The use of industrial robots in factories around the world is accelerating rapidly. Consulting group NMSC forecasts that the global collaborative robot (cobot) market will grow, from 2020 to 2030, at a CAGR of almost 12%.
Meanwhile, according to the 2021 World Robot Report, 126 robots per 10,000 employees is the new average of global robot density in the manufacturing industries – nearly double the number five years ago (2015: 66 units).
THE SEPARATION LINE
Dr Susanne Bieller, general secretary of The International Federation of Robotics (IFR), says what distinguishes cobots from robots is that traditional industrial robots “do not intrinsically carry the necessary safety features to work directly next to humans, but can also be equipped with sensors, cushions etc to work safely alongside human staff”.
So, where do cobots and robots have strict delineations that separate the roles they perform? “There are some tasks that can only be performed by traditional industrial robots, especially with respect to the requirements in reach of the robot arm, the available payload, speed or precision. There typically are some trade-offs, though, where cobots are used, rather than traditional robots.”
It also needs to be critically reviewed whether a cobot or a traditional robot is the best choice, adds Bieller. “There are certain applications that will not be suitable for human-robot collaboration, even if a cobot is used. This, for example, is the case when the robot handles sharp or very heavy objects, or in any welding application that needs safety precautions to safeguard the human from any harm.”
Traditional industrial robots operate in a separate workspace that workers can enter periodically, without having to shut off power to the robot and secure the production cell beforehand – a time-intensive procedure that can be expensive in terms of machine downtime. “The robot’s workspace can be fitted with sensors that detect human motion and ensure the robot works at very slow speeds or stops when a worker is within the designated workspace.”
At the other end of the spectrum are cobots designed specifically to work alongside humans in a shared workspace. “These robots have a variety of technical features that ensure they do not cause harm when a worker comes into direct contact, either deliberately or by accident,” she points out, such as lightweight materials, rounded contours, padding, ‘skins’ [padding with embedded sensors] and sensors at the robot base or joints that measure and control force and speed and ensure they do not exceed defined thresholds, in case of contact. She adds: “In quite a few cases, cobots are not used in a collaborative mode, but rather for their ease of use and ease to set up.”
COBOTS IN ACTION
How exactly are collaborative robots set up to automate a process? Cobots generally consist of a six-degrees-of-freedom manipulator arm and a controller unit, says Antoine Martin, MD and leader of the Autonomous Robotics Systems offering for North America in Industry X at Accenture. Tooling manufacturers offer off-the-shelf products, which can be used for simple processes, whereas complex tasks require custom-designed tools, he adds. In both cases, these tools must meet safety guidelines for collaborative operations: for example, avoiding sharp edges or pinch points.
Once the hardware is set up, the cobot controller needs to integrate with peripherals, such as conveyors or a machine vision system. Industry-standard communication bus systems and platforms can accelerate the integration. Martin continues: “The next step is to program movements and interactions of the cobot with its environment. Robot manufacturers provide offline programming tools to test the program in a virtual environment before on-site deployment. Alternatively, the cobot can be taught by manually adjusting its poses, which it records and then replays. This approach is suitable for tasks requiring lower precision and frequent changes.”
The final step, states Martin, is connecting the cobot to the factory’s manufacturing execution system (MES). “The MES allows the manufacturing station that uses the cobot to react automatically to the quality and efficiency requirements arising during production.”
SYSTEMS INTEGRATOR ROLE
Germane to the cobots’ success has been the systems integrator, although the nature of that role has evolved over time. In its report ‘Demystifying Collaborative Industrial Robots’ (www.is.gd/okifez) the IFR points to how, in the past, systems integrators and internal robot experts have been required to install, programme and operate industrial robots. However, programming interfaces are now increasingly intuitive in both.
“Systems integration experts are still needed for complex applications, and those requiring a redesign of the entire production process,” comments Bieller. “For simpler, stand-alone applications, workers with minimal robot training can now easily re-deploy the robot to a new task. This is particularly important for manufacturers that operate short production runs and need to be able to quickly re-task the robot for a new run.”
That said, the systems integration partner can come with knowledge of both robot technology and the process into which robots are supposed to be integrated. “This means that you would ideally choose a different integration partner, depending on whether you plan to integrate a welding robot for a metal working process or a handling robot for feeding your plastic injection moulding equipment. Especially for companies that are new in robotics, the integration partner will also help to define the requirements and to choose the suitable robot for the specific application. The integrator then also helps with the robot programming and installation [including safety assessment,” Bieller continues.
Then there is the tricky question of change management – what part do cobots play in this? She responds by saying: “I would rather turn it around. What role does change management play when it comes to introducing cobots? Some people – especially those that have not worked with robots before – are quite concerned about their changing roles, so, to have a positive transition, it is important to get the staff involved and support the change process. Change management can help to get all the staff on board, start any necessary upskilling measures and, not least important, take the right steps towards the proper technical integration of the cobots into the manufacturing process.”
Universal Robots is one major player in the cobot market – it has sold more than 50,000 collaborative robots worldwide (an installation is pictured above). “One of the key factors that stops companies investing in new technology is how cost-prohibitive it appears,” it points out. “Rising global energy costs, inflation and higher wage bills are squeezing food and beverage manufacturers’ cost margins and limiting the ability to invest in innovation. But automating tasks is the key to reducing costs and maximising profitability over the long term. Research from Forrester shows that, over the course of a five-year study across French manufacturing firms, the use of robots cut production overheads and led to a 4-6% reduction in labour costs.”