The Development of a Harvesting Machine for Passion Fruits

Transcription

1 Proceedings of the 4 th International Symposium on Machinery and Mechatronics for Agriculture and Biosystems Engineering (ISMAB) May 2008, Taichung, Taiwan The Development of a Harvesting Machine for Passion Fruits Feng Ou-Yang 1*,Pei-Chia Hsieh 2, Yi-Chich Chiu 3 Biomechatronic Engineering, National ILan University, Taiwan * yfou@ niu.edu.tw Abstract: After June mature passion fruits begin to fall on the ground from the shelf every afternoon in Taiwan. The farmers have to bend over to pick up the mature fruits from the ground and collect in the buckets. The main purpose of this research is to develop a passion fruits harvesting machine to improve the efficiency of manual harvesting. A pick-up machine has been developed. It has the functions of picking up fruits and moving in the field. It consists of rotary brushes, an auxiliary plowing plate, conveyor chain unit and a collecting box. The field experiments of harvesting efficiency and damage have been done and investigated to improve the functions of the machine. The result of the experiments shows that the machine can enhance the speed of harvesting and relief the labor-intensive work. Key Words: Passion fruits, Harvesting Machine, Pick up INTRODUCTION The planted area of passion fruits is about 327 Hectare and the annual production is 5700 tones approximately in Taiwan based on the 2006 Agricultural Statistics Yearbook. More than 70% of the planted area is located in Puli, Nantou in Taiwan. The climate and environment of Puli are very suitable for the cultivation of the passion fruits. The harvesting time of the passion fruits is from June to December. After June some passion fruits begin to get ripen and their surface color turns to brown from green. The mature fruit will fall on the ground from the shelf every afternoon. The farmers have to bend over to pick up the fruits from the ground and collecting in the buckets. The fruits remain on the shelf are green, more sour, less flavor and not suitable to harvest. Farms in Taiwan do not pull passion fruits directly off the shelf. Wu (1998) has designed a passion fruit collection system using several slanted devices. Those collecting devices were setup under the shelves. Once mature fruits fall on those devices, they will roll down on the slanted devices to a collecting box at the end. This system takes larger space. If other machinery managements are needed, the farmers have to remove the system and install back again. Also the surfaces of fruits easily get scratched during rolling and collecting process. PM-51 The authors are solely responsible for the content of this technical presentation. The technical presentation does not necessarily reflect the official position of Chinese Institute of Agricultural Machinery, Taiwan (CIAM), and its printing and distribution does not constitute an endorsement of views which may be expressed. Technical presentations are not subject to the formal peer review process by CIAM editorial committees; therefore, they are not to be presented as refereed publications. Citation of this work should state that it is from the 4 th ISMAB paper. EXAMPLE: Author's Last Name, Initials Title of Presentation. The 4 th ISMAB May 27-29, Taichung, Taiwan. For information about securing permission to reprint or reproduce a technical presentation, please contact CIAM at mailto:choucy@ntu.edu.tw or Chinese Institute of Agricultural Machinery, 136 Chou-Shan Rd., Taipei 106, Taiwan.

