Load modeling for sharp V-cutter cutting litchi (<i>Litchi chinensis</i> Sonn.) stalk

Abstract

Integrating picking institutions with autocontrol method led to the development of a new innovative ‘hand-held auto-picker’ for litchi (Litchi chinensis Sonn.) harvesting. Cutting load is a key parameter for ‘hand-held auto-picker’ operation. However, there is still no suitable model for cutting load setting. Hence, a model describing the relationship among cutting load, blade angle and friction coefficient was developed for cutting operation by sharp V-cutters. The model was based on analysis of mechanics of materials. A testing-equipment was developed and a series of tests was designed to verify such model. Results indicate that the cutting force trend-line calculated by the model is very similar to test results, but the calculated trend-line is much smoother. When radius of sample is between 5 and 7 mm, the calculated results were very approximate to the average of test results.

Key words: Litchi, picking, cutting force, model.