Development of a mobile device for coffee harvesting suitable for the Colombian conditions

A coffee harvesting system designed specifically for accommodating the treacherous terrains of the coffee plantations in Colombia has been designed and built. A formal design methodology was employed that assisted in the identification and assessment of unique technical requirements as well as alternative design options.; The harvesting system developed comprises two interacting machines, a Winch moving perpendicularly in the top of the plantation, and a Harvester moving uphill, or downhill, shaking the foliage of the trees. The up and down movement of the harvester is controlled by the winch. The harvester has an inverted “U” gantry that passes over the coffee trees as the machine moves up and down the slope. Each leg of the gantry can independently pivot about the center of a chassis section, thus allowing the gantry to remain vertical on uneven, steeply sloped terrain while allowing both chassis sections to maintain wheel contact with the ground. An actively controlled hydraulic system is used to maintain the gantry in a vertical orientation.; The system was developed to match plantations with aisles separated 2.0 m between trunks, running parallel to the terrain slope, and for terrain inclinations up to 75%.; The mechanical coffee harvesting system proposed should minimize erosion because the cable-pulled harvester does not require tractive power to be delivered by its wheels. The system also provides the advantage of good position control in the plantation since there is no slip between tires and ground. In order to minimize soil compaction effects flotation tires are used on the harvester.; To control the verticality of the gantry when working, a hydro-electro-mechanical leveling control was designed and incorporated in the machine. This design also followed a structured design methodology that included the development of a detailed computer model to predict performance.; The system has two power supplies, one in the harvester and one in the winch. The first source provides power to its hydraulic mechanisms. The power provided to the winch is to pull the harvester uphill and to move itself from station to station. The machine will be undergoing lab and field testing in Colombia.