INFRA-RED POSITION SENSOR SYSTEM

摘要

A sensor system applicable to agricultural booms (16) to control extension so as to enable work heads (46, 60) to be extended between trees off a vehicle travelling parallel to a row of trees with an infra-red detector (75) operative to detect reflection of a pulsed infra-red signal off a nearby tree trunk to signal need to withdraw boom. The sensor system indicates approach of the boom to within a selectable distance of the tree trunk by detecting the level of the reflected pulse.