A major food manufacturer has invested in a fleet of 25 self-guided vehicles (SGVs) for one of its production facilities in the UK. The SGV System was provided by FMC Technologies and replaces a 16 year old, obsolete wire guided AGV System. The fleet will handle Palletised Finished Case Goods for despatch to the UK and Europe. The SGVs are capable of transferring over 100 pallets per hour from the ends of production line palletisers to either shipping conveyors or ASRS storage conveyors. The new vehicles offer a number of benefits over the out-going fleet but increased capacity has been made possible because of the new bank of High Frequency (HF) chargers from Chloride Motive Power (CMP).
Each vehicle is powered by a CMP 'Classic' lead acid battery. The food manufacturer's Electrical Control Systems Engineer comments, “We specified CMP batteries and chargers for a number of reasons: the High Frequency chargers were already in use at another of our production facilities and we had been impressed by the performance and reliability.”
The SGV System and battery charging system work seamlessly together to ensure vehicles remain charged. When a self-guided vehicle approaches a pre-programmed state of battery discharge, it automatically manoeuvres to one of eight charging points. No human intervention is necessary as the SGV automatically positions itself on a charging plate on the floor, which is connected to a 48v, single-phase wall-mounted charger. The previous AGVs relied on a 24v on-board charger, which would be connected to an overhead power supply and required an 8 hour charge. Because of the 24/7 shift pattern operated at the factory, 6 AGVs would be recharging at any one time.
The new SGVs can be recharged within 5 hours and are also able to 'opportunity charge'. Opportunity charging allows the vehicles to automatically dock at a charging station when they are not in use, and receive a fast charge, which enables them to remain in operation around the clock. This means that there are usually only one or two SGVs on charge at any one time, freeing up more vehicles for material transport and allowing for maximized production.
Not only will battery life be extended for the new SGVs, but because they are laser guided, production is far more flexible. A rotating laser scanner placed on top of the vehicle detects reflective targets mounted on plant walls, to navigate its way through the facility. Vehicle guide paths can be changed, pick up and drop off points added, and system expanded quickly and easily. This also means that should the layout of the factory be re-organised, the system can easily be reconfigured.
Summing up, the Electrical Control Systems Engineer says, “We employ world-class production and maintenance practices and the AGV system offered real benefits. The new SGV fleet will build on these operational advantages. We managed to achieve a 5 or 6 year service life from our traction batteries and we are hoping to improve on this even further with the help of FMC Technologies and CMP; both companies have taken a 'team' attitude to this project – offering practical advice to our engineers and collaborating with each other. ”