Today, robots perform relatively simple handling jobs such as pick-and-place. They operate precisely enough for such applications. However, more and more frequently, complex and flexible operating sequences are required. In addition to repeatability, absolutely exact positioning of the robot tool center point is in focus to an increasing extent in robot engineering today.
 

Laser tracker for observation and verification of robot system behavior.

To date, the objective for applications involving industrial robots was usually simple handling jobs such as pick-and-place in production. For such purposes they were generally designed as simple versions with relatively good repeatability. They were then predestined for such specific jobs. The advantages were flexibility and low procurement costs. Plus the high amortization. Until just recently, the opinion was still widespread that robots were only capable of mastering stupefying, repetitive motion sequences from A to B; in the meantime, the requirements have increased significantly. Complex and flexible operating sequences are required more and more frequently. This frequently results in very special solutions which makes highly precision robots appear mandatory. However, precisely this requirement which appears mandatory contradicts many ideas regarding economic, robot-based solutions. To date, the objective for applications involving industrial robots was usually simple handling jobs such as pick-and-place in production. For such purposes they were generally designed as simple versions with relatively good repeatability. They were then predestined for such specific jobs. The advantages were flexibility and low procurement costs. Plus the high amortization.

Until just recently, the opinion was still widespread that robots were only capable of mastering stupefying, repetitive motion sequences from A to B; in the meantime, the requirements have increased significantly. Complex and flexible operating sequences are required more and more frequently. This frequently results in very special solutions which makes highly precision robots appear mandatory. However, precisely this requirement which appears mandatory contradicts many ideas regarding economic, robot-based solutions.

An important objective is therefore not to redesign or built robots, but rather to concentrate on increasing their accuracy by using innovative methods. This can be achieved with the aid of external measuring technology, actuating elements or special calibration models. This puts the accuracy into dimensions which change today's  concept of robot applications fundamentally from handling systems to highly accurate processing systems.

The trend is in the direction of robot systems with absolute precision and repetition accuracy
Although repetition accuracy was the utmost objective for robot development in the past, this vision has changed more and more to systems with repetition accuracy as well as absolute precision. The robots of tomorrow must master flexible, component-dependent applications requiring more than just continuous repetitions; processes such as deburring, drilling and milling: Whether deburring processes requiring homogeneous and uniform following of different contours or finishing work on molded plastic parts in the automotive sector, where it is necessary to provide functional holes and cutouts in addition to deburring. Therefore, in addition to repeatability, absolutely precise positioning of the robot -TCP (TCP = Tool Center Point), is the focal point to an increasingly greater extent.
Starting with the requirement for highly accurate robot processes, the repetition accuracy represents the barrier for absolute positioning. Here, it is necessary to reduce the systematic error between repetition accuracy and absolute positioning accuracy. This results in the problem of matching the actual characteristics of the robot with the idealized model in the control. The objective is to correct dynamic and static errors.

Dynamic deviations on the TCP result due to load-dependent, thermic and process-dependent deformation of the drives and mechanical structures. On the other hand, static deviations result from geometrically related assembly and production errors such as zero position errors, length deviations and angular errors. Both together represent the relative effects on the positioning of the TCP that require compensation – an absolutely precise system can be produced in this manner.

Iterative development of controllers with D-Space prototyping system
First, it is necessary to record the effects described before they can be used for correction of deviations and, therefore, developing robots with precise positioning characteristics. A D-space prototyping system can be used for standardization so that components and tools already developed in experiments can continue to be used or replaced and controllers can be developed iteratively on the basis of the requirements.

With this background, the Fraunhofer Institute for Production Technology and Automation (IPA) uses the following standard procedure: The nominal tracks are known on the basis of the component or the programming of the robot tracks. The real system relationships are measured and the model parameters identified for active compensation. This serves for measurement of static deviations as well as the dynamic influences resulting from the specific production process. The current position can be checked and corrected with the measurements and the model defined.

External measuring technology makes it possible to observe system behavior
Each specific phase includes the applications for the required auxiliary systems. External measuring equipment makes it possible to observe the system behavior and initialize the next system phases. This includes identification of the robot model or compensation with additional actuating elements which can consist of highly accurate positionable linear or piezo-actuators – for precise action.
In order to satisfy the continuously increasing requirements of machining processes, IPA has dedicated itself to increasing positioning accuracy of industrial robots. With its laboratories equipped with robots, sensors, grippers and measuring systems, it has the best prerequisites for developing intelligent compensation systems for high precision robot applications. Laser trackers and alternative laser measuring systems which make the errors in the robot system measurable and allow verification of the system as shown in Figure 1, can be used for implementation and testing.
As a control system for input variables from observation of the system characteristics, the procedure illustrated in Figure 3 offers a perspective for making conventional robot systems usable for high-precision industrial processes. Each individual component can be applied flexibly to the individual process and application conditions. Verification of the measured or calculated input variables with simultaneous real time compensation through active compensation actuating elements, mechanical modeling and compensation models allows a compensated robot track satisfying tomorrow's requirements for high precision processing.

ARNOLD PUZIK AND MANUEL DRUST
Certified Engineers Arnold Puzik and Manuel Drust are scientific employees at the Fraunhofer Institute for Production Technology and Automation (IPA) in Stuttgart.

For the first time Fanuc Robotics Deutschland GmbH exceeded the mark of selling 2000 robots in 2008.  
 

Gerald Mies, Business Manager at Fanuc Robotics Deutschland GmbH: "In the third and fourth quarter we anticipate an improvement, because demand is present."   Photo: Kroh

"With 2200 robots, were are now clearly number two on the German market," exclaimed Business Manager Gerald Mies. And for the current year he also believes the mark of 2000 robots can be achieved again in spite of the economic crisis. "The 4th quarter of 2008 was like an emergency braking maneuver", according to Mies. Nevertheless Fanuc succeeded in increasing its turnover from 65 to almost 80 million euros. Particularly the general industry, at Fanuc the largest sector with a share of 60%, contributed with an increase of nearly 30%. But the automotive and Tier 1 sector also increased by over 20%. Situation Should Improve by Third Quarter of 2009 Although Mies expects a decrease in turnover for the current year, he anticipates an improvement in the 3rd and 4th quarter. "At the moment many investments are being held back, but demand is still there." Mies considers the food industry and energy sector to be the growth industries. In addition to wind and solar power, he predicts new industries for production of batteries, for example to cover the demand for electric automobiles. Handling will play an important role there. At Fanuc automation of machine tools already has reached a share of 25 to 30% in general industry "However, only about 10% of the potential applications have been exhausted" stated Mies. Above all, because robots have been made intelligent by image processing systems and servo-grippers, flexible charging of machines up to lot size 1 will be possible in the future. However projects are also present in the automotive industry. And here Fanuc is equipping the A-1 body line at the Audi plant in Brussels with several hundred robots.

The year 2008 was excellent for German manufacturers of industrial image processing, assembly and handling equipment as well as robotics: With an increase in turnover of 12% to 9.2 billion euros the branch made significant gains for the third year in sequence. However an managers will have to lower their sights for 2009.

Even though the current crisis will not pass by the highly export dependent German robotics industry without leaving its marks – in the mid-term the growth opportunities for the branch are very good. In picture Robocoaster from Kuka. Photo: Kuka

According to information from VDMA Professional Association for Robotics and Automation particularly the robotics sector contributed to this positive development with a growth rate of 15% for a total of 2.4 billion euros. The background for this high growth was the continuing worldwide trend to automation, according to the association. With growth of 14% totaling 5.7 billion euros, manufacturers of assembly and handling equipment also profited from this trend, thus achieving their best fiscal year to date. Industrial image processing proved to be the most dynamic sector over the course of the year 2008 with growth of an addition 1% to 1.2 billion euros, whereby the economic downturn already began to become apparent the second half of the year. Banking Crisis Hits High Export Branches Particularly Hard In view of their high dependency on export – the export quote is over 50% - robotics and automation were affected particularly by the banking and economic crisis. The simultaneous slump in the economy in all regions of the world is a completely new challenge even for a branch used to dealing with economic upheavals. Based on currently available knowledge VDMA Professional Association for Robotics and Automation predicts a decrease in branch turnover of 6% to 8.7 billion euros in 2009. However for the manufacturers of assembly and handling equipment as well as the robotics sector the losses in revenue are anticipated to be lower (particularly for suppliers of complete systems) due to the number of orders already on hand. Declines are predicted in the range of 5 % to 5.4 and 2.2 billion euros respectively.

Incoming Orders for Robotics and Automation Insufficient
Current the number of orders coming in is "completely unsatisfactory". The fact that the automotive industry and its suppliers are postponing projects and therefore procurement of means of production is becoming noticeable. In 2009 this could affect particularly manufacturers of industrial image processing, which will have to anticipate a decrease in turnover of 15% to 1 billions euros, according to predictions by the association. The reasons are the economically highly declining equipment investments in important user branches such as the automotive industry as well as the electronic, semiconductor and display industry.
German Automation Companies Better Prepared for Slump than Competitors
Nevertheless Dr. Norbert Stein, Chairman of the Board at VDMA Robotics and Automation, is optimistic that the German manufacturers will emerge from the crisis strengthened. "German companies have profited considerably more than their foreign competitors from the increase in the worldwide demand for automation equipment during the last few years. "They have done their homework and are better prepared for the recession than was the case in the 90's, for example.“.
 
