Evaluation of the use of low-cost GPS receivers in the autonomous guidance of agricultural tractors

Abstract

This paper evaluates the use of low-cost global positioning system (GPS) receivers in the autonomous guidance of agricultural tractors. An autonomous guidance system was installed in a 6400 John Deere agricultural tractor. A lowcost GPS receiver was used as positioning sensor. Three different control laws were implemented in order to evaluate the autonomous guidance of the tractor with the low-cost receiver. The guidance was experimentally tested with the tracking of straight trajectories and with the step response. The total guidance error was obtained from the receiver accuracy and from the guidance error. For the evaluation of the receiver's accuracy, positioning data from several lowcost receivers were recorded and analyzed. For the evaluation of the guidance error, tests were performed with each control law at three different speeds. The conclusions obtained were that relative accuracy of low-cost receivers decreases with the time; that for an interval lower than 15 min, the error usually remains below 1 m; that all the control laws have a similar behavior and it is conditioned by the control law adjustment; that automatic guidance with lowcost receivers is possible with speeds that went up to 9 km h -1 ; and finally, that the total error in the guidance is mainly determined by the receiver's accuracy.Additional key words: control law; fuzzy logic; inertial navigation system (INS); linear quadratic regulator; step response; trajectory tracking. Resumen Evaluación del uso de receptores GPS de bajo coste en el guiado autónomo de tractores agrícolasEste artículo evalúa el uso de receptores de posicionamiento global (GPS) de bajo coste en el guiado autónomo de tractores agrícolas. Para ello, se instaló un sistema de guiado autónomo en un tractor John Deere 6400. Como sensor de posicionamiento se utilizó un único receptor GPS de bajo coste. Se implementaron tres leyes de control diferentes para la evaluación del guiado con el receptor GPS de bajo coste. Se realizaron pruebas de seguimiento de trayectorias rectilíneas y de respuesta escalón. El error de guiado total se obtuvo de la precisión del receptor y del error relativo instantáneo en el seguimiento de una trayectoria. Para la evaluación de la precisión del receptor, se tomaron y analizaron datos de posición de varios receptores. Para la evaluación del error en el guiado, se realizaron pruebas con cada una de las leyes de control a tres velocidades diferentes. Como conclusiones se ha obtenido que la precisión relativa de los receptores GPS de bajo coste disminuye con el tiempo; que en un intervalo de tiempo inferior a 15 min, la precisión relativa es aproximadamente 1 m; que el comportamiento de las diferentes leyes de control es similar y está condicionado por el ajuste de las mismas; que el guiado es posible a velocidades de hasta 9 km h -1 y, finalmente, que el error total en el guiado está principalmente determinado por la precisión del receptor.

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.…”

“…Regarding the type of vehicle, most studies of the autonomous guidance of agricultural vehicles have focused on tractors or heavy vehicles [ 10 , 12 , 13 , 15 , 17 , 20 , 21 , 22 , 23 , 24 , 26 ]. Moreover these large vehicles can autonomously navigate along the crop rows, but they are unable to autonomously cover an entire crop by performing the necessary manoeuvres for switching between crop rows.…”

Modeling sprinkler irrigation infiltration based on a fuzzy-logic approach

“…The aggregation method is explained as the max (maximum) composition. Finally, the center of gravity (COG) was calculated; this is the most popular defuzzification method for obtaining the real-valued (crisp) output as a normalized combination of membership values (Jantzen, 1999;Allahverdi, 2002).…”

“…Fuzzy logic has been used to control the steering of a tractor (Alonso-Garcia et al, 2011), to design fuzzy databases, to store and process environmental (mainly on soils) and agricultural data (Delgado et al, 2008).…”

Contribuciones al desarrollo de un sistema efectivo para la inspección de cultivos

“…El uso de un receptor GPS-RTK como único sensor de posicionamiento para el guiado de vehículos agrícolas se ha examinado en varios estudios (Stoll & Kutzbach, 2000), (Blackmore, Griepentrog, Nielsen, Nørremark, & Resting-Jeppesen, 2004). Es más, varios autores evalúan el uso de receptores GPS de bajo coste para el guiado de vehículos agrícolas (Rovira-Más, Chatterjee, & Sáiz-Rubio, 2015), (Gomez-Gil, Alonso-Garcia, Gómez-Gil, & Stombaugh, 2011), (Alonso-Garcia, Gomez-Gil, & Arribas, 2011).…”