Perpustakaan Digital ITB

Underwater Remotely Operated Vehicle (U-ROV) is a robotic platform that can be used for various underwater applications. It can also be equipped with state-ofthe- art imaging sensor (camera) for data visualization. To produce blur-free imagery data, a stable platform of the U-ROV is needed particularly due to the unpredictable environmental conditions. In this paper, we present a stereo Image-based Visual Servoing (IBVS) controller for an in-house-developed ROV platform with an Intel RealSense D455 stereo camera. Stereo image rectification procedure is applied prior to feature extraction to mitigate refractive distortions introduced by the water–glass–air interfaces. By augmenting the third row of interaction matrix with depth features from stereo triangulation, the proposed method can resolves the sway–yaw coupling ambiguity inherent in planar IBVS formulations. We employ a PI-augmented control law to reduce steady-state error, and project the resulting camera velocity command onto the four controllable degrees of freedom of the vehicle—surge, sway, heave, and yaw—through a camera-to-body frame transformation. Experimental validation in an underwater pool environment demonstrates that the controller successfully drives image feature errors toward zero and stabilizes the U-ROV at the desired pose relative to an AprilTag marker under external disturbances.