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ThesisItem Open Access Development of low cost electrostatic spray-charging system for liquid formulations(Department of Farm Power Machinery and Energy, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 2016) Dipak Khatawkar, S; KAU; Dhalin, DThe introduction of electrically charged sprays in agricultural application has become inevitable for better control on droplet transference with reduced drift and increase in application efficiency with less spray chemical requirements. In the present study was under taken to develop an electrostatic induction spray charging system as attachment to powered knapsack mist-blower. A high voltage generator was fabricated on the basis of Cockcroft-Walton voltage multiplier principle with input of 6 V DC battery to provide high voltage required at the developed charging electrode assembly (Model III, Model IV and Model V) for inducing electrostatic charge on spray droplets. As the existing (Model I) and redesigned (Model II) nozzle failed to give fine atomization, a self-atomizing hydraulic nozzle was developed for delivering the droplet spectrum required for effective electrostatic charge induction. The three working models (III, IV and V) were evaluated for charge to mass ratio (mC.kg-1) at five electrode potentials (1 kV, 2 kV, 3 kV, 4 kV and 5 kV), four electrode placement positions (0 mm, 5 mm, 10 mm and 15 mm) and five distances (50 cm, 100cm, 150 cm, 200 cm and 250 cm) from the nozzle. Model V with electrode voltage potential at 5 kV and EPP at 5 mm shown the maximum CMR value (1.088 mC.kg-1), followed by Model III (0.888 mC.kg-1) and Model IV (0.777 mC.kg-1) with same combination of variables. In contrast with commercial system (ESS-MBP90) it was observed that except at 50 cm distance from nozzle, Model V (at 4 kV and 5 kV) surpassed commercial system in CMR from 100 cm to 250 cm distance. To avoid air blast injury of plant, the nozzle has to be 100 cm to 150 cm away from the plant. The droplet spectrum of the developed system was analysed and observed that the size of droplets were 100 to 200 μm. The deposition efficiency of the developed system was on par with that commercial unit, and was within the range of 60 to 70 per cent. The developed system found to be cost effective and significantly consistent than the commercial system.ThesisItem Open Access Ergonomic investigations on hand arm vibration of brush cutter for the development of a vibration reducing aid(Department of Farm Power Machinery and Energy, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 2016) Aswathi, K; KAU; Sureshkumar, P KBrush cutters are widely used in Kerala for weeding and clearing fields. While operating brush cutters, certain amount of vibration is transmitted to human body.Extended exposure to mechanical vibration can induce degeneration of the vascular and sensio-neural systems in the hand called hand-arm vibration syndrome (HAVS).The hand-arm vibration syndrome (HAVS) is a complex condition associated with vibration exposure and the use of hand-held vibrating machines. The vibration exposure of worker can be decreased by proper selection and maintenance of tool. To study the ergonomic aspects and hand transmitted vibrations of brush cutters, six subjects (3 male & 3 female) were selected who arehaving experience in operation of brush cutter.A suitable vibration reducing aid for brush cutters is designed and fabricated keeping the view that it should be capable of transmitting at least a part of the vibration produced at cutter head to the ground.It should be easily attached or detached from the brush cutters shaft.The material used for the vibration reduction aid should be light in weight and sturdy, so that it could be raised along with the cutter head by the operator. According to the conceptual design, a vibration reduction aid is developed and field tested. It consists of parts viz. curved arms, fixture to arms, quick fixing locks, ground rollers, rollers fixture and rubber grip. The brush cutter and vibration reducing aid is evaluated in the field with different cutter heads viz. nylon rope, 2 blade, 3 blade and circular blade. The experiment is repeated for 2-stroke and 4-stroke models of brush cutters operated by male and female subjects. The energy expenditure for brush cutter operation is calculated for two models of brush cutter for all subjects and compared. A statistical analysis is conducted using MSTAT software and found that the developed vibration reducing aid, blade and type of internal combustion engine have significant effect on vibration excitation in both right and left handles of brush cutters selected. The proposed method of evaluating