Shadow Removal in Acquired Image for Visual Servoing of Unmanned Ground Vehicles
Kundala Sandeep, Eswaran Parthasarathy, L Prathibha, CVRDE · International journal of intelligent engineering and systems · 2018
Vision-guided robotic operation is one of the new concepts in teleoperated Unmanned Ground Vehicle (UGV) for military applications.The objective of the Visual Servoing (VS) is to control the position of the robotic arm using the data such as the distance of an object from the reference frame, or the length and width of the object extracted from the vision sensor.In Image-Based Visual Servoing (IBVS) scheme, position control values are computed from image features directly.This work proposes the technique of shadow removal of the object through the advanced light model from the image, acquired using a monocular camera.The 2D spatial coordinates and Pointof-Contact (PoC) of the object with reference to the ground plane is computed using straight-line equations.PoC analysis is made through mapping of pixel distances to spatial distances to analyses mean pixel distance, and the percentage of error obtained between actual distance and calculated distance computed.Other parameters like the width of the object and, the distance between the camera and object is also estimated.The computed result yields a maximum error of 3 cm and shows 2.6% error for camera fixed at the height of 160 cm with a tilt angle of 50˚, which covers an area of 150 cm x 120 cm.