Research On Structure Design And Motion Control Of Parallel Legged Bipedal Robot

Foot robots have good terrain adaptability,and can replace human beings in the nuclear accident area,virus infection area and other hazardous human health scenes to carry out rescue,transport anti-epidemic materials and other tasks.Aiming at the problems of low load,poor motion performance and unstructured road surface adaptability of the traditional bipedal bionic robot with parallel legs,a kind of biped robot with parallel legs is studied in detail.In this paper,the robot is taken as the research object,and its configuration analysis and design,kinematics modeling,control system design and experiment and other aspects are studied.The specific contents are as follows:The configuration analysis of a biped robot with parallel legs is studied.A complete 6-DOF parallel mechanism is used as its leg,and its moving platform is designed as a rigid "arch" in the shape of an arch.The two arches are distributed up and down and have space for staggered movement to form a nested configuration,thus completing the configuration design of the parallel legged biped robot.On this basis,the degree of freedom,workspace and mechanism performance of the parallel leg are analyzed,which shows the superiority of the robot configuration.The kinematics model of a biped robot with parallel legs is established.Taking the leg mechanism as the research object,the coordinate system was established,and then the position model and velocity model of the parallel leg were obtained.The validity of the kinematics model was verified by Simulink simulation.In order to reduce the ground impact when the feet of the swinging legs touch the ground,the trajectory of the feet is planned and a reasonable conventional gait is designed to meet the requirements of the robot walking.Adams was used to simulate the gait of the robot,and the simulation results proved that the robot had good movement ability.In order to make the robot have good motion control ability,the joint space PID control strategy of the leg mechanism was established.The effectiveness of the control strategy was verified by simulation with the planned foot trajectory as the input signal of the system.An improved return to zero dynamic control method in mission space is proposed,and the feasibility of the control strategy is verified by theoretical analysis and simulation experiments.Through the comparative analysis of the simulation results of the two control strategies,the control strategy based on joint space is selected to apply to the actual control system.After the full theoretical research and simulation experiments,the design and experimental research of the robot prototype are carried out.The control experiment of the single leg of the robot was carried out,and the data of the length variation of the electric cylinder were obtained.Experimental research was carried out,including straight walking and rotating gait experiments,load-bearing and obstacle-crossing experiments.The experimental results proved that the parallel legged biped robot not only has good gait movement ability,but also has high load and obstacle-crossing ability.The research results of this paper provide some references for the research on the configuration design and motion control of parallel mechanism based walking robot.