Alignment control system particularly suited to control traveling

Abstract

An electrical strain gauge is mounted to respond to movements between two sections of a structure. The gauge is mounted on a surface that deforms in response to mis-alignment of the sections in a selected plane. The mis-alignment or the deflection is detected electronically utilizing the strain gauge and the degree of deformation, mis-alignment, or flexure is monitored. Upon reaching selected magnitudes in either direction, signals are generated which may be used to control the amount of deflection. When utilized to control the alignment of sections of a traveling irrigation system, the strain gauge is attached to a bar between adjacent sections which bar flexes upon mis-alignment of sections in the horizontal plane. A pair of electrical sensors monitor the deflection but only one is permitted to generate a signal. A switching circuit selects the appropriate signal generator depending on the direction of travel of the equipment. One such circuit determines the phase sequence of the three phase AC power which sequence may be varied to change the direction of the system travel. The circuit converts the signals from two of the AC phases into two series of pulses. The existence or nonexistence of overlap between the individual pulsesof the two series is dependent and indicative of the phase relationship and used to trigger a flip-flop. This phase detector may be used apart from the misalignment control system. The signal starts or stops a drive motor on one of the sections to realign the sections. A pair of monitors act as a safety interlock to shut down the system if the deflection is excessive in either direction.