2 A citrus fruit pick-up machine was developed by OXBO (Ganesh et. al, 2006). Two long-arms sweepers installed in front are used to sweep oranges. Cutters cut branches that are between the trees. The pick-up head assembly uses lollipop-type fingers to pick up the oranges from the ground. Strippers then strip the oranges from the pick-up wheel into a conveyor. The picking efficiency was about 97 percent on the ridges and it was as low as 80 percent on the swale. Brown (2002) discussed different harvesting system for citrus. A mechanical fruit pick up system use turning brushes to collect citrus, and use cylinder rack to pick up citrus and send to container. The cylinder rack is not suitable for passion fruits, because it may damage the surfaces of fruits. A harvesting system was developed to determine the feasibility of mechanically harvesting fresh market quality eastern thornless blackberries by Peterson and Takeda (2003). An over-the-row harvester utilized a direct-drive spiked-drum shaker for selective fruit removal and an energy absorbing catching conveyor to collect the berries. The current harvesting method of the passion fruit in Taiwan is to pick up the fruits from the ground and collecting them in the buckets by farmers. This is quite time-consuming and cost-consuming. Long hours of bending over also induce waist injuries of farmers easily. The main purpose of this research is to develop a passion fruits harvesting system to improve the efficiency of the labor-intensive work during harvesting and solve the problem of labor shortage for harvesting. MATERIALS AND METHODS INVESTIGATION OF THE PLANTING ENVIRONMENT OF PASSION FRUITS In order to design a suitable harvesting machine for the domestic passion fruits in Taiwan, the planting environment and its harvesting method were investigated. The following data were collected: the physical properties of the fruits, the density of distribution of fruits on the ground, the distances between two crops, the height of the shelf, the conditions of the ground in the orchid field, etc. DESIGN METHODS OF THE HARVESTING MACHINE This machine consist of the followings parts (Fig. 1(a)): the rotary brushes, the auxiliary plowing plate, the conveying chain unit, collection boxes and the power system. The width of the harvesting machine is designed about half the width of the distance between two crops. The fruits in each row will take harvesting machine to run twice to pick up. Fruits on the ground are first gathered and picked up by three rotary brushes. Two brushes on left and right sides of the machine are designed to gather fruits together to the middle of the main brush in the center to ensure that the main brush can sweep in fruits more effectively. The fruits will be swept in on the plowing plate and waited to be picked up later. Two brushes on each side are designed to be able to adjust their position to follow the fluctuating surface in the field by using two bevel gears. Those two brushes could increase the harvesting width of the machine without increase the size of the machine. However, the mobility of the machine will be PM-52

3 limited when changing rows at the end of each row. Therefore, they are also designed to be able to be folded up quickly when needed (Fig. 1(b)). The auxiliary plowing plate is designed to let the central brush sweep in fruits successfully. Because the surface on the ground of the field is not even, the plate might rub with ground and cause large friction while moving. Because most of farmers use other machines for agricultural management, those machines might cause deep ditches on the ground. If fruits drop in ditches, they are trapped and hard to be swept in. Therefore, the plowing plate (Fig. 2(a)) is designed to be able to float up and down to follow the variation of the ground. This floating plate under the main fruit-collecting brush is designed like piano keys (Fig. 2(b)) which can always keep their position close to the ground by gravity. The vertical displacement is determined by the location of the two end positions. This design can overcome the problem caused by the undulating surface in the field. The fruits are picked up by the brush and the plastic plates installed on the conveyor chain unit from the auxiliary plow plate. The stones and weeds will drop out to the clearance between plates and separate from fruits in the conveyor. A collecting box is designed to collect fruits from the conveyor. When the box is full, two doors at each side can be opened to unload the fruit out. For the efficiency of the harvesting, the machine is powered by a gasoline engine. Engine power is first send to main transmission part and then divided into two parts. One is for the power of machine wheels which are controlled by two clutches, and another is for the harvesting including brushes and the conveyor. (a) (b) Figure 1. The designed harvesting system for passion fruits when brushes are (a) unfolded; (b) folded. (a) (b) Figure 2. Two designs of the auxiliary plowing plate (a) floated plate; (b) piano keys PM-53

4 FIELD EXPERIMENTS The field experiments of the passion fruit harvesting machine were done in Puli, Nantou. 25 fruits were randomly distributed in the area of 10 m x 1.4 m in the field. The density of fruit is nearly 1.92 fruits per meter square. Repeat the field experiments at different speeds of engine and find out the most suitable speed of engine for harvesting. Also compare the efficiencies between manual harvesting and machine harvesting. The surface damage of passion fruits will degrade their quality and also their price. The shelf life of the fruits will also be shortening if they are damaged. Randomly picked 25 fruits harvested by machine each time from the colleting box to observe their damages or scratches on the surface. RESULTS AND DISCUSSION THE PLANTING ENVIRONMENT OF PASSION FRUITS We have already investigated planting environments of Puli and Taitung. The planting and management methods in Puli are comparatively mechanized, and the field environment is much better for machines, too. The management method in Taitung is not so delicate and the field is covered with lots of stone and weeds. The height of the shelf was about 180cm in the orchard and the width of each row is about 240 cm in Puli. The ground is fairly flat which is suitable for mechanized management such as mover. The different conditions of planting environment between Puli and Taitung are listed in Table 1. The new type of planting environment in Puli is very suitable for machinery harvesting. Table 1. Planting environments for passion fruits Puli Taitung New type Old type Shelf height 190 cm 190 cm 210 cm Interval distance between trees 130 cm 130 cm 333 cm Interval distance between ridges Ridge height Ridge Width cm cm 511 cm ground is flat and no apparent ridge ground is flat and no apparent ridge 28 cm 108 cm Surface conditions less stones and weeds less stones and weeds stones, weeds and ditches HARVESTING MACHINE FOR PASSION FRUITS A harvesting machine for passion has been developed (Fig. 3(a)). It was equipped with a 6 hp gasoline engine. The power of wheels, brushed and conveyor can be controlled separately. The width of the main brush for sweeping fruits is 29 cm. Unfolding brushes on two sides of machine can extend its PM-54

