{HEAD ~ The system} comprises a closed loop controller, {TAIL ~ a towing arm assembly}, a load measuring device, an electric hub motor, brakes, a motor controller and a brake controller disposed on the trailer 
comprises
{ HEAD ~ The system } comprises a closed loop controller , { TAIL ~ a towing arm assembly } , a load measuring device , an electric hub motor , brakes , a motor controller and a brake controller disposed on the trailer
HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH