Systematic derivation of simplified dynamics for humanoid robots

Simplified models such as the inverted pendulum model are often used in humanoid robot control because the full dynamics model of humanoid robots is too complex to design a controller. These models are usually derived from simple mechanical systems that represent the essential properties of the robot dynamics. This method for deriving simplified models is a manual process that heavily relies on the controller developer´s intuition. Moreover, mapping the state and input between the original and simplified models requires model-specific code. This paper describes a general method for systematically obtaining simplified models of humanoid robots. We demonstrate an application of derived models to humanoid robot balance control using linear quadratic regulators.