Robots for low volume processes

The benefits of robotic automation for mass production processes are well recognised and understood. Visit any modern automotive plant, for example, and you are likely to see rows of robots engaged in a broad range of activities, each playing their own specific role in production.

Even in the UK, where the rate of robotic automation remains stubbornly low, robots are widely acclaimed as being at the heart of the resurgence of the UK car industry, achieving levels of productivity and quality that would never have been thought possible.

With the manufacturing sector still very much at the centre of the Government’s plans for economic recovery, the challenge now is to find ways to convince the UK’s SMEs to make the switch to robots. Accounting for almost 60 percent of the UK’s manufacturing base, SMEs represent a significant opportunity for robot manufacturers, who need to prove that today’s robotic technology is capable of meeting their needs.

Where producers of low volume or bespoke processes are concerned, uncertainty about the suitability of robots would appear to be particularly high. A recent survey by ABB of 221 manufacturing SMEs in the UK showed that almost two-thirds were not currently using robots. Of these, 27 percent identified themselves as operating low volume or bespoke processes which they did not deem as suitable for robotic automation.

In most cases, the arguments against using robots in such processes tend to focus on the perceived operational and financial difficulties involved in adapting a robot to alternate between multiple tasks.

However, this is not to say that using robots in perceived ‘difficult to automate’ processes cannot, and is not, being done. There are an increasing number of examples of companies that are integrating robotic automation into low volume processes across a range of applications, from production of medical devices through to welding and parts handling.

Technology brings new possibilities

Much of what can now be achieved is due to advances in robotic technology, particularly when it comes to a robot’s ‘senses’. Developments in areas such as vision, force sensing and motion control have opened up new capabilities, enabling robots to recognise similarities and differences in the products handled and to respond accordingly.

Advances in offline programming also mean that operators can get a full understanding of what a robot will do without having to disrupt operations on the factory floor. ABB’s RobotStudio software, for example, allows users to program and fully simulate a robotic production process on a PC. Using the software, a program for a new product can be fully tested and fine-tuned, before being uploaded into the robot’s controller, reducing the time to introduce new products to a minimum.

Depending on the process being handled, reported benefits range from improvements in product quality and cycle times both through faster throughput and ‘right first time’ production, through to reductions in wastage.

The best of both worlds

A common misconception is that introducing robots means the end of manual labour. Instead, consideration should be given to how many additional low volume processes could be handled by combining robotic and manual labour, rather than on using robots to handle everything.

Making the change requires a combination of understanding not only what’s possible with current robotic technology but also how to apply it. Ultimately a robot should not be seen as a replacement to a manual worker but rather as a way of making a manual worker more effective. In this regard, a robot becomes a tool which a person can either operate to achieve bespoke products which would not be possible without it or else as way of freeing up that person to perform other tasks.

One such process that lends itself well to human-robot collaboration is welding. Robotic welding not only helps to protect expensive materials from becoming scrap due to bad welds, but can be programmed to operate across a range of similar parts. An example is agricultural machinery manufacturer Shelbourne Reynolds, which successfully created an automation strategy to feature a specially adapted version of ABB’s FlexArc cell. This includes a robot, positioner and the welding equipment needed in an all-in-one integrated package, which is supervised by one member of staff.

With the assistance of ABB, a time study was conducted with estimated time savings being identified for various welding processes in order to identify the ones best suited for the robot cell. Based on the findings of the survey, the use of the cell has expanded beyond the original purpose of producing hedge cutting attachments to also include the production of grain strippers and subassemblies for combine harvester heads.

The result has been a significant reduction in welding times, with products now being welded in one-third of the time previously required. Not only that, but complex welds, such as those involving welding around pipes and tubes, are now performed to a much higher aesthetic standard than previously.

Making the change requires a combination of understanding not only what’s possible with current robotic technology but also how to apply it. Ultimately a robot should not be seen as a replacement to a manual worker but rather as a way of making a manual worker more effective

A knock-on benefit has also been the ability for the company to redeploy its manual welding team to other processes, including fast turnaround tasks and those which are too large for the cell to handle. One example is the manufacture of the stripper header used on larger combine harvester vehicles, which, at 42ft in length, can be produced more economically by manual welders than a robotic cell.

As a small manufacturing operation with limited production space, this has enabled Shelbourne Reynolds to achieve maximum flexibility in its operations and to make best use of the facilities available.

In short, there is no reason why even ‘difficult to automate’ processes requiring flexibility cannot now be resolved using robotic technology.

When successfully implemented, a robot can significantly optimise production and help open up new opportunities, leading to a stronger and more adaptable UK manufacturing industry. Making the switch to a robot requires thorough planning. As specialists in the design and supply of robot systems, ABB and its partners can provide help and advice on the best way to implement robots into a process.

Visit the ABB Robotics website for more information.

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