“Safety technology is for us the bridge from the industrial robot to the service robot,” says Manfred Gundel, Board Chairman at Kuka Roboter GmbH. Photo: Kroh

What direction is the robotics sector going in? Manfred Gundel, Board Chairman at Kuka Roboter GmbH, sees great potential for growth in the area of service robots. For the Augsburg-based firm, service robotics are therefore not a short-term development but a long-term strategy. Mr Gundel, the Robotics and Automation group of the VDMA (German Engineering Federation) has corrected its prognosis for this year substantially downwards and now expects a minus of 20% in the robotics sector. Has Kuka been hit to a similar extent by the crisis? Gundel: The truth is unfortunately somewhat worse. The robotics sector will not come out of 2009 with a minus of 20%, but will be perform below that. The biggest robot market in the world, Japan, has been floored; there were fall-offs there of 60% in April and May. I expect for Kuka, although it has boosted its market-share, a downturn only half as severe as that of our competitors. Despite the fall-off in the 4th quarter, the German robotics sector increased its turn-over again in 2008 by 15%. How did perform Kuka last year? Gundel: For the Kuka Robotics Group, 2008 was the most successful year in its history, and we were able to raise production to 10 000 robots. The turn-down was already visible in the 3rd quarter, but our annual turn-over increased by more than 10% to 475 mln. Euro.

What do you expect in the future?
Gundel: We have just got to the end of four very retrograde quarters, and I see four similar ones ahead of us, with the whole sector remaining at this depressed level. But my interest is not confined to the next two years; as leaders in technology, we must invest heavily, precisely in a situation like this, to put us in the right position for the next growth phase. Kuka will therefore present innovations once again at next year’s Automatica, and I anticipate that this fair will come at exactly the moment when the market begins to take off again.

Can you reveal a little more about AUTOMATICA?
Gundel: There will be new developments in the areas of both mechanical and control technology. The technology on show here will set the standard for years to come. Mechatronics is one watchword, referring to the integration of machine-tool construction, electronics and software with safety technology. This basic technology will then bring us into service robotics as well.

That is the cue for my next question. According to the statistics of the International Federation of Robotics, the market for service robots will grow more strongly than for industrial robots. Do you see this the same way, and how is Kuka reacting to this trend?
Gundel: We want to be part of setting the course in developing service robots. The first step in our bringing man and robot together was the Robocoaster, the first and still the only industrial robot in the world licensed to carry persons. The next step was the light construction robot made of CFK, aiming at a lighter robot requiring less energy for movement and thus also posing less danger for persons. Our fundamental principle is that safety technology provides the bridge between industrial and service robots. We will continue on this course, for we see a great potential for growth in the area of service robots.

What does Kuka really mean with the term Service Robotics?
Gundel: Under this term, we understand co-operation between man and machine, but also robots on mobile platforms, so that the robot is no longer stationary while working, but has the option of displacement from one workplace to another. Primarily, we envisage service robots in use outside industry, in medical technology, for example, but also in high-skill craft enterprises. And the Robocoaster will certainly remain more than just a flash-in-the-pan in the entertainment industry.

Can you name concrete examples of applications with man-machine co-operation?
Gundel: We have various projects under way with our light-construction robots, but these are not ready for the public yet. Just a word on this: on the one hand, it involves tasks in construction, on the other, medical technology, with the robot supporting human movements. The combination man and machine has to build on its strengths, and man gains advantages from visualisation which surpass anything that is currently available.

When will service robots make a significant contribution to Kuka’s turnover?
Gundel: The question is: how much does one have to invest in order to be able to maintain a place in this market of the future? We are a medium-sized enterprise, and our means are limited. But we can assure you that we are already massively involved in making further advances. But you have to have stamina. Service robotics are therefore for us not a short-term development but a long-term strategy.

Where do you see growing markets for robotics?
Gundel: I would point particularly to medical technology, aerospace and logistics. In the aerospace industry, the main application will be CFK processing, which at the moment is largely manual. To reduce costs, there will be a lot of automation there in the future. Robots will then have to be able to transport complete CFK structures. In logistics, new opportunities will be offered when robots are capable of independent motion on mobile platforms within warehouses.

The automobile industry continues to be the biggest customer for robots. How does the future look for robots there?
Gundel: We do not need to develop any special robots for car makers; what they need is more a building-block principle covering all applications. In addition, the safety aspect is important, as this means that the working area can be reduced and space can be saved.

