07 December 2012
Look, no guards
Andrew Allcock details an innovative Danish robot design that holds out the promise of lower cost automation for smaller companies in the UK. It is already widely used in mainland Europe
Video shows Danish company BJ Gear, which has automated its gear production
Universal Robot's technology has been hailed "the world's most innovative robot" by the International Federation of Robotics and IEEE (www.ieee.org). Crucially, the technology can be used without guarding, so in collaboration with people; is aimed at small and medium enterprises and is already commonly used in machine/machine tool tending in Europe – but not yet in the UK (RA Rodriguez, 01462 670044).
Indeed, according to the Denmark-headquartered company's Kristian Hulgard, area sales manager for Scandinavia and UK, some 60% of applications for the Universal Robots' technology are in machine tending – the company has around 1,600 installations. According to Mr Hulgard, UK cost for a functioning installation is put at around £30,000 – "Better than half the price of a typical alternative robotic solution."
Universal Robots was founded in 2005 by Esben Østergaard, now chief technology officer, with the declared goal of making robots accessible to small and medium-sized enterprises. The company offers two products – UR5 and UR10, with 5 kg and 10 kg handling capacity respectively (steel weighs around 8 g/cm3, so 625 [ie 5 by 40 cm] or 1,250 cm3 of steel [ie 10 by 40 cm]). The robots have two key elements that make them a safe, lower cost bet.
First, instead of expensive sensor technology, they employ a unique and patented technology to measure electrical current in joints to determine force and movement. Related to this is the second capability, which is to operate with no safety guarding. As soon as a person comes into contact with the robot arm and a force of at least 150 Newton is exerted (just over 15 kg), the robot arm will automatically stop. Importantly, however, companies must still carry out a risk assessment, stresses Mr Hulgard, adding that some 20% of installations do feature guarding of some sort.
Image: Robots that are accessible to small and medium-sized enterprises
MOBILE, SPEEDY SET-UP
Additional key features relate to mobility and programmability. The robots weigh as little as 18 kg, enabling them to be easily moved. Assuming that tasks have already been programmed and that there is some sort of 'zero point' location device to repeat accurate positioning, Mr Hulgard says: "It is only necessary to undo four bolts, relocate the robot and secure it. That can be done in 10 minutes." And location can be on the floor, or on the front or side of the machine, he adds, the latter allowing manned access from the front, for example.
On programming, Mr Østergaard offers: "We decided to make programming intuitive by developing a graphical user interface, combined with a 'teaching function', allowing the user to simply grab the robot arm and show it how a movement should be performed. The robot can be integrated into any production process very quickly. Our experience shows this is generally done in a few hours."
Returning to the key issue of safety, safe operation in accordance with sections 5.10.1 and 5.10.5 of EN ISO 10218-1:2006 (see box item, left) has been verified by Danish Notified Body the Danish Technological Institute – a Notified Body is an organisation that has been nominated by a member of government and Notified by the European Commission to provide EU directive conformance testing, typically relating to safety. The standard's 5.10 section concerns 'Collaborative operation requirements'. Universal Robots' units only operate in collaborative mode. The firm's technology has also recently been granted equivalent USA status (ANSI/RIA R15.06) and saw launch at last September's Chicago IMTS manufacturing technology show.
Users of the company's robots include Lear, Oticon, Bosch, BMW, Scandinavian Tobacco Group, LG, Samsung, LUK and GN Resound. In Asia, the robots are employed extensively by India's Bajaj company in the yearly production of 4 million vehicles, motor cycles and motorised rickshaws (put-puts). This year alone, Universal Robots expects to sell 800-1,000 robots globally, with the UK market being more actively targeted this coming year, Mr Hulgard offers. In Scandinavia, the company already has relationships with machine tool distributors – Haas and Mori Seiki distributors being mentioned in particular.
A machine shop already benefiting from the technology is Danish company Nymann Teknik. Set up in 2010 by Morten Nymann and Jan Rømsgaard, supported by two other investors, the company manufactures various stainless steel parts, drawing its customers from the pump and wind turbine industry, amongST others.
The prompt for considering automation at the small CNC machine shop was a customer request for the machining of 100,000 workpieces on a CNC lathe. It was Mr Rømsgaard, who has 40 years of experience working with robots and automation within the tile industry, who suggested the company take a look at Universal Robots. "The cost is between a third and a fourth of an average annual salary in this country," he explains.
Nymann Teknik paid a visit to one of Universal Robots' distributors to see a demonstration of the UR robot in a test set-up and promptly placed an order for A UR5. The distributor has paid just one visit to the company: to deliver the robot.
"We simply took the robot out of the box and plugged it in," Mr Nymann explains. "After one and a half hours, we had created the first program and after seven hours the robot was working in production. My employees have taught themselves how to program the robot, which paid for itself in a mere three months."
The robot is fitted with two pneumatic catch arms, including adapters, and is set to work for 10-12 hours every single day, feeding a CNC lathe with steel billets. In this particular case, the robot is not run unattended, as Nymann Teknik employees are responsible for finished product quality control.
Image: Nymann Tekni employs Universal Robots' techology for CNC lathe feeding
Concluding, Mr Nymann says: "Solutions with other types of robot will be at least twice as expensive and such an investment would not be affordable for us. To solve tasks like the ones at Nymann Teknik, there are no alternatives to the robots from Universal Robots."
