To reduce handling costs at a leading UK manufacturer of pharmaceutical products, two industry-standard forklift trucks have been supplied in modified form so that they can travel between the warehouse and factory without the need for drivers. The work was carried out by E&K Automation, a company specialising in the manufacture and implementation of AGV (automated guided vehicle) systems.

This pharmaceutical installation is a good example of how a simple, stand-alone AGV network can be cost-effectively configured with laser guidance and radio communication to operate independently of existing factory systems. A further feature is the ease with which the layout was subsequently modified in 2011, after several years of operation, to make space for an additional production line.

The automated straddle-stacker trucks, which were originally supplied in 2007, transport mainly packaging materials from the warehouse to production. After packing, product is taken on pallets to a wrapping station, after which they are moved to a finished goods warehouse.

Previously, operators driving ride-on pallet trucks moved goods between the warehouse and factory over two and sometimes three shifts per day. Eliminating the associated labour costs soon justified investment in the automated system.

A notable feature of the installation is that the factory is some two metres higher than the warehouse, the height difference taking place over a 70 metre long ramp. The near three-degree incline is significant and had to be taken into account when the vehicles were engineered to carry loads weighing up to one tonne at 1 m/s up and down the ramp. AGV speed increases to a maximum of 1.5 m/s on the flat to maximise handling productivity.

With simplicity of operation in mind, another feature of the system is opportunity charging of the battery on board each vehicle at either of two designated stations on the route, eliminating the time-consuming task of exchanging a battery when it nears depletion. The cost of two additional swap-out batteries is also avoided.

Communication and control
Under normal circumstances, communication between the AGV system central controller and vehicles would be via an existing wireless LAN (local area network). In this case, however, E&K supplied a completely stand-alone, narrowband radio communication system to avoid accessing existing factory systems and so remove the need to obtain re-approvals from the international drug authorities.

The AGV central control computer monitors the location of the vehicles and manages their movement automatically to optimise material flow. An HMI displays a real-time mimic of the system showing the positions of the vehicles and presenting other system data.

Transport orders are triggered by ceiling-mounted sensors that check the status of pallet pick-up and drop-off locations in the warehouse, production and wrapping areas.

The two vehicles transport around 140 pallets from the warehouse to production during a typical double-day shift from 6.00 am to 10.00 pm. Pallet movements during the night are around 30. The respective numbers of movements in the opposite direction are 100 and 20. Standard 1,200 mm x 1,000 mm wooden and aluminium pallets are handled, as well as 1,200 mm x 800 mm wooden Euro pallets.

Layout modification
In late 2010, the customer decided to add a new production line. The only access for construction of the new line was via the original AGV pick-up and drop-off area for finished goods. So that part of the AGV layout, along with one of the automated battery charging stations, was moved by E&K to a more convenient location.

These alterations were particularly straightforward due to the autonomous nature of the AGV operation and the flexibility of E&K's design and control tools. If more AGVs are needed to support production increases in the future, this will be similarly easy to achieve.

Globally, some of the leading names in pharmaceuticals manufacture are users of E&K AGV systems. Peter Holdcroft, managing director of E&K Automation in Bramley, Hampshire, advises that industry figures show that every year the pharmaceutical and life-sciences sector are usually in the top four industries investing in this type of materials handling automation. Only the automotive, food / beverage, and print / paper sectors install larger numbers of AGV systems.