Components of an AS/RS

The major components of an AS/RS are:

• Storage and Retrieval machine (shuttle crane or stacker crane),
• Storage structures,
• Transport devices (AGV, Conveyor, etc.), and
• Controls.

Storage and Retrieval Machine (S/R Machine)

The S/R machine is characterised through its capability to operate accurately and safely at high speeds, reach heights of 30 m or beyond that, and operate in aisles just only a few cm wider than the load it carries. The S/R machine can be completely automated and so easily controlled via a computer.

The current S/R machine runs on a floor-mounted rail and guided at the top. It comes in a wide range of sizes and configurations, since its design is a function of the load it carries and the work it performs. Speed is usually determined via the system's throughput requirements (that is how many loads require be storing and retrieving in an hour). Travelling speeds occasionally exceed 150 m/min when hoisting speeds can be as high as 50 m/min.

Storage Structure

The storage structure (racking) is a significant part of the AS/RS. It is different significantly from conventional pallet racking in that AS/RS storage racks are generally much higher and interface directly with the S/R machines, so making manufacturing and installation tolerances more critical. AS/RS rack design has to be provided for integration with S/R machine guide rails.

The most general storage structures are free-standing and installed inside a building. Specifications are different, depending on type of load to be stored and system configuration. Nowadays an increasing number of systems are rack supported: i.e., the rack storage structure supports the building itself. This type of system can be over 30 metres tall and is popular since it reduces construction time and cost.

Transport Devices

The transport (system) device moves the loads further than the limit of the S/R machine. A number of systems require only a conveyor, while larger and more complex installations need elaborate transport devices connecting the S/R with other factory operations. There are several types of transport devices which can be employed with an AS/RS: forklifts, overhead power, roller or chain conveyors, and free conveyors, in-floor tow-lines, shuttle trolleys and automated guided vehicles. The choice relies on the throughput needs, type of load to be handled, and degree of interaction with shipping, receiving, manufacturing, assembly and another plant operation.

System Controls              

The system controls include two functions, the control of equipment and the control of data. This computer control system might also perform tasks such as inventory control, data automation, networking control and is frequently related to an even larger corporate management information system computer.