What share does welding have in Kuka’s total turnover, and what is the situation with seam and dot welding in particular?
Gundel: Every year, 30% of all the robots in the world are used in welding applications. Of these, about half are in dot welding, the other half in gas-shielded welding, with only a minimal percentage in other processes such as laser welding. For Kuka, about 35% of all robots every year go into welding applications. Similarly, the the percentage of dot welding devices is slightly higher than the market average.

How important is the theme energy efficiency for you?
Gundel: In future generations of robots, we will reduce the weight substantially and thus also reduce the energy consumption. This is of advantage to the customer and Kuka accordingly takes it into account in development. Energy consumption is an important point which could be a competitive advantage in the future.

RÜDIGER KROH

Thanks to digital technology, the stamping test cell Videocheck VVC 610 from Vester Elektronik GmbH allows the use of an almost unlimited number of B&W or color cameras with mulit-megapixel image resolution. Image: Vester Elektronik

The quality requirements for stamping products are continually increasing. Threefore it is important to optimize the entire production process from a technical point of view and to integrate suitable test and quality control solutions into production. This trend is characterized by digital image processing systems. Making up an important part of the production chain are fast-acting test cells with powerful image processing that guarantee optimal product quality and provide documention. Thus the new digital stamping test cell Videocheck VVC 610 from the company Vester Elektronik GmbH, in Straubenhardt, Germany, is designed specifically for the requirements of modern manufacturing with short processing times. The PC-based test cell image processing system works with a digital Firewire camera. The high bandwidth and the high processing speed of digital technology guarantee the use of an almost unlimited number of black-and-white or color cameras with mulit-megapixel image resolution. This ensures extremely high detail resolution and measurement accuracy in the µm range.

Simultaneous measurement of many quality characteristics
Thanks to its high performance, the stamping test cell can simultaneous detect a large number of characteristics for testing. Especially in the particularly demanding area of parts production and their quality control, the use of digital Firewire camera technology (IEEE 1394a and/or 1394b) has numerous advantages which would not be possible using analog camera technology.
The Vester test cell is designed as a complete solution based on customer-specific requirements. According to the manufacturer, this guranatees a smooth interaction between lighting, optics, camera, interfaces, computer, image-processing sofware with a user-friendly interface and a connection to process control.

Modular portals reduce setup time during product-line changes
In addition to their standard design, Vester Elektronik also offers rapidly replaceable “change portals.” These modular change portals contain all image processing components with cameras, lighting, stamping strip and drive, as well as separation and marking stations for bad parts. This enables great flexibility in manufacting and minimizes setup time during product-line changes.

Robot with special effectors laying out glass fibres. Photo: Bremer Werk für Montagesysteme GmbH (bwm)

For series production of fibre composite components, suitable automation technology is necessary. For the handling and processing of textile raw materials, for the construction of fibre pre-forms or directing laying out in moulds, a system technology using robotics, sensors, control technology and effectors has been developed. The growth in the use of fibre composite raw materials has been considerable in recent years. Most significantly in aircraft construction, but also in other sectors such as wind energy, ship building or vehicle construction, fibre composites are becoming increasingly important. Their more frequent use in growing markets makes innovative technologies for flexible and quality-orientated fibre composites production necessary.

At the moment, high-performance fibre composite raw materials are produced in various processes based on different pre-products. Predominantly, the production of high-performance composite components is based on either pre-pregs or dry textiles with subsequent resin injection. The production processes are often still controlled manually. Production therefore displays the typical disadvantages of this procedure: limited throughput, high personnel involvement, irregular quality. For series use, the process has to be automated.
For the streamlining of process chains suitable for a variety of processes, the Bremer Werk für Montagesysteme GmbH (bwm) has developed the relevant system technology combining robotics, sensor and control technology and effectors. For handling pre-products, four special grips, for which bwm has obtained the patents, have been incorporated.

The preparation, or preforming, of the textile component part is the precondition for rational production and assured quality of the parts going into the resin injection process. The task facing the bwm development team was to bring their experience in automation technology to bear on the essential steps of fibre composite production: presentation of the semi-finished piece, trimming, handling the trimmed pieces and, in particular, the laying out of the pre-product in moulds.
The various forms of textile reinforcement display a wide range of mechanical properties. Even slight mechanical strain can result in damage to the textile structure. Typical process errors resulting from inappropriate handling of material are changes in angles, wrinkling, distortion and displacement of fibres.
Errors of these kinds are eliminated by controlled laying-out. In a two-stage process chain, Bremer Werk für Montagesysteme made use of its know-how in robot development. Controlled laying-out of dry sheets of fibre textile is effected by means of a recipe-controlled 6-axis robot. Laying-out even of complex contours is enhanced by independent active locating elements. Flexible treatment of successive layers or of different components is achieved using a pre-programmed logistics and cutting module. There are almost no limits to the component geometries achievable using a sixth or seventh axis.

