Aug 08, 2019 by John Clark

Debunking the myths of AGVs vs. AMRs: Navigation

Part 1 of 4: characteristics, navigation, and paths of AGVs and AMRs / Blog Home / Debunking the myths of AGVs vs. AMRs: Navigation
Supply Chain Trends Automation

Part 1 of 4: Comparing and contrasting the characteristics, navigation and paths of Automatic Guided Vehicles (AGVs) and Autonomous Mobile Robots (AMRs)

AGVs are known for their ability to automatically move and pick material in manufacturing facilities and distribution centers. These workhorses of the supply chain have been doing that for well over half a century. In fact, these vehicles have made their name as a way to replace the time- and energy-wasting repetitive material movements of pallet loads.

Over the past few years, a new type of AGV has been appearing: the autonomous mobile robot, or AMR. These machines can handle unit loads like AGVs, but can also work with totes or cases. As the new kid on the block, AMRs have received a lot of media attention, claiming to be the next big thing in automatic, driverless mobile vehicles/robots, and claiming that they are superior to AGVs.

To prove this point, some have gone so far as to say that AGVs are a dead technology. It’s time to bust the myths and showcase that AGVs are not only alive and well, they’re thriving. In this post, we’ll look at 3 myths and work to dispel them.

MYTH 1: AGVs and AMRs are completely different machines.

While AMR manufacturers would like you to think otherwise, AGVs and AMRs have very similar functionality. They both transport items to and from a location. Most AMRs focus on transporting totes only, while AGVs tend to focus on full pallet loads. Both can operate in transport-only operation, but AGVs are required for automated picking/lifting, transport, and automatic placement of product.

REALITY: AMRs are really just a subset of AGVs.

The reality is that AMRs are a specific subset of AGVs characterized by navigation technology, physical size/payload capabilities, and routing abilities. When AMR companies compare their products to AGVs, they paint a picture of AGVs as antiquated technology on the verge of obsolescence. This myth is built on the omission of the advances in AGV technology over the last 10 years, such as vision-based guidance, dynamic routing, and 3-D sensors (to name a few).

MYTH 2: All AGVs use wire navigation.

The fundamental difference between AGVs and AMRs involves navigation. When AMR companies compare AMRs to AGVs, they say that AGVs use wire-guided navigation, creating a perception of “old” versus “new” technology.

REALITY: AGVs use the type of navigation that best fits the application.

While historically AGVs would follow routes usually from wires or magnets embedded in the floor of the facility, today’s AGVs use the navigation method that best fits the application. This commonly means laser- or camera-based navigation.

An AGV’s actual navigation path is determined by software directing the machine where to go. The software in an AGV is a combination of fleet management and onboard software. This allows each AGV to know it is on a path and if a path is blocked, other machines can reroute. Some AGVs can adjust their path if an obstacle is blocking a portion of the travel path.

MYTH 3: AGVs use a fixed path.

AGVs travel on a guidepath, but they don’t always take the same path to get from A to B. The guidepath is like a street map, offering many ways to get from one location to another. The AGV software makes intelligent choices based on traffic, travel distance, and other variables to route each machine through the most efficient guidepath of “streets.”

REALITY: AGVs have the capability to use either fixed or dynamic guidepath.

Keeping with the street metaphor, AGVs are like cars and are required to drive on the street (guidepath). ANSI safety standards (the standard that AGVs follow) state that an AGV must travel on a predetermined path. This means the AGV can’t leave the street to use a shortcut, even if there is space for it to fit. AGVs use the streets that have already been determined as the understood travel path. While AGVs are like cars, AMRs are more like bikes in this scenario and are more easily able to exit streets using a shortcut as they would do a lot less damage and take up a lot less space. The difference is that the AMR (bike) can carry a stack of papers or maybe a pizza. The AGV (car) can take 10,000 papers or 900 pizzas. That’s a big difference.

The reality is that AGVs are more like AMRs than you may have been told. Are they different? Yes. But just like kids never want to be told they are ‘just like their parents’, AMRs are more like AGVs than they like to admit.

Part 2 of this 4-part series covers 3 more myths around safety, complexity of work, and ability to work alongside humans. Want to binge it all at once? Download the full AGVs vs. AMRs whitepaper today.

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