Versatile Collaborative Robot Applications Through Safety-Rated Modification Limits

A robot is a flexible tool and handling device. However, by eliminating safety fences in robotic applications, flexibility is limited as regulations on personal safety must be followed. Any modification on the system or application will require a new risk assessment before the system can be put back into operation. This circumstance costs time and money and stands in contradiction to the nature of a robot as a versatile and adaptable device. By introducing safety-rated modification dimensions and determining admissible variations indicating the limits up to which the system or application can be changed in compliance with safety regulations, a potential solution to overcome this restriction is presented. A model-based strategy for estimating and validating the aforementioned modification limits is proposed, up to which changes on the system can be made without conducting a new risk assessment. The proposed approach gives rise to a novel safety concept for collaborative robotic applications, which ensures flexibility while taking into account safety standards.