Computer Simulation for Haulage Performance of Power Tiller
The presence of a large number of marginal and small land holdings in India has rendered the power tiller to be the most suitable farm equipment for field operations, in view of its compact size, profitability and versatility, but the transport work which is also required to carry the farm produce is yet to be proved. Keeping these in mind, user friendly software was developed for predicting the haulage performance of power tiller to meet requirements in educational and research organizations. The developed software requires input parameters such as power tiller, trolley and operating conditions. The developed software was validated by conducting experiments with a 6.7 kW power tiller using a suitable trolley on tarmacadam road at various payloads and road slopes. The draft, slip, fuel consumption and speed were measured and other haulage performance parameters were calculated based on measured values to validate the developed software. The results simulated by software indicate lower draft and slip in the range of 1-23 and 2-9% with respect to the experimental data, however, higher transport productivity was in the range of 3-12%.
Effect of hitch distance on haulage performance for 2WD tractors: A theoretical analysis
Aim of study: A computer program was developed in Visual Basic 10 environment for predicting the haulage performance of 2WD tractors using various empirical and theoretical equations.Methodology: Three types of inputs related to tractor, trailer and operating parameters were used to calculate the performance parameters through empirical and theoretical equations. The performance parameters included mainly draft, slip, transport efficiency, transport productivity, fuel economy index, rear and front axle dynamic weight, etc. The program was used to evaluate the haulage performance by varying hitch distance (HD) at various operating conditions.Main results: On one hand lower HD was beneficial in increasing the maximum payload, transport productivity as well as the maximum slope; but at the same time, it reduced the rear axle dynamic load, fuel economy index and actual engine power requirement.Research highlights: There was a markable effect of HD over tractor performance which can play a role to optimize traction and stability. 
Tractor performance spreadsheet for radial tires
Abstract Lotus-compatible templates were revised from the Zoz (1987) spreadsheets. Performance of two-wheel-drive (2WD) and four-wheel-drive/mechanical-front-wheel-drive (4WD/MFWD) tractors were predicted on agricultural soils for radial tractor tires. Comparisons between the predicted and experimental results of 41 tractors using radial tractor tires showed fair agreement. The performance parameters used in the comparisons were wheel slip, drawbar pull and tractive efficiency. The percentage differences were calculated and the acceptable range was set at 20% difference. For wheel slip, 22 out of 41 tractors had percentage differences that fell within the acceptable range. The drawbar pull comparison showed that 35 out of the 41 tractors had percent differences within the acceptable range. The tractive efficiency comparison showed that 27 out of 33 tractors had percentage differences that fell within the 20% range. The predicted drawbar pull and tractive efficiency were higher than the experimental values in most cases of MFWD tractors. Because some input values for the spreadsheet such as available power, cone index and travel speed were not given in the source of data, the predicted results of tractor performance were not in close agreement to experimental results.