occupational risk related to mechanical vibration exposure while working with brush cutter makes it possible to account the effect of attachment, cutter head and type of internal combustion engine. Subjective ratings like ODR, OER, OSR and BPDS also indicated significant effect of reducing vibration due to the vibration reducing aid.ThesisItem Open Access Design analysis of kau pokkali paddy harvester towards the development of its scale down prototype(Department of Farm Machinery and Power Engineering Kelappaji College of Agricultural Engineering and Technology, Tavanur, 2018) Venkata Reddy, H K; KAU; Jayan, P RThe term ‘Pokkali’ used in the common parlor refers to a salt tolerant traditional rice cultivar grown in the coastal saline soils of Kerala, India. The Pokkali field is a unique eco-system prevailing in the coastal tract of Kerala with rich bio diversity and amazing capacity to produce organic rice and shrimp alternatively. Rice is grown during non-saline period and the farmers carry out shrimp culture during the saline phase with both having unique symbiotic benefits. Pokkali areas lie in Trissur, Ernakulum and Alappuzha districts covering a total area of 8500 ha. It spreads over 34 Krishibhavans of these three districts. In the saline, water-logged Pokkali farm lands, rice and shrimps are farmed alternatively. The conventional method of harvesting of Pokkali paddy crop by using sickles. The various farming operations in Pokkali paddy cultivation, the harvesting is done by women labourers by walking on the swampy and marshy inundated paddy fields at waist-deep water, which is laborious, tedious and cumbersome. Though a number of paddy combine harvesters are commercially available, none cannot be used in such marshy water logged areas for harvesting paddy. Hence, a power operated floating harvester with provisions for harvesting and conveying the ear heads (panicles) of submerged paddy was developed at KCAET, Tavanur. The overall size of the harvester is 9.6 x 2.2x 2.2 m with a total weight of about 3 tonnes. Due to the over size and weight, the manoeuvrability become a great problem for transportation and operation in small paddy lands. It necessitated designing a scale down proto type of the harvester to operate in all Pokkali areas for easy transportation and good manoeuvrability. The major functions of a Pokkali paddy harvester are floating in water/moving in puddled soil, cutting and conveying of the panicles. The design analysis of the harvester is sequentially carried out for the floating barge, harvesting unit and hydraulic system. Hydraulic drive system consisted of a hydraulic pump, pressure gauge, valves, filters, etc. to guide and control the system. The capacity of the hydraulic tank was 150 litres and double acting hydraulic pump has 61.0 l min-1. Harvesting unit of the Pokkali paddy harvester consists of a reel, cutter bar and conveyor. Reel delivers the stalks to the cutting mechanism, the cutter bar cuts crop and conveys through front conveyor and transferred to in the central conveyor. Width of the cutter bar was 2.1 m with serrated blade to avoid spilling of the stalks. The vertical centre of gravity of the harvester was designed as 0.854m and longitudinal centre of gravity as 4.58 m. It was found out that the design of the existing KAU Pokkali paddy harvester was perfect considering the buoyancy and stability aspects. The overall size of the newly designed scale down prototype is 6.2 x 1.7 x 1.7 m with a total weight of about 1700 kg. A scale down prototype of the harvester is designed in such a way that to suit for fragmented Pokkali areas. The vertical centre of gravity of the scale down prototype is 0.58 m, longitudinal centre of gravity is 2.67 m and transverse centre of gravity is zero. As the transverse centre of gravity is zero, scale down Pokkali paddy harvester is stable to float and longitudinal centre of gravity lies near to the centre and adjacent to the front and rear side of the harvester, it become a well-balanced machine.ThesisItem Open Access Design and development of artificial pollinizer for pollinating tropical vegetables under protected cultivation(Department of Farm Machinery and Power Engineering Kelappaji College of Agricultural Engineering and Technology, Tavanur, 2018) Ramya, R; KAU; Sureshkumar, P KArtificial pollination is a process that is highly require in vegetable crops grown under protected cultivation since, protected environment offers barriers to natural agents for pollination such as insects, wind or water. A study was undertaken to design and develop an artificial pollinizer for pollinating tropical vegetable crops under protected cultivation. To obtain preliminary data required for the