5 harvesting width up to 120 cm. Two side brushes can be folded up or take off quickly (Fig.3 (b)). The vertical displacement of the auxiliary plowing plate is about 3cm. The plate is composed by 7 smaller plates designed like piano keys which can also change their vertical position up to 3cm. This design can pick up fruits trapped in the ditch on the ground. (a) (b) Figure 3. The developed harvesting machine when brushes were (a) unfolded (b) folded FIELD EXPERIMENTS OF HARVESTING EFFICIENCY The field experiments of the harvesting machine were operated at the speed of 0.36 m/s. The results showed that 76% of the fruits were picked up and collected in the box successfully. About 13% of the fruits were picked up but fallen from the conveyor because of the vibration of the machine. About 11% of the fruits could not be picked up. Most of those are either too small or trapped in ditches on the ground. The rotational speeds of conveyor and brush were set to 46 rpm and 52 rpm, respectively. FIELD EXPERIMENTS OF HARVESTING DAMAGE About 89% of the fruits were picked up successfully without any damages on the surface (Fig. 4(a)). About 11% of them were damaged. There were two kinds of damages. Some were scratched lightly caused by the collision with plow or other fruits (Fig. 4(b)). Others were damaged severely caused by falling into the gap between plowing plate and conveyor (Fig. 4(c)). (a) (b) (c) Figure 4. The surface of Passion fruits after harvesting (a) Intact; (b) scratched; (c) damaged PM-55

6 CONCLUSION This research has already developed a passion fruit harvesting machine which is powered by gasoline engine. This machine is able to pick up fruits from the ground and collected together in the box. The field experiments showed that the successful harvesting efficiency could reach about 76%, and the damaged rate can be below 11% at the moving speed of 0.36 m/s. At this harvesting speed, each hectare takes only 1.2 hours to pick up fruits. Manual harvesting will take 20 hours for one person to pick up one hectare. Therefore, this harvesting machine can enhance the speed of passion fruits harvesting and relief the labor-intensive work. The successful harvesting efficiency can be further increased by adjusting the angle of the conveyor or add a cover on the conveyor to keep fruits from dropping on the conveyor. The damage rate can also be decreased by increase the speed of conveyor to avoid blocking between plowing plate and conveyor. Other softer material for plates on the brushes and conveyor might also reduce the chances of damages. The collecting box was suggested by farmers to be able to fit the size of their boxes, so that they can just unload the whole box each time when it is full. This could reduce the chance of damage when dumping fruits off the collecting box. ACKNOLEDGEMENTS The authors acknowledge the financial support to this project from Agriculture and Food Agency, Council of Agriculture, Executive Yuan, Taiwan.. REFERENCES Brown, G. K Mechanical harvesting systems for the Florida citrus juice industry. ASAE Paper No St., Joseph, MI: ASAE. D. L. Peterson, F. Takeda Feasibility of mechanically harvesting fresh market quality eastern thornless blackberry. Applied Engineering in Agriculture 19(1): Ganesh, C. Bora, M. Reza Ehsani, Renee Goodrich, George Michaels Field evaluation of a citrus fruit pick-up machine. ASABE, July Taiwan Agricultural Statistics Yearbook Agriculture and Food Agency, Council of Agriculture, Executive Yuan. Nan-Tou, Taiwan. Wu, K. H The harvesing method and device for the passion fruits. The Patent Bulletin of R.O.C. No PM-56