Koji Nakashima

Robotics Research (United States), Yaskawa Electric (Japan)

Papers

Total Citations

H-Index

About

Koji Nakashima is a pioneering researcher in human-robot interaction, with a focused expertise on the psychological and physiological boundaries between humans and autonomous mobile robots. His foundational work investigates the concept of "personal distance"—the invisible spatial buffer people maintain when approached by a moving robot. In his landmark 1999 study, Nakashima demonstrated that a robot's approach speed directly influences how close a person will allow it to come, with faster speeds prompting larger desired distances. Using subjective reports and electrocardiogram measurements from young male participants, he established that these reactions are remarkably consistent within individuals. Extending this research, Nakashima examined how older adults (ages 53–83) perceive approaching robots, finding that while their personal distance also increases with robot speed, it shows no significant differences based on gender or posture. Though his citation counts (17 for his most-cited paper) reflect a niche but critical area, his work has direct, real-world impact: it informs the design and deployment of mobile robots now used for transport tasks in hospitals. Nakashima’s insights remain essential for creating robots that navigate human spaces safely and comfortably.