AgroCableBot: Experimental Validation of a Reconfigurable Cable-Driven Parallel Robot for Precision Agriculture and Crop Monitoring

Precision agriculture requires robotic platforms capable of covering large cultivation areas while providing accurate positioning for localized crop monitoring and management operations. Cable-driven parallel robots (CDPRs) offer large workspaces and lightweight moving structures; however, their usable workspace is constrained by cable tension requirements. This study presents the experimental validation of AgroCableBot, a reconfigurable CDPR for precision agriculture previously proposed by the authors, in which the proximal cable attachment points are vertically reconfigured to increase the wrench-feasible workspace (WFW). Previous simulation results showed that this reconfiguration increases the WFW from approximately 58% to 100% of the geometrically admissible workspace for a minimum cable tension of 5 N. In this work, a physical prototype with adjustable anchor height was built, and a vision-based sensing system was integrated for end-effector localization, automatic calibration, and closed-loop trajectory tracking. Experimental validation included square and circular trajectories and an agricultural inspection trajectory over a seedling tray, executed at three anchor heights (400, 600 and 900 mm). The system achieved a three-dimensional RMSE between 1.9 and 2.6 mm, a 95th-percentile error below 4.5 mm, and a maximum tracking error of 6.0 mm, measured with the vision system. These results demonstrate the potential of AgroCableBot as a reconfigurable robotic platform for accurate crop monitoring and localized agricultural operations in protected cultivation environments.