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Interview with Dr. Thomas Cord, Lenze Automation

Why robot kinematics in machinery industry becoming more important and how Lenze is simplifying their use

Several automation and robot manufacturers supported the market survey from Quest TechnoMarketing about the use of robots until 2018 in the German machinery industry. Lenze, Aerzen, is belonging to them. Thomas Quest speaks to Dr. Thomas Cord, Managing Director of Lenze Automation, about trends in the use of robots.

Foto Dr. Thomas Cord, Managing Director Lenze Automation.
Dr. Thomas Cord, Managing Director Lenze Automation

Dr. Cord, with view of the robot use until 2018 two groups of machine-builders are emerging.

There is the group of those, which already implement robots today. Currently this group almost consists of half of the machine-builders and will increase to 51% until 2018. These machine-builders strive to raise the number of their machines with robots by 46% in the future. So robots have fulfilled their expectations.

At the same time, however, the number of new users of robots will only reluctantly increase with 8%.

So there are two equally large groups facing each other. The one half consists of satisfied robot users while the other half will not even find any access to the use of robots by 2018. Are non-users perceiving robots as large, complex applications, unsuitable for their machines?

„… apart from the classical types of robots there are a great many robot kinematics“

At the time we were dealing with the evolution of our Application Software Toolbox FAST regarding robots, we were thinking for a long time about the robot’s right definition.

We stated that apart from the classical types of robots there are a great many robot kinematics that are adapted to a certain task and that had become a design feature in machinery industry.

Accordingly we specify robots as a serial or parallel linked kinematics with several motion axes for complex three-dimensional movements. So a robot turns out to be the machine’s most flexible and most modular functional unit.

As the interview with Uhlmann Pac Systems confirms, flexibility based on modular machines is becoming crucial for machine-builders.

What means flexibility in connection with the robot use?

The trend in production to ever smaller lot sizes is leading to more special robot kinematics

The default robot will always have its field of applications, for example for stacking beer crates on euro-pallets, i.e. where sufficient workstation and relatively much time are available.

But when it comes to sorting chocolates in trays or placing ampules in blisters, like with Uhlmann, speed and above all handling of most divergent formats play a crucial role. Individualizing the products boosts inevitably the machine’s flexibility up to lot size 1. That in turn is demanding for flexible machine modules.

Concerning the robot constant format changes with small lot sizes leads to special kinematics. Only if this kinematics is specifically adapted to the respective task, highest clock-pulse rates can be achieved.

The machine-builders face the task to standardize the mechanics of their machines ever further. The target is to cover all applications with an overseeable number of modules. Also the manufacturers of grip arms for robots apply for this approach offering a kit of standardized items that can be selected from a catalog.

We, as the automation manufacturer, are also machine-builder and had to learn standardizing our portfolio while covering a very large variety of applications with our mechatronic systems. The Lenze Smart Motor is a good example how a small number of hardware variations is opening up a broad range of application.

This way will also take the robot at the machine. The machine-builder, who cannot use a purchased robot or does not want to, is determined to develop robot kinematics for its applications at the machines. This approach will balance flexibility and speed, being apparently in contradiction.

Even special products can flexibly be produced by adapting the robot kinematics to the handling task. It is possible to adapt the robot’s motion area tightly focused on the machine-builder’s specific requests, small space requirement considered. So robots are becoming integrated very closely into the machine concept not being a foreign body any longer.

Lenze’s control systems also offer the functions of a robotic control besides logic and motion control

Some of our customers already developed outstanding special robots for different tasks, for example articulated arm, portal or also delta robots. However, using robots to a large extent frequently is failing due to time-consuming programming. It does not have to be that way!

That is why we extended our Application Software Toolbox FAST by a complete robotics solution with full robotics core exactly for the kinematics’ control. It offers everything the machine-builder needs for fast and flexible handling engineering.

The robotics core separates completely the kinematics model from the continuous-path control. So the user provides the path as Cartesian coordinates in the work space and describes separately the robot kinematics’ mechanical parameters. Thus robots can be easily projected – completely without robot know-how.

Can you give us some application examples?

How an in-house solution with wood processing machines was made flexible by FAST

Schelling Anlagenbau in Austria carried out the commissioning of wooden plates in a sawing center for the furniture industry by portal axes so far, being separately controlled. This application was an in-house solution.

However, when it comes to kitchens produced according to customer’s individual requests, mass production and batch processing are passé. Each item has to be individually worked on, nevertheless fully automatically produced. For each workpiece new travel paths have to be calculated, possible collisions also detected. The portal robot has particularly to maneuver long sheets in a complex manner around hazard areas. Programming such application nearly by hand with reasonable effort proves to be no longer possible.

Our FAST module „Pick & Place“ completes this task without complex programming. Only the parameters of the application and the coordinates of the start and endpoint of the robot path have to be determined.

Here the application evolved to an individual manufacture with series character thus providing the reason for change to lift the automation on a higher level – without hurting the machine-builder’s complete competence about the machine and its automation.

On the contrary! FAST as toolbox does not take away competence from the machine-builder, in fact, it expands his authority by extending the field of application-specific solutions by the machine-builder.

FAST makes food processing machines flexible

I will pick up another example from the area of confectionery industry. Also this is an outstanding example of a machine-builder’s special application solution.

A robot grips a chocolate with a two-finger grip arm, accelerating and dropping it in a tray. In the course of time the number of product variations had increased while the package sizes reduced. So the grip arm had to be accelerated ever more strongly – up to the point at which the chocolates fell out the grip arm when being accelerated.

What to do? Limiting the acceleration or turning the grip arms by 90 degrees against the acceleration direction? The latter alternative was optimal but not to program by hand in a reasonable effort.

For this application too, FAST enabled both a solution on a technologically higher level and lower engineering efforts for this solution. Now the grip arm, turned by 90 degrees relatively to the path, needs only to be parametrized.

Of course, this works most effectively using Lenze’s integrated total system with control system, converters, motors and gearboxes. The substantial criterion for the system selection, however, concerns the software functionalities.

Even other sectors facing challenge to make machine concepts flexible for smallest lot sizes

The examples given are also relevant for other sectors. In the center point of future development, as mentioned, stands a high flexibility up to lot size 1.  

The sector plastics machines already uses the benefits of robots regarding feeding and dissipating of items. Machine manufacturers of this sector already offer high-grade special robots with application-specific kinematics. This kinematics is optimized to move fast different masses on the condition of a frequent format change.

The variation variety of workpieces up to lot size of 1 will increase in almost all areas. Apart from the highlighted sectors more and more robots will be used in sectors such as the assembly technique, the sheet metal working as well as the glass industry due to their flexibility. These machine-builders will judge even best the special kinematics needed – without reinventing the wheel and without being forced to program the special kinematics.

Lenze is striving for an ever larger focusing on certain applications in the machinery industry in order to simplify the engineering of its customers. Nowadays the crucial point is to bring a machine fast and efficiently to the market – with rising technical complexity. Lenze makes this possible with its solutions.

Dr. Cord, thank you for the interview.

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