There’s a difference between AGVs and AMRs and as executives are evaluating them for industry 4.0 initiatives and lean transformation it’s important to understand how these differences can impact your facility in both the short and long term.
See this chart for a quick summary
AGVs are a well known technology used to automate material movement and logistics in highly structured, monolithic and static environments. Introduced back in the 1950s by Barrett Electronics, AGVs haul or tow objects and are used in various industries as a material transportation tool. Although AGVs have historically played a role in the internal logistics of manufacturers worldwide, mobile robot technology has changed considerably. AMRs provide an alternative to the fixed-infrastructure, high startup cost and relatively inflexible use of AGVs.
AMRs in Manufacturing
ABI Research recently published a brief on what they saw at the IMTS 2018 and Hanover Show and here’s there takeaway:
“Cobots and autonomous material handling robots are set to enable a more efficient and zero touch environment that, not only optimizes the shop floor but also extends beyond the line to both ends of the process in the warehouse and eventually into the logistics supply chain”.
Although AGVs and AMRs share use cases in the manufacturing industry, the technology is markedly different. In assessing the difference between these two solutions to automating internal logistics, it’s important to note the primary shortcomings of the older AGV technology: high cost, inefficiency, and limited flexibility.
If we look the characteristics of AMRs, it’s easy to see how they offer advantages over AGVs:
Lower Start Up Cost and More Adaptable
Traditional AGVs typically use specialty signifiers like tracks, wires, tape, and reflectors to navigate. These become fixed references, are required for the initial installation and must be changed whenever a route or delivery scenario changes. AMRs use dynamic digital maps and utilize on board camera and laser-based navigational systems. These AMR features allow the robots to be configured and mapped quickly for a very fast implementation and return on investment (ROI) – typically in a few months. It also allows the robot to be reprogrammed with ease; simply change the route on the digital map
Nearly all AGV systems are designed to work without obstructions and away from people. AGVs are certainly safe in that they will stop when an obstacle is detected; but there they will sit until that obstacle is removed. This is the opposite of AMRs: they were designed from the start to be collaborative. AMRs are able to delivery directly to the point of use – wherever that might be. They can travel the same hallways with pedestrian foot traffic. If an obstacle is detected and there is sufficient room for the robot to travel around it, an AMR will do so and keep the delivery humming along. Some AGV vendors have claimed their systems are more efficient. If there’s any truth to that it’s mainly due to the environment that is required. It should be obvious that any AMR will work more efficiently if such obstacles are not in its path. If AMRs had the luxury of working in a controlled environment like an AGV system the results would be even greater. You would have all the advantages of the lower upfront costs and changeability, along with the unfettered efficiency of an AGV.
When AGVs deliver materials from their depots to their drop-off points, their routes are typically in concrete (figuratively and often literally). This strict guidance system and route definition constrains the manufacturer into that specific path and those fixed drop off or pickup points. AMRs are far more flexible since they use mapping software where a myriad of routes can be established and a fleet management system determines the ideal route for a delivery or pickup.
Coordination and Flow
Most AGVs function independently and must be manually programmed to avoid each other and also do so by virtue of the infrastructure required (tracks). However, a fleet of AMRs employed at a single facility can communicate with each other in order to maximize traffic flow, avoid collisions and jams, and increase operational efficiency. AMRs also should (although not all do) talk to production systems like PLCs. Integration to the PLC system ensures a smooth flow between automation cells. It efficiently pairs the production process with the AMRs and is a real-world internet of things (IoT) solution to a plant’s automation.
The modern manufacturing environment is built with flexibility, automation and connectivity in mind. This is industry 4.0 at its core. When the product mix or manufacturing process needs to change, today’s manufacturers must be able to change with the demands of the market. If your internal transportation is fixed in the routes or fixed in its capacity your flexibility is greatly diminished. AMRs can be reprogrammed on site or even remotely when layouts your routes or delivery needs change. AMR solutions can scale easily and additional mobile robots can be added to the existing facility and instantaneously be put into service using the pre-defined map and routes.
As manufacturers look for ways to adapt to an increasingly volatile business environment that rewards flexibility and efficiency, it’s crucial to employ technology that can adapt in real-time — whether the changes occur in the short-term or over several years. Compared to AGVs, AMRs are perfect for manufacturers whose business models depend on multiple destinations and tasks, with variable frequency, reduced batch sizes and unpredictable workflows.
Regardless of industry, adaptability is key for any business seeking a competitive market position over the coming decade. Autonomous mobile robots (AMRs) allow manufacturers, hospitals, hotels and other businesses reliant on efficient internal logistics to cut excess labor costs and focus on what matters most: The quality of the product or service being provided, and using that quality to drive long-term financial gains.