scholarly journals A Design of an Unmanned Electric Tractor Platform

Agriculture ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 112
Author(s):  
Yung-Chuan Chen ◽  
Li-Wen Chen ◽  
Ming-Yen Chang

The tractor is a vehicle often used in agriculture. It is mainly used to tow other unpowered agricultural machinery for farming, harvesting, and seeding. They consume a lot of fuel with emissions that often contain a large amount of toxic gases, which seriously jeopardize human health and the ecological environment. Therefore, the electrical tractor is bound to become a future trend. The objective of this study is to design and implement a lightweight, energy-saving, and less polluting electric tractor, which meets the requirements of existing smallholder farmers, equipped with unmanned technology and multi-functions to assist labor and to provide the potential for unmanned operation. We reduced the weight of the tractor body structure to 101 kg, and the bending rigidity and torsional rigidity reached 11,579 N/mm and 4923 Nm/deg, respectively. Two 7.5 kW induction motors driven by lithium batteries were applied, which allows at least 3.5 h of working time.

2019 ◽  
Vol 10 (1) ◽  
pp. 7 ◽  
Author(s):  
Xue Wang ◽  
Chunbin Gao ◽  
Meng Sun

Lithium batteries are widely used in energy storage power systems such as hydraulic, thermal, wind and solar power stations, as well as power tools, military equipment, aerospace and other fields. The traditional fusion prediction algorithm for the cycle life of energy storage in lithium batteries combines the correlation vector machine, particle filter and autoregressive model to predict the cycle life of lithium batteries, which are subjected to many uncertainties in the prediction process and to inaccurate prediction results. In this paper, a probabilistic prediction algorithm for the cycle life of energy storage in lithium batteries is proposed. The LS-SVR prediction model was trained by a Bayesian three-layer reasoning. In the iterative prediction phase, the Monte Carlo method was used to express and manage the uncertainty and its transitivity in a multistep prediction and to predict the future trend of a lithium battery’s health status. Based on the given failure threshold, the probability distribution of the residual life was obtained by counting the number of particles passing through the threshold. The wavelet neural network was used to study the sample data of lithium batteries, and the mapping relationship between the probability distribution of the residual life of lithium batteries and the unknown values were established. According to this mapping relation and the probability distribution of the residual life of lithium batteries, the health data could be deduced and then iterated into the input of the wavelet neural network. In this way, the predicted degradation curve and the cycle life of lithium batteries could be obtained. The experimental results show that the proposed algorithm has good adaptability and high prediction efficiency and accuracy, with the mean error of 0.17 and only 1.38 seconds by average required for prediction.


2016 ◽  
Vol 87 (4) ◽  
pp. 424-432 ◽  
Author(s):  
Julie Peiffer ◽  
KyoungOk Kim ◽  
Masayuki Takatera

The effect of yarn torsional rigidity was verified on the Cooper model for fabric bending rigidity in any direction. We made five cotton fabrics with different weft densities and prepared three commercial fabrics as experimental samples. The torsional rigidity of yarn from the bobbin and that of yarn directly extracted from fabric were measured with a yarn torsional tester. The bending rigidity of yarn from the bobbin was measured using the same pure bending tester as used in fabric bending testing. The bending rigidity of thin fabric was calculated using torsional rigidities of yarns extracted from the fabric and showed better agreement with the experimental values than that calculated using the torsional rigidity of yarn from the bobbin. Indeed, measurements showed that the torsional rigidity of yarn from the bobbin was appreciably higher than the torsional rigidity of yarn from the fabric. This is due to the crimp in the yarn. The fabric bending rigidity can be predicted using the Cooper model with torsional rigidities of yarns extracted from the fabric.


2014 ◽  
Vol 1077 ◽  
pp. 177-184 ◽  
Author(s):  
Hong Xia Zhou ◽  
Bin Liu

To study structural characteristics of flying-wing vehicle, static and dynamic model of half wing span, static and dynamic model of all wing span, optimization model were established. Based on associated static test and ground resonance test data, these models were modified to implement static, dynamic and optimization analysis. Results demonstrated that structural bending and torsional deformations are mainly at outer wing surface. Torsion at inner wing is positive, while torsion at outer wing is negative. Total spar axial force along the wing span increases gradually from inner wing to outer wing and then decreases gradually after reaching the inner-outer wing interface. After axial force is transmitted to the inner wing, it is going to concentrate at the rear spar obviously. Structural bending rigidity and torsional rigidity satisfy requirements of both static force and flutter, without flutter problem of main structural mode. Viewed from the optimization size, ±45° and 0° skin at inner-outer wing turn thickens significantly. This can increase structural bending and torsional rigidity, which is good for satisfying multiple constraints comprehensively.


