Estimating Contacting Points by Force Sensing in Cooperative Transpotation

This paper deals a strategy to estimating contacting positions between transported object and multiple mobile robots with force sensors. One of the most important problems in cooperative transportation by multiple mobile robots is to realize relative positions among contacting points around an object. It is demanded to recognize current position of a robot itself in world coordinates or to avoid some obstacles; but a physical constraint through an object between cooperating robots is dominant in cooperative transportation. For recognizing a motion error of mobile robots, this system estimates positions of robots by a physical constraint as mentioned above. A physical constraint is obtained by force sensor value from each robot. This constraint and a geometrical shape of an object enable the system to estimate an arrangement of contacting points around the transported object. Our numerical simulation and expetiment have verified that contacting positions between robots and an object can be estimated without an external means to estimate contacting positions; such as vision system or anything else.