Patent ID: 9164177
Filing Date: 2015-10-20
Classification: A01G,G01C,G01S,G05D

Abstract:
1. A mechanized corner irrigation system, which is part of a center pivot irrigation system, for irrigating a field having navigation latitude and longitudinal waypoints which correspond to the correct latitude and longitudinal position of the steerable drive unit of the corner irrigation system as it moves around the field, comprising: said center pivot irrigation system comprising a center pivot structure, a main arm extending outwardly from said center pivot structure which is supported upon and driven in either a forwardly or rearwardly direction around the field by a plurality of non-steerable drive units; said corner irrigation system comprising an elongated corner arm pivotally secured to the outer end of said main arm and supported upon and driven by said steerable drive unit; said steerable drive unit comprising: a rover navigation box positioned on said steerable drive unit; said rover navigation box including a GNSS receiver mounted on a printed circuit board; a rover GNSS antenna mounted on said steerable drive unit which is in communication with said GNSS receiver in said rover navigation box; said latitude and longitudinal navigation waypoints being programmed in said rover navigation box; said rover navigation box operatively connected to said steering actuator to control the operation of said steering actuator; a base navigation box positioned on said center pivot irrigation system at said center pivot structure; said base navigation box including a GNSS receiver mounted on a printed circuit board; a base GNSS antenna mounted on said center pivot irrigation system at said center pivot structure which is in communication with said GNSS receiver in said base navigation box; said base navigation box configured to compute its latitude and longitudinal position utilizing RTK to send corrections to said rover navigation box whereby said rover navigation box continuously computes its corrected latitude and longitudinal position as said steerable drive unit moves around the field whereby the corrected latitude and longitudinal position of said steerable drive unit is compared to the two closest navigation latitude and longitudinal waypoints to determine the steering direction of the steering actuator and the amount of steering time based on a steering formula incorporating cross track error and wheel angle error to ensure that the steerable drive unit stays on its intended path.