Fruit harvesting continuum manipulator inspired by elephant trunk

By combining the investigation of the biomechanics and behavior of elephant trunk in the performance of a wide range of dexterous manipulations,a novel approach in the design and kinematics modeling of a fruit harvesting continuum manipulator was proposed.By comparing the structure of two different species of elephant trunk,a new continuum structure which matched the key features of elephant trunk was designed.Based on analysis of the underlying elephant trunk’s grasping mode,a novel kinematics model was proposed.Contrast to traditional robot kinematics which focused on end effector’s position and posture,the proposed continuum manipulator kinematics focus on the center of manipulator’s position and posture,which is more effective when trunk robot realizing grasp and establishes the foundation for its application.Finally,three typical grasping experiments were implemented.The experiment results showed that the manipulator could conduct wrap/pinch manipulations effectively for both small objects and bigger ones.

Model Design and Development of a Telescopic Palm Fruit Harvester

This research paper presents a comprehensive conceptual design approach for the development of a telescopic machine system, which is portable and will provide a safe method of harvesting palm fruits. For this machine system development, the material for each component of the machine system was first selected, the boom length, maximum boom angle, force and stroke length of each hydraulic cylinder, the hydraulic pump pressure, base weight, permissible weight of the cutting system and power required were then calculated in the design analysis. Furthermore, from the calculated parameters, the model of the system was created using SolidWorks engineering software, the model was developed and tested. The result shows that the cutting time of the system for one bunch of palm fruit was longer when compared to conventional systems. It was concluded that though the machine is maintenance friendly and portable, further improvements in its design are necessary so as to develop a system that will give desirable economic output at a shorter time.

Thinning effects on walnut stem and crown diameter growth and fruiting in the walnut-fruit forests of Kyrgyzstan

The walnut-fruit forests （Juglans regia L.） in southern Kyrgyzstan are considered to be biodiversity hotspots and of considerable economic and ecological importance to local populations. The fruiting ability and stability of these forests are, however, decreasing because of infrequent silvicultural interventions and non-existent natural regeneration. Continuous inventories and walnut harvest measurements were carded out on 18 trial and control plots over the course of i3 year. Results showed that i） thinning had a positive influence on diameter at breast height （dbh） increase, ii） dbh growth and crown area increases are strongly and positively correlated, iii） large crowns enhanced the production of fruits, and iv） temperature conditions had a major influence on the production of fruits. The above-mentioned points are particularly relevant for young plantations but are also valid for relatively old plantations （〉 50 years）. We conclude that regular thinning substantially improves diameter growth, fruit production and ability of trees to withstand wind and snow damage in both young stands and in older walnut-fruit forests.

Development of Autonomous Travelling Device for Oil Palm FFB （Fresh Fruit Bunches） Harvester

Robot technology is a very promising technology for agricultural sector, but the existing industrial robot could not deliver the above-mentioned criteria. Industrial robot mainly uses high voltage electrical power, which is not available at field and outdoor operation. The only available and reliable power is a hydraulic from the tractor. The harvester robot consumes the hydraulic power from the tractor and at the same time the tractor can be used as a traveling device for the robot. This paper describes the study on the development of autonomous tractor for the oil palm harvester. The development took considerations on the design of the electro-hydraulic system and the control software for the robot structure to be flexible enough to operate in plantation environment.

Effects of maturity of citrus fruits on their stalks cutting force

When the citrus harvesting robot harvests citruses,the mechanical properties of citrus stalks have an important influence on the success rate of the citrus harvesting robot.During the harvesting,the maturity of citrus fruits not only determined the harvesting time of citrus fruits but also affected the mechanical properties of citrus fruit stalks.In this study,the changes in the cutting force of citrus fruit stalks were described during the maturity of citrus fruits,and the effect of the maturity on the cutting force of stalks was clarified,so as to determine the harvesting time with the minimum cutting force required for harvesting citrus fruits by the harvesting robot.During the maturity,the relevant parameters of fruit maturity,such as the hardness,pH,and solid solution content of citrus fruits,were monitored.The results showed that there is a significant correlation between the hardness,pH,the solid solution content of citrus fruits,and the cutting force of citrus fruit stalks during maturity.The single-factor mechanical model of hardness,pH,solid solution content of citrus fruits,and the cutting force of citrus fruit stalks were established based on the data of 2019,which were verified through tests in 2020.The test results are as follows:during the ripening period of citrus fruits,the fruit hardness varies in the range of 0.13-0.31 MPa,the hardness changes by 0.02 MPa,and the cutting force changes by about 2.0-6.0 N;the pH of the citrus fruits changes in the range of 2.8-4.0,and the cutting force changes by about 1.5-2.2 N for every 0.1 change in the pH;the variation range of fruit solid solution content is 6.5%-9.0%,and for every 0.2%change in solid solution,the cutting force of citrus fruit stalks changes by about 1.25-2.0 N.The mechanical models can predict the cutting force required to cut off citrus fruit stalks according to the relevant parameters of citrus fruit maturity and can provide a reference for effectively evaluating the required cutting force.