Photo: Junko Kimura/Getty Images

These mechanical debutantes made their entrance last June at the prototype robot exhibition of the 2005 World Exposition, in Nagoya, Japan. The Partner Ballroom Dance Robots are the joint work of the Japanese robotics and machinery maker Nomura Unison Co., in Chino City, and the laboratory of Kazuhiro Kosuge at Tohoku University, in Sendai. Much of Kosuge's research involves getting robots to understand human intentions and to predict their actions. Just as a human dancer would, the robot reads its partner's next move by noticing the force and torque against its body. It looks up in its memory what that signal is likely to mean in the context of the dance it is performing and sends the correct motion commands to three motorized wheels hidden under its plastic dress.