Inertial guidance of AGV Essay

Inertial guidance can operate in nearly any environment and incorporates the use of a highly accurate gyroscope to measure the AGV direction, odometric wheels and magnetic sensors to locate the AGV. A sensor beneath the AGV detects the presence of the magnets inside drilled holes in the floor. An embedded system controls, assigns tasks to the vehicles and adds new courses. Transponders embedded in the floor are used to verify that the vehicle is on course. A gyroscope corrects the direction of the vehicle in order to keep the AGV on its path [4][13].
Magnets in the floor can be set in different sequence combination that contain unique position codes to communicate to the AGV its location in comparison to its expected location. Since the magnets are spaced out, are cheap, flexible and have easy installation, they can be used as a feasible alternative to wire [8].
Wears in a gyroscope can cause an AGV to be steered off course, with the additional problem that path deviation at constant velocity cannot be corrected without additional guidance systems if the plant needs to offer accuracy over time [8]
Beacons are placed in strategic locations around the plant and the vehicle is pre-programmed with their exact location. As the vehicle navigates, it receives signals from at least three transmitting beacons and uses that information to determine its location and destination, adding flexibility to this type of guidance. Changes required by the client can be made by software [8].
The system requires triangulation and additional programming during installation so that the AGV knows the exact location of all of the beacons. There is also an increased cost due to the more complex controller, the beacon transmitters and the vehicle's receiver
Dead-Reckoning is a non-wire system that uses an optical encoder on the drive wheels to measure rotation and steer angle, having the position of the AGV calculated by a microcontroller based on the starting position, the internal map and other information [8].
The dead-reckoning guidance system is flexible, but require smooth surfaces to avoid wheel slippage, which cause vehicles to get off track, and heavy loads (they can cause deformation on the wheel), as well as debris in the path or on the wheels of the AGV. This system is less expensive than the laser system since an inexpensive general-purpose controller can be used, but it is not as reliable since it does not have absolute reference points that don't change
Reference [14] presents a 2009 questionnaire-based online survey that aimed to identify key areas requiring research and development activities in automotive industries that could provide understanding and solutions for the needs, potentials, obstacles and pitfalls of applying mobile service robots in companies and in the industrial sector.
This survey was conducted because of the worldwide economic significance of this particular industry and its needs for research and innovation. To understand its current situation, its needs, gaps and pitfalls of industrial service robots by the potential industrial users is therefore important [14].