Electrochemical impedance spectroscopy for pear ripeness detection and integration with robotic manipulators

The fruit grasping and maturity detection remain two distinct operational steps in quality grading scenarios. To achieve seamless integration of detection and grasping operations, this study designed a flexible manipulator integrated with maturity detection electrodes, which was used to collect fruit electrical parameters during the grasping process. Microscopic analysis, firmness testing, and physicochemical parameter evaluation were conducted to analyze the impact of maturity on electrochemical properties. Results showed that as pear maturity increased, firmness decreased, accompanied by significant changes in physicochemical parameters. Impedance measurements also increased with maturity, with low-frequency impedance rising from 864.575 kΩ to 2429.172 kΩ. Additionally, a support vector machine-based model was developed for accurate maturity classification, achieving high accuracy and recall. This study proposes a novel approach for non-destructive quality inspection in fruit grading scenarios.