2014 ◽  
Vol 884-885 ◽  
pp. 178-181
Author(s):  
Bing Wang ◽  
Shou Hui Tong ◽  
Song Han ◽  
Yi Xiao ◽  
Xing Wei ◽  
...  

With the improvement of industrial technology level there are more and more special water quality in the waste water, this bring great difficulties to the water treatment, and the water environment has been an unprecedented severe challenges , especially in some industrial cities. This not only endanger the safety of nearby residents drinking water, even threatening the whole ecological environment. There are some people proposed TiO2 photocatalysis oxidation technology in wastewater treatment may play an important role, so it has been a hot issue in the field of science and technology research.


2011 ◽  
Vol 317-319 ◽  
pp. 287-291 ◽  
Author(s):  
Da Ye Yu ◽  
Gui Lan Yu

Abstract Based on the thin plate theory and the transfer matrix method, the vibration propagation in periodical orthotropic single-leaf rib-stiffened panels is studied. The localization factors of the ordered and disordered periodic systems are calculated. The numerical results show that the anisotropy of the plate affects the propagation of vibration in the pannels. With the relative bending rigidity increasing, or with the relative torsional rigidity increasing, the width of stopbands increases in low dimenionless frequencies. The vibration localization phenomenon occurs in the span-length disordered periodic structures and it is enhanced with the increasing disorder of span-length.


2020 ◽  
Vol 1 (3) ◽  
pp. 101-106
Author(s):  
Kwangtae Ha

In this paper, a simple but effective trailing edge flap system was proposed. This preliminary concept uses a more practical and stable actuation system which consists of a motor-driven worm gear drive and flexible torsion bar. The flexible torsion bar is designed to be easily twisted while keeping bending rigidity as a sup-port and the worm gear drive not only provides a high torque to overcome aero-dynamic forces on the flap area and the torsional rigidity of the support bar, but also acts as a brake to avoid instability due to the high torsional flexibility of sup-port bar. A preliminary level design study was performed to show the applicability of the new trailing edge flap system for wind turbine rotor blade or helicopter blade.


2016 ◽  
Vol 38 ◽  
pp. 73-87 ◽  
Author(s):  
Nataliya A. Sakharova ◽  
André F.G. Pereira ◽  
Jorge M. Antunes ◽  
José Valdemar Fernandes

The study of the mechanical behaviour of single-walled carbon nanotube heterojunctions has been carried out, implementing nanoscale continuum approach. A three-dimensional finite element model is used in order to evaluate the elastic behaviour of cone heterojunctions. It is shown that the bending rigidity of heterojunctions is sensitive to bending conditions. The torsional rigidity does not depend on torsion conditions. Both rigidities of the heterojunction are compared with those of the thinner and thicker constituent nanotubes.


Author(s):  
Aisa Biria ◽  
Eliot Fried

A generalization of the Euler–Plateau problem to account for the energy contribution due to twisting of the bounding loop is proposed. Euler–Lagrange equations are derived in a parametrized setting and a buckling analysis is performed. A pair of dimensionless parameters govern buckling from a flat, circular ground state. While one of these is familiar from the Euler–Plateau problem, the other encompasses information about the ratio of the torsional rigidity to the bending rigidity, the twist density and the size of the loop. For sufficiently small values of the latter parameter, two separate groups of buckling modes are identified. However, for values of that parameter exceeding the critical twist density arising in Michell's study of the stability of a twisted elastic ring, only one group of buckling modes exists. Buckling diagrams indicate that a loop with greater torsional rigidity shows more resistance to transverse buckling. Additionally, a twisted flexible loop spanned by a soap film buckles at a value of the twist density less that the value at which buckling would occur if the soap film were absent.


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