Multiple Attributed Parametric Review Study on Mechanical Cotton (Gossypium hirsutum L.) Harvesters

Crop characteristics of cotton are crucial to identify the important crop attributes like plant height, canopy width, sympods and monopods distribution, row spacing which affects the performance of mechanical harvesters. The activity and effectiveness of most harvest aids, including desiccants is reduced by low temperature conditions. Trash content was observed to be lesser in cotton harvested by cotton picker than cotton harvested by cotton stripper. It was found that a maximum cotton yield of 1000 kg acre-1 was obtained for a cotton plant population ranging between 45,000 and 90,000 plants acre-1. Likewise, a minimum of 700 to 740 kg acre-1 was observed for a cotton plant population of 33,000 plants acre-1. In higher yielding cotton, cotton pickers recorded higher picking rate than cotton strippers. Picking/harvesting efficiency of cotton stripper with both finger and brush type mechanism was higher than the spindle type cotton picker. Picking efficiency of pneumatic picker was higher than the other types of picking mechanisms, but with lesser rate of picking capacity. Gin turnout of cotton was higher with cotton picker when compared with cotton stripper due to lesser trash content in picker harvested cotton. The horsepower requirement of cotton stripper ranged from ½ to ¼ horsepower and cost is about two-thirds of the price as compared with cotton picker. The scheduling and monitoring of various activities involved in cotton picking by using a suitable software model can increase the benefits of both growers and harvesting companies. The reduction in uniformity with roller gin-type lint cleaners ranged between 0.2 to 0.8%, which was lesser as compared with saw-type lint cleaners. Introducing mechanical harvesting has always been a decades-long process. In Turkey, it took 20 years and in Greece, this process took place very gradually over a 15-year period. Top cotton producing countries like India, Pakistan, China, Uzbekistan and other developing countries like Iran Paraguay are still not using machine harvesting. The introduction of mechanical cotton picker or stripper can help improve quality and quantity of cotton picking thereby giving more benefit to growers in developing countries and improving their socio-economic status. The most controversial issue raised by the introduction of the mechanical cotton harvester is great migration as the machines eliminated jobs and forced poor families to leave their homes and farms in search for urban jobs. Therefore Government policies towards cotton harvesting mechanization must include the alternative jobs, packages for dependent manual cotton pickers and their families.

VERTICAL SPINDLE COTTON HARVESTER WITH SYMMETRIC MOVEMENT OF SPINDLE DRUMS

The article deals with the trends in the development of structures, research work on modernization and creation of new vertical spindle cotton harvesting apparatus (CHA). Authors developed new CHA that works as follows: the CHA with a cotton picker moves on the cotton field; the cotton plants getting into the inter-drum slots are processed, that is, the raw cotton be harvested. The CHA are in their original position before picking raw cotton. When a thick cotton plant gets into the inter-drum slot of the front pair of drums, the spindle drums move apart and the inter-drum slot opens, while the connecting rods and the sliders move forward, providing the symmetrical opening of the slot relative to the longitudinal line of the cotton plant row. Further, this thick plant falls into the inter-drum slot of the second pair of drums, while the inter-drum slot of the second drums opens, while the connecting rods and the sliders move along the guides forward, providing the symmetrical opening of the slot relative to the longitudinal line of the cotton plant rows. With such a pairwise symmetric movement of the SD, depending on the thickness of the cotton plant, the force of spindle pressing on the cotton plant from both sides is identical and symmetrical, since the SD move symmetrically to the longitudinal line passing along the cotton plant row.

Integrated Optimization of Structure and Control Parameters for the Height Control System of a Vertical Spindle Cotton Picker

Vertical picking method is a predominate method used to harvest cotton crop. However, a vertical picking method may cause spindle bending of the cotton picker if spindles collide with stones on the cotton field. Thus, how to realize a precise height control of the cotton picker is a crucial issue to be solved. The objective of this study is to design a height control system to avoid the collision. To design it, the mathematical models are established first. Then a multi-objective optimization model represented by structure parameters and control parameters is proposed to take the pressure of chamber without piston, response time and displacement error of the height control system as the optimization objectives. An integrated optimization approach that combines optimization via simulation, particle swarm optimization and simulated annealing is proposed to solve the model. Simulation and experimental test results show that the proposed integrated optimization approach can not only reduce the pressure of chamber without piston, but also decrease the response time and displacement error of the height control system.

Analysis of the shift quality of a hydrostatic power split continuously variable cotton picker

In order to improve the ride comfort of a continuously variable cotton picker, the shift quality of the cotton picker is analysed. Firstly, the transmission principle of the hydrostatic power split continuously variable transmission (CVT) with a single planetary gear set is introduced; secondly, the shift dynamic model of the power train is constructed, and the key models are verified by experiments; finally, the influence law and mechanism of various factors in the shift qualities of a cotton picker are analysed. The results show that the increase in main circuit pressure will reduce the shift quality of the cotton picker; the influence of clutch-charging flow and acceleration rate on the shift quality of the cotton picker can be ignored; with the action time of the clutch delayed in a certain range, the shift impact first decreases slightly, then increases, and finally decreases; the increase in the cotton box weight can slightly improve the shift quality of the cotton picker but is at the cost of consuming more clutch-sliding energy. If different factors are evaluated together, the value of the main circuit pressure and charging flow should not be too large or too small. At the same time, the action time of a clutch to be disengaged should be delayed, and the action time of a clutch to be engaged should be advanced. The conclusions of this study can provide theoretical support for the controller development of a continuously variable cotton picker.

POSSIBILITY TO ENSURE THE TECHNICAL EFFICIENCY OF THE VERTICAL SPINDLE COTTON PICKER

In order for the use of the vertical-spindle cotton picker, created in Uzbekistan, to be economically effective, it is necessary, first of all, to increase its completeness of harvest. This indicator depends on many factors. However, the most important factor is that the spindle friction drive function is inadequate. Friction forces between the friction drive belts and the spindle roller determine its tagging capacity. The magnitude of the friction force depends on the pressure of the belts on the roller, which in turn depends on the tension of the drive belts. The article analyzes how much the tension of the drive belts in economic conditions meets the requirements.Key words:completeness of cotton picking by the apparatus; friction drive; belt tension; traction ability; direction and magnitude of the absolute speed of the spindle tooth; moment of power; variability of the angular speed of the spindle; gripping power of the tooth