bwm has developed a building-block system guaranteeing adaption to the varied demands in different fields, while simultaneously allowing a continuous expansion of the automatisation in manageable steps. And, importantly, their know-how enables processes such as gelcoat dosage, milling and grinding operations or final varnishing to be incorporated in the chain. These very different challenges depend on the design of the component, the choice of pre-product and the sequence of stages in handling and processing.
As a further step, bwm provides support for the customer in integrating production planning and production processes during the development of the component itself. The aim is to subdivide the complex production process into partial processes, so that processing modules can be developed separately for the precise needs of each partial process.
This methodical approach allows both the installation constuctor and the customer to estimate the productive capacity of the installation at an early stage in the contract phase. Costs and construction time of the installation can thus be reduced. Process modules have already been developed, applied and evaluated for different partial processes.

CHRISTIAN DÖRSCH
Christian Dörsch is Engineering Director of the Bremer Werk für Montagesysteme GmbH, 28239 Bremen.

An advantage of real-time controllers is that sensor-guided SCARA and articulated arm robots can be used with nearly all types of geometries during gluing, deburring, drilling and milling processes. Image: Mitsubishi Electric

Sensor-guided controllers allow industrial robot movements to be directly controlled in production applications. As a prerequisite for this, the robot must allow real-time controlling. For this reason, Mitsubishi Electric has developed a standard real-time controller interface for all SCARA and articulated arm robots. Industrial robots controlled in real-time are able to determine their trajectories while moving and in consideration of momentary sensor values. Here, the controller captures data from ultrasonic, infrared and laser distance sensors as well as from cameras or force/torque sensors, and directly translates these values into the required robot movements. New Mitsubishi interface allows real-time data transfer To control a robot in real-time, data must be transferred rapidly between the sensors and the controller. By default, the robot controllers in the new CRD line from Mitsubishi Electric come equipped with real-time interfaces to communicate with PCs. Via this interface, a PC is able to receive sensor signals, rapidly calculate the position data within just one to ten milliseconds and then send this data back to the robot controller. Mitsubishi Electric offers a real-time controller option for all SCARA and articulated arm robots with load capacities of 6–18 kg or 3–12 kg and ranges of 850 or 1385 mm.

Real-time controllers from Mitsubishi Electric simplify teach-in process for robots
Advantages of real-time controllers: During gluing, deburring, drilling and milling processes, sensor-guided industrial robots can trace a wide variety of different contours and are thus able to handle nearly all possible geometries. It is also easy to manually teach in the position data and trajectories using this type of robot controller.

With six internal and five external axes, the Romat welding robot accesses all welding positions on the component. Photo: Cloos

On an 11-axis robot system, the upper and lower parts of spring elements are welded in a MAG process. Thanks to Roboplan software, the welding programs can be composed off-line and sent to another location by e-mail. What do the visitors’ gallery in the German Parliament building and a car-component manufacturer’s high-speed eccentric press have in common? Both are fitted with application-specific vibration absorbers by the Berlin maker Gerb, eliminating securely undesirable and damaging vibrations. Employing around 400 persons, 140 of them in Berlin, the Gerb group of companies, with bases in Germany, France, Brasil, India and China has an annual turnover of fully 40 mln. Euro. Vibration absorbers by Gerb, in use world-wide “Sometimes we have to play the fire brigade if the planners have underestimated the real vibrations,” says CEO Christoph von Waldow. The fact that the famous Millenium Bridge in London can be crossed in complete safety today, or that non-wobbly television pictures can be transmitted from the visitors’s gallery of the German Parliament building, must be attributed to the competence of this enterprise. For in these locations special vibration absorbers from Berlin are in use. The spring and shock-absorber elements come in sizes up to 1250 mm × 850 mm surface area and 650 mm height. The components, capable of carrying up to 210 t, can weigh up to 1.5 t. “In models with vibration absorption, a special visco-mass combined with perfectly matching shock-absorber geometry make sure that vibrations are damped effectively,” explains production manager Torsten-Uwe Tag.

