ASABE Technical Library - Abstract
Member and Access Notice
Development of a Mobile Manipulator Robot for Autonomous In-Situ Soil Analysis in Chile Pepper Production
Published by the American Society of Agricultural and Biological Engineers, St. Joseph, Michigan www.asabe.org
Citation: 2026 ASABE Annual International Meeting 2600046.(doi:10.13031/aim.202600046)Authors: Roman Langenscheidt, Mahdi Haghshenas Jaryani, Heinz Bernhardt
Keywords: Chili Pepper, soil sensor, soil moisture, small robot
Abstract. Chile pepper production in New Mexico is increasingly challenged by water scarcity, soil salinity from groundwater irrigation, and labor shortages, contributing to declining yields in recent years. Precision agriculture technologies that enable spatially resolved and data-driven resource management offer a promising way to mitigate these constraints. This thesis presents the development and evaluation of an autonomous in-situ soil sensing system integrated with a mobile manipulator robot to automate reliable data collection under real field conditions.
The system combines several complementary subsystems: a two-stage visual alignment method using depth data from an RGB-D camera to first compensate for terrain slope and then select obstacle-free insertion sites; a force-based contact detection mechanism for identifying soil–sensor engagement; and an adaptive impedance control strategy with Kalman filter–based soil stiffness estimation to ensure controlled sensor insertion. The entire workflow, including monitoring, data acquisition, and failure handling, is implemented on a mobile robotic platform equipped with a 6-DoF manipulator and a TEROS 12 soil moisture sensor.
Laboratory experiments validated the performance of the individual subsystems across varied soil conditions and surface characteristics. Field tests conducted during the early chile pepper growing season further assessed system functionality, completing 41 sensing operations across three trials. Of all attempts, 75.6% successfully achieved full insertion with valid soil measurements, and 90.2% were classified as correct decisions, including justified aborts. Identified limitations included the visual alignment‘s inability to detect subsurface obstacles without surface expression, occasional false soil–sensor contact detections, and sporadic misclassification of full sensor insertion.
Despite these constraints, the results demonstrate the feasibility of autonomous in-situ soil sensing in chile pepper cultivation. The developed system establishes a foundation for advancing autonomous soil monitoring and provides methods that may extend to other crops requiring high-resolution in-situ soil characterization.
(Download PDF) (Export to EndNotes)