Designing a Control System for Grain Combine Platform Loss

The consumption of cereals, especially wheat, is increasing consistently in the world which is attributed to the population growth. Therefore, increasing its production through reduction of the losses is very important. Noticeable proportion of produced wheat losses occur during production and consumption steps and the loss due to harvesting with combine harvester is regarded as one of the main factors. A grain combine harvester consists of different sets of equipments and one of the most important parts is the header which comprises more than 50% of the entire harvesting losses. Thus, any effort for reducing the grain loss is economically important. Reduction of losses due to cutting platform of the combine is one of the main and principle works in decreasing the combine losses. Losses from combine harvesters are attributed to two main factors, the condition of the crop itself and the working condition of the combine harvester. To reduce grain losses, the operator must know the source of losses and how to measure it. If the grain losses are not acceptable, the operator must reduce them by adjusting the components. The losses from improperly adjusted combines can be quite significant.

In this study, the focus is on the tuning, proper adjustment and control of the setting parameters of the combine header to achieve minimal grain losses. Forward speed, peripheral reel speed, cutting height, horizontal and vertical distance of reel tine bar from cutter bar are regarded as the controlled factors in this study. Each factor has three levels (i.e. for the forward speed: 2, 2.5 and 3 kmh^-1, for the peripheral reel speed: 2, 3 and 4.5 kmh^-1, for the cutting height: 25, 30 and 35 cm, for the horizontal distance of reel tine bar from cutter bar: 0, 5 and 10 cm and for the vertical distance of reel tine bar from cutter bar: 5, 10 and 15 cm). Experimental results are used to design a proper control system for adjusting header setting to obtain the minimum gathering loss. In this study, a controller system will be designed to achieve automatic settings of the combine header.

Control system provides a formal methodology for representing, manipulating and implementing heuristic knowledge of humans in combination with experimental model-based knowledge. In many industrial processes, process knowledge is available from interviews with experienced operators. By analyzing experimental process data and investigating the static and/or dynamic characteristics of the plant extra process knowledge can be gained. By incorporating the model-based knowledge into the former heuristic based controller, the overall control performance can be improved. In this study, several human experts (i.e. combine field testers, contractors and engineers) are available who spent time learning how to control the process best. The latter knowledge will be combined with the model based knowledge and control system for reducing combine platform loss will be designed