Reaping the benefits of cooperative manufacturing

Humans, cobots and industrial robots are all an important part of the mix in the production environment, but the best option is not always immediately obvious.

The introduction of collaborative robot technology has undoubtedly added tremendous value to smart factory strategies. Where once manufacturers could only consider either fully manual or fully automated operations, cobots have provided the bridge that enables businesses to combine the best of both worlds.

One of the huge benefits of adopting cobots is that it opens up a new paradigm of cooperative manufacturing for the factory of the future, with humans and robots working side by side. It combines the advantages of robotics with the many unique qualities that humans bring to the production environment, including creative and holistic thinking, analytical and synthesis capabilities, and precise manual manipulation skills.

While cobots are undoubtedly proving popular, it is also fair to say that they have added complexity to the decision-making process when specifying equipment, with manufacturers having to solve the challenge of unravelling what will work best for them and the potential trade-offs.

To look at how we navigate this decision-making challenge, we can start by defining some priorities. In particular, we can state with some confidence that the key goals of any factory are:

1. The safety and wellbeing of employees.
2. The assured quality of components and final products.
3. The optimisation of production speed and output.

We must prioritise safety of people as there cannot be any trade-offs in this area. Further, we must focus on quality over production volume because this aspect can boost a company’s reputation and image, creating a valuable relationship with customers. The consequences of poor quality can be significant, and quality problems are completely preventable.

Definitions

Let’s consider the roles of and considerations for human workers, collaborative robots and industrial robots.

Human workers

We have to consider that different workers, be they long-term employees, new hires or seasonal workers, will all have different skillsets, attributes, abilities and training requirements.

Collaborative robots

Cobots are a technology that by definition fulfils the requirements of two key international standards, ISO 10218 and ISO/TS15066. The second of these in particular is hugely important, as it provides detailed guidelines for the use of collaborative technologies.

When we discuss cobots, although they will typically be working with humans, we should not assume that this is the only possible work environment for them. When humans are not present, cobots can have the freedom to work at high speed and with high precision, and do not necessarily need to continue working at slow, collaborative speeds.

Industrial robots

Here we are talking about more traditional robots. These robots will typically operate in an area separated from the human workspace.

Industrial robots with safety scanners

This is an additional category of robot that needs consideration: a standard industrial robot equipped with a safety area scanner. Such technology, fully certified with the appropriate safety standards, allows humans to move around and through the area where robots operate. As the human gets closer, the robot will slow down at the initial approach and stop completely should the human continue to approach.

Considerations for current manufacturing needs

Safety of humans

Safety in a factory is not simply about what safety equipment is being used on the plant floor. It has to be based on a holistic view that encompasses the requirements and likely actions of every employee, and it has to be managed from the bottom up.

When we think about humans working with robots, the collaborative robot is considered an inherently safe option, as defined by the two ISO standards highlighted above. However, the surroundings that the human worker interacts with and handles, for example, need to be considered as part of the cobot installation, and there needs to be a risk assessment to understand if the production process is suitable for adaptation to human–robot collaboration in a safety context.

The traditional industrial robot, due to its speed and footprint, has to be physically separated from that of humans, or the robot needs to be equipped with safety area scanners that recognise the approach and presence of a person and can stop the robot. Selection of an appropriate system depends on the requirements of the application. If the production process is repeatable and doesn’t require changeovers, then an enclosed robot cell might be the right solution. In a low-volume, high-mix production environment where some level of access to the robot work area or interaction with the robot itself is required, then safety scanners can be a better option, significantly increasing overall flexibility.

Production quality

Mistakes in manual assembly can have significant ramifications. But the frequency of such errors can be minimised or even eliminated through:

• thorough and detailed employee training
• poka-yoke (pick to light) solutions that guide an operator’s actions.
   

The effectiveness of these strategies can be further enhanced through automated quality inspection using, for example, high-speed vision systems.

Alternatively, companies can look to automate manual processes; cobots offer the same precision as industrial robots, so production quality can be assured. In addition, cobots can be quickly reprogrammed to handle new tasks, without sacrificing precision.

Among other human–cobot cooperation strategies, cobots can be employed for the inspection of the finished product in a manual assembly process, or the human could be inspecting the work of the cobot. In a lifting and fitting task, the cobot could handle the heavy lifting while the human takes care of the positioning and fitting. In all cases, humans and cobots work together, combining the best attributes of each to deliver the highest quality end product.

For companies looking to automate a complete and repeatable process without the need for regular human interaction, an industrial robot can be the best fit. It will carry out a pre-programmed task with repeatable precision and consistent quality. It can require more time and effort in programming complex tasks, but this only has to be done once. If you have high-volume production, the industrial robot can bring the greatest benefits in terms of quality and volume.

