Towards an understanding of dancers´ coupled body dynamics for waltz

In this paper, we study two dancers´ coupled body dynamics when dancing a waltz. A linear inverted pendulum (LIPM) model for biped locomotion is utilized as each dancer´s dynamic model, and a balance controller for each dynamic model is introduced. A pair of dancers are then modeled as two spring-damper-connected LIPMs with their respective controllers. Assuming a perfect rhythmic and synchronized motion, we analyze the stability of the physical interaction. Stable interaction with minimal interaction force is used as the criterion for optimal interaction, which is transformed into a quadratic programming problem and solved by gradient descent. Simulations and experiments show the proposed approach for analysis of the coupled dynamics is reasonable.