Motion Analysis and Experiment of Passive Walking Robot Quartet II.

Robot, which has no actuators and walks down a slight slope, is called ‘passive walking robot’. It is well known that the passive walking robot is important and interesting target. In the past papers, , a stable steady periodic motion and a chaotic behavior of passive walking robot were analyzed by numerical simulations. To justify the numerical analysis, we have to show the occurrence through experiment. However, we have not ever seen experimental analysis concerned with those behaviors.Therefore, in this research, we constructed a passive walking robot named QUARTET II and tried to show the occurrence of the behaviors. In this paper, at first, we explain QUARTET II. Then, we show that, in passive walking, a few interesting behaviors mentioned above are observed via some numerical simulations. And finally, we show that those behaviors occur in walking experiments. Especially, it is noticed that we could observe a bifurcation in passive walking experiments. This is the main contribution of this paper. This experimental result is very important for biped robotics.