Harvesting Task Research Articles

Design of an Agricultural Robot for Harvesting Melons

The performance of an agricultural robot has been evaluated through simulation to determine design parameters for a robotic melon harvester. Animated, visual simulation provided a powerful tool to initiate the evaluation of alternative designs. To quantify the many, closely-related design parameters, numerical simulation tools were developed and applied. Simulations using measured cantaloupe locations revealed the effect of design parameters (configuration, number of arms, and actuator speeds) on the average cycle time. Simulation results predicted that a Cartesian robot would perform faster than a cylindrical robot for the melon harvesting task. Activating two arms in tandem was the fastest configuration evaluated. Additional sets of melon locations were stochastically generated from distributions of the field data to determine performance for planting distances between 25 and 125 cm. The fastest cycle time was achieved for an experimental cultural practice that consisted of one plant on each half row in an alternating sequence with 125 cm planting distance. The performance of the robotic melon harvester was found to be highly dependent on the picking time, actuator speeds and planting distance.

An algorithm defining the motions of a citrus picking robot

A computationally efficient algorithm for determining the motion sequence of a citrus picking robot that allows the picking time to be minimized was developed. The suggested algorithm can be applied in real-time. The sequence of motions was obtained from the solution of the travelling salesman problem (TSP) using the total distance travelled along near-minimum-time paths between all fruit locations as the cost function to be minimized. This cost function takes into consideration both the inertial properties and kinematic structure of the robot manipulator. Simulation results for a cylindrical type of robot for twenty measured citrus trees indicate that the mode of travel through the tree is influenced by the geometric shape of the tree. The optimal path between consecutive fruit locations depends on the inertial parameters of the robot. Dividing the tree into subvolumes reduces the computation time required by the algorithm. Travelling vertically through the tree's subvolumes reduces the picking time as compared to horizontal travel. The suggested algorithm can serve as a basis for comparing the performance of different robots and can help in selecting the most efficient robot design for any given harvesting task.

Harvesting whole trees with processing and log allocation (in the forest) to conventional and energy products

Conventional harvesting operations currently collect large quantities of biomass used for energy generation in the form of hog fuel and black liquor produced as by-products at sawmills and pulpmills. An increase in this quantity will be obtained from integrated systems when components of existing harvesting tasks are improved, in particular delimbing by processing trees in bulk. Methods to improve profitability by the optimum allocation of the various portions of a tree to the different products, including energy wood, are being successfully implemented through the use of computer-based bucking algorithms.

Physiological demands of forest harvesting tasks: A case study of skidding operations

In spite of increased mechanisation, forest harvesting tasks continue to place moderate to heavy physiological demands on employees. A work-heart-rate study of skidder operators in the southern United States during summer months is reported. The study illustrates how data may be obtained without interference with production and the uses of the data for documenting task difficulty and evaluating different work methods. The potential use of work physiology data for harvesting worker selection is indicated although the study data were not entirely successful on this point.

Heart-rate response to forest harvesting work in the south-eastern United States during summer.

Abstract The physiological workload of forest harvesting workers during summer in the south-eastern United States was evaluated by measuring work heart-rate response. The harvesting tasks considered were chainsaw felling, cable skidding, bucking and trimming at the landing, knuckle-boom loader operation, feller-buncher operation and grapple skidding. VO2 max of the workers ranged from 28 to 53 ml min−1kg−1. The WBGT ranged from 20 to 344°C during data collection. The task time-weighed, age-corrected, percent maximum heart-rate response ranged from 42-5 to 69 2°. The data indicate that the manual and semi-mechanized tasks are potentially stressful and that hotter environmental conditions increase the likelihood of higher heart-rate responses. No relationship was found between heart-rate response and three measures of static muscle strength.

Control Químico de malezas en maní (Arachis hipogaea L.) en la Provincia de Córdoba

The Province of Cordoba represents approximately 90% of the area planted with peanuts in Argentina. Among the multiple factors that affect crop productivity, weeds occupy a preponderant place because, as is known, not only compete for water, light, nutrients and space, but also hinder the tasks of harvesting.