a control means including a CPU for controlling {HEAD ~ said wheel driving means} in accordance with {TAIL ~ the outputs} of said sensor means 
a control means including a CPU for controlling { HEAD ~ said wheel driving means } in accordance with { TAIL ~ the outputs } of said sensor means
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH