Automated lift trucks offer industry-changing technology

Hands-free, operator-free brings an existing warehouse solution to a new audience.

08/10/2012


As ALTs begin to appear on plant floor, they may extend the idea of a more automated warehouse and create new opportunities. Photo courtesy: The Raymond Corp.Automated guided vehicles (AGVs) were first used in material handling nearly 60 years ago. They were purpose-built vehicles designed and assembled by specialized companies to do specialized tasks for specific customers. AGV firms could design and install the systems but offered little, if any, local service and support. The market was relatively small compared with lift trucks, with just a few dozen AGV systems using a few hundred automated trucks being installed each year.

As technology continues to advance and as lift truck manufacturers start integrating automation capabilities into their trucks, the market for a new generation of automated lift trucks (ALTs) will grow. This new generation of ALTs is expected to change the market dramatically. ALTs are different from AGVs in significant ways that make them more affordable and easier to use, ultimately enhancing their acceptance by the marketplace.

AGVs pave the way for automation

Early on, AGVs typically were used in process industries or manufacturing facilities to deliver parts or raw materials to the production line, or to transport work in process along the assembly line. They also were used in the publishing industry, such as in newspaper printing plants, to deliver massive rolls of paper to the presses.

In short, AGVs were expensive, complex systems of machines built to travel the same fixed paths, transporting the same or similar goods over and over again with limited or no human intervention. It took months, if not years, to design, build, install, and bring AGV systems up to full operational potential. They were inflexible, and once installed it was not easy to modify a system. The significant investment in time and money was justified primarily by the labor cost savings and the ability of AGVs to run 24/7/365 without coffee breaks, vacations, or sick days.

Today, conventional AGVs are still a niche market with a few hundred trucks sold per year, mostly into the same types of manufacturing plants, process industries, or printing plants that have been their traditional market. While the technology has improved somewhat, the limitations on traditional AGV technology, suppliers, and systems haven’t changed significantly. The vehicles are still very expensive, complex, inflexible, and built by companies that specialize in AGVs and offer limited field service and support. 

ALTs add flexibility

Perhaps the most significant differences between AGVs and ALTs is that ALTs don’t require lasers, tape, wire, or magnets for guidance. Routes can be set up quickly with no changes to a building’s infrastructure and no integration with IT, ERP, or warehouse management systems. This means ALTs can learn routes and begin doing useful work in a matter of hours instead of the weeks or months required to implement AGV systems. It also means ALTs are more flexible. While ALTs run on preplanned routes, those routes are not fixed but can be modified as needed. Additional routes can easily be added, removed, or adapted to suit throughput needs from season to season, week to week, or shift to shift. Any route that must be repeated where an operator isn’t necessary can be programmed, including runs to battery room and back. 

If an ALT has no fixed routes, how does it know where to go? Very simply, a human teaches it what to do. While “under the hood” the technology is complex, teaching routes and using the truck are easy. An ALT “learns” routes and the actions to perform on a route while an operator drives it. As an example, on the Raymond ALT, a Seegrid multi-head camera system records image data while the truck is being driven. Then the Seegrid software and hardware convert image data into a travel path the truck can follow. If the truck senses an obstruction, it will slow down and eventually stop until the obstruction is removed, and then continue on its way. An operator must manually load pallets, but the ALT will automatically drop pallets at preprogrammed locations.

Actions like horn honks, stops at intersections, and pallet drops are taught to the ALT by the operator driving it in learning mode. Those routes are then used when the truck is in automatic mode without the operator to transport material in the warehouse or manufacturing plant. Once saved, a route can be used as often as needed. Using the Raymond ALT, up to 15 miles of travel can be saved in a virtually unlimited number of routes.

Another significant benefit of ALTs is that they can be operated by a human in manual mode like a conventional lift truck. This “operator optional” capability affords some significant benefits. If the need arises, an operator can use the truck like a conventional lift truck just by stepping into the operator compartment and taking control of the handle. Traditional AGVs can’t do this. Most conventional AGVs don’t even have an operator compartment or on-board controls. 

Outlook: Rapid adoption of ALTs

Adoption of ALTs will happen relatively quickly in the lift truck industry over the next few years. New technologies are cheaper and easier to implement than ever before. The flexibility of ALT technology and the ease of installation and use will increase uptake. The ALT also will be capable of being powered by hydrogen fuel cells and advanced battery technologies.

Because ALTs look very much like conventional lift trucks with some additional features and can run in both automated and man-operated modes, workers will develop a higher comfort level with them more quickly. ALTs are “user friendly” and will be more readily accepted than old fashioned AGVs.

The ALT replaces manned vehicles or multiplies labor in warehouses and distribution centers, manufacturing facilities, and process industries for repetitive, horizontal transport tasks, including:

  • Completing long hauls in distribution centers
  • Moving goods from the dock to pick-and-drop (P+D) stations for put-away
  • Moving pallets from P&D stations to docks
  • Transporting materials from the end of a production line to the warehouse
  • Delivering components and parts to production lines 

Any facility that runs the same or similar routes repeatedly may find value in the ALT. Bigger operations moving a large number of pallets per shift over longer distances are the best applications for the ALT. Distribution centers may have less-regular route patterns and perform different activities on different shifts but can still benefit by automating repetitive horizontal transport assignments.

The flexible ALT, with its ability to store multiple routes and change routes easily, has significant technological advantages over old-fashioned AGVs, making it well suited for distribution centers and warehouses. Because they can be installed and start working in hours, rather than weeks or months, ALTs could even be part of a material handling dealer’s rental fleet and be deployed for peak season usage. Because operators are needed only to program ALTs, they also could be used in areas storing high-value goods or controlled substances, or in any parts of a warehouse or manufacturing plant where it’s preferable to have as few humans as possible for security reasons.

There are some limitations to ALT technology. An operator is required to load pallets on the forks; ALTs won’t do that automatically. Because the system is vision-guided, ALTs need adequate lighting when being taught and when running routes. They won’t run in “lights out” facilities. ALTs also need some geography to recognize and won’t work well in bulk stack areas that change frequently.

While enhancements are in development, ALTs currently can’t travel between freezers and ambient temperature areas because this temperature change causes condensation to accumulate on the camera lenses, inhibiting the vehicles’ vision. Also, there are no ALTs currently available for environments that require EE-rated trucks.

What to consider when thinking about using ALTs

ALTs are not intended to replace an entire fleet of lift trucks, but to reduce labor costs by leveraging and multiplying labor across several trucks. One person can easily manage three to four ALTs and perhaps more, depending on the lengths of routes and what other duties the operator is required to perform. A firm considering ALTs will need to do its own financial analysis of the benefits. In general, return on investment for ALTs is determined by several factors, including labor costs, number of shifts in which ALTs are used, the number of loads moved per shift, number of loads carried per trip, and distance per trip.

ALTs are automated lift trucks that offer significant advantages over AGVs in ease of use, lead time for implementation, flexibility, local service and support, and ROI. A variety of applications in virtually any industry could see improved throughput and reduced labor costs by using ALTs. 

Chris Cella is president of Heubel Material Handling Inc., a Raymond sales and service center. 



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