Two identical welding robots in two works create flexibility
The firm also uses its works in France as an extension of its workbench when the capacities in Berlin are full. “That’s why we have installed two identical robots, here and in Saint Nazaire, so that we can deal flexibly with orders, whether here or there”, the production manager informs us.
Because the Cloos robots are fitted with Roboplan software, welding programs can be composed off-line and sent to the other location by e-mail. “In practice, 90% of the programming is done on the PC on the basis of the CAD construction,” Tag says.
The remaining coordinates and welding parameters are incorporated directly at the robot. “After a successful text run, we transfer the welding program to France by e-mail.” As the robot cell there matches the German installation to the millimetre, the adjustments on site are minimal.
The spring element housings data is transferred from the Gerb CAD installation to the Cloos Roboplan system and processed for the later welding procedures. With the preliminary simulation of the individual welding paths, the first refining and optimising can be carried out.

Roboplan Software calculates coordinates for controlling the robots
In the process, the movements of the robot arm and the spring element housing are determined in the work-piece positioner, taking the welding sequence into account in such a way that the optimum welding seams are achieved at the cost of as little production time as possible. The program calculates automatically the coordinates supplied to the robot control system.
An advantage in working with the Roboplan System is its compatibility with commercially available PCs and its easy operation. “The program can be used after a reasonably short period of training and without extensive knowledge of CAD,” Torsten-Uwe Tag emphasises.

Welding robots have tolerances under control thanks to intelligent tracking of the seam
On the 11 axis Romat robot system, the upper and lower parts of the spring elements – they are formed from the steel types S235 and S355 – are welded using the MAG process. The individual parts of the welded construction have material thicknesses up to 30 mm. These are produced in a flame cutting process. The resulting tolerances, thanks to the welding technique and the intelligent tracking of the seam, cause no problems.
With precision magnet holders, the individual parts of a spring housing are fixed initially on the robot’s rotating tilting table, and are clamped together in a first work process. Next, the Romat 350 welds the interior of the spring element housing before completing the housing by welding the exterior joins.

Welding robots can maintain constant quality in the welding seam
“Depending on the model and the shape of the housing, the installation may need between one and two-and-a-half hours for this,” in Torsten-Uwe Tag’s experience. “With manual welding, a craftsman would have trouble keeping up the desired quality of seam over such a long period.”
In addition, the robot makes an important contribution to a more humane working environment. This is of particular importance to employers, Tag says, pointing to the fitted air extraction unit, which draws off and filters 15 000 m³ of air per hour from the welding shop so that employees can work better in cleaner air. “The air you breathe in our workshops is better than in many a large town,” the production manager is happy to say.

Welding robots and their peripheral systems need only 6 m × 6 m floor area
The compact C Series robot installations need just 6 m × 6 m of floor area and come complete with work-piece positioner, a six-axis robot, wire-feed system and cleaning unit. For optimum operator friendliness, control cubicle and the load-programmed impulse electrical power source GLC 353 MC3 are placed on the periphery.
“We have installed another MC3 so that we can easily carry out necessary manual welding,” the production manager says. Besides this, the third welding unit serves as a spare in case the robot’s impulse electrical power source has to be replaced.

Welding robots provide repetition accuracy of better than 0.1 mm
The six-axle welding robot Romat 350, capable of loads up to 15 kg, works with a repetition accuracy of better than 0.1 mm. It hangs down into the working area from a C pillar, so that the robot arm has optimum access to the welding paths of both internal and external components. Five external axes for handling the work-piece complement the mobility of the welding robot.
The rotating table with its large separating plate enables rational 2-station operation: “While the robot is welding on one side, the operator can prepare the next element for welding on the other side of the positioner or remove a finished element,” Torsten-Uwe Tag explains. His summary: “With the three robot cells, we achieve a consistently high weld quality and, at the same time, take pressure off our employees; thanks to the off-line programming, we can transfer data simply and reliably between our production locations.”

WALTER LUTZ

Correct choice of modules improves plant profitability over the long term. Image: Pfuderer

During the planning phase for automated production facilities, software used to calculate lifecycle assembly costs can also be used to compute the long-term operating costs. Thus, plant concepts can be developed that are optimised for sustainable productivity. In automated production, the degree of flexibility of a plant determines its long-term profitability. It is for this reason that new production facilities typically use a modular design. Modularisation can provide enormous competitive advantages throughout the entire production phase. But in order for this to be true, the various modules must be chosen as accurately as possible with regard to the long-term production cycles to follow. Only then will it be possible to make economical choices consisting of the best possible combination of modules with respect to upcoming use. Thus, it is absolutely necessary to accurately calculate lifecycle costs for a plant. Using the “Lifecycle-xpert” software—originally intended for calculating lifecycle assembly costs for a plant—consultant firm xpertgate from Mannheim, Germany has developed an instrument that can be used by systems engineers to accurately compute the long-term costs of an automated production facility. These costs can be consolidated to determine their cash equivalent. This instrument takes present costs into consideration as well as all future recurring and non-recuring costs . After all, machine profitability has long been determined by other factors than the investment costs.

