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