Automatic Guided Vehicle (AGV) System Technology

Garry A. Koff, President, Savant Automation, Inc.

AGV systems are a proven solution for lowering labor costs, reducing damage, improving safety and control of material movement in a facility. But, these benefits are critically dependent on the quality of a buyer’s evaluation of factors which are clearly visible, yet dangerously hidden.

Most buyers choose an AGV supplier primarily based on what they see—the AGV itself, its navigation and the system price. That can be a fatal mistake, because it may lead to living with what they don’t see—a System Technology that results in an unsatisfactory system operation. System Technology comes with the choice of AGV supplier and, if that is not fully evaluated, the rest does not really matter. Would you buy a Ferrari if there were no (or poor-condition) paved roads (technology) on which to drive it?

Truly successful systems are more dependent on the System Technology employed than the actual AGV (automatic guided vehicle) employed. Yet, most potential buyers of AGV systems fail to appreciate this is the most critical part of an AGV system.

Like any type of automation, AGV “systems” rely on “technology.” Without System Technology (paved roads), you just have AGVs (Ferraris) incapable of performing work efficiently (driving/handing as designed). With the wrong type of System Technology, you end up with a deficient level of system operation and performance, or worse: a failed project.

AGV System Technology capability/functionality levels vary greatly with different AGV suppliers, so failing to evaluate this is a huge risk. But it is avoidable.

If you fail to understand & weigh the differences in AGV Technologies before you select a vendor, you’ll never stop paying for a bad decision. You can’t buy AGVs without getting the System Technology that comes with them. So, how do you avoid the risk of getting the wrong (i.e., mismatched to your application requirements) System Technology, when you can’t easily see a big part of what you’re buying?

The best way to insure you purchase a successful AGV system is to ‘do your homework’. Be sure to research before you select a supplier.

Here’s how:

1. Identify the functional elements of System Technology [Done-See Items 1-8 List, below]
2. Learn how each element functions for each different Supplier’s System Technology [Ask the Supplier to explain]
3. Create a list of decision factors [throughput rates, ease/cost of changes, expandability, level of control, maintenance, interface functionality, etc.] important to your system’s operation.
4. Compare how well the functional elements in different Suppliers’ System Technology addresses your list of the important decision factors.
5. Choose the AGV System Technology that is best matched to decision factors.

System Technology is what:

1. Allows AGVs to be routed to specific destinations by taking the shortest paths.
2. Insures AGVs exercise efficient, safe traffic control to maximize throughput.
3. Enables AGVs to perform the necessary station cycles that transfer loads automatically.
4. Provides the capability to interface with other automation such as robot cells, conveyors, storage systems, doors, etc.
5. Supplies the ability to communicate with AGVs to monitor their status and remotely dispatch them to carry out load transportation missions.
6. Establishes rules governing path layout limitations.
7. Determines how path actions like change sped, sound horn, activate turn signals, etc. are created.
8. Supports the networked integration with higher level control systems (MES, WMS, etc.) allowing the AGVs to be an embedded subsystem of a larger integrated system.

All the System Functions are handled by the System Technology that you don’t see. This invisible technology is what allows AGVs to work as a system. Yet, so many buyers know little to nothing about the critical differences in how each AGV supplier’s technology executes these system functions, and that is what can sink your system. Most on board the Titanic never saw what sank it.

Differences in AGV supplier System Technology affect everything in your system, from throughput/efficiency, response time, scalability, control & functional capabilities, ease/cost of change, reliability, operator interface, operational cost, to user acceptance & support, etc.

Failing to “see” (understand) the System Technology (below the iceberg surface) that you will get with your choice of AGV and its type of navigation (pieces you see) is like buying a house based on just seeing the outside and never going in to see if there are rooms; stairs to other levels; or even wiring, heating or floors.

Example: There has been lots of talk about a new form of navigation called “Natural Navigation.” It uses a Lidar laser scanner at floor level to see structural (natural) reference objects (walls, racks, etc.).  The system area must first be carefully scanned with the AGV to establish where the natural references are relative to the intended travel path.

The focus is all about what you “see” (the vehicle and its navigation) but, it should be on what you don’t see (the System Technology below the iceberg surface), because it is seriously deficient compared to the AGV System Technology found in proven forms of “virtual path” CAD map (Inertial/magnet or laser/target).

In fact, Lidar does not possess the associated System Technology required to handle typical AGV system applications. And, most facilities have open aisles (not walls on either side of the aisles) and, thus, lack the line-of-sight to building structures required by Lidar.

Failing to question and evaluate what you don’t see is a big risk. “Going inside an AGV system” is hard, because most suppliers keep you in the dark. It is your job to make potential AGV suppliers open the door to their System Technology house, “turn on the lights” and walk you through—so you see what is inside before you choose your AGV system supplier.

A System Technology Checklist will help you do your homework before buying. WMHS