Where volumes are a little lower or where some level of action by human operators within the cell is still required, an industrial robot equipped with a safety scanner can deliver increased flexibility while maintaining the highest levels of quality.

Production volume

The conclusions of production volume considerations are, unsurprisingly, similar to those of the question of quality. While a cobot works much slower than an industrial robot by virtue of the fact that it is cooperating with humans in close proximity, it can still provide a significant production boost. This is especially true if it is allowed to work more quickly when humans are not present, while also using a safety scanner for example.

The greatest production volumes, though, where the process allows it, will always be given by an industrial robot working behind physical barriers. At the other end of the scale, human-only assembly will generally yield the lowest production volumes, even if supported by a poka-yoke guidance system.

Considerations for future manufacturing approaches

Data availability and accessibility

In a state-of-the-art production environment, opportunities for further improvements in speed and quality may not be easy to find. Manufacturers therefore need to look elsewhere to gain additional competitive advantages. One important answer is data: asset data and production information can yield an enormous business advantage.

It is important that the data generated by assets can be easily integrated into the systems that can process them — the likes of edge computers and data science platforms need access to data quickly, fully and with low latency.

To ensure the best practical use of the data, making use of it for decision-making as early in the process as possible is best — as early, in fact, as in the robot itself.

This is where modern robotic technologies bring huge benefits, as the data science is implemented by default in the robotic application as an inherent feature of the robot arm and controller. Robots and cobots can be auto-diagnosed thanks to implementation of AI-driven tools.

When a higher level of analysis is required on data from a greater number of devices, edge-level data science is the next step up, but still close enough to the production environment for real-time decision-making. The edge computer can aggregate and analyse data from a number of different sources, without that data having to leave the environment where most of the manufacturing requirements are handled.

Costs of operation and impact of long-term changes

Present costs and future changes to those costs might be another influence on any production investment decision. The technology footprint of a system is an important factor, and the upfront cost, set-up implications and ongoing training requirements can be a barrier to entry. But the longer-term implications of any decision should be the decisive consideration. Labour costs are rising and will only continue to rise; designing new applications that are built around a reliance on human work might not be a sustainable long-term strategy. Something that today is considered a worthwhile trade-off might become a future burden. And with societies getting older, it might not be long before availability of employees becomes another, and perhaps an even more important, factor.

While there are undoubted costs in embracing technology, it is important to balance the cost of introduction with the benefits to be reaped in the production environment once the technology is up and running. For repeatable, high-volume operation, an industrial robot cell could quickly pay back its higher initial costs, providing the best option. Where high flexibility is required, a cobot will probably be the best option, and provide the lowest cost of entry.

Futureproofing the production strategy

If only one message from this article is remembered, let it be this: there need not be any trade-off made in the choice between cobots and industrial robots.

While cobots can of course be programmed using simple and intuitive visual tools to speed up installation and deployment — undoubtedly a great part of their appeal — they can also sometimes be programmed in the same tools that you’d use with an industrial robot arm. This means that different options can be considered at any time, and production-related decisions are not absolute and inflexible, but can be changed and adapted as required.

In this respect, cobots can be regarded as a bridging technology between an entirely human production environment and an entirely robotised production environment. This is even more the case for cobots that can be run in a higher speed mode in a ‘cooperative production’ setting.

Futureproofing the production environment is built on flexibility. It relies on an appreciation that production requirements may shift over time, and an understanding of how this might happen. It also needs a willingness to consider the way supply and engineering chains might change. You might think that futureproofing the production environment therefore implies a high cost, but the technologies that support the required flexibility don’t have to be expensive.

Another important point to reiterate is that standard industrial robots are much more flexible than they are given credit for. It is true that they require a bit more time for programming and engineering, but they are indeed flexible and can be quickly re-programmed for other tasks. The decisive factor here is your access to the skills needed to program the robots. If you have those skills in your workforce, do not hesitate to invest in industrial robots. If you don’t and if you struggle to find those engineering skills in your area, then cobots might be a more appropriate technology solution, where even someone with no programming skills at all can quickly create effective applications.

Conclusions

In a strategic approach to the evolution of production environments, it makes sense to think ahead. Even strategies that are working well today might not be as effective just a couple of years down the line.

Robots and cobots can be hugely beneficial for production facilities, but even in the most modern factories there is still space for humans, who have unique skills and abilities that are hard to replicate with automated equipment. In order to futureproof your factory you need to make it human-friendly but flexible enough to easily pick the best tool for the highest performance outcome.

Humans, cobots and industrial robots are all an important part of the mix in the production environment, but the best option for a given application is not always immediately obvious. The right solution can deliver huge benefits, immediately and in the longer term. Conversely, a poor choice can lead you down a production blind alley.

Image: iStock.com/Ivan Bajic