Towards a safety index for assessing head injury potential in service robotics

There are many standards worldwide dealing with safety issues in robots and adequate protections for their industrial use. Two main safeguard actions are considered to avoid mechanical risks, namely physical or non-physical protections and design guidelines for robots and their components. Nevertheless, there is a lack of specific standards for service robots. Safety in these robots needs a new point of view. It requires a strategy to be changed from pre-contact to post-contact safety, since it is not possible to avoid human-robot interaction. On the other hand, in automotive industry crash test results are used for assessing car safety by means of safety indices. In this paper, quantitative head injury indices for automobiles are analysed and a new safety index for robots NIR is derived. The similitude between NIR and indices used in automotive industry lets the new index to take advantage of previous results and knowledge available in automotive field. Results with NIR are compared with those given by experimental tests with robots. The effects of main parameters on the new index are analysed and results are compared with other safety criteria in order to clarify differences and benefits.