{HEAD ~ The difference} between the square root of the distance and {TAIL ~ the moving velocity} is obtained by a substracter, and a feedforward signal is added to the difference 
between
{ HEAD ~ The difference } between the square root of the distance and { TAIL ~ the moving velocity } is obtained by a substracter , and a feedforward signal is added to the difference
HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH