VLSI architecture-based implementation of motion estimation algorithm for Underwater Robot Vision System
DOI:
https://doi.org/10.31838/jvcs/06.02.13Keywords:
Motion Estimation, Underwater Robot Vision, Computer vision, FPGA, Velocity.Abstract
Motion Estimation (ME) is a computationally intricate issue often affected by non-exact solutions. Consequently, it is imperative to embrace many methodologies and assumptions. Velocity is an essential variable for Underwater Robot Vision (URV) navigation, yet its
estimation poses significant challenges. Conventional techniques, such as the Global Positioning System (GPS), are ineffective underwater, while alternative approaches need to calculateocean current's velocity or employ sound sensors. Nonetheless, these systems possess inherent limits. A viable method to calculate the velocity of URVs is through the utilization of Computer Vision (CV) systems when a marine structure is inside the URVs field of view, as these sensors are not affected by the same issues as acoustic routing or the influence of ocean currents. This study devised an algorithm that estimates a vehicle's rotational velocity (RV) and axial velocity (AV) by utilizing the motion field derived from the optical ME technique. The algorithms were evaluated in simulated settings, and the findings were shown using several approaches for ME. The ME method was found to function as predicted, with a maximum error of 2.23% in the conducted tests, and showed greater robustness under challenging underwater situations. This work also presented a hardware Programmable Gate Arrays (FPGAs) to enable real-time computation of dense optical motion for Video Graphics Array (VGA) images, utilizing the ME method.