Automated storage and retrieval system

AS/RS systems are designed for automated storage and retrieval of parts and items in manufacturing, distribution, retail, wholesale and institutions. They first originated in the 1960s, initially focusing on heavy pallet loads but with the evolution of the technology the handled loads have become smaller. The systems operate under computerized control, maintaining an inventory of stored items. Retrieval of items is accomplished by specifying the item type and quantity to be retrieved. The computer determines where in the storage area the item can be retrieved from and schedules the retrieval. It directs the proper automated storage and retrieval machine (SRM) to the location where the item is stored and directs the machine to deposit the item at a location where it is to be picked up. A system of conveyors and or automated guided vehicles is sometimes part of the AS/RS system. These take loads into and out of the storage area and move them to the manufacturing floor or loading docks. To store items, the pallet or tray is placed at an input station for the system, the information for inventory is entered into a computer terminal and the AS/RS system moves the load to the storage area, determines a suitable location for the item, and stores the load. As items are stored into or retrieved from the racks, the computer updates its inventory accordingly. The benefits of an AS/RS system include reduced labor for transporting items into and out of inventory, reduced inventory levels, more accurate tracking of inventory, and space savings. Items are often stored more densely than in systems where items are stored and retrieved manually. Within the storage, items can be placed on trays or hang from bars, which are attached to chains/drives in order to move up and down. The equipment required for an AS/RS include a storage & retrieval machine (SRM) that is used for rapid storage and retrieval of material. SRMs are used to move loads vertically or horizontally, and can also move laterally to place objects in the correct storage location. Storage and Retrieval Machines pick up or drop off loads to the rest of the supporting transportation system at specific stations, where inbound and outbound loads are precisely positioned for proper handling. In addition, there are several types of Automated Storage & Retrieval Systems (AS/RS) devices called Unit-load AS/RS, Mini-load AS/RS, Mid-Load AS/RS, Vertical Lift Modules (VLMs), Horizontal Carousels and Vertical Carousels. These systems are used either as stand-alone units or in integrated workstations called pods or systems. These units are usually integrated with various types of pick to light systems and use either a microprocessor controller for basic usage or inventory management software. These systems are ideal for increasing space utilization up to 90%, productivity levels by 90%, accuracy to 99.9%+ levels and throughput up to 750 lines per hour/per operator or more depending on the configuration of the system. == Horizontal carousels ==

Robotic Inserter/Extractor devices can be used for horizontal carousels. The robotic device is positioned in the front or rear of up to three horizontal carousels tiered high. The robot grabs the tote required in the order and often replenishes at the same time to speed up throughput. The tote(s) are then delivered to a conveyor, which routes it to a work station for picking or replenishing. Up to eight transactions per minute per unit can be done. Totes or containers up to 36" x 36" x 36" can be used in a system. On a simplistic level, horizontal carousels are also often used as "rotating shelving". With simple "fetch" command, items are brought to the operator and otherwise wasted space is eliminated. AS/RS Applications: Most applications of AS/RS technology have been associated with warehousing and distribution operations. An AS/RS can also be used to store raw materials and work in process in manufacturing. Three application areas can be distinguished for AS/RS: (1) Unit load storage and handling, (2) Order picking, and (3) Work in process storage. Unit load storage and retrieval applications are represented by unit load AS/RS and deep-lane storage systems. These kinds of applications are commonly found in warehousing for finishing goods in a distribution center, rarely in manufacturing. Deep-lane systems are used in the food industry. As described above, order picking involves retrieving materials in less than full unit load quantities. Minilpass, man-on board, and items retrieval systems are used for this second application area. Work in process storage is a more recent application of automated storage technology. While it is desirable to minimize the amount of work in process, WIP is unavoidable and must be effectively managed. Automated storage systems, either automated storage/retrieval systems or carousel systems, represent an efficient way to store materials between processing steps, particularly in batch and job shop production. In high production, work in process is often carried between operations by conveyor system, which this serve both storage and transport functions. Inventory Category-specific AS/RS Each inventory category—raw materials, work-in-process, and finished goods—requires its own specialized Automated Storage and Retrieval System (AS/RS). Particularly for work-in-process (WIP) inventories, due to variations in manufacturing processes, the AS/RS systems are significantly different in design and function, tailored specifically to match unique handling, storage, and retrieval requirements Installed applications Installed applications of this technology can be wide-ranging. In some libraries, such as at University of Nevada, Reno library, such a system is employed to retrieve books. Still others in use involve retrieval of bicycles from a bicycle tree, as in the case of systems in Japan. Institutions using automated storage and retrieval systems Some examples of academic institutions using automated storage and retrieval systems are; • University of British Columbia, Vancouver, British Columbia • California State University, Long Beach, Long Beach, California • California State University, Northridge, Northridge, California • University of Central Florida, Orlando, Florida • Chicago State University, Chicago, Illinois • University of Chicago, Chicago, Illinois • Colgate University, Hamilton, New York • Cornell University, Ithaca, New York • Defense Visual Information Center, March Air Reserve Base, Riverside County, California • Eastern Michigan University, Ypsilanti, Michigan • Georgia Southern University, Statesboro, Georgia • Grand Valley State University, Grand Rapids, Michigan • Liberty University, Lynchburg, Virginia • University of Limerick, Limerick (Ireland) • University of Louisville, Louisville, Kentucky • Macquarie University, Sydney, Australia • Marywood University, Scranton, Pennsylvania • University of Missouri–Kansas City, Kansas City, Missouri • University of Nevada, Las Vegas • University of Nevada, Reno • UTS Library, University of Technology Sydney • North Carolina State University, Raleigh, North Carolina • Santa Clara University, Santa Clara, California • Sonoma State University, Rohnert Park, California • Tri-County Technical College, Pendleton, South Carolina • University of Utah, Salt Lake City, Utah • Utah State University, Logan, Utah • Christopher Center, Valparaiso University, Valparaiso, Indiana • Waseda University, Tokyo (Japan) == Types ==

