EMG strip guiding systems: Know-how for users - 08
Steering rolls with proportional-integral guiding behaviour
In this and the following articles in this series, we summarise know-how on the use of EMG strip guiding systems and try to provide you with the necessary basics for planning the components that can be used and for designing the systems.
Published so far:
- 01 Guiding on the uncoiler
- 02 Guiding on the recoiler
- 03 Strip guidance control before the trimming shear with three-roller steering stand
- 04 Strip centering on welding and stitching machines
- 05 Steering unit with proportional guide
- 06 Radar-based strip center measurement in the furnace with EMG-Vivaldi®
- 07 Optical strip edge / strip centre measurement with EVK / EVM
Steering rolls with proportional-integral (PI) positioning behaviour
Use and application:
A proportional-integral (PI) steering roll is created by combining a proportional and an integral component. PI steering rolls are preferred because this type of steering rolls combines the advantages of the P-model and the I-model. The P component causes a direct correction of the strip and the I component a large error correction via the winding effect with feedback into the infeed section. In the example shown in the picture, the steering roll (type SRH) has the task of transferring the strip into a strip infeed accumulator in the middle of the system. Following a longer free infeed section, a large incoming strip error can be corrected at a 90° deflection roll as described above. The free run-in distance of the SR must be 10 to 15 times the maximum strip width, whereas 2 times the maximum strip width is sufficient for the free run-out distance. For long free inlet and outlet distances, the system can also be used on a 180° deflection rolls.
The swivel frame with mounted deflector roll is guided via two steering levers in such a way that a suitable combination of angular formation between strip and roll axis (I-part) and a lateral displacement of the strip (P-part) results. Thus, in addition to the exact outfeed position of the strip, a centring effect is also achieved in the infeed. In this example, the maintenance-free inductive strip centre measurement type SMI is arranged directly behind the steering roll to detect the strip position.
Of course, PI steering rolls are also used in many other application scenarios. The pictograms on the left side of the picture give a first impression.
Which components are used?
Where can I get support?
Know-how and support in the design, construction and installation of a complete solution for installation in your system can be found in concentrated form at EMG! Our sales and service staff, our international sales organisation or our product manager Martin Wied (firstname.lastname@example.org) can offer you concrete advice on the design of your guiding and sensor solution at any time.
Just contact us!