abstract
- © 2022 IEEE.A pendulum with two segments can be used to study the behavior of a human-like system which considers motion at the ankles and hips. Stability of such a system can be achieved by means of joints' torques provided by the muscles, but this approach may be energetically taxing. Other methods have been suggested to act concurrently and take advantage of the passive dynamics of the system. One such approach is described as the Kapitza's pendulum where upright stabilization of a pendulum may be achieved by the application of a vertical periodical oscillation at its base. This work studies the effect of the Kapitza's oscillation on a two-segment inverted pendulum with anthropomorphic characteristics. It shows that the Kapitza's effect is sufficient to stabilize the system in an upright posture. The system was analyzed numerically by solving its Dynamic Model under different conditions. While the results presented mirror those previously reported, this work finds a larger region of stability when compared to the available literature. This is likely due to the effect of the top heavy-pendulum and its inertial properties. Additionally, under this study the effect of the joint visco-elastic parameters is made evident: while they generally tend to help stabilize the system, they sometimes hinder stability, specifically under low frequency - high amplitude oscillations. Future studies should include a more accurate model of the time-varying characteristics of the joints' visco-elastic parameters and human range of motion.