design, floral and physical characteristics of flower, anther and pollen of selected tropical vegetable crops were studied in laboratory conditions. Accordingly a conceptual design was evolved and two models of artificial pollinizers were developed. Suitability of the developed pollinizer was evaluated in laboratory as well as field conditions. Results of the evaluation have been presented and analyzed. Six tropical vegetable crops were selected for the preliminary studies like floral characteristics, physical and dimensional measurements of flowers, anther and pollen grains were conducted in the laboratory. Sizes of pollen grains were measured by using Olympus Bx43 light microscope and the measurements were taken using the software Ultrascope version 9.1. Shape was determined from standard shape charts suggested by UPOV, 2007. The shape of pollen grains of tomato, pumpkin and ash guard are found to be „circular‟ with a Length/Width ratio ranging from 1: 1 to 1: 1.1. Pollen grain of chilli is „broad deltate‟ with L/W ratio of 1: 1.2. Pollen grains of water melon and cucumber are „narrow oblate‟ with a L/W ratio of 1: 1.13 to 1:1.15. Based on the preliminary studies, functional requirements and conceptual designs two models of the artificial pollinizers were designed and developed. Artificial pollinizer Model – I uses air as the medium for collection of pollen from flowers. Suction pressure developed by a vacuum pump suck the pollen grains from the male flower to a pollen collection chamber. The pollen collection unit is provided with a brush tip which detach the pollen grains from the flower and sucked by a vacuum pump are deposited in a pollen collection chamber. A screen mesh filter of 15 μm aperture is used in the chamber to prevent the pollen grains from carry away. Components of artificial pollinizer model – I includes pollen collection unit, pollen collection tube, adaptor for pollen collection chamber, pollen collection chamber, air tube, air tube adaptor, a connector and a vacuum pump. An electric powered air blower of 220 V, 50 Hz and 0.55kW is used as vacuum pump. The blower produces a suction velocity of 20-22 ms-1 at 13,000 rpm. Artificial pollinizer Model – II uses water as the medium for collection of pollen from male flowers. Water is sprayed from a nozzle to the male flower kept carefully in a pollen collection chamber. Water spray produced by a pneumatic hand pump from the nozzle wash out the pollen grains from the flower and is collected in the water tight container. Components of artificial pollinizer Model – II includes a spray nozzle, pneumatic hand sprayer, water container and pollen collecting chamber. Collected pollen can be sucked by a syringe for spraying to the female flower for artificial pollination. Dry pollen collected by Model – I is also mixed with water and used for artificial pollination using a syringe. Evaluation of artificial pollinizer was done by accessing pollen viability and fruit set efficiency. Viability of pollen was observed under laboratory condition and fruit set efficiency was observed under field conditions. From the studies it is observed that, pollen viability is decreasing with increase in storage period for both the crops. Maximum pollen viability is observed when artificial pollination was done with fresh pollen grains. Also, the viability is found higher for pollen stored in 1 % sucrose solution than pollens stored in plain water in both crops. Study on fruit set efficiency is also seems to be decreasing with increase in storage period for both the crops. Maximum fruit set efficiency is observed when artificial pollination was done with fresh pollen grains. Fruit set efficiency is higher for pollen stored in 1 % sucrose solution than pollens stored in plain water in both crops. Also the fruit set efficiency values are on par with manual pollination. Stages of fruit development in cucumber and watermelon crops are also observed on the 3 rd, 7th and 15th days after artificial pollination and found that the artificial pollination done using the artificial pollinizer was successful.ThesisItem Open Access Computer aided analysis of 'sit and stand' type coconut climbers for mechanical stability(Department of Farm Machinery and Power Engineering Kelappaji College of Agricultural Engineering and Technology, Tavanur, 2018) Pooja, V; KAU; Jayan, P RCoconuts are harvested by climbing the palm and cutting the nuts down by hand. Manually climbing up and down the palm is hazardous and tedious. Now a days a few models of mechanical coconut palm climbers are available to overcome these drawbacks. Testing the mechanical strength and stability of the coconut palm climbers is necessary to ensure its safe