Abstract: A robot operating system according to the present disclosure includes: an information processor that evaluates a condition of a care-receiving object person on the basis of measurement information measured by a sensor included in a nursing care robot; and an action controller that causes the nursing care robot to gradually approach the object person on the basis of a result of evaluation by the information processor while temporarily stopping at a plurality of approaching positions having different distances to the object person, and causes the nursing care robot to execute a nursing care action including condition observation on the object person and communication with the object person.