Abstract: An irrigation system with steady state speeds of movement achieves and maintains substantial straight alignment of multiple interconnected spans with continuous movement over a range of speeds in a forward and reverse movement direction. A variable-speed drive controller monitors and processes the output of the corresponding alignment detector and, based on the output of the alignment detector, selects from memory and continuously furnishes to the corresponding span motor a predetermined progressively increasing speed profile, a predetermined progressively decreasing speed profile, or a new fixed current speed.

Abstract: An irrigation system with transient state speeds of movement achieves and maintains substantial straight alignment of multiple interconnected spans with continuous movement over a range of speeds in a forward and reverse movement direction. A variable-speed drive controller monitors and processes the output of the corresponding alignment detector and, based on the output of the alignment detector, selects from memory and continuously furnishes to the corresponding span motor a predetermined progressively increasing speed profile or a predetermined progressively decreasing speed profile.

Abstract: An irrigation system with an alignment detector uses a plurality of discrete sensors to detect and measure each irrigator span's misalignment when moving in either direction. In particular, this sensor alignment detector utilizes a first sensor for the forward movement direction and a second sensor for the reverse movement direction, which provides a significant improvement in alignment optimization and sensitivity.