Fiber-Grating-Based Vision System for Real-Time Tracking, Monitoring, and Obstacle Detection

There is a real need to develop a sensory system that can monitor and track the behavioral status of a person in real time while protecting his/her privacy. In addition, it is important to have the ability to detect stationary and moving objects in real time to support dynamic navigation needs for mobile robots. This paper describes the development of intelligent fiber-grating (FG)-based 3-D vision sensory system that enables real-time object detection, monitoring, and tracking. This system uses the richness and the strength of the vision while reducing the data load and computational cost by encoding the working space using a limited number of spatially interrelated 2-D laser spots. The sensor system generates the laser spots by projecting a coherent laser beam on two perpendicularly overlaid layers of FGs. The presence of a target within the visible operational view of the sensor disturbs the part of the projected laser spots´ pattern where the target appeared. By calculating the displacement of the disturbed spots within the CCD image plane, the sensor system can detect, in a short time, an object/human and provide relevant information in terms of range, approximate shape, and position. To facilitate faster detection and real-time tracking, the author has developed two strategies that decompose the working space into zones and virtual planes