Risk Assessment and Functional Safety Analysis to Design Safety Function of a Human-Cooperative Robot

Human-cooperative robots (HCRs) are expected to benefit various industries, and many studies related to physical human-robot interactions have been conducted (Moore et al., 2003; Kim et al., 2005; Tsuji et & Tanaka, 2005); some HCRs have been gradually introduced in manufacturing and welfare fields. For instance, power-assist systems in manufacturing assist workers in carrying heavy modular parts to the target site (Konosu & Yamada, 2003; Santos et al., 2010). In the welfare field, power-assisted meal-carrying carts enable caregivers to move numerous dishes at once (Fujiwara et al., 2002), and electro-hybrid wheelchairs make it easier for caregivers to move a person with weakened leg muscles (Seki et al., 2006).