Another Danish company, Linatex, has replaced manual labour with a UR5 unit to feed parts into a CNC turning centre. The company avoided robots, because they were not only too expensive, but also inflexible, as the systems required dedicated and specialist support to convert them to other tasks.
The company processes engineering plastics and rubber for a wide range of industrial sectors, with its products found in everything from artificial hips to aeroplanes and wind turbines. "The operator used to feed parts piecemeal into the CNC turning centre, wait for the machine to complete its cycle, then remove the part," explains Kenneth Midjord from Linatex. "Now the machine can operate unattended until the store of plastic parts is empty."
The robot is used mainly on large production runs of 10,000 pieces, loading and unloading the machine, with the company intending to extend its use to batches down to 50 off. "To use it on other tasks is simple. Our employees can program it themselves, with a little training," explains product manager Jørn Trustrup, who concludes: "It may even have paid for itself after just four months."
Elsewhere, at German company TS Metallbearbeitung GmbH & Co. KG (Thiele), located in Herrenberg, Bavaria, a Universal Robots UR5 is supporting the company's new venture, delivering unmanned machining.
The 10-employee firm primarily makes leak testing equipment, manufacturing parts for them on CNC machining centres. The global financial crisis meant that Thiele had to look to new business areas and the company opted to offer subcontract small series milling. It could not employ additional workers or buy new machinery, however.
The robot has allowed the company to gain one or even two extra shifts, with the ability to move the robot between different machines a key element in this application.
UNMANNED RUNNING OVERNIGHT
At Thiele, once the manned single shift ends, the robot is placed at a milling centre and runs during the night, unmanned. The robot opens machine guards, feeds raw material, fixes it in a machine vice, removes it following milling and puts it aside.
Image: Thiele uses its robots for CNC machining centre loading/unloading, gaining extra shifts
The robot also carries out quality assurance via an imaging system that German systems integrator Faude developed and integrated. The machine vice, previously operated manually, is now automated by means of a pneumatic cylinder that is also connected to the system. No machine constructional changes were required, it is emphasised.
Developed and integrated in just four weeks during January 2010, since then, the system has run without any problems, says the company. The cost for the entire system, including imaging, was covered in 10 months, based on single shifts; seven months, based on two- shift working.
The UK may be about to start catching up with these companies, as Andrew Mason, automation sales manager at UK agent RA Rodriguez (01462 670044), explains: "To date, our main focus has been with the plastics injection moulding industry and also research organisations, including a number of top universities. However, in recent months, we have had a lot of interest from companies looking to use our robot for machine tending. I'm currently working with three potential customers where we are looking at integrating with a vision system to load CNC machines. This is a proven interface in mainland Europe, which we are confident of emulating in the UK."
EN ISO 10218-1:2006, 'Robots for industrial environments —Safety requirements' is the current document that is used to define requirements for safe robot operation. Section 5.10 specifically relates to collaboration mode, meaning a mode in which robots and humans can work alongside each other. A key requirement is the force needed to stop the robot, which is 150 N. A new standard is currently under discussion and development, TS 15066 'Collaborative robots'. This goes into more detail about forces, allying them to location of impact.
Skull/Forehead impact – 175 N; Face – 90 N; Neck (front, larynx) – 35 N; Chest/ribs – 210 N; Belly/abdominal organs – 160 N; Back – 250 N; Upper arm/elbow joint – 190 N; Lower arm/hand joint – 220 N; Thigh/knee – 250 N; Lower leg – 170 N; Feet/toes/joint – 160 N.
The draft new standard calls for a safe distance to be maintained between robot and worker, with the above then being the figures for safe operation, should that safe distance not be maintained. The use of personal protective equipment is also anticipated in the standard as offering a further level of protection.
The HSE earlier this year published a comprehensive report on certain aspect of the new draft standard, in which it noted some concerns. Full copy here
Mr Hulgard underlines that Universal Robots is very focused on keeping up with standards development and that the company's robots will comply with whatever results.
Box item 2
Human-robot developments elsewhere
ABB Robots (01908 350300) offers its SafeMove technology and Fanuc Robotics has its Dual Check Safety system (DSC) that both support safe human-robot interaction. Fanuc Robotics (024 7663 9669) says it complies fully EN ISO 10218-1:2006 – videos explaining the technology can be viewed here (http://is.gd/y0aT5f) for Fanuc, and here (http://is.gd/d6AtnY) for ABB. KUKA Robotics (0121 505 9970) has its LWR 5 robot, which is also intended for use without guarding fences, while a new intelligent safety system from Kawasaki Robotics (01925 713000) provides operators with less restrictive and safer access to robot systems. Called Cubic-S, it is a motion monitoring safety unit that has been awarded TüV Certification to EN ISO 13848-1 performance level d/category 3.
Box item 3
Launched in January this year, SMErobotics (www.smerobotics.org) has as its aim: "A robot that is simple and intuitive to use, without the need for complex programming that learns automatically and interactively from and with its human colleague that 'thinks for itself' and genuinely works together with people rather than just doing its own thing." This follows a predecessor project, "SMErobot", which ran from 2005 to 2009. The current project ends on 31 December, 2015. Cubic S is intended for use with external hardware, such as pressure mates or light guards.
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First published in Machinery, December 20112
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