In today’s production scenarios, the cycle rate, availability, maintenance and energy efficiency are the main criteria affecting profitability. Nearly all of this data can be used in various different ways. In principle, the costs per unit can be broken down by production batch. The various plant parameters can be modified and the anticipated personnel or energy costs can be included.
Each customer provides this data on the basis of their current plant design and plans. Since this instrument can be used to calculate forthcoming production costs, this opens up new perspectives for sub-contractors and component suppliers who can now complete these calculations before submitting their tender to the OEM.
At the beginning of this process, the main data is entered for the planned production facilities. A key factor is the production volume relative to the planned lot sizes as a function of time. This determines how the useful life is allocated over the upcoming years as well as the relationship between the annual operating hours and shifts/workdays. Furthermore, the calculation also includes value-creation quantities such as the costs per unit and material costs. Key costing factors such as imputed interest on equity and borrowed capital are also included in this first step.
Next, specific plant production parameters are taken into consideration such as the cycle rate, technical availability and scrap rate. Various plant costs such as procurement, energy consumption, maintenance and personnel costs round out the remaining data to be entered. At this point, sufficient data has been entered to allow the most profitable concept to be best calculated for a production facility. In practice, these calculations assist systems engineers to compare various designs with each other and to choose the most profitable design over the long term long-term for the customer’s application.

MARKUS PFUDERER
Dipl.-Ing. (FH) Markus Pfuderer is on the board of directors at Pfuderer GmbH and is head of the Project Planning and Engineering division.

The new tape system from Reis Robotics is low-maintenance with few wearing parts. The newly designed application system allows a stress-free application of the tape. Image: Reis Robotics

Reis Robotics, a robotics and assembly specialist based in Obernburg, Germany, presents three new automation systems for the solar technology industry. In addition to lower capital expenditures and production costs, the systems promise improved quality in the production of solar modules.   In recent years, Reis Robotics has designed a wide variety of assembly systems for module production and has supplied them to many well-known solar module manufacturers. The more than 60 systems installed to date have achieved an annual production capacity of approximately 2.5 GW, corresponding to an annual production capacity of more than 12,500,000 modules. The range of services provided by the Obernburg-based robotics specialist include technology development, the development of new manufacturing processes, the planning and implementation of individual machining cells and the delivery and start-up of complete production lines. Both manual systems as well has partially- and fully-automated production lines are offered in the areas of thin film, silicon, and solar-thermal energy.

Fully automated mounting of the junction box
With three new automation systems, Reis Robotics wants to make the manufacture of solar modules more efficient. This includes the fully automated mounting of the junction box. The new system for fully automated placement of the junction box is constructed on a platform as a fully-functional unit and thus can be integrated into any existing production line with a minimum of effort.
The new assembly design has many advantages compared to traditional assembly solutions. According to Reis Robotics, critical work steps before lamination, namely the foil stamping and unrolling of the connection tape are thereby omitted. Furthermore, no EVA can escape during lamination. Membrane fouling is also avoided.

Numerous manual and automatic work steps are omitted
This new method further reduces the danger that the membrane becomes damaged during lamination by protruding ribbons. Since different manual and automatic work steps are omitted and additional material savings are possible, this results in substantial cost advantages according to Reis Robotics. The possible breakage rate is also decreased since manual operations are no longer necessary.
Automatic tape application is new in the Reis technology portfolio for the solar technology industry. The new application system is low-maintenance with few wearing parts. A synchronized drive is used to apply the tape with reduced stress.

Fully automatic splicing can be integrated into the system
This new design permits highly precise cutting of the tape length. Similarly, marking of the adhesive surface on the glass is completed avoided in this design. To enable an uninterrupted change of tape spools, fully automatic splicing can be integrated as an option.
Together with the American silicon specialist Dow Corning, Reis Robotics has introduced encapsulation to the market. For this technology, Reis Robotics is the preferred supplier for Europe, the United States, and Asia.
The encapsulation system offers the following advantages over conventional lamination:

• lower equipment investment
• significantly lower energy consumption
• faster cycle times
• since a complete lamination cycle is not required, outstanding UV stability
• higher module efficiency through better transparency than that of traditional encapsulation materials
• high electrical stability

According to Reis Robotics, this encapsulation system is suitable for silicon cell modules and thin layer glass-glass or glass-foil modules.