A Simple Method to Improve Autonomous GPS Positioning for Tractors

Abstract

Error is always present in the GPS guidance of a tractor along a desired trajectory. One way to reduce GPS guidance error is by improving the tractor positioning. The most commonly used ways to do this are either by employing more precise GPS receivers and differential corrections or by employing GPS together with some other local positioning systems such as electronic compasses or Inertial Navigation Systems (INS). However, both are complex and expensive solutions. In contrast, this article presents a simple and low cost method to improve tractor positioning when only a GPS receiver is used as the positioning sensor. The method is based on placing the GPS receiver ahead of the tractor, and on applying kinematic laws of tractor movement, or a geometric approximation, to obtain the midpoint position and orientation of the tractor rear axle more precisely. This precision improvement is produced by the fusion of the GPS data with tractor kinematic control laws. Our results reveal that the proposed method effectively reduces the guidance GPS error along a straight trajectory.

Analytical method of examining the curvilinear motion of a four-wheeled vehicle

“…The tractor-robots are also designed that work without a driver using the remote control [6,7]. In order to accurately determine position of a tractor on the field, a technique is proposed to eliminate errors in the motion via a GPS-receiver [8]. A model is devised to control a tractor Отримано рівняння траєкторії руху чоти-рьохколісної машини в параметричній формі у функції кута повороту остова машини.…”

Development of an RTK-GPS Positioning Application with an Improved Position Error Model for Smartphones

“…These application areas estimate more accurate positions and posture values, by applying a state estimation filter such as the Kalman Filter [2,3,15–17] to the NRTK positioning coordinate, instead of using the direct NRTK measurements. This study proposed a method for determining the error model of the NRTK positioning coordinate, applied to the state estimation filter and the developed error model and Kalman Filter were included in the NRTK application.…”

Merge Fuzzy Visual Servoing and GPS-Based Planning to Obtain a Proper Navigation Behavior for a Small Crop-Inspection Robot

“…The use of a RTK-GPS receiver as the only positioning sensor for the automatic steering system of agricultural vehicles has been examined in several previous studies [ 10 , 11 ]. Furthermore, recent studies [ 12 , 13 ] evaluate the use of low-cost GPS receivers for the autonomous guidance of agricultural tractors along straight trajectories.…”