Feasibility of low-cost GPS receivers for ground speed measurement

Keskin, Muharrem; Say, Sait M.

doi:10.1016/j.compag.2006.07.001

Cited by 21 publications

(19 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Usually, expensive RTK-CDGPS are used in the scientif ic literature (Noguchi et al, 1998;Reid et al, 2000;Thuillot et al, 2002;Lenain et al, 2006;Gan-Mor et al, 2007). Only few articles (Guo and Zhang, 2004;Peters and Evett, 2005;Keskin and Say, 2006) have used this kind of receiver for obtaining the position of an irrigation system (Peters and Evett, 2005), measuring the speed of a vehicle (Keskin and Say, 2006), or the guidance of an off-road vehicle (Guo and Zhang, 2004;Price and Nistala, 2005). In this article, the complete guidance system has been implemented and static and relative errors have been studied obtaining clear results.…”

Section: Discussionmentioning

confidence: 99%

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

Alonso-Garcia¹,

Gómez-Gil²,

Arribas³

2011

Span. j. agric. res.

View full text Add to dashboard Cite

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.

show abstract

Section: Discussionmentioning

confidence: 99%

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

Alonso-Garcia¹,

Gómez-Gil²,

Arribas³

2011

Span. j. agric. res.

View full text Add to dashboard Cite

show abstract

“…This is not only because of the deficient applicability of potential alternatives either due to the limitation to fixed routes (stopwatch over a known distance), a lack of continuity in the data capturing with measuring only single points in the movement (laser speed guns), the price (video motion analysis) or the lack of usability for pedestrians, and the dependence on different ground surfaces (e.g. radar sensors (Keskin & Say, , p. 37)). In contrast, the advantages of GPS data loggers include a high spatial accuracy and temporal resolution (Bauder, , p. 424), and accuracy in determining velocity.…”

Section: Gps Supported Speed Analysismentioning

confidence: 99%

“…Witte and Wilson (, p. 1897) stated that neither the HDOP up to a value of forty, the speed itself, nor extended shading areas with four or more satellites in sight, have a significant impact on the accuracy of the velocity measurement. The number of satellites and multipath propagation were also stated as unproblematic in the context of corresponding studies (Witte & Wilson, ; Keskin & Say, ). However, in the densely populated urban areas used in this study, one argument has to be reconsidered.…”

Section: Gps Supported Speed Analysismentioning

confidence: 99%

“…GPS-based velocity measurement is up to date mainly in the matter of research in the fields of precise farming (Keskin & Say, 2006), sports science (Barbero-Àlvarez et al, 2010;Portas et al, 2007;Coutts & Duffield, 2010), and applied medical research (Wettstein, 2012;La Faucheur et al, 2008;Barzilay et al, 2011). The experiences formulated in these contexts will be incorporated in the following chapter.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Using GPS Supported Speed Analysis to Determine Spatial Visitor Behaviour

Bauder

2014

Journal of Tourism Research

View full text Add to dashboard Cite

In this paper a new approach to determine spatial visitor behaviour using GPS-based measurement of tourists' velocity is given. I prove that GPS-based velocity measurement is valid and feasible, even in urban areas. Furthermore, I illustrate that the possibility to interpret spatial visitor behaviour, as well as the choice of transportation type, can be drawn out of the recorded data. The suggested procedure delivers several benefits for destination and tourism management, given that the knowledge of spatial visitor behaviour is central to a successful and sustainable destination management. As an example, two studies (Freiburg, Berlin) are presented in this paper.

show abstract

“…Keskin and Say (2006) found a strong relationship between average GPS speeds and average calculated speeds (R 2 [ 0.99); however, they did not use a separate speed sensor and calculated the speed as the distance divided by time. On the other hand, Koc et al (2006) reported that the speeds obtained from a GPS receiver were about 1.25 km h -1 less than the true speed values.…”

Section: Introductionmentioning

confidence: 95%

Performance of two low-cost GPS receivers for ground speed measurement under varying speed conditions

2016

Self Cite

View full text Add to dashboard Cite

A global positioning system (GPS) receiver is an important sensor used in modern farming, particularly in precision agriculture to determine geographic location and ground speed. The aim of this study was to investigate the effectiveness of two low-cost GPS receivers for measuring ground speed under varying speed conditions on four different dates. A rotary shaft encoder on an auxiliary wheel mounted on an agricultural tractor was used as a reference. A significant time lag between the rotary encoder speed and the GPS speed was found over a range of speeds. It was observed that the GPS speed lagged the encoder speed in both increasing and decreasing speeds. The average time lag was found to be between 3.6 and 5.2 s for Receiver 1 while Receiver 2 had a time lag from 1.7 to 2.5 s. A significant difference was found between the two receivers for increasing and decreasing speeds in terms of time lags (P \ 0.05). A post correction by shifting the GPS speed increased the accuracy of the speed measurement capability of both receivers resulting in an average correlation coefficient of 0.30-0.90 for Receiver 1 and 0.65-0.98 for Receiver 2. Effect of USB-to-COM converter was also studied and it did not have a significant effect on time delay. The GPS receivers provided reliable data during constant speed operating conditions; however, caution should be exercised in varying speed conditions when using low-cost GPS receivers. Also, the companies that produce GPS-based speed sensors should supply technical specifications related to velocity estimates during acceleration and deceleration.

show abstract

Feasibility of low-cost GPS receivers for ground speed measurement

Cited by 21 publications

References 5 publications

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

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

Using GPS Supported Speed Analysis to Determine Spatial Visitor Behaviour

Performance of two low-cost GPS receivers for ground speed measurement under varying speed conditions

Contact Info

Product

Resources

About