Design, Fabrication and Testing of a Cutting Force Measuring System for Agricultural Stems

Abstract

Stem plants play important roles in agricultural production, and efficient stem cutting is essential for operations such as propagation, harvesting, and biomass processing. However, limited information is available on the cutting-force requirements of agricultural stems and the extent to which stem physical properties and machine operating parameters influence these forces. To address this gap, a cutting-force measuring system for agricultural stems was designed, fabricated, and evaluated. The developed system comprises a cutting unit, a transmission unit, crank mechanisms for motion conversion, a sensor-based instrumentation and data-acquisition system, a prime mover, and a supporting frame. Evaluation indicated that the system was suitable for the intended cutting-force measurement applications. The machine was tested in four replicates using elephant grass (Pennisetum purpureum), stubborn grass (Eleusine indica), wire weed (Sida acuta), Siam weed (Chromolaena odorata), sugarcane (Saccharum officinarum), and cassava (Manihot esculenta). Cassava required the highest cutting force (654.91 N), whereas stubborn grass required the lowest (11.81 N), at moisture contents ranging from 18.3% to 39.0%. The developed system may support students, researchers, and professionals involved in designing agricultural mechanisation equipment for planting, harvesting, and processing operations. Further studies should investigate the effects of plant characteristics and operational parameters on cutting-force requirements.