Microcontrolling of an automated guided vehicle

Abstract

This project was the continuation of a previous one, accomplished in 1990, by Pierre Theuma and Julian Dimech, named "AUTOMATED OPTICAL GUIDED ALL WHEEL STEERED VEHICLE". In this project these two graduates in Mechanical Engineering constructed an Automated Guided Vehicle (A.G.V.) that was controlled by a Programmable Logic Controller (P.L.C.), which in turn activated, through its ladder programming, the Steering Motor and the Drive Motor of the AGV onto a fixed track. Yet this project, due to the use of a PLC, could not have a very versatile utilisation, and in fact could only stop at regular intervals, could not vary its speed to avoid loss of track at bends, could not choose where to stop discriminately or choose other tracks. The intention of the newly formed Department of Manufacturing Engineering, headed by Mr. F.E. Farrugia, M.Sc., C.Eng., MIEE, MIQA, Eur.lng., under the Faculty of Mechanical and Electrical Engineering, wanted to utilise this AGV in a global system that could be totally automated. But the modifications on this AGV had to be done and so, when the proposal was put forward, for the "MICROCONTROLLING OF AN AGV" it was accepted by Mr. Farrugia. This involved using a microprocessor controlled system on the AGV that could be more versatile than the PLC. The original structure was maintained and so was the gearing system designed in 1990. So the task included the designing of the microcontroller's main board, the driving boards for the motors, ( done by Pulse Width Modulation - P.W.M. ) and also the external circuitry that was necessary to implement such a system, such as new sensors and a new concept of controlling the AGV, through the software control, written in the Erasable Read Only Memory ( EPROM ) of the microcontroller. This dissertation is intended to serve as a manual for those who in future will want to utilise the AGV for the aforementioned purpose or those wanting to make improvements. Through this and the dissertation of Julian Dimech and Pierre Theuma, and also by the recommended literature, one can understand how the AGV works, how it can be programmed for any type of task, and how to set all the parameters necessary to operate this AGV efficiently. With the Microcontroller on board, the AGV can now stop at predetermined stops, take multiple paths and control the speed and the direction of the motors. It is up to the programmer to make or utilise the AGV to its full extent. But first, he or she must undergo a detailed examination and read all the relevant material and individuate, study and set the parameters for the AGV to function in a real but predetermined ambient conditions. Finally there was the construction of a prototype stand-alone model of the AGV that simulated in part a real AGV, so showing the utilisation and versatility of the designed microcontroller. This was done as the AGV­ was could not be modified, so the model is only for demonstrative purposes.