The Research On Biped Robot Gait Planning And Compliance Strategy For Touching The Ground

Due to its discontinuous contact with the ground,bipedal robots have a strong adaptability to uneven ground environment and high flexibility,especially suitable for post-disaster rescue,jungle exploration and other complex environment under the road movement,which is a hot spot in the current robot industry.However,because the bipedal robot system model is complex and is easily affected by the interaction impact between the feet and the ground during walking,the stability of gait,especially the flexibility after the feet touch the ground,has always been a representative problem in the bipedal robot field.Combined with the current research and development in this field,this paper mainly aims at the gait planning and foot touching ground compliance strategy of bipedal robots,and conducts the following research:(1)Overall model establishment and kinematics analysis of biped robot.Based on the analysis of bionic human lower limb motion mechanism,the degree of freedom and geometric size of the lower limb of bipedal robot were designed and the 3d model was built.Set up the hydraulic drive system and calculate the relationship between the joint Angle and the hydraulic cylinder.The forward and inverse kinematics model of the leg of bipedal robot was established to complete the calculation of joint Angle and foot end position,and the kinematics model was decoupled according to the structural characteristics of the leg.(2)Gait planning of bipedal robot and simulation analysis of virtual prototype.With reference to human walking gait,the trajectory planning of bipedal robot walking gait is carried out in the initial stage and periodic stage by combining the inverted pendulum model and polynomial interpolation method.The trajectory of each joint of left and right leg is calculated according to the inverse kinematics of leg.Based on ADAMS virtual prototype platform,the gait walking simulation of bipedal robot was carried out,and parameters such as trajectory of each joint of the legs,trajectory of the center of mass and contact force of the foot touching the ground were obtained.The simulation results verified the feasibility of bipedal robot mechanism design and gait planning method.(3)Foot end touching ground compliance strategy model building and controller performance simulation analysis.Based on the dynamic model of leg and foot touching the ground,the robust sliding mode impedance controller was designed and the stability of the control system was verified.The performance of the designed sliding mode impedance controller is compared by simulation,and a joint simulation model of foot touching ground is established to verify the applicability of the sliding mode impedance touching ground compliance strategy.