Automation takes the efficiency of business operations to another level at all production stages – from internal material flow and manufacturing to logistics of final products in warehouses.
If you are planning to start using automation solutions, you might have seen the terms AGV and AMR. What is the difference between an AGV and AMR? We will share our opinion and explain the distinction.
AGV and AMR
While the term AGV has been used since the 1950s, AMR (stands for Autonomous Mobile Robots) appeared recently and has been gaining prominence over the past years.
- AGV (Automated Guided Vehicle) – this is an automated vehicle that can transfer, load and unload materials.
- AMR (Autonomous Mobile Robot) – AMRs are also used for transferring, loading, and unloading of materials. However, by its name it already implies that this is an autonomous solution that has some degree of independence.
DIFFERENCES AND SIMILARITIES
While “AGVs” and “AMRs” are often positioned as different types of automated vehicles, these terms can be used interchangeably in some cases.
The difference between AGVs and AMRs seems to be defined by the degree of autonomy in selecting the path from the origination point to the destination point. Sometimes, driving around an obstacle is mentioned as a difference between the two vehicle types, which is untrue. This feature depends on the type of navigation only, meaning that the same vehicle can possess or lack the obstacle avoidance feature. In this case, natural feature navigation is the dominant navigation method for driving around an obstacle.
Practically modern AGVs and AMRs use the same navigation technology called natural feature navigation or SLAM (simultaneous localization and mapping).
Historically, there have been navigation techniques that are strongly infrastructure dependent, and the level of dependence is determined by the localization solution. In the case of navigation by inductive wire, magnetic tape, rail, QR-code, laser triangulation with reflectors, or similar, AGVs need artificial infrastructure to operate, and their paths are physically predetermined. For example, with previously mentioned navigation types, the route will be physically set by an inductive wire or magnetic tape on the floor. In such cases, the AGV routes are fixed and changing the layout or adding new vehicles will require updating the infrastructure, which is time-consuming and expensive.
See more about navigation types here
Such types of navigation are outdated and limit the flexibility of certain AGV systems, as they require investments in installation and longer commissioning times. AGVs guided by these navigation solutions will not be able to avoid an obstacle, change their route, or drive off the planned route. They simply will stop in front of an object obstructing their path.
Nevertheless, even traditional AGVs are still capable of choosing the most optimal route or alternative route from the available ones if their AGV system utilizes a fleet-control system, sometimes also called fleet manager. This central fleet management system regulates the traffic considering the length of a possible route and traffic density.
Interestingly, traditional AGV systems still operate with much higher vehicle speeds compared to AMRs and therefore, will provide clearly superior throughput.
This should come as a surprise. Just imagine, if all cars on a road would drive in any direction without any lanes and choose any space they would like to go to freely. The traffic chaos would be incredible, and the driving time to the destination would dramatically increase.
This is exactly what AMRs do. AMR are autonomous vehicles that can freely move from A to B and choose their route by themselves. These vehicles usually navigate with natural feature navigation or SLAM technology (great and modern technology), and they can divert from their individually chosen route in case of an obstacle. Due to their navigation technologies, no or little artificial infrastructure is needed – sometimes, reflector stickers are placed on surfaces depending on the navigation capabilities. But one AMR doesn’t know what the other one is doing, as a centralized fleet-control system is typically missing.
AMRs are fast in commissioning time and require lower investments to set up. It also makes the system flexible, and it’s easy to increase the number of AMRs or make other changes to the system. AMRs are capable of driving freely in an area without any predetermined physical or virtual routes. But the driving speed of an AMR and the throughput of the system, in general, are really low.
THE BEST OF BOTH WORLDS
The modern AGV system or AMRs and AGVs utilize natural feature navigation with driving around the obstacle regulated by capable and user-friendly traffic management or the fleet-control system.
Natural feature or SLAM navigation is not limited to any type of vehicle. It can be utilized anywhere, and certainly in AGVs. Meaning AGVs can also have the same degree of autonomy as any other vehicle including AMRs.
AGVs using natural feature navigation are capable of obstacle avoidance and can change their route if needed. Such AGVs use the same sensors as AMRs to scan the environment. The distinction between AGVs and AMRs becomes very blurry, as both types of vehicles possess similar features. In that case, AGV and AMR terms can be used interchangeably.
AGVs with natural feature navigation don’t require infrastructure to be installed except for reflectors in some cases, and the time for commissioning and installation is short, as compared to other navigation methods. Changing and expanding the fleet of vehicles can be also done quickly, as no major changes in the facilities are needed.
The key to an efficient vehicle automation system is fleet-management. As mentioned earlier, the efficiency of the traffic-regulated and optimized system is much higher than several unmanaged AMRs that try to find their way to their destination, and one doesn’t know where the other one is. Driving around the obstacle or another vehicle always reduces the efficiency of the whole system, as AMRs will start to block each other.
In summary, AGV or AMR systems have much higher efficiency when managed with fleet control. Additionally, driving at least mostly on planned routes will substantially increase the efficiency and throughput of the system.
AGV or AMR – WHAT TO CHOOSE?
Generally, AGVs should be the first choice as this is the most efficient solution in 95% of the applications. AMRs are only of benefit if there is plenty of driving space for several smaller vehicles and the driving speed requirements are very low. The typical application for AMRs is order fulfillment for small low-volume items or a service robot that drive in heavily crowded areas like an airport (among the people).
AGVs and AMRs following virtually predefined routes can be more effective for instance at a large warehouse facility since a high number of completely freely driving AMRs will result in chaotic traffic, and the robots will have to always adjust their paths. At the same time, AGVs or AMRs with natural feature navigation controlled via fleet management software will be assigned an optimal and free route, which certainly will result in higher effectiveness. Planned bypass sections, lanes, etc., will help keep the flexibility high, and at the same time, allow high average driving speeds equal to increased efficiency.
Do you have any questions related to AGV & AMR automation? Contact us, and our team will be happy to talk with you!