Instrumented rig for cassava harvesting data acquisition

In the design of a viable and appropriate cassava tuber harvester, the lifting coefficient of cassava tuber was determined to be a function of lifting force, lifting time, speed of lifting, weight of the tuber and soil surrounding the tuber.  This paper described the design, construction and operation of an instrumented rig which allows the simulation of cassava tuber harvesting in the field.  The rig consisted of the gantry, chain block, chains, hook/fisher, variable speed electric motor, 5 kN load cell and DI-1000U data logger.  The developed rig was tested in a matured cassava field located at the experimental farm of the National Centre for Agricultural Mechanization, Ilorin, Nigeria in 2012.  The rig effectively uprooted cassava tuber in the field in about 10 seconds and gave the maximum force of 678 N at soil moisture content of 11.96% db and uprooting speed of 8 mm/s.  The developed rig should be utilized to generate force required to harvest cassava tubers at various soil moisture content and speed of uprooting at various soil types.  The data generated could be utilized as base line data for the development of viable hand held and tractor drawn cassava harvester

Effect of physical and mechanical properties of cassava tubers on the performance of an automated peeling machine

Peeling of cassava tuber at all levels is still largely carried out manually; however, this work is presented with a view to investigate the effect of physical and mechanical properties of cassava tubers on mechanical peeling and hence provides a basis for cassava peeling mechanization. These properties include size of the tuber, tl, proportion by weight of peel, wp, average moisture content of the peel, map, peel thickness, tp, tuber diameter, td, tuber surface taper angle, α, peel penetration force, F, and peel shearing stress, ts. The results showed that for Slmhf; tl ranged from 140-460mm, wp ranged from 13.12-20.06%, map was 76.27%, tp ranged from 1.62-4.34mm, td ranged from 31.08-136.63mm, α ranged from 9.03-23.130, F ranged from 0.17-1.85N/mm, ts ranged from 0.85-9.25N/mm2 and quality performance of the machine, QPE, for this tuber ranged from 70.82-96.21%. Similarly, for Ssmlf; tl ranged from 125-362mm, wp ranged from 10.52-16.66%, map was 70.97%, tp ranged from 1.22-4.12mm, td ranged from 18.86-99.29mm, α ranged from 5.20-12.290, F ranged from 0.13-1.54N/mm, ts ranged from 0.65-7.70N/mm2 and quality performance of the machine, QPE, for this tuber ranged from 67.27-92.25 %. The results confirm influence of physico-mechanical properties of cassava tuber on mechanical peeling