VDMA Sees Considerable Mid-term Potential for Automation Equipment
Manufacturers of industrial image processing, assembly and handling equipment and robotics have the best prospective for retuning to the growh path in the mid-term, emphasized VDMA  Professional Association for Robotics and Automation. At VDMA the experts are convinced that manufacturers of consumer products will attempt to stimulate their turnover with attractive new products as well as production cost relevant optimization of their processes. Automation technology will profit from both of these strategic lines of attack.
For the robotics sector, the International Federation of Robotics (IFR) has published long-term predictions, which prescind short-term economic variations: The IFR assumes that the worldwide robot installations will increase by an average of 4% annually by 2011. This mid-term analysis of the demand clearly shows that years of distinct growth will return.
   

From June 8th to 11th, 2010 the AUTOMATICA in Munich will again be the meeting point for the international automation and robotics sector. We spoke with the Anja Schneider, Project Manager for AUTOMATICA about the objectives of the fair, development in the automation branch and highlights at the 4th AUTOMATICA:
Rüdiger Kroh

Exhibition Manager Anja Schneider at Munich International Trade Fairs: "Our objective is to exceed the results of the AUTOMATICA 2008 with 868 exhibitors, if possible. We will just have to see if that is possible in the present, difficult economic situation.

Ms. Schneider, the AUTOMATICA has developed very well since 2004. Do you all see further grow potential for 2010? Schneider: Naturally there is still potential. However we also have a special situation, because our exhibitor and visitor advertising falls right in the middle of the economic crisis. Nevertheless leading suppliers in the automation branch have already decided in favor of the AUTOMATICA again: 15 before the beginning of the fair over 20,000 sq. meters of floor space has already been booked; that amounts to two-thirds of the total area in 2008. Our target is to outdo the results of the AUTOMATICA 2008 with 868 exhibitors. We will just have to see if that is possible in the present, difficult economic situation.   At the previous AUTOMATICA the percentage of visitors from foreign countries was 25%. There is also room for improvement here. What targets have you set for 2010? Schneider: That's right, we also perceive additional potential on the visitor side. In 2008 we were successful in attracting 32,000 visitors from 100 countries; a new record, and we haven't reached the end of the road yet. Here as well our target is to further elevate the level, particularly in terms of the international scope, even though a prognosis is presently difficult. Right now no one can say how long the crisis will last or when the turnaround will arrive. However one thing is clear: We will continue to reinforce our marketing efforts all over Europe and also hold specific campaigns in booming markets such as India and China. We have just kicked off our visitor campaign. With a little bit of luck it will be timed perfectly to reach our visitor branches, such as the automotive branch or the electric and electronics industry, when they begin to recover. Then the AUTOMATICA can serve as a catalyst for investments.   You mentioned the economic crisis. in contrast to other branches the automation sector anticipates only moderate declines during the current year. How will the crisis affect your preparations for the AUTOMATICA 2010? Schneider: Of course the automation branch will not remain unaffected by the economic crisis, particularly in view of the current sales problems in the automotive industry. The current  orders coming in speaks a clear language here. It is therefore very positive that, for example, all leading manufacturers of industrial robots have already registered for the AUTOMATICA 2010 and reserved representative stand areas. We can understand, that many small companies are still holding back and waiting to see what will happen before deciding to exhibit at the fair – but, as already mentioned, we are still on schedule. On the other hand, there are good reasons to believe that automation will emerge from the crisis as a winner. It can contribute to reducing costs, while simultaneously improving products and therefore remaining competitive. Many companies, regardless of the industry, will focus their attention here, when the end of the crisis is foreseeable and it  is time to set the strategic switches for the future. That is why we are not frightened. We look into the future very optimistically, because we are associated with a branch which sets the course for the future. And the AUTOMATICA is an important part of this branch.

The AUTOMATICA is certainly the leading international fair for robotics. There are still gaps in the list of exhibitors for assembly and handling equipment as well a image processing. How do you intend to invigorate this branch?
Schneider: The strength of the AUTOMATICA is that it offers complete solutions for technical production challenges. In the image processing sector, we can score particularly in the areas of system business and robot vision. In the area of automation components we still gaining. We are confident, that more and more component manufacturers will come to Munich. It is only necessary to make them aware that their customers are heavily represented here. That is our mission. 
 
What are the focal points and highlights at the 4th AUTOMATICA?
Schneider: The absolute highlight will certainly be the presentations by the exhibitors, who will play to the gallery with  elaborately designed stands where they can present their innovations and new products. Moreover I would like to accentuate the International Symposium on Robotics, the largest robotics congress worldwide which will be held at the International Congress Center in Munich together with the German Robotics Conference. Nearly 300 participants from around the world are expected. In addition there are numerous events, above all the AUTOMATICA Forum with presentations and podium discussions involving all user sectors. An integral part of the AUTOMATICA is the Innovation Platform for Service Robotics, at which leading robot manufacturers, suppliers and research institutes will present the state-of-the-art in international service robotics. Visitors can touch the robots, try them out themselves and discuss technical details with the developers present. The AUTOMATICA will also illuminate the subject of mechatronics in all its different facets. More information on all these events is available on the Internet at www.automatica-munich.com. We are presently completely redesigning our Website. It is worth while to stay on the ball and check our online offerings frequently.