In other words, {HEAD ~ the position} and velocity of {TAIL ~ the center} of gravity at the start point may be the position and velocity of the center of gravity at the current time as measured by sensors 
of
In other words , { HEAD ~ the position } and velocity of { TAIL ~ the center } of gravity at the start point may be the position and velocity of the center of gravity at the current time as measured by sensors
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH