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.
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
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
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.
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.