performance under working condition. Among these types, KAU and Farmer’s models were selected and its three dimensional models were generated in Solidworks 13.0 software. The static and fatigue analysis of these selected models were carried out in the ANSYS 15.0 software. The assembly of each component of the top and bottom frames of the models were created and saved in step file format. The file was then imported to the ANSYS 15.0 software for the static and fatigue analysis. Preprocessing steps such as meshing, selection of material and application of boundary conditions were then carried out sequentially to establish static and fatigue problems. In the KAU model top and bottom frames were steel and aluminium materials, wherein the Farmer’s model top and bottom frame were made of structural steel. The boundary conditions imposed are the application of loads and fixing of supports. Various loads of 400, 500, 600, 700, 800, 900 and 1000 N were applied and under each load the analysis was carried out. In the KAU model, the inner face of the bent tube and V tube and in the Farmer’s model, the rope and curve plate were considered as fixed supports. The static analysis interpreted were the equivalent (Von-Mises) stress, equivalent elastic strain and total deformation while fatigue analysis interpreted the fatigue life and factor of safety. The results showed that as the load increased the Von Mises stress was found increased. Also, there were decreasing trends for the factor of safety and fatigue life. The top frame of KAU models have factor of safety more than three, two and one up to 400, 500 and 1000 N load respectively. The infinite fatigue life cycles were observed up to 800 N. The bottom frame of KAU model have factor of safety more than one up to a load of 1000 N and have infinite fatigue life cycles up to 1000 N load. Hence KAU model is safe to operate up to a load of 1000 N. The top and bottom frames of the Farmer’s model also found out the factor of safety more than one and have infinite fatigue life cycles up to load of 1000 N. Hence Farmer’s model is safe to use up to a load of 1000 N. further changes in material, design or dimensions are suggested to get more factor of safety for loads from 700 to 1000 N for both the selected models. As there is no specified test codes available for manually operated mechanical tree climbers, a draft test code with Minimum Performance Standard (MPS) was also prepared under this study.ThesisItem Open Access Investigations on the adaptability of wireless sensor networks (WSN) based technology for harvesting crops(College of Agricultural Engineering and Technology, Kelappaji, 2016) Ayisha, Mangat; KAU; Shivaji, K PHarvesting has been identified as one of the critical and resource consuming operation because of several reasons especially inside polyhouse structures. Knowledge of physical properties of crops and fruits like cucumber plays an important role in the design and optimization of its machinery. Evaluation of these properties like plant height, leaf numbers, leaf length, leaf width, fruit length and width were taken for observation. It was seen that, these properties had a direct impact on deciding the components of the harvester. Plant height determined the height of the harvester; leaf parameters decided the obstacle parameters in the work space. Fruit holding capacity of the cutting unit was depended on fruit parameters. By analyzing all these data and the past work in the field of robotics, a preliminary model of a harvester was fabricated. Out of the harvesters developed so far in the field of agriculture, the most simple and economical method was selected for this study. The principle of linear actuators was adapted for the design of the harvester by incorporating screw rods and DC motors. The basic components for the harvester were identified with three Degrees of Freedom. The moving unit with wheels contributes to the motion in X direction. The vertical screw thread makes the movement in Y direction and the horizontal unit gives the motion in Z direction. By studying the biometric properties of plants and crops, the height of the harvester was confined to 2 m, width of horizontal unit as 45 cm and the base platform with 45X45 cm. A control board was used for controlling the motors which causes motion for the threaded rods. Accordingly, a laboratory model was fabricated and its functionality was tested. It was found working successfully in the laboratory conditions. The current trend in high-tech agriculture is towards switching from a manual system to automatic operations. Hence, the present study is a promising technology that can be converted to a fully automatic machine with future developments.
