Gang Angle Research Articles

Predicting the Power Requirement of Agricultural Machinery Using ANN and Regression Models and the Optimization of Parameters Using an ANN–PSO Technique

Optimizing the design and operational parameters for tillage tools is crucial for improved performance. Recently, artificial intelligence approaches, like ANN with learning capabilities, have gained attention for cost-effective and timely problem solving. Soil-bin experiments were conducted and data were used to develop ANN and regression models using gang angle, velocity ratio, soil CI, and depth as input parameters, while tractor equivalent PTO (PTOeq) power was used as an output. Both models were trained with a randomly selected 90% of the data, reserving 10% for testing purposes. In regression, models were iteratively fitted using nonlinear least-squares optimization. The ANN model utilized a multilayer feed-forward network with a backpropagation algorithm. The comparative performance of both models was evaluated in terms of R2 and mean square error (MSE). The ANN model outperformed the regression model in the training, testing, and validation phases. A well-trained ANN model was integrated with the particle-swarm optimization (PSO) technique for optimization of the operational parameters. The optimized configuration featured a 36.6° gang angle, 0.50 MPa CI, 100 mm depth, and 3.90 velocity ratio for a predicted tractor PTOeq power of 3.36 kW against an actual value of 3.45 kW. ANN–PSO predicted the optimal parameters with a variation between the predicted and the actual tractor PTOeq power within ±6.85%.

Research on the safety control technology of gob-side entry in inclined thick coal seam

To study the safety control technology of the gob-side entry in an inclined thick coal seam, the asymmetric deformation characteristics and control mechanism of the gob-side entry in an inclined thick coal seam were analysed by combining theoretical analyses, numerical simulations and field monitoring with the prototype of a gob-side entry in a deep inclined thick coal seam in a high gas mine in Xinjiang. The research results showed that the deformation of the solid coal gang and top plate is more intense than that of the narrow coal pillar gang and bottom plate. Combined with the asymmetry of deformation surrounding rock, the gob-side entry safety control technology based on a high prestressing high-strength anchor support and a reinforced support by inclined anchor cables in key areas (a zero-displacement area within the narrow coal pillar and an intense deformation area of the solid coal gang angle) is proposed. Reasonable the gob-side entry support parameters were further determined via numerical simulation experiments, and a reasonable anchor length, row spacing and spacing to maintain the stability of the gob-side entry were obtained as 2200 mm, 800 mm and 800 mm, respectively. Engineering practice showed that the adoption of the new support technology can effectively control the asymmetric large deformation of the solid coal gang and top plate, which can maintain the stability of the gob-side entry for a long period of time and ensure the safe and efficient production of coal resources in the mine.

Draft force prediction for a high-speed disc implement using discrete element modelling

Draft force is an important dynamic parameter for agricultural soil-engaging tools and implements. Soil-disc interaction dynamics has changed enormously in modern tillage practice because of the use of larger machines, faster speeds, and different tool arrangements. Most existing studies on draft force prediction are for conventional tillage. In this study, a discrete element model (DEM) was developed to predict draft forces for high-speed (12 km h−1 or higher) tillage. Draft forces were measured for an individually mounted disc using soil bin tests at low speeds in a sandy loam soil. Results were compared for the accuracy with the predicted values from the ASABE standard equation. Results showed that relative error ranged from 8% to 14%. Due to the limitations of the testing facility, the DEM model was calibrated using 6 km h−1 tillage speed and verified with other test speed measurement. The calibrated model was able to predict draft force with a minimum relative error of 1%. The calibrated particle stiffness, was found to be 20 kN m−1. The calibrated model was then used to examine the effects of operating parameters including gang angle, tilt angle, operating speed, disc diameter and tillage depth on draft forces at 16 km h−1. From these simulations, it was shown that draft increased with an increase in gang angle, tillage depth, and speed. The draft force was reduced with an increase in tilt angle and remained relatively constant with the change of disc diameter. Finally, the simulated data were used to develop a multivariate regression equation to predict the draft for a high-speed tillage operation. This equation is suitable for the soil conditions studied and further validation is required to verify this equation.

