Further, a lateral drive supported by the travel unit is controlled by a lateral control unit, and {HEAD ~ a θ drive} supported by {TAIL ~ the lateral drive} is controlled by a θ control unit 
Further , a lateral drive supported by the travel unit is controlled by a lateral control unit , and { HEAD ~ a θ drive } supported by { TAIL ~ the lateral drive } is controlled by a θ control unit
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH