Velocity measurement on roll-fed material and piece goods
Velocity measurement is indispensable for process control and optimization in many industrial processes. It is the basis for many other applications such as cutting length control, length measurement, velocity difference. In these processes velocity is measured using the laser Doppler technique.
Laser surface velocimeters (LSVs) from Polytec are ideally suited because they can conduct measurements on almost any surface and they are not susceptible to contaminated surfaces. The non-contact measuring technique makes it possible to eliminate any negative influences on accuracy, such as slippage and wear, simultaneously. The product being subjected to the measurement remains intact too. Another benefit of Polytec systems is the flexible interface concept – it enables velocity readings via encoder output, serial interfaces, LAN, Profibus and Profinet.
Practical examples
Polytec LSVs are used for various velocity measurement tasks in the paper, cardboard and packaging industry:
- dwell time determination in coating and surface treatment systems
- cutting device control in cut-to-length processes
- coil synchronization when winding sheet materials
Non-contact LSV velocity sensors in paper production
A Polytec LSV is installed in a paper factory because of frequent downtime when changing rolls of paper in its coating machine. Integrating the LSV into the process control allowed rolling velocities to be aligned exactly with one another with an accuracy of 0.1 %. This resulted in a significant reduction of tension fluctuations when joining the paper webs and has already led to savings equivalent to the investment costs in under a year.
Industrial length and speed control with optical sensors
Related products
ProSpeed LSV-2100 Laser Surface Velocimeter
The ProSpeed® LSV-2100 optical sensor determines the direction of motion and standstill conditions with laser precision. It measures reliably even under harsh production conditions with large working distances up to 3 m. Due to the non-contact measurement principle, these laser sensors eliminate common problems of traditional contact-wheel measurement methods such as damage to delicate surfaces, slippage and thermal expansion and work on almost any surface.
ProSpeed LSV-1100 Laser Surface Velocimeter
The ProSpeed® LSV-1100 optical sensor measures in forward direction with laser precision. It measures reliably even under harsh production conditions with working distances up to 1.5 m. Due to the non-contact measurement principle, these laser sensors eliminate common problems of traditional contact-wheel measurement methods such as damage to delicate surfaces, slippage and thermal expansion and work on almost any surface.
Further applications in paper
- Length measurement
![Optical, non-intrusive length measurement of coiled paper]( "Optical, non-intrusive length measurement of coiled paper")
Optical, non-intrusive length measurement of coiled paper - Velocity difference
![Laser precise speed synchronization in slitting processes]( "Laser precise speed synchronization in slitting processes")
Laser precise speed synchronization in slitting processes - Cutting length control
![Cut-to-length control on corrugated board]()
- Position tracking
![Optical position tracking and control for printing processes]( "Optical position tracking and control for printing processes")
Optical position tracking and control for printing processes - Tension control
![LSV sensors enable precise tension control for paper roll exchange processes]( "LSV sensors enable precise tension control for paper roll exchange processes")
LSV sensors enable precise tension control for paper roll exchange processes
