Al, this is an interesting approach. I looked at their site, and the pdf. It is not really clear how they do it. Are there multiple independent controllers or is one controller programmed to treat each zone independently?
Hello Naperlou, I am in the development department of Bosch Rexroth where this feature is programmed.
The architecture is that there are several controllers: One controller for each tension zone which can be tuned independently. The outputs of these several controllers are combined together within a "decoupling network" in order to achieve decoupling of the tension zones. With that every controller can control "it's own" tension zone independently, i.e. without affecting the tension in all other zones.
This leads to a much more robust system, i.e. a lower tendency for oscillations. The increased robustness can also be used to use "stronger" tension control parameters and therefore achieve a higher dynamic leading to a higher tension accuracy leading to a higher register accuracy. In some applications the only way to get a stable tension is using this decoupling network feature, or to get a tremendous waste which is quite expensive in printed electronic applications. Estimating the yearly waste costs you get when you produce e.g. additional 60-100 feet waste at every machine start is astonishing.
Remark: "A perfect tension is a base – or better – THE base for a perfect register."
The effect is independent of the web speed, i.e. it is present as well in digital printing applications as in printed electronic applications. One of the differences between these two is that in digital printing applications (e.g. inkjet) the printing unit does not affect (= transport) the web so that web tension variations directly influence the register and therefore the decoupling is recommended resp. needed. Printed electronic applications have higher accuracy demands so that best web tension stability is the measure.
See also: http://www.drive-and-control.com/technology/printing-smart-objects
Feel free to contact our colleagues in the US to get more information about our innovative tension control solution.
Naperlou, Many applications can use a single machine controller with groups of axes (forming tension control zone) linked together in software using a combination of electronic gearing, electronic camming and inputs from feedback devices including high speed programmable limit switches, sensors and/or load cells. Each of the zones use software to achieve digital tension control within a specific zone (using distributed processing by running motion algorithms in the servo drives) but each zone is also melded into the overall process as well. Higher performance systems in this area are examples of very sophisticated adaptive control. Hope that helps.
Truchard will be presented the award at the 2014 Golden Mousetrap Awards ceremony during the co-located events Pacific Design & Manufacturing, MD&M West, WestPack, PLASTEC West, Electronics West, ATX West, and AeroCon.
Robots that walk have come a long way from simple barebones walking machines or pairs of legs without an upper body and head. Much of the research these days focuses on making more humanoid robots. But they are not all created equal.
The IEEE Computer Society has named the top 10 trends for 2014. You can expect the convergence of cloud computing and mobile devices, advances in health care data and devices, as well as privacy issues in social media to make the headlines. And 3D printing came out of nowhere to make a big splash.
For industrial control applications, or even a simple assembly line, that machine can go almost 24/7 without a break. But what happens when the task is a little more complex? That’s where the “smart” machine would come in. The smart machine is one that has some simple (or complex in some cases) processing capability to be able to adapt to changing conditions. Such machines are suited for a host of applications, including automotive, aerospace, defense, medical, computers and electronics, telecommunications, consumer goods, and so on. This discussion will examine what’s possible with smart machines, and what tradeoffs need to be made to implement such a solution.