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