot

Biped robot can complete the task instead of human in complex and harsh environments such as post-disaster reconstruction,seabed and space.Therefore,the biped robot is entrusted with the good wishes of mankind in the industrial and service industries.With the support of the National Natural Science Foundation of China,'Multi-source random uncertainty modeling,intelligent control and dynamic simulation experiment on biped robot(No.11372270)','Gait transition,multiobjective optimization and robust control on random uncertainty of 3-D biped robot(No.11772292)',and 'Dynamic modeling and whole-body control of biped robot with rigid-flexible-soft structure(No.91748126)' and so on,this dissertation carries out the development and walking experimental research of GTX-III biped robot prototype.The main research works are as follows:(1)The design of a 14-DOF GTX-III biped robot prototype containing waist pitch and roll freedom,which laid the foundation for subsequent lumbar adjustment research.Firstly,the mechanical structure design of GTX-III biped robot prototype is completed in SolidWorks.Then,the virtual prototype model is established in ADAMS,and the simulation optimization analysis is carried out for the leg quality and the concentrated trunk quality.Finally,design parameters of the physical prototype is optimized according to the simulation results.Then,making the physical prototype.(2)Design a control system designed to shorten data transmission time and improve control efficiency to achieve stable walking of the biped robot.Firstly,the sensor for feedback control,the chip of the lower computer and the upper computer are selected;Then,design the hardware system,by designing a dedicated level conversion circuit,the device with large data is directly connected with the upper computer,cutting the data retention time in the lower computer,improving the control efficiency and shortening the data transmission time.Finally,according to the custom upper/lower computer agreement,the software system of the upper/lower computer is prepared.(3)For 3D-LIPM-based gait planning,the ankle joint trajectory is optimized,and the bipedal support period is introduced.A joint flexibility improvement method and a gait switching method are proposed respectively.Firstly,based on biped robot modeling and stability analysis,the kinematics model,3D-LIPM dynamic model and stability analysis are derived.Secondly,in the gait planning process of biped robot,the centroid and ZMP trajectory are planned based on 3D-LIPM dynamic model,and adds the vertical landing stage in the ankle trajectory planning process.Further,by setting constraints,the smooth transition of the bipedal support phase centroid trajectory is added based on the sixth-order polynomial interpolation.Then,a method for improving the joint flexibility based on the lumbar adjustment is proposed to improve the flexibility error of the hip joint lateral motion of the biped robot.Finally,a two-step gait transition method is proposed to transition to the target step size,and the gait transition experiment is completed on GTX-? biped robot prototype.The experimental results show the effectiveness of the gait planning method and gait transition method adopted in this dissertation.(4)Through analysis of the sensor layout of GTX-? biped robot prototype and its function,the feedback parameters of feedback control is determined.By analyzing the relationship between the feedback parameters and the real-time attitude of the biped robot,a feedback controller based on the lumbar adjustment is designed.This includes analysis of the real-time attitude of the robot and the design of the incremental PID controller.Finally,by applying the feedback controller on the GTX-? biped robot prototype,it is verified that the biped robot feedback controller based on the waist adjustment can help the robot resist certain external interference.