Specific draft estimation model for offset disc harrows

Predicting draft requirements of tillage implements is essential from the viewpoint of proper tractor-implement matching and machinery design. It was hypothesized that draft requirement of offset disc harrow (ODH), a widely used tillage implement depends mainly on four major soil and working parameters, i.e. soil cone index (CI), forward speed, working depth and front gang angle (FGA), which could be used to develop a reasonable regression model for estimating its specific draft. To test this hypothesis, investigations were carried out on the draft requirement of ODH in an indoor soil bin available at Indian Institute of Technology, Kharagpur (22°19′ N, 87°19′ E), India during the months of November 2016 to May 2017. The soil available in the soil bin was acid lateritic sandy clay loam and taxonomically grouped under order Alfisol (Oxyaquic haplustalf). The experimental design was completely randomized with draft measured using S-type load cell (2-tonne capacity) at four levels each of FGA and forward speed, three levels each of working depth and soil CI using a 3 × 3 ODH (i.e. 3 discs in each of the two gangs) with the objective to acquire data on the draft force requirement of ODH at various soil and working parameters. The forward speed, working depth, and soil CI were measured with the help of a magnetic-type proximity switch, rotary potentiometer, and hydraulic cone penetrometer, respectively and were found to have a significant effect (p ≤ 0.01) on the draft with CI having highest influence followed by working depth, speed, and FGA. Multiple regression analysis was carried out to develop a model for estimating specific draft for ODH. The efficiency of specific draft model, was assessed by various performance indices such as mean error (ME), value account for (VAF), root mean square error (RMSE), coefficient of determination (R2), and mean absolute percentage error (MAPE) and their values were found to be -3.22, 92.77%, 4.82, 0.90 and 14.75, respectively. A major advantage of the developed specific draft model compared to other researchers’ model is the inclusion of all parameters that affect draft especially FGA and CI which would increase its applicability. A good general agreement between measured and estimated specific draft was found with the data obtained from the soil bin with an average absolute variation (AAV) of 10.76%. Verification of the model was also carried out by comparing its outputs with the model outputs of previous researchers to check its applicability for other soil types and working conditions, and the results were found to be fairly good (Al-Janobi and Al-Suhaibani, 1998 (R2 = 0.87, AAV = 14.33%), Kheiralla et al., 2004 (R2 = 0.93, AAV = 11.95%), and Roul, 2014 (R2 = 0.94, AAV = 23.05%) except the ASABE draft model (R2 = 0.66, AAV = 50.18%). Therefore, the developed model in this research could be used to predict draft requirements of ODH’s with reasonable accuracy.

Performance of combined offset disc harrow (front active and rear passive set configuration) in soil bin

Soil bin investigations were initiated with combined offset disc harrow (CODH) which unites the benefits of powered discs and combination tillage together through a front active-rear passive set configuration. The proposed configuration may help to achieve timeliness in sowing, better crop residue handling with reduced tillage passes and improved engine power utilization of tractor. The effects of speed ratio (u/v), front gang angle (α), operating depth and cone index (CI) on its draft, torque and power requirement were studied and compared with its traditional passively driven mode at an average soil moisture of 9–10% (db) in sandy-clay loam soil. Optimum system settings were found out before further performance evaluation in the field. The substantially reduced draft requirement with CODH might help to reduce the wheel slippage and improve field productivity while increased power requirement might prevent the under-loading of tractor engine. Tillage quality was assessed considering CI values and found to be far superior compared to traditional mode. Optimum system settings were found at α of 35° and u/v ratio of 3.6 in terms of lowest power expenditure and better work quality with torque power expenditure of 60–70% in total power indicating improved utilization of engine power if operated with tractor power take-off (PTO).

Soil bin tests and discrete element modeling of a disc opener

Soil disturbance and cutting force are two of the most common performance indicators for openers. These were investigated for a disc opener through measurements in an indoor soil bin and modeling using the discrete element method (DEM). In the soil bin experiments, the disc was tested at a constant depth of 37.5 mm and different tilt angles (0°, 10°, and 20°). Draft and vertical forces, and soil throw caused by the disc were measured. The DEM model was validated using the results from the experiments. The validated model was used to predict soil-cutting forces under various operational parameters. Both the experiments and the model showed an increasing trend of soil throw with the tilt angle. The model produced a decreasing trend for the draft force and vertical force, while the experiments did not show any particular trend. In comparison with the experimental results, the model results had relative errors of 10.5%, 1.9%, and 59.7% in predicting soil throw, draft and vertical forces, respectively. The draft force predicted with the model increased from 9.4 to 74.7 N following a polynomial equation when the gang angle of the disc was varied from 0° to 30°, and from 3.1 to 82.9 N following a polynomial equation as well when the working depth was varied from 12.5 to 75.0 mm. The model was able to produce well-defined trends of draft, vertical, and lateral forces of the disc opener.

