Parallelism error in peanut sowing operation with auto-steer guidance

Abstract

A B S T R A C TGNSS positioning errors are certain, regardless of the adopted positioning method. In agriculture, these errors may represent higher or lower overlapping rates between passes of a mechanical assembly, affecting operation quality. Therefore, this study evaluated the main errors arising from peanut sowing operation performed with an auto-steer guidance system by an RTX signal, using the Statistical Process Control techniques. The errors evaluated were: in tractor lateral displacement, project execution, and parallelism between passes of tractor-seeder set. The average errors of project execution in all passes were within the range specified by the manufacturer, i.e. lower than 3.8 cm. The average error of tractorseeder set was also within the accepted range. However, as shown in control charts, lateral tractor displacement had interference of terrain slope, causing average errors higher than the accepted range. Based on the control charts, project execution accuracy was satisfactory, and it is possible to use the RTX signal in agricultural operations that require accuracy lower than 3.8 cm, such as peanut sowing.Erros de paralelismo provenientes da operação de semeadura de amendoim com direcionamento automático R E S U M O Os erros de posicionamento pelo GNSS são inevitáveis, independentemente do tipo de posicionamento adotado. Na agricultura esses erros podem representar maior ou menor taxa de sobreposição entre as passadas dos conjuntos mecanizados, o que afeta, consequentemente, a qualidade da operação. Objetivou-se, neste sentido, avaliar os principais erros ocasionados durante a operação de semeadura de amendoim utilizando direcionamento automático com sinal RTX, por meio da análise do Controle Estatístico de Processo. Foram avaliados o erro de deslocamento do trator, o erro de execução do projeto, em quatro passadas, além do erro de paralelismo entre as passadas do conjunto tratorsemeadora. O erro médio de execução ficou, em todas as passadas, dentro do estipulado pelo fornecedor do sinal, com valores menores que 3,8 cm. O erro médio do conjunto trator-semeadora encontrou-se no limite do aceitável. Já para o deslocamento lateral do trator, pela análise das cartas de controle, houve interferência da declividade na ocorrência de erros acima do estipulado. Com base na análise das cartas de controle constata-se que houve precisão para o erro de execução de projeto e que é possível utilizar o sinal RTX em operações agrícolas que requerem precisão menor que 3,8 cm, como a semeadura de amendoim.

Position Errors in Sowing in Curved and Rectilinear Routes Using Autopilot

“…When working with specific limits in the control charts (SL), these should receive special attention, since they are the ones that will guarantee the quality in the monitoring process, indicating if there was precision in the positioning of GNSS signal-guided machines during field operation, so that when all points are between the SL indicates high accuracy and accuracy in positioning (Santos et al, 2017). Considering this information, it can be said that the use of the satellite signal for the steering of mechanized set did not provide a sowing with precision and accuracy, having points that extrapolate the control limits, in the two routes.…”

“…However, errors of up to 3.8 cm do not interfere with the overlapping rate in the peanut sowing operation, which makes the RTX signal an interesting alternative to the producer who wishes to make a precise sowing, as attested by Santos et al (2017), in rectilinear paths.…”

“…The accuracy of the sowing operation using the RTX Center point signal can be compared with the results found by Berning (2011), who tested soil preparation equipment coupled to an automatic steering vehicle (RTK) and found a reduction in the overlap rate increasing steering accuracy between 5 to 6 cm in comparison to manual steering. Santos et al (2017) evaluated the RTX signal in a straight course, and concluded that one of the main factors that affect the positioning of the tractor is the type of coupled implement, where it can cause greater or lesser lateral sliding. Lipinski et al (2016) evaluated different types of GNSS signals (paid signal SF1 and SF2, free and manual signal) and found significant differences in relation to the overlap, so that when adopting a paid signal for the direction of the machines the error reduces.…”

“…Then the correction is sent to a geostationary satellite that retransmits to all the receivers that are within reach, which in turn make the correction of the positioning of the machines in the field, with guarantee precision of ± 3.8 cm, according to the supplier of the sign (Trimble, 2017). This signal was evaluated by Rizos et al (2012) and Santos et al (2017) where it guaranteed horizontal accuracy of 4 cm in 95% of the observations with a time of initiation of 1 minute. Carballido et al (2014) also demonstrated the efficiency of the signal in autonomous vehicles in rectilinear path.…”

Tillage Interference in the Quality of Peanut Mechanized Harvest

“…In this context, the Statistical Process Control (SPC) is included as a useful and commonly used tool in the analysis of the agricultural processes quality. Several authors have used the SPC, considering the variables evaluated as quality indicators, to identify nonrandom causes or special causes arising fro m the instability or variability due to the process (Toledo et al, 2013, Paixão et al, 2017Santos et al, 2017;Zerbato et al, 2017), however, there are no studies evaluating the quality of the peanut harvesting operation in different types of soil preparation.…”