Human Balance Dynamics Analysis Considering the Influence of Foot Pressure Feedback
With the increasing prevalence of social aging,the prevention of falls in the elderly has become an important research topic. In this context,it is of great significance to explore the human balance mechanism based on time delay system dynamics for the purpose of improving the balance ability of the elderly and providing theoretical support for the development of fall prevention aid equipment. In this paper,with the influence of foot pressure feedback into consideration,a single-degree-of-freedom invert-ed pendulum with time-delay feedback control model is established. For the case of the foot pressure feedback delay,position feedback delay and velocity feedback delay with a ratio of 1∶2∶2,the stable region diagrams of position feedback gain versus velocity feedback gain,time delay versus foot torsional stiffness and time delay versus foot feedback gain are discussed. Considering the influence of geometric nonlinearity and control torque saturation,Hopf bifurcation analysis is carried out with respect to time delay by the method of multiple scales. The results show that with the increase of the foot torsional stiffness or the foot feedback gain,the critical time delay decreases and supercritical Hopf bifurcations appear.