Visual Robot Guidance In Dynamic Environment Using Quadtree Data Structure And Parallel Processing

Abstract

ABSTRACT To guide a robot in a time varying environment, the initially planned path must be updated as the contents of the scene change. This research addresses the problem of planning a collosion free path for efficient visual guidance in scenes involving moving obstacles. Here we present a time efficient path planing based on quadtree data structure and parallel processing techniques, which is applied to the top view of a dynamic environment. Motion analysis is performed on a sequence of images taken from the top view of the scene in certain time intervals. The extracted motion information is then used for selecting the best path as the shortest distance nearer to the obstacle which is moving away from a reference point (e.g., camera, robot or a segment of initially planed path). 1. INTRODUCTION Robot navigation is a process of finding a collision-free path for a robot and guiding it through obstacles in a stationary or time varying environment. This process plays an important role in many applications of robotics and automation. It involves two processing steps; robot motion path planning and visual robot guidance. Path planing usually involves the analysis of the top view of a scene in a predetermined form. Results of the path planing is then used to guide a robot towards its destination without any collision. This involves the analysis of an image sequence representing the front view of the environment.In this paper, we consider the problem of determining a collision-free path for a robot using a sequence of images of the top view of a time varying scene. Despite their close resemblance, robot path planning in dynamic environment differs from the manipulator path planning in many aspects. This is because the manipulators follow the same path in their operations, while robots may follow different routes at different time instances. In addition, a robot does not have all the necessary information about its environment, and it has to find its path when it is moving along the certain direction. It obtains the visual description of the surrounding neighbor from a sequence of successive picture frames and based upon this information it determines its route.Considerable research effort has been devoted to study the robot path planning. For example, use of the ultrasonic range finders have been proposed to avoid collision with unexpected