An inverted pendulum with a springy control as a model of human standing

Frank Borg

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An inverted pendulum with a springy control as a model of human standing

Frank Borg

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Abstract

The normal and the inverted pendulum continue to be one of the main physical models and metaphors in science. The inverted pendulum is also a classic study case in control theory. In this paper we consider a special demonstration version of the inverted pendulum which is controlled via a spring. If the spring constant is below a critical level the springy control will be unstable and the pendulum will be kept from falling only by exercising a dynamically varying control. This situation resembles the case of human bipedal quiet standing with the Achilles tendon serving as the spring. The paper is written with physics students in mind.

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Frank Borg. 2005-12-14. An inverted pendulum with a springy control as a model of human standing. https://arxiv.org/abs/physics/0512122

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