Control Strategies of Human Interactive Robot Under Uncertain Environments

Abstract

Actually, the research on human interactive robot (HIR) has been a topic of both science fiction and academic speculation for a long time. The origin of HIR as a discrete issue was stated by 20th century author Isaac Asimov in 1941, in his novel “I, Robot”. He stated the Three Laws of Robotics1 as, “ a. A robot may not injure a human being or, through inaction, allow a human being to come to harm. b. A robot must obey any orders given to it by human beings, except where such orders would conflict with the First Law. c. A robot must protect its own existence as long as such protection does not conflict with the First or Second Law. ” The three laws of robotics determine the idea of safe interaction which constitutes the basic rules of HIR. With the advances of artificial intelligence (AI), the HIR could eventually have more proactive behaviours, planning their motion in complex unknown environments. Nowadays, HIR are artificial agents with capacities of perception and action in the human’s environment. Their use has been tended to be found in the most technologically advanced societies in critical domains as search and rescue, military battle, law enforcement, entertainment, hospital care, etc. These domains of applications imply a closer interaction with human. The concept of closeness is to be taken in its full meaning, HIR and humans not only share the workspace but also share goals in terms of task achievement. The HIR has to adapt itself to human’s way of expressing desires and fulfill its task. Taking lifting up human in elder care for example, the human interactive robot RI-MAN, designed by the RIKEN Bio-Mimetic Control Research Center, communicates with human by listening and speaking, which makes it understand the human will (Onish, Luo et al. 2007). To fulfil the task, it also estimates the attitude of human body in real-time by tactile sense (Mukai, Onishi et al. 2008). This example contains two aspects of HIR, one is to understand the human mind and the other is to accomplish the manipulation. The former is based on AI techniques, like language comprehension, and the latter is relied on force control. On the other hand, human’s environments are much more complex. Thus, the HIR needs perceiving and understanding capacities to build dynamic models of its surroundings. It