wherein the actual force converter sets the external force capable of actually existing in {HEAD ~ a direction} of a normal vector of a link structure shape at a part of contact detected by the plurality of {TAIL ~ contact sensors} 
wherein the actual force converter sets the external force capable of actually existing in { HEAD ~ a direction } of a normal vector of a link structure shape at a part of contact detected by the plurality of { TAIL ~ contact sensors }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL