Walking control of the humanoid UT-Theta

This paper discusses walking control of Theta, an innovative humanoid walking robot equipped with a double spherical hip joint and a knee joint switchable between active and passive operation mode, which has been been developed at the University of Tokyo. The walking generator and controller is presented, including some implementation aspects. It is based on the inverted pendulum approach with the innovative feature of fully using the double support phase for the walking generation and control. A method for estimating the body orientation without using gyroscopes and accelerometers is also proposed, together with the main ideas regarding the control of the active/passive knee. Relevance to practical application is proved by hardware experiments.