Sonar Based Navigation: Follow the Leader for Bearcat III
Autonomous robots with mobile capability are finding lot of applications in manufacturing, medicine, space and defense. Design of such a robot is truly a daunting task. The issue is complex because the robot has to interact with its environment when performing the task One of the possible application for a robot might entail moving the robot through a dynamically decided safe path. Such navigation could be seen as a guiding of a series of mobile robots to a desired destination along a just decided safe path. Numerous research works has been done in the area of path planning and obstacle avoidance algorithms for navigating a robot intelligently through a unknown, unexplored Environment. This research work was done towards fulfilling the requirement of designing a mobile robot to follow a moving leader. The Center for Robotics Research at the University of Cincinnati has built a mobile robot named Bearcat II for the International Ground Robotics Competition being conducted by the Association for Unmanned Ground Systems (AUVS) every year. The objective is to make the Bearcat II follow a lawn mower driven by one of the judges while maintaining a safe distance of about 3 meters. A Polaroid ultrasonic transducer mounted on a micro-motor with an encoder feedback was used to track the co-ordinates and motion of the leader and the steering system is suitably adjusted for re-orienting the robot and to maintain the fixed distance between the robot and the leader. The readings of the sonar at the known adjustable angles are translated to the co-ordinate and relative motion of the leader. The Galil DMC controller suitably drives the left and right motor to steer the robot in the proper direction and at proper speed. This design yields a portable independent system, which could be suitably integrated or replaced with any different kind of sensor like a laser sensor, which could ascertain the position and motion of the leader.
School:University of Cincinnati
School Location:USA - Ohio
Source Type:Master's Thesis
Keywords:autonomous navigation robotics sonar based path planning
Date of Publication:01/01/2001