Are Robots Taking Over our Warehouses?
Updated 30th November 2018
There has been much talk of robots taking the place of humans in warehouses for many years. In fact, some commentators may argue that, with the advent of timed processes, labour management systems, performance monitoring and radio data terminals, many warehouse operatives are already expected to work like robots. Thus real robots may well be much better suited to many of the current warehouse tasks – with humans planning their deployment in accordance with constantly varying demand patterns.
Automation has of course been fairly widespread in warehouses for many decades now, covering such areas as:
- Automated storage and retrieval systems for the storage of pallets
- Miniload systems for the storage of cartons and tote bins
- Automated guided vehicles (AGVs) for the movement of goods
- A-frame dispensers for order picking small cartons
- Advanced conveyor and high-speed sortation systems
- Automated packing machines, pallet loaders, and vehicle loading systems
However, can any of these actually be classified as being a robot? An industrial robot is defined by ISO 8373 as:
An automatically controlled, reprogrammable, multipurpose manipulator programmable in three or more axes, which may be either fixed in place or mobile for use in industrial automation applications.(1)
It could be argued that all of the equipment types mentioned above are automatically controlled and reprogrammable. However, some are not programmable in three or more axes and it is doubtful whether any are truly multipurpose.
More recently, there have been a number of new equipment types that have been introduced under the name of "robots".
One that has gained quite a lot of publicity is the shelf modules-to-picker system using robotic drive units (also known as ‘bots’ or robotic butlers) to bring shelf modules (say about one metre in length and comprising about two to five shelves in height) to a picking station for manual picking. Amazon, for example, has adopted this type of system in a number of their U.S. warehouses.
Another is based on a multi-level grid system whereby tote bins are stored in vertical columns in a grid frame and accessed by multi-wheeled robots running along the top of the frame. These extract the required tote bins and take them to ports at the edge of the grid for onward movement to a picking station.
There are also robotic fork-lift trucks which can put away and extract pallets to and from racking. These are similar in many ways to AGVs but also have a lifting capability. Similar trucks are used to transport pallets along pick faces so that order pickers do not have to drive picking trucks during a pick route.
Examples of robots with arms include robotic picking machines which use grippers or suction pads to pick up items. Improvements in 3-D vision systems are making these technologies more feasible. As with the options of picker-to-goods or vice versa in manual solutions, there is the decision of robot-to-goods or goods-to-robot with this equipment.
A similar application found in warehouses is that of robotic palletisers which can stack tote bins onto wooden pallets or onto dollies (wheeled platforms).
Even though these are all called robots, it is doubtful whether they all fully meet the ISO 8373 definition, particularly with regard to being ‘multipurpose manipulators’ - with the possible exception of some robotic picking machines and palletizers. However, most people probably use a similar definition to one that I found on the internet from a computer 'guru’:
I can’t really define robot. I just know one when I see it.’(2)
Thus, the answer as to whether or not robots are taking over our warehouses is probably in the eye of the beholder.
UPDATE (2018): Are "Cobots" Collaborating with Us in the Warehouse?
Since writing the above about robots taking over our warehouses in 2016, there has been a great deal of interest in warehouse robotics and a large number of new developments in the field. Also, much of the emphasis has changed from robots taking over the jobs of warehouse workers to “cobots” collaborating with warehouse workers.
In order to understand this shift in emphasis, it is necessary to look at some of the advances in the technologies that robots use. These technologies include:
- Advanced location and navigation systems such as LiDAR (Light Detection And Ranging) providing information for SLAM (Simultaneous Localisation and Mapping). These know where they are in a warehouse and can navigate the best way around, even with changing situations such as blocked routes and congested aisles.
- New end effector solutions (e.g. advanced gripper and suction devices) to enable robots to pick up items more effectively.
- Modularisation enabling additional tools to be added easily to robots to increase the variety of warehouse tasks that they can perform.
- Intelligent vision systems, sensors and 3D cameras; so that robots can, for example, see and recognise items in picking locations or see fork pockets in pallets for fork-lift type operations.
- AI (Artificial Intelligence) and machine learning; robots learning the best way to pick up an item when it is oriented in various positions in a picking location.
- VR (Virtual Reality) systems. A person wearing a VR system can teach a robot that basic movements of picking an item and this can then be enhanced by the robot learning how to pick in changing situations through AI.
- Cloud technology (i.e. processing and storing data on remote servers) enables manufacturers to monitor robots (e.g. for breakdowns) in real-time or take over if one has encountered a situation it cannot resolve.
- Industry 4.0, Big Data and the IoT (Internet of Things). Robots can read individual item identifications and update databases through the internet as the status of items is changed. E.g. Item now picked or item outside temperature control limits.
- RPA (Robotic Process Automation) enables the automatic mapping of processes, for example, to link warehouse robot and worker operations to the wider supply chain.
Whilst the basic types of robot have not changed greatly, the technologies that enable robot operations have become far more sophisticated. As these technologies become more widespread (both in the field of robots and in many other fields) their costs are decreasing. Together with warehouse staff recruitment difficulties in many advanced economies, this has led to the investment payback for robots becoming much more attractive.
It was only a few years ago that most industrial robots operated in a caged area away from people. However, the nature of recent technological advances, for example in sensing and navigation, has led to the increasing suitability of robots to work alongside warehouse workers. Examples of “cobots” that work collaboratively with people are robotic drive units that bring shelf units to a manual picking station, autonomous mobile robots (AMRs) that take picked trollies to the dispatch area, and robotic picking trucks (typically also AMRs) that accompany order pickers on their picking run. These latter trucks often include visual displays and put lights (to help locate the items in the correct position on the truck). It may be the case that the robotic truck actually picks the straightforward items and the person picks the more unusual items. The robot could then learn how to pick these unusual items through the use of virtual reality and artificial intelligence.
These trends lead to the question as to whether “cobots” represent the future of warehousing or whether they are merely a step towards full robotisation. The answer will almost certainly depend on the nature of future technological advances, the future costs of robots and the future costs/availability of warehouse staff.
Whatever happens, there will still be a need for people to program, control and maintain the robots – or will there? That is a much wider and more difficult question!
(1) ISO: International Organization for Standardization.
(2) Gordon McComb (amateur robotics guru): http://www.bowlesphysics.com/images/Robotics_-_A_historical_perspective.pdf