Medida do ângulo horizontal de ataque dos discos de grades agrícolas de dupla ação e aplicação a uma propriedade agrícola

O conhecimento do ângulo de ataque de grades agrícolas é importante, pois o mesmo influencia a exigência em força de tração, a profundidade e a qualidade da gradagem. O objetivo deste trabalho foi desenvolver um método de medida do ângulo horizontal, de ataque, dos discos de grades de dupla ação com as seguintes características: rápido, de fácil medida e preciso, para aplicação no local de trabalho das grades. O princípio do método proposto baseia-se no fato de que é possível circunscrever grades de dupla ação em um trapézio isósceles e no teorema da trigonometria no qual ângulos com lados perpendiculares entre si formam ângulos iguais. Assim, o método desenvolvido pode ser enunciado como segue: "o seno do ângulo de ataque de uma grade de dupla ação é igual à diferença entre a base maior e a base menor dividida por duas vezes o lado do trapézio". Dessa forma, três medidas de comprimento realizadas com uma trena, ou seja, base maior, base menor e o lado do trapézio, permitem determinar o valor do seno e, consequentemente, o próprio ângulo de ataque da grade. Foram levantados os ângulos de ataque de onze grades agrícolas de propriedade da Destilaria Londra, de Itaí, estado de São Paulo, comprovando a rapidez e facilidade de utilização do método.

The Effect of Gang Angle of Offset Disc Harrows on Soil Tilth, Work Rate and Fuel Consumption

In offset disc harrows, the angle between gangs may be changed to meet the field conditions. Tractor drivers usually use an angle close to maximum, increasing power requirements and therefore limiting the forward speed and, consequently, the work rate. The objective of this work was to study, in the specific soil conditions present in Southern Portuguese agriculture, the effect of working with a disc harrow at a reduced gang angle and at a higher forward speed, in terms of work rate, fuel consumption per hectare and distribution of dry soil aggregates. A trailed-type medium-weight offset disc harrow (20 discs of 610 mm diameter) was used, pulled by a four-wheel drive tractor. A portable computer-based record system was used to collect engine speed, actual forward speed, slip, fuel consumption and draught force. Higher work rates and lower values of fuel consumption per hectare were attained, with no visible difference in soil tilth, by operating the disc harrow at a lower angle between disc gangs and shifting up to a higher gear ratio whilst maintaining engine speed. Tractor drivers, particularly those with tractors equipped with performance monitors should consider setting, by preliminary tests prior to the main field work, the right combination of gang angle and forward speed within the limits of quality of the work and the safety of the operation.

The Utilisation of Tractor-Mounted Primary Tillage Implements in the Malkerns Valley, Swaziland

The study was primarily aimed at determining the utilization of tractor-mounted primary tillage implements in Swaziland using 14 case study forms in the Malkerns Valley. Being descriptive in nature, the study employed scheduled personal interviews and questionnaires that were developed, pre-tested and administered by the authors. The results showed that the 38 primary tillage implements found on the 14 case study farms were ploughs, disc harrows and rippers or subsoilers forming 44.7%, 34.2% and 21.1% respectively. The predominant makes of these implements were Massey Ferguson, John Deere, S.A. Wonder and Safim, while the others were Case, Leyland, C.G. Tillage and Agri-Tech. It was evident from the results that these implements were selected on the basis of their design, prevailing farm conditions and personal preferences of the farmers. Operation of the implements took place on soil types ranging from sand clays to heavy clays on a total land area of 1461 ha. The operation was aided by a total of 39 tractors of the makes, Massey Ferguson, John Deere, Case, Leyland and Ford. Even though the primary tillage implements were adjusted in the farm and in the field for depth, cutting width, gang angle and tilting angle, it was evident from the results that the majority of the implements were extremely under utilized. UNISWA Research Journal of Agriculture, Science and Technology Vol. 4 (1) 2000: pp 34-43

Effects of PTO-powered disk tilling on some physical properties of Bangkok clay soil

Experiments were conducted to investigate the effects of tilling with a PTO-powered disk tiller on some physical properties of Bangkok clay soil. Tests were conducted at 1, 2, 3, 4 and 5 km h −1 forward speeds and 28° and 33° gang angles. Average moisture content of the soil was 26 g 100g −1. The effects of disk tilling were assessed in terms of changes in bulk density, total porosity, cone index, clod size distribution and soil inversion during the first and second passes. Tests were also conducted in the unpowered mode at a 28° disk gang angle setting during a single pass. The study revealed that the bulk density and cone index were reduced, and the total porosity, content of clods of < 15 mm diameter and soil inversion were increased with an increase in the number of passes and forward speed. At any given pass and forward speed, the reduction in bulk density and cone index, and increase in total porosity and content of clods of < 15 mm diameter, were greater at a 28° disk gang angle setting compared with a 33° setting. More soil inversion was recorded at a 33° than at 28° gang angle setting. A comparison of performance between powered and unpowered modes revealed that, in the unpowered mode, the tilling effects on soil physical properties were less than that obtained in the powered mode.

