Research On Analysis Strategy For Human Walking Stability Recovery Under Large Disturbance

The research for biped robots has been a hot spot in the research field of robot at home and abroad.Compared with other types of robots,biped robots have advantages of upright walking,high degree of freedom and flexible action.However,due to the limitations of its structural design,the biped robots have poor gait stability and high sensitivity to the external environment.Under the action of large external disturbance,the stability of biped robot system will deteriorate rapidly and the biped robots will fall easily.Therefore,how to maintain its good,stable and rapid recovery ability under the influence of large external disturbance is a issue that needs to be solved urgently in the research field of biped robots.For the problem presented,referencing under large disturbance of human gait adjustment method,through accurate characterization of human motion characteristics in the process of human disturbance recovery,this paper effectively analyzes the stability of the disturbance of human body after recovery control strategy,establishes the analytic simulation platform of human walking recovery process under large disturbances,provides advanced theoretical basis for the control strategy of biped robots under large disturbance.The main research work of this paper is as follows:Firstly,for the fast and stable characterization of biped robots under large disturbance,the stability perception prediction model of human body disturbed by large disturbance is established by taking human body large disturbance walking as the research object.In view of the complex physiological structure and sensitive perception and regulation system of human body,the idealized assumption is made for each component of human body based on the rapid characterization of the stability perception of human body under large disturbance,and the 3D-LIP point foot model at the center of mass of human body is established.On this basis,the capture point analysis and capture point dynamics analysis under any state are realized by introducing the motion capture point theory,which lays a model foundation for the subsequent stability perception analysis of the biped system model after being disturbed.Secondly,in view of the problem of stabilization capture and recovery control ofhuman body under large disturbance,the decoupling and isotropic processing of human body's three-dimensional motion is realized by using 3D-LIP point foot model,and the stabilization capture and prediction under any state of the model is realized by combining capture theory.On the basis of restricting the step time and step distance of the model,a dynamic foot positioning controller based on motion capture is proposed,the controller realizes the disturbance recovery control of 3D-LIP point foot model under different external disturbance by predicting the gait of the model and controlling the landing time and position of the swing leg.Thirdly,aiming at the control deviation problem of the 3D-LIP point foot model proposed in this paper,a double pendulum leg model which is more similar to human physiological structure is proposed.In order to eliminate the control deviation between the3D-LIP point foot model and the double pendulum leg model,a discrete LQR controller was introduced.Through the research on the disturbance recovery control of the double pendulum leg model under different disturbances,multiple disturbance control recovery of the double pendulum leg model based on the stable prediction is achieved.Finally,based on the multiple disturbance control recovery process of the double pendulum leg model under the stable prediction,the motion control recovery data under the large disturbance of the human body is obtained by human motion capture device,then the human body capture experimental data and the simulation data of the double pendulum leg model are compared and analyzed.The experimental results show that there is a high consistency between the experimental data of human body and the simulation data of the double pendulum leg model in the process of disturbance recovery,which further verifies the feasibility of the simplified human body model in this paper to describe the disturbance recovery process of human body and the validity of the control strategy analysis.