Research On Gait Planning And Control Of Biped Robot With Heterogeneous Legs

The Biped Robot with Heterogeneous Legs(BRHL)is used as an artificial prosthetic experimental platform.The artificial legs mimic the healthy leg walking of disabled people,and need to have stable,anthropomorphic gait and self-balancing ability.Therefore,it is of great significance to study the gait planning and control of artificial legs.This paper focuses on the following aspects of artificial leg gait planning and control:(1)The original artificial leg structure was improved,and a six-bar knee joint driven by pneumatic artificial muscle was designed,which made the artificial leg more light and bionic;the kinematics of the artificial leg was modeled as gait.The solution to the joint angle during planning lays the foundation.(2)Artificial leg offline gait planning.A gravity compensation inverted pendulum model is established in the single leg support phase,and a virtual inverted pendulum model is established in the support phase of the legs.A virtual-real inverted pendulum system is proposed to obtain the BRHL centroid motion trajectory.According to the BRHL centroid trajectory and kinematics model The joint angle time series was obtained and phase plane analysis was carried out.The ADAMS simulation was carried out.The energy optimization method was used to optimize the BRHL centroid trajectory.(3)Artificial leg upright balance control.The simplified model is used to analyze the stable region of each balancing strategy.For the ankle joint balancing strategy,the inverted pendulum dynamics model is established,and the virtual impedance controller is designed.According to different performance indicators,the linear quadratic controller is used to optimize the impedance parameters.And analyze the influence of each parameter on the control effect;under the condition of no external force and transient external force interference,the ankle joint control strategy is verified by MATLAB/ADAMS joint simulation.(4)Artificial leg online gait planning.Based on the pre-view control method,the BRHL is planned online,and the car-table model is used to model the dynamics of the two-legged heterogeneous robot.The controller is designed.The BRHL centroid trajectory is generated by different reference ZMP trajectories,and the ZMP tracking error is analyzed.,centroid velocity and acceleration,determine the best ZMP trajectory;analyze the pre-view controller control parameters,find the influence of each parameter on online gait planning;generate online gait mode for BRHL.