Power spectral density analysis of draft and torque fluctuations of a PTO powered disk tiller

Experiments were conducted in a typical Bangkok clay soil with a PTO driven disk tiller to collect the draft force and torque variation data. Tests were conducted at different forward speeds of 0.29, 0.59, 0.86, 1.08 and 1.37 m/s and at 28° and 33° disk gang angle settings. Average soil moisture content was 26% and average cone index of the test soil was 1870 kPa during all the tests. The draft force was measured by a three point linkage dynamometer. The PTO torque was measured by a slip ring type torque transducer. Tests were also conducted in the unpowered mode. Fast Fourier transform (FFT) and power spectral density (PSD) analysis techniques were used to analyse the draft force and torque variations in a time domain. The results indicated that the dominant frequencies of the draft force variations were within the range of 2.5–5.5 cycles/m of forward travel. The wave length was longer at a higher disk gang angle setting. The dominant frequency component of the torque variations varied from 3.3 to 4.3 cycles/revolution of the disk. In the unpowered mode the dominant frequencies of the draft signals had less magnitude than those of the powered mode for the same operating conditions at both disk gang angle settings of the powered disk.

Field testing of a PTO powered disk tiller

Field testing of a PTO powered disk tiller was conducted in Bangkok clay soil. Tests were conducted at different forward speeds of 1,2,3,4 and 5 km/h and 33, 28 and 23° gang angles. Average PTO speed was 540 rpm and average soil moisture content was 26% during all the tests. The draft requirement was measured by a three point linkage dynamometer. The PTO torque was measured by a slip ring torque transducer. Specific draft, specific torque, power and energy consumption to till a unit volume of soil were calculated for different gang angle settings during passes 1 and 2. Quality of work was assessed in terms of soil cone index. Better tillage performance was observed at 28° gang angle than at 33°. At 23° gang angle the implement did not penetrate well due to the gage wheel remaining on unplowed soil. It was observed that at 28° gang angle setting, the implement consumed less power compared to the 33° gang angle setting at all forward speeds and passes. It consumed as much as 27% more power at 33° gang angle setting than at 28° gang angle setting. The power consumption decreased with higher passes. The energy consumption was higher at 33° gang angle than at 28°. It was also higher at lower forward speed compared to higher forward speed at any given gang angle setting and pass. The work quality in terms of soil cone index at 28° gang angle was better than at 33° gang angle. Disk tiller performance in unpowered mode was also evaluated. It consumed more draft power during unpowered mode compared to powered mode.

DISK SPACING MODEL FOR OPTIMIZING GANG PERFORMANCE

ABSTRACT The effect of disk spacing and gang angle on gang forces was investigated. Two conventional disk shapes were used at two gang angles. One angle provided soil clearance on the back side of the disk; the other was a commonly used angle which resulted in soil pressure on the back side of the disk. All tests were mn at a speed of 1.3 m/s and a depth of 150 mm. The forces on a disk gang were found to vary linearly with the spacing as disk spacing was varied from 100 to 500 mm. A model was developed which described the soil forces as a function of the number of disks and the spacing of the disks in a gang. Results showed that changing disk spacing significantly changed disk gang forces. The disk gang force model was used to explore possibilities for design of disk harrows for maximum or minimum forces. The model was also used to determine the disk spacing at which no ballast was needed to force the harrow to operating depth.

Factors Affecting Treader Soil Reaction Forces

ABSTRACT Soil reaction forces for three treader designs were measured in the field. The treaders were tested at three operating depths, four forward velocities and seven gang angles. Treader design, operating depth and treader gang angle significantly affected draft, side draft and vertical force. Draft, side draft and vertical force were linearly proportional to operating depth, trigonometric transformations of gang angle, cone index, and inversely proportional to the peripheral velocity squared. Prediction equations were developed relating reaction forces to depth, gang angle, cone index and peripheral velocity.

Effect of Soil and Implement Parameters on Depth of Penetration of a Disc Harrow

ABSTRACT THE effect of various soil, implement and oper-ating parameters on the depth of penetration of a disc harrow was determined. The factors con-sidered were the diameter of the disc, gang angle of the harrow, weight of harrow per disc, speed of operation, cone index of soil and acceleration due to gravity. By using the technique of dimensional analysis total variables were reduced to one dependent and three independent variables. By conducting the ex-periments in the field the relations were developed be-tween different independent variables and one de-pendent variable i.e. depth factor. A composite depth variable factor involving all the three inde-pendent dimensionless terms was developed and a linear relation between the depth factor and com-posite depth variable factor was found.