• Vertical Lift Storage Modules (VLSM) - These are also called vertical lift automated storage/retrieval systems. All of the next AS/RS types are designed around a horizontal aisle. The same principle of using a center aisle to access loads is used, except that the aisle is vertical. Vertical lift storage modules, some with heights of 10 meters or more, are capable of holding large inventories while saving valuable floor space in the factory. • Unit load stackers - The unit load stackers is typically a large automated system designed to handle unit loads stored on pallets or in other standard containers. The system is computer controlled, and the S/R machines are automated and designed to handle the unit load containers. • ASRS Gantry Robots - These are a type of Automated Storage/Retrieval Systems used in warehousing and logistics sectors. Some common uses for these are in the Tire Industry for stacking tire inventory. Most of these systems span 50–60 ft in width and average 200–300 feet in length. These systems use End Effectors a.k.a. End of Arm Tooling to pick and place the tire stacks from conveyors. == Man-aboard systems ==

A man-aboard system can provide significant floorspace savings over manual or forklift operations but is not truly an AS/RS, as the operation is still manual. Storage system heights are not limited by the reach height of the order picker, as the picker rides along on the platform as it is moved vertically or horizontally to the various storage locations. Shelves or storage cabinets can be stacked as high as floor loading, weight capacity, throughput requirements, and/or ceiling heights will permit. Man-aboard storage and retrieval systems are far and away the most expensive picker-to-stock equipment alternative but are less expensive than a fully automated system. Aisle-captive storage/retrieval machines reaching heights up to cost around $125,000. Hence, there must be enough storage density and/or productivity improvement over cart and tote picking to justify the investment. Also, because vertical travel is slow compared to horizontal travel, typical picking rates in man-aboard operations range between 40 and 250 lines per person-hour. The range is large because there is a wide variety of operating schemes for man-aboard systems. Man-aboard systems are typically appropriate for slow-moving items where space is fairly expensive. ==Ergonomics and Safety==

Automated storage and retrieval systems (AS/RS) can enhance workplace ergonomics and safety by reducing the physical damage and repetitive tasks for workers. In healthcare and pharmaceutical warehouses, mini-load AS/RS and vertical lift modules (VLMs) are used to automatically pick and deliver them at waist height, these systems actually reduce physical harm to workers by handling the heavy lifting tasks. In automotive manufacturing, pallet-load AS/RS systems handle heavy components such as engines or transmissions, minimizing manual lifting and preventing worker back injuries. E-commerce warehouses use mini-load systems to handle very small products, bringing items directly to worker stations and reducing the same fatique problems. ==Workforce automation==

In the second decade of the 2000s, the first robotic models appeared on the market equipped with upper and lower limbs (rather than a trolley with a mechanical arm), radar/computer vision or sensors, and capable of recognizing the products, carrying out loading and unloading operations from the truck/shelves/forklifts, positioning the load units on the shelves, handling and picking of the order. == See also ==