Automatic Guided Vehicles have played a role in moving material and product for more than 50 years. The first AGV system was built and introduced in 1953. It was a modified towing tractor that was used to pull a trailer and follow an overhead wire in a grocery warehouse. By the late '50s and early '60s, towing AGVs were in operation in many types of factories and warehouses.
The first big development for the AGV industry was the introduction of a unit load vehicle in the mid 1970s. These unit load AGVs gained widespread acceptance in the material handling marketplace because of their ability to serve several functions: a work platform, a transportation device, and a link in the control and information system for the factory.
Since then, AGVs have evolved into complex material handling transport vehicles ranging from mail handling AGVs to highly automated automatic trailer loading AGVs using laser and natural target navigation technologies.
(source: MHIA - AGV elessons http://www.mhia.org)