Development of Pose Stabilization System for Septic Tank Sampling Using Wire-driven Mechanisms and Passive Gimbal Structures

This study presents a wire-driven automatic sampling system for septic tank environments. A wire-driven mechanism was adopted for a wide working range and easy installation on existing facilities. The system utilizes three cables and motors to control a platform with three degrees of freedom. To enhance stability, wire attachment points were centralized to minimize eccentric moments, and a passive gimbal structure was integrated to maintain a horizontal attitude. Cable lengths were derived via kinematic relationships, with Jacobian-based control generating motor commands. The sampling unit performs descending and sealing motions for effective collection. Furthermore, during acceleration and deceleration, the platform’s roll and pitch angles fluctuated by less than 3°, returning to a state of static equilibrium. These quantitative findings verify the feasibility and structural stability of the proposed system for practical wastewater monitoring applications.