Autonomous Sensor Insertion and Exchange for Cornstalk Monitoring Robot

Abstract

Interactive sensors are an important component of robotic systems but often require manual replacement due to wear and tear. Automating this process can enhance system autonomy and facilitate long-term deployment. We developed an autonomous sensor exchange and maintenance system for an agriculture crop monitoring robot that inserts a nitrate sensor into cornstalks. A novel gripper and replacement mechanism, featuring a reliable funneling design, were developed to enable efficient and reliable sensor exchanges. To maintain consistent nitrate sensor measurement, an on-board sensor maintenance station was integrated to provide in-field sensor cleaning and calibration. While enabling the sensor exchange capabilities of this corn monitoring robot, the autonomous insertion capabilities was enhanced through two-finger gripper design and compliant soft-pads in the gripper finger tips along with position-based visual servoing implementation. The system was deployed at the Ames Curtis Farm in June 2024, where it successfully inserted nitrate sensors with high accuracy into 30 cornstalks with a 77% success rate.