Development and Field Evaluation of a Hydraulic Arm Integrated With an E‐Vehicle for Robotic Cotton Picker

ABSTRACT In cotton picking, there is a need for a robotic arm that can pick bolls efficiently with minimal loss and damage to immature bolls. This study addresses that gap by developing a hydraulic arm to work effectively in unstructured cotton fields. A three‐degrees‐of‐freedom hydraulic arm was developed with vertical, radial, and rotational movements, equipped with a roller‐type end‐effector and vacuum suction system to pick cotton bolls from the plants and collect them into a storage tank. The performance of the hydraulic arm was evaluated in the field under varying conditions of plant‐to‐plant spacing (250, 350, and 450 mm) and at suction pressures (25, 50, and 75 mmHg). Key performance parameters such as picking efficiency, picking capacity, damage of green bolls, losses of cotton bolls, and trash content were evaluated. The results indicated that the maximum picking efficiency (92.79%) and capacity (567 bolls picked/h) were achieved at 450 mm plant‐to‐plant spacing and 75 mmHg suction pressure, with minimal damage of green bolls (126 bolls/ha) and losses of cotton bolls (3.79%). The lowest trash content (2.06%) was observed at 450 mm spacing and 25 mmHg suction pressure. Finally, the hydraulic arm achieved precise and accurate cotton picking in complex cotton fields, showing the best performance at 450 mm plant‐to‐plant spacing and 75 mmHg suction pressure.