Risk Evaluation of Human-Care Robots

Human-care robots must be realized to nurse aged and disabled persons. These robots will need to work around elderly people and give them touches; therefore conventional safety strategies for industrial robots can not be applied to human-care robots. It is now necessary to make a new study of safety in the space where a human and a machine will exist together. In this chapter, I carry out a Case Study of assessing several human-care robots according to ISO/TR 12100-1:1992 and ISO 14121:1999. Next, I propose a risk evaluation method of human-care robots and define evaluation measures which describe the degree of safety. Next, I apply my method to evaluate several safety design and control strategies, and then I prove the viability of my risk evaluation method. These proposed methods enable us to optimally distribute cost among several safety strategies, and to derive suitable approaching motion of a multi-link manipulator to a human. The validity and effectiveness of these methods are demonstrated by numerical analysis. As a result, the design and control to increase safety are successfully obtained.