Low-Profile, Single-Bin AGVs Can’t Compete with a Tugger AGV

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Low-Profile, Single-Bin AGVs Rarely Better Than a Tugger AGV

Reports that small, low-profile, single-bin automated guided vehicles (AGV) capable of light load, small-bin pickup and transport will soon take over warehouses, distribution centers, and manufacturing plants are exaggerated. Sure, when Amazon bought Kiva years ago for a little less than a billion dollars, it had the deep pockets to invest in that kind of infrastructure. Since that time there is a whole new generation of low-profile “bots” that have failed to catch on with any significance. There is a reason: Price.

As cool and sexy as these small robots may be, their ROI is almost always more than a year, often many years. For GE Healthcare, Toyota, and others, there is a willingness to ignore the initial price tag and buy the Ferrari; for the rest of the industry, when pulling a string of industrial carts, a driverless tugger will do just fine.

Even progressive organizations committed to ergonomics and lean manufacturing principles have recognized that these new, single-bin AGVs are not yet sufficiently tested and often fail to provide the promised results. We have been told that, in the case of order fulfillment, the implementation was far more complex than promised, more human touches were required, and ongoing human interaction was required to make the system work (not really “walk-through driverless,” as promoted).

The promises made to third-party logistic (3PL) providers from small-footprint robotics present an application that will never work in 3PL. These companies will go after the segment all they like, but single-bin movement will never be a viable alternative until the cost per AGV comes down to the less than the $10K range. There are simple math and ROI constraints.

A single person can carry more than one bin at a time and be far more efficient than a bin on a standalone AGV. This is different with a tugger AGV, a device that is purposely designed to tow multiple carts of heavy loads, since it can utilize its efficiency of scale to move hundreds of pieces of product. Due to tugger capacity and with appropriate care, a tugger AGV can carry any type of product. The argument against tugger AGVs in this space is their physical size, but there are tuggers with a small footprint and a 1,000-lb towing capacity: the Vecna Tugger, for instance.

autonomous tugger amr/agv

The High-Capacity Autonomous Tugger

To be fair, there are other tuggers, but some have too many bells and whistles that raise the price point. With an effective leasing program, a Vecna Logistics tugger costs less per month than paying a forklift driver ($3,500 per month) with benefits; the result is instantaneous ROI.

It may not make sense to have a fleet of 50 tiny, single-use bots running around that need maintenance, when a simple tugger route (there is always a simple tugger route) can move the same material with a fraction of the number of AGVs.

Keep in mind, that although no vendor ever discusses maintenance, it must occur, and then the purchasing decision reverts back to simple math. Low-maintenance tuggers are the way to go for 95 percent of the materials handling market.

The bot solution of single-bin automatic bin picking is not ready for wide-market acceptance because the cost per individual bot is too high, usually in the $35,000 range per robot. Certainly, conceptually, as a goods-to-person solution, single-bin AGVs will be a game changer in the future. They eliminate nonvalue-added work within a facility. But when viewed as a total cost for solution, it becomes extremely expensive in the current pricing per AGV.

The more traditional tugger solution of manually loaded carts (although carts can certainly be automatically loaded) has a much better value. The tugger solution in a simple “supermarket” concept has a cost less than $100,000 and can move orders-of-magnitude more product. The beauty of the “supermarket” tugger concept is that it utilizes existing labor that is nearly impossible to displace in roles such as picking of product for the bins. Because this labor can’t be eliminated and is present in both systems, the transport method and its overall efficiency vs. cost is the telling factor. Today, the traditional tugger is still the winner.

This article was originally published in Quality Digest

About the Author
John Hayes, vice president of sales and logistics for Vecna Robotics, is a widely respected thought leader for the manufacturing, distribution, and materials handling industries. For more than 20 years Hayes has been evaluating, designing, developing, and implementing innovative software and hardware solutions with a particular focus in the automated guided vehicle space. Hayes is a supply-and-demand chain executive and a Pros-to-Know recipient.