النماذج الرياضية لتوقع قوى السحب لأدوات الحرث : دراسة مراجعة

الملخص EN

tillage play an important aspect in the evolution of agriculture.

Also, it has a direct influence on soil productivity and sustainability.

The function of the tillage includes seedbed preparation, water and soil conservation and weed control.

A large amount of energy is consumed during tillage operations.

Furthermore, the draft force results in frictional and wear losses of the tillage equipment.

Since the cost of energy is high and there are significant energy losses due to the friction and wear, the development of highly efficient tillage tools that require less energy while providing a satisfactory soil environment for seed emergence is of paramount importance .

There is a lack of knowledge in soil conditions required for crop, soil dynamics to apply energy to the soil, to change its state from the original to the desired state and development of control algorithms and tillage transducers.

With increased use of computers, it is possible to model the entire machine- soil – plant system in order to make the analysis of tillage a more deterministic rather than the present stochastic process.

To achieve this goal, the system must be divided into soil – machine sub-model and soil-plant sub model.

Draft force prediction, clod sizes distribution and negative effect of erosion have been some of the motivation topics for studying and modeling soil-tillage interaction.

Data from field process and lab experiments are combined on mathematical models; supporting by the increment on informatics resources more accurate, fasters and extended prognostics are performed (Bravo et al., 2012).

These models can be classified as : 1-Experimental models.

2 -Analytical models.

3 -Numerical model (Finite Element Models) .

On the other hand, Dimensional Analysis Models, and statistical models were also included.in order to recommend one model on the other, it was decided to compare their results with some experimental tests.

Some of the models were succeeded to predict the draft in a range of 40-60%, And they fail in some other conditions.

Wherever the FEM give prediction up to 80-90 % accurate .

Any development in that direction will be rewarded, where it represents the real situation during loading, Where the close relation between soil and tool is thoroughly considered.