The PID controller generates {HEAD ~ a command signal} to either modulate the brakes or motor up or down depending on {TAIL ~ the sign} of the command signal 
The PID controller generates { HEAD ~ a command signal } to either modulate the brakes or motor up or down depending on { TAIL ~ the sign } of the command signal
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH