While autonomous mobile robots (AMRs) certainly attract plenty of media attention, not everyone has taken a deep dive into the subject matter. This six-point guide takes you through what mobile robots are, explains how they work and highlights some of the wide-ranging benefits they can offer forward-looking businesses.
Firstly, we need to define what exactly an AMR is. Sometimes referred to as ‘automated mobile robots’, ‘autonomously guided robots’ or simply ‘mobile robots’, AMRs are robotic vehicles that work without any need for human control or intervention. Distinct from – and usually smaller than – automated guided vehicles (AGVs), AMRs typically move dynamically around any obstacles they encounter.
Among a range of advantages, the most obvious one is that AMRs are highly efficient transport solutions that consistently carry out whatever tasks they are programmed to do. Because of their relatively small vehicle footprints and dynamic movement, they work superbly in a range of environments where space is at a premium, including high-tech manufacturing plants and e-commerce fulfilment centres.
Secondly, it is also important at this early stage to outline the differences between AMRs and AGVs. The U.S. National Standard for Industrial Mobile Robots (ANSI/RIA R15.08-1-2020) identifies the difference between the two as being ‘how they traverse the specified operating environment’. According to the standard, an AGV moves through an environment by using predefined virtual or physical guide paths and collision avoidance.
In contrast, AMRs use obstacle avoidance, with the aforementioned safety standard noting that they ‘traverse the specified operating environment by detecting obstacles using sensors and adjusting paths by computing an obstacle-free path through free space, rather than using a predefined path’.
So, in short, AMRs are mobile robots that use natural navigation to move around, largely making obstacle avoidance possible.
Knowledge of how AMRs navigate forms the third part of our guide and, in the vast majority of cases, the autonomous mobile robot navigation technology that these machines use is natural navigation (which is sometimes also referred to as ‘free navigation’).
An AMR’s position and subsequent movement are calculated and controlled using a combination of software and sensors (LiDAR-based laser scanners being one example). Natural navigation allows AMRs to avoid obstacles by creating dynamic alternative routes without the robot losing positioning accuracy or getting lost.
There are, in fact, two main types of natural navigation used by mobile robots today:
- Scan matching (sometimes referred to as ‘SLAM navigation’)
- Feature matching (used by ANT natural feature navigation)
Scan matching technology uses measurements from a vehicle’s laser scanners and compares (‘matches’) them to the cells of a grid-based reference map of the environment. In contrast, ANT feature matching technology uses measurements from a vehicle’s laser scanners and compares them to permanent map reference features, such as walls and pillars. And in case any of these features are not distinct enough, reflective stickers can be added to provide additional references.
The familiar query about whether AMRs are safe is the fourth point. We can provide a very short and snappy answer to this question: yes, they are. That is because they are designed for controlled movements and consistent speeds, while they also incorporate certified safety systems. Automated vehicles such as AMRs, automated forklifts and automated guided vehicles are a safe, highly reliable solution. Unlike humans, robots do not get tired, so they are not prone to making mistakes due to fatigue.
A system’s initial installation – a period of time when routes and actions are tested – is arguably the time when risk is at its highest. Human team members also need this time to get used to using AMRs. Fully briefing staff so that everyone is aware of what the robots are, how they work and how to interact with them is key to minimising risks. Training is therefore vitally important, as is personalising robots with names or faces, both of which can promote staff acceptance of these technologies.
Mobile robots are battery powered, which is our fifth point, and most of them are also designed to dock and recharge at automatic charging stations. And because they do not need to be plugged in manually, they are ideal for 24/7 operation.
The sixth and final focus of our guide is the types of software required to run autonomous mobile robots. AMR operation is based on two main types of software. The first of these is configuration software, typically used by a robot’s integrator (usually its manufacturer or a third-party integrator) when installing these solutions on site. It is used to calibrate a vehicle prior to use for the likes of mapping the site and programming the robot’s routes and actions. ANT lab by BlueBotics, which is used to program ANT-driven vehicles, is one example.
An integrator also configures the second piece of software (mission and fleet management), but it is then used on a day-to-day basis by a robot’s end operator to manage, call and schedule AMR missions. This type of software, such as an ANT server, can often interface with equipment (such as lifts and automatic doors) and a site’s existing WMS/MES/ERP software over APIs.
*This blog article is based on content kindly provided to us by BlueBotics.
