The device takes a weighted average of output signals from the two sensors, using weighting factors that, in one embodiment, are applied either electronically and are selected either as proportional to the lengths of the member regions under the influence of the actuator and not under the influence of the actuator, or are selected to provide a desired transfer function between input to the actuator and {HEAD ~ output} from {TAIL ~ the sensing device} 
The device takes a weighted average of output signals from the two sensors , using weighting factors that , in one embodiment , are applied either electronically and are selected either as proportional to the lengths of the member regions under the influence of the actuator and not under the influence of the actuator , or are selected to provide a desired transfer function between input to the actuator and { HEAD ~ output } from { TAIL ~ the sensing device }
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 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 OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL