Paper Title
Multi-Layer Obstacle Detection and Avoidance System using Lidar and Ultrasonic Sensor

Obstacle detection and avoidance system for man-made flying objects has been a topic of great interest over the years due to the increasing number of air accidents/ incidents reported all over the world. A flying object during its flight must evade encountering obstacles like towers, walls, wires, trees, high tension grid wires, hills etc for the safety of the precious aircrew lives and the costly flying object. Most of the advanced obstacle detection and avoidance systems uses stereoscopic imaging, embedded stereo vision and laser based technologies. The Obstacle detection and avoidance system can be used for military drones and unmanned aerial vehicles, which executes the vital task of information gathering pertaining to terrorists and to carry out area surveillance in low intensity conflict areas of Jammu and Kashmir and North Eastern states. The system will also have a diversified use in search and rescue of casualties during disasters. In this paper we propose a reliable and robust design of quad copter based obstacle detection and avoidance with features such as LIDAR sensor integrated with ultrasonic sensor as a redundancy for evading obstacles during the flight. In our proposed system, the obstacle will be first sensed and then according to the programmed pattern the flying object will find a new path and execute its mission and in case of the path is not determined, the flying object will return to its launching station. Keywords - LIDAR Sensor, Ultrasonic Sensor, GPS, DSP Circuit (FFT).